Background: Several special tests for detecting medial ulnar collateral ligament (MUCL) injuries of the elbow have been described, but data on the clinical utility of these tests are limited. Purpose: To determine the clinical utility of selected elbow special tests to detect MUCL injuries in an athletic population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 84 consecutive patients with sports-related elbow pain underwent a standardized clinical examination. Overall, 6 special tests (moving valgus stress test, static valgus stress test, modified valgus stress test, milking maneuver, pronation flexion resistance test, and temple/cheek press test) were performed. Sensitivity, specificity, accuracy, positive/negative predictive value, and positive/negative likelihood ratio (LR+ and LR–, respectively) were calculated for individual tests and combinations of tests to detect MUCL injuries. Higher values for the LR+ and lower values for the LR– represent stronger clinical utility. Results: For detecting MUCL injuries, the moving valgus stress test resulted in the highest sensitivity (98%) and accuracy (93%) with the lowest LR– (2%). The milking maneuver had the highest LR+ (5.1) with the second highest sensitivity (77%) and accuracy (79%). The pronation flexion resistance test and the temple/cheek press test had the lowest LR+ (1.5 and 1.8, respectively) and highest LR– (94% and 95%, respectively) in addition to the lowest sensitivity (16% and 9%, respectively) and accuracy (33% and 30%, respectively). No combination of tests resulted in increased clinical utility. Conclusion: The moving valgus stress test and milking maneuver demonstrated acceptable clinical utility in which the moving valgus stress test was better for ruling out MUCL injuries and the milking maneuver was better at ruling in MUCL injuries. There was no added value when combining the 2 tests together or with other maneuvers.
Meniscal Repair in the Setting of Revision Anterior Cruciate Ligament Reconstruction: 6-Year Follow-up Results From the MARS Cohort
Background: Meniscal preservation has been demonstrated to contribute to long-term knee health and has been a successful intervention in isolation and in patients with anterior cruciate ligament reconstruction (ACLR). The long-term results of meniscal repair in the setting of revision ACLR have yet to be documented. Purpose: To report the incidence of meniscal repair failures at the 6-year follow-up in a cohort of patients who underwent concurrent revision ACLR and primary meniscal repair. Study Design: Prospective cohort study; Level of evidence, 2. Methods: All revision ACLRs with concomitant primary meniscal repair cases from a multicenter group between 2006 and 2011 were selected. Six-year follow-up was obtained to determine whether any subsequent surgery had occurred since their initial revision ACLR. If so, operative reports were obtained, whenever possible, to verify pathological condition and treatment. Results: In total, 221 patients from 1234 revision ACLRs underwent concurrent primary meniscal repairs (18% of the cohort). There were 238 repairs performed: 173 medial and 65 lateral. The majority of these repairs (n = 181; 76%) were performed with an all-inside technique. Six-year surgical follow-up was obtained in 77% (171/221) of the cohort, or 189 of 238 (79%) of the repairs (136 medial, 53 lateral). The meniscal repair failure rate, defined as reoperation, was 16% (31/189) at 6 years. Of the 31 failures, 28 were medial (24 all-inside, 4 inside-out; 28/136 = 20.6% failure rate) and 3 were lateral (2 all-inside, 1 inside-out; 3/53 = 5.7% failure rate). Three medial failures were treated in conjunction with a subsequent repeat revision ACLR. Medial tears underwent reoperation for failure at a significantly higher rate than lateral tears (20.6% vs 5.7%; P = .01) and had a significantly shorter survival time compared with lateral tears ( P = .02). No difference was found between the failure and nonfailure groups when it came to tear type, tear length, repair technique utilized, suture/implant type, or number of sutures used between the 2 groups. Conclusion: Meniscal repair in the revision ACLR setting has a 16% failure rate at 6 years. Failure rates for medial tears (20.6%) were found to be higher than that for lateral tears (5.7%), which aligns with previous studies in both the revision and primary ACLR setting.
