Paper #65 - ISHA Annual Scientific Meeting 2016

Results of Hip Arthroscopy in Patients with MRI Diagnosis of Sub-Chondral Cysts - A Case Series

David E. Hartigan, MD, Westmont, IL UNITED STATES
John M. Redmond, MD, Westmont, IL UNITED STATES
Itay Perets, MD, Westmont, IL UNITED STATES
Mary R. Close, BS, Westmont, IL UNITED STATES
Edwin Chaharbakhshi, BS, Hinsdale, IL UNITED STATES
John P. Walsh, MA, Westmont, IL UNITED STATES
Benjamin G. Domb, MD, Chicago, IL UNITED STATES

American Hip Institute, Westmont, IL, UNITED STATES

FDA Status Not Applicable

Summary: Hip arthroscopies performed on patients with sub-chondral cysts present on preoperative MRI should be approached with caution.

Abstract:
Purpose: To examine the results of arthroscopic management of patients with labral pathology who have preoperative MRIs demonstrating sub-chondral cysts.
Methods: This institution’s database was searched for patients who underwent hip arthroscopy that had sub-chondral cysts on MRI and >two-year follow-up. Exclusion criteria included previous hip surgery, Tönnis grade >1, inflammatory arthritis, Perthes, SCFE, or abductor repair. Patient reported outcome (PRO) scores were gathered on all hip arthroscopy patients, including VAS, mHHS, NAHS, and HOS-SSS preoperatively, at three months, and annually thereafter. The change in PRO scores were compared to the minimally clinical important difference (MCID) to quantify improvement.
Results: Of the 1,517 hip scopes performed between February 2008 and March 2013, 69 patients were eligible for this study. There were 65 (94%) that had >two-year clinical follow-up. The VAS, mHHS, NAHS, and HOS-SSS improved from 5.2, 64, 61, and 41 to 2.8, 76, 80, and 63 respectively (p<0.001). The average patient satisfaction was 7.2 at >2-year follow-up. There was no correlation with Outerbridge grade III or IV cartilage damage noted during arthroscopy and sub-chondral femoral and acetabular cysts noted on MRI. There were 17 patients that required reoperation, of these 13 required THA, and four required revision arthroscopy. Patients with femoral subchondral cysts required a conversion to a THA 36% of the time. MCID for mHHS and HOS-SSS were surpassed by 63% and 68% of patients respectively.
Conclusion Hip arthroscopies performed on patients with sub-chondral cysts present on preoperative MRI should be approached with caution. The rate of conversion to hip arthroplasty appears to be higher than that reported in the literature for patients who undergo arthroscopy without preoperative subchondral cysts. For patients who did not require hip arthroplasty or revision arthroscopy, patients demonstrated significant improvement in symptoms compared to the preoperative state.