In this retrospective study, Kartus et al. report on a series of patients with anterior shoulder instability who were treated with arthroscopic placement of extra-articular absorbable tacks. The greatest value of this study lies in the long-term clinical and radiographic results of a nonanatomic variant of the arthroscopic Bankart repair. Although not clearly stated, the study appears to report longer-term follow-up of a group of patients reported previously at two to five years following surgery1. The data are particularly pertinent today as we continue to define outcomes of arthroscopic instability repairs and refine our surgical techniques to match the clinical results of open Bankart repairs.
The study includes a consecutive series of seventy-one patients who had recurrent posttraumatic anterior shoulder instability that was treated by a single surgeon with use of bioabsorbable tacks. The patients were followed for seven to ten years postoperatively. In accordance with the prior study, the clinical and radiographic assessments were performed by blinded examiners who were not involved with the initial care of the patients. The use of independent examiners, the low attrition rate (12%), and the long-term follow-up (a minimum of seven years) are clearly the strengths of the study.
The authors noted an alarmingly high rate of recurrent instability (38% of subjects), the majority of which occurred more than two years following surgery. The authors should be commended for their strict definition of recurrent instability, which included patients with recurrent dislocations and subluxation episodes, even when occurring as an isolated event. Of interest, approximately half of the patients with recurrent instability experienced a substantial traumatic event, highlighting the importance of activity and lifestyle as prognostic factors for recurrent instability following surgery.
The high rate of recurrent instability in this series is likely influenced not only by the inclusive definition of instability employed by the authors but also by the surgical technique and criteria for patient selection. The current focus in performing arthroscopic Bankart repair procedures that utilize suture anchors is to reestablish the anteroinferior capsulolabral bumper and to perform selective tensioning of the inferior glenohumeral ligament and anterior capsule2,3. The surgical technique utilized in these patients focuses on repair and tensioning of the detached glenohumeral ligaments; however, repair of the normal anteroinferior portion of the labrum was not performed. Seventy-six percent of the patients were noted to have complete detachment of the anteroinferior portion of the labrum at the time of surgery. The labral complex has been well recognized to contribute to stability of the glenohumeral joint by minimizing translational movements of the humeral head, and its effect is augmented by compressive forces imparted to the joint from the rotator cuff muscles4.
Of note, the authors made no attempt to quantify or classify glenoid bone loss in this patient population. Such a finding would be of interest because a significant percentage (p < 0.0001) of patients with posttraumatic recurrent anterior instability will have some measurable bone loss of the anterior glenoid rim that may contribute to recurrent instability5,6, especially when there is no attempt to restore the anterior capsulolabral "bumper."
In conclusion, this study provides valuable insight into the outcomes of patients with recurrent anterior instability treated with arthroscopic extra-articular repairs. The authors should be commended for critically defining recurrent instability and reporting long-term results. However, the high recurrence rate of instability in this series should not be extrapolated to all arthroscopic Bankart repairs, considering the nonanatomic nature of the surgical technique.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the author, or a member of his immediate family, is affiliated or associated.
1. Kartus J, Kartus C, Povacz P, Forstner R, Ejerhed L, Resch H. Unbiased evaluation of the arthroscopic extra-articular technique for Bankart repair: a clinical and radiographic study with a 2- to 5-year follow-up. Knee Surg Sports Traumatol Arthrosc. 2001;9:109-15.
2. Lazarus MD, Sidles JA, Harryman DT 2nd, Matsen, FA 3rd. Effect of a chondral-labral defect on glenoid concavity and glenohumeral stability: a cadaveric model. J Bone Joint Surg Am. 1996;78:94-102.
3. Sugaya H, Moriishi J, Dohi M, Kon Y, Tsuchiya A. Glenoid rim morphology in recurrent anterior glenohumeral instability. J Bone Joint Surg Am. 2003;85:878-84.
4. Itoi E, Lee SB, Berglund LJ, Berge LL, An KN. The effect of a glenoid defect on anteroinferior stability of the shoulder after Bankart repair: a cadaveric study. J Bone Joint Surg Am. 2000;82:35-46.
5. Boileau P, Villalba M, Héry JY, Balg F, Ahrens P, Neyton L. Risk factors for recurrence of shoulder instability after arthroscopic Bankart repair. J Bone Joint Surg Am. 2006;88:1755-63.
6. Kim SH, Ha KI, Cho YB, Ryu BD, Oh I. Arthroscopic anterior stabilization of the shoulder: two to six-year follow-up. J Bone Joint Surg Am. 2003;85:1511-8.