Abstract
In order to understand the natural course of the pathological conditions of baseball elbow, a long-term follow-up study was made of 32 cases, aged 22.4 years on an average, who had not been surgically treated. At least 4 years had passed since their first consultation at our department; their mean age then had been 15.3. Plain roentgenography and tomography were performed for all cases.
Baseball elbow was classified into 4 types according to the site involved; the radiohumeral joint type (RH type) corresponding to osteochondritis dissecans, the ulnar collateral ligament impairment type (UCL type), the osteoarthritic type (OA type) showing osteoarthritic changes at the first consultation, and the miscellaneous type including the olecranon type. There were 8 cases of the RH type, 8 of the UCL type, 6 of the OA type and 10 of the miscellaneous type. All 32 cases were also divided into a non-stress group (n=15) and a stress group (n=17) based on the magnitude of stress on the elbow joint after the first consultation.
Pathological conditions were evaluated clinically according to the site involved, the amount of stress, and the location of spur formation. RH type and OA type patients often felt pain upon movement, and the excursion of the impaired elbow had decreased slightly compared to that of the healthy elbow. Patients with the UCL type and the miscellaneous type showed satisfactory outcomes compared to those with the other two types. In the stress group, 12 of the 17 patients (70%) showed osteoarthritic changes which were not seen in the 3 patients (18%) with UCL type and the 2 patients (12%) with miscellaneous type. Patients with RH or OA type invariably developed elbow osteoarthritis when they stressed their elbow joints by playing baseball. RH-type patients also showed marked deformity at the humeroradial joint as well as spur formation at the ulnar margin of the humeroulnar joint. In UCL-type patients, only a few spurs were formed, but only at the medial epicondyle; it was notable that no spurs were detected at the humeroradial joint. We concluded that RH-type baseball elbow is difficult to treat conservatively.
