Young age, female gender, Caucasian race, and workers' compensation claim are risk factors for reoperation following arthroscopic ACL reconstruction

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.

Workers' Compensation Patients Undergoing Hip Arthroscopy for Femoroacetabular Impingement Syndrome Experience Worse Mid-Term Outcomes but Similar Return-to-Work: A Propensity-Matched Analysis at 5-Year Follow-Up

PURPOSE

To investigate mid-term patient-reported outcomes (PROs) and return-to-work for workers' compensation (WC) patients undergoing primary hip arthroscopy (HA) for femoroacetabular impingement syndrome (FAIS) versus propensity-matched, non-WC controls and to determine whether achievement rates of minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) differ between these populations.

METHODS

A retrospective cohort study was conducted on WC patients who underwent primary HA for FAIS from 2012 to 2017. WC and non-WC patients were propensity matched on a 1:4 basis by sex, age, and body mass index (BMI). PROs were compared preoperatively and at 5 years postoperatively, employing the Hip Outcome Score Activities of Daily Living (HOS-ADL) and Sports-Specific (HOS-SS) subscales, modified Harris Hip Score (mHHS), 12-item international Hip Outcome Tool (iHOT-12), and visual analog scales (VAS) for pain and satisfaction. MCID and PASS were calculated using published thresholds for these measures. Preoperative and postoperative radiographs and the presence and timing of return to unrestricted work were evaluated.

RESULTS

Forty-three WC patients were successfully matched to 172 non-WC controls and followed for 64.2 ± 7.7 months. WC patients demonstrated lower preoperative scores for all measures (P ≤ .031) and worse HOS-ADL, HOS-SS, and VAS pain scores at 5-year follow-up (P ≤ .021). There were no differences in MCID achievement rates or magnitude of change between preoperative and 5-year postoperative PROs (P ≥ .093); however, WC patients achieved PASS at lower rates for HOS-ADL and HOS-SS (P ≤ .009). 76.7% of WC and 84.3% of non-WC patients returned to work without restrictions (P = .302) at 7.4 ± 4.4 versus 5.0 ± 3.8 months, respectively (P < .001).

CONCLUSIONS

WC patients undergoing HA for FAIS report worse preoperative pain and function than non-WC patients and experience worse pain, function, and PASS achievement at 5-year follow-up. However, they demonstrate similar MCID achievement and magnitude improvement between preoperative and 5-year postoperative PROs, and return to work without restrictions at a similar rate to non-WC patients, although they may take longer to do so.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level II.

After Anterior Cruciate Ligament Injury, Patients With Medicaid Insurance Experience Delayed Care and Worse Clinical Outcomes Than Patients With Non-Medicaid Insurance

Purpose

To evaluate the effects of socioeconomic factors on the operative treatment of anterior cruciate ligament injuries and outcomes following surgical reconstruction.

Methods

A retrospective cohort study of primary anterior cruciate ligament reconstruction surgeries at a single institution performed from 2011 to 2015 with minimum 2-year follow-up was conducted. Patient demographics, insurance type, workers' compensation status, surgical variables, International Knee Documentation Committee score, and failure were recorded from chart review. Education level and income were obtained via phone interview. Differences between functional outcome were compared between Medicaid and non-Medicaid groups.

Results

In total, 268 patients were included in the analysis (43 patients in the Medicaid group and 225 patients in the non-Medicaid group, overall mean follow-up of 3.1 ± 0.8 years). The Medicaid group demonstrated lower annual income (P < .001) and a lower level of completed education compared with the non-Medicaid group (P < .001). Patients who received Medicaid had a greater duration between time of initial knee injury and surgery compared with the those in non-Medicaid group (11.8 ± 16.3 months vs 6.1 ± 16.5 months, P < .001). At the time of follow-up, patients in the non-Medicaid group had a significantly greater International Knee Documentation Committee score compared with patients who received Medicaid (82.5 ± 13.8 vs 75.3 ± 20.8, P = .036).

