Safe Angle of Anchor Insertion for Labral Repair During Hip Arthroscopy.

PURPOSE To compare the use of the distal anterolateral accessory (DALA) portal with the anterolateral (AL) and midanterior (MA) portals during arthroscopic hip labral repair. METHODS Standard AL, MA, and DALA portals were created on 6 cadaveric hip specimens. Four 2.4-mm pins were placed in the acetabular rim to the depth of a standard anchor using a drill guide. Pins were placed in the 12 to 3 o'clock positions. The specimens then underwent computed tomographic scans with the pins left in place, and the distance from the pin to the articular surface was calculated at different depths of insertion. RESULTS In the anterior location, the average starting distance for the DALA pin was 2.05 mm and for the MA pin it was 2.51 mm from the articular surface (P = .29). Statistically significant differences between the DALA and MA pins were found at depths of 6 mm (P = .04) and 9 mm (P = .03). In the superior location, the average starting distance for the DALA pin was 2.40 mm and for the AL pin it was 2.62 mm from the articular surface (P = .34). Statistically significant differences between the DALA and AL pins were found at depths of 6 mm (P = .02), 9 mm (P = .01), 12 mm (P = .01), 15 mm (P = .04), and 18 mm (P = .04). CONCLUSIONS The DALA portal allows pins to be placed at a greater distance from the articular surface than the MA and AL portals when using a straight drill guide. This may decrease the incidence of intra-articular penetration during arthroscopic hip labral repair. CLINICAL RELEVANCE Intra-articular penetration of a drill bit or anchor is an iatrogenic complication that can occur during labral repair. By using the DALA portal instead of the AL and MA, the anchor can be safely placed on the acetabular rim and directly away from the articular surface, decreasing the chance for this complication.