Prevalence of Associated Lesions in Anterior Cruciate Ligament Reconstruction: Correlation With Surgical Timing and With Patient Age, Sex, and Body Mass Index

High prevalence of associated injuries in anterior cruciate ligament tears: A detailed magnetic resonance imaging analysis of 254 patients

OBJECTIVES

To evaluate the type and prevalence of associated injuries by using magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) tears.

METHODS

Data from the Natural Corollaries and Recovery after ACL injury multicenter longitudinal cohort study were analyzed. Between May 2016 and October 2018, patients aged between 15 and 40 years, who had experienced an ACL tear within the last 6 weeks and sought medical attention at one of seven healthcare clinics in Sweden, were invited to participate. The mean time from injury to MRI was 19.6 ± 15.2 days. An orthopedic knee surgeon and a musculoskeletal radiologist reviewed all the MRI scans. The following structures were assessed: posterior cruciate ligament (PCL), medial collateral ligament (MCL) complex, lateral collateral ligament (LCL), popliteus tendon, medial meniscus (MM), lateral meniscus (LM), and cartilage. In addition, the presence of bone bruising, impaction fractures in the lateral femoral condyle (LFC) or posterolateral tibia (PLT), and Segond fractures were also assessed.  RESULTS: A total of 254 patients (48.4% males) with a mean age of 25.4 ± 7.1 years were included. The prevalence of associated injuries was as follows: PCL (0.4%), MCL {41.3% [superficial MCL and deep MCL (dMCL) 16.5%; isolated dMCL 24.8%]}, LCL (2.4%), MM (57.4%), LM (25.2%), cartilage (15.0%), bone bruising (92.9%), impaction fracture in the LFC (45.7%) and PLT (4.7%), and Segond fracture (7.5%).

CONCLUSIONS

The prevalence of associated injuries in patients with ACL tears was high. The findings reported in this study may serve as a reference tool for orthopedic surgeons and radiologists in the diagnosis of associated injuries using MRI in patients with ACL tears.

The Impact of Time to Anterior Cruciate Ligament Reconstruction on Return to Duty Among Active Duty Military Personnel

INTRODUCTION

After an anterior cruciate ligament (ACL) injury, service members often undergo ACL reconstruction (ACLR) to restore knee stability, which is critical for performing physically demanding and unconventional military-specific tasks. Despite advancements in surgical techniques and rehabilitation protocols, a large portion of service members will not fully return to duty (RTD) post-ACLR and will receive a permanent profile restriction (PP) or undergo a medical evaluation board (MEB). The timing of ACLR is a modifiable factor that can potentially impact RTD and remains underexplored in this population. This study aimed to assess the relationship between the timing of ACLR and its impact on RTD and meniscal procedures performed at index ACLR.

METHODS

This retrospective observational study was conducted among active duty military personnel who underwent primary ACLR at Madigan Army Medical Center between October 1, 2016, and December 31, 2022. The primary outcome was the number of RTD, PP, or MEB outcomes. Secondary outcomes included the incidence and type of meniscal procedure performed at index ACLR. Kruskal-Wallis analyses were employed to assess the relationships between time to ACLR and RTD, as well as the incidence and type of meniscal procedure performed. After separating time to ACLR into four distinct time-based groups (0-3 months, 3-6 months, 6-12 months, and >12 months), a chi-squared test with post hoc analysis via Dunn's test with Bonferroni correction was conducted to identify a time interval from injury to ACLR that impacted RTD.

RESULTS

Initial analysis to assess the relationship between time to ACLR and outcome (RTD, PP, or MEB) were significant (P = .02). Subsequent analyses performed between 4 distinct time-based groups (0-3 months, 3-6 months, 6-12 months, and >12 months) were also significant (P = .03). Pairwise comparisons revealed an 80% rate of RTD in the 0-3 month group compared to a 53% RTD rate in 3-6 month group (P = .006). However, comparisons between the 3-6 month and 6-12 month group (P = .68) and between the 6-12 month and greater than 12 month groups were not significant (P = .80).Additionally, time to ACLR significantly differed between service members who did not undergo any concurrent meniscal procedure to those who had a meniscal debridement (P = .002), and to those who underwent meniscal repair (P = .02). There was no significant difference in time to ACLR between those who underwent debridement versus repair (P = .22). Patients without any meniscal procedure had an average surgery time of 175 days, compared to 240 days for those undergoing meniscal repair and 295 days for those with meniscal debridement.

CONCLUSION

The findings from this novel study suggest that ACLR within 3 months after injury can improve the likelihood of RTD without limitations. The timing of ACLR can also impact the incidence and type of meniscal procedures, as patients who did not undergo any concomitant meniscal procedures underwent ACLR within 6 months after injury. This study offers valuable insight into the importance of earlier ACLR among service members to improve RTD rates and decrease additional concomitant meniscal procedures.

Arthroscopic Primary Repair of Proximal Anterior Cruciate Ligament Tears Using a Continuous Bundle Suture Technique With Simplified Suture Passing

Anterior cruciate ligament (ACL) injury is a common knee sports injury, with proximal ACL tears accounting for most cases. Arthroscopic ACL preservation has shown great potential in repairing ACL anatomic and biological function, with less tissue damage and slightly higher failure rates. Although many techniques for repairing the ACL have been developed, there are still many problems with the existing technology, such as the cumbersome operation of the traditional hook and needle breakage of the Scorpion suture passer (Arthrex). Herein, to further improve operational convenience and reliability, we developed a continuous bundle suture technique for primary repair of proximal ACL tears with suture anchor fixation. This technique aims to achieve continuous suturing with no additional auxiliary suture for guiding suturing by using a passer as a pusher in the suture hook to push out the suture loaded in the tip of the hook after the hook passes through the ligament. This technique takes advantage of the economics of the suture hook and the convenience of the Scorpion suture passer, allowing for flexible application of the suture hook to conveniently achieve anteromedial and posterolateral bundle repair for patients with proximal ACL tears.

After 40 days intra-articular injury, risk profile increases linearly with time to surgery in adolescent patients undergoing primary anterior cruciate ligament reconstruction

PURPOSE

Anterior cruciate ligament (ACL) injuries are becoming more common in youth athletes. Time-to-surgery has been shown to significantly affect the rates of concurrent injuries at the time of ACL reconstruction (ACLR). The purpose of this study was to evaluate if time-to-surgery in ACLR impacts observances of intra-articular injuries and to categorize injury profile in relation to time.

METHODS

An Institutional Review Board-approved retrospective cohort study was conducted. Included subjects were aged 21 and below and underwent primary ACLR within 6 months of injury between January 2012 and April 2020. Skeletal maturity was determined via imaging. Laterality, location and severity/pattern of meniscal and chondral injuries were recorded. Multivariate logistic regression was utilized to identify risk factors for intra-articular pathology. Cut-off analyses were added to regression models to identify trends of concurrent injuries.

RESULTS

Eight hundred and fifty patients met the inclusion criteria. Patients with observed articular cartilage injuries had a significantly longer time-to-surgery of 66 days (p = 0.01). Risk factors for chondral injury were time-to-surgery (p = 0.01) and skeletal maturity (p = 0.01), while medial meniscal tears were prognosticated by time-to-surgery (p = 0.03), skeletal maturity (p = 0.01) and body mass index (p = 0.00). Cut-off analysis showed that after 40 days the proportion of patients with observed chondral injury increased with time to surgery and that there were significantly different observances of chondral (p = 0.00) and medial meniscal (p = 0.03) injuries in the 6-week model, as compared to the continuous time model.

CONCLUSION

Longer time-to-surgery in ACLR is associated with higher rates of concomitant intra-articular pathology, especially chondral injuries. After 40 days, the observed rates of intra-articular injury increase proportionately with time from injury. A 6-week categorical model best stratifies intra-articular injury risk profile. Risk factor analysis identified skeletally mature patients with delayed surgery of >12 weeks to be at the highest risk for both chondral and medial meniscal injuries after an ACLR.

LEVEL OF EVIDENCE

Level III.

A higher incidence of chondral injuries on the medial femoral condyle in concomitant ACL ruptures, no significant difference in treatment: A systematic review

PURPOSE

The associated damage to articular cartilage in anterior cruciate ligament (ACL) injured patients is a well-recognized phenomenon; however, there is a relative paucity in the literature regarding the different treatment techniques and outcomes. The purpose of this systematic review was to identify patients treated for acute ACL rupture and associated cartilage injury, with interest in the surgical management of these chondral injuries and any difference in patient-reported outcome measures (PROMs) differing techniques.

METHODS

A systematic review was performed looking for treatment or management of International Cartilage Repair Society grade 3 or 4 articular cartilage injury at the time of ACL reconstruction.

RESULTS

Seventeen studies fit the criteria, a total of 892 patients were included, 64.6% were male with a mean age of 33.7 and the average time to follow-up was 41.7 months. 68.2% of the lesions were on the medial femoral condyle (MFC) with a mean lesion size of 3.9 cm2. Six different operative methods of dealing with chondral lesions were identified, there was no significant difference in PROMs between the techniques, although there was a significant difference between the preoperative and postoperative outcome measures.

CONCLUSIONS

The systematic review found that chondral defects on the MFC are more common in concomitant ACL injuries, despite the pattern of bone bruising being more common on the lateral femoral condyle as reported in the literature. It also found no significant difference in the PROMs between the six different techniques identified for the concomitant management of ACL reconstruction and chondral defects.

LEVEL OF EVIDENCE

Level II.

Articular Cartilage Damage in the Patellofemoral Compartment at ACL Reconstruction Predicts Poor Postoperative Subjective Outcomes in Patients Age 40 and Older

The purpose of this study was to investigate factors that influence clinical outcomes after anterior cruciate ligament (ACL) reconstruction in patients aged ≥40 years. We studied 264 patients aged ≥40 and 154 patients aged ≤20 years who underwent ACL reconstruction at several surgical centers. A logistic regression analysis was conducted to identify factors that influenced the Knee Injury and Osteoarthritis Outcome Score (KOOS) at 1 year post-ACL reconstruction. In the older patient group, cartilage damage in the patellofemoral compartment at surgery was a significant risk factor for poor postoperative KOOS subscores (pain, activities of daily living [ADL], sports, and quality of life [QOL]). Articular cartilage damage in the lateral compartment also significantly influenced one of the postoperative KOOS subscores (symptoms). In the younger patient group, articular cartilage damage in any compartments did not influence the postoperative KOOS subscores; only two preoperative KOOS subscores (symptoms and QOL) significantly influenced their postoperative KOOS subscores. We concluded that the articular cartilage damage in the patellofemoral compartment at ACL reconstruction predicts poor KOOS subscores at the 1-year follow-up in patients aged ≥40 years. STUDY DESIGN:  Cohort study (Prevalence); Level of evidence, 2.

Relationship Between Revision Rate, Osteoarthritis, and Obesity for ACL Reconstruction: A Nationwide Retrospective Cohort Study

Background

The long-term goal of anterior cruciate ligament (ACL) reconstruction is to prevent secondary osteoarthritis due to instability. Obesity itself is also a risk factor for osteoarthritis and shows an increase in its incidence, but little is known about the relationship between obesity and the outcome of ACL reconstruction.

Purpose/Hypothesis

This study aimed to determine the relationship between the outcome of ACL reconstruction and obesity. It was hypothesized that obesity would be associated with the revision rate of ACL reconstruction and additional surgical treatment for osteoarthritis in patients who undergo ACL reconstruction.

Study design

Cohort study; Level of evidence, 3.

