Chhabra, Anikar

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.

Background: Tendinopathies are common in middle-aged women. While estrogen regulates tendon remodeling, the influence of systemic hormone replacement therapy (HRT) on the risk of tendon degeneration remains unclear. Hypothesis/Purpose: The purpose of this study was to investigate the association between systemic HRT use and tendon injuries/repair in perimenopausal women. It was hypothesized that systemic HRT would be associated with an increased incidence of tendon injuries and repair. Study Design: Cohort study; Level of evidence, 4. Methods: Using the TriNetX Research Network, we identified female patients aged ≥45 years diagnosed with major tendon abnormalities, including rotator cuff tears, bicipital tendinitis, lateral or medial epicondylitis, Achilles tendinopathy, patellar tendinitis, or quadriceps strain, from January 2004 to July 2025. HRT exposure was defined as systemic estrogen and/or progestin use within 1 year before a diagnosis. Patients with contraindications to HRT were excluded. After 1:1 propensity score matching, 2 groups of 63,836 patients each were generated. Primary outcomes included diagnosis rates of specific tendon conditions; secondary outcomes were lifetime rates of corresponding tendon repair procedures. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The independent t test and chi-square test were used for analysis. Results: HRT users had significantly higher rates of several tendon abnormalities compared to matched controls, including rotator cuff tears (39.2% vs 37.9%, respectively; P < .001), bicipital tendinitis (13.3% vs 11.0%, respectively; P < .001), lateral epicondylitis (27.8% vs 22.7%, respectively; P < .001), and medial epicondylitis (6.8% vs 5.3%, respectively; P < .001). Achilles tendinopathy had similar rates between the 2 groups (14.6% vs 14.5%, respectively; P = .387). Surgical repair was more common in the HRT group, including biceps tendon repair/tenodesis (3.9% vs 3.3%, respectively; OR, 1.16 [95% CI, 1.10-1.23]; P < .001), rotator cuff repair (6.6% vs 6.2%, respectively; OR, 1.06 [95% CI, 1.01-1.11]; P = .013), and Achilles tendon repair (0.7% vs 0.6%, respectively; OR, 1.23 [95% CI, 1.06-1.41]; P = .005). Conclusion: Our study showed that systemic HRT use in women aged ≥45 years was associated with an increased risk of tendon injuries and a greater likelihood of surgical repair, although the absolute risk differences were modest. These findings underscore the need for awareness of the possible musculoskeletal effects of hormone therapy and highlight an underexplored area in women's orthopaedic health.

Abstract Osteochondral lesions of the knee, particularly in patients with early osteoarthritic changes, remain a clinical challenge. The Agili‐C implant (CartiHeal, Smith & Nephew), an aragonite‐based osteochondral scaffold, offers a single‐stage, off‐the‐shelf solution designed to regenerate both cartilage and subchondral bone. Unlike cell‐based therapies, Agili‐C eliminates the need for cell harvesting, culturing, or bioreactors, and avoids the morbidity associated with autografts and allografts. Recent multicenter randomized controlled trials have showed superior functional outcomes and pain reduction with Agili‐C compared to microfracture and debridement, even in patients with early osteoarthritis (Kellgren‐Lawrence grades 0‐3). This Technical Note describes the surgical technique for Agili‐C implantation and highlights key technical pearls to optimize outcomes.

Purpose To assess the ability of artificial intelligence (AI) to identify common sports‐related pathologies using radiologic imaging and to compare ChatGPT 4.0 with 2 competitors, Grok 2 and Claude 3.5 Sonnet. Methods ChatGPT 4.0, Grok 2, and Claude 3.5 Sonnet were used. Five common orthopaedic sports pathologies were chosen: anterior cruciate ligament tears, posterior cruciate ligament tears, meniscal tears, chondral pathologies, and rotator cuff tears. Fifty images representing each pathology were collected from a radiologic imaging database when possible, which included radiographic images, computed tomography, and magnetic resonance imaging. Normal images were collected that corresponded to each diagnostic category. Receiver operator characteristic curves and area under the curve values were calculated to assess the accuracy of each AI platform. Results ChatGPT 4.0, Grok 2, and Claude 3.5 Sonnet accurately identified the pathology in 23.6%, 15.7%, and 17.1% of diseased images, respectively. ChatGPT and Grok were most accurate at identifying meniscus pathologies (ChatGPT: 48%, Grok: 42%), whereas Claude Sonnet was most accurate at identifying anterior cruciate ligament pathologies (30%). The area under the curve for ChatGPT, Grok, and Claude Sonnet was 0.21, 0.16, and 0.15, respectively (ChatGPT 4.0 vs Grok 2, P = .30; ChatGPT 4.0 vs Claude 3.5 Sonnet, P = .24; Grok 2 vs Claude 3.5 Sonnet, P > .99). There were no differences in performance between the 3 platforms overall or within any of the diagnostic categories. Conclusions ChatGPT 4.0, Grok 2, and Claude 3.5 Sonnet correctly identified the pathology in less than 25% of images of common sports‐related pathologies and showed area under the curve values well below 0.5, indicating poor accuracy. Based on these findings, we do not recommend the current use of these generative AI models for image‐based diagnosis in orthopaedics. Clinical Relevance As the use of AI becomes more popular within the general public, it becomes increasingly important to make aware the capabilities and limitations of popular AI platforms in regard to their current image‐based diagnostic capabilities.

