Ten-Year Outcomes and Risk Factors After Anterior Cruciate Ligament Reconstruction: A MOON Longitudinal Prospective Cohort Study

International Knee Documentation Committee Subjective Knee Form Latent Growth Model Analysis: Assessing Recovery Trajectories

Patient-Reported Outcome Measures (PROMs), such as the six-item International Knee Documentation Committee Subjective Knee Form (IKDC-6), play a crucial role in assessing health conditions and guiding clinical decisions. Latent Growth Modeling (LGM) can be employed to understand recovery trajectories in patients post-operatively. Therefore, the purpose of this study was to assess LGM properties of the IKDC-6 in patients with knee pathologies that require surgical intervention and to assess differences between subgroups (i.e., sex and age). A cross-sectional study was conducted using the Surgical Outcome System (SOS) database with patients who had undergone knee arthroscopy. Our results found that preoperative scores did not influence the rate of change overtime. Perceived knee health improved over time, with varying rates among individuals. The adolescent age subgroup and male subgroup exhibited faster recovery rates compared to the older age subgroup and female subgroup. While initial hypotheses suggested IKDC-6 could serve as a prognostic tool, results did not support this. However, results indicated favorable outcomes irrespective of preoperative perceived knee impairment levels. This study provides valuable insights into recovery dynamics following knee surgery, emphasizing the need for personalized rehabilitation strategies tailored to individual patient characteristics.

Anterior-Posterior Center of Pressure Is Associated With Knee Extensor Moment During Landing After Anterior Cruciate Ligament Reconstruction

CONTEXT

A reduced knee extensor moment (KEM) in the involved limb and asymmetry in the KEM during landing tasks are observed after anterior cruciate ligament reconstruction (ACLR). There is limited information about the association of kinetic and kinematic parameters with the KEM during landing after ACLR. This study investigated the association of the anterior-posterior center of pressure (AP-COP) position, vertical ground reaction force (VGRF), and lower limb joint angles with the KEM during landing in female athletes following ACLR.

DESIGN

Cross-sectional study.

METHODS

Twenty-two female athletes who underwent ACLR performed a drop vertical jump at 7.9 (1.7) months after surgery. We evaluated the KEM, AP-COP position, VGRF, and sagittal plane hip, knee, and ankle angles using a 3-dimensional motion analysis system with force plates.

RESULTS

The peak KEM in the involved limb was significantly smaller than that in the uninvolved limb during landing (1.43 [0.33] N·m/kg/m vs 1.84 [0.41] Nm/kg/m, P = .001). The VGRF in the involved limb was significantly smaller than that in the uninvolved limb (11.9 [2.3] N/kg vs 14.6 [3.5] N/kg, P = .005). The limb symmetry index of the KEM was predicted by that of the VGRF (P < .001, R2 = .621, β = 0.800). The KEM was predicted by the AP-COP position in the involved limb (P = .015, R2 = .227, β = 0.513) and by the VGRF in the uninvolved limb (P = .018, R2 = .213, β = 0.500). No significant correlation was noted between the KEM and the lower limb joint angles.

CONCLUSIONS

The AP-COP position and VGRF were associated with the KEM during landing. Evaluating the VGRF and AP-COP position, not the lower limb joint angles, may contribute to understanding the KEM during double-leg landing after ACLR in the clinical setting.

Satisfactory 5-year functional outcomes following primary ACL reconstructions from the UK National Ligament Registry

PURPOSE

The aim of this study was to describe the 10-year findings from the UK National Ligament Registry (NLR).

METHODS

A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary ACL reconstruction (ACLR) on the registry were included. Surgical characteristics were analysed, including surgeon grade and case volume, concomitant knee procedures, venous thromboembolic prophylaxis, graft characteristics, femoral and tibial tunnel drilling, and fixation methods. Clinical outcomes were collected preoperatively and at 6 months, 1 year, 2 years and 5 years following the index procedure.

RESULTS

During the study period, 17,492 unilateral ACLR procedures were recorded. Autograft was used in 98%, most commonly a combined semitendinosus and gracilis graft (77%) or patella tendon graft (31%). Allograft was used in only 1% of the patients. In 52% of cases, ACLR was associated with an additional procedure, with isolated medial meniscal surgery being the most common (21%). Femoral tunnel drilling was mostly performed through an anteromedial portal (73%) and tibial tunnel drilling using an outside-in technique (92%). The most common method of femoral graft fixation was with an Endobutton fixed loop suspensory device (77%), while interference screws predominated for tibial tunnel fixation (86%). Patients who underwent ACLR surgery showed significant improvement in their functional outcome scores at six months, 1 year, 2 years and 5 years postoperatively.

CONCLUSION

Data from the NLR shows a detailed description of the current trends and evolution of ACLR in the United Kingdom over the last 10 years. Satisfactory functional outcomes were observed 5 years postoperatively. This study provides useful information on the prevalence of ACL-associated injuries and current surgical techniques with the aim of improving the quality of clinical care and patients' outcomes. Moreover, it provides surgeons with a benchmark against which to compare current practices and functional outcomes following ACLR across the United Kingdom.

LEVEL OF EVIDENCE

Level III.

Unsupervised Machine Learning of the Combined Danish and Norwegian Knee Ligament Registers: Identification of 5 Distinct Patient Groups With Differing ACL Revision Rates

BACKGROUND

Most clinical machine learning applications use a supervised learning approach using labeled variables. In contrast, unsupervised learning enables pattern detection without a prespecified outcome.

PURPOSE/HYPOTHESIS

The purpose of this study was to apply unsupervised learning to the combined Danish and Norwegian knee ligament register (KLR) with the goal of detecting distinct subgroups. It was hypothesized that resulting groups would have differing rates of subsequent anterior cruciate ligament reconstruction (ACLR) revision.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

K-prototypes clustering was performed on the complete case KLR data. After performing the unsupervised learning analysis, the authors defined clinically relevant characteristics of each cluster using variable summaries, surgeons' domain knowledge, and Shapley Additive exPlanations analysis.

RESULTS

Five clusters were identified. Cluster 1 (revision rate, 9.9%) patients were young (mean age, 22 years; SD, 6 years), received hamstring tendon (HT) autograft (91%), and had lower baseline Knee injury and Osteoarthritis Outcome Score (KOOS) Sport and Recreation (Sports) scores (mean, 25.0; SD, 15.6). Cluster 2 (revision rate, 6.9%) patients received HT autograft (89%) and had higher baseline KOOS Sports scores (mean, 67.2; SD, 16.5). Cluster 3 (revision rate, 4.7%) patients received bone-patellar tendon-bone (BPTB) or quadriceps tendon (QT) autograft (94%) and had higher baseline KOOS Sports scores (mean, 65.8; SD, 16.4). Cluster 4 (revision rate, 4.1%) patients received BPTB or QT autograft (88%) and had low baseline KOOS Sports scores (mean, 20.5; SD, 14.0). Cluster 5 (revision rate, 3.1%) patients were older (mean age, 42 years; SD, 7 years), received HT autograft (89%), and had low baseline KOOS Sports scores (mean, 23.4; SD, 17.6).

CONCLUSION

Unsupervised learning identified 5 distinct KLR patient subgroups and each grouping was associated with a unique ACLR revision rate. Patients can be approximately classified into 1 of the 5 clusters based on only 3 variables: age, graft choice (HT, BPTB, or QT autograft), and preoperative KOOS Sports subscale score. If externally validated, the resulting groupings may enable quick risk stratification for future patients undergoing ACLR in the clinical setting. Patients in cluster 1 are considered high risk (9.9%), cluster 2 patients medium risk (6.9%), and patients in clusters 3 to 5 low risk (3.1%-4.7%) for revision ACLR.

Objectively evaluated physical activity among individuals following anterior cruciate ligament reconstruction: a systematic review and meta-analysis

Objective

To compare time spent in moderate-to-vigorous physical activity (MVPA) per week, MVPA per day, and steps per day between individuals that were subjected to the anterior cruciate ligament reconstruction (ACLR) and healthy control group.

Design

Systematic review and meta-analysis of observational studies.

Data sources

Web of Science, Scopus, and PubMed have been comprehensively searched to identify relevant investigations.

Eligibility criteria for selecting studies

An observational research that objectively evaluated physical activity among respondents with a history of ACLR.

Results

Of 302 records, a total of 12 studies fulfilled the eligibility criteria. Four hundred and forty-three participants underwent the ACLR, 153 men and 290 women. The mean time between anterior cruciate ligament (ACL) surgery and evaluation of analysed outcomes was 34.8 months. The main findings demonstrated that the ACLR group spent less time in weekly MVPA (standardised mean differences (SMD)=-0.43 (95% CI -0.66 to -0.20); mean = -55.86 min (95% CI -86.45 to -25.27); p=0.0003; τ2=0.00), in daily MVPA (SMD=-0.51 95% CI -0.76 to -0.26]; mean = -15.59 min (95% CI -22.93 to -8.25); p<0.0001; τ2=0.00), and they had fewer daily steps (SMD=-0.60 95% CI -0.90 to -0.30); mean = -1724.39 steps (95% CI -2552.27 to -896.50); p<0.0001; τ2=0.00) relative to their non-injured counterparts. Additionally, available investigations indicated that individuals with a history of ACLR participated in 316.8 min of MVPA per week, 67 min in MVPA per day, and 8337 steps per day.

Conclusion

Long-term after ACLR, participants undergoing ACL surgery were less physically active compared with their non-injured peers, and they did not satisfy recommendations regarding steps per day.

PROSPERO registration number

CRD42023431991.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Vitamin D status associates with skeletal muscle loss after anterior cruciate ligament reconstruction

BACKGROUNDAlthough 25-hydroxyvitamin D [25(OH)D] concentrations of 30 ng/mL or higher are known to reduce injury risk and boost strength, the influence on anterior cruciate ligament reconstruction (ACLR) outcomes remains unexamined. This study aimed to define the vitamin D signaling response to ACLR, assess the relationship between vitamin D status and muscle fiber cross-sectional area (CSA) and bone density outcomes, and discover vitamin D receptor (VDR) targets after ACLR.METHODSTwenty-one young, healthy, physically active participants with recent ACL tears were enrolled (17.8 ± 3.2 years, BMI 26.0 ± 3.5 kg/m2). Data were collected through blood samples, vastus lateralis biopsies, dual energy x-ray bone density measurements, and isokinetic dynamometer measures at baseline, 1 week, 4 months, and 6 months after ACLR. The biopsies facilitated CSA, Western blotting, RNA-seq, and VDR ChIP-seq analyses.RESULTSACLR surgery led to decreased circulating bioactive vitamin D and increased VDR and activating enzyme expression in skeletal muscle 1 week after ACLR. Participants with less than 30 ng/mL 25(OH)D levels (n = 13) displayed more significant quadriceps fiber CSA loss 1 week and 4 months after ACLR than those with 30 ng/mL or higher (n = 8; P < 0.01 for post hoc comparisons; P = 0.041 for time × vitamin D status interaction). RNA-seq and ChIP-seq data integration revealed genes associated with energy metabolism and skeletal muscle recovery, potentially mediating the impact of vitamin D status on ACLR recovery. No difference in bone mineral density losses between groups was observed.CONCLUSIONCorrecting vitamin D status prior to ACLR may aid in preserving skeletal muscle during recovery.FUNDINGNIH grants R01AR072061, R01AR071398-04S1, and K99AR081367.