Methods

Claims and health screening data of the National Health Insurance Service were used to analyze patients who underwent ACL reconstruction between January 1, 2003, and December 31, 2021. The association between obesity and risk of revision ACL reconstruction and additional surgical treatment for osteoarthritis or meniscal lesion was analyzed. Body mass index (BMI) was used to classify patients as underweight (BMI, <18.5), normal weight (BMI, 18.5-24.9), overweight (BMI, 25.0-29.9), obese (BMI, 30.0-39.9), or morbidly obese (BMI, ≥40.0). Multivariable Cox proportional hazards model analysis was conducted.

Results

A total of 56,734 patients were included. Of them, 311 (0.5%) patients were underweight, 26,613 (46.9%) were normal weight, 24,372 (43.0%) were overweight, 5324 (9.4%) were obese, and 114 (0.2%) patients were morbidly obese. The underweight group showed a significantly lower risk of revision ACL reconstruction than the normal weight group (hazard ratio [HR], 0.54; 95% CI, 0.31-0.93; P = .0273). However, the overweight, obese, and morbidly obese groups had no significant difference from the normal weight group. The risk of high tibial osteotomy (HTO) or total knee arthroplasty (TKA) was significantly high for the overweight (HR, 1.93; 95% CI, 1.70-2.19; P < .0001) and obese (HR, 2.71; 95% CI, 2.23-3.30; P < .0001) groups. Subgroup analysis performed in patients ≥40 years of age for the risk of HTO showed a significant increased risk in the overweight group (HR, 1.889; 95% CI, 1.56-2.29; P < .0001) and obese group (HR, 2.78; 95% CI, 2.10-3.69; P < .0001). Subgroup analysis performed in patients ≥50 years of age for the risk of TKA also showed a significant increased risk in the overweight group (HR, 2.03; 95% CI, 1.67-2.47; P < .0001) and obese group (HR, 2.53; 95% CI, 1.83-3.50; P < .0001). After adjusting for meniscal injury at index surgery by multivariate regression analysis, 1.87- and 2.75-fold increased risks of HTO were identified for the overweight and obese groups, respectively, for patients aged >40 years. For patients aged >50 years, 2.02-fold and 2.52-fold increased risks of TKA were observed for the overweight and obese groups, respectively. The risk of additional surgery due to the meniscal lesion was high for the overweight (HR, 1.09; 95% CI, 1.03-1.15; P = .002) and obese (HR, 1.10; 95% CI, 1.01-1.21; P = .0351) groups, while no significant difference was found for the underweight and morbidly obese groups.

Conclusion

This study highlights that obesity does not increase the revision rate of ACL reconstruction. However, the risk of additional surgical treatment for osteoarthritis and meniscal lesions increased as BMI increased. Further investigation is needed to determine the efficacy of ACL reconstruction for preventing osteoarthritis in obese patients.

Lateral extra-articular tenodesis in association to All-inside anterior cruciate ligament reconstruction does not modify return to play in basketball players: A comparative cohort study

INTRODUCTION

Return to play rates after anterior cruciate ligament (ACL) reconstruction range between 50-98% depending on sport professionality, without being modified by the addition of an extra-articular augmentation (EA). The objective of the study is to describe the rate of return to play in our cohort. The hypothesis is that the addition of EA increases that rate.

MATERIAL AND METHODS

A retrospective, descriptive and analytical study of a 130 basketball players cohort between 18 and 45 years old, whom underwent ACL reconstruction between the years 2018 and 2022, with a minimum follow-up of 18 months. Data was collected by reviewing medical records. IKDC score was registered after one year from surgery. All patients operated from 2020 received an extra-articular tenodesis.

RESULTS

Of all patients, 72.31% returned to training, 70.77% returned to competition and 46.15% returned to the same level of performance prior to injury. The EA group (46.15%) did not increase the rate of return to competition (P=.552) nor to the same level of performance (P=.664). The mean IKDC. score was 86.83 (SD 14.85), and was not higher in the EA group (P=.418). However, its value was higher in the players who returned to training, competition and level of performance (P<.05). EA did not delay the return to play in any group (P=.282).

CONCLUSION

To sum up, the EA does not modify the return to sport rate. Higher IKDC values predict a greater return to sport rate. in all groups. Prospective studies with larger sample size and longer follow-up time are required.

Male Sex, Revision Surgery, Low Volume of Anterior Cruciate Ligament Remnant, and Significant Instability Are Risk Factors for Posterior Root Tear of the Lateral Meniscus in Patients Undergoing Anterior Cruciate Ligament Reconstruction

PURPOSE

To determine the incidence of lateral meniscus posterior root tears (LMPRTs) in patients undergoing anterior cruciate ligament (ACL) reconstruction and identify associated risk factors.

METHODS

We conducted a retrospective, multicenter study using data from the Francophone Arthroscopic Society's registry. The study included all the patients in the registry who underwent ACL reconstruction surgery between June 2020 and June 2023; we excluded incomplete data. We compared delay from injury to surgery between LMPRTs group and no-LMPRTs group. Variables investigated as potential risk factors for LMPRTs included age, sex, nature of surgery (primary or revision), pivot shift test result, side-to-side laxity under anesthesia, presence of ACL remnant, occurrence of medial meniscal tear, and presence of collateral ligament injury. Risk factors were analyzed using a logistic regression model.

RESULTS

Among the 5,359 patients analyzed, LMPRTs occurred in 7.0% (n = 375) of cases during ACL reconstruction. Mean age at surgery was 29.3 ± 10.3 years old [11-77]. Concerning delay to surgery, the mean time was 8.4 ± 23.1 weeks [0.0-347.2] in the no-LMPRTs group and 6.5 ± 10.2 weeks [0.2-61.6] in the LMPRTs group (P = .109). Univariate analysis revealed that male sex (P < .001), revision surgery (P < .001), medial meniscal injury (P = .007), ACL remnant (0% vs >70%, <10% vs >70%, 10%-30% vs >70%, >30%-50% vs >70%, >50%-70% vs >70%; P < .001), and greater pivot shift grade (P = .011) were significantly associated with a presence of LMPRTs. Age, side-to-side laxity, and collateral ligament injury were not found to be significant risk factors. In multivariate analysis, male sex, revision surgery, pivot shift test result, and a low volume of ACL remnant remained significant. Side-to-side laxity was also a significant factor in multivariate analysis.

CONCLUSIONS

This study identified male sex, revision surgery, low volume of ACL remnant, side-to-side laxity, and greater grade of pivot shift as significant risk factors for LMPRTs during ACL reconstruction.

LEVEL OF EVIDENCE

Level III, retrospective comparative case series.

Acute Anterior Cruciate Ligament Reconstruction Performed Within 10 Days of Injury Does Not Increase Risk of Postoperative Arthrofibrosis: A Systematic Review and Meta-analysis

BACKGROUND

The optimal timing of anterior cruciate ligament (ACL) reconstruction (ACLR) remains a controversial topic. Previous reviews have demonstrated that there are no differences between early and delayed ACLR; however, these studies have been limited by heterogeneous definitions of acute ACL injury.

PURPOSE

To evaluate postoperative patient functional outcomes and risk for arthrofibrosis after acute arthroscopic ACLR performed ≤10 days after injury.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using multiple medical databases. Inclusion criteria were studies that evaluated postoperative range of motion outcomes for patients undergoing ACLR ≤10 days after initial ACL injury. For included comparative studies comparing patient groups undergoing ACLR ≤10 days and patients undergoing "delayed" ACLR after ≥3 weeks of initial injury, quantitative analysis was performed to assess for differences in postoperative arthrofibrosis, reoperation rates, and patient-reported outcomes between groups. DerSimonian-Laird binary random-effects models were constructed to quantitatively describe the association between the ACLR time period and patient outcomes by generating effect estimates in the form of odds ratios with 95% CIs. Qualitative analysis was performed to describe variably reported patient outcomes and the risk of arthrofibrosis after ACLR for noncomparative studies.

RESULTS

Screening yielded 6 full-text articles with 448 patients who underwent ACLR (296 ACLR <10 days, 152 ACLR >3 weeks), with a pooled mean age of 28.1 years. For studies amenable to quantitative analysis, there were no significant differences between ACLR performed ≤10 days and ACLR performed at the 3-week point or after in terms of postoperative stiffness (3 studies; odds ratio, 1.27; P = .508), Tegner scores (2 studies; mean difference, -0.056; P = .155), or reoperation for stiffness (3 studies; odds ratio, 0.869; P = .462). The overall incidence of postoperative arthrofibrosis after 12 months of follow-up was 11 of 296 (3.7%) for ACLRs performed ≤10 days versus 6 of 152 (3.9%) for those performed at the 3-week point or after.

CONCLUSION

ACLR performed ≤10 days after the inciting injury does not increase the risk of postoperative arthrofibrosis and demonstrates similar patient-reported outcomes compared with ACLR performed at the 3-week point or after.

The Effect of Greater Area Deprivation and Medicaid Insurance Status on Timing of Care and Rate of Reinjury After Anterior Cruciate Ligament Reconstruction

Background

Lower socioeconomic status and public insurance lead to a longer delay to surgery and a higher likelihood of concomitant pathology before undergoing anterior cruciate ligament reconstruction (ACLR). However, few studies have examined the influence of community deprivation on ACLR timing and outcomes.

Purpose/Hypothesis

The primary aim of this study was to define the effect of the area deprivation index (ADI) and insurance classification on access to orthopaedic care after an ACL rupture, and the secondary aim was to determine whether these variables were associated with a second ACL injury after primary ACLR. It was hypothesized that patients with a greater national ADI percentile and Medicaid insurance would experience longer delays to care and an increased risk of reinjury after ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective study was performed to evaluate patients undergoing primary ACLR between 2016 and 2019. The national ADI percentile was obtained utilizing the Neighborhood Atlas website. The relationship between national ADI percentile and care characteristics (eg, time to specialized care) was investigated using the Spearman rho correlation coefficient (r). The association between patient and care characteristics and second ACL injury after the index procedure (ie, graft rerupture or contralateral ACL rupture) was investigated using binary logistic regression.

Results

A total of 197 patients met the inclusion criteria. Longer times from injury to surgery (r = 0.238; P < .001) and from specialized care to surgery (r = 0.217; P = .002) were associated with a greater national ADI percentile. The second injury group reported significantly greater national ADI (P = .026) and included a greater percentage of patients with Medicaid insurance (31.3%) compared with the no second injury group. Patients experienced 5.1% greater odds of a second ACL injury for each additional month between evaluation and surgery.

Conclusion

Greater national ADI percentile and Medicaid insurance status were associated with adverse ACLR timing and outcomes. Patients with a greater national ADI percentile took significantly longer to obtain surgery after ACL injury. Those who sustained a second ACL injury after ACLR had an overall higher mean national ADI percentile and included a greater proportion of patients with Medicaid compared with those who did not sustain a second ACL injury. Future studies should critically investigate the underlying factors of these associations to reach equity in orthopaedic care.

Health-related quality of life does not deteriorate while waiting for anterior cruciate reconstruction

PURPOSE

The aim of this study was to determine how preoperative health-related quality of life (HRQoL) is affected by the duration of the wait time (WT) for anterior cruciate ligament reconstruction (ACLR) once a decision is made to proceed with surgery.

METHODS

This was a multi-centre prospective cohort study. One hundred and twenty-two patients 14 years of age and above waiting for ACLR completed the International Knee Documentation Committee (IKDC) demographic, current health assessment and subjective knee evaluation (SKF) forms on the day of decision to operate and the day of surgery. Changes in scores were analyzed for the entire cohort, adjusted for WTs and a subset was compared for patients with isolated anterior cruciate ligament (ACL) tears and ACL tears with concurrent meniscal involvement. Changes in HRQoL scores from the day of the decision to operate to the 9-month postoperative appointments were also assessed.