Conclusions

Patients with Medicaid insurance were seen in the clinic significantly later after initial injury and had worse outcomes compared with patients with other insurance types. Also, patients in higher annual income brackets had significantly better clinical outcomes scores at a minimum of 2 years postoperatively.

Level of Evidence

Level III, retrospective cohort study.

Risk Factors for Revision or Rerupture After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

BACKGROUND

The rerupture or need for revision after anterior cruciate ligament reconstruction (ACLR) is a serious complication. Preventive strategies that target the early identification of risk factors are important to reduce the incidence of additional surgery.

PURPOSE

To perform a systematic review and meta-analysis to investigate risk factors for revision or rerupture after ACLR.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

Literature searches were performed in PubMed, Embase, and Web of Science from database inception to November 2021 and updated in January 2022. Quantitative, original studies reporting potential adjusted risk factors were included. Odds ratios (ORs) were calculated for potential risk factors.

RESULTS

A total of 71 studies across 13 countries with a total sample size of 629,120 met the inclusion criteria. Fifteen factors were associated with an increase in the risk of revision or rerupture after ACLR: male sex (OR, 1.27; 95% CI, 1.14-1.41), younger age (OR, 1.07; 95% CI, 1.05-1.08), lower body mass index (BMI) (OR, 1.03; 95% CI, 1.00-1.06), family history (OR, 2.47; 95% CI, 1.50-4.08), White race (OR, 1.32; 95% CI, 1.08-1.60), higher posterolateral tibial slope (OR, 1.15; 95% CI, 1.05-1.26), preoperative high-grade anterior knee laxity (OR, 2.30; 95% CI, 1.46-3.64), higher baseline Marx activity level (OR, 1.07; 95% CI, 1.02-1.13), return to a high activity level/sport (OR, 2.03; 95% CI, 1.15-3.57), an ACLR within less than a year after injury (OR, 2.05; 95% CI, 1.81-2.32), a concomitant medial collateral ligament (MCL) injury (OR, 1.62; 95% CI, 1.31-2.00), an anteromedial portal or transportal technique (OR, 1.36; 95% CI, 1.22-1.51), hamstring tendon (HT) autografts (vs bone-patellar tendon-bone [BPTB] autografts) (OR, 1.60; 95% CI, 1.40-1.82), allografts (OR, 2.63; 95% CI, 1.65-4.19), and smaller graft diameter (OR, 1.21; 95% CI, 1.05-1.38). The other factors failed to show an association with an increased risk of revision or rerupture after ACLR.

CONCLUSION

Male sex, younger age, lower BMI, family history, White race, higher posterolateral tibial slope, preoperative high-grade anterior knee laxity, higher baseline Marx activity level, return to a high activity level/sport, an ACLR within less than a year from injury, a concomitant MCL injury, an anteromedial portal or transportal technique, HT autografts (vs BPTB autografts), allografts, and smaller graft diameter may increase the risk of revision or rerupture after ACLR. Raising awareness and implementing effective preventions/interventions for risk factors are priorities for clinical practitioners to reduce the incidence of revision or rerupture after ACLR.

Incidence and risk factors for revision and contralateral anterior cruciate ligament reconstruction: A population-based retrospective cohort study

There is a limited data on epidemiology of primary and recurrent anterior cruciate ligament reconstruction (ACLR) in Canada. The objectives of this study were to examine the incidence and factors associated with recurrent ACLR (revision and contralateral ACLR) in a western Canadian province of Alberta. We conducted a retrospective cohort study with an average follow up of 5.7 years. Albertans aged 10 to 60 years with a history of primary ACLR between 2010/11 to 2015/16 were included in the study. Participants were followed up until March 2019 to observe outcomes: Ipsilateral revision ACLR and contralateral ACLR. Kaplan Meir approach was used to estimate event free survival and Cox proportional hazard regression analysis was conducted to identify associated factors. Of the total participants with a history of primary ACLR on a single knee (n = 9292), n = 359, 3.9% (95% confidence interval: 3.5-4.3) underwent a revision ACLR. A similar proportion among those having primary ACLR on either knee (n = 9676), n = 344, 3.6% (95% confidence interval: 3.2-3.9) underwent a contralateral primary ACLR. Young age (<30 years) was associated with increased risk of contralateral ACLR. Similarly, young age (<30 years), having initial primary ACLR in winter and having allograft were associated with a risk of revision ACLR. Clinicians can use these findings in their clinical practice and designing rehabilitation plans as well as to educate patients about their risk for recurrent anterior cruciate ligament tear and graft failure.