The influence of body mass index on physical activity engagement following anterior cruciate ligament reconstruction: A systematic literature review

Background

The objective of this study was to summarize available literature that explored the impact of body mass index (BMI) on physical activity participation among individuals who were subjected to the anterior cruciate ligament reconstruction (ACLR).

Methods

A total of three electronic databases, including Web of Science, Scopus, and PubMed, were comprehensively searched to identify relevant investigations. The following inclusion criteria were applied: (1) study design was observational; (2) participants underwent the ACLR; (3) BMI was estimated as a predictor variable; and (4) outcomes evaluated referred to physical activity. The risk of bias was assessed with the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies.

Results

After a database search, 787 studies were found, and only 10 of them met each of the eligibility criteria and were included in the qualitative analysis. Regarding respondents' characteristics, 7171 individuals underwent ACLR, 4080 males and 3091 females, with a mean age of 25.5 years. Most importantly, the average BMI of the examined population was 24.9 kg/m2. In all studies, physical activity was evaluated subjectively using the Tegner activity scale and the Marx activity scale. The main findings unambiguously demonstrated that a negative relationship between BMI and physical activity engagement was observed. More specifically, there is convincing evidence that BMI over 25 kg/m2 harmfully affected subjectively assessed physical activity in individuals with a history of ACLR.

Conclusion

The results obtained in the presented research indicated that increased values of BMI were a factor that correlated with reduced physical activity levels in the ACLR population. Hence, taking into account the clinical and health implications of reduced physical activity participation, stimulation of a healthy lifestyle, such as a combination of adequately designed physical exercise and nutrition, seems necessary for the analyzed population.

Comparing Short-Term Knee-Related Quality of Life and Associated Clinical Outcomes Between Youth With and Without a Sport-Related Knee Injury

OBJECTIVE

To compare short-term changes in knee-related quality of life (QOL) and associated clinical outcomes between youth with and without a sport-related knee injury.

DESIGN

Prospective cohort study.

SETTING

Sport medicine and physiotherapy clinics.

PARTICIPANTS

Youth (11-19 years old) who sustained an intra-articular, sport-related knee injury in the past 4 months and uninjured youth of similar age, sex, and sport.

INDEPENDENT VARIABLE

Injury history.

MAIN OUTCOME MEASURES

Knee-related QOL (Knee injury and Osteoarthritis Outcome Score, KOOS), knee extensor and flexor strength (dynamometry), physical activity (accelerometer), fat mass index (FMI; bioelectrical impedance), and kinesiophobia (Tampa Scale for Kinesiophobia, TSK) were measured at baseline (within 4 months of injury) and at 6-month follow-up. Wilcoxon rank sum tests assessed between-group differences for all outcomes. Regression models assessed the association between injury history and outcome change (baseline to 6-month follow-up), considering sex. The influence of injury type, baseline values, and physiotherapy attendance was explored.

RESULTS

Participants' (93 injured youth, 73 uninjured control subjects) median age was 16 (range 11-20) years and 66% were female. Despite greater improvements in KOOS QOL scores (20; 95% confidence interval, 15-25), injured participants demonstrated deficits at 6-month follow-up (z = 9.3, P < 0.01) compared with control subjects, regardless of sex. Similar findings were observed for knee extensor and flexor strength and TSK scores but not for physical activity or FMI. Lower baseline values were associated with greater outcome changes in injured youth.

CONCLUSIONS

Youth have worse knee-related QOL, muscle strength, and kinesiophobia early after a sport-related knee injury than control subjects. Despite improvements, deficits persist 6 months later.

Autograft patellar bone-tendon-bone use does not increase operative time in anterior cruciate ligament reconstruction

Background

Anterior cruciate ligament reconstruction (ACLR) is a common procedure that has been shown to have relatively good outcomes amongst various graft types. Operative time in ACLR has been found to influence outcomes and cost. The purpose of this study was to evaluate the association of operative time in primary arthroscopically performed anterior cruciate ligament reconstruction (ACLR) and graft type while controlling for confounders that influence time.

Methods

All patients who received ACLR between 2018 and 2022 were included in this retrospective cohort study. Exclusion criteria consisted of age (≤16 years), revisions, concomitant ligament reconstruction or tendon repairs, or other simultaneously performed procedures that could potentially add substantial variation in operative time. The primary outcome was operative time. Graft types included allograft, bone-tendon-bone (BTB) autograft, hamstring tendon (HS) autograft and quadriceps tendon (QT) autograft.

Results

A total of 1813 primary ACLRs were included. The average operative time was 98.9 ± 33.0 min. Graft utilization varies considerably among surgeons. The most used graft type was BTB autograft (42.6%) followed by HS autograft (32.3%) and allograft (21.4%). Only 68 cases (3.8%) used a QT autograft. Seven of the 15 included surgeons primarily used BTB autograft. One surgeon predominately used QT autograft. No difference in operative time was observed among the autograft types (p = 0.342). Allograft ACLR was significantly faster by 27-33 min compared to using BTB autograft, HS autograft, or QT autograft (p < 0.001).

Conclusion

Operative time did not vary by type of autograft selected. Allograft ACLR was performed approximately 30 min faster than autograft ACLR. Further studies examining the effect on patient outcomes of reduced operative time and minimizing graft harvest morbidity in ACLR is important to more accurately determine the cost-effectiveness of allograft ACLR.

Technology-assisted anterior cruciate ligament reconstruction improves tunnel placement but leads to no change in clinical outcomes: a systematic review and meta-analysis

PURPOSE

To investigate the effect of technology-assisted Anterior Cruciate Ligament Reconstruction (ACLR) on post-operative clinical outcomes and tunnel placement compared to conventional arthroscopic ACLR.

METHODS

CENTRAL, MEDLINE, and Embase were searched from January 2000 to November 17, 2022. Articles were included if there was intraoperative use of computer-assisted navigation, robotics, diagnostic imaging, computer simulations, or 3D printing (3DP). Two reviewers searched, screened, and evaluated the included studies for data quality. Data were abstracted using descriptive statistics and pooled using relative risk ratios (RR) or mean differences (MD), both with 95% confidence intervals (CI), where appropriate.

RESULTS

Eleven studies were included with total 775 patients and majority male participants (70.7%). Ages ranged from 14 to 54 years (391 patients) and follow-up ranged from 12 to 60 months (775 patients). Subjective International Knee Documentation Committee (IKDC) scores increased in the technology-assisted surgery group (473 patients; P = 0.02; MD 1.97, 95% CI 0.27 to 3.66). There was no difference in objective IKDC scores (447 patients; RR 1.02, 95% CI 0.98 to 1.06), Lysholm scores (199 patients; MD 1.14, 95% CI - 1.03 to 3.30) or negative pivot-shift tests (278 patients; RR 1.07, 95% CI 0.97 to 1.18) between the two groups. When using technology-assisted surgery, 6 (351 patients) of 8 (451 patients) studies reported more accurate femoral tunnel placement and 6 (321 patients) of 10 (561 patients) studies reported more accurate tibial tunnel placement in at least one measure. One study (209 patients) demonstrated a significant increase in cost associated with use of computer-assisted navigation (mean 1158€) versus conventional surgery (mean 704€). Of the two studies using 3DP templates, production costs ranging from $10 to $42 USD were cited. There was no difference in adverse events between the two groups.

CONCLUSION

Clinical outcomes do not differ between technology-assisted surgery and conventional surgery. Computer-assisted navigation is more expensive and time consuming while 3DP is inexpensive and does not lead to greater operating times. ACLR tunnels can be more accurately located in radiologically ideal places by using technology, but anatomic placement is still undetermined because of variability and inaccuracy of the evaluation systems utilized.

LEVEL OF EVIDENCE

Level III.

Prevalence and Predictors of Postoperative Depression and Anxiety After Anterior Cruciate Ligament Reconstruction

PURPOSE

Preoperative mood disorders influence postoperative outcomes after anterior cruciate ligament (ACL) reconstruction (ACLR), but the prevalence and risk factors associated with postoperative depression/anxiety development remain unknown. The purposes of this study were to quantify the prevalence of postoperative diagnoses of depression or anxiety following ACLR in patients under the age of 25 and assess the interplay between patient sex and ACL reoperation on the prevalence of a depression or anxiety diagnosis following ACLR.

METHODS

ACLR patients under the age of 25 years old were identified in the Truven Healthcare Marketscan database. Patients with incomplete coverage +/- one year of the index surgical procedure were excluded. Patients were categorized by the presence of preoperative, postoperative, or no depression/anxiety using the International Classification of Diseases, Ninth Revision (ICD-9) codes. We compared patient demographics and reoperation rates following the index ACLR between the depression and anxiety categories. Additionally, logistic regression was fit to assess the interaction between sex and either ipsilateral or contralateral ACL surgery on postoperative depression/anxiety diagnosis.

RESULTS

Of the 42,174 patients, 10.7% had a new depression/anxiety diagnosis after ACLR. Postoperative depression/anxiety was nearly twice as prevalent for females (F: 14.4%, M: 7.6%) despite having similar rates of secondary ACLR (F: 15.5%, M: 13.0%). Those with postoperative depression/anxiety had a considerably greater prevalence of reoperation (18.8%) than those without depression/anxiety (13.7%) and those with pre-existing preoperative depression/anxiety (12.9%). Sex and reoperation were independently associated with postoperative depression/anxiety diagnosis.

CONCLUSION

Female sex and secondary ACL surgery are independently associated with an increased prevalence of postoperative depression/anxiety. Nearly one in seven young females are diagnosed with depression/anxiety after ACLR. Similarly, a greater proportion of patients who suffer a secondary ACL surgery are subsequently diagnosed with depression/anxiety. The orthopedic community must be cognizant of the increased risk of postoperative depression/anxiety for females and those who suffer a secondary ACL surgery, and screening for depression/anxiety in these at-risk populations with referrals to mental health professionals may be warranted.

Return to active duty after anterior cruciate ligament reconstruction (ACLR) in Chinese male military aircrews

Background

Surgically treated anterior cruciate ligament (ACL) injuries may be a waivable condition and allow return to full flight status, but waivers are based on expert opinion rather than recent published data. The purpose of this study was to evaluate return to flight after anterior cruciate ligament reconstruction (ACLR) in male military aircrews with ACL injuries and to identify factors that affect flight clearance.

