ePoster #101 - ISHA Annual Scientific Meeting 2016

Morphologic Matrix for Mechanical Hip Pain: Classification System, Intra-Operative Findings, and Outcomes Following Arthroscopic Surgery

Eilish O'sullivan, PT, DPT, OCS, SCS, New York, NY UNITED STATES
Asheesh Bedi, MD, Ann Arbor, MI UNITED STATES
Bryan Talmadge Kelly, MD, New York, NY UNITED STATES

Hospital for Special Surgery, New York, NY, UNITED STATES

FDA Status Not Applicable

Summary: Intra-operative finding associated with the Matrix are reported, and the patient-reported outcome scores associated with them following arthroscopic management of patients with non-arthritic mechanical hip pain.


The Morphologic Matrix utilizes radiographic parameters to classify patients with mechanical hip pain. We describe the intra-operative finding associated with the matrices, and the patient-reported outcome scores associated with them following arthroscopic management of patients with non-arthritic mechanical hip pain.


A retrospective analysis was conduct from a prospectively enrolled Hip Preservation Registry with available computed tomography (CT) data undergoing hip arthroscopy for mechanical hip pain between October 2010 and July 2014. Surgery was indicated for labral injury and femoroacetabular impingement. The Matrix is built from the coronal center edge angle, maximum alpha angle, and femoral version as measured on CT. The profiles range from that of instability (with low center edge angle, no cam morphology, and increased femoral anteversion), to the arthroscopic safe zone, to that of severe impingement (significant acetabular overcoverage, severe cam deformity, and femoral retroversion). Intra-operative findings including the presence of transition zone delamination, femoral and acetabular cartilage injury, whether or not cam, rim, and/or subspine decompression was performed, labral debridement versus refixation, along with capsular closure. Patient reported outcomes including Modified Harris Hip Score, Hip Outcome Score, and iHOT-33 were examined in those who had greater than or equal to two years follow up. Those requiring subsequent revision surgery (arthroscopic or open) were also noted.


Criteria were met for 1077 patients (1330 hips), 60% were male, and 78% of the patients were between the ages of 16-39 years of age. 55% of patients were distributed in 4 of 48 possible categories. 2 of the categories with the greatest frequency distribution were those best suited for arthroscopic management, or the “arthroscopic safe zone.” There were significant differences in category distributions with respect to sex according to Chi-square test (p<0.001), with females predominating the instability end of the spectrum, and males the impingement end. There were significant differences in the procedures carried out, and intra-articular injury pattern. 514 patients had both pre- and post-operative scores greater than or equal to 2 years, with average follow up of 32.8 months. Average pre-operative and post-operative scores for this group were pre-op mHHS 63.3 (SD 13.1) and post-op 85.1 (SD 15.2), HOS ADL pre-op 75.54 (SD 15.6) and 91.39 (SD 12.3), HOS Sport pre-op 52.52 (SD 24.2) and post-op 80.65 (SD 23.9), and iHOT pre-op 42.56 (SD 18.1) and post-op 74.62 (SD 23.6). All groups improved significantly (p<0.05) in mHHS, HOS, and iHOT-33, but both pre-operative and post-operative scores were lower for female patients. The greatest incidence of revision (n=7) in a category with greater than 20 patients was the category consisting of slight acetabular undercoverage, small cam, and normal femoral version (222), and was predominantly female.


The Matrix is a classification method for those patients with mechanical hip pain that may aid in identifying the best-suited candidates for arthroscopic management of mechanical hip pain. Significant improvements in patient-reported outcomes were seen in all groups.