Background: Matching techniques such as direct covariate matching and propensity score matching (PSM) are increasingly used in anterior cruciate ligament reconstruction (ACLR) research to reduce bias in observational study designs. However, the rationale for covariate selection, consistency in methodological reporting, and patterns of matching practices remain unclear. Purpose: To systematically evaluate covariate matching practices in ACLR literature, including the types and number of covariates used, methodological transparency, and trends in matching strategies. Study Design: Systematic review. Methods: A systematic literature search of the PubMed, EMBASE, and Cochrane databases was conducted to evaluate covariate matching practices in the ACLR literature. A comprehensive search identified 798 unique studies, of which 97 met eligibility criteria. Data were extracted on study design, matching technique, covariate inclusion, reporting practices, and matching ratios. Descriptive and comparative statistics were used to summarize trends. Results: The 97 included studies encompassed 91,165 ACLRs. Most studies were retrospective (90.7%) and cohort in design (92.8%). PSM was used in 41 studies (42.3%), while 56 (57.7%) used direct matching. A total of 60 unique covariates were used across 76 different combinations. PSM studies used significantly more covariates than direct matching studies (6.17 ± 2.79 vs 3.75 ± 1.63; P < .0001), and database studies used more covariates than single-center studies (6.33 ± 2.89 vs 4.08 ± 1.96; P < .0001). The most commonly used covariates were age (96.9%), sex (84.5%), and body mass index (41.2%). Only 6 studies (6.2%) provided justification for covariate selection. The most frequent matching ratio was 1:1 (73.2%). While most studies reported descriptive statistics after matching (95.9%), only 10.3% did so before matching, and 13.4% failed to report prematching sample size. Conclusion: Matching practices in ACLR studies remain highly variable, with limited justification provided for covariate selection. PSM and database-based studies tend to incorporate a greater number of covariates, yet reporting of matching methodology is often inconsistent. To enhance the quality, reproducibility, and comparability of ACLR research, future studies should adopt standardized reporting practices for matching, including explicit descriptions of covariate selection, matching algorithms, balance diagnostics, and match ratios. These steps can serve as a foundation for a more unified research framework, enabling future studies to collectively generate higher quality, generalizable evidence for ACLR outcomes.
Adding a Lateral Extra‐articular Tenodesis to Quadriceps Autograft Anterior Cruciate Ligament Reconstruction Reduces Risk of Graft Failure
Purpose The purpose of this study was to compare graft failure and clinical outcomes following primary anterior cruciate ligament reconstruction (ACLR) using quadriceps tendon autograft (QA), with or without a modified Lemaire lateral extra‐articular tenodesis (LET). Methods Patients with ACL deficiency who underwent primary QA ACLR with or without LET and completed at least 2‐year follow‐up were included. Patients with a Beighton score ≥4, a preoperative pivot shift grade ≥2, or an intention to return to cutting and pivoting sports were offered LET. The primary outcome variable assessed was graft failure as defined by graft rupture or grade ≥2 pivot shift at any point postoperatively. Secondary outcomes included return to sport clearance rates, the International Knee Documentation Committee and Lysholm scores and postoperative complications. Results There were 122 undergoing QA ACLR with LET (QA + LET group) and 152 undergoing isolated QA ACLR (QA group). The QA + LET group had a significantly lower failure rate of 14.8% versus 29.6% in the QA group ( P = .02). In addition, the QA + LET group had a lower residual pivot shift rate compared with the QA group (11.3% vs. 26.3% respectively; P = .01). There was no difference in graft retear rates between the 2 groups ( P = .37). The QA + LET returned to sport significantly faster at 8.8 months compared with 9.7 months in the QA group ( P = .038). Conclusions The addition of LET to QA ACLR was associated with a significantly lower overall graft failure rate and lower percentage of patients with residual pivot shifts after ACLR compared with QA alone at 2‐year follow up. However, there was no difference between the 2 groups with regard to graft retear rates. The addition of an LET to QA ACLR also allowed athletes to return to sports faster compared with QA alone. Level of Evidence Level III, retrospective comparative study.
