Preoperative MRI and Intraoperative Arthroscopic Evaluation of Chondral Pathology at the Hip Chondrolabral Junction.

Background: Previous literature has found that hip magnetic resonance imaging (MRI) has lower accuracy and reliability in preoperative diagnosis of cartilage and labral pathology compared with knee and shoulder MRI. This is a notable limitation, as MRI findings play a significant role in the determination for surgical intervention in femoroacetabular impingement syndrome (FAIS) and aid in surgical planning, intraoperative cartilage management, and in postoperative rehabilitation expectations. Indications: Hip arthroscopy is most commonly utilized for the treatment of FAIS and associated labral tears and chondral pathology of varying grades, particularly at the chondrolabral junction. Given the difficulty in assessing chondrolabral pathology on preoperative MRI, we present our preferred method of correlating MRI to intraoperative findings at the chondrolabral junction. Technique Description: Using preoperative MRI and the Outerbridge classification system, we describe our method to assess cartilage injuries and chondrolabral junction pathology in patients who undergo hip arthroscopy for FAIS. We correlate chondral injuries with preoperative MRI to aid surgeons in interpreting the degree of chondral injury from MRI and corresponding surgical findings. Results: Given that MRI of the hip is neither as accurate nor as reliable as MRI of the knee or shoulder, an understanding of how to correlate preoperative MRI with intraoperative appearance can better prepare the surgeon for findings at the chondrolabral junction of the hip. The absence of findings on MRI does not rule out the possibility of cartilage or labral pathology. Discussion/Conclusion: Intraoperatively, hip cartilage is assessed using either the Outerbridge or Beck classification systems. These classification systems require direct visualization of the hip joint, and full assessment of the chondrolabral junction and associated pathology may not be possible until intra-articular work is complete. While MRI evaluation of the hip is difficult due to the depth of the hip joint, location of the hip relative to the MR magnet, and thinness of the acetabular cartilage, it is a useful tool for preoperative hip joint cartilage assessment, though not as accurate as knee and shoulder MRIs. Understanding the correlation between preoperative hip MRI and intraoperative chondrolabral pathology can aid the surgeon in preparation for hip arthroscopy in the treatment of FAIS.