Clinical Outcomes and Osteoarthritis at Very Long-term Follow-up After ACL Reconstruction: A Systematic Review and Meta-analysis

Revision Anterior Cruciate Ligament Reconstruction: Surgeon-Reported Causes of Failure From the Norwegian Knee Ligament Register

BACKGROUND

Failed anterior cruciate ligament reconstruction (ACLR) leads to reduced quality of life and sometimes the need for repeat surgery. The reason for failure can be multifactorial and difficult to determine. Reports on failure leading to revision are few with limited generalizability. Also, no studies have investigated the reasons for early (<2 years) versus late (≥2 years) revision.

PURPOSE

To describe patients undergoing revision surgery, the surgeon's reported cause of failure, and the risk of undergoing early versus late revision surgery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Primary ACLR cases without concomitant ligament injuries or surgery, registered in the Norwegian Knee Ligament Register from 2004 throughout 2023, were eligible. Descriptive analyses were conducted on intraoperative findings and procedures, time from injury to surgery, activity at the time of injury, revision surgery, surgeon-reported cause of revision, and reporting method. The Kaplan-Meier method was used to calculate revision rates. A multivariable Cox regression model, adjusted for confounders, was used to calculate the hazard ratio of early and late revision surgery.

RESULTS

A total of 30,035 primary ACLR cases were analyzed, of which 1599 resulted in revision surgery. The overall revision rate was 7.1% at 15 years. Female patients were younger at the time of both primary and revision surgery (23.8 and 22.5 years, respectively) compared with male patients (28.2 and 22.2 years, respectively). Age at the time of primary surgery was significantly lower for patients who underwent revision (20.4 years) compared with those who did not undergo revision (26.5 years). Male sex, lower age, hamstring tendon graft, and no cartilage injury at the time of primary reconstruction were all associated with a higher risk of early revision. Lower age, hamstring tendon graft, and no meniscal injury were associated with a higher risk of late revision. New trauma (38.1%) was found to be the most common cause of failure leading to revision.

CONCLUSION

In the current study, representing one of the largest cohorts to date investigating failed primary ACLR leading to revision, the overall 15-year revision rate was estimated as 7.1%. Patients receiving hamstring tendon grafts were at a particular risk for early revision during the first 2 years after primary reconstruction. New trauma was the most common reported cause of failure leading to revision ACLR.

Incidence and Risk Factors for Posttraumatic Osteoarthritis After Primary ACL Reconstruction in Pediatric Patients: A National Database Study

Background

The development of posttraumatic osteoarthritis (PTOA) of the knee after anterior cruciate ligament (ACL) reconstruction (ACLR) leads to additional morbidity in adults.

Purpose

To determine the 5-year incidence of and risk factors for PTOA diagnoses after primary ACLR in pediatric patients.

Study Design

Case control study, Level of evidence, 3.

Methods

A United States-based insurance database was used to identify patients aged ≤16 years who underwent primary ACLR from 2010 to 2019 and had at least 5 years of follow-up data. Patients with multiligament knee injuries, tibial eminence avulsion fractures, congenital/syndromic ACL absence syndrome, juvenile idiopathic arthritis, previous knee osteoarthritis or PTOA diagnoses, or previous knee injuries/surgeries were excluded. Demographic factors and concomitant meniscal and cartilage procedures at the time of primary ACLR were recorded. Delayed ACLR was defined as ≥3 months between initial ACL injury diagnosis and ACLR. We also recorded the presence of subsequent motion restoration reoperations, including lysis of adhesions and/or manipulation under anesthesia, after primary ACLR but before PTOA diagnosis. Risk factors for PTOA were evaluated using multivariable logistic regression.

Results

Included were 16,935 patients (mean age at surgery, 15.1 ± 1.2 years; 62% women). PTOA was diagnosed in 267 patients (1.6%) within 5 years after ACLR; 148 of these patients (55.4%) were diagnosed within 2 years after ACLR. Independent risk factors associated with PTOA diagnosis included subsequent motion restoration procedures (odds ratio [OR], 5.03 [95% CI, 3.31-8.25]; P < .001), age ≥12 years at the time of ACLR (OR, 4.82 [95% CI, 1.54-29.20]; P = .027), delayed ACLR (OR, 1.87 [95% CI, 1.43-2.43]; P < .001), obesity (OR, 1.40 [95% CI, 1.01-1.94]; P = .046), and male sex (OR, 1.36 [95% CI, 1.06-1.74]; P = .015). Performing concomitant partial meniscectomy, meniscus repair, and cartilage restoration at the time of ACLR was not significantly associated with PTOA.

Conclusion

The incidence of PTOA diagnoses was low within 5 years after primary ACLR in patients ≤16 years old with no subsequent cartilage, meniscus, and/or revision ligament procedures. The need for subsequent motion restoration procedures, age ≥12 years at the time of ACLR, delayed ACLR, obesity, and male sex were significant risk factors associated with a PTOA diagnosis.

Reason Profiles for not Returning to Preinjury Activity Level Following Anterior Cruciate Ligament Reconstruction- A Latent Class Analysis With Subgroup Comparison of Patient-Reported Outcome Measures

Background

Given the high proportion of athletes who do not return to sports (RTS) after anterior cruciate ligament reconstruction (ACLR), strategies are needed to identify at-risk patients and optimize rehabilitation for successful RTS after ACLR.

Purpose/Hypothesis

This study used latent class analysis (LCA) to characterize a unique clustering of reasons why athletes do not return to their preinjury activity level after ACLR. We hypothesized that patients with high pain scores and high levels of fear would be less likely to return to their preinjury activity level.

Study Design

Cohort study; Level of evidence, 3.

Methods

All patients at a single institution who underwent primary ACLR between 2005 and 2021 were contacted to complete a survey via REDCap. Patients' ability to RTS and their preinjury activity level, reasons for inability to return to the preinjury activity level, and patient-reported outcome scores were collected from 981 patients. LCA was performed to identify and compare patterns among patients' reasons for not returning to the preinjury activity level.

Results

Of the 981 patients included, only 446 (45.5%) were fully able to return to their preinjury activity level. LCA categorized patients into 3 groups based on their reasons for not returning to preinjury activity levels: a high-function group (75.5%), which reported no barriers; a multisymptom group (16.1%), which cited pain, lack of strength, and instability; and a fear-limited group (8.4%), which reported fear as the sole reason. Among the high-function group, 86.2% reported RTS compared with <36.7% in the other classes. There was no difference in Knee injury and Osteoarthritis Outcome Score (KOOS) subscales-including Pain, Symptoms, or Activities of Daily Living-between the high-function and fear-limited groups; however, the multisymptom group presented with the lowest scores in all KOOS subscales (P < .001). In addition, patient characteristics, the time from the index ACLR to the follow-up, and subsequent revision ACLR were similar between groups; however, the multisymptom profile demonstrated the highest proportion of allograft ACLR (P = .04) and secondary ipsilateral surgery (P < .001). Overall subjective knee grade (1-100) and Marx scores were highest in the high-function group, followed by fear-limited and multisymptom groups (P < .001).

Conclusion

Patients were differentiated into 3 distinct classes after primary ACLR. Furthermore, those with patient-reported characteristics of pain, lack of strength, instability, or fear were significantly less likely to return to their preinjury activity level or sport.

Long-term Outcomes After Anterior Cruciate Ligament Reconstruction With 3 Different Surgical Techniques: A Prospective Randomized Clinical and Radiographic Evaluation at a Minimum of 20 Years' Follow-up

Background

In recent years, lateral extra-articular tenodesis (LET) has been shown to be promising in reducing the graft failure rate at short-term follow-up. However, there is a lack of studies investigating the incidence of complications and lateral osteoarthritis (OA) after this procedure, and only a few studies have reported long-term results after anterior cruciate ligament (ACL) reconstruction.

Purpose/Hypothesis

This study aimed to compare the failure rate, clinical outcomes, and OA incidence of 3 different ACL reconstruction techniques: single-bundle quadrupled hamstring tendon (HT), bone-patellar tendon-bone (BPTB), and over-the-top HT plus LET (HT + LET). The authors hypothesized that the 3 techniques would have comparable clinical and radiographic outcomes at long-term follow-up.

Study Design

Randomized controlled trial; Level of evidence, 1.

Methods

A total of 75 patients were included in this prospective study and randomized to undergo 1 of 3 ACL reconstruction techniques. At the last follow-up (minimum of 20 years), patient-reported outcome measure (PROM) scores, complications, and reoperations were collected, and an objective clinical evaluation was performed, including the measurement of anteroposterior (AP) laxity using an arthrometer and the quantification of the pivot shift (PS) using a triaxial accelerometer. Clinical failure was considered in patients with evidence of a graft rupture or those with a side-to-side difference in AP laxity >5 mm or with a side-to-side difference in the PS >1.5 mm/s2. At the last follow-up, patients also underwent a radiographic evaluation to assess the incidence of tibiofemoral and patellofemoral OA.

Results

PROM scores were collected from 61 patients (81%) at a mean follow-up of 23.0 ± 1.1 years. Of the 75 patients, 37 (49%) completed the clinical evaluation, and 35 (47%) had radiographs obtained. Regarding the PROMs, the HT + LET group showed a slightly higher Tegner score than the BPTB group (P = .023). All other PROM scores were not significantly different between groups. The revision and clinical failure rates were 16% and 37%, respectively, for the BPTB group, 10% and 25%, respectively, for the HT group, and 5% and 19%, respectively, for the HT + LET group, with no statistical difference between the groups. The side-to-side difference in AP laxity was lower in the BPTB group than in the HT group (P = .049). The BPTB group showed a higher patellofemoral OA rate than the HT + LET group (P = .029). There was no difference in the incidence of lateral OA between the 3 techniques.

Conclusion

The 3 different surgical techniques achieved satisfactory clinical outcomes after ACL reconstruction at long-term follow-up. However, the BPTB group was associated with an increased incidence of patellofemoral OA. Also, the HT + LET group was associated with a slightly increased Tegner score at long-term follow-up, but there was no evidence of an increased risk of lateral OA for the HT + LET group.

Patellofemoral joint cartilage lesions frequently develop shortly after anterior cruciate ligament reconstruction using hamstring tendon autograft: A systematic review

PURPOSE

This study aimed to investigate the development of patellofemoral joint (PFJ) cartilage lesions following anterior cruciate ligament reconstruction (ACLR) using hamstring tendon (HT) autograft through a systematic review.

METHODS

A comprehensive search was conducted in PubMed, Embase, Cochrane Library and Google Scholar databases to find articles published from database inception until 15 November 2023. The search terms were [('Anterior Cruciate Ligament' [mesh] OR 'anterior cruciate ligament' OR 'ACL') AND 'reconstruction' AND 'cartilage' AND ('second look arthroscopy' OR 'second-look arthroscopy' OR 'MRI' OR 'magnetic resonance imaging')]. Inclusion criteria were studies that reported on the occurrence of PFJ cartilage lesions following ACLR using HT autograft, as determined by second-look arthroscopy or follow-up magnetic resonance imaging (MRI).

RESULTS

Fifteen studies (1084 patients) met the inclusion criteria, with follow-up periods ranging from 1 to 5 years. In the results of second-look arthroscopy, cartilage grade deterioration was observed, ranging from MDs of 0.1 to 2.0 in the patella and from 0 to 1.0 in the trochlea. Follow-up MRI results reported the incidence of PFJ cartilage degeneration with rates ranging from 20% to 44%. Patient-reported outcome measures often showed no significant association with PFJ cartilage lesions. The studies included in this review reported various risk factors for cartilage lesion development.

CONCLUSION

Cartilage lesions in the PFJ, detected using second-look arthroscopy or follow-up MRI, frequently develop shortly after ACLR using HT autograft. At this stage, patients might not show specific symptoms; however, those with risk factors require careful observation and evaluation by clinicians during follow-up.

LEVEL OF EVIDENCE

Level IV.

In vivo kinematic analysis of failure cases after nonanatomical anterior cruciate ligament reconstruction: a preliminary study

BACKGROUND

Nonanatomical anterior cruciate ligament (ACL) reconstruction occasionally induces ACL failure without an evident injury episode, necessitating revision surgery. Although the in vivo kinematics of ACL deficiency before primary ACL reconstruction are well documented, the kinematics of ACL failure after nonanatomical reconstruction remain unexplored. The aim of this study is to investigate ACL failure kinematics following nonanatomical reconstruction.