Method

A single-center retrospective review was conducted by the authors for all active-duty aircrew who underwent ACLR at an authorized military medical center from January 2010 to December 2019. Demographic characteristics, occupational information, surgical data, and flight readiness evaluation outcomes were collected. Based on the final medical evaluation, subjects were divided into a qualified group (N = 64) and a disqualified group (N = 9), and the difference in data collected between the two groups was then analyzed to identify factors affecting flight clearance.

Results

A total of 73 patients underwent successful ACLR with a mean age of 31.6 ± 5.6 years. Non-contact injury was the main type of ACL injury, accounting for 84.9% of the total injuries. 55 cases (75.3%) occurred during daily sports activities and 18 (24.7%) during military training. 64 of the 73 crewmembers (87.7%) were able to return to flight at their last follow-up evaluation. The preoperative interval time (PIT) was significantly less in the qualified group than in the disqualified group (P = 0.002). Patients who underwent ACLR within three months were more likely to return to flying than those who underwent the procedure three months later (97.4% vs. 76.5%, P = 0.010). The incidence of failure to return to flight duty was significantly higher in aircrews with ACL injuries combined with meniscal injuries than in aircrews with isolated ACL injuries (21.4% vs. 0.0%, P = 0.017).

Conclusion

ACLR appears to be safe for military aircrew suffering ACL injuries with or without meniscal injury, and return to flight status is the most likely outcome for the majority of postoperative pilots. Prolonged PIT, PIT > 3 months, and ACL injury combined with meniscus injury had a negative impact on postoperative flight readiness.

Allograft Anterior Cruciate Ligament Reconstruction Fails at a Greater Rate in Patients Younger Than 34 Years

Purpose

To characterize the secondary anterior cruciate ligament (ACL) injury rates after primary allograft anterior cruciate ligament reconstruction (ACLR) and to identify the age cut-score at which the risk of allograft failure decreases.

Methods

All patients who underwent primary ACLR within a single orthopaedic department between January 2005 and April 2020 were contacted at a minimum of 2 years post-ACLR to complete a survey regarding complications experienced post-surgery, activity level, and perceptions of knee health. Patients were excluded for incidence of previous ACLR (ipsilateral or contralateral) and/or age younger than 14 years. Relative proportions were calculated, binary regression analysis was performed, and receiver operating characteristic analysis was used to identify the threshold age for maximal sensitivity and specificity to predict high risk of allograft failure, defined as undergoing revision ACLR.

Results

Of the 939 surveys completed, 398 patients underwent primary allograft ACLR (mean age 39.5 years; range 16.0-66.1 years; 54.3% female). The secondary ACL injury rate was 11.6% (5.8% ipsilateral revision ACLR, 5.8% contralateral ACL injury). Male and female patients had similar revision (5.5% male, 6.0% female, P = .82) and contralateral ACL injury rates (6.6% male, 5.1% female, P = .52). Receiver operating characteristic analysis indicated that age ≤34 years was threshold for differentiating high risk of allograft failure (area under the curve 0.65, 95% confidence interval 0.55-0.76; P = .014). Patients aged ≤34 years had a greater secondary injury rate than patients >34 years (20.4% (10.2% revision ACLR, 10.2% contralateral ACL injury) versus 6.9% (3.5% revision ACLR, 3.5% contralateral ACL injury; P < .001). Binary regression analysis demonstrated that decreasing age was associated with increased risk of graft failure (χ2 = 7.9, P = .02.).

Conclusions

Allograft ACLR showed similar failure rates between sexes but displayed suboptimal graft failure outcomes in younger and active patients. By age 34 years, the increased revision risk for younger patients diminished.

Level of Evidence

Level IV, therapeutic case series.

Youth With a Sport-Related Knee Injury Exhibit Significant and Persistent Knee-Related Quality-of-Life Deficits at 12-Month Follow-up Compared to Uninjured Peers

OBJECTIVE: We aimed to compare knee-related quality of life (QOL) between youth with and without an intra-articular, sport-related knee injury at baseline (≤4 months postinjury), 6-month, and 12-month follow-up, and assess the association between clinical outcomes and knee-related QOL. DESIGN: Prospective cohort study. METHODS: We recruited 86 injured and 64 uninjured youth (similar age, sex, sport). Knee-related QOL was assessed with the Knee injury and Osteoarthritis Outcome Score (KOOS) QOL subscale. Linear mixed models (95% confidence interval [CI]; clustered on sex and sport) compared KOOS QOL between study groups over the study period, considering sex-based differences. We also explored the association of injury type (anterior cruciate ligament [ACL]/meniscus injury or other), knee extensor strength (dynamometry), moderate-to-vigorous physical activity (accelerometer), intermittent knee pain (Intermittent and Constant Osteoarthritis Pain [ICOAP] measure), and fear of reinjury (17-item Tampa Scale of Kinesiophobia) with knee-related QOL. RESULTS: Participant median (range) age was 16.4 (10.9-20.1) years, 67% were female, and 56% of injuries were ACL ruptures. Injured participants had lower mean KOOS QOL scores at baseline (-61.05; 95% CI: -67.56, -54.53), 6-month (-41.37; 95% CI: -47.94, -34.80), and 12-month (-33.34; 95% CI: -39.86, -26.82) follow-up, regardless of sex. Knee extensor strength (6- and 12-month follow-up), moderate-to-vigorous physical activity (12-month follow-up), and ICOAP (all time points) were associated with KOOS QOL in injured youth. Additionally, having an ACL/meniscus injury and higher Tampa Scale of Kinesiophobia scores were associated with worse KOOS QOL in injured youth. CONCLUSION: Youth with a sport-related knee injury have significant, persistent knee-related QOL deficits at 12-month follow-up. Knee extensor strength, physical activity, pain, and fear of reinjury may contribute to knee-related QOL. JOSPT 2023;53(8):1-10. Epub: 20 June 2023. doi:10.2519/jospt.2023.11611.

LigaNET: A multi-modal deep learning approach to predict the risk of subsequent anterior cruciate ligament injury after surgery

Anterior cruciate ligament (ACL) injuries are a common cause of soft tissue injuries in young active individuals, leading to a significant risk of premature joint degeneration. Postoperative management of such injuries, in particular returning patients to athletic activities, is a challenge with immediate and long-term implications including the risk of subsequent injury. In this study, we present LigaNET, a multi-modal deep learning pipeline that predicts the risk of subsequent ACL injury following surgical treatment. Postoperative MRIs (n=1,762) obtained longitudinally between 3 to 24 months after ACL surgery from a cohort of 159 patients along with 11 non-imaging outcomes were used to train and test: 1) a 3D CNN to predict subsequent ACL injury from segmented ACLs, 2) a 3D CNN to predict injury from the whole MRI, 3) a logistic regression classifier predict injury from non-imaging data, and 4) a multi-modal pipeline by fusing the predictions of each classifier. The CNN using the segmented ACL achieved an accuracy of 77.6% and AUROC of 0.84, which was significantly better than the CNN using the whole knee MRI (accuracy: 66.6%, AUROC: 0.70; P<.001) and the non-imaging classifier (accuracy: 70.1%, AUROC: 0.75; P=.039). The fusion of all three classifiers resulted in highest classification performance (accuracy: 80.6%, AUROC: 0.89), which was significantly better than each individual classifier (P<.001). The developed multi-modal approach had similar performance in predicting the risk of subsequent ACL injury from any of the imaging sequences (P>.10). Our results demonstrate that a deep learning approach can achieve high performance in identifying patients at high risk of subsequent ACL injury after surgery and may be used in clinical decision making to improve postoperative management (e.g., safe return to sports) of ACL injured patients.

Long-Term Bilateral Neuromuscular Function and Knee Osteoarthritis after Anterior Cruciate Ligament Reconstruction

Neuromuscular function is thought to contribute to posttraumatic osteoarthritis (PTOA) risk in anterior cruciate ligament (ACL)-reconstructed (ACLR) patients, but sensitive and easy-to-use tools are needed to discern whether complex muscle activation strategies are beneficial or maladaptive. Using an electromyography (EMG) signal analysis technique coupled with a machine learning approach, we sought to: (1) identify whether ACLR muscle activity patterns differed from those of healthy controls, and (2) explore which combination of patient outcome measures (thigh muscle girth, knee laxity, hop distance, and activity level) predicted the extent of osteoarthritic changes via magnetic resonance imaging (MRI) in ACLR patients. Eleven ACLR patients 10-15 years post-surgery and 12 healthy controls performed a hop activity while lower limb muscle EMG was recorded bilaterally. Osteoarthritis was evaluated based on MRI. ACLR muscle activity patterns were bilaterally symmetrical and differed from those of healthy controls, suggesting the presence of a global adaptation strategy. Smaller ipsilateral thigh muscle girth was the strongest predictor of inferior MRI scores. The ability of our EMG analysis approach to detect meaningful neuromuscular differences that could ultimately be related to thigh muscle girth provides the foundation to further investigate a direct link between muscle activation patterns and PTOA risk.

Knee- and Overall Health-Related Quality of Life Following Anterior Cruciate Ligament Injury: A Cross-sectional Analysis of Australian and Canadian Cohorts

OBJECTIVE: To describe the knee- and overall health-related quality of life (QOL) 3 to 12 years after anterior cruciate ligament (ACL) tear, and to assess the association of clinical and structural features with QOL after ACL tear. DESIGN: Cross-sectional analysis of combined data from Australian (n = 76, 5.4 years postinjury) and Canadian (n = 50, 6.6 years postinjury) prospective cohort studies. METHODS: We conducted a secondary analysis of patient-reported outcomes and index knee magnetic resonance imaging (MRI) acquired in 126 patients (median 5.5 [range: 4-12] years postinjury), all treated with ACL reconstruction. Outcomes included knee (ACL Quality of Life questionnaire [ACL-QOL]) and overall health-related QOL (EQ-5D-3L). Explanatory variables were self-reported knee pain (Knee Injury and Osteoarthritis Outcome Score [KOOS-Pain subscale]) and function (KOOS-Sport subscale), and any knee cartilage lesion (MRI Osteoarthritis Knee Score). Generalized linear models were adjusted for clustering between sites. Covariates were age, sex, time since injury, injury type, subsequent knee injuries, and body mass index. RESULTS: The median [range] ACL-QOL score was 82 [24-100] and EQ-5D-3L was 1.0 [-0.2 to 1.0]. For every 10-point higher KOOS-Sport score, the ACL-QOL score increased by 3.7 points (95% confidence interval [CI]: 1.7, 5.7), whereas there was no evidence of an association with the EQ-5D-3L (0.00 points, 95% CI: -0.02, 0.02). There were no significant association between KOOS-Pain and ACL-QOL (4.9 points, 95% CI: -0.1, 9.9) or EQ-5D-3L (0.05 points, 95% CI: -0.01, 0.11), respectively. Cartilage lesions were not associated with ACL-QOL (-1.2, 95% CI: -5.1, 2.7) or EQ-5D-3L (0.01, 95% CI: -0.01, 0.04). CONCLUSION: Self-reported function was more relevant for knee-related QOL than knee pain or cartilage lesions after ACL tear. Self-reported function, pain, and knee structural changes were not associated with overall health-related QOL. J Orthop Sports Phys Ther 2023;53(7):1-12. Epub: 8 June 2023. doi:10.2519/jospt.2023.11838.