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.

Objectives: Tobacco use is a known modifiable risk factor for postoperative complications and revision surgery after anterior cruciate ligament reconstruction (ACLR). Prior studies focus on “tobacco” as a broad categorization of traditional cigarette smoking, smokeless tobacco, and other forms of nicotine use. It is unclear if differences in the type of nicotine used lead to similar adverse outcomes after ACLR. Thus, the purpose of this study was to (1) assess the incidence of postoperative complications among ACLR patients who use smokeless tobacco, and (2) compare these outcomes with those of patients who do not use tobacco and those who smoke cigarettes. Methods: A retrospective cohort study utilizing a large insurance database was conducted. Patients undergoing primary ACLR without concomitant knee procedures with a minimum 2-year follow-up were included. Smokeless tobacco only users, cigarette only users, and non-tobacco users were matched based on demographic variables and comorbidities. Postoperative complications within 90 days of surgery and subsequent knee surgery within 2 years were compared among groups. Multivariable logistic regressions were employed to control for confounding variables. Results: After applying exclusion criteria, there were 241,194 ALCR patients eligible for analysis. Of these, there were 898 (0.37%) patients that used smokeless tobacco only, 22,062 (9.1%) patients that exclusively used cigarettes, and 207,462 (86%) patients that did not use any tobacco products. Compared to non-users, smokeless tobacco users demonstrated increased risk of emergency department (ED) utilization (20.4% vs 8.7%, OR: 6.29; 95% CI: 3.70-10.9, p<0.001), pneumonia (1.2% vs 0.5%, OR: 3.36; 95% CI: 1.41-7.90, p=0.005), and acute kidney injury (AKI) (1.2% vs 0.1%, OR:12.7; 95% CI: 3.77-52.8, p<0.001) within 90 days of surgery. Additionally, smokeless tobacco users had a markedly increased risk of subsequent ACLR (13.5% vs 3.2%, OR: 4.75; 95% CI: 3.60-6.26, p<0.001) and meniscus surgery (12.9% vs 4.9%, OR: 2.89; 95% CI: 2.23-3.73, p<0.001) within 2 years compared to controls. When compared to cigarette smokers, smokeless tobacco users showed increased risk of ED visits (20.6% vs 19.3%, OR: 1.55; 95% CI: 1.25-1.90, p<0.001), pneumonia (1.2% vs 0.6%, OR: 3.25; 95% CI: 1.33-7.78, p=0.008), and AKI (1.3% vs 0.3%, OR: 7.63; 95% CI: 2.72-22.5, p<0.001) within 90 days. They also demonstrated a significantly increased risk of subsequent ACLR (13.4% vs 4.1%, OR: 4.81; 95% CI: 3.58-6.47, p<0.001) and meniscus surgery (12.8% vs 5.5%, OR: 2.45; 95% CI: 2.45-4.26, p<0.001) within 2 years when compared to cigarette smokers. Conclusions: Smokeless tobacco use was associated with increased risk of medical complications, ED utilization, and subsequent procedures compared to non-user controls and traditional smokers. These findings highlight the importance of considering specific forms of tobacco use in preoperative screening for patients undergoing ACLR.

Objective The aim of the study was to assess the interrater reliability between seven individuals assessing quadriceps femoris cross-sectional area, echo intensity, and corrected echo intensity. Design A retrospective subanalysis of data collected in a randomized controlled clinical trial (IRB 19-008473. NCT ID NCT04302558). Patients aged 13–50 yrs with an anterior cruciate ligament tear requiring surgical reconstruction were assessed for cross-sectional area of the rectus femoris, vastus intermedius, vastus lateralis, vastus medialis, and vastus medialis obliquis, and echo intensity of the rectus femoris. Musculoskeletal ultrasound imaging of the quadriceps was performed by one physical therapist, and quantitative assessments were performed by four physicians and three physical therapists. Results Physicians and physical therapists had good reliability for cross-sectional area of the rectus femoris (median interclass correlation 0.86 doctor of medicine (MD) and 0.84 physical therapist), cross-sectional area of the vastus medialis obliquis (0.82 and 0.82), and echo intensity mean (0.92 and 0.92). Rectus femoris cross-sectional area had the smallest coefficient of variation (26.512.7%), whereas subcutaneous fat had the largest coefficient of variation (93.3% left, 86.4% middle, 86.1% right). Conclusions These findings demonstrate reliability between physicians and physical therapists in interpretation of ultrasound images of the quadriceps. The inconsistency demonstrates the need for a consistent training across disciplines to ensure accurate image interpretation.