PATIENTS AND METHODS

This study enrolled three patients with ACL failure after nonanatomical reconstruction, 20 normal and 16 ACL-deficient knees. The anteroposterior (AP) translation of the medial and lateral femoral condyles and center of the femur and femoral rotation relative to the tibia during squatting were evaluated using a two- to three-dimensional registration technique under fluoroscopy.

RESULTS

Medial AP translation of the nonanatomically reconstructed knee in one patient showed posterior location and abnormal kinematics compared with the ACL-deficient knees. In contrast, the lateral AP position of the nonanatomically reconstructed knees in two patients were more posteriorly located and showed more abnormal kinematics than the ACL-deficient knees. Central AP translation of the nonanatomically reconstructed knees in two patients was located more posteriorly throughout the range of midflexion. Femoral rotation of the nonanatomically reconstructed knees showed abnormal kinematics compared with that of the normal and ACL-deficient knees.

CONCLUSIONS

By independently assessing the medial and lateral aspects of the femur, the medial or lateral condyle of the femur of nonanatomically reconstructed knees exhibited a more pronounced abnormality compared with ACL-deficient knees. The femur of the nonanatomically reconstructed knees showed abnormal rotational kinematics. Considering the kinematic aspect, nonanatomical ACL reconstruction should be avoided.

Anterior cruciate ligament reconstruction with six and eight-strand hamstring tendon autografts produces adequate graft dimensions and functional outcomes: A systematic review

PURPOSE

This study aims to summarize the graft dimensions, failure rates, return-to-sport rates and patient-reported outcome measures (PROMs) following anterior cruciate ligament reconstruction (ACLR) with six or eight-strand hamstring tendon autografts (6SHG or 8SHG).

METHODS

Three databases were searched from inception to 12 February 2024. The authors adhered to PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. All clinical studies reporting patient demographics, objective clinical outcomes and PROMs following ACLR with 6SHG or 8SHG were included for data synthesis. PROMs included the International Knee Documentation Committee (IKDC), Lysholm and Tegner scores.

RESULTS

Thirteen studies comprising 1103 patients were included (mean age: 30.6 years). The transtibial technique was used in all studies, except one study using anatomic ACLR (n = 38), and one study using transtibial and all-inside ACLR (n = 41). Eight studies comprising 512 patients used 6SHG, four studies comprising 507 patients 8SHG and two studies comprising 97 patients used either. Mean graft diameters ranged from 8.0 to 9.2 mm (6SHG) and 9.1 to 9.9 mm (8SHG). Mean graft lengths for 49 6SHG patients ranged from 60.0 to 83.3 mm. The failure rate for 817 patients (6SHG or 8SHG) was 4.8% (0.0%-20.0%). The return-to-sport rate for 112 patients (6SHG or 8SHG) was 75.9% (69.7%-100.0%). Mean IKDC, Lysholm and Tegner scores for 6SHG or 8SHG were 88.4 (86.1-96.3), 91.7 (90.4-96.5) and 6.9 (6.5-7.3), respectively.

CONCLUSIONS

Both 6SHG and 8SHG produced graft diameters <8 mm. Data regarding PROMs suggested good patient satisfaction based on established criteria. Re-rupture and return-to-sport rates were 4.8% and 75.9%, respectively.

LEVEL OF EVIDENCE

Level IV.

Reliability and changes in knee cartilage T2 relaxation time from 6 to 24 months after anatomic anterior cruciate ligament reconstruction

The objectives of this study were to evaluate the reliability of cartilage T2 relaxation time measurements and to identify focal changes in T2 relaxation on the affected knee from 6 to 24 months after anatomic anterior cruciate ligament reconstruction (ACLR). Data from 41 patients who received anatomic ACLR were analyzed. A bilateral 3.0-T MRI was acquired 6 and 24 months after ACLR. T2 relaxation time was measured in subregions of the femoral condyle and the tibial plateau. The root-mean-square coefficient of variation (RMSCV) was calculated to evaluate the reliability of T2 relaxation time in the contralateral knee. Subregion changes in the affected knee T2 relaxation time were identified using the contralateral knee as a reference. The superficial and full thickness layers of the central and inner regions showed good reliability. Conversely, the outer regions on the femoral side and regions in the deep layers showed poor reliability. T2 relaxation time increased in only 3 regions on the affected knee when controlling for changes in the contralateral knee, while changes in T2 relaxation time were identified in 14 regions when not using the contralateral knee as a reference. In conclusion, evaluation of cartilage degeneration by T2 relaxation time after ACLR is most reliable for central and inner cartilage regions. Cartilage degeneration occurs in the central and outer regions of the lateral femoral condyle from 6 to 24 months after anatomic ACLR.

Anterior Cruciate Ligament Reconstruction in Patients Older Than 50 Years: A Descriptive Study With Minimum 10-Year Follow-up

Background

Anterior cruciate ligament (ACL) reconstruction is increasingly being performed in patients >50 years old; however, the long-term outcomes are unclear.

Purpose

To analyze the functional results, osteoarthritic progression, reoperation rate, and failure rate at minimum 10-year follow-up in patients >50 years old who have undergone primary ACL reconstruction.

Study Design

Case series; Level of evidence, 4.

Methods

Included in this study were patients >50 years old who underwent primary ACL reconstruction and had at least 10 years of follow-up data. All patients had instability with limitation of their activities, indicating the necessity of surgical intervention. Patients with revision surgeries, ACL repairs, and nonoperative treatment were excluded. Failure was defined as the presence of revision, high-grade Lachman, positive pivot shift (2+), or subjective instability. The Knee injury and Osteoarthritis Outcome Score (KOOS), subjective and objective functional scores, and osteoarthritic progression were analyzed at final follow-up.

Results

A total of 38 patients were identified. The mean age at surgery was 56.8 ± 5.7 years (range, 50.6-70 years). The mean clinical follow-up was 16.2 ± 4.3 years (range, 10.9-23.3 years). The failure rate was 10.5% (4/38): 1 of the 4 patients had a recurrence of instability at 13 years postoperatively and underwent revision with a modified Lemaire extra-articular tenodesis, 1 patient had a positive pivot shift (2+) without subjective instability, and 2 patients underwent total knee arthroplasty. The overall KOOS was 74.2 ± 22.2, and 91.4% of patients were satisfied or very satisfied with the results of the procedure. Radiographic osteoarthritis was identified in 88.5% of patients at final follow-up; however, there was no statistical significance on clinical outcomes (P > .05). Concomitant partial medial meniscectomy (P < .01) and meniscal repair (P < .01) were associated with the presence of Ahlbäck grade 3 or 4 osteoarthritic manifestations.

Conclusion

In patients over the age of 50 years who underwent primary ACL reconstruction, there was a low long-term failure rate and a high level of patient satisfaction, despite osteoarthritic progression in 88.5% of cases. Concomitant meniscal procedures were associated with more severe osteoarthritic progression.

ACLR and military service: time to rethink?

Anterior cruciate ligament (ACL) rupture is a common injury that affects young, active individuals, normally managed with reconstruction in this age group. Current UK Armed Forces policy precludes prospective applicants from joining with an anterior cruciate ligament reconstruction (ACLR). This isdue to the perceived risk of premature osteoarthritis (OA), graft rupture or clinical failure, all of which could make the service person medically non-deployable.The most recent evidence shows that an ACL rupture without associated significant meniscal or osteochondral defect has a similar likelihood of developing OA as to that of the uninjured knee after reconstruction at 20 years postoperatively.Applicants should be considered for service following an ACL rupture without significant concurrent meniscal or osteochondral defect who have undergone ACLR and 18 months of rehabilitation. We recommend these applicants to be graded P2 Medically Fully Deployable (MFD) as per the Joint Service Publication (JSP) guidance for service personnel who undergo ACLR.

Anterior Cruciate Ligament Reconstruction and Concomitant Focal Cartilage Lesions: A Systematic Review and Meta-Analysis of Prognosis after Surgical Treatment

OBJECTIVE

To synthesize available evidence on the impact of concomitant focal cartilage lesions and their surgical treatment on clinical outcomes in the setting of anterior cruciate ligament (ACL)-reconstruction at short (6-36 months) and midterm (3-8 years) follow-up.

DESIGN

Original level 1 or 2 studies comparing any patient-reported or objective outcomes in ACL-reconstructed patients (1) with and without concomitant focal cartilage lesion(s) or (2) after any type of cartilage surgical treatment were considered for inclusion. Systematic searches were conducted in MEDLINE via Ovid, Cochrane Library, EMBASE via OvidSP, and Web of Science.

RESULTS

In meta-analysis performed across 6 studies (n=8,789 patients), we discovered with very low certainty, the correlation of concomitant any-thickness cartilage lesions and worse Patient-Reported Outcome Measure scores (PROMS) at cumulative short to mid, (pooled standardized mean difference (psmd) = -0.36; 95% confidence interval (CI) -0.62 to -0.10), short (psmd = -0.43; 95% CI = -0.94 to 0.08), and midterm (psmd = -0.22; 95% CI -0.43 to 0.00). Full-thickness lesions predicted worse PROMS with moderate certainty at cumulative short-midterm (psmd = -0.32; 95% CI = -0.41 to -0.23) and low certainty at both short (psmd = -0.45; 95% CI -0.83 to -0.07) and midterm (psmd = -0.30; 95% CI -0.38 to -0.22). In 4 studies for each outcome, mixed results were reported on osteoarthritis (OA) and reoperation rates.

CONCLUSIONS

As the main finding, concomitant full-thickness cartilage lesions in ACL-reconstructed patients are a predictor of worse PROMS in the cumulative short to midterm. Correlations of any-thickness lesions or different cartilage treatments with short- or midterm PROMS, OA, or reoperation rates were either with very low certainty, unmeasured, or with mixed results.

Autograft and Allograft Anterior Cruciate Ligament Reconstruction in Patients Older Than 40 Years Have Similar Short-Term Patient-Reported Outcomes With Greater Rates of Anterior Cruciate Ligament Graft Failure in Patients Who Receive Allograft

PURPOSE

To evaluate short-term patient-reported outcomes (PROs) in patients aged 40 years and older after primary anterior cruciate ligament reconstruction (ACLR) between patients who received allograft or autograft. Secondary aims included assessing the effect of preexisting osteoarthritis on short-term PROs.

METHODS

A retrospective review of an ambulatory surgery center's electronic medical record was conducted for patients who underwent primary ACLR between 2009 and 2022. Patients aged younger than 40 years, those who underwent index revision procedures and/or concomitant ligament repair/reconstructions, and those with incomplete baseline or short-term (1- or 2-year) Knee Injury and Osteoarthritis Outcomes Score (KOOS) scores were excluded. Patients who received allograft or autograft were matched according to sex and body mass index in a 2:1 fashion. PROs used included KOOS and Single Assessment Numeric Evaluation (SANE) at baseline and short-term follow-up (minimum of 1 year). Minimum clinically important difference was calculated in a distribution-based fashion. Osteoarthritis severity was determined on the basis of Kellgren-Lawrence (KL) grading of perioperative knee radiographs. Preexisting osteoarthritis was defined as KL grade 1 or more.

RESULTS

A total of 331 patients were included after matching (215 allograft and 116 autograft patients). The average age was 47.7 ± 6.0 years (range 40-66 years). Age differed significantly between the 2 groups, with the allograft cohort having an average age of 48.6 ± 6.0 years and the autograft cohort having an average age of 46.1 ± 5.7 years (P < .001). Short-term change in KOOS and SANE scores did not differ by graft type (P = .154, P = .556, respectively). Sixty-seven percent of all patients met minimum clinically important difference for KOOS and 82% of patients with complete baseline and short-term SANE scores met minimum clinically important difference for SANE. There was a statistically significant difference in rupture rates between the allograft and autograft cohorts (n = 9 allograft vs n = 0 autograft; P = .030). There was no difference in reoperation rates between the autograft and allograft cohorts (P = .453). Perioperative KL grading did not affect outcomes for either graft type (allograft: P = .905 vs autograft: P = .522).

CONCLUSIONS

Middle-aged patients undergoing ACLR with allograft or autograft demonstrate similar short-term PROs. Preexisting osteoarthritis similarly did not significantly affect short-term outcomes. However, rerupture rates were significantly greater in the allograft cohort than the autograft cohort.

LEVEL OF EVIDENCE

Level III, therapeutic, retrospective, case control study.