Influence of Graft Type on Lower Extremity Functional Test Performance and Failure Rate After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Both autografts and allografts are used to reconstruct the anterior cruciate ligament (ACL) after injury; however, it is unclear whether graft source affects lower extremity functional test performance or failure rate in an active military population.

OBJECTIVE

To compare lower extremity functional test performance and graft failure rates between ACL grafts [allograft, hamstring, bone-patellar tendon-bone (BTB)].

STUDY DESIGN

Cross-sectional.

LEVEL OF EVIDENCE

Level 2.

METHODS

Ninety-eight cadets entering a US Service Academy with a history of unilateral ACL reconstruction (ACLR) agreed to participate. Before basic training, participants completed 4 lower extremity functional tests. Active injury surveillance was conducted within the study cohort to identify all subsequent graft failures.

RESULTS

Cadets with hamstring autografts outperformed the BTB and allograft groups on the Lower Quarter Y-Balance Test-Posteromedial direction and single-leg hop test, respectively. No differences were detected by graft type for the other functional tests. The incidence of subsequent ipsilateral graft failures in patients with autograft was 8.11%. No failures were observed in the allograft group during the follow-up period. After controlling for sex, joint hypermobility, and time since injury and surgery, the risk of graft failure was 9.8 times higher for patients with a hamstring autograft than with a BTB (P = 0.045).

CONCLUSION

After ACLR, graft type appears to influence some single-limb measures of lower extremity function and the risk of subsequent failure. Hamstring autografts demonstrated better functional performance but increased risk of graft failure.

CLINICAL RELEVANCE

Surgeons need to weigh the pros and cons of all graft options in relation to the patient's lifestyle. Regardless of graft type, individuals with an ACLR may require additional rehabilitation to regain neuromuscular control during dynamic single-limb tasks and mitigate graft failure.

Joint Injury, Osteoarthritis, and Cardiovascular Disease Risk Factors in Former National Football League Athletes: An NFL-LONG Study

CONTEXT

Individuals with lower extremity osteoarthritis (OA) have a 25% greater risk of cardiovascular disease (CVD) than those without OA. The prevalence of traumatic joint injuries among National Football League (NFL) players exposes these athletes to an elevated risk for OA and potentially a greater risk of cardiovascular risk factors (CRFs) and CVD.

OBJECTIVES

To examine the associations between a history of lower extremity joint injury, lower extremity OA, and the prevalence of CRFs and CVD among former NFL athletes.

DESIGN

Cross-sectional study.

PATIENTS OR OTHER PARTICIPANTS

Former NFL players completed a comprehensive health questionnaire that was used in an ongoing study, the Neurologic Function Across the Lifespan: A Prospective, Longitudinal, and Translational Study for Former NFL Players (NFL-LONG). A subsample of 1738 former players reported lifetime medical diagnoses including CVD or CRFs.

MAIN OUTCOME MEASURE(S)

Crude and adjusted prevalence ratios (PRsadj) characterized the associations between CVD or CRFs and injury, OA diagnosis, or both among athletes who reported (1) no history of lower extremity joint injury or surgery and no diagnosed OA, (2) a history of lower extremity joint injury or surgery and no diagnosed OA, and (3) a history of lower extremity joint injury or surgery and diagnosed OA.

RESULTS

Neither a history of lower extremity joint injury (PRadj = 1.34; 95% CI = 0.86, 2.07) nor a history of lower extremity joint injury and diagnosed OA (PRadj = 1.41; 95% CI = 0.89, 2.25) was significantly associated with CVD. However, CRFs were 30% and 53% more prevalent in former players with lower extremity joint injury and no diagnosed OA (PRadj = 1.30; 95% CI = 1.12, 1.50) and those with lower extremity joint injury and diagnosed OA (PRadj = 1.53; 95% CI = 1.31, 1.78), respectively, versus athletes with no history of either condition.

CONCLUSIONS

The prevalence of CRFs was highest among former NFL athletes with a history of lower extremity joint injury and diagnosed OA. These findings provide insight regarding the potential pathways to chronic diseases that may be initiated by joint injury early in life.

Patients With Low Resilience Scores Have Significantly Worse Postoperative Outcomes After Anterior Cruciate Ligament Reconstruction Than Patients With Normal or High Resilience Scores

Purpose

To evaluate the relationship between patient resilience and patient-reported outcome measures (PROMS) after primary anterior cruciate ligament (ACL) reconstruction.

Methods

Patients who underwent an ACL reconstruction by a single surgeon between January 2012 and June 2020 were identified by an institutional query using Current Procedural Terminology codes. Patients were included if they (1) underwent a primary ACL reconstruction and (2) had a minimum of 2 years' follow-up. Data were retrospectively collected regarding demographics, surgical details, visual analog scale (VAS) scores, and 12-item short form survey (SF-12) scores. Resilience scores were obtained via the Brief Resilience Scale questionnaire. Stratification into low (LR), normal (NR), and high resilience (HR) was based on standard deviation from mean Brief Resilience Scale score to determine differences in PROMS between groups.

Results

One-hundred eighty-seven patients were identified by the institutional query. Of the 187 patients, 180 met inclusion criteria. Seven patients underwent revision ACL reconstruction and were excluded from the study. One-hundred three patients (57.2%) completed the postoperative questionnaire and were included. Patients in the NR group and HR group had significantly greater postoperative SF-12 scores (P < .001) and lower postoperative VAS pain scores (P < .001) when compared with those of the LR group. This trend was again shown with breakdown of the SF-12 into physical and mental aspects, each of which were significantly greater in either the NR group or HR group when compared with the LR group (P < .001). Overall, 97.9% and 99.0% of patients had changes in their SF-12 total and VAS pain scores respectively that exceeded the minimal clinically important difference for the cohort.

Conclusions

Patients with lower resilience scores have worse PROMs and increased pain than patients with greater resilience at a minimum of 2-year follow-up after ACL reconstruction.

Level of Evidence

Level IV, prognostic case series.

Long-term Quality of Life in Patients After ACL Reconstruction With Concomitant Meniscal Injury Treatment: Patient-Reported Outcomes at Minimum 10-Year Follow-up

Background

Long-term studies of patients after anterior cruciate ligament (ACL) reconstruction with or without concomitant meniscal tear treatment are limited.

Purposes

To (1) report postoperative outcomes after anatomic ACL reconstruction with a hamstring autograft, (2) investigate how concomitant treatment of meniscal injury could affect these outcomes, and (3) evaluate the association between quality of life and activity levels at a minimum 10-year follow-up.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients treated with a unilateral, anatomic ACL reconstruction between 2005 and 2011 were investigated. The following patient-reported outcome measures (PROMs) were reported for the overall sample as well as a subsample of patients with meniscal injury: International Knee Documentation Committee Subjective Knee Form (IKDC-SKF), Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm knee score, Tegner activity scale, 5-level EQ-5D (EQ-5D-5L), and patient satisfaction. Sex, age, body mass index (BMI), and meniscal injury treatment (meniscectomy vs meniscal repair) were examined as patient-specific risk factors regarding long-term activity and quality of life.

Results

Overall, 106 patients, 90 men (85%) and 16 women (15%), were enrolled in the study, with a mean follow-up of 13.2 years. The ACL retear rate was 2.8%. The mean scores were 80.6 ± 16.7 (IKDC-SKF), 87.4 ± 15.0 (KOOS), 90.5 ± 11.5 (Lysholm), 5.6 ± 1.9 (Tegner), and 91.8 ± 14.5 (EQ-5D-5L). The majority (90.6%) of patients considered their knee state satisfactory during follow-up. When compared with patients who underwent meniscal repair, patients who underwent meniscectomy had statistically significantly lower scores on all PROMs except for the Tegner and EQ-5D-5L (P < .05 for all). The mean difference between the 2 groups was ≥7 points on all PROM scores. Patient sex, age, and BMI did not affect PROM scores. There was a statistically significant, strong positive correlation between quality of life and activity.

Conclusion

Patients had few or no symptoms and considered their knee state satisfactory 13.2 years after anatomic ACL reconstruction. Patients with concomitant meniscal tears having undergone meniscal repair had improved PROMs compared with those treated with meniscectomy. Finally, participation in activities of daily living and sports was interrelated with quality of life and was not affected by patient age, sex, or BMI.

Improvement Trajectories in Patient-Reported Outcomes Between Males and Females After Anterior Cruciate Ligament Reconstruction

CONTEXT

Patient-reported outcomes (PROs) are used to track recovery and inform clinical decision-making after anterior cruciate ligament reconstruction (ACLR). Whether sex influences the trajectory of improvements in PROs over time post-ACLR remains unclear.

OBJECTIVES

To (1) examine the effect of sex on the association between months post-ACLR and Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QOL) scores in individuals with ACLR and (2) assess sex differences in the KOOS QOL score at selected timepoints post-ACLR.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 133 females (20± 3 years) and 85 males (22 ± 4 years) within 6 to 60 months of primary, unilateral ACLR.

MAIN OUTCOME MEASURE(S)

The KOOS QOL was completed at a single follow-up timepoint post-ACLR. A multivariate linear regression model was calculated to assess the interaction of sex on the association between months post-ACLR and KOOS QOL score. Sex-specific linear regression models were then used to predict KOOS QOL estimated marginal means at each clinical timepoint (6, 12, 24, 36, 48, and 60 months post-ACLR) and compare the sexes.

RESULTS

In the primary model (R2 = 0.16, P < .0001), a significant interaction existed between sex and time post-ACLR (β = -0.46, P < .01). Greater months post-ACLR were associated with better KOOS QOL scores for males (R2 = 0.29, β = 0.69, P < .001); months post-ACLR was a weaker predictor of KOOS QOL scores for females (R2 = 0.04, β = 0.23, P < .02). Estimated marginal means for KOOS QOL scores were greater for males than females at 36 months (t210 = 2.76, P < .01), 48 months (t210 = 3.02, P < .01), and 60 months (t210 = 3.09, P = .02) post-ACLR.

CONCLUSIONS

Males exhibited PRO improvement post-ACLR as the months post-ACLR increased, whereas females did not demonstrate the same magnitude of linear increase in KOOS QOL score. Females may require extended intervention to improve clinical outcomes post-ACLR and address a plateau in QOL score.

