ePoster #500 - ISHA Annual Scientific Meeting 2016

Heterotopic Ossification Excision Following Hip Arthroscopy

John M. Redmond, MD, Westmont, IL UNITED STATES
Molly Keegan, MD, Jacksonville, FL UNITED STATES
Asheesh Gupta, MD, Woodridge, VA UNITED STATES
Jacob Worsham, MD, Jacksonville, FL UNITED STATES
Jon E. Hammarstedt, BS, Westmont, IL UNITED STATES
Benjamin G. Domb, MD, Chicago, IL UNITED STATES

American Hip Institute, Westmont, IL, UNITED STATES

FDA Status Not Applicable

Summary: Patients undergoing revision hip surgery with HO excision demonstrated improved outcome scores and pain resolution; however, few patients in this group achieved a good or excellent result and subsequent revision or conversion to total hip arthroplasty (THA) was seen in 21% of patients, indicating that revision hip surgery with HO excision should be approached cautiously.

Abstract:
Purpose: Heterotopic ossification (HO) is a well-known complication after surgery about the hip, including minimally invasive procedures such as hip arthroscopy. With the recent increase in arthroscopy this complication is expected to be more prevalent. The incidence of HO after hip arthroscopy is documented in the literature, but treatment and outcomes of symptomatic HO has yet to be defined. Revision surgery for refractory treatment of hip pathologies has risks to the patient and is costly, clear indications are required to prevent unnecessary intervention. The aim of this study is to determine if arthroscopic excision of potential symptomatic HO in revision cases improved the clinical outcome of the patient.
Descriptions of Methods: Outcome data from patients who had HO removed arthroscopically were prospectively collected and retrospectively reviewed between February 2008 and February 2014. A total of 2379 arthroscopic procedures were appraised to identify patient who underwent revision hip arthroscopy with removal of HO or loose body via CPT coding. Two hip fellows evaluated all radiographs to include patient who underwent removal of any HO that was one centimeter or greater on one view of orthogonal radiographs. Sixty eight patients were identified by CPT and 23 of those patient met radiographic criteria. A retrospective chart review was perform to ensure indication for revision was secondary look arthroscopy with HO excision. Exclusion criteria were revision with loose body removal, HO less than 1 cm, and patient who had previous hip conditions (Legg-Calves Perthes disease, avascular necrosis, or dysplasia). These records were evaluated for patient reported outcomes (PRO) measures: Modified Harris Hip Score (mHHS), Non-Arthritis Hip Score (NAHS), Hip Outcome Score – Activity of Daily Living (HOS-ADL), Sport-Specific Subscales (HOS-SSS), and visual analog scale (VAS). Demographics were included and follow up data including additional revision procedures.
Summary of Methods: Minimum 2.5 year follow up from index procedure was available for 23 patients with a mean age of 38.6 years. Of the 23 patients who had revision surgery and HO removal, 19 (83%) were available for follow up at 1.5 years. Prior to revision the average mHHS 53.4, HOS-ADL 51.4, HOS-SSS 24.5, NAHS 50.3, and VAS 6.7. Following revision with HO excision each score had improved with an average mHHS of 73.62, HOS-ADL of 68.88, HOS-SSS of 58.51, NAHS of 70.83, and VAS of 4.33. Overall, mHHS increased by 20.26 points, HOS-ALDS increased by 68.88 points, HOS-SSS increased by 34.03 points, NAHS increased by 20.55 points and VAS decreased by 2.38 points.
Conclusion: Patients undergoing revision hip surgery with HO excision demonstrated improved outcome scores and pain resolution. However, few patients in this group achieved a good or excellent result. Subsequent revision or conversion to total hip arthroplasty (THA) was seen in 21% of patients. Revision hip surgery with HO excision should be approached cautiously because of the modest results in this patient group.