RESULTS

Energy/Fatigue (p < 0.05), Pain (p < 0.05), General Health (p < 0.05) and the IKDC-SKF Score (p < 0.05) significantly increased between the day of the decision to operate and the day of surgery. Only the change in IKDC-SKF score remained significantly higher after adjusting for WT. Baseline HRQoL scores significantly improved by the 9-month postoperative appointment.

CONCLUSION

The length of time waiting for ACLR did not adversely influence HRQoL in this study. However, low preoperative HRQoL and the significant improvement in HRQoL of patients followed postoperatively suggest that timely surgery is beneficial for this patient population.

LEVEL OF EVIDENCE

Level II.

Impact of Surgical Timing on Functional Outcomes after Anterior Cruciate Ligament Reconstruction

Objectives: Although acute anterior cruciate ligament reconstruction (ACLR) is often avoided because of postoperative joint stiffness, delayed ACLR can lead to a longer recovery time and can have a negative impact on physical function due to detraining. This study aimed to determine the effects of acute ACLR on postoperative outcomes, including muscle strength, performance, and return to sports. Methods: A total of 110 patients who underwent anatomical ACLR using hamstring autografts were included in this study and were divided into three groups: acute (ACLR performed within 2 weeks after ACL injury), 2-6 weeks (ACLR performed between 2 and 6 weeks after injury), and 6-12 weeks (ACLR performed between 6 and 12 weeks after injury). Several parameters were evaluated, including range of motion, knee joint stability, isokinetic knee strength, performance, and return to sports. Results: No significant differences were found in the range of motion or knee joint stability between the groups. The acute group exhibited significantly greater quadriceps strength at 3 months postoperatively than the other groups (p < 0.05). The single-leg hop test showed that 66.7%, 38.7%, and 33.3% of the patients in the acute, 2-6 weeks, and 6-12 weeks groups, respectively, recovered to an LSI of 90% or greater (p = 0.09, Cramer's V = 0.27). All patients in the acute group were able to return to sports (p = 0.14; Cramer's V = 0.28). Conclusions: Acute ACLR is advantageous for the early recovery of strength and performance without adverse events. Acute ACLR may shorten the time spent away from sports activities.

Delaying anterior cruciate ligament reconstruction for more than 3 or 6 months results in lower risk of revision surgery

BACKGROUND

The objective of this study is to investigate the risk of revision surgery when delaying anterior cruciate ligament reconstruction (ACLR) past 3 months or 6 months after injury.

MATERIALS AND METHODS

A total of 30,280 patients with isolated ACLR were identified in the Danish Knee Ligament Reconstruction Registry and divided into four groups; ACLR < 3 months, > 3 months, < 6 months, or > 6 months after injury. Primary outcome was revision surgery and secondary outcome were objective and subjective clinical outcome. The 2 year relative risk, crude, and adjusted hazard ratio (HR) were calculated.

RESULTS

Comparing ACLR < 3 months to ACLR > 3 months of injury the 2 year relative risk of revision surgery was found to be 1.81 (95% CI 1.46-2.23; P < 0.001) with an adjusted hazard ratio (HR) of 1.27 (95% CI 1.12-1.44; P < 0.001). Comparing ACLR < 6 months to ACLR > 6 months of injury the 2 year relative risk of revision surgery was found to be 1.61 (95% CI 1.34-1.92; P < 0.001) with an adjusted HR of 1.27 (95% CI 1.15-1.40; P < 0.001).

CONCLUSION

The risk of revision ACLR surgery was found to be increased when ACLR was performed within 3 months or 6 months of injury compared with later surgery. The 1 year postoperative objective knee laxity and the subjective patient-related outcome was found to be without a clinically significant difference; however, those with early ACLR (< 3 months or < 6 months) were found to have a higher activity level 1 year postoperatively. The information about increased risk of revision when having early surgery should be informed to patients when deciding timing of ACLR treatment.

LEVEL OF EVIDENCE

II.

Lateral Meniscus Zip Lesion of Knee: Classification and Repair Methods

Lateral meniscus tears at the junction of the Wrisberg ligament and posterior horn are meniscocapsular injuries often seen with injury to the anterior cruciate ligament. Such lateral meniscus posterior horn lesions have been termed zip lesions. The lateral meniscus posterior horn is the major restraint for the pivot shift maneuver. Considering the morphology of condyles, lateral meniscus preservation and repair of unstable meniscocapsular posterior tear are needed to prevent future osteoarthritis. In this Technical Note, we aim to classify zip lesions of the posterior horn of the lateral meniscus. Zip lesions are located posteriorly and often are missed on magnetic resonance imaging and routine diagnostic arthroscopy. We recommend looking from the anteromedial portal and exploring the posterolateral compartment to identify hidden zip lesions, equivalent to medial-sided ramp lesions. We describe various all-inside techniques to repair these inaccessible tears.

Treatment of knee cartilage lesions in 2024: From hyaluronic acid to regenerative medicine

Abstract

Intact articular cartilage plays a vital role in joint homeostasis. Local cartilage repairs, where defects in the cartilage matrix are filled in and sealed to congruity, are therefore important treatments to restore a joint equilibrium. The base for all cartilage repairs is the cells; either chondrocytes or chondrogeneic cells from bone, synovia and fat tissue. The surgical options include bone marrow stimulation techniques alone or augmented with scaffolds, chondrogeneic cell implantations and osteochondral auto- or allografts. The current trend is to choose one-stage procedures being easier to use from a regulatory point of view. This narrative review provides an overview of the current nonoperative and surgical options available for the repair of various cartilage lesions.

Level of Evidence

Level IV.

Prevalence and Predictors of Concomitant Meniscal Surgery During Pediatric and Adolescent ACL Reconstruction: Analysis of 4729 Patients Over 20 Years at a Tertiary-Care Regional Children's Hospital

Background

The rate of concomitant meniscal procedures performed in conjunction with anterior cruciate ligament (ACL) reconstruction is increasing. Few studies have examined these procedures in high-risk pediatric cohorts.

Hypotheses

That (1) the rates of meniscal repair compared with meniscectomy would increase throughout the study period and (2) patient-related factors would be able to predict the type of meniscal operation, which would differ according to age.

Study Design

Cohort study (prevalence); Level of evidence, 2.

Methods

Natural language processing was used to extract clinical variables from notes of patients who underwent ACL reconstruction between 2000 and 2020 at a single institution. Patients were stratified to pediatric (5-13 years) and adolescent (14-19 years) cohorts. Linear regression was used to evaluate changes in the prevalence of concomitant meniscal surgery during the study period. Logistic regression was used to determine predictors of the need for and type of meniscal procedure.

Results

Of 4729 patients (mean age, 16 ± 2 years; 54.7% female) identified, 2458 patients (52%) underwent concomitant meniscal procedures (55% repair rate). The prevalence of lateral meniscal (LM) procedures increased in both pediatric and adolescent cohorts, whereas the prevalence of medial meniscal (MM) repair increased in the adolescent cohort (P = .02). In the adolescent cohort, older age was predictive of concomitant medial meniscectomy (P = .031). In the pediatric cohort, female sex was predictive of concomitant MM surgery and of undergoing lateral meniscectomy versus repair (P≤ .029). Female sex was associated with decreased odds of concomitant LM surgery in both cohorts (P≤ .018). Revision ACLR was predictive of concomitant MM surgery and of meniscectomy (medial and lateral) in the adolescent cohort (P < .001). Higher body mass index was associated with increased odds of undergoing medial meniscectomy versus repair in the pediatric cohort (P = .03).

Conclusion

More than half of the young patients who underwent ACLR had meniscal pathology warranting surgical intervention. The prevalence of MM repair compared with meniscectomy in adolescents increased throughout the study period. Patients who underwent revision ACLR were more likely to undergo concomitant meniscal surgeries, which were more often meniscectomy. Female sex had mixed effects in both the pediatric and adolescent cohorts.

Incidence of and Risk Factors for Medial Meniscal Lesions at the Time of ACL Reconstruction: An Analysis of 4697 Knees From the SANTI Study Group Database

BACKGROUND

Medial meniscal (MM) lesions (MMLs) are a common finding at the time of anterior cruciate ligament reconstruction (ACLR). It is recognized that evaluation of the posteromedial compartment reduces the rate of missed MML diagnoses.

PURPOSE

To determine the incidence of MMLs in patients undergoing ACLR, when using a standardized arthroscopic approach that included posteromedial compartment evaluation, as well as to determine how the incidence of MMLs changed with increasing time intervals between injury and surgery, and to investigate what risk factors were associated with their presence.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective analysis of prospectively collected data was performed. All patients who underwent primary ACLR between January 2013 and March 2023 were considered for study eligibility. The epidemiology was defined by categorizing and reporting the incidence and categorizing the spectrum of MM tear types. Risk factors associated with MMLs were analyzed using a logistic regression model.

RESULTS

MMLs were identified in 1851 (39.4%) of 4697 consecutive patients undergoing ACLR. The overall incidence of MMLs was 33.1% for the period of 0 to 3 months, 38.7% for the period of 3 to 12 months, and 59.6% for the period of >12 months. The overall incidence of MMLs increased with longer durations of time between injury and surgery, along with significant increases in complex, bucket-handle, ramp, and/or flap lesions. The largest increase in incidence of MMLs was observed for complex MM tear patterns. Risk factors associated with MMLs included time between injury and surgery >3 months (odds ratio [OR], 1.320; 95% CI, 1.155-1.509; P < .0001) and >12 months (OR, 3.052; 95% CI, 2.553-3.649; P < .0001), male sex (OR, 1.501; 95% CI, 1.304-1.729; P < .0001), body mass index (BMI) ≥25 (OR, 1.193; 95% CI, 1.046-1.362; P = .0088), and lateral meniscal lesion (OR, 1.737; 95% CI, 1.519-1.986; P < .0001).

CONCLUSION

Overall, MMLs were identified in 39.4% of 4697 patients undergoing ACLR when posteromedial compartment evaluation was performed in addition to standard anterior viewing. The incidence of MMLs and the complexity of tear types increased significantly with increasing time intervals between the index injury and ACLR. Secondary risk factors associated with an increased incidence of medial meniscal tears include male sex, increased BMI, and lateral meniscal lesions.

The optimal window for reconstruction of the anterior cruciate ligament (ACL) with respect to quadriceps atrophies lies within 21 to 100 days

PURPOSE

The study's objective was to determine the optimal window for anterior cruciate ligament (ACL) reconstruction with respect to quadriceps atrophies and clinical outcome.

METHODS

For this retrospective, comparative study, 115 patients aged under 35 were included, who received an ACL reconstruction between 2011 and 2016. They were divided into four groups, depending on the time to surgery, to determine the optimal window for reconstruction: (group 1: ≤21 d, group 2: <21d-56d≥, group 3: >56d-100d≥, group 4: >100d). Follow-up was performed one month postoperatively, after a mean of 4.9 (±5.3) months, and after a mean of 3.5 (±1.4) years. Primary endpoints included quadriceps muscle status, range of motion (ROM), pain, swelling, the International Knee Documentation Committee Subjective Knee Form (IKDC), the Lysholm-Score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Tegner-Activity-Scale (TAS).

