Factors influencing outcomes of nonsurgical treatment for baseball players with SLAP lesion

BACKGROUND/OBJECTIVE: Superior labrum anterior posterior (SLAP) lesion of the shoulder joint occurs in throwing athletes as a results of overuse, such as from repetitive baseball pitching. Nonsurgical treatments are usually the first-line therapy for symptomatic SLAP lesion. However, some patients cannot obtain satisfactory improvement of their symptoms, leading to dysfunction of the shoulder and diminished pitching performance. The purpose of this study was to analyze factors that influence outcomes of nonsurgical treatments for SLAP lesion. METHODS: Forty-five baseball players with SLAP lesion, whose mean age was 21.6 (range, 16–36) years and who underwent nonsurgical treatments, were the subjects of this study. SLAP lesion was diagnosed by shoulder arthrography and magnetic resonance imaging (MRI). Exclusion criteria included definite associated trauma such as dislocation, fracture or injuries related to sports activities. Playing positions included pitcher (21 patients), catcher (3 patients), infielder (13 patients) and outfielder (8 patients). Mean symptomatic duration from the onset of shoulder pain to the beginning of nonsurgical treatments was 8.5 (range, 1–72) months. Nonsurgical treatments included physical therapy, such as range of motion, stretching, and rotator cuff exercises, as well as prescription of nonsteroidal anti-inflammatory drugs if necessary. To identify factors that influenced outcomes of nonsurgical treatments for SLAP lesion, various factors of 13 nonresponsive patients were compared with those of 32 patients who responded to nonsurgical treatment. The factors were as follows: patient background, such as age or playing position; range of shoulder motion; shoulder joint laxity; and findings of radiographs and MRI. All data were statistically assessed using logistic analysis and Spearman's correlation coefficient. The significance level was set at P < 0.05, and odds ratios were determined. RESULTS: Factors identified as having significant difference between the 2 groups were age, duration of baseball experience, symptomatic period, playing position, range of internal and external rotation in the first medical examination, range of total rotation of 90° abduction 2 months after nonsurgical treatments, and presence of Bennett spur and partial-thickness tears of the articular-side rotator cuff. Factors with high odds ratios were symptomatic period, range of total rotation of 90° abduction 2 months after the treatment, age, and duration of baseball experience. CONCLUSION: Symptomatic period, duration of baseball experience, age, and findings of radiographs and MRI are inevitable factors that cannot be improved by nonsurgical treatment. On the other hand, restriction of shoulder motion due to posterior muscular tightness is a factor that can be improved by nonsurgical treatment. Early improvement of shoulder motion is important to obtain satisfactory outcomes of nonsurgical treatments for SLAP lesion.