Outcome analysis of infrapatellar fat pad partial resection or preservation in patients with anterior cruciate ligament reconstruction

The infrapatellar fat pad (IPFP) is one of the structures surrounding the knee joint that obscures exposure in minimally arthroscopy anterior cruciate ligament reconstruction (ACLR). Most surgeons excise the partial fat pad for better exposure of the knee. However, whether removal of IPFP in ACLR remained inconclusive. The purpose of this study was to investigate clinical outcomes of IPFP preservation or resection in patients with primary hamstring-graft ACLR. A total of 104 patients were assigned to receive either IPFP-R (n = 55) or IPFP-P (n = 49). There were no significant preoperative differences between the two groups. The anterior knee pain (AKP) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) in the two groups both recovered compared with those at baseline, but the IPFP-P group recovered more significantly at 3-, 6-, 12-month, and 3-, 6-month of follow-up, respectively. When assessing the KOOS subclasses using minimum perceptible clinical improvement (MPCI), patients with IPFP-R failed to make significant improvement at 3 months in the symptoms, pain and sports subsets of the KOOS. Knee-related complications were not significantly different between the two groups, while the resection group had a higher incidence. These results suggested that ACLR with primary hamstring grafts can achieve good effects whether performed with IPFP resection or preservation; however, the improvements in anterior knee pain and knee joint functions are better for the patients with IPFP preservation. Therefore, surgeons should avoid the resection of IPFP as much as possible while fully exposing the wild view to ensure the ACLR.

Age-, Sex-, and Graft-Specific Reference Values From 783 Adolescent Patients at 5 to 7 Months After ACL Reconstruction: IKDC, Pedi-IKDC, KOOS, ACL-RSI, Single-Leg Hop, and Thigh Strength

OBJECTIVE: To describe age-, sex-, and graft source-specific reference values for patient-reported, physical function, and strength outcome measures in adolescents at 5 to 7 months after anterior cruciate ligament reconstruction. DESIGN: Cross-sectional study. METHODS: Data were collected at 3 universities and 2 children's hospitals. The participants completed at least one of the International Knee Documentation Committee (IKDC) Subjective Evaluation Form, Pediatric IKDC (Pedi-IKDC), Knee Injury and Osteoarthritis Outcomes Score (KOOS), and Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) Scale. Participants also completed single-leg hop tests and/or isokinetic quadriceps and hamstrings strength assessments (at 60°/s). Reference values were summarized using descriptive statistics and stratified for age, sex, and graft source. RESULTS: Reference values were reported for common patient-reported outcomes and measures of physical function and strength from 783 participants (56% females, age = 16. 4 ± 2.0 years) who were in early adolescence (12-14 years, N = 183, 52% females), middle adolescence (15-17 years, N = 456, 58% females), or late adolescence (18-20 years, N = 144, 55% females). Three hundred seventy-nine participants (48.4%) received a bone-patellar tendon-bone autograft, 292 participants (37.3%) received hamstring tendon autograft, and 112 participants (14.3%) received autograft or allograft from an alternative source. CONCLUSION: Reference values for common patient-reported outcomes and measures of physical function and strength differed depending on a patient's age, sex, and graft source. Using patient-specific reference values, in addition to previously described age-appropriate cutoff values, may help clinicians monitor and progress patients through rehabilitation and return to physical activity after anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther 2023;53(4):1-8. Epub: 23 January 2023. doi:10.2519/jospt.2023.11389.

Preoperative factors associated with failure to reach the patient acceptable symptom state after anterior cruciate ligament reconstruction in patients aged 40 and older

PURPOSE

To perform a predictive analysis to identify preoperative patient factors associated with failure to achieve a newly defined patient acceptable symptom state (PASS) for the International Knee Documentation Committee (IKDC) Score after anterior cruciate ligament reconstruction (ACLR) in patients aged ≥ 40 years with a minimum of 2-year follow-up.

METHODS

This was a secondary analysis of a retrospective review of all patients aged 40 years or older receiving a primary allograft ACLR at a single institution between the years of 2005 and 2016, with 2-year minimum follow-up. Using an updated PASS threshold of 66.7 for the International Knee Documentation Committee (IKDC) score previously established for this patient cohort, a univariate and multivariate analysis was performed to identify preoperative patient characteristics predictive of failure to achieve PASS.

RESULTS

A total of 197 patients with a mean follow-up of 6.2 ± 2.1 years (range 2.7 - 11.2) were included in the analysis (48.5 ± 5.6 years, 51.8% female, Body Mass Index (BMI) 25.9 ± 4.4). PASS was achieved by 162 patients (82.2%). Patients who failed to achieve PASS more often had lateral compartment cartilage defects (P = 0.001) and lateral meniscus tears (P = 0.004), higher BMIs (P = 0.004), and Workers' Compensation status (P = 0.043) on univariable analysis. Factors predictive of failure to achieve PASS on multivariable analysis included BMI and lateral compartment cartilage defect (OR 1.12 [1.03-1.23], P = 0.013; OR 5.1 [1.87-13.9], P = 0.001).

CONCLUSION

Among patients ≥ 40 years who receive a primary allograft ACLR, patients who fail to achieve PASS more often had lateral compartment cartilage defects and higher BMIs.

LEVEL OF EVIDENCE

Level IV.

Survival of anterior cruciate ligament reconstructions in active-duty military populations

PURPOSE

Anterior cruciate ligament tears and anterior cruciate ligament reconstruction (ACLR) are common in young athletes. The modifiable and non-modifiable factors contributing to ACLR failure and reoperation are incompletely understood. The purpose of this study was to determine ACLR failure rates in a physically high-demand population and identify the patient-specific risk factors, including prolonged time between diagnosis and surgical correction, that portend failure.

METHODS

A consecutive series of military service members with ACLR with and without concomitant procedures (meniscus [M] and/or cartilage [C]) done at military facilities between 2008 and 2011 was completed via the Military Health System Data Repository. This was a consecutive series of patients without a history of knee surgery for two years prior to the primary ACLR. Kaplan-Meier survival curves were estimated and evaluated with Wilcoxon test. Cox proportional hazard models calculated hazard ratios (HR) with 95% confidence intervals (95% CI) to identify demographic and surgical factors that influenced ACLR failure.

RESULTS

Of the 2735 primary ACLRs included in the study, 484/2,735 (18%) experienced ACLR failure within four years, including (261/2,735) (10%) undergoing revision ACLR and (224/2,735) (8%) due to medical separation. The factors that increased failure include Army Service (HR 2.19, 95% CI 1.67, 2.87), > 180 days from injury to ACLR (HR 1.550, 95% CI 1.157, 2.076), tobacco use (HR 1.429 95% CI 1.174, 1.738), and younger patient age (HR 1.024, 95% CI 1.004, 1.044).

CONCLUSION

The overall clinical failure rate of service members with ACLR is 17.7% with minimum four-year follow-up, where more patients are likely to fail due to revision surgery than medical separation. The cumulative probability of survival at 4 years was 78.5%. Smoking cessation and treating ACLR patients promptly are modifiable risk factors impacting either graft failure or medical separation.

LEVEL OF EVIDENCE

Level III.

Degenerative changes through MR cartilage mapping in anterior cruciate ligament-reconstructed knees

Background

Anterior cruciate ligament (ACL) injury increases risk for post traumatic knee osteoarthritis. ACL injury causes lack of knee stability and frequently requires ACL-reconstruction (ACLR) in order to restore functional and anatomical joint stability. Magnetic resonance imaging with T2 mapping sequence is used to quantify the amount of water content in articular cartilage hence; it is considered a better tool and more beneficial than radiographic based assessment in early detection even before being symptomatic. The aim of work is to estimate the incidence of subclinical degenerative changes that happened early in patients who underwent ACL reconstruction and to identify the correlations of T2 mapping values with patients' BMI, meniscal state/operations, ACL graft assessment and presence of ACLR related complications.

Results

The study was conducted upon 71 patients, divided into 61 anterior cruciate ligament reconstructed knees and 10 control cases using 1.5 T MRI. Assessment of cartilage sub-compartment T2 values and comparison with average normal cartilage T2 values obtained from the control group. Multiple correlations of the grade of articular cartilage degeneration within anterior cruciate ligament reconstructed knees with Body Mass Index (BMI), time of operation as well associated meniscal operations and anterior cruciate ligament graft complications.

Conclusions

Adding the T2 cartilage mapping sequence improves the ability to detect subclinical early degenerative articular cartilage changes in patients who underwent anterior cruciate ligament reconstruction, taking into consideration the relation of the patients' BMI, previous meniscal injuries/operation, ACL graft status and related graft complications with the T2 cartilage mapping values.

Quantitative MRI Biomarkers to Predict Risk of Reinjury Within 2 Years After Bridge-Enhanced ACL Restoration

BACKGROUND

Quantitative magnetic resonance imaging (qMRI) methods were developed to establish the integrity of healing anterior cruciate ligaments (ACLs) and grafts. Whether qMRI variables predict risk of reinjury is unknown.

PURPOSE

To determine if qMRI measures at 6 to 9 months after bridge-enhanced ACL restoration (BEAR) can predict the risk of revision surgery within 2 years of the index procedure.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Originally, 124 patients underwent ACL restoration as part of the BEAR I, BEAR II, and BEAR III prospective trials and had consented to undergo an MRI of the surgical knee 6 to 9 months after surgery. Only 1 participant was lost to follow-up, and 4 did not undergo MRI, leaving a total of 119 patients for this study. qMRI techniques were used to determine the mean cross-sectional area; normalized signal intensity; and a qMRI-based predicted failure load, which was calculated using a prespecified equation based on cross-sectional area and normalized signal intensity. Patient-reported outcomes (International Knee Documentation Committee subjective score), clinical measures (hamstring strength, quadriceps strength, and side-to-side knee laxity), and functional outcomes (single-leg hop) were also measured at 6 to 9 months after surgery. Univariate and multivariable analyses were performed to determine the odds ratios (ORs) for revision surgery based on the qMRI and non-imaging variables. Patient age and medial posterior tibial slope values were included as covariates.

RESULTS

In total, 119 patients (97%), with a median age of 17.6 years, underwent MRI between 6 and 9 months postoperatively. Sixteen of 119 patients (13%) required revision ACL surgery. In univariate analyses, higher International Knee Documentation Committee subjective score at 6 to 9 months postoperatively (OR = 1.66 per 10-point increase; P = .035) and lower qMRI-based predicted failure load (OR = 0.66 per 100-N increase; P = .014) were associated with increased risk of revision surgery. In the multivariable model, when adjusted for age and posterior tibial slope, the qMRI-based predicted failure load was the only significant predictor of revision surgery (OR = 0.71 per 100 N; P = .044).

CONCLUSION

Quantitative MRI-based predicted failure load of the healing ACL was a significant predictor of the risk of revision within 2 years after BEAR surgery. The current findings highlight the potential utility of early qMRI in the postoperative management of patients undergoing the BEAR procedure.

SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER) versus minimal intervention for young adults at risk of knee osteoarthritis after ACL reconstruction: SUPER-Knee randomised controlled trial protocol

INTRODUCTION

Anterior cruciate ligament injury and reconstruction (ACLR) is often associated with pain, functional loss, poor quality of life and accelerated knee osteoarthritis development. The effectiveness of interventions to enhance outcomes for those at high risk of early-onset osteoarthritis is unknown. This study will investigate if SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER) is superior to a minimal intervention control for improving pain, function and quality of life in young adults with ongoing symptoms following ACLR.