RESULTS

Significantly more quadriceps atrophies were observed in group 1 and group 4, representing reconstructions earlier than 21 and later than 100 days (29% and 41% vs. 9%; p = 0.032). The measurements of knee extension (p = 0.082) and ROM (p = 0.123) were comparable in all groups. Group 1 showed the least pain (0% vs. 15%; p = 0.285) and swelling (0% vs. 23%; p = 0.077) compared to all other groups one month postoperatively. A comparison of postoperative clinical scores revealed no significant differences, with group 1 exhibiting the lowest TAS levels.

CONCLUSION

In patients who underwent ACL reconstruction within three weeks or after more than 100 days, a significantly higher incidence of quadriceps atrophy was observed, possibly attributable to the initial inflammatory phase or the delayed reconstruction affecting quadriceps function. However, this impairment may not be observable in elite athletes who undergo reconstruction within hours of the injury.

Prevalence and Predictors of Concomitant Meniscal and Ligamentous Injuries Associated With ACL Surgery: An Analysis of 20 Years of ACL Reconstruction at a Tertiary Care Children's Hospital

BACKGROUND

There is an increasing rate of procedures being performed for concomitant injuries during anterior cruciate ligament (ACL) surgery. Few studies have examined risk factors for these associated injuries in young patients.

HYPOTHESIS

There are patient-related factors predictive of concomitant knee pathology that differ between age-based cohorts.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Natural language processing was used to extract clinical variables from available notes of patients undergoing ACL surgery between 2000 and 2020 at a single institution (5174 ACL surgeries; mean age, 17 ± 4 years; 53.1% female; accuracy, >98%). Patients were stratified to pediatric (5-13 years), adolescent (14-19 years), and young adult (20-35 years) cohorts. Logistic regression was used to determine predictors of concomitant injury to the menisci, medial collateral ligament (MCL), posterolateral corner (PLC), and posterior cruciate ligament (PCL).

RESULTS

Between 2000 and 2020, 54% of pediatric, 71% of adolescent, and 70% of adult patients had ≥1 concomitant soft tissue injury. In children and adolescents, increased age was consistently predictive of sustaining a concomitant injury (P < .02). Female children had increased odds of concomitant medial meniscal injury, while female adults had decreased odds (P≤ .046). Adolescent and adult female patients had decreased odds of concomitant lateral meniscal injury (P≤ .027). Female children had increased odds of injury to the MCL (P = .015), whereas female children and adolescents had decreased odds of PCL injury (P≤ .044). Adolescents undergoing revision ACL surgery had increased odds of meniscal injury (P≤ .001) and decreased odds of concomitant MCL injury (P = .028). Increased body mass index (BMI) was associated with increased odds of concomitant medial meniscal injury in all cohorts (P≤ .041), lateral meniscal injury in adults (P = .045), and PLC injury in children (P = .016). Contact injuries were associated with increased odds of MCL injury in adolescents (P = .017) and PLC injury in adolescents and adults (P < .014).

CONCLUSION

These findings support the hypothesis, as there were multiple factors that significantly affected the risk of concomitant injuries that differed between cohorts. Increased age, BMI, and contact injury history were generally associated with increased odds of sustaining a concomitant injury, whereas female sex and revision ACL surgery had mixed effects. Further studies are essential to investigate the sex-based differences in risk for concomitant injuries and to develop tailored treatment plans that minimize the risk of secondary ACL injury.

Association of Emergency Department Evaluation With Public Insurance Use and Treatment Delays for ACL Injury

Background

Utilization of an emergency department (ED) visit for anterior cruciate ligament (ACL) injury is associated with high cost and diagnostic unreliability.

Hypothesis

Patients initially evaluated at an ED for an ACL injury would be more likely to be from a lower income quartile, use public insurance, and experience a delay in treatment.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients in the Rhode Island All Payers Claims Database who underwent ACL reconstruction (ACLR) between 2012 and 2021 were identified using the Current Procedure Terminology (CPT) code 29888. Patients were stratified into 2 cohorts based on CPT codes for ED or in-office services within 1 year of ACLR. A chi-square analysis was used to test for differences between cohorts in patient and surgical characteristics. Multivariable linear and logistic regression were used to determine how ED evaluation affected timing and outcome variables.

Results

While adjusting for patient and operative characteristics, patients in the ED cohort were more likely to have Medicaid (29% vs 12.5%; P < .001) and be in the lowest income quartile (44.6% vs 32.1%; P < .001). ED visit and Medicaid status were associated with increased time to (1) diagnostic magnetic resonance imaging, adding 7.97 days on average (95% CI, 4.14-11.79 days; P < .001) and 8.40 days (95% CI, 3.44-13.37 days; P = .001), respectively; and (2) surgery, adding 20.30 days (95% CI, 14.10-26.49 days; P < .001) and 12.88 days (95% CI, 5.15-20.60 days; P = .001), respectively. Patients >40 years who were evaluated in the ED were 2.5 times more likely to require subsequent ACLR (odds ratio, 2.50 [95% CI, 1.01-6.21]; P = .049).

Conclusion

In this study, patients who visited the ED within 1 year before ACLR were more likely to have a lower income, public insurance, increased time to diagnostic imaging, and increased time to surgery, as well as decreased postoperative physical therapy use and increased subsequent ACLR rates in the 40-49 years age-group.

High prevalence of associated intra-articular injuries with increasing time period from anterior cruciate ligament injury to reconstruction, even in apparent copers

BACKGROUND

It still unclear whether copers may bear the same time-sensitive risk of intra-articular injury as non-copers. The objectives were to investigate the clinical characteristics of copers and non-copers that have sustained an anterior cruciate ligament (ACL) injury, and to examine and compare the intra-articular pathologies in delayed ACL reconstruction (ACLR) in copers and noncopers.

METHODS

Patients who sustained ACL injury while participating in high-performance sports and opted for non-operative treatment were enrolled in this study. Depending on the occurrence of the knee giving way, patients were classified into copers and noncopers. Clinical characteristics were compared between the two groups. Additionally, intra-articular injuries were evaluated for those who eventually underwent delayed ACLR.

RESULTS

11 of the 75 patients (14.7%) were classified as copers. No major differences were found in the clinical characteristics between groups. Following the initial non-operative treatment, 67 patients underwent delayed ACLR. When examining intra-articular abrasions at the time of surgery, non-copers who continued sports activities for 3 to 12 months exhibited a significantly higher rate of injury as opposed to their coper counterparts. However, the difference in the prevalence of intra-articular lesions between the two groups in patients who continued to play sports for at least 12 months before surgery was nominal.

CONCLUSION

The rate of copers was relatively low in patients who resumed playing high-level sports after ACL injury. Additionally, even in copers, those who continued sports activities for more than 12 months had comparably high prevalence of intra-articular injuries with noncopers.

STUDY DESIGN

Retrospective case-control study; Level of evidence, 3.

Meniscal repair failure following concurrent primary anterior cruciate ligament reconstruction: results from the New Zealand ACL Registry

PURPOSE

This study aimed to identify the risk factors for meniscal repair failure following concurrent primary anterior cruciate ligament (ACL) reconstruction.

METHODS

Prospective data recorded by the New Zealand ACL Registry and the Accident Compensation Corporation were reviewed. Meniscal repairs performed during concurrent primary ACL reconstruction were included. Repair failure was defined as a subsequent reoperation involving meniscectomy of the repaired meniscus. Multivariate survival analysis was performed to identify the risk factors for failure.

RESULTS

A total of 3,024 meniscal repairs were analysed with an overall failure rate of 6.6% (n = 201) at a mean follow-up of 2.9 years (SD 1.5). The risk of medial meniscal repair failure was higher with hamstring tendon autografts (adjusted HR [aHR] = 2.20, 95% CI 1.36-3.56, p = 0.001), patients aged 21-30 years (aHR = 1.60, 95% CI 1.30-2.48, p = 0.037) and in patients with cartilage injury in the medial compartment (aHR = 1.75, 95% CI 1.23-2.48, p = 0.002). The risk of lateral meniscal repair failure was higher in patients aged ≤ 20 years (aHR = 2.79, 95% CI 1.17-6.67, p = 0.021), when the procedure was performed by a low case volume surgeon (aHR = 1.84, 95% CI 1.08-3.13, p = 0.026) and when a transtibial technique was used to drill the femoral graft tunnel (aHR = 2.30, 95% CI 1.03-5.15, p = 0.042).

CONCLUSION

The use of a hamstring tendon autograft, younger age and the presence of medial compartment cartilage injury are risk factors for medial meniscal repair failure, whereas younger age, low surgeon volume and a transtibial drilling technique are risk factors for lateral meniscal repair failure.

LEVEL OF EVIDENCE

Level II.

Risk Factors for Concomitant Meniscal Injury With Sport-Related Anterior Cruciate Ligament Injury

Background

Previous studies of concomitant meniscal injury in athletes with anterior cruciate ligament (ACL) injury have examined age, sex, body mass index (BMI), injury mechanism, and time from injury to surgery as potential risk factors.

Purpose

To identify additional risk factors for concomitant meniscal injury, including preinjury joint laxity and lower extremity alignment, in athletes with sport-related ACL injury.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

This study included 180 participants aged 13 to 26 years who underwent ACL reconstruction (ACLR) after a first-time ACL injury sustained during participation in sport. Contralateral lower extremity alignment and joint laxity were used as surrogate measures for the injured knee before trauma. Concomitant meniscal tear patterns were identified at the time of ACLR. Sex-specific analyses were conducted.

Results

Concomitant meniscal injury was observed in 60.6% of the subjects. The prevalence of concomitant injury was higher in male than female participants (69.9% vs 54.2%; P = .035) due to a higher prevalence of lateral meniscal injuries (56.2% vs 38.3%; P = .018). Among male patients, there was a significant difference in the prevalence of concomitant lateral meniscal tear according to sport participation (≥9 vs <9 h/week: 67.4% vs 35.7%; P = .032). Among male patients, the likelihood of concomitant injury to both the lateral and medial menisci increased by 28.8% for each 1-mm decrease in navicular drop. Among female patients, the likelihood of concomitant injury to the lateral meniscus increased by 15% per degree increase in genu recurvatum and 14% per degree decrease in standing quadriceps angle, with similar effects on the likelihood of concurrent injury to both the lateral and medial menisci.

Conclusion

Measures of lower extremity alignment and genu recurvatum previously identified as risk factors for ACL injury were also associated with concomitant meniscal injury in female patients while other risk factors, including BMI and joint laxity, were not. Increased time spent participating in sport and navicular drop were associated with concomitant meniscal injury in male patients.

Early ACL reconstruction shows an improved recovery of isokinetic thigh muscle strength compared to delayed or chronic cases

INTRODUCTION

The recovery of periarticular strength is a major criterion in return-to-play testing. The rationale of the study was to assess the impact of the delay of surgery (∆ between injury and surgery) on knee extensor and knee flexor strength of anterior cruciate ligament (ACL)-deficient patients six months after reconstruction.

MATERIALS AND METHODS

In a retrospective cohort study, all patients with ACL ruptures between 03/2015 and 12/2019 were analyzed. Inclusion criteria were isolated ACL rupture without any associated lesions undergoing a reconstruction using ipsilateral hamstring tendon autograft and adherence to isokinetic strength testing before and at 5-7 months postoperatively. These patients were then clustered into three groups: EARLY reconstruction (∆ < 42 days), DELAYED reconstruction (∆42-180d), and CHRONIC (∆ > 180d). Knee extensor and flexor strength of the ipsi- and contralateral leg were analyzed by concentric isokinetic measurement (60°/s). Primary outcomes were the maximal knee extension and flexion torque, hamstrings-to-quadriceps ratio (H/Q) ratio), and the corresponding limb symmetry indices.