Effect of Timing of Surgery on the Outcomes and Complications in Multi-ligament Knee Injuries: An Overview of Systematic Reviews and A Meta-analysis

Background and Aims

Multi-ligament knee injuries (MLKI) are serious and challenging to manage. This study aimed to elucidate the impact of surgical timing on both early and long-term outcomes following an MLKI.

Methods

A comprehensive search strategy was employed across PubMed, Scopus, Web of Science, and the Cochrane Library. Studies were identified using a combination of relevant keywords encompassing "multi-ligament knee injury," "knee dislocation," "reconstruction," "repair," "surgery," and "timing," and their synonyms, along with appropriate Boolean operators. Selection of articles (systematic reviews and meta-analyses) adhered to predefined inclusion and exclusion criteria. Furthermore, a meta-analysis was conducted utilizing data extracted from primary studies.

Results

Early surgery for MLKI demonstrated a significant advantage over delayed surgery, reflected by significantly higher Lysholm scores (Mean Difference [MD] 3.51; 95% Confidence Interval [CI] 1.79, 5.22), IKDC objective scores (Mantel-Haenszel Odds Ratio [MH-OR] 2.95; 95% CI 1.30, 6.69), Tegner activity scores (MD 0.38; 95% CI 0.08, 0.69), and Mayer's ratings (MH-OR 5.47; 95% CI 1.27, 23.56). In addition, we found a significantly reduced risk of secondary chondral lesions (MH-OR 0.33; 95% CI 0.23, 0.48), lower instrumented anterior tibial translation in the early surgery group (MD -0.92; 95% CI -1.83, -0.01), but no significant difference was observed in the secondary meniscal tears, between the two groups. However, the early surgery group also exhibited a significantly increased risk of knee stiffness (MH-OR 2.47; 95% CI 1.22, 5.01) and a greater likelihood of requiring manipulation under anaesthesia (MH-OR 3.91; 95% CI 1.10, 13.87).

Conclusion

Early surgery for MLKI improves function, and stability, and reduces further articular cartilage damage, but increases the risk of stiffness.

Level of Evidence

IV.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-024-01224-1.

Outcomes after multiligament knee injury worsen over time: A systematic review and meta-analysis

PURPOSE

Multiligament knee injuries (MLKIs) are devastating injuries that can have life-long consequences. A management plan requires the decision to perform surgery or not, timing of surgery, consideration of repair versus reconstruction, reconstruction technique and reconstruction graft choice. The purpose of this study was to analyze development of clinical outcomes of MLKIs over time at a minimum of 2 years of follow-up.

METHODS

Four databases were queried for surgical outcome-based studies of MLKIs published from 01/2000 through 09/2022 with a minimum 2-year follow-up. Technique articles, nonoperative treatment, arthroplasty, pediatric and review articles were excluded. Study characteristics including design, number of patients, age, follow-up period, anatomical region and posterior-cruciate ligament (PCL)-based injury were collected. Primary outcomes were Lysholm, International Knee Documentation Committee (IKDC) outcome scores and Tegner activity score. Random-effects model analysis was performed.

RESULTS

After the application of inclusion and exclusion criteria, 3571 patients in 79 studies were included in the analysis. The mean age at surgery was 35.6 years. The mean follow-up was 4.06 years (range 2-12.7). The mean Lysholm score at 2-year follow-up was 86.09 [95% confidence interval [CI]: 82.90-89.28], with a yearly decrease of -0.80 [95% CI: -1.47 -0.13], (p = 0.0199). The mean IKDC at 2 years was 81.35 [95% CI: 76.56-86.14], with a yearly decrease of -1.99 [95% CI: -3.14 -0.84] (p < 0.001). Non-PCL-based injuries had a higher IKDC 83.69 [75.55-91.82] vs. 75.00 [70.75-79.26] (p = 0.03) and Lysholm score 90.84 [87.10-94.58] versus 84.35 [82.18-86.52] (p < 0.01) than PCL-based injuries, respectively.

CONCLUSION

According to the present systematic review and meta-analysis of MLKIs with minimum 2-year follow-ups, the patients who suffered an MLKI can expect to retain around 80-85% of knee function at 2 years and can expect a yearly deterioration of knee function, depending on the score used. Inferior outcomes can be expected for PCL-based injuries at 2 years postoperative.

LEVEL OF EVIDENCE

Level IV meta-analysis.

Location and Progression of Chondral Injuries at the Time of Revision Anterior Cruciate Ligament Surgery Varies by Sex

PURPOSE

To quantify progression of chondral and meniscal injuries between primary and revision anterior cruciate ligament (ACL) surgery.

METHODS

Patients who underwent both index and revision ACL reconstruction between 2000 and 2020 at our institution were identified, and dates of injury and surgery, demographics, and clinical data were obtained from operative reports. Outerbridge grade was recorded in each compartment, along with presence and location of meniscal injury. The frequency of each injury between first and second cases was calculated. Differences in injury and progression were compared over time as well as between patient sex and age.

RESULTS

The study included 189 patients (96 female, 93 male). Age at first surgery was 31.7 ± 13.2 years. Mean time to second injury was 3.3 ± 3.0 years. In total, 116 patients had a new or previous chondral injury (odds ratio, 1.6; 95% CI, 1.2-2.1). The medial femoral condyle (31%) and the patella (21%) accounted for the highest proportion of new injury to articular surfaces, whereas new injury to menisci was comparable between the medial (25%) and lateral (23%) meniscus. At the time of revision ACL reconstruction, females had a high prevalence of chondral injuries to the lateral compartment, whereas males had a high prevalence of chondral injury to the medial femoral condyle. The prevalence of new chondral injuries was comparable between sexes, with males having a slightly higher proportion. While time between surgeries, sex, and age had graphical evidence of moderating risk, the effects were small and imprecise.

CONCLUSIONS

Revision ACL reconstruction carried a 1.6 increase in the odds for new or progressive chondral lesions in our cohort. At the time of revision, females had a relatively higher proportion of lateral-sided chondral injuries, whereas males had a relatively higher proportion of medial femoral condyle injuries. The greatest increase in the prevalence of new and progressive lesions was observed in the medial femoral condyle and trochlea. This progression appeared to be moderated by time between surgeries, patient sex, and age; however, the differences were small and imprecise.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Patient and Operative Risk Factors for Osteoarthritis After Primary Anterior Cruciate Ligament Reconstruction: A Cohort Study of 41,976 Patients

BACKGROUND

The reported incidence of posttraumatic knee osteoarthritis (PTOA) after primary anterior cruciate ligament reconstruction (ACLR) varies considerably. Further, there are gaps in identifying which patients are at risk for PTOA after ACLR and whether there are modifiable factors.

PURPOSE

To (1) determine the incidence of PTOA in a primary ACLR cohort and (2) identify patient and perioperative factors associated with the development of PTOA after primary ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data from the Kaiser Permanente ACLR Registry were used to conduct a cohort study. Patients who had undergone primary ACLR without a previous diagnosis of osteoarthritis were identified (2009-2020). The crude incidence of PTOA was calculated using the Aalen-Johansen estimator with a multistate model. The association of patient and operative factors with the development of PTOA after primary ACLR was modeled as a time to event using multistate Cox proportional hazards regression. Models stratified by age (<22 and ≥22 years) were also conducted because of the effect modification of age.

RESULTS

The study sample included 41,976 cases of primary ACLR. The incidence of PTOA was 1.7%, 5.1%, and 13.6% at 2, 5, and 10 year follow-ups, respectively. Risk factors for PTOA that were consistently identified in the overall cohort and age-stratified groups included a body mass index ≥30 versus <30 and an allograft or quadriceps tendon autograft versus a hamstring tendon autograft. Patients presenting with knee pain after ACLR were further identified when considering postoperative factors. Other risk factors for PTOA in the overall cohort included age ≥22 versus <22 years, bone-patellar tendon-bone autograft versus hamstring tendon autograft, hypertension, cartilage injury, meniscal injury, revision after primary ACLR with concomitant meniscal/cartilage surgery, multiligament injury, other activity at the time of injury compared with sport, and tibial tunnel drilling technique rather than the anteromedial portal.

CONCLUSION

Knee pain after ACLR may be an early sign of PTOA. Surgeons should consider the adverse associations of a higher body mass index and an allograft or quadriceps tendon autograft with the development of PTOA, as these were factors identified with a higher risk, regardless of a patient's age at the time of primary ACLR.

Career Length After Surgically Treated ACL Plus Collateral Ligament Injury in Elite Athletes

BACKGROUND

Limited data are available regarding career length and competition level after combined anterior cruciate ligament (ACL) and medial- or lateral-sided surgeries in elite athletes.

PURPOSE

To evaluate career length after surgical treatment of combined ACL plus medial collateral ligament (MCL) and ACL plus posterolateral corner (PLC) injuries in elite athletes and, in a subgroup analysis of male professional soccer players, to compare career length and competition level after combined ACL+MCL or ACL+PLC surgeries with a cohort who underwent isolated ACL reconstruction (ACLR).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A consecutive cohort of elite athletes undergoing combined ACL+MCL and ACL+PLC surgery was analyzed between February 2001 and October 2019. A subgroup of male elite soccer players from this population was compared with a previously identified cohort having had isolated primary ACLR without other ligament surgery. A minimum 2-year follow-up was required. Outcome measures were career length and competition level.

RESULTS

A total of 98 elite athletes met the inclusion criteria, comprising 50 ACL+PLC and 48 ACL+MCL surgeries. The mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Return-to-play (RTP) time was significantly longer for ACL+PLC injuries (12.8 months; P = .019) than for ACL+MCL injuries (10.9 months). In the subgroup analysis of soccer players, a significantly lower number of players with combined ACL+PLC surgery were able to RTP (88%; P = .003) compared with 100% for ACL+MCL surgery and 97% for isolated ACLR, as well as requiring an almost 3 months longer RTP timeline (12.9 months; P = .002) when compared with the isolated ACL (10.2 months) and combined ACL+MCL (10.0 months) groups. However, career length and competition level were not significantly different between groups.

CONCLUSION

Among elite athletes, the mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Professional soccer players with combined ACL+PLC surgery returned at a lower rate and required a longer RTP time when compared with the players with isolated ACL or combined ACL+MCL injuries. However, those who did RTP had the same career longevity and competition level.

Ensemble Algorithm for Risk Prediction of Clinical Failure After Anterior Cruciate Ligament Reconstruction

Background

Patient-specific risk profiles of clinical failure after anterior cruciate ligament reconstruction (ACLR) are meaningful for preoperative surgical planning and postoperative rehabilitation guidance.

Purpose

To create an ensemble algorithm machine learning (ML) model and ML-based web-based tool that can predict the patient-specific risk of clinical failure after ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 432 patients (mean age, 26.8 ± 8.4 years; 74.1% male) who underwent anatomic double-bundle ACLR with hamstring tendon autograft between January 2010 and February 2019. The primary outcome was the probability of clinical failure at a minimum 2-year follow-up. The authors included 24 independent variables for feature selection and model development. The data set was split randomly into training sets (75%) and test sets (25%). Models were built using 4 ML algorithms: extreme gradient boosting, random forest, light gradient boosting machine, and adaptive boosting. In addition, a weighted-average voting (WAV) ensemble model was constructed using the ensemble-voting technique to predict clinical failure after ACLR. Concordance (area under the receiver operating characteristic curve [AUC]), calibration, and decision curve analysis were used to evaluate predictive performances of the 5 models.

Results

Clinical failure occurred in 73 of the 432 patients (16.9%). The 8 most important predictors for clinical failure were follow-up period, high-grade preoperative knee laxity, time from injury to ACLR, participation in competitive sports, posterior tibial slope, graft diameter, age at surgery, and medial meniscus resection. The WAV ensemble algorithm achieved the best predictive performance based on concordance (AUC, 0.9139), calibration (calibration intercept, -0.1806; calibration slope, 1.2794; Brier score, 0.0888), and decision curve analysis (greatest net benefits) and was used to develop an web-based application to predict a patient's clinical failure risk of ACLR.

Conclusion

The WAV ensemble algorithm was able to accurately predict patient-specific risk of clinical failure after ACLR. Clinicians and patients can use the web-based application during preoperative consultation to understand individual prediction outcomes.

