Abstract & Commentary
Synopsis: A retrospective review was performed to evaluate the preliminary results of 25 consecutive arthroscopic subscapularis tendon repairs. This study concludes that: 1) arthroscopic repair of torn subscapularis tendons can be consistently performed with good-to-excellent results; 2) the Napoleon test is useful in detecting the presence and size of subscapularis tendon tears; and 3) arthroscopic repair of massive rotator cuff tears can produce durable reversal of proximal humeral migration and restoration of overhead function.
Source: Burkhart SS, Tehrany AM. Arthroscopic subscapularis tendon repair: Technique and preliminary results. Arthroscopy. 2002;18:454-463.
This retrospective case series reviewed Burkhart’s early experience performing 32 arthroscopic subscapularis tendon repairs. Twenty-five shoulders with more than 3 months follow-up were reviewed with an average duration of just 10.7 months. Isolated subscapularis tears occurred in 8 shoulders, while massive rotator cuff tears, defined by a complete subscapularis tear combined with supraspinatous and infraspinatous tears, were identified in 6 shoulders.
The UCLA score improved from an average preoperative value of 10.7 to a postoperative average value of 30.5 (P < 0.0001). In the 6 patients with massive rotator cuff repairs, the UCLA score improved from 9.5 to 28.3 (P < 0.001). For the 8 patients with isolated subscapularis tears, the UCLA score improved from 10 to 32.8 (P < 0.002). Overall, forward flexion increased from an average of 96.3° to 146.1° (P < 0.01). There were 2 reruptures and no other clinically significant complications in this preliminary study.
The Napoleon and lift-off tests were used to evaluate the condition of the subscapularis tendon prior to surgery. To perform the Napoleon test, patients were instructed to place their hand on their stomach and push posteriorly. The Napoleon test was considered normal if the patient could push the hand against the stomach and maintain a straight wrist; positive if the wrist flexed 90°; and intermediate if the wrist flexed 30° to 60°. The lift-off test was performed by placing the dorsum of the hand against the lower back and instructing the patient to actively "lift-off" the hand from the back. All patients tolerated the Napolean test during clinical examination. In contrast, the lift-off test could not be performed due to pain or restricted motion in 19 of 25 patients. The Napoleon test was thought best to correlate with the condition of the subscapularis. All patients with a negative or normal Napoleon test were found to have tears confined to the upper half of the subscapularis tendon. Eight of 9 patients with a positive Napoleon test had complete tears of the subscapularis. Incomplete tears involving more than 50% of the tendon tended to have intermediate Napoleon tests.
Proximal humeral migration, defined as an acromiohumeral interval of less than 5 mm and an inferior humeral head-inferior glenoid articular margin of greater than 5 mm, occurred in 10 patients (40%). Eight out of 10 patients had reversal of proximal humeral migration on postoperative radiographs. In 2 patients with recurrent proximal humeral migration, forward flexion improved to < 110° and the UCLA scores were poor and fair. Recurrent proximal humeral migration was felt to correlate with a poor outcome.
Comment by Robert C. Schenck, Jr., MD, & John C. Franco, MD
Isolated subscapularis tears and massive rotator cuff tears involving the subscapularis tendon can be debilitating problems and challenging to repair. Patients with isolated subscapularis tears can experience anterior shoulder instability and profound loss of shoulder internal rotation strength. Massive rotator cuff tear involving the subscapularis produces global shoulder instability and painful loss of shoulder function. Virtually all researchers recommend operative treatment of a torn subscapularis tendon.1-4
The theoretical advantages of arthroscopic subscapularis repair include a minimally invasive approach, limited risk to extra-articular neurovascular structures, and little risk of additional functional loss to the deltoid when an irreparable rotator cuff tear is encountered. Burkhart and Tehrany report the first series of arthroscopic rotator cuff repair with remarkably good to excellent results in 92% of patients. The outcome of arthroscopic subscapularis repair in cases of isolated tendon rupture was most successful. The final UCLA shoulder score (32.8/35) compares favorably with the final Constant score (82/100) reported by Gerber2 following open repair of islolated subscapularis tear.
Repair of massive rotator cuff tears, especially anterior-superior tears involving subscapularis, can be extremely difficult, results are often poor, and rerupture is not uncommon. Warner reported an average Constant score of 69 and excellent or good results in only 8 of 19 open anterior-superior rotator cuff repairs.3 Gerber reported on 29 open massive rotator cuff repairs (13/29 involving supscapularis) and demonstrated an average Constant score of 85 and improvement in pain free forward flexion to 142°.4 These experiences are important benchmarks to compare any long-term follow-up of a new arthroscopic procedure. We agree that the Napoleon test is useful in diagnosing supscapularis tears, especially when shoulder internal rotation is limited and/or painful. The correlation between the Napoleon test result and the intraoperative condition of the subscapularis is an interesting finding that may prove useful in preoperative planning and patient counseling. In our experience, the use of clinical findings to verify the presence of a subscapularis tear are experience dependent with occasional presence of false negatives, and frequently require both clinical examination and MRI evaluation.
There are 2 main concerns with regards to this study. The first is the relative short follow-up. Compared to reports of open subscapularis repair with up to 3-year follow-up, final follow-up in this series averaged 10 months and deterioration in objective and subjective results, as well as a higher rate of rerupture, may occur with longer follow-up. That being said, the early results of arthroscopic subscapularis repair are very encouraging. The second concern is that of technical difficulty. The practicing clinician is best advised to repair the subscapularis with a familiar and reproducible technique, in his or her hands. Certainly, the presence of a displaced biceps tendon with a complete subscapularis tear adds to the technical challenge of such a repair, be it open or arthroscopic. Further experience in addition to longer follow-up of this group of patients is needed before arthroscopic subscapularis tendon repair is considered a routine technical exercise.
Dr. Schenck, Deputy Chairman, Department of Orthopaedics, University of Texas Health Science Center, San Antonio, TX, is Associate Editor of Sports Medicine Reports. Dr. Franco is an Orthopaedic Resident, Department of Orthopaedics and Rehabilitation, University of New Mexico School of Medicine, Albuquerque.
References
1. Postacchini F, Gumina S. Results of surgery after failed attempt at repair of irreparable rotator cuff tear. Clinical Orthopaedics & Related Research. 2002; 397:332-341.
2. Gerber C, Hersche O, Farron A. Isolated rupture of subscapularis tendon. Results of operative repair. J Bone Joint Surg. 1996;78-A:1015-1023.
3. Warner J, et al. Diagnosis and treatment of anterosuperior rotator cuff tears. J Shoulder Elbow Surg. 2001; 10:37-46.
4. Gerber C, Fuchs B, Hodler J. The results of repair of massive tears of the rotator cuff. J Bone Joint Surg. 2000;82-A:505-515.
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