RESULTS

n = 444 patients met the inclusion criteria. From EARLY to DELAYED to CHRONIC, a progressive reduction in postoperative strength performance was observed in knee extension (1.65 ± 0.45 to 1.62 ± 0.52 to 1.51 ± 0.5 Nm/kg resp.) and flexion (1.22 ± 0.29 to 1.18 ± 0.3 to 1.13 ± 0.31 Nm/kg resp.) strength on the ACL reconstructed leg. This general loss in periarticular strength was already apparent in the preoperative performance even on the healthy side. When controlling for the preoperative performance using ANCOVA analysis, EARLY performed significantly better than DELAYED (extension p = 0.001, flexion p = .02) and CHRONIC (extension p = 0.005, flexion p < 0.001). Also, there were significantly higher values for H/Q ratio in the injured leg across all groups where the H/Q ratio increased from EARLY to CHRONIC and from pre- to postoperative values.

CONCLUSIONS

With respect to the force generating capacity when returning-to-play, it is advantageous to seek for an early ACL reconstruction within the first 12 weeks after the injury. The increasing loss of thigh muscle strength observed in delayed or chronic cases affects the injured and also the non-injured leg.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Assessment of functional prognosis of anterior cruciate ligament reconstruction in athletes based on a body shape index

BACKGROUND

A healthy body shape is essential to maintain athletes’ sports level. At present, little is known about the effect of athletes’ body shape on anterior cruciate ligament reconstruction (ACLR). Moreover, the relationship between body shape and variables such as knee joint function after operation and return to the field has not been well studied.

AIM

To verify the relationship between a body shape index (ABSI) and the functional prognosis of the knee after ACLR in athletes with ACL injuries.

METHODS

We reviewed 76 athletes with unilateral ACL ruptures who underwent ACLR surgery in the First Hospital of Shanxi Medical University between 2017 and 2020, with a follow-up period of more than 24 mo. First, all populations were divided into a High-ABSI group (ABSI > 0.835, n = 38) and a Low-ABSI group (ABSI < 0.835, n = 38) based on the arithmetic median (0.835) of ABSI values. The primary exposure factor was ABSI, and the outcome indicators were knee function scores as well as postoperative complications. The correlation between ABSI and postoperative knee function scores and postoperative complications after ACLR were analyzed using multifactorial logistic regression.

RESULTS

The preoperative knee function scores of the two groups were similar. The surgery and postoperative rehabilitation exercises, range of motion (ROM) compliance rate, Lysholm score, and Knee Injury and Osteoarthritis Outcome Score of the two groups gradually increased, whereas the quadriceps atrophy index gradually decreased. The knee function scores were higher in the Low-ABSI group than in the High-ABSI group at the 24-mo postoperative follow-up (P < 0.05). In multifactorial logistic regression, ABSI was a risk factor of low knee joint function score after surgery, specifically low ROM scores (odds ratio [OR] = 1.31, 95% confidence interval [CI] [1.10-1.44]; P < 0.001), low quadriceps atrophy index (OR = 1.11, 95%CI [0.97-1.29]; P < 0.05), low Lysholm scores (OR = 2.34, 95%CI [1.78-2.94]; P < 0.001), low symptoms (OR = 1.14, 95%CI [1.02-1.34]; P < 0.05), low activity of daily living (OR = 1.34, 95%CI [1.18-1.65]; P < 0.05), low sports (OR = 2.47, 95%CI [1.78-2.84]; P < 0.001), and low quality of life (OR = 3.34, 95%CI [2.88-3.94]; P < 0.001). ABSI was also a risk factor for deep vein thrombosis of the lower limb (OR = 2.14, 95%CI [1.88-2.36], P < 0.05] and ACL recurrent rupture (OR = 1.24, 95%CI [0.98-1.44], P < 0.05) after ACLR.

CONCLUSION

ABSI is a risk factor for the poor prognosis of knee function in ACL athletes after ACLR, and the risk of poor knee function after ACLR, deep vein thrombosis of lower limb, and ACL recurrent rupture gradually increases with the rise of ABSI.

American Academy of Orthopaedic Surgeons Clinical Practice Guideline Summary: Management of Anterior Cruciate Ligament Injuries

Management of Anterior Cruciate Ligament Injuries : Evidence-based Clinical Practice Guideline is based on a systematic review of published studies for the treatment of anterior cruciate ligament injurie in both skeletally mature and immature patients. This guideline contains eight recommendations and seven options to assist orthopaedic surgeons and all qualified physicians managing patients with ACL injuries based on the best current available evidence. It is also intended to serve as an information resource for professional healthcare practitioners and developers of practice guidelines and recommendations. In addition to providing pragmatic practice recommendations, this guideline also highlights gaps in the literature and informs areas for future research and quality measure development.

Subjective Outcomes After Allograft Reconstruction and Nonoperative Treatment of Anterior Cruciate Ligament Ruptures Are Similar in Patients Aged 40 Years and Older: A 2:1 Propensity Score-Matched Analysis

Purpose

To compare subjective outcomes and rates of subsequent operations for patients aged 40 years and older with anterior cruciate ligament (ACL) ruptures who elected nonoperative management or allograft ACL reconstruction (ACLR).

Methods

This was a retrospective study comparing 2-year minimum results of nonoperative treatment and primary allograft ACLR among patients aged 40 years and older presenting to a single institution between the years 2005 and 2016. Patients who elected nonoperative management were 2:1 propensity score (PS)-matched to patients who elected ACLR based on age, sex, body mass index, sports-related mechanism of injury, Outerbridge grade III or IV chondral lesions, and medial or lateral meniscus tears. Univariate analysis was performed to compare subjective outcome measures of International Knee Documentation Committee and Marx activity level scores, subsequent operations, and satisfaction rates.

Results

After 2:1 PS matching, 40 ACLR and 20 nonoperative patients with mean ages of 52.2 years and 54.5 years, respectively, were included with a mean follow-up of 5.7 years (SD 2.1 years, range 2.3-10.6 years). There were no significant differences between the groups in any of the matching variables. There were no significant differences in International Knee Documentation Committee scores (81.9 ± 14.1, CI 77.4-86.5 vs 84.3 ± 12.8, CI 78.3-90.3, P = .53), Marx activity level scores (5.8 ± 4.8, CI 4.2-7.3 vs 5.7 ± 5.1, CI 3.3-8.1, P = .96), or satisfaction rates (100% vs 90%, P = .11) between the ACLR and nonoperative groups. Four (10%) patients who underwent ACLR sustained a graft treated with revision ACLR. 7 (17.5%) ACLR and 0 nonoperative patients subsequently received further ipsilateral knee surgeries (P = .08), including 2 total knee arthroplasties.

Conclusions

In this PS-matched analysis of patients aged 40 years and older with ACL ruptures, patients who elected nonoperative management had similar subjective outcomes compared with those who elected allograft ACLR. Patients who elected allograft ACLR did not have fewer subsequent operations than those who elected nonoperative treatment.

Level of Evidence

Level III, retrospective cohort study.

Previous Isolated Medial Bucket-Handle Meniscus Repair Significantly Increases Risk of Subsequent Ipsilateral Anterior Cruciate Ligament Reconstruction

Purpose

(1) To define the incidence of surgically treated isolated bucket-handle meniscus tears (BHMTs); (2) to investigate risk of subsequent ipsilateral anterior cruciate ligament reconstruction (ACLR) in patients who underwent previous isolated bucket handle (BH) meniscus repair; and (3) to investigate the risk of subsequent ACLR for various types of surgically treated meniscal tears.

Methods

A retrospective review of a national database was conducted to identify patients, aged 10 to 40 years, who underwent primary isolated BH meniscus surgery from 2015 to 2020. Patients were stratified by operative method. A control group of 500,000 age-matched patients was randomly selected to establish a benchmark rate of ACLR. Kaplan-Meier analysis was performed to compare the timing and incidence of subsequent ipsilateral ACLR after primary isolated BH meniscus surgery to the control group within 2 and 5 years.

Results

In total, 1,767 patients with isolated BHMTs treated with surgery were identified and met inclusion criteria. The incidence of isolated BHMTs among all surgically treated (repair or meniscectomy) meniscal injuries was 1.67%. Isolated BH repairs had significantly greater odds of ACLR within 5 years compared to the control group (odds ratio [OR] 6.09; 95% confidence interval [CI] 2.86-12.99; P < .001). Medial BH repairs had the greatest odds of ACLR within 5 years (OR 9.15; 95% CI 4.27-19.57; P < .001). Lateral BH repair was not associated with subsequent ipsilateral ACLR within 5 years (OR 2.63; CI 0.37-18.90; P = .340).

Conclusions

Isolated BHMTs comprised 1.67% of all surgically treated meniscal injuries. Patients who underwent prior surgery for isolated BHMT were at increased risk of undergoing subsequent ipsilateral ACLR compared with the general population. Isolated medial BHMTs treated with repair had the highest risk for subsequent ACLR.

Level of Evidence

Level III, retrospective cohort study.

Analyses of associated factors with concomitant meniscal injury and irreparable meniscal tear at primary anterior cruciate ligament reconstruction in young patients

Purpose

Although several factors related to the concomitant meniscal injury at anterior cruciate ligament reconstruction (ACL-R) have been investigated in a general population, few studies have identified the risk factors of meniscal tear severity in young patients in which the majority of ACL tears occur. The purpose of this study was to analyze the associated factors with meniscal injury and irreparable meniscal tear and the timeline for medial meniscal injury at ACL-R in young patients.

Methods

A retrospective analysis of young patients (13 to 29 years of age) who underwent ACL-R by a single surgeon from 2005 to 2017 was conducted. Predictor variables (age, sex,body mass index [BMI], time from injury to surgery [TS], and pre-injury Tegner activity level) for meniscal injury and irreparable meniscal tear were analyzed with multivariate logistic.

Results

Four hundred and seventy-three consecutive patients with an average of 31.2 months post-operative follow-up were enrolled in this study. The risk factors for medial meniscus injury were TS (<= 3 months) (odds ratio [OR], 3.915; 95% CI, 2.630-5.827; P < .0001) and higher BMI (OR, 1.062; 95% CI, 1.002-1.125; P = 0.0439). The presence of irreparable medial meniscal tears correlated with higher BMI (OR, 1.104; 95% CI, 1.011-1.205; P = 0.0281).

Conclusion

An increased time from ACL tear to surgery of 3 months was strongly associated with an increased risk of medial meniscus injury, but not related to irreparable medial meniscal tear at primary ACL reconstruction in young patients.

Level of Evidence

Level IV.

Increased Time to Surgery After Anterior Cruciate Ligament Tear in Female Patients Results in Greater Risk of Medial Meniscus Tear: A Study of 489 Female Patients

PURPOSE

This study assessed the incidence of meniscal tears in anterior cruciate ligament (ACL)-deficient knees, considering the time between injury and reconstruction in a large sample of female patients. Furthermore, we evaluated whether the rate of meniscal repair or meniscectomy was affected by age and body mass index (BMI).

METHODS

The medical records of 489 patients who underwent ACL-reconstructive surgery between January 2011 and April 2021 were analyzed to collect data on the prevalence of meniscal tears, surgical timing, patient age, and BMI. Logistic regression was performed to estimate the association between the prevalence of meniscal tears and the independent variables of surgical timing, age, and BMI.

RESULTS

Between 24 and 60 months after their injury, female patients showed a statistically significant increase in the presence of associated meniscal lesions when compared with ACL reconstruction performed earlier (odds ratio [OR] of 3.11; 95% 1.06-9.10 confidence interval [CI]), especially for medial meniscal tears, with an OR of 1.94 (95% CI 1.23-3.05, P = .004) between 12 and 24 months. There is a statistically significant difference after 12 months in the rate of meniscal suturing for medial meniscus tears (OR 3.30; CI 1.37-7.91 P = .007). Increasing age was associated with a greater prevalence of meniscal tears up to 30-50 years, but there was no clear association between BMI and associated lesions other than a greater rate of meniscectomies.