Failure modes after anterior cruciate ligament reconstruction: a systematic review and meta-analysis

PURPOSE

The reason for graft failure after anterior cruciate ligament reconstruction (ACLR) is multifactorial. Controversies remain regarding the predominant factor and incidence of failure aetiology in the literature. This review aimed to provide a meta-analysis of the literature to evaluate the relative proportion of various failure modes among patients with ACLR failure.

METHODS

The PubMed, Embase, Cochrane Library, Web of Science, and EBSCO databases were searched for literature on ACLR failure or revision from 1975 to 2021. Data related to causes for ACLR surgical failure were extracted, and a random effects model was used to pool the results, which incorporates potential heterogeneity. Failure modes were compared between different populations, research methods, graft types, femoral portal techniques, and fixation methods by subgroup analysis or linear regression. Funnel plots were used to identify publication bias and small-study effects.

RESULTS

A total of 39 studies were analyzed, including 33 cohort studies and six registry-based studies reporting 6578 failures. The results showed that among patients with ACLR failure or revision, traumatic reinjury was the most common failure mode with a rate of 40% (95% CI: 35-44%), followed by technical error (34%, 95% CI: 28-42%) and biological failure (11%, 95% CI: 7-15%). Femoral tunnel malposition was the most common cause of the technical error (29%, 95% CI: 18-41%), with more than two times higher occurrence than tibial tunnel malposition (11%, 95% CI: 6-16%). Traumatic reinjury was the most common factor for ACLR failure in European populations and in recent studies, while technical errors were more common in Asian populations, earlier studies, and surgery performed using the transtibial (TT) portal technique. Biological factors were more likely to result in ACLR failure in hamstring (HT) autografts compared to bone-patellar tendon-bone (BPTB) autografts.

CONCLUSION

Trauma is the most important factor leading to surgical failure or revision following ACLR. Technical error is also an important contributing factor, with femoral tunnel malposition being the leading cause of error resulting in failure.

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.

Evaluating a Digital Mental Health Intervention (Wysa) for Workers' Compensation Claimants: Pilot Feasibility Study

OBJECTIVE

This study examines the feasibility and acceptability of an AI-led digital mental health intervention in a Workers' Compensation (WC) program, Wysa for Return to Work.

METHODS

Self-reported demographic data and responses to psychosocial screening questions were analyzed alongside participants' app usage through which four key outcomes were measured: recruitment rate, onboarding rate, retention, and engagement.

RESULTS

The data demonstrated a high need for psychosocial interventions among injured workers, especially women, young adults, and those with high severity injuries. Those with more psychosocial risk factors had a higher rate of onboarding, retention, and engagement, and those with severe injuries had higher retention.

CONCLUSIONS

Our study concluded that Wysa for Return to Work, the AI-led digital mental health intervention that delivers a recovery program using a digital conversational agent, is feasible and acceptable for a return-to-work population.

Surgeon's experience, sports participation and a concomitant MCL injury increase the use of patellar and quadriceps tendon grafts in primary ACL reconstruction: a nationwide registry study of 39,964 surgeries

PURPOSE

To investigate the influence of surgeon-related factors and clinic routines on autograft choice in primary anterior cruciate ligament reconstruction (ACLR).