A Novel Machine Learning Model to Predict Revision ACL Reconstruction Failure in the MARS Cohort
Background: As machine learning becomes increasingly utilized in orthopaedic clinical research, the application of machine learning methodology to cohort data from the Multicenter ACL Revision Study (MARS) presents a valuable opportunity to translate data into patient-specific insights. Purpose: To apply novel machine learning methodology to MARS cohort data to determine a predictive model of revision anterior cruciate ligament reconstruction (rACLR) graft failure and features most predictive of failure. Study Design: Cohort study; Level of evidence, 3. Methods: The authors prospectively recruited patients undergoing rACLR from the MARS cohort and obtained preoperative radiographs, surgeon-reported intraoperative findings, and 2- and 6-year follow-up data on patient-reported outcomes, additional surgeries, and graft failure. Machine learning models including logistic regression (LR), XGBoost, gradient boosting (GB), random forest (RF), and a validated ensemble algorithm (AutoPrognosis) were built to predict graft failure by 6 years postoperatively. Validated performance metrics and feature importance measures were used to evaluate model performance. Results: The cohort included 960 patients who completed 6-year follow-up, with 5.7% (n = 55) experiencing graft failure. AutoPrognosis demonstrated the highest discriminative power (model area under the receiver operating characteristic curve: AutoPrognosis, 0.703; RF, 0.618; GB, 0.660; XGBoost, 0.680; LR, 0.592), with well-calibrated scores (model Brier score: AutoPrognosis, 0.053; RF, 0.054; GB, 0.057; XGBoost, 0.058; LR, 0.111). The most important features for AutoPrognosis model performance were prior compromised femoral and tibial tunnels (placement and size) and allograft graft type used in current rACLR. Conclusion: The present study demonstrated the ability of the novel AutoPrognosis machine learning model to best predict the risk of graft failure in patients undergoing rACLR at 6 years postoperatively with moderate predictive ability. Femoral and tibial tunnel size and position in prior ACLR and allograft use in current rACLR were all risk factors for rACLR failure in the context of the AutoPrognosis model. This study describes a unique model that can be externally validated with larger data sets and contribute toward the creation of a robust rACLR bedside risk calculator in future studies. Registration: NCT00625885 (ClinicalTrials.gov identifier).
Surgical Predictors of Clinical Outcome 6 Years After Revision ACL Reconstruction
Background: Revision anterior cruciate ligament (ACL) reconstruction has been documented to have inferior outcomes compared with primary ACL reconstruction. The reasons why remain unknown. Purpose: To determine whether surgical factors performed at the time of revision ACL reconstruction can influence a patient’s outcome at 6-year follow-up. Study Design: Cohort study; Level of evidence, 2. Methods: Patients who underwent revision ACL reconstruction were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline patient characteristics, surgical technique and pathology, and a series of validated patient-reported outcome instruments: Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) subjective form, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx activity rating score. Patients were followed up for 6 years and asked to complete the identical set of outcome instruments. Regression analysis was used to control for baseline patient characteristics and surgical variables to assess the surgical risk factors for clinical outcomes 6 years after surgery. Results: A total of 1234 patients were enrolled (716 men, 58%; median age, 26 years), and 6-year follow-up was obtained on 79% of patients (980/1234). Using an interference screw for femoral fixation compared with a cross-pin resulted in significantly better outcomes in 6-year IKDC scores (odds ratio [OR], 2.2; 95% CI, 1.2-3.9; P = .008) and KOOS sports/recreation and quality of life subscale scores (OR range, 2.2-2.7; 95% CI, 1.2-4.8; P < .01). Use of an interference screw compared with a cross-pin resulted in a 2.6 times less likely chance of having a subsequent surgery within 6 years. Use of an interference screw for tibial fixation compared with any combination of tibial fixation techniques resulted in significantly improved scores for IKDC (OR, 1.96; 95% CI, 1.3-2.9; P = .001); KOOS pain, activities of daily living, and sports/recreation subscales (OR range, 1.5-1.6; 95% CI, 1.0-2.4; P < .05); and WOMAC pain and activities of daily living subscales (OR range, 1.5-1.8; 95% CI, 1.0-2.7; P < .05). Use of a transtibial surgical approach compared with an anteromedial portal approach resulted in significantly improved KOOS pain and quality of life subscale scores at 6 years (OR, 1.5; 95% CI, 1.02-2.2; P≤ .04). Conclusion: There are surgical variables at the time of ACL revision that can modify clinical outcomes at 6 years. Opting for a transtibial surgical approach and choosing an interference screw for femoral and tibial fixation improved patients’ odds of having a significantly better 6-year clinical outcome in this cohort.
