Clinical and structural results of partial tears of the supraspinatus tendon treated by endoscopic subacromial decompression without repair

Patients with primary impingement and articular sided partial tears of the supraspinatus tendon are often treated by subacromial decompression without repair, if the extent of the tear is estimated to be below 50% of tendon thickness. It has been questioned whether repair of these cuff lesions is necessary because these tears could progress to full thickness tears with deteriorating clinical results. Our hypothesis was that subacromial decompression without repair of the supraspinatus tendon leads to significant clinical improvement for patients with grades I and II articular sided tears without progression to a full thickness tear on a regular basis. A total of 46 consecutive patients (average age 59.2 years, range 33-76.6 years) were retrospectively reviewed after an average follow-up of 50.3 months (36-86 months). Of these patients 26 (43.5%) had a grade I tear according to Ellman which was not treated and 20 patients suffered from a grade II tear which was treated by intra-articular debridement. Clinical outcome was assessed with the ASES score and ultrasound evaluation was performed on all patients to detect possible progression to a full thickness tear. The average ASES score significantly improved from 37.4 to 86.6 points (p<0.0001). The mean postoperative Constant score was 87.6 points. Only three patients (6.5%) progressed to a full thickness tear detectable by ultrasound examination. Only one of these patients had a poor result with an ASES score of 35 points, the other two were very satisfied with the results and had an ASES score above 90 points. Overall clinical outcome was rated excellent in 35 cases (76.1%), good in 5 (10.9%), average in 2 (4.3%) and poor in 4 (8.7%). Our results indicate that good and excellent results can be achieved mid-term by acromioplasty without repair of the rotator cuff in articular sided partial tears of the supraspinatus tendon grades I and II. Progression to a full thickness tear was rare in our study group (6.5%) and not always associated with a poor outcome. However, with follow-up in excess of 5 years the clinical outcome was significantly worse.