Arthroscopic Bone Graft Remplissage Using Flexible Bone Allograft for Treatment of Hill‐Sachs Lesions in Anterior Shoulder Instability
Hill‐Sachs lesions are defects in the posterior humeral head from anterior glenoid impaction during dislocation. Left untreated, they can contribute to failure after arthroscopic Bankart repair. Arthroscopic remplissage, involving capsulotenodesis of the posterior capsule and infraspinatus tendon, is the most frequently performed approach to address this lesion. In this technical note, we describe a bone graft remplissage that augments the remplissage with the arthroscopic insertion of a flexible bone graft between the capsule and the sutures to fill the Hill‐Sachs defect. Once secured, the graft is compressed into the defect to create a biological scaffold. This technique combines the simplicity of the knotless remplissage technique with the addition of structural bone graft to Hill‐Sachs lesions.
Rotator Cuff Repair Augmentation With an Autograft Biceps Patch, the “Biceps Smash,” Results in Low Retear Rates at 6 Months and Promising Clinical Outcomes at 12 Months
Purpose To evaluate retear rates, clinical outcomes, and complications of a consecutive series of full‐thickness rotator cuff repair cases augmented with an autograft biceps patch. Methods A retrospective review was performed of patients undergoing rotator cuff repair with autograft biceps patch augmentation. Patients underwent either magnetic resonance imaging or ultrasound to evaluate rotator cuff repair integrity at a minimum of 6 months postoperatively. Patient‐reported outcomes including the American Shoulder and Elbow Surgeons Score and Single Assessment Numeric Evaluation score were also collected and evaluated for clinical significance at a minimum of 12 months postoperatively. Analysis of retear rates was performed by comparing observed retear rates to expected retear rates using the modified Rotator Cuff Healing Index score. Results The final cohort included 25 rotator cuff repair cases. Postoperative imaging was obtained by magnetic resonance imaging in 22 patients at a mean of 9 months postoperatively (range, 6.0‐15.3 months) and ultrasound in 3 patients at a mean of 30.4 months (range, 28.8‐32.2 months). The expected retear rate using the modified Rotator Cuff Healing Index score was 21.5% for the entire cohort. There was 1 retear, resulting in an actual retear rate of 4% at an average of 23.5‐month follow‐up ( P = .0196). The average Single Assessment Numeric Evaluation score was 93 (standard deviation 9), and the average American Shoulder and Elbow Surgeons Score was 96 (standard deviation 6.3) at an average of 23.5‐month follow‐up (range 14‐32). Patient acceptable symptomatic state was achieved by 96% of the cohort for the American Shoulder and Elbow Surgeons Score and 88% of the cohort for the Single Assessment Numeric Evaluation score. There were no cases of reoperation or complications. Conclusions In this consecutive series, the biceps autograft “smash” patch for rotator cuff augmentation resulted in a low rate of retears, favorable patient‐reported outcomes, and no complications. This augmentation option has the potential to be safe and effective for improving rotator cuff repair healing rates. Level of Evidence Level IV, retrospective case series.
Body Mass Index ≥45 Is Associated With an Increased Risk of Health Care Utilization and Long-term Complications After Total Ankle Arthroplasty
Background: The impact of obesity on outcomes following total ankle arthroplasty (TAA) remains unclear, with existing literature reporting mixed results. Although some studies have identified obesity as a risk factor for perioperative complications and poor clinical outcomes, others have found no significant association. Thus, the purpose of this study was to evaluate the association between obesity, across a range of body mass index (BMI) classifications, and postoperative complications after TAA. Methods: Patients undergoing primary TAA were identified from a large national insurance database. Individuals with a BMI ≥30 were identified and matched 1:1 to nonobese controls using propensity score matching based on demographics and comorbidities. Obese patients were further stratified into BMI categories: 30-34.9, 35-39.9, 40-44.9, and ≥45. Ninety-day complications and 2-, 5-, and 10-year surgery-specific outcomes were assessed. Odds ratios (ORs) with 95% CIs and Kaplan-Meier survival analyses were used to evaluate complication risks. Results: After matching, 3364 patients were included in each cohort. No significant differences in 90-day complication rates were observed for patients with BMI 30-44.9 compared with controls. Patients with BMI ≥45 had increased risk of surgical site infection (OR 2.21, 95% CI 1.29-3.79, P = .003), emergency department visits (OR 1.43, 95% CI 1.04-1.96, P = .025), and readmissions (OR 2.31, 95% CI 1.47-3.63, P < .001). The pooled 90-day complication rate was significantly higher in this group as well (12.9% vs 7.6%, OR 1.77, 95% CI 1.26-2.48, P < .001). At 10-year follow-up, Kaplan-Meier analysis demonstrated that patients with a BMI ≥45 had a higher risk of periprosthetic joint infection (PJI compared with controls (hazard ratio 1.75, 95% CI 1.07-2.85, P = .03). Patients with BMI 30-34.9 had a significantly lower risk of aseptic loosening at both 5 years (OR 0.68, 95% CI 0.49-0.94, P = .019) and 10 years (OR 0.65, 95% CI 0.48-0.88, P = .005). Conclusion: BMI ≥45 was associated with higher all-cause health care utilization, including emergency department visits and hospital readmissions, as well as higher long-term risk of PJI following TAA. Level of Evidence: Level III, retrospective cohort study.