METHODS

Data from the Swedish National Knee Ligament Registry (SNKLR), 2008-2019, were used to study autograft choice (hamstring; HT, patellar; PT, or quadriceps tendon; QT) in primary ACLR. Patient/injury characteristics (sex, age at surgery, activity at time of injury and associated injuries) and surgeon-/clinic-related factors (operating volume, caseload and graft type use) were analyzed. Surgeon/clinic volume was divided into tertiles (low-, mid- and high-volume categories). Multivariable logistic regression was performed to assess variables influencing autograft choice in 2015-2019, presented as the odds ratio (OR) with a 95% confidence interval (CI).

RESULTS

39,964 primary ACLRs performed by 299 knee surgeons in 91 clinics were included. Most patients received HT (93.7%), followed by PT (4.2%) and QT (2.1%) grafts. Patients were mostly operated on by high-volume (> 28 ACLRs/year) surgeons (68.1%), surgeons with a caseload of ≥ 50 ACLRs (85.1%) and surgeons with the ability to use ≥ two autograft types (85.9%) (all p < 0.001). Most patients underwent ACLR at high-volume (> 55 ACLRs/year) clinics (72.2%) and at clinics capable of using ≥ two autograft types (93.1%) (both p < 0.001). Significantly increased odds of receiving PT/QT autografts were found for ACLR by surgeons with a caseload of ≥ 50 ACLRs (OR 1.41, 95% CI 1.11-1.79), but also for injury during handball (OR 1.31, 95% CI 1.02-1.67), various other pivoting sports (basketball, hockey, rugby and American football) (OR 1.59, 95% CI 1.24-2.03) and a concomitant medial collateral ligament (MCL) injury (OR 4.93, 95% CI 4.18-5.80). In contrast, female sex (OR 0.87, 95% CI 0.77-0.97), injury during floorball (OR 0.71, 95% CI 0.55-0.91) and ACLR by mid-volume relative to high-volume surgeons (OR 0.62, 95% CI 0.53-0.73) had significantly reduced odds of receiving PT/QT autografts.

CONCLUSION

An HT autograft was used in the vast majority of cases, but PT/QT autografts were used more frequently by experienced surgeons. Prior research has demonstrated significant differences in autograft characteristics. For this reason, patients might benefit if surgery is performed by more experienced surgeons.

LEVEL OF EVIDENCE

Level III.

Explosive hamstrings strength asymmetry persists despite maximal hamstring strength recovery following anterior cruciate ligament reconstruction using hamstring tendon autografts

PURPOSE

To investigate the differences in maximal (isometric and concentric peak torque) and explosive (rate of torque development (RTD)) hamstring and quadriceps strength symmetry between males and females during early- and late-phase rehabilitation after anterior cruciate ligament reconstruction (ACLR) using hamstring tendon (HT) autografts and to determine the interaction of time and sex on maximal and explosive strength symmetry.

METHODS

A total of 38 female and 51 male participants were assessed during early (3-6 months post-operative) and late (7-12 months post-operative) phases of rehabilitation following ACLR. Maximal (concentric and isometric peak torque) and explosive (isometric RTD) hamstring and quadriceps strength were assessed and presented as limb symmetry index (LSI).

RESULTS

Maximal concentric hamstrings asymmetry (Early: 86 ± 14; Late 92 ± 13; p = 0.005) as well as maximal concentric (Early, 73 ± 15; Late 91 ± 12; p < 0.001) and explosive (Early: 82 ± 30; Late: 92 ± 25; p = 0.03) quadriceps asymmetry decreased from early to late rehabilitation. However, there were no significant changes in maximal isometric quadriceps strength and explosive isometric hamstring strength in the same time period. Females had a larger asymmetry in maximal concentric (Females: 75 ± 17; Males: 81 ± 15; p = 0.001) and explosive (Females: 81 ± 32; Males: 89 ± 25; p = 0.01) quadriceps strength than males throughout rehabilitation. There were no sex differences in maximal and explosive hamstring strength. There were no sex by time interactions for any variables.

