Surgical Technique: Arthroscopic Osteoplasty of Anterior Inferior Iliac Spine for Femoroacetabular Impingement.

The anterior inferior iliac spine (AIIS) has variable morphology that correlates with hip range of motion. Subspinal impingement is an extracapsular cause for femoroacetabular impingement (FAI) and is clinically significant because it results in decreased range of motion and groin pain with flexion-based activity. In symptomatic patients with AIIS extension to or below the acetabular rim, AIIS decompression is considered part of an FAI corrective procedure. A consistent exposed bony area on the anterior and inferomedial aspect of the AIIS serves as a "safe zone" of resection allowing for decompression with preservation of the origin of the rectus femoris tendon. This surgical note describes a technique for AIIS decompression. The goal for low AIIS osteoplasty is to resect the AIIS to 2 burr widths (using a 5.5-mm burr) above the acetabular rim, achieving an 11-mm clearance, creating a type I AIIS. The resultant flat anterior acetabular surface between the most anteroinferior prominent point of the AIIS and the acetabular rim allows for free movement of the hip joint without impingement. Careful execution of AIIS decompression can alleviate clinical symptoms of FAI and restore function to the hip joint.