Preoperative Knee Bone Marrow Edema Is Associated With Poor Clinical Outcomes Following Posterior Medial Meniscal Root Repair
Purpose To determine if preoperative femoral or tibial bone marrow edema (BME) is indicative of higher rates of re‐tear and conversion to total knee arthroplasty (TKA) after posterior medial meniscal root tear repair, and, secondarily, whether preoperative BME impacted patient‐reported outcome measures and rates of infection and arthrofibrosis. Methods Patients that underwent posterior medial meniscal root tear repair between 2013 and 2021 with a 2‐year minimum follow‐up were retrospectively analyzed. Primary outcome measures included re‐tears and TKA conversion. Secondary outcomes included International Knee Documentation Committee (IKDC) score and Lysholm score, infection, and arthrofibrosis. Cohort‐specific minimally clinically important difference and Patient Acceptable Symptomatic Scale rates were calculated. Two‐tailed t‐tests, Wilcoxon rank‐sum tests, and Fisher's exact tests were used where appropriate. Results The study population consisted of 97 knees (74 without BME [NBME], 23 with BME) with average follow‐up of 38.9 months (24‐68). Preoperatively, the NBME group had higher IKDC scores ( P = .008). Postoperatively, the NBME group had higher IKDC scores at 6 months, 1 year, and 2 years (84.5 [6.0] vs 68.5 [11.0]) ( P = .041, <.001, <.001). IKDC minimally clinically important difference rates were not significantly different between groups at all follow‐ups. Patient Acceptable Symptomatic Scale rates were higher for the NBME group at 1‐year and final follow‐up (100.0% vs 60.9%) ( P < .001 for both). Lysholm scores were higher for the NBME group at 1‐year and final follow‐up (84.0 [5.6] vs 74.6 [12.8]) ( P = .019 and .008, respectively). Re‐tear occurred in 17.4% of the BME group and 0% of the NBME group ( P = .003). TKA conversion rates were 21.7% in the BME group and 2.7% in the NBME group ( P = .008). There was no difference in arthrofibrosis or infection rates. Conclusions Preoperative BME in patients undergoing posterior medial meniscal root tear repair is associated with higher rates of recurrent meniscal root tearing and conversion to TKA in addition to lower subjective IKDC and Lysholm scores compared to patients without preoperative BME. Level of Evidence Level III, retrospective prognostic case control series.
