Does arthroscopic FAI correction improve function with radiographic arthritis?

Abstract

Background: Previous studies reporting the impact of osteoarthritis (OA) on pain and function after hip arthroscopy largely predate resection of femoroacetabular impingement (FAI).

Questions/purposes: We determined (1) functional improvement after resection of FAI impingement lesions in patients with preoperative radiographic joint space narrowing, and (2) identified preoperative predictors of pain, function, and failure rates in these patients.

Patients and methods: Between September 2004 and April 2008, we treated 210 patients (227 hips) with FAI and a minimum 12-month followup (mean, 27 months). Group FAI consisted of 154 patients (169 hips) without radiographic joint space narrowing, whereas Group FAI-OA consisted of 56 patients (58 hips) with preoperative radiographic joint space narrowing. We collected Harris hip scores (HHS), Short Form-12 (SF-12), and pain scores on a visual analog scale (VAS) preoperatively and postoperatively.

Results: Score improvements were better for Group FAI compared with Group FAI-OA. The overall failure rate was greater for Group FAI-OA (52%) than for Group FAI (12%). Although patients with less than 50% joint space narrowing or greater than 2 mm joint space remaining on preoperative radiographs had improved scores throughout the study, we observed no score improvements at any time with advanced preoperative joint space narrowing. Greater joint space narrowing, advanced MRI chondral grade, and longer duration of preoperative symptoms predicted lower scores.

Conclusion: FAI correction with milder degrees of preoperative radiographic joint space narrowing resulted in improvements in pain and function at short-term followup. Patients with advanced radiographic joint space narrowing do not improve and we believe should not be considered for arthroscopic FAI correction.

Fig. 1A–B

Preoperative AP radiographs show (A) a patient with FAI without substantial degenerative changes (Group FAI), and (B) a patient with FAI and advanced focal joint space narrowing (Group FAI-OA) superiorly with a large femoral head-neck impingement cyst (arrow).

Fig. 2A–D

Preoperative and postoperative radiographs show the management of pincer and cam-type FAI. (A) A preoperative radiograph of a 25-year-old woman shows bilateral pincer-type FAI secondary to global overcoverage and labral ossification (arrows). (B) Her postoperative radiograph is shown after left hip global rim resection (arrow). (C) A preoperative lateral radiograph shows a 20-year-old man with cam-type FAI (arrow). (D) His postoperative radiograph shows improved head-neck offset after femoral resection osteoplasty (arrow).

Fig. 3

This graph shows the mean HHS at each time for Group FAI and Group FAI-OA. p Values are placed directly above each group’s bar at different times (* = p < .001). Each p value corresponds to improvement in the HHS between that individual bar and the preoperative value.

Fig. 4

This graph shows the mean failure rates at each time for Groups FAI (Tönnis Grades 0–1), mild to moderate OA (< 50% joint space narrowing or > 2 mm joint space remaining), and advanced OA (> 50% joint space narrowing or < 2 mm joint space remaining). p Values are placed directly above the each group’s bar at different times (* = p < .001). Each p value corresponds to improvement in failure rates between that individual bar and the preoperative value.

Fig. 5

The graph shows the mean HHS for Groups FAI (Tönnis Grades 0–1), mild to moderate OA (< 50% joint space narrowing or > 2 mm joint space remaining), and advanced OA (> 50% joint space narrowing or < 2 mm joint space remaining). p Values are placed directly above the each group’s bar at different times (* = p < .001). Each p value corresponds to improvement in HHS between that individual bar and the preoperative value.