CONCLUSIONS

In female patients who experienced an ACL injury, a delay in surgery greater than 12 months is associated with a gradual increase in the risk of nonrepairable medial meniscal tear; this risk becomes statistically significant after 24 months. A high BMI does not seem to have relevance in the onset of associated lesions in women but results in a greater rate of meniscectomies compared with meniscal sutures, whereas age between 30 and 50 years is associated with a greater risk of associated injuries.

LEVEL OF EVIDENCE

III, retrospective comparative prognostic trial.

The hydroxyapatite modified 3D printed poly L-lactic acid porous screw in reconstruction of anterior cruciate ligament of rabbit knee joint: a histological and biomechanical study

BACKGROUND

3D printing technology has become a research hotspot in the field of scientific research because of its personalized customization, maneuverability and the ability to achieve multiple material fabrications. The focus of this study is to use 3D printing technology to customize personalized poly L-lactic acid (PLLA) porous screws in orthopedic plants and to explore its effect on tendon-bone healing after anterior cruciate ligament (ACL) reconstruction.

METHODS

Preparation of PLLA porous screws with good orthogonal pore structure by 3D printer. The hydroxyapatite (HA) was adsorbed on porous screws by electrostatic layer-by-layer self-assembly (ELSA) technology, and PLLA-HA porous screws were prepared. The surface and spatial morphology of the modified screws were observed by scanning electron microscopy (SEM). The porosity of porous screw was measured by liquid displacement method. Thirty New Zealand male white rabbits were divided into two groups according to simple randomization. Autologous tendon was used for right ACL reconstruction, and porous screws were inserted into the femoral tunnel to fix the transplanted tendon. PLLA group was fixed with porous screws, PLLA-HA group was fixed with HA modified porous screws. At 6 weeks and 12 weeks after surgery, 5 animals in each group were sacrificed randomly for histological examination. The remaining 5 animals in each group underwent Micro-CT and biomechanical tests.

RESULTS

The pores of PLLA porous screws prepared by 3D printer were uniformly distributed and connected with each other, which meet the experimental requirements. HA was evenly distributed in the porous screw by ELSA technique. Histology showed that compared with PLLA group, mature bone trabeculae were integrated with grafted tendons in PLLA-HA group. Micro-CT showed that the bone formation index of PLLA-HA group was better than that of PLLA group. The new bone was uniformly distributed in the bone tunnel along the screw channel. Biomechanical experiments showed that the failure load and stiffness of PLLA-HA group were significantly higher than those of PLLA group.

CONCLUSIONS

The 3D printed PLLA porous screw modified by HA can not only fix the grafted tendons, but also increase the inductivity of bone, promote bone growth in the bone tunnel and promote bone integration at the tendon-bone interface. The PLLA-HA porous screw is likely to be used in clinic in the future.

Low reoperation rate following lateral meniscus root repair: clinical outcomes at 2 years follow-up

PURPOSE

The aim of this study was to review the outcomes of lateral meniscus posterior root tears repair at the time of ACL reconstruction at a minimum 2-year follow-up.

METHODS

Between March 2015 and August 2018, 2017 patients underwent primary ACL reconstruction and were considered for study eligibility. Lateral meniscus posterior root tears were identified arthroscopically, and repair was performed with a transtibial pull-out suture technique or a side-to-side suture technique. Clinical outcomes were recorded at the time of physical examination. At the end of the study period, patients were contacted to determine whether they had required reoperation.

RESULTS

Lateral meniscus posterior root tears were identified in 153 out of the 2,017 primary ACL reconstructions (7.6%). Ninety-nine patients were included for analysis: 23 transtibial pull-out sutures and 76 side-to-side repairs. At a mean follow-up of 42 ± 10 months, one patient (1%) had undergone reoperation for failure of the side-to-side repair. There were 11 reoperations in 10 patients (10.1%), including 6 cyclops syndrome, 1 graft rupture, 1 tibial bone cyst, 1 medial and 1 lateral meniscus repair failure, and 1 arthrolysis. Postoperatively, ninety (90.9%) patients were graded A for the IKDC objective score and 9 (9.1%) patients were graded B, with an IKDC subjective score of 86.9 ± 7.6, a Lysholm score of 90.7 ± 6.7 and a median Tegner Activity Scale of 6 (3-9). All of their objective and subjective evaluations improved after surgery (p < 0.001) except for the Tegner Activity Scale. Ten patients underwent second look arthroscopy (10.1%), lateral meniscus healing was observed in 9 out of 10 patients (90%).

CONCLUSION

This study demonstrated that lateral meniscus posterior root tear repair is a safe procedure with a very low reoperation rate at a minimum follow-up of 2 years.

LEVEL OF EVIDENCE

IV.

Risk factors for secondary meniscus tears can be accurately predicted through machine learning, creating a resource for patient education and intervention

PURPOSE

This study sought to develop and internally validate a machine learning model to identify risk factors and quantify overall risk of secondary meniscus injury in a longitudinal cohort after primary ACL reconstruction (ACLR).

METHODS

Patients with new ACL injury between 1990 and 2016 with minimum 2-year follow-up were identified. Records were extensively reviewed to extract demographic, treatment, and diagnosis of new meniscus injury following ACLR. Four candidate machine learning algorithms were evaluated to predict secondary meniscus tears. Performance was assessed through discrimination using area under the receiver operating characteristics curve (AUROC), calibration, and decision curve analysis; interpretability was enhanced utilizing global variable importance plots and partial dependence curves.

RESULTS

A total of 1187 patients underwent ACLR; 139 (11.7%) experienced a secondary meniscus tear at a mean time of 65 months post-op. The best performing model for predicting secondary meniscus tear was the random forest (AUROC = 0.790, 95% CI: 0.785-0.795; calibration intercept = 0.006, 95% CI: 0.005-0.007, calibration slope = 0.961 95% CI: 0.956-0.965, Brier's score = 0.10 95% CI: 0.09-0.12), and all four machine learning algorithms outperformed traditional logistic regression. The following risk factors were identified: shorter time to return to sport (RTS), lower VAS at injury, increased time from injury to surgery, older age at injury, and proximal ACL tear.

CONCLUSION

Machine learning models outperformed traditional prediction models and identified multiple risk factors for secondary meniscus tears after ACLR. Following careful external validation, these models can be deployed to provide real-time quantifiable risk for counseling and timely intervention to help guide patient expectations and possibly improve clinical outcomes.

LEVEL OF EVIDENCE

III.

Effect of Delayed Anterior Cruciate Ligament Reconstruction on Repair of Concomitant Medial Meniscus Tears in Young Athletes

BACKGROUND

Delayed anterior cruciate ligament (ACL) reconstruction (ACLR) is associated with an increased risk of meniscal injury. Limited data are available regarding the relationship between surgical delay and meniscal repairability in the setting of ACLR in young patients.

PURPOSE

To determine whether time from ACL injury to primary ACLR was associated with the incidence of medial and/or lateral meniscal repair in young athletes who underwent meniscal treatment at the time of ACLR.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Records were retrospectively reviewed for patients aged 13 to 25 years who underwent primary ACLR between January 2017 and June 2020 by surgeons from a single academic orthopaedic surgery department. Demographic data were collected, and operative reports were reviewed to document all concomitant pathologies and procedures. Univariable and multivariable logistic regression analyses were used to determine factors associated with meniscal repair, including time elapsed from ACL injury to surgery.

RESULTS

Concomitant meniscal tears were identified and treated in 243 of 427 patients; their mean age was 17.9 ± 3.3 years, and approximately half (47.7%) of patients were female. There were 144 (59.3%) medial tears treated and 164 (67.5%) lateral tears treated; 65 (26.7%) patients had both medial and lateral tears treated. Median time from ACL injury to ACLR was 2.4 months (interquartile range, 1.4-4.7 months). Adjusted univariate analysis showed a statistically significant correlation between medial meniscal repair and time to surgery, with a 7% decreased incidence of medial meniscal repair per month elapsed between injury and surgery (odds ratio, 0.93 per month; 95% CI, 0.89-0.98; P = .006). No similar relationship was found between lateral meniscal repair and time to surgery (odds ratio, 1.02; 95% CI, 0.99-1.06; P = .24).

CONCLUSION

In the setting of concomitant ACL and meniscal injuries, surgical delay decreased the incidence of medial meniscal repair in young athletes by 7% per month from time of injury.

Patients With Anterior Cruciate Ligament Rupture and Ipsilateral Segond Fractures Have High Rates of Concurrent Knee Pathology

Purpose

The purpose of this study was to determine the rates of concomitant knee pathology in patients with ACL injuries and Segond fractures.

Methods

A retrospective study is undertaken with patients identified via query of CPT codes for ACL reconstruction from 2014 to 2020. All patients with preoperative radiographs were reviewed for the presence of Segond fractures. Operative reports were analyzed for the presence of concurrent pathology, including meniscus, cartilage, and other ligamentous injuries at the time of arthroscopic ACL reconstruction.

Results

A total of 1,058 patients were included in the study. Segond fractures were identified in 50 (4.7%) patients. Ipsilateral concomitant knee pathology was identified in 84% of Segond patients. Thirty-eight (76%) patients had meniscal pathology with a total 49 meniscal injuries, of which 43 were treated operatively. Multiligamentous injuries were present in 16 patients (32%), with 8 patients undergoing further ligament repair/reconstruction at the time of surgery. Chondral injuries were identified in 13 patients (26%).

Conclusions

A high prevalence of concomitant meniscal, chondral, and ligamentous injuries was found in patients with Segond fractures. These additional injuries may require further operative management and may place patients at increased risk for future instability or degenerative changes. Patients with Segond fractures should be counseled preoperatively on the nature of their injuries and risk of associated pathologies.

Level of Evidence

Level IV, prognostic case series.

Age, Sex, and BMI Differences Related to Repairable Meniscal Tears in Pediatric and Adolescent Patients

BACKGROUND

The incidence of meniscus tears and ACL tears in pediatric patients continues to rise, bringing to question the risk factors associated with these injuries. As meniscus tears are commonly repaired in pediatric populations, the epidemiology of repairable meniscus tears is an important for consideration for surgeons evaluating treatment options.

PURPOSE

To describe meniscal tear patterns in pediatric and adolescent patients who underwent meniscal repair across multiple institutions and surgeons, as well as to evaluate the relationship between age, sex, and body mass index (BMI) and their effect on the prevalence, type, and displacement of repaired pediatric meniscal tears.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Data within a prospective multicenter cohort registry for quality improvement, Sport Cohort Outcome Registry (SCORE), were reviewed to describe repaired meniscal tear patterns. All consecutive arthroscopic meniscal repairs from participating surgeons in patients aged <19 years were analyzed. Tear pattern, location, and displacement were evaluated by patient age, sex, and BMI. A subanalysis was also performed to investigate whether meniscal tear patterns differed between those occurring in isolation or those occurring with a concomitant anterior cruciate ligament (ACL) injury. Analysis of variance was used to generate a multivariate analysis of specified variables. Sex, age, and BMI results were compared across the cohort.