CONCLUSION

Explosive hamstring strength asymmetry did not improve despite recovery of maximal hamstring strength during rehabilitation following ACLR with HT autografts. While sex did not influence strength recovery, females had larger maximal and explosive quadriceps strength asymmetry compared to males throughout rehabilitation following ACLR.

LEVEL OF EVIDENCE

Level III.

Workers' Compensation Patients Improved After Hip Arthroscopy for Labral Tears: A 5-Year Outcome Propensity Score-Matched Study

BACKGROUND

The workers' compensation (WC) status has been associated with inferior outcomes in orthopaedic procedures and is usually excluded from clinical outcome studies. Therefore, comparative studies based on WC status are scarce.

PURPOSE

(1) To determine outcomes of patients with WC claims treated with hip arthroscopy for labral tears at a minimum 5-year follow-up and (2) to compare these findings with a propensity score-matched control group without WC claims.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients were propensity score matched to a control group without WC claims. Data were prospectively collected for all patients undergoing hip arthroscopy. Patients were included if they received primary hip arthroscopy for labral tears in the setting of femoroacetabular impingement, had a WC claim, and had preoperative and minimum 5-year follow-up patient-reported outcomes ([PROs]; modified Harris Hip Score [mHHS], Non-Arthritic Hip Score [NAHS], Hip Outcome Score-Sports Specific Subscale [HOS-SSS], and visual analog scale [VAS] for pain). Clinical outcomes were measured using the Patient Acceptable Symptom State (PASS), minimal clinically important difference (MCID), and maximum outcome improvement satisfaction threshold (MOI).

RESULTS

A total of 111 from 132 (84.1%) eligible WC patients met the inclusion criteria with an average follow-up time of 80.3 ± 37.3 months. WC cases demonstrated significant improvement from preoperatively to a minimum 5-year follow-up for mHHS, NAHS, HOS-SSS, and VAS for pain (P < .05). WC patients returned to work at a 66% rate, with an average clearance time of 4.7 months to light duty and 9.5 months to heavy duty. When compared with the control group, the WC group demonstrated lower pre- and postoperative PROs (P < .05); however, WC cases had a greater magnitude of improvement (ΔmHHS [P = .0012], ΔNAHS [P < .001], and ΔHOS-SSS [P = .012]). Rates of achieving MCID and MOI were similar in both groups (P > .05). The WC group went on to receive a future arthroscopy in 19 cases (17.1%), while 10 cases (4.5%) in the control group required revision arthroscopy (P < .001). Patients in both the WC and the control groups converted to total hip arthroplasty at similar rates (13.3% and 15.4%, respectively; P > .05).

CONCLUSION

Patients with WC claims treated with hip arthroscopic surgery showed significant improvement and high rates of returning to work at a minimum 5-year follow-up. Although having lower scores in PROs and achieving PASS rates, no differences were found in MCID and MOI rates. Furthermore, WC patients had a greater magnitude of improvement from preoperatively to a minimum 5-year follow-up after hip arthroscopy. Therefore, even though more studies are needed to determine the causes of inconsistent outcomes in the WC population, hip arthroscopy can effectively treat labral tears in the setting of femoroacetabular impingement, regardless of the WC status.

Minimizing the risk of graft failure after anterior cruciate ligament reconstruction in athletes. A narrative review of the current evidence

Anterior cruciate ligament (ACL) tear is one of the most common sport-related injuries and the request for ACL reconstructions is increasing nowadays. Unfortunately, ACL graft failures are reported in up to 34.2% in athletes, representing a traumatic and career-threatening event. It can be convenient to understand the various risk factors for ACL failure, in order to properly inform the patients about the expected outcomes and to minimize the chance of poor results. In literature, a multitude of studies have been performed on the failure risks after ACL reconstruction, but the huge amount of data may generate much confusion.The aim of this review is to resume the data collected from literature on the risk of graft failure after ACL reconstruction in athletes, focusing on the following three key points: individuate the predisposing factors to ACL reconstruction failure, analyze surgical aspects which may have significant impact on outcomes, highlight the current criteria regarding safe return to sport after ACL reconstruction.