A Preliminary Study of Post-Market Bridge-Enhanced ACL Restoration (BEAR) Suggests Non-Inferior Short-Term Outcomes and Low Complications

Background

To improve outcomes following anterior cruciate ligament (ACL) reconstruction, bridge-enhanced ACL restoration (BEAR) was introduced. Bridge-enhanced ACL restoration uses a collagen-based implant saturated with infused autologous blood to bridge the torn proximal and distal ACL fibers.

Purpose

We sought to analyze the short-term complications, clinical outcomes, and patient-reported outcome measures (PROMs) in patients undergoing BEAR outside of the initial clinical trials.

Methods

We conducted a retrospective cohort study of all skeletally mature patients who had a midsubstance or proximal ACL tear treated with BEAR by 2 surgeons at a single institution and had a minimum follow-up of 6 weeks. A total of 58 patients were included (average age was 38 years, average time from injury to surgery was 45 days). Data on demographic factors, functional outcomes, and complications were collected from electronic medical records. Patient-reported outcome measures and a descriptive return-to-activity survey were analyzed utilizing paired t-tests and Wilcoxon signed-rank tests.

Results

All 58 patients demonstrated a grade of 1A on the Lachman test at 6 weeks postoperatively. At 6 months postoperatively, the mean active flexion was 135° ± 5°, and all patients achieved 0° extension. Although not all patients completed PROM questionnaires, among those who did we observed a significant increase in PROMs between preoperative and postoperative measurements; more than half achieved the minimal clinically important difference in all PROMs, and 26 patients (87%) had a 1-level decrease in function. There were no cases of retear or instability. Three patients (5%) had postoperative arthrofibrosis.

Conclusion

Early results of this preliminary post-market approval study suggest that BEAR may provide a safe and non-inferior approach to ACL reconstruction in selected patients. Studies are needed to investigate the long-term outcomes of this novel technique.

No difference in laxity, proprioception and neuromuscular control after suture-tape augmented ACL repair of acute proximal avulsions versus ACL reconstruction using hamstring autografts in young, active population

Purpose

The purpose of this study is to compare results of suture-tape augmented anterior cruciate ligament (ACL) repair (internal bracing [IB]) and ACL reconstruction (ACLR) with hamstring autograft in terms of laxity, proprioception and neuromuscular control. The hypothesis was that with strict indications IB may provide better results in proprioception and neuromuscular control.

Methods

Patients with unilateral ACL injury treated with IB or ACLR with hamstring autograft were enroled in this retrospective study. Anterior tibial translation (ATT) in 30° and 90° of flexion was measured with Rolimeter. The joint position sense (JPS) test was performed in 30° and 60° of flexion using Biodex System 4Pro. The time-synchronized motion capture system and surface electromyography set were used during dynamic tasks to assess knee valgus and semitendinosus (ST) and biceps femoris (BF) activities. Comparisons between both techniques and operated versus contralateral healthy knees were performed.

Results

The study groups involved 28 patients after ACLR (21.8 ± 4.8 years) and 20 patients after IB (25.8 ± 10.5 years) with the average follow-up 30 ± 18 and 28 ± 15 months, respectively. The ATT did not differ significantly between operated groups. In 30° of flexion ATT for ACLR was significantly higher in operated than in contralateral knee (5.8 ± 2.4 mm vs. 4.3 ± 1.3 mm, p < 0.001). The JPS test and dynamic knee valgus presented no significant differences. The ACLR group presented significantly higher ST (p = 0.048) and BF (p = 0.012) activity comparing operated to contralateral knee in dynamic tasks.

Conclusion

Suture-tape augmented ACL repair and ACLR with hamstring autograft yield similar results in terms of laxity, proprioception and neuromuscular control.

Level of Evidence

Level III: Retrospective comparative study.

A Single-Center, Observational Study Assessing Functional Outcomes After Arthroscopic Anterior Cruciate Ligament Reconstruction Using Suspensory Tibial Fixation With a Polyether Ether Ketone (PEEK) Button

Background Anterior cruciate ligament reconstruction (ACLR) is a crucial procedure in orthopedic surgery. This study evaluates the efficacy and safety of ACLR employing suspensory tibial fixation with a polyether ether ketone (PEEK) button. Methodology This retrospective observational study conducted at Sai Shree Hospital, Pune, India, between November 2023 and December 2023 enrolled 47 subjects aged 18-60 years who underwent arthroscopic ACLR utilizing the T-Button-A Adjustable Loop Ultra-High-Molecular-Weight Polyethylene Suture PEEK button. The functional outcomes and patient-reported outcomes were assessed using the International Knee Documentation Committee (IKDC) score, the Modified Cincinnati Rating System Questionnaire (MCRS), the Single Assessment Numeric Evaluation (SANE) score, the Tegner Activity Level (TAL) Scale, and Knee Injury and Osteoarthritis Outcome Score (KOOS) quality of life subscale. Results Femoral fixation utilized 27 (57.4%) Proloop Ultra Adjustable Loop Button 60 mm, 19 (40.4%) Infiloop Fixed Loop Button 20 mm, and 1 (2.1%) Infiloop Fixed Loop Button 30 mm. Tibial fixation solely relied on T-Button A (PEEK Tibial Button With Adjustable Loop 90 mm). Postoperative evaluations revealed favorable IKDC (79.49 ± 12.67), MCRS (81.32 ± 11.57), SANE (77.83 ± 11.11), TAL Scale (3.87 ± 0.99) and KOOS quality of life subscale (83.81 ± 13.07) scores. Conclusions The findings affirm the efficacy and safety of arthroscopic ACLR utilizing suspensory tibial fixation with the PEEK button, supporting its use for improved patient outcomes.

Hyperbaric oxygen therapy enhances graft healing and mechanical properties after anterior cruciate ligament reconstruction: An experimental study in rabbits

Hyperbaric oxygen therapy (HBOT) has proven successful in wound healing. However, its potential effects on anterior cruciate ligament (ACL) injuries remain uncertain. This study aimed to investigate the impact of HBOT on graft healing following ACL reconstruction in rabbits. Male New Zealand rabbits underwent ACL reconstruction and were randomly divided into two groups: the HBOT group and the ambient air group. The HBOT group received 100% oxygen at 2.5 atmospheres absolute for 2 h daily for 5 consecutive days, starting from the first day after surgery. The ambient air group was maintained in normal room air throughout the entire period. After 12 weeks following the surgery, animals were euthanized, and their knees were harvested for analysis. The HBOT group demonstrated superior graft maturation and integration in comparison to the ambient air group, as evidenced by lower graft signal intensity on magnetic resonance imaging, decreased femoral and tibial tunnel size, and higher bone mineral density values on high-resolution peripheral quantitative computed tomography scans. Additionally, biomechanical testing indicated that the HBOT group had greater load to failure and stiffness values than the ambient air group. In conclusion, the adjuvant use of HBOT improved ACL graft maturation and integration, reduced tunnel widening, and enhanced the biomechanical properties of the graft. These results may provide important insights into the potential clinical application of HBOT as a therapeutic intervention to enhance graft healing after ACL reconstruction, paving the way for further research in this area.

Eighteen-year outcome of anterior cruciate ligament reconstruction with patellar tendon or hamstring autograft

PURPOSE

To evaluate patient reported outcomes and radiographic arthritic changes of transtibial anterior cruciate ligament reconstruction (ACLR) with either bone-patellar tendon-bone (BPTB) or hamstrings (HS) auto-grafts at a minimum of 15-year follow-up.

METHODS

Ninety-four patients (51 of the HS group, 43 of BPTB group) who were operated between the years 2000 to 2005 in two tertiary referral hospitals were contacted and invited to a retrospective evaluation. The interview included subjective outcomes using the Lysholm knee scoring questionnaire, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Tegner activity level scale, Visual Analogue Scale (VAS) for pain and patients' satisfaction scale. Knee examination included measurements of motion and stability. Knee radiographs were evaluated for osteoarthritic changes according to the Kellgren-Lawrence (KL) score.

RESULTS

The average evaluation time from surgery was 18.6 years. Subjectively, there was no significant difference between groups except for a better post-operative level of activity and satisfaction in the HS group. Objectively, there was no significant difference between groups in knee stability and range of motion. Most patients had grade KL ≤ 1 radiographic osteoarthritits changes and there was no significant difference between groups. Recurrent complete tear of the reconstructed graft occurred in 3 patients of each group. In both groups 84% had no further surgery while the indications for further surgery were mostly a meniscal tear or tibial hardware removal.

CONCLUSIONS

Very long-term outcomes and clinical stability of transtibial HS or BPTB graft ACL reconstruction are good with low rate of graft failure and radiographic osteoarthritis.

Comparison of Cross-Pin Versus Cortical Button Femoral Fixation in Anterior Cruciate Ligament Reconstruction With Hamstrings Autograft: A Long-Term Clinical Study and Review of the Literature

Background Anterior cruciate ligament reconstruction (ACLR) is a common operative procedure and many options regarding the type of the selected graft and fixation technique have been described to date. Although many studies have addressed the issue of the optimal femoral fixation device during ACLR with a hamstring tendon (HT) autograft, no clear evidence to indicate one technique over another has been found. Objective The purpose of this study was to compare the long-term postoperative outcomes and complication rates between transfemoral Cross-pin (CP) and Endobutton-Cortical Button (CB) fixation techniques in patients undergoing ACLR with an HT autograft. Methods One hundred and seven consecutive patients underwent ACLR by using a quadruple HT autograft that was stabilized with either a CP (CP Group: 52 patients) or a CB (CB Group: 55 patients) fixation technique. The Lachman test (LT), the Pivot-shift test (PST), the side-to-side difference in anterior translation of the tibia, the International Knee Documentation Committee (IKDC), and the Lysholm knee scoring systems were evaluated before surgery and during long-term follow up. The femoral and tibial tunnel diameter was measured in the anteroposterior (AP) and lateral radiographs after surgery and at the final follow-up. A review of the literature was also carried out to identify any differences between both techniques. Results Study groups were comparable in terms of patient demographics. The mean follow-up was 10.4 ± 1.3 and 10.6 ± 1.3 years in the CP and CB Groups, respectively (p = 0.47). In the CP Group, improvements after surgery in LT and PST from grade 2 (n=34) or 3 (n=18) to grade 0 (n = 41) or 1 (n = 11) and from grade 2 (n=36) or 3 (n = 16) to grade 0 (n = 44) or 1 (n = 8), respectively, were observed. In the CB Group, similar improvements in LT and PST scores from grade 2 (n = 40) or 3 (n = 15) to grade 0 (n = 46) or 1 (n = 9) and from grade 2 (n = 41) or 3 (n = 14) to grade 0 (n = 47) or 1 (n = 8), respectively, were observed. However, no differences between the groups (p = 0.53 for LT and p = 0.90 for PST) were noted. The mean Lysholm scores were 89.7 ± 6.8 and 90.2 ± 7.2 in the CP and CB groups, respectively (p = 0.59). Side-to-side difference improved from 9.1 ± 2.8 to 1.7 ± 1.5 mm and from 8.6 ± 2.5 to 1.6 ± 1.4 mm in the CP and CB groups, respectively (p = 0.89 between groups). According to IKDC grades, 92.1% and 91.4% of knees in the CP and CB groups, respectively were reported to be Grade A (Normal) or B (Nearly Normal) with a p = 0.7. Femoral and tibial tunnel widening was found in the last follow-up in both groups. However, there was no difference in the degree of tunnel widening among the two techniques. With respect to LT, PST, anterior drawer test, and IKDC score, none of the 15 published comparative studies demonstrated any significant differences between the two techniques and only one study detected a difference regarding the Lysholm score in favor of CP fixation. Conclusion In the long term, both CB and CP femoral stabilization techniques were shown to be associated with similar functional outcomes and low complication rates. Further large multicenter random clinical trials are still required to identify the most effective method of femoral fixation for HT autograft during ACLR surgery.

A slight degree of osteoarthritis appears to be present after anterior cruciate ligament reconstruction compared with contralateral healthy knees at a minimum of 20 years: A systematic review of the literature

Purpose

The aim of the present systematic review was to quantitatively synthesize the best literature evidence regarding osteoarthritis developing after anterior cruciate ligament reconstruction (ACLR), including only studies with a follow-up duration of at least 20 years.

Material and Methods

A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines on four electronic databases (PubMed, Scopus, EMBASE and Cochrane Library). The outcome measures extracted from the studies were failure rate, subsequent knee surgery on the same knee, radiographic development of osteoarthritis measured with Kellgren-Lawrence, International Knee Documentation Committee (IKDC) radiographic score and Ahlbäck classification. The health of both the ACLR knee and the contralateral knee was compared.

