Muscle Imbalance in Volleyball Players Initiates Scoliosis in Immature Spines: A Screening Analysis

STUDY DESIGN: Retrospective comparative study using radiographs and clinical findings. PURPOSE: To test the hypothesis that asymmetric loading of immature spines in young athletes initiates scoliosis. OVERVIEW OF LITERATURE: Scoliosis in athletes has been reported in the literature, but its causative factors have not been investigated. METHODS: We compared the incidence, type and magnitude of scoliotic curves in volleyball players with those in the non-player population. One hundred sixteen adolescent volleyball players were grouped for selective screening. Data regarding their playing duration, handedness, age, height, and menarchal status (in girls) were recorded, along with clinical examination and radiological investigation when necessary. We analyzed data from 46,428 non-player school children, and their data were compared to athletes to determine differences. RESULTS: Volleyball players had a statistically significant increase in the incidence of scoliotic spinal curves. Playing hand dominance was related to the curve direction. Cobb angle had no significant correlation with the duration of playing. CONCLUSIONS: There is a five-fold increase in the incidence of mild scoliosis in volleyball players. A high percentage (41%) of asymmetry was present on the Adams forward bending test, as compared to controls. The curves were either thoracic or thoracolumbar.

Comparison of Apical Axial Derotation between Adolescent Idiopathic and Neuromuscular Scoliosis with Pedicle Screw Instrumentation

STUDY DESIGN: A retrospective study. PURPOSE: To compare outcomes of apical derotation with pedicle screws in idiopathic and neuromuscular scoliosis (NMS). OVERVIEW OF LITERATURE: No information about apical derotation in NMS with pedicle screws is available. METHODS: We performed deformity correcting surgery using pedicle screw constructs on 12 adolescent idiopathic scoliosis (AIS) patients (mean age 14.1 years) and 16 NMS patients (mean age 16.5 years). Preoperative, postoperative, and final follow-up radiographs were analyzed for Cobb's angle and pelvic obliquity, while apical rotation was measured on CT scans using the Aaro-Dahlborn method. RESULTS: For AIS, the mean preoperative Cobb's angle, pelvic obliquity, and apical rotation values were 57.3degrees, 2.8degrees, and 20.4degrees, respectively, and postoperatively they were 16.8degrees, 1.1degrees and 14.7degrees, respectively, showing significant correction. For NMS, the mean preoperative Cobb's angle, pelvic obliquity, and apical rotation values were 75.6degrees, 13.7degrees, and 42.9degrees, respectively, and postoperatively they were 27.1degrees, 5.8degrees, and 34.1degrees, respectively, also showing significant correction. There were no significant differences between AIS and NMS patients Cobb's angle p=0.306, pelvic obliquity p=0.887 and apical derotation p=0.113degrees. There were no differences in curve severity in the three groups (AIS, NMS >80degreesand NMS 80 NMS group (p=0.04). CONCLUSIONS: Apical axial derotation can be achieved with posterior only pedicle screw fixation in NMS without anterior release, with comparable results in idiopathic scoliosis.