Background: Concussions have previously been shown to have persistent neurological changes represented by altered reaction time and postural stability in high-level athletes. The effects of concussions on professional basketball players’ performance and subsequent injuries during the 90 days after return to play (RTP) have not been investigated. Purpose/Hypothesis: the purpose of this study was to evaluate player statistical performance and risk of musculoskeletal (MSK) injury within 90 days of RTP from a diagnosed concussion. It was hypothesized that within the 90 days after RTP from a concussion, players would be at a greater risk for MSK injury with an associated decrease in player statistical performance. Study Design: Descriptive epidemiology study. Methods: Concussions sustained by National Basketball Association (NBA) players between the 2015-2016 and 2021-2022 seasons, excluding the 2019-2020 season, were evaluated using a publicly available database. The database was queried to identify any MSK injury in the 90-day post-RTP period after a concussion, along with time loss after subsequent injury. Performance statistics were obtained from each player’s preindex season and postindex season, as well as defined time points within the 90-day post-RTP period. Each concussed player was matched 1 to 1 with a nonconcussed control using position, win shares, player efficiency rating, and points per game. MSK injury incidence and player statistics in the concussion group were compared with controls using unpaired Student t tests. Results: A total of 70 concussions were identified in 70 professional basketball players and included in this analysis. A total of 49 players sustained an MSK injury in the 90-day post-RTP period (70%). Compared with controls, the odds of sustaining an MSK injury in the concussed cohort were 11.3 times greater (95% CI, 5.04-25.2; P < .001). Games missed after subsequent MSK injury were similar between the concussed and control groups ( P = .687). Comparisons over the 90-day post-RTP period did not reveal any significant changes in points per game, minutes per game, or true shooting percentage ( P > .05). When compared with controls, no changes in performance statistics were significantly different ( P > .05). Conclusion: Our analysis demonstrates that basketball players who sustain concussions are at a significantly increased risk for subsequent MSK injury within the 90-day post-RTP period but not player performance. Knowledge of this increased risk of MSK injury in concussed athletes can help guide concussion management for proper RTP and targeted rehabilitation in professional basketball players.

Background: Tobacco use is a known modifiable risk factor for postoperative complications and revision surgery after anterior cruciate ligament reconstruction (ACLR). Previous studies focus on tobacco as a broad categorization of traditional smoking, smokeless tobacco, and other forms of nicotine use. It is unclear if differences in the type of nicotine used lead to similar adverse outcomes after ACLR. Purposes: To (1) assess the incidence of postoperative complications among ACLR patients who use smokeless tobacco and (2) compare these outcomes with those of patients who do not use tobacco and those who smoke tobacco. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective cohort study utilizing the PearlDiver database was conducted. Patients undergoing primary ACLR with a minimum 2-year follow-up were included. Smokeless tobacco users (n = 898), cigarette smokers (n= 22,062), and non–tobacco users (n= 207,462) were matched based on patient variables and comorbidities. Postoperative complications within 90 days of surgery and subsequent knee surgery within 2 years were compared among groups. Multivariable logistic regressions were used to control for confounding variables. Results: Compared with nonusers, smokeless tobacco users demonstrated an increased risk of pneumonia (odds ratio [OR], 3.36; 95% CI, 1.41-7.90), acute kidney injury (OR, 12.7; 95% CI, 3.77-52.8), and emergency department (ED) utilization (OR, 6.29; 95% CI, 3.70-10.9) within 90 days of the ACLR. Additionally, smokeless tobacco users had an increased risk of ACLR (OR, 4.75; 95% CI, 3.60-6.26) and meniscal surgery (OR, 2.89; 95% CI, 2.23-3.73) within 2 years. When compared with cigarette smokers, smokeless tobacco users showed an increased risk of pneumonia (OR, 3.25; 95% CI, 1.33-7.78), acute kidney injury (OR, 7.63; 95% CI, 2.72-22.5), and ED visits (OR, 1.55; 95% CI, 1.26-1.90) within 90 days and subsequent ACLR (OR, 4.81; 95% CI, 3.58-6.47) and meniscal surgery (OR, 3.23; 95% CI, 2.45-4.26) within 2 years. Conclusion: Smokeless tobacco use was associated with an increased risk of medical complications, ED utilization, and subsequent procedures compared with nonuser controls and traditional smokers. These findings highlight the importance of considering specific forms of tobacco use in preoperative screening for patients undergoing ACLR.