Results

A total of 1552 patients were included in the study, of which 1290 (83.11%) were operated on using a patellar tendon graft, 190 (12.24%) with hamstrings, 27 (1.73%) with an iliotibial band and 45 (2.89%) with patellar tendon plus a ligament augmentation device (LAD). The mean age at the time of surgery was 25.18 ± 1.91 years, and the mean follow-up time was 23.34 ± 2.56 years. Analysing IDKC Score at final follow-up, ACLR Group showed a higher degree of OA compared with contralateral healthy knee (p < 0.01), but only 33.2% (324/976) of the patients showed a moderate to severe degree (Grade C or D) of osteoarthritis, while for Kellgren-Lawrence, ACLR Group showed a higher degree of OA compared with contralateral healthy knee (p < 0.01), but only 28.9% (196/678) of the patients showed a moderate to severe degree (Grade III or IV) of osteoarthritis. In total, 1552 patients were registered, 155 reruptures (9.98%) and a total of 300 (19.3%) new surgeries, of which 228 meniscectomy (14.69%), 21 (1.35%) knee arthroplasty and 17 (1.09%) hardware removal were recorded.

Conclusions

ACL reconstruction appears to result in mild osteoarthritis in the long term in most of the patients and only less than 33.2% develop a moderate to severe degree of knee OA according to IKDC radiographic score. A slight degree of osteoarthritis appears to be present in ACLR knees compared with contralateral healthy knees.

Level of Evidence

Level IV.

Health-Related Quality of Life and Psychological Outcomes in Participants with Symptomatic and Non-Symptomatic Knees after ACL Reconstruction

Background

Individuals who sustain an ACL injury and undergo reconstruction (ACLR) are at risk for the development of osteoarthritis. Recent investigations have applied the Englund criteria to categorize people with a history of ACLR as someone with a symptomatic or asymptomatic knee.

Purpose/Hypothesis

The purpose of this study was to examine differences in health-related quality of life (HRQL) and psychological outcomes in people with a history of ACLR who were categorized as symptomatic or non-symptomatic by application of the Englund criteria. The authors' hypothesized participants classified as symptomatic would have lower HRQL, increased fear-avoidance beliefs, and decreased resilience compared to participants classified as non-symptomatic.

Study design

Cross-sectional, survey.

Methods

Participants at least one-year after ACLR were recruited for the study and completed the Tegner Activity Scale, the Brief Resilience Scale (BRS), the modified Disablement in the Physically Active Scale (mDPA), and the Fear-Avoidance Belief Questionnaire (FABQ) at one time-point. Descriptive statistics were summarized using median [interquartile range] and differences between groups were examined using separate Mann-Whitney U tests.

Results

Participants with symptomatic knees had a significantly higher BMI (24.8 [6.4]) than the non-symptomatic group (21.2 [4.3], p=0.013). Participants in the symptomatic group had worse HRQL on the physical subscale (12.5 [16.3] vs. 0.0 [2.5], p<0.001) and mental subscale (2.0 [1] vs. 0.0 [1], p=0.031), higher scores on the FABQ-Sport (14.5 [11] vs. 0.0 [6], p<0.001) and FABQ-Physical Activity (20 [24] vs. 1 [4], p<0.001) and less resilience (3.7[0.42] vs. 4.0 [0.83], p=0.028) compared to those participants in the non-symptomatic group. There were no differences in current physical activity (p=0.285) or change in physical activity (p=0.124) levels between the two groups.

Conclusions

This series of differences may represent a cascade of events that can continue to negatively impact health outcomes across the lifespan for individuals with a history of ACLR. Future research should consider longitudinal investigations of these outcomes after injury and throughout the post-surgical and post-rehabilitation timeframe.

Level of Evidence

Level 3b.

The Delaware-Oslo ACL Cohort treatment algorithm yields superior outcomes to usual care 9-12 years after anterior cruciate ligament reconstruction

PURPOSE

Patient-reported outcomes were compared between participants who followed the treatment algorithm of the Delaware-Oslo ACL Cohort, consisting of progressive preoperative and postoperative rehabilitation, patient education, clinical testing and shared decision-making about treatment choice, and those who followed usual care 9-12 years after anterior cruciate ligament reconstruction (ACLR).

METHODS

Participants with primary ACLR were included from the Norwegian arm of the Delaware-Oslo ACL Cohort and the Norwegian Knee Ligament Registry (usual care). The Knee Injury and Osteoarthritis Outcome Score (KOOS) subscale scores and the International Knee Documentation Committee-Subjective Knee Form (IKDC-SKF) scores were compared. KOOS scores for the usual care group were converted to IKDC-SKF scores with recently published validated crosswalk. The percentages of participants with scores above predefined thresholds for patient acceptable symptom state (PASS) were also calculated.

RESULTS

Eighty of 100 (80%) participants from the Delaware-Oslo ACL Cohort and 1588 of 3248 (49%) from the usual care group participated in the follow-up. Participants from the Delaware-Oslo ACL Cohort had higher KOOS subscale (p < 0.001) and IKDC-SKF scores (p < 0.001), and a higher percentage reached PASS (84%-96% vs. 62%-76%, p ≤ 0.002) for KOOS Pain, symptoms, activities of daily living and sports compared to the usual care group. No significant differences were found for KOOS quality of life scores (not significant [n.s.]) or PASS percentages (80% vs. 74%, n.s.).

CONCLUSION

Participants with ACLR who followed the Delaware-Oslo ACL Cohort treatment algorithm had reduced knee symptoms, superior function and higher percentages of satisfactory outcomes than participants who followed usual care.

LEVEL OF EVIDENCE

Level II.

Ten-year outcomes of anterior cruciate ligament reconstruction with hamstring tendon autograft and femoral fixation with a cortico-cancellous screw suspension device

PURPOSE

To evaluate the clinical and radiographic outcomes of anterior cruciate (ACL) reconstruction at minimum 10-year follow-up.

METHODS

Ninety-three patients who underwent primary unilateral ACL reconstruction with hamstring tendon autograft, transtibial technique and femoral cortico-cancellous screw suspension device (Athrax, Leader Medica s.r.l) between 2010 and 2012 were retrospectively reviewed. Mean follow-up was 136 months. Evaluation was performed using the International Knee Documentation Committee score (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Score and Tegner Activity Level Scale. Incidence of OA was determined by comparing standard anteroposterior and lateral weightbearing radiographs of the ACL-reconstructed and contralateral knee. Osteoarthritis severity was graded according to the Kellgren-Lawrence (KL) score.

RESULTS

Median Tegner activity level was 6 (5-7). Lysholm and IKDC scores were 100 (95-100) and 90 (86-95), respectively, KOOS was 98 (95-100). Of ACL-reconstructed knees, 41 (50%) had radiographic OA, of which 6 (7.3%) had severe OA (KL III). Of the contralateral healthy knees, 28 (34.1%) had radiographic evidence of OA. Of these 22 (26.8%) and 6 (7.3%) patients had, respectively, KL-I and KL-II. 11 patients (11.8%) underwent subsequent knee surgery: 5 (5.4%) revisions, 3 (3.2%) meniscal surgeries, 2 (2.2%) other surgeries, 1 (1.1%) contralateral ACL reconstruction.

CONCLUSIONS

The study demonstrates that ACL reconstruction with HT autograft and cortico-cancellous screw suspension device determines satisfying clinical results after 10 years of follow-up. From our cohort, a low rate of graft failure has been reported, even though almost 50% of patients present a knee OA greater or equal to grade II KL.

Anatomic Double-Bundle and Single-Bundle Reconstructions Yield Similar Outcomes Following Anterior Cruciate Ligament Rupture: A Systematic Review and Meta-analysis

PURPOSE

To evaluate outcomes of arthroscopic single-bundle (SB) versus anatomic double-bundle (ADB) anterior cruciate ligament reconstruction (ACLR) in adults through a synthesis of randomized controlled trials (RCTs). We hypothesized that SB and ADB methods would lead to similar outcomes after reconstruction of ACL rupture.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist guided our reporting. To identify RCTs that compared SB and ADB reconstructions, a thorough literature search was conducted of PubMed, Embase, Cochrane library, and Web of Science. The methodologic quality of each included study was independently assessed by 2 authors using the Cochrane Collaboration's risk of bias tool. The Anatomic ACL Reconstruction Scoring Checklist (AARSC) was used to screen the eligibility of each study's operative approaches. Twelve clinical outcomes were investigated through pooled analyses conducted using Review Manager 5.3.

RESULTS

This meta-analysis synthesized 13 RCTs comparing postoperative outcomes between ADB and SB reconstructions of ACLs. After a minimum follow-up of 12 months, ADB and SB technique resulted in similar subjective clinical outcomes, including the International Knee Documentation Committee subjective score, Lysholm score, Tegner activity score, and Knee injury and Osteoarthritis Outcome Score sports subscale. Similarly, no statistically significant outcomes were found for objective outcomes such as International Knee Documentation Committee objective grade, pivot-shift test, Lachman test, side-to-side difference, extension deficit, flexion deficit, and osteoarthritis change. However, patients who underwent SB reconstruction had significantly greater complication rates than those that underwent ADB reconstruction.

CONCLUSIONS

When an ACLR approach meets a minimal total AARSC score of 8, ADB and SB techniques may result in similar subjective and objective outcomes, but the ADB technique may lead to lower complication rates following surgery. We recommend that surgeons favor ADB ACLR, as guided by the AARSC.

LEVEL OF EVIDENCE

Level I, systematic review and meta-analysis of Level I randomized controlled trials.

Cost-effectiveness analysis of a pragmatic randomized trial evaluating surgical reconstruction versus rehabilitation in patients with long-standing anterior cruciate ligament injury

Aims

The aim of this study was to estimate the incremental use of resources, costs, and quality of life outcomes associated with surgical reconstruction compared to rehabilitation for long-standing anterior cruciate ligament (ACL) injury in the NHS, and to estimate its cost-effectiveness.

Methods

A total of 316 patients were recruited and randomly assigned to either surgical reconstruction or rehabilitation (physiotherapy but with subsequent reconstruction permitted if instability persisted after treatment). Healthcare resource use and health-related quality of life data (EuroQol five-dimension five-level health questionnaire) were collected in the trial at six, 12, and 18 months using self-reported questionnaires and medical records. Using intention-to-treat analysis, differences in costs, and quality-adjusted life years (QALYs) between treatment arms were estimated adjusting for baseline differences and following multiple imputation of missing data. The incremental cost-effectiveness ratio (ICER) was estimated as the difference in costs divided by the difference in QALYs between reconstruction and rehabilitation.

Results

At 18 months, patients in the surgical reconstruction arm reported higher QALYs (0.052 (95% confidence interval (CI) -0.012 to 0.117); p = 0.177) and higher NHS costs (£1,017 (95% CI 557 to 1,476); p < 0.001) compared to rehabilitation. This resulted in an ICER of £19,346 per QALY with the probability of surgical reconstruction being cost-effective of 51% and 72% at a willingness-to-pay threshold of £20,000 and £30,000 per QALY, respectively.

Conclusion

Surgical reconstruction as a management strategy for patients with long-standing ACL injury is more effective, but more expensive, at 18 months compared to rehabilitation management. In the UK setting, surgical reconstruction is cost-effective.

Approximately half of pediatric or adolescent patients undergoing revision anterior cruciate ligament reconstruction return to the same level of sport or higher: A systematic review

PURPOSE

To summarise the surgical techniques and clinical outcomes in paediatric and adolescent patients undergoing revision anterior cruciate ligament reconstruction (r-ACLR).

METHODS

Three databases (MEDLINE, PubMed and EMBASE) were searched from inception to 29 July 2023. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, surgical details, patient-reported outcome measures (PROMs), rates of instability, rupture and return to sport (RTS) were extracted.

RESULTS

Eight studies comprising 706 (711 knees) patients were included (48.7% female). The mean age at r-ACLR was 17.1 years (range: 16.5-18.0). Autografts (67.5%) were more common than allografts (32.2%) in revision, with bone-patellar tendon-bone (BPTB) being the most prevalent autograft source (59.6%). Bone grafts were used in seven patients (4.8% of 146 patients). The most common femoral and tibial fixation techniques were interference screws (37.6% and 38.1%, of 244 patients, respectively). The most common tunnelling strategy was anatomic (69.1% of 236 patients), and meniscus repairs were performed in 39.7% of 256 patients. The re-rupture rate was 13.0% in 293 patients. RTS at the same level or higher was 51.6% in 219 patients. The mean (SD) Lysholm score was 88.1 (12.9) in 78 patients, the mean (SD) Tegner score was 6.0 (1.6) in 78 patients, and the mean (SD) IKDC score was 82.6 (16.0) in 126 patients.

