Purpose: To compare a curved drill guide with a straight guide for suture anchor placement into the posterosuperior glenoid from an anterolateral portal with respect to glenoid perforation, drill contact with the suprascapular nerve, and maximum load.
Methods: Ten bilateral pairs of fresh human cadaveric shoulders were randomized to the curved technique on 1 side and the straight technique on the contralateral side. An anterolateral trans-rotator cuff portal was used for placement of anchors at the posterior (11 o'clock right shoulder) and far posterior (10 o'clock right shoulder) positions on the glenoid with a 24-mm drill stop, and the drill tip was marked with ink. Specimens were dissected for glenoid perforation and drill contact with the suprascapular nerve. The maximum load of each anchor was measured using a material testing system.
Results: Glenoid perforation occurred in 30% in the curved group and 60% in the straight group overall (P = .01). Ink markings demonstrated a direct hit on the suprascapular nerve in most of the penetrations (13 of 18) but was not significantly different between the curved and straight guides (P = .25). Maximum load of the posterior anchor was greater in the curved group than that in the straight group (199.5 vs 146.7 N, respectively; P = .01).
Conclusions: The curved technique has a lower rate of glenoid perforation and greater maximum load than the straight technique. However, the curved technique can result in glenoid perforation and injury to the suprascapular nerve, and we do not recommend it.
Clinical relevance: Placing suture anchors through an anterolateral portal with a curved guide provides a more optimal trajectory with decreased risk of glenoid perforation and superior biomechanical strength than that with the straight guide, but it is not safe.
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