RESULTS

There were 1185 total meniscal repairs evaluated in as many patients, which included 656 (55.4%) male and 529 (44.6%) female patients. Patients underwent surgery at a mean age of 15.3 years (range, 5-19 years), with a mean BMI of 24.9 (range, 12.3-46.42). Of the 1185 patients, 816 (68.9%) had ACL + meniscal repair and 369 (31.1%) had isolated meniscal repair. The male patients underwent more lateral tear repairs than the female patients (54.3% to 40.9%; P < .001) and had a lower incidence of medial tear repair (32.1% vs 41.4%; P < .001). Patients with repaired lateral tears had a mean age of 15.0 years, compared with a mean age of 15.4 years for patients with repaired medial or bilateral tears (P = .001). Higher BMI was associated with "complex" and "radial" tear repairs of the lateral meniscus (P < .001) but was variable with regard to medial tear repairs.

CONCLUSION

In pediatric and adolescent populations, the data suggest that the surgical team treating knees with potential meniscal injury should be prepared to encounter more complex meniscal tears, commonly indicated in those with higher BMI, while higher rates of lateral meniscal tears were seen in male and younger patients. Future studies should analyze correlates for meniscal repair survival and outcomes in this pediatric cohort undergoing knee surgery.

Incidence and type of meniscal tears in multilligament injured knees

PURPOSE

Meniscal injuries occurring during multi-ligament knee injuries (MLKI) are underreported. The purpose of this study was to compare the incidence and type of meniscal tears seen at the time of multi-ligament reconstruction surgery compared to those occurring during isolated anterior cruciate ligament (ACL) surgery.

METHODS

Patients undergoing surgical treatment for MLKI and ACL-only injuries between 2010 and 2020 were reviewed. Two-hundred and thirty-five patients were included in the MLKI group. There were 131 chronic injuries and 104 acute injuries. Two-hundred and twenty-two ACL-only chronic injuries were used as a control group for comparison with the chronic MLKI group. Demographic data, type of meniscal tears, ligament injury patterns (Schenck classification) and time from injury to surgery were recorded. A delayed procedure was defined by a 4-week interval after the knee injury.

RESULTS

A meniscus was torn in 69 knees (29.4%): 36 knees (15.3%) with an isolated medial meniscus tear, 33 knees (17.9%) with an isolated lateral meniscus tear,.Nine knees (3.8%) had both menisci torn. MLKI with medial or lateral-sided bicruciate ligament injuries (KDIIIM-KDIIIL) were significantly associated with a lower rate of meniscal tears than knee injuries involving the ACL-only and medial/lateral-sided ligament injuries (KDI) (medial-sided injuries p = 0.025; lateral-sided injuries p = 0.049). Lateral-sided injuries had significantly less meniscal damage than medial-sided injuries: 22/124 (17.7%) vs. 41/100 (41%); (p < 0.001). No significant differences were found for frequency, type and distribution of meniscal tears between acute and chronic MLKI surgery. ACL-only chronic injuries were associated with a higher rate of meniscal tears: 123/222 knees (55.4%) vs. 35/131 (26.9%) chronic MLKI; (p < 0.001), mainly involving the medial meniscus: 102/222 (46%) vs. 18/131 (13.7%); (p < 0.001).

CONCLUSIONS

Meniscal tears were less common in the MLKI group than in the isolated ACL injury group. The degree of ligament injury patterns and the side of the injured collateral ligament influenced the type and incidence of meniscal damage. Contrary to isolated ACL injuries, a delayed procedure was not associated with a higher rate of meniscal lesions but did influence the type of treatment. Understanding of meniscal tears patterns in MLKI helps to improve the treatment management of these complex injuries.

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.

Revision Soft-Tissue Allograft Anterior Cruciate Ligament Reconstruction Is Associated With Lower Patient-Reported Outcomes Compared With Primary Anterior Cruciate Ligament Reconstruction in Patients Aged 40 and Older

PURPOSE

To evaluate patient-reported outcomes (PROs) and graft failure rates in revision allograft anterior cruciate ligament reconstruction (ACLR) in patients aged 40 and older and compare them with primary ACLRs.

METHODS

Patients aged 40 and older who underwent arthroscopic soft-tissue allograft ACLR between 2005 and 2016 with a minimum 2-year follow-up were retrospectively reviewed. Patients were grouped based on revision versus primary ACLR. The rate of achieving an International Knee Documentation Committee (IKDC) patient acceptable symptom state (PASS) score was recorded. Patient satisfaction, PROs, and graft failure were compared between groups using the χ² test, Fisher exact test, and Mann-Whitney U test.

RESULTS

We identified 32 patients who underwent revision ACLR and 201 patients who underwent primary ACLR aged 40 and older who met inclusion criteria with a mean follow-up of 6.2 and 6.9 years, respectively (P = .042). There was a lower rate of concomitant meniscal repair in the primary ACLR group (6% vs 21.9%, P = .007) There were no other differences in chondral injuries, mechanism of injury, or meniscal injuries between groups. The median IKDC score was greater in the primary ACLR group as compared with the revision ACLR group (83.9 vs 70.6, P < .001). Patients who underwent revision ACLR were less likely to achieve the IKDC PASS threshold (82.5% vs 56.3%, P = .001) and were less likely to report satisfaction as compared with patients who underwent primary ACLR (90.5% vs 78.1%, P =.038). No difference in graft failure rates was identified between groups (8% vs 15.6%, P = .180).

CONCLUSIONS

Revision allograft ACLR in patients aged 40 and older was associated with lower PROs compared with primary ACLR. Patients who underwent revision ACLR failed to meet the IKDC PASS threshold more often and were dissatisfied with procedure results more than twice as often as patients that underwent primary ACLR.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Short term clinical outcomes of a Prochondrix® thin laser-etched osteochondral allograft for the treatment of articular cartilage defects in the knee

Objective: The purpose of this study is to evaluate the short-term clinical outcomes of Prochondrix® novel thin, laser-etched osteochondral allograft on isolated articular cartilage defects. Methods: Eighteen patients with isolated, symptomatic, full-thickness articular cartilage lesions were treated with marrow stimulation followed by placement of a T-LE allograft. Demographic and intra-operative data was recorded as well as pre- and post-operative International Knee Documentation Committee (IKDC), Short Form-36 (SF-36), Knee Injury and Osteoarthritis Outcome Score (KOOS), Visual Analogue Scale (VAS) and Tegner scores. Pre- and post-operative data was compared at 6, 12, 24 and 36 months post operatively. Failures requiring reoperation were also recorded. Results: At a mean follow-up of 2.5 years (6-43 months), VAS decreased from 6.55 to 2.55 (p = .02) and subjective IKDC scores increased from 37.61 to 59.65 (p = .02). Statistically significant increases were also seen in KOOS Function-Sports and Recreational Activities (+26.04, p = .04) and KOOS QOL (+18.76, p = .007) as well as in SF-36 Physical Functioning (+25.20, p = .04), Energy/Fatigue (+16.50, p = .02), Social Functioning (+11.79, p = .04), and Bodily Pain (+25.18, p = .04). There were two failures requiring reoperation: one conversion to a patellofemoral arthroplasty (PFA), and one graft dislodgement which required removal. Conclusion: Treatment of articular cartilage lesions of the knee with ProChondrix® has demonstrated sustained positive results out to a mean follow-up of two and a half years in this prospective case series with a low failure rate that required reoperation (2 patients) in this series. These results are comparable to the short-term results of other cartilage restoration procedures currently in use today. A meta-analysis of osteochondral allografting demonstrated a mean 86.7% survival rate at 5 years with significant improvements in clinical outcome scores reaching MCID values.

Anterior cruciate ligament rupture and associated Segond fracture: Incidence and effect on associated ligamentous and meniscal injuries

Introduction

The Segond fracture is an avulsion fracture of the lateral tibial plateau and is widely considered to be pathognomonic of anterior cruciate ligament (ACL) rupture. In addition to ACL rupture, Segond fractures have also been noted to be associated with significant intra-articular pathology such as meniscal injuries as well as extra-articular pathology such as collateral ligament injuries. This is likely due to the fact that the presence of a Segond fracture may represent increased rotatory instability. Whilst several studies have demonstrated the association of a Segond fracture with significant intra-articular pathology, there is a paucity of literature assessing if the combination of an ACL rupture and Segond fracture gives rise to higher rates of concomitant ligamentous and meniscal injuries. The primary objective of this study is to determine if patients with ACL ruptures associated with Segond fractures have higher rates of concomitant ligamentous and meniscal injury, when compared to patients with ACL ruptures without a Segond fracture.

Methods

A retrospective review of all patients who underwent ACL reconstruction in a single institution between 2014 to 2018 was conducted. A review of the patients’ demographics, operative notes, and radiographs was performed. X-rays and MRI scans were double-read by a board-certified radiologist and Orthopaedic surgeon.

Results

A total of 414 subjects were included. The incidence of Segond fracture was 2.4%. The mean age was 24.7±7.4 (range 16 to 60) years and 26.7±7.6 (range 16 to 38) years in patients with and without Segond fractures respectively. 89.9% of patients suffered a non-contact mechanism of injury, with sports injuries being most common (79.5%). There was a significantly higher rate of isolated lateral meniscus tears in patients with Segond fractures compared to those without (50% v.s. 20.8%) based on pre-operative MRI. (p<0.05) There were no other significant differences in associated ligamentous injuries.

Conclusion

The incidence of Segond fracture associated with ACL rupture is 2.4%. There is a significantly higher risk of a concomitant isolated lateral meniscus tear in ACL ruptures associated with a Segond fracture. There is no significantly higher risk of concomitant ligamentous injuries in ACL ruptures associated with a Segond fracture.

Acute and subacute anterior cruciate ligament reconstructions are associated with a higher risk of revision and reoperation

PURPOSE

(1) Report concomitant cartilage and meniscal injury at the time of anterior cruciate ligament reconstruction (ACLR), (2) evaluate the risk of aseptic revision ACLR during follow-up, and (3) evaluate the risk of aseptic ipsilateral reoperation during follow-up.

METHODS

Using a United States integrated healthcare system's ACLR registry, patients who underwent primary isolated ACLR were identified (2010-2018). Multivariable Cox proportional-hazards regression was used to evaluate the risk of aseptic revision, with a secondary outcome evaluating ipsilateral aseptic reoperation. Outcomes were evaluated by time from injury to ACLR: acute (< 3 weeks), subacute (3 weeks-3 months), delayed (3-9 months), and chronic (≥ 9 months).

RESULTS

The final sample included 270 acute (< 3 weeks), 5971 subacute (3 weeks-3 months), 5959 delayed (3-9 months), and 3595 chronic (≥ 9 months) ACLR. Medial meniscus [55.4% (1990/3595 chronic) vs 38.9% (105/270 acute)] and chondral injuries [40.0% (1437/3595 chronic) vs 24.8% (67/270 acute)] at the time of ACLR were more common in the chronic versus acute groups. The crude 6-year revision rate was 12.9% for acute ACLR, 7.0% for subacute, 5.1% for delayed, and 4.4% for chronic ACLR; reoperation rates a 6-year follow-up was 15.0% for acute ACLR, 9.6% for subacute, 6.4% for delayed, and 8.1% for chronic ACLR. After adjustment for covariates, acute and subacute ACLR had higher risks for aseptic revision (acute HR 1.70, 95% CI 1.07-2.72, p = 0.026; subacute HR 1.25, 95% CI 1.01-1.55, p = 0.040) and aseptic reoperation (acute HR 2.04, 95% CI 1.43-2.91, p < 0.001; subacute HR 1.31, 95% CI 1.11-1.54, p = 0.002) when compared to chronic ACLR.

CONCLUSIONS

In this cohort study, while more meniscal and chondral injuries were reported for ACLR performed ≥ 9 months after the date of injury, a lower risk of revision and reoperation was observed following chronic ACLR relative to patients undergoing surgery in acute or subacute fashions.