Social Determinants of Health Influence Access to Care and Outcomes in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To investigate the impact social determinants of health (SDOH) have on accessing orthopaedic treatment after an anterior cruciate ligament injury, as well as patient-reported and surgical outcomes after anterior cruciate ligament reconstruction (ACLR).

METHODS

A systematic search of the PubMed, MEDLINE, Epub Ahead of Print, Embase, and Web of Science databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies that reported at least 1 SDOH and its effect on patient-reported outcomes or surgical outcomes after anterior cruciate ligament reconstruction. Our search identified 937 studies. After eliminating 273 duplicates, 2 authors screened 664 articles on the basis of title and abstract. After this initial screening, 76 studies were evaluated for data extraction. Studies were categorized based on the social determinant(s) of health reported.

RESULTS

Twenty-two articles published between 2002 and 2020 were included in this study, encompassing 15 retrospective cohort studies, 3 prospective cohort studies, 3 cross-sectional studies, and 1 case-control study from 9 journals across 3 countries. Of these articles, 9 investigated race/ethnicity, 8 investigated insurance status, 4 investigated income, 5 investigated education level, 2 investigated employment status, and 5 investigated socioeconomic status. Reported outcomes included time to treatment, concomitant knee injury, patient-reported outcome measurement scores, postoperative complications, need for additional surgery, and postoperative healthcare utilization.

CONCLUSIONS

Certain SDOH, including black race, Hispanic ethnicity, public health insurance, and lower socioeconomic status contribute to a delay in access to care, which may result in increased severity of concomitant knee injuries encountered at the time of anterior cruciate ligament reconstruction and inferior outcomes.

STUDY DESIGN

Level III, systematic review of level I-III evidence.

Disparities in ACL Reconstruction: the Influence of Gender and Race on Incidence, Treatment, and Outcomes

PURPOSE OF REVIEW

Anterior cruciate ligament (ACL) rupture is a common injury that has important clinical and economic implications. We aimed to review the literature to identify gender, racial and ethnic disparities in incidence, treatment, and outcomes of ACL injury.

RECENT FINDINGS

Females are at increased risk for ACL injury compared to males. Intrinsic differences such as increased quadriceps angle and increased posterior tibial slope may be contributing factors. Despite lower rates of injury, males undergo ACL reconstruction (ACLR) more frequently. There is conflicting evidence regarding gender differences in graft failure and ACL revision rates, but males demonstrate higher return to sport (RTS) rates. Females report worse functional outcome scores and have worse biomechanical metrics following ACLR. Direct evidence of racial and ethnic disparities is limited, but present. White athletes have greater risk of ACL injury compared to Black athletes. Non-White and Spanish-speaking patients are less likely to undergo ACLR after ACL tear. Black and Hispanic youth have greater surgical delay to ACLR, increased risk for loss to clinical follow-up, and less physical therapy sessions, thereby leading to greater deficits in knee extensor strength during rehabilitation. Hispanic and Black patients also have greater risk for hospital admission after ACLR, though this disparity is improving. Females have higher rates of ACL injury with inconclusive evidence on anatomic predisposition and ACL failure rate differences between genders. Recent literature has suggested inferior RTS and functional outcomes following ACLR in females. Though there is limited and mixed data on incidence and outcome differences between races and ethnic groups, recent studies suggest there may be disparities in those who undergo ACLR and time to treatment.

