Radiologic and Histologic Evaluation of Proximal Bicep Pathology in Patients With Chronic Biceps Tendinopathy Undergoing Open Subpectoral Biceps Tenodesis.

PURPOSE: To correlate preoperative magnetic resonance imaging (MRI) and intraoperative anatomic findings within the proximal long head biceps tendon to histologic evaluation of 3 separate zones of the tendon in patients with chronic biceps tendinopathy.

METHODS: Sixteen patients with chronic biceps tendinopathy were treated with open subpectoral biceps tenodesis. Preoperative MRI tendon grading was as follows: normal tendon, increased signal, tendon splitting, incomplete/complete tear. The removed portion of the biceps tendon was split into 3 segments: zone 1, 0-3.5 cm from the labral insertion; zone 2, 3.5-6.5 cm; and zone 3, 6.5-9 cm, and was histologically evaluated using the Bonar score. Tenosynovium adjacent to the tendon was assessed histologically using the Osteoarthritis Research Society International score. CD31, CD3, and CD79a immunohistochemistries were conducted to determine vascularization, T-cell infiltrates, and B-cell infiltrates, respectively. Analysis of variance and Pearson correlations were performed for statistical analysis.

RESULTS: Preoperative MRI showed no significant differences in tendon appearance between zones 1-3. Intraoperative findings included nonspecific degenerative SLAP tears or mild/moderate biceps tenosynovitis in all cases. Significantly (P < .001) higher Bonar scores were noted for tendon in zones 1 (7.9 ± 1.8) and 2 (7.3 ± 1.5) compared with zone 3 (5.0 ± 1.1). Cell morphology scores in zone 1 (1.9 ± 0.4) and zone 2 (1.5 ± 0.6) were significantly higher than that in zone 3 (0.8 ± 0.3) (P < .05). Inflammatory tenosynovium showed weak correlation with tendon changes in zone 1 (r = 0.08), zone 2 (r = 0.03), or zone 3 (r = 0.1).

CONCLUSIONS: In patients with chronic long head biceps tendinopathy who underwent open subpectoral tenodesis, MRI and intraoperative assessment did not show significant structural abnormalities within the tendon despite significant histopathologic changes. Severity of tendon histopathology was more pronounced in the proximal and mid-portions of the tendon.

CLINICAL RELEVANCE: Proximal versus distal biceps tenodesis is a subject of frequent debate. This study contributes to the ongoing evaluation of the characteristics of the proximal biceps in this type of pathologic condition.