METHODS AND ANALYSIS

The SUPER-Knee Study is a parallel-group, assessor-blinded, randomised controlled trial. Following baseline assessment, 184 participants aged 18-40 years and 9-36 months post-ACLR with ongoing symptoms will be randomly allocated to one of two treatment groups (1:1 ratio). Ongoing symptoms will be defined as a mean score of <80/100 from four Knee injury and Osteoarthritis Outcome Score (KOOS₄) subscales covering pain, symptoms, function in sports and recreational activities and knee-related quality of life. Participants randomised to SUPER will receive a 4-month individualised, physiotherapist-supervised strengthening and neuromuscular programme with education. Participants randomised to minimal intervention (ie, control group) will receive a printed best-practice guide for completing neuromuscular and strengthening exercises following ACLR. The primary outcome will be change in the KOOS₄ from baseline to 4 months with a secondary endpoint at 12 months. Secondary outcomes include change in individual KOOS subscale scores, patient-perceived improvement, health-related quality of life, kinesiophobia, physical activity, thigh muscle strength, knee function and knee cartilage morphology (ie, lesions, thickness) and composition (T2 mapping) on MRI. Blinded intention-to-treat analyses will be performed. Findings will also inform cost-effectiveness analyses.

ETHICS AND DISSEMINATION

This study is approved by the La Trobe University and Alfred Hospital Ethics Committees. Results will be presented in peer-reviewed journals and at international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12620001164987.

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.

Neural Correlates of Self-Reported Knee Function in Individuals After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Anterior cruciate ligament (ACL) rupture is a common knee injury among athletes and physically active adults. Despite surgical reconstruction and extensive rehabilitation, reinjuries are common and disability levels are high, even years after therapy and return to activity. Prolonged knee dysfunction may result in part from unresolved neuromuscular deficits of the surrounding joint musculature in response to injury. Indeed, "upstream" neurological adaptations occurring after injury may explain these persistent functional deficits. Despite evidence for injury consequences extending beyond the joint to the nervous system, the link between neurophysiological impairments and patient-reported measures of knee function remains unclear.

HYPOTHESIS

Patterns of brain activation for knee control are related to measures of patient-reported knee function in individuals after ACL reconstruction (ACL-R).

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

In this multicenter, cross-sectional study, participants with unilateral ACL-R (n = 25; 10 men, 15 women) underwent task-based functional magnetic resonance imaging testing. Participants performed repeated cycles of open-chain knee flexion/extension. Neural activation patterns during the movement task were quantified using blood oxygen level-dependent (BOLD) signals. Regions of interest were generated using the Juelich Histological Brain Atlas. Pearson product-moment correlations were used to determine the relationship between mean BOLD signal within each brain region and self-reported knee function level, as measured by the International Knee Documentation Committee index. Partial correlations were also calculated after controlling for time from surgery and sex.

RESULTS

Patient-reported knee function was positively and moderately correlated with the ipsilateral secondary somatosensory cortex (r = 0.57, P = 0.005) and the ipsilateral supplementary motor area (r = 0.51, P = 0.01).

CONCLUSION

Increased ipsilateral secondary sensorimotor cortical activity is related to higher perceived knee function.

CLINICAL RELEVANCE

Central nervous system mechanisms for knee control are related to subjective levels of knee function after ACL-R. Increased neural activity may reflect central neuroplastic strategies to preserve knee functionality after traumatic injury.

High Levels of Satisfaction and Adequate Patient-Reported Outcomes After Operative Reconstruction of Multiligament Knee Injury With Allograft Among Patients Aged 40 Years and Older

Purpose

To describe injury characteristics and patient-reported outcomes (PROs) among patients aged 40 years and older who underwent allograft reconstruction for multiligament knee injury (MLKI).

Methods

Records of patients aged 40 years and older who underwent allograft multiligament knee reconstruction at a single institution between 2007 and 2017 with a minimum of 2 years of follow-up were retrospectively reviewed. Demographic information, concomitant injuries, patient satisfaction, and PROs including International Knee Documentation Committee and Marx activity scores were obtained.

Results

Twelve patients were included with a minimum follow-up time of 2.3 years (mean, 6.1; range, 2.3-10.1 years) and a mean age at surgery of 49.8 years. Seven patients were male, and the most common mechanism of injury was sport-related. The most frequently reconstructed MLKIs were anterior cruciate ligament and medial collateral ligament (4), anterior cruciate ligament and posterolateral corner (2), and posterior cruciate ligament and posterolateral corner (2). The majority of patients reported satisfaction with their treatment (11). Median International Knee Documentation Committee and Marx scores were 73 (interquartile range, 45.5-88.0) and 3 (interquartile range 0-5), respectively.

Conclusions

Patients aged 40 years and older can expect a high level of satisfaction and adequate PROs at 2-years follow-up after operative reconstruction for a MLKI with allograft. This demonstrates that allograft reconstruction for a MLKI in older patients may have clinical utility.

Level of Evidence

IV, therapeutic case series.

Clinical outcome and computer tomography based tunnel placement evaluation following arthroscopic anteromedial portal anterior cruciate ligament reconstruction in non-athletic population

BACKGROUND

The morphology of distal femur and proximal tibia varies between different ethnicities, and it can affect the tunnel dimensions and positions while doing ACL reconstruction which may affect the clinical outcome. There is limited data on the clinical outcome and CT based tunnel placement evaluation in femur and tibia of Indian nonathletic population.

METHODS

Thirty non-athletic patients with mean age of 25.50±6.9 years and ACL rupture who underwent single bundle hamstring autograft arthroscopic ACL reconstruction by anteromedial portal were included in the study. Their preoperative IKDC Score, Lysholm-Tegner score, Tegner activity level were calculated and knee stability was assessed clinically using anterior drawer test, Lachman test and pivot shift test. The CT scan of the operated knee was done once the complete extension of the knee was achieved. Using the multimodality workstation available at the department of radio-diagnosis the tunnel parameters of femoral and tibial tunnel was calculated. After 6 months the patients were reassessed for clinical and radiological outcome. The postoperative outcome was compared with preoperative outcome.

RESULTS

There was a significant difference in preoperative and postoperative score, the difference in IKDC score was 15.08 points, improvement of 14.65 points was seen in Lysholm-Tegner score and there was marked improvement in Tegner activity level. Tests for knee stability were normal in >90% of patients postoperatively. The CT evaluation showed that the femoral tunnels were positioned at 28.45%±3.69% (20.16%-38.35%) along the deep-shallow axis and 25.81%±3.819% (20.69%-37.35%), the mean tunnel obliquity compared to the femoral shaft axis were 47.34°±5.427° (37.68°-58.16°) in the coronal plane and 47.93°±7.023° (35.11°-63.95°), the mean tunnel length was 3.38 cm±0.331 cm (2.79 cm-4.18 cm). The tibial tunnel were positioned at 45.63%±5.832% (32.23%-58.23%) along the anterior-posterior axis and 47.70%±2.26% (42.40%-51.96%) along the medio-lateral axis. The tibial tunnel length was found to be 3.89 cm±0.519 cm (3.05 cm-5.06 cm).

CONCLUSION

This study helps to ascertain that the ACL reconstruction via anteromedial portal technique using femoral offset zig followed by postoperative home-based rehabilitation technique gives favorable clinical outcomes in Indian non-athletic patients. All patients had improvement in stability of knee after the surgery. The position of femoral tunnels was anatomical but in comparison to Caucasian patients its placement was deeper and higher. Hence, we conclude that the anteromedial portal technique of ACL reconstruction provides favorable clinical outcome and adequate anatomical tunnel placement in Indian non athletic patients.

Risk of Postoperative Stiffness Following Multiligamentous Knee Injury Surgery Is Not Affected by Obesity: A Multicenter Study

PURPOSE

The purpose of this study was to examine the relationship between obesity and postoperative stiffness following surgical management of multiligamentous knee injuries (MLKIs) using a large two-center cohort, by both 1) using binary cutoffs at various body mass indexes (BMIs) and 2) a linear regression model.

METHODS

190 consecutive patients who underwent surgical management of MLKIs between January 2001 and March 2020 were reviewed at two level 1 academic trauma centers. Patient demographics, surgical characteristics, and manipulation under anesthesia (MUA)/lysis of adhesions (LOA) were reviewed. Patients were stratified by obesity grades: grade 1 (BMI 30 to <35) grade 2 (BMI 35 to <40); grade 3 (BMI >40), and compared with a nonobese comparison group with BMI <30. Multivariate logistic regressions were performed, including the covariates of age, gender, BMI, acute versus chronic injury, external fixator, vascular injury, knee dislocation, and Schenck Classification. Fisher's exact test was used to compare rate of MUA between grades of obesity. Analyses were performed with R. Statistical significance was set at P < .05.

RESULTS

The mean BMI of the cohort was 29.2 kg/m². The mean overall follow-up was 27.2 ± 7.2 months (range: 14-142 months). There were 55 (29.1%) MUA procedures observed at a mean 3.77 ± 2.18 months (range: 1.8-9.7 months) after final MLKI surgery. No significant difference was found in BMI of patients who underwent a MUA compared to patients who did not (30.2 vs 28.8; P = .67). There was no significant difference in rate or time to MUA following MLKI surgery between groups, with logistic regression demonstrating no significance (P = .144). Use of external fixation at the index surgery (OR = 3.3 [95% CI: 2.2, 4.7; P < .0001]) and vascular injury (OR = 6.2 [95% CI: 1.8, 24.5; P = .005]) were found to be independent predictors for need for MUA.

CONCLUSION

No difference in risk for postoperative stiffness requiring MUA following surgery for MLKI was found based on BMI. At all BMI levels, there were no significant increase in need for postoperative MUA, suggesting at minimum a neutralizing effect of obesity on postoperative stiffness. In addition, patients with external fixator use and vascular injury at index surgery were found to be at significantly higher risk for postoperative stiffness requiring MUA following surgery for MLKI. Surgeons should be aware of the risk factors for arthrofibrosis when proceeding with surgical repair or reconstruction of two or more ligaments of the knee.

LEVEL OF EVIDENCE

III, multicenter retrospective cohort study.

Multi-vendor multi-site quantitative MRI analysis of cartilage degeneration 10 Years after anterior cruciate ligament reconstruction: MOON-MRI protocol and preliminary results

OBJECTIVE

To describe the protocol of a multi-vendor, multi-site quantitative MRI study for knee post-traumatic osteoarthritis (PTOA), and to present preliminary results of cartilage degeneration using MR T1ρ and T2 imaging 10 years after anterior cruciate ligament reconstruction (ACLR).

