PREDICTING OUTCOMES AFTER SUBACROMIAL DECOMPRESSION USING HISTOLOGICAL ANALYSIS OF THE CORACOACROMIAL LIGAMENT AND THE SUBACROMIAL BURSA

Abstract

The aim of this study was to observe the macroscopic and microscopic appearance of the Coracoacromial ligament and Subacromial bursa during Subacromial decompression and correlate it with the outcome at 3 months. Twenty patients with Subacromial Impingement without Rotator Cuff tear and five patients with large/massive irreparable Rotator Cuff tears who underwent a Subacromial Decompression. Patients with other shoulder pathology were excluded. Patients completed an Oxford Shoulder Score pre-operatively and their injection history was noted. At operation the shape of the acromion was noted. The macroscopic appearance of the CA ligament and the Subacromial bursa was classified as normal, mild/moderate and severe. Biopsies of the Subacromial bursa and CA ligament were taken and were analysed using histological and contempory immunocytochemical techniques. A histological analysis was performed using Mayer’s Haemotoxylin and Eosin, Toluidine Blue and Congo Red. Sections were stained with primary antibodies against PCNA (Proliferating cell nuclear antigen), Mast Cell Tryptase, CD3 (T-cell), CD20 (B cell), CD 34 (QBEnd 10), CD45 (Leucocyte Common Antigen), CD68 and D2–40 (Lymphatic Endothelial Marker). Post operatively the patients completed an Oxford Shoulder Score at 3 months. All the patients demonstrated an improvement in their Oxford Shoulder Score. The histological analysis demonstrated thickening of the synovial membrane and increased vascularity within the bursa and ligament. Increased numbers of inflammatory cells were present within the ligament and bursa of patients with impingement compared with massive rotator cuff tears. There was a relationship between outcome and the appearance of the bursa and ligament.