Coracoacromial arch decompression in rotator cuff surgery

Massive rotator cuff tears repaired on top of humeral head by McLaughlin's procedure

The clinical and radiographic outcomes of McLaughlin's procedure for massive rotator cuff tears were investigated in 25 shoulders, in which the cuff tears were so severe that the tendons were sutured on the top of the humeral head. The mean age at surgery was 62.2 years (range, 39-74 years). The mean follow-up period was 50 months (range, 24-80 months). The University of California, Los Angeles score significantly improved from 10.9 to 31.8 points postoperatively; the postoperative result was classified as excellent in 11 shoulders, good in 11, and poor in 3. Osteoarthritis progressed postoperatively in 7 shoulders (28%), and upper migration of the humeral head progressed in 6 (24%), although both progression rates were no higher than those for other common procedures. When torn tendons reach over the top of the humeral head with the arm at the side in patients with massive tears that are not reparable to the greater tuberosity, satisfactory clinical outcomes can be expected.

A study for evaluating the effect of the deltoid-flap repair in massive rotator cuff defects

The repair of massive cuff defects by direct suture often is impossible. In these cases, a repair by musculo-tendineous flaps (latissimus-dorsi, pectoralis or deltoideus) is required. It was the goal of this study to evaluate the result of delta-flap repair in case of massive cuff defects with a diameter of 5 cm or more. Between 1998 and 2000 for all patients who were suffering from a massive rotator cuff tear more than 5 cm a deltoid transfer was performed. A total of 20 patients (14 male, 6 female; age: 60.9+/-8.7 years) were available for a follow-up after 47.2+/-8.0 (range, 36 to 60) month. The operation included an arthroscopic evaluation, acromioplasty with resection of the lateral clavicular end, and biceps tenodesis. The cuff defect was repaired by transfer a muscular flap from the anterior part of the deltoid (about 2 x 6 cm) into the defect. The patients subjectively rated their result-10 excellent, 9 good, and 1 poor. Preoperatively, the Constant amounted 26.3+/-5.1 points. At follow-up, the score significantly increased to 74.5+/-8.5 points. The acromiohumeral distance increased from 4.9+/-1.1 to 9.2+/-1.7 mm. In MRI examination of 11 patients all had an intact flap. Two complications (a wound hematoma and a deep infection) did not influence the result. The repair of massive rotator cuff tears by a deltoid transfer produces acceptable clinical and radiological results.

Coracoid tip position on frontal radiographs of the shoulder: a predictor of common shoulder pathologies?

The coracoacromial arch is a static anterior-superior stabilizer of the humeral head. Thus coracoacromial arch inclination, which varies depending on coracoid tip position, may be related to shoulder pathologies. Therefore, we retrospectively analysed coracoid tip positions in the true anterior posterior view of different shoulder pathologies: reference shoulders (n=27), shoulders with rotator cuff tear (supraspinatus tear n=29; subscapularis tear n=21) and shoulders with anterior glenohumeral instability (traumatic n=17; atraumatic n=14). In supraspinatus tear shoulders, the coracoid tip projected onto inferior glenoid half in 86% of cases (type I coracoid), extending more inferiorly compared with reference group (p=0.0002) or subscapularis tear shoulders (p<0.0001). In contrast, 78% of cases with subscapularis tear show the coracoid tip projected onto the superior glenoid half (type II coracoid). Atraumatic glenohumeral instabilities had a more superior coracoid tip position than traumatic instabilities (p=0.04), but no differences were observed on basis of coracoid type or in comparison with normal controls. We conclude that coracoid tip position is highly variable. Since type I coracoids are predominant in shoulders with supraspinatus tears and type II coracoids in shoulders with subscapularis tears, coracoid tip position may thus provide a simple diagnostic complement for a probable site of rotator cuff tears.

Stress distribution patterns at the coracoacromial arch in rotator cuff tear measured by computed tomography osteoabsorptiometry

When a rotator cuff tear occurs, forces compressing the humeral head toward the glenoid are disturbed, and the kinematics of the glenohumeral joint change. Therefore, stress distributions at the coracoacromial arch in cuff tear shoulders should differ from those in normal shoulders. To investigate this hypothesis, we studied stress distribution patterns at the coracoacromial arch in normal and cuff tear shoulders using a computed tomography (CT) osteoabsorptiometry method, in which bone density correlates directly with long-term physiologic loading. Eight normal subjects and 11 patients with cuff tear were examined. The stress distributions at the undersurface of the acromion and the posterolateral surface of the coracoid process differed markedly between normal and cuff tear shoulders. In cuff tear shoulders, a high-density area was located at the anterior or the anterolateral part of the undersurface of the acromion, while it was located at the posterior part in all but one normal shoulder. Additionally, a high-density area was located at the superior or the lateral part of the coracoid process in most of the cuff tear shoulders; on the other hand, it was located at the base in all but one normal shoulder. We believe that the differences in stress distribution patterns are due to impingement at the coracoacromial arch in cuff tear shoulders. CT osteoabsorptiometry can provide useful information in performing coracoacromial arch decompression for cuff tear shoulders.