Interval Throwing Programs for Baseball Players: Methodological Assessment of the Quality and Construct of Publicly Available Programs
Context: The quality and interprogram variability of publicly available throwing programs have not been assessed. Objective: To (1) identify publicly available interval throwing programs, (2) describe their components and structure, and (3) evaluate their quality, variability, and completeness. Data Sources: Google, Bing, Yahoo; keyword: “interval throwing program.” Study Selection: Baseball-specific publicly available programs. Study Design: Systematic review. Level of Evidence: Level 4. Data Extraction: Independent evaluation by 2 authors using a novel 21-item Quality Assessment Rubric (QAR). Results: Of the 99 included programs, 54% were designed for return from injury/surgery; 42% explicitly stated no expected timeline for completion, and approximately 40% did not provide criteria to initiate the program. Program construction was highly variable. There were broad-ranging shortest (mean: 40±8 ft, range: 20-45 ft) and longest (mean: 150±33 ft, range: 90-250 ft) long toss distances, and variable maximum numbers of mound pitches thrown before returning to game play (range: 40-120, mean: 85). Only 63% of programs provided guidelines for handling setbacks, and standardized warm-ups, arm care, and concomitant training were absent in 32%, 63%, and 47% of programs, respectively. Mean QAR completion rate and QAR item response rate were low (62 ± 4% [range, 24-91%], 62 ± 24% [range, 7-99%], respectively). Finally, only 20 (20%) programs provided at least 1 peer-reviewed reference, most of which were published >10 years ago. Conclusion: Publicly available interval throwing programs are readily available but demonstrate significant interprogram heterogeneity across multiple areas including target audience, program construction, progression, and execution. The quality and consistency of publicly available interval throwing programs is poor at this time, which may limit their utility and effectiveness for baseball players attempting to return to competition. This work identifies a multitude of deficiencies in currently available throwing programs that should be targets of future improvement efforts.
Characteristics Associated With Noncompliance of Current Pitch Smart Guidelines in High School Baseball Pitchers Throughout the United States
Background: Although pitch count and rest guidelines have been promoted for youth and adolescent baseball players for nearly 2 decades, compliance with guidelines remains poorly understood. Purpose/Hypothesis: The purpose of this study was to determine the frequency of compliance with Major League Baseball (MLB) Pitch Smart guidelines as well as the association between compliance and range of motion (ROM), strength, velocity, injury, and pitcher utilization. It was hypothesized that pitchers in violation of current recommendations would have increased strength, velocity, and injury. Study Design: Case-control study; Level of evidence, 3. Methods: This was a prospective, multicenter study of 115 high school pitchers throughout the United States. Pitchers were surveyed about their compliance with current off-season, rest-related guidelines, and history of injury. During the preseason, pitchers underwent standardized physical examinations, and pitch velocity was measured. Pitch counts were collected during the baseball season that followed. Dynamometer strength testing of shoulder forward flexion, and external rotation as well as grip strength was recorded. We compared pitchers who were compliant with recommendations with those who were noncompliant using Student t and Mann-Whitney U tests. Results: Based on preseason data, 84% of pitchers had violated current Pitch Smart guidelines. During the season, 14% had at least 1 violation of the Pitch Smart guidelines. Across both the preseason survey and in-season pitch counts, 89% of players had at least 1 violation of the Pitch Smart guidelines. While there were no significant differences in ROM or strength, the noncompliant group had higher maximum pitch velocity than the compliant group (74 ± 8 vs 69 ± 5 mph [119 ± 13 vs 111 ± 8 kph], respectively; P = .009). Players’ self-reported velocity differed significantly from the direct measurement, for both peak velocity (80 ± 6 vs 73 ± 8 mph [129 ± 9 vs 117 ± 13 kph], respectively; P < .001) and mean velocity (73 ± 8 vs 53 ± 27 mph [117 ± 13 vs 85 ± 43 kph], respectively; P < .001). Conclusion: Most high school pitchers were not fully compliant with current Pitch Smart guidelines, and they tended to overestimate their peak velocity by 7 mph (11 kph). Pitchers who threw with greater velocity were at higher risk for violating Pitch Smart recommendations.
