Innervation pattern at the undersurface of the extensor carpi radialis brevis tendon in recalcitrant tennis elbow.

PURPOSE: We investigated the general, sensory, and sympathetic innervation patterns at the undersurface of the extensor carpi radialis brevis (ECRB) origin in patients with recalcitrant tennis elbow. METHODS: Eight elbows in eight consecutive patients (6 females and 2 males) with tennis elbow who underwent arthroscopic surgery were included in this study. The mean age was 45 years (38-66 years), and the mean duration of symptoms before surgery was 23 months (13-52 months). Operative treatment consisted of an arthroscopic inspection and debridement of the ECRB origin. Control tissues were obtained from biopsy of the ECRB capsule in two patients with osteochondritis dissecance of the capitellum who underwent arthroscopic resection of loose bodies. The tissue specimens were investigated immunohistochemically with antibodies delineating general (PGP9.5), sensory (SP/CGRP), and sympathetic (NPY) nerve patterns. RESULTS: In the non-tendinosis control tissue, SP/CGRP and NPY immunoreactions were heterogeneously distributed in association with blood vessels. Pathologic evaluation of the biopsy tissue showed atypical fibrous granulation containing numerous vessels and nerve structures in all eight patients. Marked reactions to PGP 9.5 took the form of nerve fibers associated with arteries and arterioles in the atypical granulation. Most of the perivascular innervation was found to express NPY. The immunoreactions for SP and CGRP were invariably weak. CONCLUSION: Increased perivascular sympathetic innervation accompanied with loss of sensory innervation at the undersurface of the ECRB tendon may play a role in chronic pain generation in recalcitrant tennis elbow. LEVEL OF EVIDENCE: Diagnostic, Level IV.

Radiocapitellar cartilage injuries associated with tennis elbow syndrome.

PURPOSE: A recent anatomical study has suggested that considerable contact between the undersurface of the extensor carpi radialis brevis (ECRB) and the lateral edge of the capitellum is the cause of tendon injury in lateral epicondylosis. We hypothesized that this contact might concurrently induce cartilage injuries of the capitellum. The purpose of the present study was to determine the prevalence, location, and severity of cartilage lesions of the radiocapitellar joint accompanying lateral epicondylosis and to identify their correlation with ECRB status. METHODS: Arthroscopic assessment of the articular cartilage was performed for 31 elbows in 31 patients with lateral epicondylosis who had surgery. The study group consisted of 18 women and 13 men with a mean age of 50 years (range, 35 to 67 y). The relationship between the presence of the cartilage lesions and patient demographics, preoperative pain visual analog scale score, number of cortisone injections, and surgical findings including ECRB tears were investigated. RESULTS: Cartilage injuries of the capitellum were found in 20 (65%) and cartilage injuries of the radial head were found in 25 (81%) of 31 elbows. Most of the lesions were located on the lateral aspect of the capitellum and radial head. Multivariate logistic regression analysis revealed that the absence of ECRB tears was independently associated with a higher risk of cartilage injuries of the capitellum. CONCLUSIONS: Cartilage injury was frequently found in the lateral edge of the capitellum and radial head. Lesions of the capitellum were related to the absence of ECRB tears. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.