Incidence, Risk Factors, and Reasons for Emergency Department Utilization 90 Days After Achilles Tendon Repair
Background: Postoperative emergency department (ED) utilization significantly reduces patient satisfaction and increases health care spending. Purpose: To identify the incidence, risk factors, and reasons for ED visits within 90 days of Achilles tendon repair (ATR). Study Design: Case-control study; Level of evidence, 3 Methods: This study utilized the PearlDiver database to identify all instances of primary ATR. Patient age, sex, Elixhauser comorbidity index (ECI), region, and insurance coverage were extracted. The incidence, timing, and primary diagnoses for those with an ED visit 90 days post-ATR were extracted. Also, the 90-day total cost was determined and compared for those with and without a postoperative ED visit. Welch t test and Pearson chi-square test were used to determine significant differences between groups. Multivariable logistic regressions were used to determine risk factors associated with ED utilization after ATR. Results: Of the 82,604 patients with an ATR identified in the database, 6939 (8.4%) had ≥1 ED visit. Of ED visits, 1506 (21.7%) occurred in the first week after ATR and 3587 (51.7%) occurred in the first 4 weeks after ATR. The mean 90-day cost for those with an ED visit was significantly greater than those without an ED visit ($7330 ± $13,383 vs $3515 ± $5787; P < .001). Independent risk factors associated with ED utilization within 90 days were younger age (odds ratio [OR], 1.02; P < .001), female sex (OR, 1.26; P < .001), higher ECI (OR, 1.17; P < .001), a history of tobacco use (OR, 1.57; P < .001), and having Medicaid insurance (OR, 1.73; P < .001). Most ED visits within the first 2 weeks after ATR were for surgical-site pain (53.6%), with 62.4% of diagnoses being directly related to the surgical site. After 2 weeks following ATR, pain persisted as the most common reason for ED utilization (20.9%). Conclusion: More than 8% of patients had ≥1 ED visit within 90 days of ATR, with over half occurring in the first 4 weeks. This markedly increased health care spending. Addressing regional disparities, improving Medicaid acceptance policies, and enhancing perioperative care plans, such as multimodal pain management and addressing the psychological aspects of pain, may reduce the incidence and economic burden of postoperative ED visits.
Age, Workload, and Usage Rate: Risk Factors Associated With Knee Injuries in Women’s National Basketball Association Athletes
Background: Knee injuries are among the most common injuries in female basketball players. Despite the growing popularity of professional women's basketball, particularly the Women's National Basketball Association (WNBA), there are limited recent data evaluating the incidence of and risk factors for knee injuries in WNBA athletes. Hypothesis: Older age, minutes played per game, number of games played, and player usage rate would be significantly associated with having a knee injury in WNBA players from the 2017 to 2022 seasons. Study Design: Descriptive epidemiology study. Methods: Publicly available data on the injury history and player records of active WNBA players between the 2017 and 2022 seasons were reviewed to identify players with a knee injury resulting in ≥1 games missed. The primary outcome was the incidence of knee injuries reported per 1000 minutes-exposures (MEs). Player demographics, statistics, and injury characteristics were recorded. Secondary analysis was conducted using bivariate and multivariable logistic regression to investigate risk factors associated with having a knee injury. Results: A total of 87 players (10.8% of all players) sustained a combined 104 knee injuries between the 2017 and 2022 seasons, indicating a rate of 6.03 knee injuries per 1000 MEs. Accounting for potential confounders, having a knee injury was significantly associated with older age (OR, 1.11; 95% CI, 1.05-1.18; P = .0002) and higher usage rate (OR, 1.06; 95% CI, 1.02-1.11; P = .02). Conclusion: This study showed that knee injuries occurred in 10.8% of players, with an overall rate of 6.03 injuries per 1000 MEs. The most significant risk factors associated with having a knee injury in WNBA athletes were older age and higher player usage rate. Implementing targeted load management strategies for players with higher usage rates or advanced age may help reduce the incidence of knee injuries among female basketball athletes.
Diagnostic Arthroscopy for Identifying Patellofemoral Chondral Lesions Missed by MRI in Pediatric Patients Undergoing MPFLR
Background: Patellofemoral dislocations are often associated with chondral injuries. In adults, diagnostic arthroscopy (DA) has identified chondral injuries in up to one-third of cases where magnetic resonance imaging (MRI) was negative. However, the value of DA in detecting cartilage injuries in pediatric patients undergoing medial patellofemoral ligament reconstruction (MPFLR) has not been well studied. Purposes: To evaluate the utility of DA in diagnosing cartilaginous injuries in pediatric patients undergoing MPFLR with negative preoperative MRI findings and to compare postoperative outcomes between patients with and without chondral injury findings on DA. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: A retrospective review was conducted on patients aged 0 to 18 years who underwent combined MPFLR and DA procedures from 2015 to 2023 at a single institution. The exclusion criteria were as follows: revision MPFLR; tibial tubercle osteotomy; multiligament reconstructions; and previous meniscal injury. MRI and DA reports were reviewed for chondral findings. Patients were classified into 3 groups: +MRI/+DA, –MRI/+DA, and –MRI/–DA. Subgroup analysis was performed within the –MRI/+DA group to compare outcomes in the immediate postoperative recovery period between those who underwent a chondroplasty versus those who did not. Results: Of the 155 patients included, follow-up averaged 7.8 months (median, 5 months [range, 0-41 months]). Among 89 patients with negative MRI findings, 39 (43.8%) had chondral injuries detected on DA. Targeted treatment was performed in 22 (56.4%) of these patients, a lower rate than in those with positive MRI findings (80.3%; P = .02). No significant differences were observed in knee flexion at 2 weeks postoperatively: +MRI/+DA (77.9°± 23°), –MRI/+DA (66.5°± 30.2°), and –MRI/–DA (73.3°± 30°) ( P = .14). Similarly, no significant differences were found at 12 weeks: +MRI/+DA (135.3°± 13°), –MRI/+DA (127.8°± 21°), and –MRI/–DA (134.1°± 13.4°) ( P = .10). Range of motion and complication rates were comparable across all groups ( P > .05). A subgroup analysis in the –MRI/+DA cohort comparing patients who underwent an arthroscopic procedure (n = 22) with those who did not (n = 17) showed no significant differences in range of motion or complication rates ( P > .05). Conclusion: Diagnostic arthroscopy detected cartilaginous injuries in 43.8% of pediatric patients with negative preoperative MRI undergoing MPFLR. This highlights the diagnostic value of DA in identifying injuries that would otherwise remain undetected.
