Outcomes After Management of Subspine and Femoroacetabular Impingement Using a Direct Anterior Mini-Open Approach

Abstract

Background: Subspine impingement (SSI) has been commonly managed with arthroscopic decompression. However, arthroscopic decompression is a demanding technique, as under- or over-resection of the anterior inferior iliac spine (AIIS) could lead to inferior outcomes. An anterior mini-open approach has also been used in the management of femoroacetabular impingement (FAI), and it could provide adequate visualization of the anterior hip joint without a long learning curve. Purpose/Hypothesis: The objective of the current study was to compare the outcomes of SSI patients with FAI who underwent arthroscopic subspine decompression and osteoplasty with a group undergoing subspine decompression and osteoplasty using a modified direct anterior mini-open approach. It was hypothesized that there would be no significant difference in outcomes between the groups. Study Design: Cohort study; Level of evidence, 3. Methods: We reviewed the records of SSI patients who underwent decompression surgery (arthroscopic or mini-open) at our institution from June 1, 2015 to December 31, 2016. Both groups underwent the same postoperative rehabilitation protocol. Preoperative and 2-year postoperative patient-reported outcomes were compared using the modified Harris Hip Score (mHHS), International Hip Outcome Tool–33 (iHOT–33), and Hip Outcome Score—Activities of Daily Living (HOS–ADL). Major and minor complications as well as reoperation rates were recorded. Results: Included were 47 patients (49 hips) who underwent subspine decompression using an anterior mini-open approach and 35 patients (35 hips) who underwent arthroscopic subspine decompression. There were no differences in demographic and radiological parameters between the groups, and patients in both groups showed significant improvement in all outcome scores at follow-up. The pre- to postoperative improvement in outcome scores was also similar between groups (mini-open vs arthroscopy: mHHS, 26.30 vs 27.04 [ P = .783]; iHOT–33, 35.76 vs 31.77 [ P = .064]; HOS–ADL, 26.09 vs 22.77 [ P = .146]). In the mini-open group, 10 of the 47 patients had temporary meralgia paresthetica, and fat liquefaction was found in 1 female patient. There were no reoperations in the mini-open group. Conclusion: Subspine decompression using the anterior mini-open approach had similar outcomes to arthroscopic decompression in the management of SSI. The lateral femoral cutaneous nerve should be protected carefully during use of the anterior mini-open approach.