Does the Femoral Cam Lesion Regrow After Osteoplasty for Femoroacetabular Impingement – Two Year Follow Up
Abstract
Objectives: Early skepticism of surgery for femoroacetabular impingement arose in part from suspicion that the cam lesion on the femoral head-neck junction would recur after initial resection. There are currently no studies that have looked at the recurrence of the cam lesion after femoral neck osteoplasty for femoroacetabular impingement (FAI). While Patient Related Outcome (PRO) scores at mid-term follow-up have shown continued success, the maintenance of a normalized alpha-angle has not been shown radiographically. The purpose of the study was to assess the radiographic recurrence of cam deformity at 2-year follow-up after adequate decompression during the index hip arthroscopy and correlate with PRO scores. Our hypothesis is there will be no recurrence or regrowth of the cam deformity at the two-year postoperative time-point following adequate cam decompression during hip arthroscopy.
Methods: Between March 2009 and January 2011 data was prospectively collected on all patients undergoing hip arthroscopy with femoral neck osteoplasty. Inclusion criteria consisted of all patients during the study period with preoperative alpha angles greater than 60 degrees and postoperative alpha angle less than 50 degrees after femoral osteoplasty. Minimum follow-up was two years with radiographic images for review.
Results: A total of 47 patients met inclusion criteria. The mean age of our study group was 37.18 (31.7 - 47.43) years at the start of the study. There were 28 males (59.57%) and 19 females (40.43%). The mean follow-up was 28.32 months. Mean preoperative alpha angle (Dunn view) was 70 degrees (60-97 degrees). At 2-week postoperative follow-up, the mean alpha angle was 42.79 degrees (32-50 degrees) (p<.0001). The 2-year alpha angle was 42.72 degrees (32-54 degrees) which was not significantly different compared to the 2-week alpha angle (p = 0.93). Additionally, mean preoperative femoral offset was 3.7 mm (0-9.9 mm). Mean two-week postoperative femoral offset measurement was 7.8 mm (0.3 -13.9 mm) which was significantly different (p<.0001). Two-year postoperative femoral offset measurement was 8.0 mm (2.4-12.8 mm) which was not significantly different compared to the 2-week femoral offset measurement (p = 0.63). All Patient Related Outcome (PRO) scores were significantly improved at 3 months compared to preoperative scores and continued to show improvement except for Visual Analog Scale (VAS) at 2-year follow-up.
Conclusions: There is no recurrence of cam deformity at 2-years following femoral neck osteoplasty for FAI with improved PRO scores at the 3-month and 2-year postoperative time-points.