CONCLUSION

R-ACLR in paediatric and adolescent patients predominantly uses BPTB autografts and interference screw femoral and tibial fixation with concomitant meniscal procedures. Rates of re-rupture and RTS at the same level or higher were 13.0% and 51.6%, respectively. Information from this review can provide orthopaedic surgeons with a comprehensive understanding of the most commonly used operative techniques and their outcomes for revision ACLR in this population.

LEVEL OF EVIDENCE

Level IV.

Evaluation of Graft Maturation by MRI in Anterior Cruciate Ligament Reconstruction With and Without Concomitant Anterolateral Ligament Reconstruction

Background

Single-bundle anterior cruciate ligament reconstruction (SB-ACLR) with concomitant anterolateral ligament reconstruction (ALLR) has been associated with better clinical results when compared with isolated SB-ACLR. However, it is not known whether the improved outcomes are the result of the influence of concomitant ALLR on ACL graft healing.

Purpose/Hypothesis

The purpose of this study was to determine whether concomitant ALLR is associated with improved graft ligamentization after SB-ACLR. It was hypothesized that ALLR would not affect graft healing.

Study Design

Cohort study; Level of evidence, 3.

Methods

A 1 to 1 matching study was conducted on a consecutive series of 732 patients who underwent ACLR using a hamstring tendon autograft between 2007 and 2019. Patients were excluded if they had skeletal immaturity, inflammatory joint disease, multiple ligament reconstruction (other than ALLR), or a graft rupture. Patients with concomitant SB-ACLR and ALLR (SB-ACLR/ALLR) and isolated SB-ACLR were matched 1 to 1 based on age, sex, examination under anesthesia (EUA) grade 3 pivot shift, EUA grade 3 anterior drawer test, presence of graft impingement, sagittal graft angle, skeletal maturity, lack of generalized ligamentous laxity, and multiple ligamentous injury. A total of 40 matched pairs underwent postoperative magnetic resonance imaging (MRI) within the second year after surgery to assess graft ligamentization, which was measured by the signal-to-noise quotient (SNQ) of the ACL graft.

Results

The mean follow-up period was 41 months, with a 2-year follow-up rate of 80% in the SB-ACLR/ALLR group and 98% in the isolated SB-ACLR group. The mean duration between the index operation and MRI was 16.4 ± 3.4 months. No significant difference was observed in the SNQ of the ACL graft between the SB-ACLR/ALLR and SB-ACLR groups (6.9 ± 4.6 vs 5.2 ± 4.8, respectively; P = .066).

Conclusion

Study findings indicated that a concomitant ALLR at the time of hamstring tendon autograft ACLR did not affect graft healing as assessed by the SNQ of the ACL graft.

Postoperative quadriceps weakness and male sex are risk factors for patellofemoral articular cartilage lesions after anatomical anterior cruciate ligament reconstruction

PURPOSE

Patellofemoral (PF) compartment cartilage lesions are a frequent problem after anterior cruciate ligament (ACL) reconstruction. This study aimed to determine the factors that influence PF cartilage lesions after anatomical ACL reconstruction.

METHODS

This study enrolled a total of 114 patients who did not manifest PF compartment cartilage lesions during anatomical ACL reconstruction and underwent second-look arthroscopy 18 months postoperatively. Arthroscopy using the International Cartilage Repair Society (ICRS) classification was used to assess cartilage lesions. The correlation between surgical findings, radiographic factors, and clinical factors and change of ICRS grade was analysed. Multivariate regression analysis was conducted to reveal the independent risk factors for PF cartilage lesions among patients' demographic data and parameters that correlated with the change of ICRS grade in the correlation analyses.

RESULTS

ICRS grade changes in PF cartilage were significantly correlated with age, sex, quadriceps strength at 1 year postoperatively, hamstrings strength at pre- and 1 year postoperatively, and single leg hop test at 1 year postoperatively. However, no significant correlation was found between the time between injury and surgery, posterior tibial slope angle, pre- and postoperative Tegner activity scale, graft type, initial graft tension, meniscus injury, meniscus injury treatment, pre- and postoperative range of motion, anteroposterior laxity and preoperative quadriceps strength, and the change in ICRS grade. Multivariate regression analysis revealed male (P = 0.019) and quadriceps strength weakness at 1 year postoperatively (P = 0.009) as independent risk factors for PF cartilage lesions.

CONCLUSIONS

Quadriceps strength weakness 1 year after ACL reconstruction and males were correlated with a new PF cartilage lesion after anatomical ACL reconstruction, with no significant correlation between bone-patellar tendon-bone autograft, initial graft tension, or extension deficit and new PF cartilage lesion. Rehabilitation that focuses on quadriceps strength after ACL reconstruction is recommended to prevent new PF cartilage lesions.

LEVEL OF EVIDENCE

Level IV.

Anterior cruciate ligament femoral footprint is oblong-ovate, triangular, or two-tears shaped in healthy young adults: three-dimensional MRI analysis

PURPOSE

This study aimed to evaluate the morphology of the anterior cruciate ligament (ACL) femoral footprint with three-dimensional magnetic resonance imaging (3D MRI) in healthy knees.

METHODS

Fifty subjects with healthy knees were recruited, utilising 3D-SPACE sequences for ACL evaluation. The ACL was manually segmented, and the shape, size and location of the ACL femoral footprint were evaluated on a reformatted oblique-sagittal plane, which aligned closely with the ACL attachment. Statistical analysis included one-way ANOVA for continuous variables and Fisher's exact test for categorical variables, with a P value < 0.05 considered significant.

RESULTS

Three types of ACL femoral footprint shape were identified, namely, oblong-ovate (OO) in 33 knees (66%), triangular (Tr) in 12 knees (24%) and two-tears (TT) in 5 knees (10%), with the mean areas being 58, 47 and 68 mm2, respectively. Within group TT, regions with similar sizes but different locations were identified: high tear (TT-H) and low tear (TT-L). Notably, group OO demonstrated a larger notch height index, whilst group TT was characterised by a larger α angle and lateral femoral condyle index. A noticeable variation was observed in the location of the femoral footprint centre across groups, with group TT-L and group Tr showing a more distal position relative to the apex of the deep cartilage. According to the Bernard and Hertel (BH) grid, the ACL femoral footprint centres in group TT-L exhibited a shallower and higher position than other groups. Furthermore, compared to group OO and TT-H, group Tr showed a significantly higher position according to the BH grid.

CONCLUSION

In this study, the morphology of the ACL femoral footprint in healthy young adults was accurately evaluated using 3D MRI, revealing three distinct shapes: OO, Tr and TT. The different ACL femoral footprint types showed similar areas but markedly different locations. These findings emphasise the necessity of considering both the shape and precise location of the ACL femoral footprint during clinical assessments, which might help surgeons enhance patient-specific surgical plans before ACL reconstruction.

LEVEL OF EVIDENCE

IV.

The Risk Factors and Preventive Strategies of Poor Knee Functions and Osteoarthritis after Anterior Cruciate Ligament Reconstruction: A Narrative Review

Anterior cruciate ligament reconstruction (ACLR) is the standard surgical treatment for ACL injury, which typically uses a graft to replace the torn ligament in the knee that uses small incisions with minimally invasive surgery. The optimal knee functions following ACLR depend on rehabilitation processes before and after the surgery. Knee function is the ability of the knee to perform various types of functional movements like walking, squatting, running, jumping, and pivoting where patients expect to achieve maximum knee function or at least more than 80% of its initial condition before the injury to avoid being categorized as poor knee function after ACLR. Patients use patient-reported outcome measures to collect data on their health status and quality of life after ACLR. Post-traumatic osteoarthritis (PTOA) is a type of OA that manifests in local cartilage injury caused by chondrocyte death, and matrix dispersion occurs following a joint injury like ACL injury. Gender, time from injury to surgery, and graft type were considered as risk factors for poor knee function after ACLR, while overweight, meniscus tear, and cartilage defect as risk factors for PTOA. However, age is an internal risk factor for both poor knee function and PTOA following ACLR. This review suggests several strategies to prevent both conditions, including a pre-operative program, comprehensive rehabilitation, body weight control, and return to sport (RTS) consideration based on physical capacity, proper time, and psychological readiness.

Physical inactivity 5-8 years after anterior cruciate ligament reconstruction is associated with knee-related self-efficacy and psychological readiness to return to sport

Objectives

To investigate whether patient demographics and patient-reported outcomes (PROs), respectively, are associated with physical inactivity (PI) 5-8 years after primary anterior cruciate ligament reconstruction (ACLR).

Methods

This case control observational study included individuals who had undergone primary ACLR between the ages of 15 and 65 years and had responded to PROs 18 months postoperatively. These individuals were asked to answer a questionnaire regarding their present level of physical activity (PA) at 5-8 years after ACLR. Patient-demographic data and results from the Knee injury and Osteoarthritis Outcome Score, the Knee Self-Efficacy Scale and the ACL Return to Sport (RTS) after Injury scale from 18 months after ACLR were extracted from a rehabilitation-specific register. Univariable logistic regression analyses were performed with PI (<150 min PA per week/≥150 min PA/week) as the dependent variable.

Results

Of 292 eligible participants, 173 (47% women; mean±SD age = 31±11 years) responded to the PA questionnaire. In all, 14% (n=25; 28% women) were classified as physically inactive. Participants with lower levels of present and future self-efficacy, OR 1.35 (CI 1.05 to 1.72) and OR 1.20 (CI 1.12 to 1.45), and lower levels of psychological readiness to RTS, OR 1.19 (CI 1 to 1.43), at the 18-month follow-up, had higher odds of being physically inactive 5-8 years after ACLR. None of the patient demographic variables was able to predict PI.

Conclusion

Lower levels of knee-related self-efficacy and psychological readiness to RTS, 18 months after ACLR, were associated with PI 5-8 years after surgery.

Previous anterior cruciate ligament reconstruction influences the complication rate of total knee arthroplasty: a systematic review and meta-analysis

Purpose

The results of total knee arthroplasty (TKA) following anterior cruciate ligament (ACL) reconstruction are still under-investigated. The purpose of this research is to investigate the differences between TKA after ACL reconstruction and TKA for primary osteoarthritis through a review and meta-analysis of the literature.

Methods

Case-control and cohort studies reporting outcomes of TKA following ACL reconstruction were considered eligible for inclusion. The primary endpoint was to systematically review and meta-analyze the reported complications of TKA following ACL reconstruction. The outcomes have been compared with a group of patients who underwent TKA for primary knee osteoarthritis (OA) with any previous ACL surgery. Secondary endpoints were to assess and compare technical difficulties and results including the operative time, the use of revision components, the request for intraoperative release or additional procedures, the revision rate, and the clinical outcomes.

Results

Seven studies were included involving 1645 participants, 619 of whom underwent TKA in previous ACL reconstruction and 1026 TKA for primary OA with no previous ACL reconstruction. Meta-analysis showed that TKA in previous ACL reconstruction had a significantly higher complication rate (OR = 2.15, P < 0.001), longer operative times (mean differences (MD): 11.19 min; P < 0.001) and increased use of revision components (OR = 2.16; P < 0.001) when compared to the control group without differences of infection, and revision rate.

Conclusions

TKA in a previous ACL reconstruction has a significantly higher complication rate, longer operative times, and a higher need for revision components and intraoperative soft tissue releases in comparison to TKA for primary OA without previous ACL reconstruction.

Post-traumatic osteoarthritis: the worst associated injuries and differences in patients' profile when compared with primary osteoarthritis

BACKGROUND

The estimated prevalence of post-traumatic osteoarthritis (PTOA) is 10-12% and in this study 12.4%. Different knee and hip injuries have been identified as risk factors for PTOA, but there is no consensus regarding the most painful and disabling injuries. Identifying these injuries might help in the prevention of PTOA. Additionally, patients with PTOA have a higher risk for complications after arthroplasty than patients with primary OA, perhaps due to differences in the profile and comorbidity that might help to explain the difference. This work aims 1) to identify the most common past injuries associated with the most painful and disabling PTOA cases in non-athlete patients and 2) to compare the comorbidities and characteristics between PTOA and primary OA.