The Minimally Clinically Important Difference and Substantial Clinical Benefit in Anterior Cruciate Ligament Reconstruction: A Time-to-Achievement Analysis

This study examined the time-dependent course of the minimally clinically important difference (MCID) and the substantial clinical benefit (SCB) achievement for International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales following anterior cruciate ligament reconstruction (ACLR). A prospective institutional registry was queried for patients receiving ACLR. The patient-reported outcome measures (PROMs) of interest included the IKDC score and KOOS sub-scales. One hundred forty-three patients (mean±SD age, 30.86±12.78 years; mean±SD body mass index, 25.51±4.64 kg/m²) were included in the analysis. Threshold values for the MCID/SCB were 18.9 of 29.6 on IKDC score, 15.7 of 25.3 on KOOS Symptom, 11.9 of 15.5 on KOOS Pain, 13.3 of 20.0 on KOOS ADL, 25.9 of 35.8 on KOOS Quality of Life (QoL), and 27.0 of 43.0 on KOOS Sport (area under the curve, 0.74-0.91). Overall, MCID achievement rates increased from 28.0% to 42.7% at 6 months to 41.9% to 70.8% at 12 months. Achievement rates of SCB increased from 16.1% to 30.4% at 6 months to 29.3% to 51.8% at 12 months. Statistically significant increases in MCID achievement (chi-square=47.95-79.36, all P<.001) and SCB achievement (chi-square=26.02-53.24, all P<.001) occurred from preoperative to 6-month time points across PROMs. From 6-month to 12-month time points, increases in MCID achievement occurred on IKDC score and KOOS QoL (chi-square=5.53-15.11, P<.001-.009). Statistically significant increases in MCID and SCB achievement occurred from preoperative to 6-month time points across IKDC score and KOOS subscales; however, statistically significant increases in achievement rates from 6 months to 1 year occurred on IKDC score, KOOS QoL, and KOOS Sport. This study underlines the importance of considering psychological factors and rehabilitative milestones when examining the achievement MCID and SCB after ACLR. [Orthopedics. 2021;44(5):299-305.].

Female gender and medial meniscal lesions are associated with increased pain and symptoms following anterior cruciate ligament reconstruction in patients aged over 50 years

PURPOSE

Several studies report satisfactory clinical outcomes following ACLR in older patients, but none evaluated the effects of meniscal and cartilage lesions. The aim was to evaluate the influence of meniscal and cartilage lesions on outcomes of ACLR in patients aged over 50 years.

METHODS

The authors prospectively collected records of 228 patients that underwent primary ACLR, including demographics, time from injury to surgery, whether injuries were work related, and sports level (competitive, recreational, or none). At a minimum follow-up of 6 months, knee injury and osteoarthritis outcome scores (KOOS), International Knee Documentation Committee (IKDC) score and Tegner activity level were recorded, and differential laxity was measured as the side-to-side difference in anterior tibial translation (ATT) using instrumented laximetry devices. Regression analyses were performed to determine associations between outcomes and meniscal and cartilage lesions as well as nine independent variables.

RESULTS

A total of 228 patients aged 54.8 ± 4.3 years at index ACLR were assessed at a follow-up of 14.3 ± 3.8 months. KOOS subcomponents were 85 ± 13 for symptoms, 91 ± 10 for pain, 75 ± 18 for daily activities, 76 ± 18 for sport, and 88 ± 12 for quality of life (QoL). The IKDC score was A for 84 (37%) knees, B for 96 (42%) knees, C for 29 (13%) knees, and D for 8 (4%) knees. Tegner scores showed a decrease (median 0, range -4 to 4) and differential laxity also decreased (median - 4, range - 23.5 to 6.0). KOOS symptoms worsened with higher BMI (p = 0.038), for women (p = 0.007) and for knees that had medial meniscectomy (p = 0.029). KOOS pain worsened with higher BMI (p ≤ 0.001), for women (p = 0.002) and for knees with untreated (p = 0.047) or sutured (p = 0.041) medial meniscal lesions. Differential laxity increased with follow-up (p = 0.024) and in knees with lateral cartilage lesions (p = 0.031).

CONCLUSION

In primary ACLR for patients aged over 50 years, female gender and medial meniscal lesions significantly compromised KOOS symptoms and pain, while lateral cartilage lesions significantly increased differential laxity. Compared to knees with an intact medial meniscus, those with sutured or untreated medial meniscal lesions had worse pain, while those in which the medial meniscus was resected had worse symptoms. These findings are clinically relevant as they could help surgeons with patient selection and adjusting expectations according to their functional demands.