DESIGN

This study involves three sites and two MR platforms. The patients are from a nested cohort (termed as Onsite cohort) within the Multicenter Orthopaedic Outcomes Network (MOON) cohort 10 years after ACLR. Phantoms and controls were scanned for evaluating reproducibility. Cartilage was automatically segmented, and T1ρ and T2 were compared between operated, contralateral, and control knees.

RESULTS

Sixty-eight ACL-reconstructed patients and 20 healthy controls were included. In phantoms, the intra-site coefficients of variation (CVs) of repeated scans ranged 1.8-2.1% for T1ρ and 1.3-1.7% for T2. The inter-site CVs ranged 1.6-2.1% for T1ρ and 1.1-1.4% for T2. In human subjects, the intra-site scan/rescan CVs ranged 2.2-3.5% for T1ρ and 2.6-4.9% for T2 for the six major compartments. In patients, operated knees showed significantly higher T1ρ and T2 values mainly in medial femoral condyle, medial tibia and trochlear cartilage compared with contralateral knees, and showed significantly higer T1ρ and T2 values in all six compartments compared to healthy control knees. The patient contralateral knees showed higher T1ρ and T2 values mainly in the lateral femoral condyle, lateral tibia, trochlear, and patellar cartilage compared to healthy control knees.

CONCLUSION

A platform and workflow with rigorous quality control has been established for a multi-vendor multi-site quantitative MRI study in evaluating PTOA 10 years after ACLR. Our preliminary report suggests significant cartilage matrix changes in both operated and contralateral knees compared with healthy control knees.

Optimizing Use of Large Databases in Joint Arthroplasty and Orthopaedics

The potential users of "big data" need to consider many factors when choosing whether to use a large observational database for their research question and, if so, which database is the best fit for the scientific question. The first section of this paper, written by Dr. James A. Browne, provides a framework (who, what, where, when, and why?) to assess the critical elements that are included in a large database, which allows the user to determine if interrogation of the data is likely to answer the research question. The next section of this paper, written by Dr. Bryan Springer, focuses on the importance of having an a priori research question before deciding the best data source to answer the question; it also elaborates on the differences between administrative databases and clinical databases. The final section of the paper, written by Dr. Kurt P. Spindler, reviews the concepts of hypothesis-generating and hypothesis-testing studies and discusses in detail the differences, strengths, limitations, and appropriate uses of observational data versus randomized controlled trials.

Characterization of Cartilage Injury and Associated Treatment at the Time of Primary Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) tears with concomitant cartilage injuries resulting in ACL reconstruction (ACLR) with cartilaginous procedures are common in the young, high-demand population. The purpose of this study was to report and characterize cartilage treatments performed at the time of index ACLR reconstruction and to determine if those treatments are associated with revision surgery (of any kind) in the 4-year follow-up. We performed a consecutive series of active duty service members in the Military Health System Data Repository with ACLR with and without concomitant cartilage procedures done at military facilities between October 2008 and September 2011. Patients were continuously enrolled with no history of knee surgeries for 2 years prior to primary ACLR. ACLR failure was defined as revision ACLR within 4 years following the primary ACLR. Of the 2,735 primary ACLRs included in the study, 5.3% (143/2,735) underwent isolated ACLR with a cartilage procedure. Of these patients, 23.07% (33/143) experienced ACLR failure within 4 years after ACLR with cartilage procedures, including 33.33% (11/33) undergoing revision ACLR. We found concomitant cartilage procedures at time of index ACLR to have the following rates of revision 35.59% (21/59) for microfracture, 14.63% (6/41) for chondroplasty, and 13.95% (6/43) for osteochondral grafts. The overall clinical failure rate of service members with ACLR plus concomitant cartilage procedure is 23.07% with minimum 4-year follow-up. Further research should be done to identify modifiable demographic and surgical factors associated with failure. This is a retrospective case-control study that reflects level of evidence III.

Sex-Specific Changes in Physical Risk Factors for Anterior Cruciate Ligament Injury by Chronological Age and Stages of Growth and Maturation From 8 to 18 Years of Age

OBJECTIVE

To critically assess the literature focused on sex-specific trajectories in physical characteristics associated with anterior cruciate ligament (ACL) injury risk by age and maturational stage.

DATA SOURCES

PubMed, CINAHL, Scopus, and SPORTDiscus databases were searched through December 2021.

STUDY SELECTION

Longitudinal and cross-sectional studies of healthy 8- to 18-year-olds, stratified by sex and age or maturation on ≥1 measure of body composition, lower extremity strength, ACL size, joint laxity, knee-joint geometry, lower extremity alignment, balance, or lower extremity biomechanics were included.

DATA EXTRACTION

Extracted data included study design, participant characteristics, maturational metrics, and outcome measures. We used random-effects meta-analyses to examine sex differences in trajectory over time. For each variable, standardized differences in means between sexes were calculated.

DATA SYNTHESIS

The search yielded 216 primary and 22 secondary articles. Less fat-free mass, leg strength, and power and greater general joint laxity were evident in girls by 8 to 10 years of age and Tanner stage I. Sex differences in body composition, strength, power, general joint laxity, and balance were more evident by 11 to 13 years of age and when transitioning from the prepubertal to pubertal stages. Sex differences in ACL size (smaller in girls), anterior knee laxity and tibiofemoral angle (greater in girls), and higher-risk biomechanics (in girls) were observed at later ages and when transitioning from the pubertal to postpubertal stages. Inconsistent study designs and data reporting limited the number of included studies.

CONCLUSIONS

Critical gaps remain in our knowledge and highlight the need to improve our understanding of the relative timing and tempo of ACL risk factor development.

Latin American formal consensus on the appropriate indications of extra-articular lateral procedures in primary anterior cruciate ligament reconstruction

OBJECTIVES

To create a practice guideline for the appropriate indications of an extra-articular procedure in primary anterior cruciate ligament reconstruction (ACLR).

METHODS

The formal consensus method described by the Haute Autorité de Santé was used. The Latin American Society of Arthroscopy, Articular Replacement, and Sports Injuries (SLARD) recruited three groups of experts on ACLR. Initially, the steering group, consisting of eight surgeons, performed a systematic review of the literature and elaborated on 192 scenarios for primary ACLR. The rating group, composed of 23 surgeons, rated each scenario in two rounds, with an in-between in-person meeting for discussion. Median scores and agreement levels were estimated to classify each scenario as inappropriate, uncertain or appropriate for adding anterolateral reconstruction. Finally, the lecture group, consisting of 10 surgeons, revised each stage of the method, results and interpretation.

RESULTS

Of the scenarios, 11.97% were rated as appropriate for adding an extra-articular lateral procedure, 7.81% as inappropriate and 80.21% as uncertain. The key recommendations for the addition of extra-articular lateral techniques were as follows: it is appropriate when the patient is under 25 years of age, has high-grade physical examination findings, practises a pivoting sport and has hyperlaxity; meanwhile, it is inappropriate when the patient has low-grade physical examination findings, has normal laxity and does not practise a pivoting sport.

CONCLUSIONS

The appropriate indications of extra-articular lateral procedures in primary ACLR were determined on the basis of the best available evidence and expert opinion following a formal consensus method.

LEVEL OF EVIDENCE

V.

Lower rate of acceptable knee function in adolescents compared with young adults five years after acl reconstruction: results from the swedish national knee ligament register

Background

The number of studies with a large cohort of patients that primarily focus on patient-reported outcomes after ACL reconstruction in children and adolescents is limited. The purpose of the present study was to determine whether patient age affects the proportion of patients that achieve a patient-acceptable symptom state (PASS) on the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales one, two, five and 10 years after an ACL reconstruction.

Methods

The patient data in the present study were extracted from the Swedish National Knee Ligament Register (SNKLR). Patients aged between five and 35 years that underwent a primary ACL reconstruction between 1 January 2005 and 31 December 2017 and had completed the KOOS questionnaire at the one-, two-, five- or 10-year follow-up were included. A total of 2,848 patients met the inclusion criteria and were included in the study; 47 paediatric patients (females 5–13, males 5–15 years), 522 adolescents (females 14–19, males 16–19 years) and 2,279 young adults (females 20–35, males 20–35 years). The results from the KOOS were presented as the mean and 95% confidence interval (CI) for the mean. For comparisons between groups, the chi-square test was used for non-ordered categorical variables. For pairwise comparisons between groups, Fisher’s exact test (2-sided) was used for dichotomous variables. All the statistical analyses was set at 5%.

Results

Adolescents reported a significantly lower score than young adults on the KOOS4 at the two- (68.4 vs. 72.1; P < 0.05), five- (69.8 vs. 76.0; P < 0.05) and 10-year follow-ups (69.8 vs. 78.2; P < 0.05). Moreover, a significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults at the five-year follow-up (Symptoms: 83.3% vs. 91.6%; Pain: 42.9% vs. 55.3%; Function in daily living: 31.4% vs. 41.1%; Function in sports and recreational activities: 42.3% vs. 55.7%; Knee-related quality of life: 50.0% vs. 65.0%; P < 0.05).

Conclusions

A significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults five years after ACL reconstruction. The results of the present study provide important information for physicians and physiotherapists treating young patients after an ACL injury and they can aid in providing realistic expectations in terms of the mid- and long-term outcomes.

Level of evidence

Prospective Observational Register/Cohort Study, Level II.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05727-6.

Twenty-Year Outcomes After Anterior Cruciate Ligament Reconstruction: A Systematic Review of Prospectively Collected Data

BACKGROUND

Several long-term (≥20 years) follow-up studies after anterior cruciate ligament (ACL) reconstruction have been published in recent years, allowing for a systematic evaluation of outcomes.

PURPOSE

To summarize outcomes at ≥20 years after ACL reconstruction and identify patient and surgical factors that affect these results.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

Prospective studies of primary ACL reconstructions with hamstring or bone-patellar tendon-bone (BTB) autograft via an arthroscopic or a mini-open technique and with a mean follow-up of ≥20 years were identified. When possible, the mean scores for each outcome measure were calculated. Factors identified in individual studies as predictive of outcomes were described.

RESULTS

Five studies met the inclusion and exclusion criteria with a total of 2012 patients. The pooled mean follow-up for patient-reported outcome measures was 44.2% (range, 29.6%-92.7%) and in-person evaluation was 33.2% (range, 29.6%-48.9%). Four studies (n = 584) reported graft tears at a mean rate of 11.8% (range, 2%-18.5%) and 4 studies (n = 773) reported a contralateral ACL injury rate of 12.2% (range, 5.8%-30%). Repeat non-ACL arthroscopic surgery (4 studies; n = 177) to the ipsilateral knee occurred in 10.4% (range, 9.5%-18.3%) and knee arthroplasty (1 study; n = 217) in 5%. The pooled mean of the International Knee Documentation Committee subjective knee function (IKDC) score was 79.1 (SD, 21.8 [3 studies; n = 644]). In 2 studies (n?= 221), 57.5% of patients continued to participate in strenuous activities. The IKDC-objective score was normal or nearly normal in 82.3% (n = 496; 3 studies), with low rates of clinically significant residual laxity. Moderate-severe radiographic osteoarthritis (OA) (IKDC grade C or D) was present in 25.9% of patients (n = 605; 3 studies). Medial meniscectomy is associated with increased risk of radiographic OA. Radiographic OA severity is associated with worse patient-reported knee function, but the association with knee pain is unclear.

