The Arthroscopic Treatment of Traumatic Anterior Instability

Stephen S. Burkhart, M.D.
San Antonio, Texas, USA

With the transition away from transglenoid suture techniques and the implementation of suture anchor techniques, the results of arthroscopic Bankart repair have improved tremendously. At its best, transglenoid repair had a 13-percent failure rate at long-term follow-up (McIntyre and Caspari), and the worst results had recurrence rates in the 40 percent to 60 percent range.

Suture anchor repairs are now routinely reporting recurrence rates of less than 10 percent, in line with the results of the "gold standard" open Bankart technique. Even so, there continues to be a great deal of research directed at improving these results further. Much of the effort is focused on adjunctive measures of capsular reduction, such as capsular plication, rotator interval closure and radiothermal capsular shrinkage. These are all strictly soft tissue techniques.

Dr. Joe DeBeer and I recently completed a study, soon to be published in Arthroscopy, examining the relationship of failure of arthroscopic Bankart repair to traumatic glenohumeral bone defects. We reviewed 194 cases of arthroscopic Bankart repair by suture anchors and divided them into two groups as follows:

Group 1 (173 patients):

• No significant bone defect
• Recurrence rate 4 percent

Group 2 (21 patients):

• Significant bone defect
• Recurrence rate 67 percent

We defined and subdivided significant bone defects into two categories:

1. Glenoid "Inverted Pear"
   • Inferior glenoid diameter less than superior glenoid diameter
   • Greater than 25-percent loss of inferior glenoid articular arc
2. Humeral "Engaging Hill-Sachs Lesion"
   • Hill-Sachs lesion that could be observed arthroscopically to engage the anterior glenoid rim in parallel fashion when the shoulder was brought into 90° abduction and 70° to 100° external rotation

The "non-engaging Hill-Sachs lesions" (i.e., those that passed diagonally across the glenoid with the arm in abduction and external rotation) did not have an increased rate of recurrence.

In contact athletes (101 patients), if there was a significant bone defect, there was a recurrence rate of 87 percent. However, if there was not a significant bone defect, the recurrence rate was only 6.5 percent. This data would indicate that a contact athlete without a bone defect might reasonably be considered for an arthroscopic repair.

We concluded that arthroscopic Bankart results were equal to open Bankart results if there were no significant bone defects. We also concluded that the two patterns of bone deficiency that are contraindications to arthroscopic Bankart repair are the "inverted pear glenoid"and the "engaging Hill-Sachs lesion." For patients with severe glenoid deficiency, we recommend restoration of the glenoid articular arc with a large coracoid bone graft (Latarjet procedure).

The focus on bone loss is a departure from the current trend of addressing only the capsule, even to the point of overtightening or overconstraining the capsule. My concern with overtightening is that it will create stiff shoulders that, even though they may not sustain recurrent dislocations, will have sub-optimal and possibly unacceptable function. Our goal should be to produce stable shoulders, not stiff shoulders.