LEVEL OF EVIDENCE

III.

Effect of Leg Dominance on Medium- to Long-Term Functional Outcomes, Quality of Life, and Revision Rates After Isolated ACL Reconstruction

Background:

The effect of leg dominance on short-term functional outcomes and return to sports after arthroscopic anterior cruciate ligament reconstruction (ACLR) has been evaluated. However, postoperative medium- to long-term recovery and revision rates are not well known.

Purpose:

To investigate whether leg dominance affects medium- to long-term clinical and functional scores and revision rates after ACLR.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included in this study were 235 patients (205 male and 30 female) who underwent isolated arthroscopic ACLR. Patients were divided according to the leg dominance status of their injured limb into 2 groups: dominant leg injured (120 patients) and nondominant leg injured (115 patients). Preoperative and postoperative functional outcomes and health-related quality of life (HRQoL) were evaluated using the visual analog scale for pain, Tegner activity scale, Lysholm knee score, International Knee Documentation Committee (IKDC) subjective knee evaluation form, 36-Item Short Form Health Survey (SF-36), and overall patient satisfaction. Moreover, the revision rates of the 2 groups were compared according to leg dominance, patient characteristics, and operative features.

Results:

The mean follow-up period was 8.0 ± 2.3 years (range, 5-13 years). A significant preoperative to postoperative improvement in range of motion and functional scores was noticed in both groups (P < .001 for all). However, the improvement was significantly higher in the dominant leg group for the Tegner (P = .001), Lysholm (P = .006), and IKDC (P < .001) scores as well as for the SF-36 domain scores for general health (P = .009), social role (P = .048), and emotional role (P = .032). Also, patient satisfaction was significantly higher in the dominant leg group (P = .007). The dominant leg group was associated with a lower revision rate compared with the nondominant leg group (5.8% vs 15.7%, respectively; P = .015).

Conclusion:

High recovery rates were seen after arthroscopic ACLR, regardless of leg dominance. However, leg dominance had a significant effect on postoperative medium- to long-term functional outcomes, HRQoL, and revision rates.

Greater knee joint laxity remains in teenagers after anatomical double-bundle anterior cruciate ligament reconstruction compared to young adults

PURPOSE

There is paucity in studies regarding double-bundle anterior cruciate ligament reconstruction (DB-ACLR) in teenagers. The purpose of this study is to investigate clinical outcome after DB-ACLR and analyze whether any differences exist between teenagers and young adults.

METHODS

A retrospective study was performed between 2009 and 2017. Teenagers were defined as patients between 15 and 19 years and young adults between 20 and 25 years old. Isolated anterior cruciate ligament (ACL) injuries with DB-ACLR with minimum two-year follow up were included. Pre and post-operative Lysholm score, Tegner activity scale, KT-2000 arthrometer, manual pivot-shift grade, were assessed with post-operative one-leg hop test, isokinetic knee extensor strength test at 60°/sec, International Knee Documentation Committee Score (IKDC score), and re-injury rate.

RESULTS

One-hundred and thirty-one patients, 75 patients in the teenage group (Group A) and 56 patients in the young adult group (Group B), were enrolled. Lysholm score was significantly lower in Group A (89.6 ± 21.1) compared to Group B (95.9 ± 4.6) (p = 0.04). Side to side difference in KT-2000 arthrometer (2.3 ± 2.2 mm vs 1.0 ± 2.3 mm, Group A vs Group B, respectively, p < 0.01) and ratio of post-operative positive pivot shift was significantly greater in Group A (30.7%) compared to Group B (7.1%) (p < 0.01). No significant difference was seen in re-injury rate (n.s.).

CONCLUSION

Teenage patients have a greater tendency for residual knee joint laxity after DB-ACLR. Although teenagers and patients in the early twenties are close in age, characteristic in knee joint laxity may be different and, therefore, may require attention upon surgery and post-operative follow-up.

LEVEL OF EVIDENCE

III.