Poster 206: What are the Indications for Medial Ulnar Collateral Ligament Surgery in Baseball Players? An MRI Case-based Study
Objectives: Ulnar Collateral Ligament (UCL) tears are common in baseball players. When non-operative management fails; reconstruction or repair may be necessary to restore physical function. There is no clear consensus regarding the indications for surgery based on magnetic resonance imaging (MRI) tear characteristics, or the indications for selecting repair over reconstruction. The purpose of this study was to define the indications for UCL surgery based on MRI and to elucidate indications for UCL repair vs reconstruction. Methods: Twenty-six orthopaedic surgeons who treat baseball players were surveyed. Forty-five MRIs were reviewed: 15 without UCL tears, 15 with intra-operatively confirmed partial-thickness tears, and 15 with full-thickness tears. Factors investigated included ligament characteristics (peri-ligamentous or osseous edema, ligament hypertrophy, calcification, partial or full-thickness tearing) and location (proximal, mid-substance, or distal). Surgeons were given a clinical scenario and asked whether 1) surgery was indicated and 2) whether repair or reconstruction was recommended. Odds ratios (OR) and 95% confidence intervals (95%CI) helped identify significant predictors for both queries. Results: The odds of recommending surgical treatment compared to non-operative treatment were 2.4x more likely for a proximal partial-thickness tear, 3.2x for distal partial-thickness tear, 5.1x for distal full- thickness tear, and 7.0x for proximal full-thickness tear (p<0.001). Significant indications for repair included distal partial (OR=1.6, 95%CI 1.0, 2.1, p<0.001) and full-thickness tears (OR=1.7, 95%CI 1.1, 2.3, p<0.001). Repair was 3x less likely recommended for mid-substance full-thickness tears (OR=3.0, 95%CI - 5.0, -1.0, p=0.004). Ultrasound stress testing was requested in 78% of partial tears. Conclusions: Among surgeons surveyed, the highest odds for recommending operative treatment were proximal full-thickness tears, then distal full-thickness, distal partial-thickness, and proximal partial- thickness tears. Repair was most appropriate for partial and full-thickness distal tears, but relatively contraindicated for complete mid-substance UCL tears. Ultrasound stress testing was frequently requested for partial tears. Given the lack of consensus among surgeons, future prospective registries are necessary to determine whether these factors associate with clinical outcomes. [Table: see text]
Poster 167: Increased Throwing Velocity is Correlated with a Higher Likelihood of Violating Current Pitch Count Recommendations in High School Baseball Pitchers.
Objectives: While pitch count and rest guidelines have been promoted for youth and adolescent baseball players for nearly two decades, compliance with guidelines remains poorly understood. The purpose of this study was to determine the frequency of compliance with Pitch Smart guidelines, as well as the association between compliance and range of motion, strength, velocity, injury, and pitcher utilization. Methods: This study was a prospective, multi-center study of high school pitchers, encompassing each region of the United States. Pre-season pitchers were surveyed about their compliance with current off- season rest-related guidelines and history of injury. Pre-season, pitchers underwent standardized physical examinations and pitch velocity was measured. During the high school season that followed, both pitch counts and injury incidence were collected. Results: One hundred and fifteen pitchers participated. Based upon pre-season data, 84% of pitchers had previously violated current pitch recommendation guidelines. During the season, 14% had at least one instance of a violation of the current pitch counts guidelines. Across both the pre-season survey and in-season pitch counts, 89% of players had at least one violation of the current Pitch Smart guidelines. While there were no significant differences in range of motion or strength, those pitchers who were non-compliant with guidelines in the pre-season had higher max pitch velocity (mean±standard deviation 74±8 miles per hour vs. 69±5 miles per hour, p=0.009). Pitchers self-reported their peak velocity at 7 MPH greater than the actual measured velocity. Only a single injury occurred during the season, precluding a comparison between groups. There were no significant differences in the incidence of a history of injury between those pitchers who were noncompliant with between-season rest guidelines (p=0.285). Conclusions: Most high school pitchers are non-compliant with current Pitch Smart guidelines, and they tend to overestimate their peak velocity by 7 MPH. Pitchers with greater velocity were at the highest risk for violating current pitch count recommendations. Since both increased throwing volume and pitch velocity are known risk factors for injury, these athletes may be at particular risk for subsequent injury. research is necessary to understand whether taking three consecutive month rest between seasons prevents pitching-related injury.