Cartilage Scaffolds Implanted Without Subchondral Drilling Are Associated With Improved Outcomes and Fewer Complications Compared to Scaffolds Implanted With Subchondral Drilling in the Treatment of Isolated Patellar Cartilage Lesions
Purpose To compare clinical outcomes between augmented subchondral drilling (aSCD) and nonsubchondral drilling (NoSCD) techniques, both using a cartilage scaffold, in the treatment of isolated patellar cartilage lesions. Methods A retrospective cohort study was conducted on patients who underwent surgical treatment for isolated patellar cartilage using either an aSCD technique (a subchondral drilling augmented with a particulated cartilage allograft scaffold or a flexible osteochondral allograft scaffold) or a NoSCD technique (a particulated juvenile articular cartilage scaffold or a flexible osteochondral allograft scaffold implanted without performing a subchondral drilling). Patients were included if they had a minimum 2‐year follow‐up and excluded if they underwent concomitant meniscal or ligamentous procedures. While tibial tubercle osteotomy (TTO) was commonly performed, it was not a strict inclusion criterion. All procedures were performed through arthrotomy with a standardized postoperative rehabilitation protocol. Clinical outcomes included International Knee Documentation Committee (IKDC) and Lysholm scores, reoperation rates, conversion to total knee arthroplasty, and complications. Results A total of 65 knees were included: 31 in the aSCD group and 34 in the NoSCD group, with a mean follow‐up of 50.4 months (range, 24‐88 months). In the aSCD group, particulated allograft cartilage hydrated with platelet‐rich plasma was used in 80.7% of cases and flexible osteochondral allograft in 19.3%, while the NoSCD group was treated with Cartiform (Arthrex) in 70.6% and particulated juvenile articular cartilage in 29.4% of cases. TTO was performed in 87.0% of aSCD and 91.2% of NoSCD cases. Average defect sizes were 3.7 cm 2 (aSCD) and 4.0 cm 2 (NoSCD). At final follow‐up, the NoSCD group had significantly better outcomes, with higher median IKDC scores (81.0 vs 74.0; P < .001) and median Lysholm scores (83.0 vs 77.0; P < .001). A significantly greater proportion of NoSCD patients exceeded the minimal clinically important difference for IKDC (100% vs 80.6%; P = .024) but not for Lysholm (97.1% vs 93.5%; P = .935) at final follow‐up. In multivariable regression adjusting for scaffold type, TTO, and defect size, aSCD remained a significant independent predictor of lower final IKDC (β = –8.97; P = .001) and Lysholm (β = –12.71; P < .001) scores. The aSCD group had a significantly higher rate of repeat surgery (45.2% vs 14.7%; P = .015). There was no significant difference in conversion to total knee arthroplasty between groups ( P = .432). Conclusions For the treatment of isolated patellar cartilage lesions, a nonsubchondral drilling technique with scaffolding was associated with improved patient‐reported outcomes and fewer complications compared to a subchondral drilling technique with scaffolding, although there was no difference in the rate of conversion to total knee arthroplasty. Level of Evidence Level III, retrospective comparative study.