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.