CONCLUSION

Currently available prospective evidence for ACL reconstruction with hamstring or BTB autograft provides several insights into outcomes at 20 years. The rates of follow-up at 20 years range from 30% to 93%. IKDC-objective scores were normal or nearly normal in 82% and the mean IKDC-subjective score was 79 points.

Operative Time Less Than 1.5 Hours, Male Sex, Dependent Functional Status, Presence of Dyspnea, and Reoperations Within 30 days Are Independent Risk Factors for Readmission After ACLR

Purpose

The purposes of this study are to use a large, patient-centered database to describe the 30-day readmission rate and to identify predictive risk factors for readmission after elective isolated ACLR.

Methods

The National Surgical Quality Improvement Program Database was retrospectively queried for isolated ACLR procedures between 2011 and 2017. Current Procedural Terminology (CPT) codes were used to identify isolated ACLR patients. Those undergoing additional procedures such as meniscectomy or multi-ligamentous reconstruction were excluded. Readmissions were analyzed against demographic variables with bivariate analysis. Multivariate logistic regression was used to find independent risk factors for 30-day readmissions after ACLR.

Results

A total of 11,060 patients (37.2% female) were included with an average age of 32.2 ± 10.6 years and mean body mass index (BMI) of 27.9 ± 6.5 kg/m² (29.2% were >30). The overall readmission rate was 0.59%. The most reported reason for readmission was infection 0.22 (24 out of 11,060). The following variables were associated with significantly higher readmission rates: male sex (P = .001), history of severe chronic obstructive pulmonary disease (COPD) (P = .025), cardiac comorbidity (P = .034), operative time >1.5 hours (P <.001), partially dependent functional health status (P = .002), high preoperative creatinine (P = .009), normal preoperative albumin (P = .020), hypertension (P = .034), and reoperations (P < .001). Operative time >1.5 hours, male sex, dependent functional status, the presence of dyspnea, and undergoing a reoperation were identified as independent risk factors for 30-day readmissions (P < .05 for all).

Conclusions

Isolated ACLR is associated with low 30-day readmission rates. Operative time >1.5 hours, male sex, dependent functional status, the presence of dyspnea, and 30-day reoperations are independent risk factors for readmission that should be considered in patient selection and addressed with preoperative counseling.

Level of Evidence

Level III, retrospective cohort study.

Patients Follow 3 Different Rate-of-Recovery Patterns After Anterior Cruciate Ligament Reconstruction Based on International Knee Documentation Committee Score

PURPOSE

To determine whether subgroups of patients exist based on the rate-of-recovery pattern of International Knee Documentation Committee (IKDC) scores after anterior cruciate ligament reconstruction (ACLR) and to determine clinical predictors for these subgroups.

METHODS

Patients who underwent primary or revision ACLR at a single institution from January 2014 to January 2019 were identified. Latent class growth analyses and growth mixture models (GMMs) with 1 to 6 classes were used to identify subgroups of patients based on functional rate-of-recovery patterns by use of preoperative, 1-year postoperative, and 2-year postoperative IKDC scores.

RESULTS

A total of 245 patients who underwent ACLR were included in the analysis. A 3-class GMM was chosen as the final model after 6 different models were run. Class 1, showing improvement from preoperatively to 1-year follow-up, with sustained improvement from 1 to 2 years postoperatively, constituted 77.1% of the study population (n = 189), whereas class 2, showing functional improvement between 1- and 2-year follow-up, was the smallest class, constituting 10.2% of the study population (n = 25), and class 3, showing slight improvement at 1-year follow-up, with a subsequent decline in IKDC scores between 1- and 2-year follow-up, constituted 12.7% of the study population (n = 31). Revision surgery (P = .005), a psychiatric history (P = .025), preoperative chronic knee pain (P = .024), and a subsequent knee injury within the follow-up period (P = .011) were the predictors of class 2 and class 3 rate-of-recovery patterns. Patient demographic characteristics, graft type, and concomitant ligament, meniscus, or cartilage injury at the time of surgery were not associated with the different recovery patterns described in this study.

CONCLUSIONS

Patients may follow different rate-of-recovery patterns after ACLR. By use of the GMMs, 3 different rate-of-recovery patterns based on IKDC scores were identified. Although most patients follow a more ideal rate-of-recovery pattern, fewer patients may follow less favorable patterns. Revision surgery, a history of psychiatric illness, preoperative chronic knee pain, and a subsequent knee injury within the follow-up period were predictive of less favorable rate-of-recovery patterns.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Animal models of osteoarthritis

Cite this article: Bone Joint Res 2022;11(8):514–517.

Do Patellar Tendon Repairs Have Better Outcomes than Quadriceps Tendon Repairs? A Prospective Cohort Analysis

Patellar tendon (PT) and quadriceps tendon (QT) ruptures represent significant injuries and warrant surgical intervention in most patients. Outcome data are predominantly retrospective analyses with low sample sizes. There are also minimal data comparing QT and PT repairs and the variables impacting patient outcomes. The level of evidence of the study is level II (prognosis). From the prospective OME cohort, 189 PT or QT repairs were performed between February 2015 and October 2019. Of these, 178 were successfully enrolled (94.2%) with 1-year follow-up on 141 (79.2%). Baseline demographic data included age, sex, race, BMI, years of education, smoking status, and baseline VR-12 MCS score. Surgical and follow-up data included surgeon volume, fixation technique, baseline, and 1-year Knee Injury and Osteoarthritis Outcome Score-Pain (KOOS-Pain), Knee Injury and Osteoarthritis Outcome Score-Physical Function (KOOS-PS), and 1-year Patient Acceptable Symptom State (PASS) scores and complications. Multivariable regression analysis was utilized to identify prognosis and significant risk factors for outcomes-specifically, whether KOOS-Pain or KOOS-PS were different between QT versus PT repairs. There were 59 patients in the PT cohort and 82 patients in QT cohort. Baseline demographic data demonstrated that PT cohort was younger (45.1 vs. 59.5 years, p <0.001), included significantly fewer patients of White race (51.7 vs. 80.0%, p = 0.001), lesser number of years of education (13.9 vs. 15.2 years, p = 0.020), a higher percentage of "high" surgeon volume (72.9% vs. 43.9%, p = 0.001) and 25.4% of PT repairs had supplemental fixation (QT had zero, p <0.001). Multivariable analysis identified gender (female-worse, p = 0.001), years of education (higher-better, p = 0.02), and baseline KOOS-Pain score (higher-better, p <0.001) as the risk factors that significantly predicted KOOS-Pain score. The risk factors that significantly predicted KOOS-PS were gender (female worse, p = 0.033), race (non-White-worse, p <0.001), baseline VR-12 MCS score (higher-better, p <0.001), and baseline KOOS-PS score (higher better, p = 0.029). KOOS-Pain and KOOS-PS scores improved after both QT and PT repairs. Patient reported pain and function at 1 year were similar between PT and QT repairs after adjusting for known risk factors. Multivariable analysis identified female gender and low baseline KOOS scores as predictors for worse outcomes.

Meniscal Tear Management Associated with ACL Reconstruction

Meniscal lesions often occur in association with anterior cruciate ligament (ACL) tears at the moment of the injury or, secondarily, as a consequence of knee instability. Both ACL and meniscus lesions are associated with a higher risk of osteoarthritis. Adequate treatment of these lesions reduces the rate of degenerative changes in the affected knee. Meniscal tears should be addressed concomitantly with ACL reconstruction and the treatment must be oriented towards preserving the meniscal tissue anytime this is possible. Several options for approaching a meniscus tear are available. The meniscal suture should always be considered, and, if possible, meniscectomy should be the last choice. “Masterly neglect” is a valuable option in selected cases.

Single-stage repair of displaced bucket-handle meniscal tears with anterior cruciate ligament reconstruction leads to good meniscal survivorship : a retrospective cohort study

AIMS

The best surgical strategy for the management of displaced bucket-handle (BH) meniscal tears in an anterior cruciate ligament (ACL)-deficient knee is unclear. Combining meniscal repair with ACL reconstruction (ACLR) is thought to improve meniscal healing rates; however, patients with displaced BH meniscal tears may lack extension. This leads some to advocate staged surgery to avoid postoperative stiffness and loss of range of motion (ROM) following ACLR.

METHODS

We reviewed the data for a consecutive series of 88 patients (mean age 27.1 years (15 to 49); 65 male (74%) and 23 female (26%)) who underwent single-stage repair of a displaced BH meniscal tear (67 medial (76%) and 21 lateral (24%)) with concomitant hamstring autograft ACLR. The patient-reported outcome measures (PROMs) EuroQol visual analogue scale (EQ-VAS), EuroQol five-dimension health questionnaire (EQ-5D), Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee score (IKDC), and Tegner score were recorded at final follow-up. A Kaplan-Meier survival analysis was performed to estimate meniscal repair survivorship. Analyses were performed with different cut-offs for meniscal and ACL injury-to-surgery time (within three weeks, three to ten weeks, and more than ten weeks).

RESULTS

Meniscal repair survivorship at a median final follow-up of 55 months (interquartile range (IQR) 24 to 91) was 82% (95% confidence interval 70 to 89). A total of 13 meniscus repairs failed (12 requiring meniscectomy and one requiring a further meniscal repair). At final follow-up, median PROMs were: EQ-VAS 85 (IQR 75 to 90), EQ-5D Index 0.84 (IQR 0.74 to 1.00), KOOS Pain 89 (IQR 80 to 94), KOOS Symptoms 82 (IQR 71 to 93), KOOS Activities of Daily Living 97 (IQR 91 to 100), KOOS Sport and Recreation 80 (IQR 65 to 90), KOOS Quality of Life 69 (IQR 53 to 86), IKDC 82.8 (IQR 67.8 to 90.8), and Tegner 6 (IQR 4 to 7). Two patients underwent revision ACLR following further injuries. One patient had an arthroscopic washout for infection at 11 days post-BH meniscal repair/ACLR. Four patients (4.5%) required a further procedure for stiffness, reduced ROM, and pain, and all were operated on within three weeks of meniscal injury. There was no difference in the interval between meniscal injury and surgery between repairs that failed and those that survived.

CONCLUSION

These data suggest that concomitant ACLR with repair of displaced BH meniscal tears, even if they have been displaced for some time, appears to afford satisfactory PROMs and good survivorship. Repairs within three weeks of meniscal injury may be associated with higher rates of postoperative reintervention for stiffness. Cite this article: Bone Joint J 2022;104-B(6):680-686.

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.