Traditional Versus Congruent Arc Latarjet Technique: Effect on Surface Area for Union and Bone Width Surrounding Screws.

Purpose: To compare the surface area available for bony contact and the width of bone on each side of the Latarjet fixation screws in the traditional Latarjet technique versus the congruent arc modification of the Latarjet technique.

Methods: Computed tomographic scans of 24 shoulders in patients with glenohumeral instability who underwent multiplanar reconstruction measurements with multiple dimensions of the coracoid. The surface area of the coracoid available for bony contact with the anterior glenoid and width of bone on each side of a 3.5-mm screw was compared for the traditional Latarjet technique versus the congruent arc modification.

Results: The surface area available for bony contact to the anterior glenoid was 5.65 ± 1.08 cm using the traditional Latarjet technique compared with 3.64 ± 0.93 cm using the congruent arc modification of the Latarjet technique (P < .001). The mean width of bone on each side of a 3.5-mm screw was 7.1 ± 1.0 mm using the traditional Latarjet technique compared with 4.1 ± 1.0 mm using the congruent arc modification (P < .001).

Conclusions: The traditional Latarjet technique has greater bony contact with the glenoid and greater bone width on each side of the screws compared with the congruent arc modification of the Latarjet technique. This potentially allows for a larger surface for healing in the traditional Latarjet technique. Moreover, because of smaller width of the bone around the screw, the congruent arc modification is potentially less tolerant of screw-positioning error compared with the traditional Latarjet technique.

Level Of Evidence: Level III, retrospective comparative study.