Meniscal and Articular Cartilage Predictors of Outcome After Revision ACL Reconstruction: A 6-Year Follow-up Cohort Study
Background: Meniscal and chondral damage is common in the patient undergoing revision anterior cruciate ligament (ACL) reconstruction. Purpose: To determine if meniscal and/or articular cartilage pathology at the time of revision ACL surgery significantly influences a patient’s outcome at 6-year follow-up. Study Design: Cohort study; Level of evidence, 3. Methods: Patients undergoing revision ACL reconstruction were prospectively enrolled between 2006 and 2011. Data collection included baseline demographics, surgical technique, pathology, treatment, and scores from 4 validated patient-reported outcome instruments: International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx Activity Rating Scale. Patients were followed up at 6 years and asked to complete the identical set of outcome instruments. Regression analysis assessed the meniscal and articular cartilage pathology risk factors for clinical outcomes 6 years after revision ACL reconstruction. Results: An overall 1234 patients were enrolled (716 males, 58%; median age, 26 years). Surgeons reported the pathology at the time of revision surgery in the medial meniscus (45%), lateral meniscus (36%), medial femoral condyle (43%), lateral femoral condyle (29%), medial tibial plateau (11%), lateral tibial plateau (17%), patella (30%), and trochlea (21%). Six-year follow-up was obtained on 79% of the sample (980/1234). Meniscal pathology and articular cartilage pathology (medial femoral condyle, lateral femoral condyle, lateral tibial plateau, trochlea, and patella) were significant drivers of poorer patient-reported outcomes at 6 years (IKDC, KOOS, WOMAC, and Marx). The most consistent factors driving outcomes were having a medial meniscal excision (either before or at the time of revision surgery) and patellofemoral articular cartilage pathology. Six-year Marx activity levels were negatively affected by having either a repair/excision of the medial meniscus (odds ratio range, 1.45-1.72; P≤ .04) or grade 3-4 patellar chondrosis (odds ratio, 1.72; P = .04). Meniscal pathology occurring before the index revision surgery negatively affected scores on all KOOS subscales except for sports/recreation ( P < .05). Articular cartilage pathology significantly impaired all KOOS subscale scores ( P < .05). Lower baseline outcome scores, higher body mass index, being a smoker, and incurring subsequent surgery all significantly increased the odds of reporting poorer clinical outcomes at 6 years. Conclusion: Meniscal and chondral pathology at the time of revision ACL reconstruction has continued significant detrimental effects on patient-reported outcomes at 6 years after revision surgery.
Isolated, Full-Thickness Proximal Rectus Femoris Injury in Competitive Athletes: A Systematic Review of Injury Characteristics and Return to Play
Background: Characteristics regarding mechanism of injury, management, and return-to-play (RTP) rate and timing are important when treating and counseling athletes with rectus femoris tears. Purpose: To systematically review the literature to better understand the prevalence, sporting activity, injury mechanisms, and treatment of patients with rectus femoris injury and to provide prognostic information regarding the rate and timing of RTP. Study Design: Systematic review; Level of evidence, 4. Methods: Following the 2020 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we queried PubMed/MEDLINE, Cochrane, OVID, EMBASE, and Google Scholar in March 2022 for studies reporting on athletes sustaining isolated, full-thickness tearing, or bony avulsion injuries to the proximal rectus femoris during sporting activity. Excluded were studies without evidence of full-thickness tearing or avulsion, with athletes sustaining concomitant injuries, or with injuries occurring from nonsporting activities. The percentage of athletes sustaining injuries was calculated based on sport, injury mechanism, and management (nonoperative versus operative). Results: Of 132 studies initially identified, 18 were included, comprising 132 athletes (mean age, 24.0 ± 5.4 years; range, 12-43 years). The most common sporting activities were soccer (70.5%) and rugby (15.2%). The most reported mechanisms of injury were kicking (47.6%) and excessive knee flexion/forced hip extension (42.9%). Avulsion injuries were reported in 86% (n = 114) of athletes. Nonoperative management was reported in 19.7% of athletes, with operative management performed in 80.3%. The mean follow-up time was 21.4 ± 11.4 months (range, 1.5-48 months). The RTP rate was 93.3% (n = 14) in nonoperatively treated and 100% (n = 106) in operatively treated athletes, and the mean RTP time was 11.7 weeks (range, 5.5-15.2 weeks) in nonoperatively treated and 22.1 weeks (range, 14.0-37.6 weeks) in operatively treated athletes. Complications were reported in 7.7% (2/26) of nonoperatively treated and 18% (n = 19/106) of operatively treated athletes. Conclusion: Full-thickness proximal rectus femoris injuries occurred most frequently in athletes participating in soccer and rugby secondary to explosive, eccentric contractions involved in kicking and sprinting. Operative management was performed in the majority of cases. Athletes who underwent operative repair had a 100% RTP rate versus 93.3% in athletes treated nonoperatively.