Acetabular Subchondral and Cortical Perforation During Labral Repair With Suture Anchors: Influence of Portal Location, Curved Versus Straight Drill Guides, and Drill Starting Point

Abstract

To evaluate the impact of the portal used for drilling, the position of the drill guide on the acetabular rim, and the use of straight versus curved drill guides on drill perforation of the acetabular subchondral bone and the outer cortex of the acetabulum. Sixty acetabular models were marked at the 3-, 2-, 1-, 12-, and 11-o'clock positions. Simulated anterior, anterolateral, and distal anterolateral accessory (DALA) portals were created. Twelve groups of 5 acetabula were drilled at each clock-face position using all combinations of variables. A total of 38 of 300 drillings (12.7%) perforated the subchondral bone, and 45 of 300 (15%) breached the outer cortex. Drilling from the anterior, anterolateral, and DALA portals perforated the acetabular subchondral bone on 21 of 100 attempts (21%), 17 of 100 attempts (17%), and 0 of 100 attempts (0%), respectively (P < .001), and perforated the outer acetabular cortex on 36 of 100 attempts (36%), 1 of 100 attempts (1%), and 8 of 100 attempts (8%), respectively (P < .001). The use of a curved or straight drill guide did not make a statistically significant difference. Drilling with a starting point on the acetabular rim perforated the acetabular subchondral bone on 29 of 150 attempts (19.3%) compared with 9 of 150 attempts (6%) when the starting point was 2mm removed from the acetabular rim (P < .001). The use of the DALA portal and a drill starting point slightly off the acetabular rim was associated with the lowest rate of acetabular subchondral perforation and is recommended to reduce the risk of iatrogenic chondral injury. Iatrogenic chondral injury is a relatively common complication of hip arthroscopy. Increased awareness of factors associated with drill perforation during suture anchor placement can help surgeons mitigate this risk.