METHODS

Retrospective hospital-based cohort study with 1290 participants with joint complaints or who received arthroplasty. Medical records included demographic information, diagnosis, medication, smoking, alcohol history and comorbidities. Data from January 2012 orthopaedic consults till December 2019 was reviewed and had the type and date of injury, pain score by the numerical rating scale and walking disability. Odds Ratio (OR) and 95% confidence intervals are presented.

RESULTS

There were 641 cases with primary OA (65% females) and 104 with PTOA (61% males). Patients with PTOA were 7.5 years younger (P < 0.001), reported more alcohol consumption (P = 0.01) and had higher odds of osteoporotic fractures (OP) and psychosis than patients with primary OA (OR = 2.0, CI = 1.06-3.78 and OR = 2.90, CI = -0.91-9.18, respectively). Knee fractures were most common in males and hip fractures in females (31% and 37.5%, respectively, P < 0.005). The PTOA-associated injuries with the highest pain and disability scores were meniscal injuries and hip fractures. Besides, in the group with primary OA, there were more diabetes, hypertension and hypothyroidism cases than in PTOA. However, after adjustment, differences were only significant for diabetes (OR_adj = 1.78, CI = 1.0-3.2).

CONCLUSIONS

Past meniscal injuries and hip fractures were the most relevant PTOA-associated injuries regarding pain and walking disability. This, together with differences in their profile when compared with primary OA, might help to decide the orthopaedic management of these injuries to prevent complications such as PTOA and recurrence, with appropriate preoperative planning, surgery choice and comorbidity treatment.

Knee valgus and patellofemoral instability after pediatric anterior cruciate ligament reconstruction: a case report and review of the literature

BACKGROUND

Pediatric athletes who undergo anterior cruciate ligament reconstruction are at risk for a growth deformity if the surgery violates the physes.

CASE

A 12-year-old African American boy underwent anterior cruciate ligament reconstruction using a hamstring autograft. The procedure violated the distal femoral growth plate and the perichondrial ring of LaCroix, resulting in a distal femoral lateral physeal growth arrest. Three years later, he had developed a 15° valgus deformity, an increased quadriceps angle and patellofemoral instability. He was able to return to sports after undergoing a distal femoral osteotomy to correct the valgus and medial patellofemoral ligament reconstruction to stabilize the patella.

CONCLUSION

Anterior cruciate ligament reconstruction in athletes with open physes has the potential to cause distal femoral valgus deformity, an increased quadriceps angle, and subsequent patellofemoral instability.

Anterior cruciate ligament failure and management

Anterior cruciate ligament (ACL) reconstruction failure can be defined as abnormal knee function due to graft insufficiency with abnormal laxity or failure to recreate a functional knee according to the expected outcome. Traumatic ruptures have been reported as the most common reason for failure. They are followed by technical errors, missed concomitant knee injuries, and biological failures. An in-depth preoperative examination that includes a medical history, clinical examinations, advanced imaging, and other appropriate methods is of utmost importance. There is still no consensus as to the ideal graft, but autografts are the favorite choice even in ACL revision. Concomitant meniscal treatment, ligamentous reconstruction, and osteotomies can be performed in the same surgical session to remove anatomical or biomechanical risk factors for the failure. Patient expectations should be managed since outcomes after ACL revision are not as good as those following primary ACL reconstruction.

Preoperative ultrasound can accurately predict the diameter of double-stranded peroneus longus tendon autografts

PURPOSE

This study aimed to determine the correlation between the intraoperative diameter of double-stranded peroneus longus tendon (2PLT) and length of the PLT autograft and preoperative ultrasound (US) measurements, as well as radiographic and anthropometric measurements. The hypothesis was that US can accurately predict the diameter of 2PLT autografts during operation.

METHODS

Twenty-six patients underwent ligament reconstruction with 2PLT autografts were included. Preoperative US was used to calculate the in situ PLT cross-sectional area (CSA) at seven levels (0, 1, 2, 3, 4, 5, 10 cm proximal to the harvest start point). Femoral width, notch width, notch height, maximum patellar length, and patellar tendon length were determined on preoperative radiographs. Intraoperative measurements of PLT were made, including all fiber lengths of PLT and diameters of 2PLT using sizing tubes calibrated to 0.5 mm.

RESULTS

CSA at 1 cm proximal to the harvest site had the highest correlation with the diameter of 2PLT (r = 0.84, P < 0.001). Calf length had the highest correlation with PLT length (r = 0.65, P < 0.001). The diameter of the 2PLT autografts could be predicted by the following formula: 4.6 + 0.2 × [sonographic CSA of PLT at 1 cm level]; the length of PLT could be predicted by the following formula: 5.6 + 0.5 × Calf length.

CONCLUSION

The diameter of 2PLT and length of PLT autografts can be accurately predicted by preoperative US and calf length measurements, respectively. Accurate preoperative prediction of the diameter and length of autologous grafts can provide the most suitable and individualized graft for patients.

LEVEL OF EVIDENCE

IV.

Are Neighborhood Conditions Associated With Surgical Delays and Meniscus Tears in Children and Adolescents Undergoing ACL Reconstruction?

BACKGROUND

Markers of a patient's social determinants of health, including healthcare insurance and median household income based on ZIP Code, have been associated with the interval between injury and ACL reconstruction (ACLR) as well as the presence of concomitant meniscus tears in children and adolescents. However, the aforementioned surrogate indicators of a patient's social determinants of health may not reflect all socioeconomic and healthcare resources affecting the care of ACL injuries in children and adolescents. The use of multivariate indices such as the Child Opportunity Index (COI) may help to better identify patients at risk for increased risk for delay between ACL injury and surgery, as well as the incidence of meniscus tears at the time of surgery. The COI is a summative measure of 29 indicators that reflect neighborhood opportunities across three domains: education, health and environment, and social and economic factors. COI scores range from 0 to 100 (100 being the highest possible score), as well as five categorical scores (very low, low, moderate, high, and very high) based on quintile rankings.

QUESTIONS/PURPOSES

To investigate the relationship between neighborhood conditions and the treatment of ACL injuries in children and adolescents via the COI, we asked: (1) Is a lower COI score associated with a longer delay between ACL injury and surgery? (2) Does a higher proportion of patients with lower COI scores have meniscus tears at the time of ACLR?

METHODS

In this retrospective, comparative study, we considered data from 565 patients, 18 years or younger, who underwent primary ACLR at an urban, tertiary children's hospital between 2011 and 2021. Of these patients, 5% (31 of 565) did not have a clearly documented date of injury, 2% (11 of 565) underwent revision reconstructions, and 1% (5 of 565) underwent intentionally delayed or staged procedures. Because we specifically sought to compare patients who had low or very low COI scores (lowest two quintiles) with those who had high or very high scores (highest two quintiles), we excluded 18% (103 of 565) of patients with moderate scores. Ultimately, 73% (415 of 565) of patients with COI scores in either the top or bottom two quintiles were included. Patient addresses at the time of surgery were used to determine the COI score. There were no differences between the groups in terms of gender. However, patients with high or very high COI scores had a lower median (IQR) age (15 years [2.6] versus 17 years [1.8]; p < 0.001) and BMI (23 kg/m 2 [6.1] versus 25 kg/m 2 [8.8]; p < 0.001), were more commonly privately insured (62% [117 of 188] versus 22% [51 of 227]; p < 0.001), and had a higher proportion of patients identifying as White (67% [126 of 188] versus 6.2% [14 of 227]; p < 0.001) compared with patients with low or very low COI scores. Medical records were reviewed for demographic, preoperative, and intraoperative data. Univariate analyses focused on the relationship of the COI and interval between injury and surgery, frequency of concomitant meniscus tears, and frequency of irreparable meniscus tears treated with partial meniscectomy. Multivariable regression analyses were used to determine factors that were independently associated with delayed surgery (longer than 60 and 90 days after injury), presence of concomitant meniscal injuries, and performance of meniscectomy. Multivariable models included insurance and race or ethnicity to determine whether COI was independently associative after accounting for these variables.

RESULTS

Patients with a high or very high COI score had surgery earlier than those with a low or very low COI score (median [IQR] 53 days [53] versus 97 days [104]; p < 0.001). After adjusting for insurance and race/ethnicity, we found that patients with a low or very low COI score were more likely than patients with a high or very high COI score to have surgery more than 60 days after injury (OR 2.1 [95% CI 1.1 to 4.0]; p = 0.02) or more than 90 days after injury (OR 1.8 [95% CI 1.1 to 3.4]; p = 0.04). Furthermore, patients with low or very low COI scores were more likely to have concomitant meniscus tears (OR 1.6 [95% CI 1.1 to 2.5]; p = 0.04) compared with patients with high or very high COI scores. After controlling for insurance, race/ethnicity, time to surgery, and other variables, there was no association between COI and meniscectomy (OR 1.6 [95% CI 0.9 to 2.8]; p = 0.12) or presence of a chondral injury (OR 1.7 [95% CI 0.7 to 3.9]; p = 0.20).

CONCLUSION

As the COI score is independently associated with a delay between ACL injury and surgery as well as the incidence of meniscus tears at the time of surgery, this score can be useful in identifying patients and communities at risk for disparate care after ACL injury. The COI score or similar metrics can be incorporated into medical records to identify at-risk patients and dedicate appropriate resources for efficient care. Additionally, neighborhoods with a low COI score may benefit from improvements in the availability of additional and/or improved resources. Future studies should focus on the relationship between the COI score and long-term patient-reported functional outcomes after ACL injury, identification of the specific timepoints in care that lead to delayed surgery for those with lower COI scores, and the impact of community-based interventions in improving health equity in children with ACL injury.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Is Preferred Language Other Than English Associated With Delayed Surgery After ACL Injury in Children and Adolescents?

BACKGROUND

Previous studies have investigated the impact of social determinants of health, such as the type of healthcare insurance and household income, on children and adolescents with ACL tears. However, despite the increasing incidence of ACL injury in young patients and a substantial proportion of families who may prefer languages other than English, the relationship between language and clinical care remains unclear.

QUESTIONS/PURPOSES

To investigate the relationship between language and the care of children and adolescents with ACL tears, we asked: (1) Is a preferred language other than English (PLOE) associated with a delay between ACL injury and surgery? (2) Is a PLOE associated with a greater odds of a patient experiencing a meniscal tear and undergoing a meniscectomy than in those who prefer English?

METHODS

We treated 591 patients surgically for ACL injuries between 2011 and 2021. Of those, we considered patients aged 18 years or younger who underwent primary ACL reconstruction for this retrospective, comparative study. Five percent (31 of 591) of patients were excluded because the date of injury was not clearly documented, 2% (11 of 591) were revision reconstructions, and 1% (6 of 591) underwent procedures that were intentionally delayed or staged, leaving 92% (543 of 591) for analysis. The mean age was 16 ± 2 years, and 51% (276 of 543) of patients were boys. The family's preferred language was noted, as were demographic data, time between injury and surgery, and intraoperative findings. A language other than English was preferred by 21% (113 of 543) of patients. Of these, 94% (106 of 113) preferred Spanish. In a univariate analysis, we used independent-samples t-tests, Mann-Whitney U-tests, and Fisher exact tests, as appropriate. Purposeful-entry multivariable regression analyses were used to determine whether PLOE was associated with increased time to surgery, concomitant meniscus injury, or performance of meniscectomy while adjusting for confounding variables. Variables were included in multivariable models if they met the threshold for statistical significance in univariate testing (p < 0.05).

RESULTS

The median time between injury and ACL reconstruction was shorter in families who preferred English compared with those with a PLOE (69 days [IQR 80] versus 103 days [IQR 107)]; p < 0.001). After controlling for potentially confounding variables like insurance and age, we found that patients whose families had a PLOE had greater odds of undergoing surgery more than 60 days after injury (OR 2.2 [95% CI 1.3 to 3.8]; p = 0.005) and more than 90 days after injury (OR 1.8 [95% CI 1.1 to 2.8]; p = 0.02). After controlling for insurance, age, and other factors, PLOE was not associated with surgical delay beyond 180 days, concomitant meniscal tears, or performance of meniscectomy.

