抄録
[Purpose] Does repetitive throwing influence the glenoid version and torsion of the humeral head ?The aim of this study is to estimate the influence for the version and torsion in athletes who participate in beseball from a certain growth period.
[Material and Methods] Computerized tomographic scans were made for 64 shoulders of thirty-two baseball players with an average age 24.0 years. And 20 shoulders of ten non-baseball players, with an average age 29.0 years as the control group. On each scan, we drew four lines: a perpendicular line to a line connecting the peripheral margins of the articular surface of the humelal head (line A): a line connecting the central point of the humeral epicondyle (line B): a line drawn from the mid-point of the glenoid fossa to the medial end of the scapula (line C): and a perpendicular line to a line connecting the anterior and posterior margins of the glenoid fossa (line D). The angles between line A and B, and between line C and D were taken as torsion of the humeral head and glenoid version respectively.
[Results] The average angle of the glenoid version was -4.26° on the throwing side and -1.18° on the non-throwing side. In the control group, the average angle of the glenoid version was -0.27° on the dominant and -1.72 ° on the non-dominant side. The average angle of the retroversion was 36.02° on the thowing and 29.56° on the non-throwing side. In the control group, the average angle of the retroversion was 28.52° on the dominant and 29.66° on the non-dominant side. There was a statistically significant difference between the throwing and non-throwing sides.
[Conclusion] These results suggested that excessive and repetitive stress to the humerus during a growth period influenced the version and trorsion