Risk of reoperation after primary anterior cruciate ligament reconstruction in children and adolescents

OBJECTIVE

To examine the incidence and risk factors of any-cause reoperation after primary ACLR in children and adolescents.

DESIGN

Retrospective Cohort.

SETTING

Electronic medical records from a large tertiary care, single institution integrated healthcare delivery system.

PATIENTS

Patients were under the age of 18 years and had anterior cruciate ligament reconstruction. They were excluded if they had a multi-ligamentous knee injury or <1 year follow-up.

INTERVENTIONS

Patients were further identified to have undergone a subsequent knee operation ipsilaterally or contralateral ACLR.

MAIN OUTCOME MEASURES

The rate of any-cause reoperation was our primary outcome measure.

RESULTS

The median age was 16. There were 208 females (53.9%) and 178 males (46.1%) included. The median follow-up was 25 months with a minimum of 12 months (interquartile range: 16.0, 46.0). The rate of any-cause reoperation was 34.7%. There was no statistically significant difference between those who underwent reoperation versus those who did not undergo reoperation relative to age, sex, BMI, graft type, or the presence of concomitant meniscal injury. The rates of ipsilateral ACLR and contralateral ACLR at any time during the study period was 8.0% and 10.9% respectively. There was no statistically significant difference for rate of reoperation between graft types, between various concomitant injuries, between those who underwent meniscus repair or no repair.

CONCLUSIONS

This study reflects a 34.7% rate of a subsequent knee operation after ACLR in patients younger than 18 years. These findings can be used to inform pediatric patients undergoing primary ACLR on their risk of returning to the operating room.

Time from Injury Is the Key Predictor of Meniscal Injury in ACL-Deficient Knees

The meniscus is one of the most important structures of the knee that needs to be saved if possible. Previous studies showed that increasing time from an anterior cruciate ligament (ACL) injury (TFI) could lead to a meniscal tear, especially medial meniscus (MM). We developed the present study to see if the TFI alone is a predictor of meniscal injury in ACL-deficient knees. We included 111 patients who had a reconstructed ACL injury at our institution from March 2015 to March 2016 in this retrospective cohort study. All demographic data, including age, gender, and body mass index (BMI), were collected. We also recorded the mechanism of injury and the TFI. We extracted the meniscal condition at the time of surgery from the surgical report. All patients were followed up for a mean of 23 months, and the Lysholm score and pain visual analog scale (VAS) score were obtained. The mean TFI of patients with MM tear was 17.4 ± 16.8 months, which was significant than the patients with lateral meniscal (LM) tear (9.3 ± 8.3 months) and intact meniscus (7.4 ± 8.1 months) (p = 0.001). Patients with TFI less than 6 months had a significantly lower rate of MM tear, and increasing TFI more than 6 months could increase the rate of MM tear (p = 0.001). We could not find any association between age, BMI, and gender and meniscal injury. At the latest follow-up, Lysholm and VAS scores in patients with and without meniscal tear were the same. Our study confirms that increasing time from the ACL injury would increase the risk of MM damage. The cutoff point for this risk factor is 6 months from initial injury; therefore, to save the meniscus, it might be better to perform ACL reconstruction within 6 months in ACL-deficient knees.

Total Knee Arthroplasty after Anterior Cruciate Ligament Reconstruction

The incidence of anterior cruciate ligament (ACL) reconstruction is increasing in the United States, particularly in the older athlete. Patients who undergo ACL reconstruction are at higher risk for undergoing total knee arthroplasty (TKA) later in life. TKA in patients with prior ACL reconstruction has been associated with longer operative time due in-part to difficulty with exposure and retained hardware. Outcomes after TKA in patients with prior ACL reconstruction are not well defined, with some reports showing increased rate of complications and higher risk of reoperation compared with routine primary TKA, but these results are based on small and nonrandomized cohorts. Future research is needed to determine whether graft choice or fixation technique for ACL reconstruction influences outcomes after subsequent TKA. Furthermore, whether outcomes are affected by choice of TKA implant design for patients with prior ACL reconstruction warrants further study. This review analyzes the epidemiology, operative considerations, and outcomes of TKA following ACL reconstruction.

Shear strain and inflammation-induced fixed charge density loss in the knee joint cartilage following ACL injury and reconstruction: A computational study

Excessive tissue deformation near cartilage lesions and acute inflammation within the knee joint after anterior cruciate ligament (ACL) rupture and reconstruction surgery accelerate the loss of fixed charge density (FCD) and subsequent cartilage tissue degeneration. Here, we show how biomechanical and biochemical degradation pathways can predict FCD loss using a patient-specific finite element model of an ACL reconstructed knee joint exhibiting a chondral lesion. Biomechanical degradation was based on the excessive maximum shear strains that may result in cell apoptosis, while biochemical degradation was driven by the diffusion of pro-inflammatory cytokines. We found that the biomechanical model was able to predict substantial localized FCD loss near the lesion and on the medial areas of the lateral tibial cartilage. In turn, the biochemical model predicted FCD loss all around the lesion and at intact areas; the highest FCD loss was at the cartilage-synovial fluid-interface and decreased toward the deeper zones. Interestingly, simulating a downturn of an acute inflammatory response by reducing the cytokine concentration exponentially over time in synovial fluid led to a partial recovery of FCD content in the cartilage. Our novel numerical approach suggests that in vivo FCD loss can be estimated in injured cartilage following ACL injury and reconstruction. Our novel modeling platform can benefit the prediction of PTOA progression and the development of treatment interventions such as disease-modifying drug testing and rehabilitation strategies.

The Majority of Patients Aged 40 and Older Having Allograft Anterior Cruciate Ligament Reconstruction Achieve a Patient Acceptable Symptomatic State

PURPOSE

To evaluate patient satisfaction, retear rates, and patient-reported outcomes (PROs) in patients aged 40 and older undergoing allograft anterior cruciate ligament reconstruction (ACLR). The secondary goal was to compare these parameters between groups of patients with intact versus failed grafts, and to evaluate these in relation to a historically reported International Knee Documentation Committee (IKDC) patient-acceptable symptoms state (PASS) score.

METHODS

Records of patients aged 40 and older who underwent ACLR between 2005 and 2016 at a single institution with a minimum 2-year follow-up were retrospectively reviewed. Patient-reported satisfaction, outcome scores, and failure rates were analyzed. The rate of achieving a previously defined IKDC PASS score based on younger cohorts was reported, and an updated PASS threshold for older patients was calculated.

RESULTS

201 patients were included with a mean age of 48.6 years (range: 40-68) and mean follow-up of 6.2 years (range: 2.8-11.2). 182 (90.5%) patients reported satisfaction following surgery. 16 (8.0%) patients experienced failure of their ACLR, 10 of which underwent revision ACLR. The median IKDC score in the intact ACLR group was 86.2, compared to 66.7 in the failure group (P < .001). In total, 134 (72.4%) patients in the intact group achieved the historical PASS score of 75.9 on IKDC compared to only 4 (25%) in the failure group (χ² = 15.396, P < .001). An updated IKDC PASS threshold for older cohorts was calculated to be 66.7.

CONCLUSION

Patients aged 40 and older who underwent allograft ACLR had an 8.0% failure rate at a mean follow-up of 6 years. Graft failure in patients aged 40 and older was associated with worse PROs. The majority of patients achieved the historically reported IKDC PASS threshold. Additionally, an updated age-appropriate IKDC PASS score of 66.7 was calculated to aid in future ACLR studies assessing older patients.

STUDY DESIGN

Level IV.

A larger side-to-side difference in anterior knee laxity increases the prevalence of medial and lateral meniscal injuries in patients with ACL injuries

PURPOSE

The objective of this study was to investigate factors that influence the prevalence of medial and lateral meniscal injuries at the time of anterior cruciate ligament (ACL) reconstruction in patients with ACL injuries.

METHODS

Patients with ACL injuries at 9 institutions were enrolled in this multicentre study. Age, sex, duration between injury and surgery, pivot shift test grade, anterior knee laxity determined using the Kneelax 3 arthrometer, and other variables were assessed by logistic regression analysis. Meniscal conditions were evaluated via arthroscopy.

RESULTS

In all, 830 patients were enrolled. The prevalence of medial and lateral meniscal tears was 32.0% (266 knees) and 26.5% (220 knees), respectively. Significant factors that influenced the prevalence of medial meniscal injuries were age [odds ratio (OR) 1.03; P = 0.000], side-to-side differences in instrumented anterior knee laxity before surgery (OR 1.12; P = 0.002), duration between injury and surgery (≥ 12 months) (OR 1.86; P = 0.023), and pivot shift test grade (OR 1.36; P = 0.014). Significant factors of lateral meniscal injury were side-to-side differences in anterior knee laxity before surgery (OR 1.12; P = 0.003) and the male sex (OR 1.50; P = 0.027).

CONCLUSION

Greater anterior knee laxity, age, a longer duration between injury and surgery, and a higher pivot shift test grade predicted medial meniscal injury. Greater anterior knee laxity and the male sex predicted lateral meniscal injury. In patients with ACL injuries, the importance of side-to-side differences in anterior knee laxity should be rediscovered from the viewpoint of meniscal conditions.

LEVEL OF EVIDENCE

Level III.

Demographic Factors Associated With an Increased Incidence of Intra-articular Injuries After Delayed Anterior Cruciate Ligament Reconstruction

Background:

Delays from the time of an anterior cruciate ligament (ACL) tear to surgical reconstruction are associated with an increased incidence of meniscal and chondral injuries.

Purpose:

To evaluate the association between delays in ACL reconstruction (ACLR) and risk factors for intra-articular injuries across 8 patient demographic subsets.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

We performed a retrospective chart review of all patients who underwent ACLR from January 2009 to May 2015 at a single institution. Variables collected were age, sex, body mass index, time from injury to surgery, and presence of meniscal tears and chondral injuries. Demographic subsets were created according to sex, age (<27 vs ≥27 years), body mass index (<25 vs ≥25 kg/m²), and injury setting (sports vs non–sports related). Subsets were divided by time from injury to ACLR: 0 to <6 months (control group), 6 to <12 months, and ≥12 months. Multivariate logistic regression–generated odds ratios (ORs) were calculated.

Results:

Overall, 410 patients were included. ORs were significant for an increased incidence of medial meniscal tears (MMTs) (OR, 1.12-3.72; P = .02), medial femoral condyle (MFC) injuries (OR, 1.18-4.81; P = .02), and medial tibial plateau (MTP) injuries (OR, 1.33-31.07; P = .02) with surgical delays of 6 to <12 months. With ≥12-month delays, significance was found for MMTs (OR, 2.92-8.64; P < .001), MFC injuries (OR, 1.86-5.88; P < .001), MTP injuries (OR, 1.37-21.22; P = .02), lateral femoral condyle injuries (OR, 2.41-14.94; P < .001), and lateral tibial plateau injuries (OR, 1.15-5.27; P = .02). In the subset analysis, differences in the timing, location, rate, and pattern of chondral and meniscal injuries became evident. Female patients and patients with non–sports-related ACL tears had less risk of associated injuries with delayed surgery, while other demographic groups showed an increased injury risk.

Conclusion:

When analyzing patients who were symptomatic enough to eventually require surgery, an increased incidence of MMTs and medial chondral injuries was associated with ≥6-month delays in ACLR, and an increased incidence of lateral chondral injuries was associated with ≥12-month delays. Female patients and patients with non–sports-related ACL tears had less risk of injuries with delayed ACLR.