CONCLUSION

In this study of children and adolescents undergoing primary ACL reconstruction, patients whose families prefer a language other than English experienced a longer delay between injury and surgery. In areas with a large proportion of families with a PLOE, partnerships with primary care clinicians, emergency departments, schools, athletic teams, and community organizations may improve efficiency in the care of children with ACL injuries. Clinicians proficient in other languages, reliable interpreter services, and translated references and resources may also be impactful. Our results suggest a need for further research on the experiences, needs, and long-term outcomes of these patients, as well as the association of preferred language with results after surgery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Patients that maintain their pre-injury level of physical activity 3-5 years after ACL reconstruction are, 18 months after surgery, characterised by higher levels of readiness to return to sport

PURPOSE

To characterise patients who had returned to their pre-injury physical activity (PA) or higher at 18 months and maintained that level of PA 3-5 years after the primary ACL reconstruction and to describe the level, frequency, and type of PA participation during the first 5 years after ACL reconstruction  METHOD: Data, from follow-ups at 18 months and 3-5 years after an ACL reconstruction, were extracted from a rehabilitation-specific register. Patients, 15-65 years of age, were included. The data comprised patient-reported outcomes and the results from two questions with respect to the level, frequency, and type of PA. Comparisons were made between patients who had and had not maintained their pre-injury level of PA at the follow-up 3-5 years after an ACL reconstruction.

RESULTS

A total of 272 patients met the inclusion criteria. The mean follow-up time was 3.8 years (min-max: 2.9-5.1) after the ACL reconstruction. Of patients who had returned to their pre-injury or a higher level of PA at the 18 month follow-up (n = 114), 68% (n = 78) maintained that level at the 3- to 5-year follow-up after ACL reconstruction. These patients reported a higher level of psychological readiness to return to sport (98 versus 79; p = 0.013). Moreover, these patients were 6.0 years older (p = 0.016) and were characterised by male sex (56% versus 44%; p = 0.028) and a lower level of pre-injury PA (p = 0.013). At the follow-up 3-5 years after the ACL reconstruction, more than 90% met the recommendations for PA. However, the prevalence of physical inactivity had increased and the involvement in organised PA had decreased compared with the 18-month follow-up.

CONCLUSIONS

Two out of three patients who have returned to their previous level of PA at 18 months can be expected to maintain that level, 3-5 years following ACL reconstruction. These patients were mainly characterised by a higher level of psychological readiness, especially in patients who participated in knee-strenuous sport and were younger than 20 years of age. The results of this study suggest that patients become more physically inactive over time, implicating the importance of clinicians helping patients find a suitable PA that may help patients maintain an active lifestyle.

Evaluating the risk of knee osteoarthritis following unilateral ACL reconstruction based on an EMG-assisted method

Objective: Anterior cruciate ligament reconstruction (ACLR) cannot decrease the risk of knee osteoarthritis after anterior cruciate ligament rupture, and tibial contact force is associated with the development of knee osteoarthritis. The purpose of this study was to compare the difference in bilateral tibial contact force for patients with unilateral ACLR during walking and jogging based on an EMG-assisted method in order to evaluate the risk of knee osteoarthritis following unilateral ACLR. Methods: Seven unilateral ACLR patients participated in experiments. The 14-camera motion capture system, 3-Dimension force plate, and wireless EMG test system were used to collect the participants' kinematics, kinetics, and EMG data during walking and jogging. A personalized neuromusculoskeletal model was established by combining scaling and calibration optimization. The inverse kinematics and inverse dynamics algorithms were used to calculate the joint angle and joint net moment. The EMG-assisted model was used to calculate the muscle force. On this basis, the contact force of the knee joint was analyzed, and the tibial contact force was obtained. The paired sample t-test was used to analyze the difference between the participants' healthy and surgical sides of the participants. Results: During jogging, the peak tibial compression force on the healthy side was higher than on the surgical side (p = 0.039). At the peak moment of tibial compression force, the muscle force of the rectus femoris (p = 0.035) and vastus medialis (p = 0.036) on the healthy side was significantly higher than that on the surgical side; the knee flexion (p = 0.042) and ankle dorsiflexion (p = 0.046) angle on the healthy side was higher than that on the surgical side. There was no significant difference in the first (p = 0.122) and second (p = 0.445) peak tibial compression forces during walking between the healthy and surgical sides. Conclusion: Patients with unilateral ACLR showed smaller tibial compression force on the surgical side than on the healthy side during jogging. The main reason for this may be the insufficient exertion of the rectus femoris and vastus medialis.

Different patient and activity-related characteristics result in different injury profiles for patients with anterior cruciate ligament and posterior cruciate ligament injuries

PURPOSE

To compare patient characteristics including patient sex, age, body mass index (BMI), activities at the time of injury and injury profiles in patients with anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries.

METHODS

Data were obtained from the Swedish National Knee Ligament Registry. Two study groups were created: (1) index ACL reconstruction (ACL group) and (2) index PCL reconstruction (PCL group). Between-group differences were investigated using Fisher's exact test and Fisher's non-parametric permutation test for dichotomous variables and continuous variables, respectively.

RESULTS

Of 39,010 patients, 38,904 were ACL injuries. A larger proportion of patients with combined injuries to the PCL, meniscus and cartilage were female, aged > 25 years and with a BMI of > 35 kg/m² compared with patients with combined injuries to the ACL, meniscus and cartilage. An isolated ACL injury was more commonly found in males, while all other injury profiles of ACL, including combined injuries with meniscus, cartilage and collateral ligament injuries, were more frequently observed in females. The PCL injuries were sustained either during pivoting sports, non-pivoting sports or were traffic-related.

CONCLUSION

Different patient characteristics (BMI, age and sex), and activities at the time of injury (sport- versus traffic-related activities), resulted in distinct injury profiles for the ACL and PCL groups. These findings provide valuable information of the way specific injury patterns of cruciate ligament injuries occur, and subsequently may help clinicians with the diagnostic process of ACL and PCL injuries.

LEVEL OF EVIDENCE

III.

An eponymous history of the anterolateral ligament complex of the knee

BACKGROUND

Recent interest has surged in the anterolateral ligament (ALL) and complex (ALC) of the knee. Its existence and role in rotary stability of the knee, particularly in the setting of anterior cruciate ligament (ACL) reconstruction, remains a contentious and controversial topic.

UNDERSTANDING THE ALC

We must review our history and recognize the pioneers who pushed our understanding of the ALL forward before it was popularly recognized as a discrete structure. Additionally, given that many eponyms remain in common use related to the ALC, we must standardize our nomenclature to prevent misuse or misunderstanding of terms in the literature. In this review, modern understanding of the anterolateral ligament complex (ALC) is traced to 1829 by exploring eponymous terms first in anatomy and then in surgical technique. Understanding our history and terminology will allow us to better understand the ALC itself.

CONCLUSION

This review aims to provide historical context, define terminology, and provide insight into the clinical relevance of the ALC.

Correlation of Lower Limb Muscle Activity with Knee Joint Kinematics and Kinetics during Badminton Landing Tasks

A study on a single-leg landing task after an overhead stroke in badminton suggests that poor knee biomechanical indicators may be a risk factor for anterior cruciate ligament (ACL) injury. A preventive program targeting neuromuscular control strategies is said to alter the biomechanics of the knee joint and have a beneficial effect on reducing ACL injury. However, the relationship between muscle activity around the knee joint and knee biomechanical risk factors in the badminton landing task is unclear. The purpose of this study was to investigate the relationship between this movement pattern of muscle activity and knee kinematics and kinetics. This experiment analyzed knee muscle activity and biomechanical information in a sample of 34 badminton players (17 male, 17 female) during a badminton landing task. We assessed the relationship between the rectus femoris (RF), medial hamstring (MHAM), lateral hamstring (LHAM), medial gastrocnemius (MGAS), lateral gastrocnemius (LGAS), medial and lateral hamstring to quadriceps co-contraction ratio (MH/Q and LH/Q) with the knee flexion angle, valgus angle, extension moment, valgus moment, and proximal tibial anterior shear force. A moderate negative correlation was found between the peak knee flexion angle and electromyography (EMG) activity in LGAS (r = 0.47, p = 0.0046, R² = 0.23, 95% CI: 0.16 to 0.70). Peak proximal tibial shear force showed strong and positive correlations with RF EMG activity (r = 0.52, p = 0.0016, R² = 0.27, 95% CI: 0.22 to 0.73) and strong and negative correlations with MH/Q (r = 0.50, p = 0.0023, R² = 0.25, 95% CI: 0.20 to 0.72). The knee extension moment showed moderate and positive correlations with RF EMG activity (r = 0.48, p = 0.0042, R² = 0.23, 95% CI: 0.17 to 0.70) and strong and negative correlations with MH/Q (r = 0.57, p = 0.0004, R² = 0.33, 95% CI: 0.29 to 0.76). The peak knee valgus moment showed strong and positive correlations with LH/Q (r = 0.55, p = 0.0007, R² = 0.31, 95% CI: 0.26 to 0.75). Our findings suggest that there is a correlation between lower extremity muscle activity and knee kinematics and kinetics during the single-leg landing task in badminton; therefore, lower extremity muscle activity should be considered when developing rehabilitation or injury prevention programs.

The coronal lateral collateral ligament sign in the anterior cruciate ligament-injured knees was observed regardless of the knee laxity based on the quantitative measurements

PURPOSE

The coronal lateral collateral ligament (LCL) sign has been reported to be associated with deviated position of the tibia on MRI due to anterior cruciate ligament (ACL) injuries. However, the relationships between LCL sign and clinical knee laxity evaluations are still unclear. The purpose of the study was to investigate the relationship between the coronal LCL sign and knee laxity measurements.

METHODS

A retrospective review of unilateral ACL injured patients who underwent ACL reconstruction was performed. The coronal LCL sign was determined using magnetic resonance imaging (MRI). Clinical grading of the pivot-shift test, KT-1000 measurements, and quantitative measurements of the Lachman test and the pivot-shift test using an electromagnetic system, were compared between patients with positive and negative coronal LCL sign. A subgroup analysis of different age groups was then performed, dividing patients to adolescent (age ≤ 18 years) and adult (age > 18 years) groups.

RESULTS

A total of 85 patients were enrolled, of which 45 patients had coronal LCL signs. The coronal LCL sign was not associated with the pivot-shift test clinical grading (n.s), KT-1000 measurement (n.s), the tibial translation during the Lachman test (n.s), or with tibia acceleration (n.s) and translation (n.s) during the pivot-shift test. The subgroup analysis also showed that the aforementioned parameters were not associated with the coronal LCL sign in either adolescent or adult subgroups.

CONCLUSION

The occurrence of coronal LCL sign in MRI did not imply greater clinical knee laxity evaluations in patients with ACL tears. The knee laxity should routinely be evaluated regardless the coronal LCL sign.

LEVEL OF EVIDENCE

Level III.

Osteoarthritis Progression after ACL Reconstruction Was Significantly Higher Than That of the Healthy Contralateral Knees: Long-Term Follow Up Study of Mean 16.4 Years

Background: This study aimed to assess long-term progression of osteoarthritis (OA) after isolated anterior cruciate ligament (ACL) reconstruction in athletes compared to the healthy contralateral side. Methods: The study included 15 patients and 30 knees with a mean age of 40 years (range, 35–46) years, none of whom had had revision surgery or an injury to the contralateral side. The mean follow-up period was 16.4 years (range, 13–22). Clinical and radiographic assessment included the Tegner activity scale (TAS), International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Kellgren and Lawrence (KL) grade. The long-term results of the injured knees were compared with the status of the healthy contralateral side and compared with previously published mid-term results of the same cohort of patients. Results: Patients generally remained clinically asymptomatic or mildly symptomatic at final follow-up, which is reflected by a KOOS pain score of 33 points (maximum 36 points) and an IKDC total subjective score of 87% (maximum 100%). There was a significant difference between mid-term and final follow-up in terms of the function score of the IKDC subjective questionnaire (p = 0.031), compartment findings and donor site morbidity of the IKDC functional examination (both p = 0.034), and the total KOOS score (p = 0.047). The KL score indicated significant progression of OA from mid-term to final follow-up in the injured knees (p = 0.004) and healthy contralateral knees (p = 0.014). Mean OA grades of the injured knees were significantly higher compared with the healthy contralateral side (p = 0.006) at final follow-up, and two patients showed moderate to severe signs of OA in the injured knee. Conclusions: Although most patients remained clinically asymptomatic or mildly symptomatic, long-term progression of OA after isolated ACL reconstruction in athletes was significantly higher compared with the healthy contralateral knee.