Technique Spotlight: Arthroscopic Latarjet

Glenoid Bone Loss

Many authors have reported failure of soft tissue repairs in the setting of glenoid bone loss. ^, The mechanical consequences of anteroinferior glenoid erosion are significant, and even a relatively small amount of bone loss can significantly affect the recurrence rate after arthroscopic or open soft tissue (Bankart) repair. A detailed discussion of the different options for assessment of the glenoid and humeral lesions is found in Chapter 19 . In summary, assessment of the degree of bone loss can be made through a variety of methods including plain radiographs, specific magnetic resonance imaging (MRI) sequences, computed tomography (CT) scan with 3D volume rendering, arthroscopic assessment and measurement. ^, CT reconstructions provide a robust static measurement of bone loss. Arthroscopically, the distance from the glenoid rim as measured from the bare spot can assist the surgeon in identifying an inverted pear glenoid confirming substantial bone loss and the likely failure of an isolated soft tissue repair.

In some cases, the bony fragment can be replaced and arthroscopically repaired by anchors and sutures. However, this fragment is often comminuted, partially or completely resorbed over time, and may have poor healing potential. Furthermore, suture fixation is not as rigid as two screws with solid, cortical fixation. In these cases, a bone reconstruction as performed by the Latarjet procedure should be considered.

Humeral Bone Loss

The location and the depth of the Hill-Sachs lesion is variable with each case: sometimes small and superficial, sometimes large and/or deep, and rarely double. Its location and depth is responsible for persistent instability, even in cases of a well done Bankart repair. ^, Its precise assessment is difficult but can be approached by simple X-ray in internal rotation and 2D or 3D CT scan. The “remplissage” of the infraspinatus tendon has been described with satisfactory results but external rotation may be limited and long-term results have not been reported.

The location and size of the Hill-Sachs lesion determines whether the articular arc is reduced and whether this will engage on the glenoid. A dynamic arthroscopy with the shoulder in abduction and external rotation will demonstrate whether the lesion is engaging even within an athletic overhead range of movement. A bone block procedure here will increase the arc of the anterior glenoid thereby increasing the degree of external rotation that can be achieved before the Hill-Sachs lesion approaches the glenoid rim. We believe that by enlarging the glenoid articular arc with a bone graft, stability can be achieved without addressing the Hill-Sachs lesion directly.

Bipolar Bone Loss

The “bipolar lesion” is responsible for many cases of recurrent instability. This combination of two lesions usually occurs with varying degrees of severity for each individual lesion. These can be assessed before the procedure by examination, plain radiographs, and CT scan. It is critical to look for both lesions during the diagnostic portion of the arthroscopy under dynamic visualization.

Revision of Bankart Repair

After an open or arthroscopic Bankart repair, success is often measured by the absence of recurrent dislocations. In some cases, the joint is incompletely stabilized but may allow function for a more sedentary lifestyle without overt symptoms of instability. This can, in part, explain the excellent results seen in series with a short follow-up. After 5 to 7 years we find this particular group of patients can go on to develop instability and/or arthritis. In these cases, the initial operation was considered successful although the pathological lesion was never truly corrected and the glenoid subsequently becomes increasingly eroded. Again, these patients can be successfully managed with a Latarjet procedure.