By Mark D. Miller, MD
Although shoulder arthroscopy has become very popular and has been advocated for instability, there is often no substitute for an open procedure. There are several reasons for this, including the ability to address associated capsular laxity and to anatomically correct labral avulsions, the capability to visualize and accurately treat rotator interval lesions, and the capacity to address bony defects of both the glenoid and humerus. Perhaps most importantly, open procedures have a better record of success—that is why it remains the gold standard for the treatment of shoulder instability!
Shoulder dislocations, especially repetitive dislocations, are associated with capsular plastic deformation.1 Capsular laxity is difficult to address arthroscopically, and this may explain higher failure rates in some series. Treatment of associated laxity with thermal devices has been met with mixed results and a variety of complications including tissue necrosis. Arthroscopic plication procedures are in their infancy and are too technically demanding for most surgeons. An open capsulorraphy is a well-established procedure that can reduce capsular volume up to 50%.2
Several researchers have demonstrated difficulty with accurate restoration of the normal glenoid-labrum interface with suture anchors. Medial placement of the labrum results in a condition similar to a chronic ALPSA lesion with healing to the neck of the glenoid. Arthroscopic knot tying is a skill that is not easily mastered, and knot slippage is common. Other technical difficulties, including soft tissue entrapment, suture management, and accurate placement of anchors and sutures, can be avoided with open procedures.
Rotator interval lesions are virtually impossible to visualize arthroscopically. Large openings in this region have been associated with recurrent instability.3 Identification and closure of these lesions (with imbrication) is very easy during open procedures.
Large bony Bankart lesions and Hill-Sachs lesions have been associated with a higher incidence of failure following surgical treatment of shoulder instability. Although a variety of procedures have been described to address these lesions (including osteotomies and bone grafting), none of them are arthroscopic techniques.
A variety of arthroscopic procedures have been described for shoulder instability. The earliest attempts at arthroscopic treatment involved the use of metal staples. Unfortunately, the recurrence rate for these procedures often approached 30%, and pain was present in approximately 50% of the patients.4 Complications including staple breakage, migration, cartilage injury, and infection contributed further to the abandonment of this procedure. The transglenoid suture technique developed by Morgan and popularized by Caspari was very successful for these investigators but was fraught with complications (including suprascapular nerve injury and tissue necrosis). It was nowhere near as successful when other arthroscopists used this technique, and failure rates as high as 44% have been reported.5 Next came bioabsorbable tacks, with failure rates of up to 20% and intracapsular synovial reactions in approximately 6% of cases.6 Current techniques, which typically involve suture anchors, have reduced the failure rates and complications, but double-digit recurrence rates are still commonly reported. If you look just at comparative studies between arthroscopic and open stabilization procedures, the average recurrence rate for arthroscopic procedures is approximately 15%, and the rate for open procedures is approximately 5%.7 Which rate would you prefer if it were your shoulder?
In summary, for a variety of reasons, open procedures for recurrent anterior shoulder instability continue to be the gold standard. Open procedures can better address capsular laxity, labral tears, rotator interval lesions, and bony defects. It is difficult to construct a long-term study of arthroscopic stabilization procedures because the procedures constantly change and newer techniques and devices are presented at every meeting and in every exhibitor booth. That is because they are constantly in need of improvement! Techniques for open Bankart repair and capsulorraphy do not change—because they have a long track record of success. To put it simply, they work! n
References
1. Bigliani L, et al. Tensile properties of the inferior glenohumeral ligament. J Orthop Res. 1992;10:187-197.
2. Miller MD, et al. Capsular volume reduction with open capsular shift procedures—A cadaveric study. J Shoulder Elbow Surg. In Press.
3. Field LD, et al. Isolated closure of rotator interval defects for shoulder instability. Am J Sports Med. 1995;23:557-563.
4. Johnson L. Diagnostic and Surgical Arthroscopy of the Shoulder. St Louis, MO: Mosby-Year Book; 1993:276-364.
5. Grana WA, et al. Arthroscopic Bankart suture repair. Am J Sports Med. 1993;21:348-353.
6. Edwards D, et al. Adverse reactions to an absorbable shoulder fixation device. J Shoulder Elbow Surg. 1994;30:230-233.
7. Cole BJ, Warner JJ. Arthroscopic versus open bankart repair for traumatic anterior shoulder instability. Clin Sports Med. 2000;19(1):19-48.
Although shoulder arthroscopy has become very popular and has been advocated for instability, there is often no substitute for an open procedure.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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