Prognostic value of magnetic resonance arthrography for Czerny stage II and III acetabular labral tears.

PURPOSE: To assess the intraobserver reliability and prognostic value of magnetic resonance arthrography (MRA) on the basis of postoperative outcome measures following arthroscopic acetabular labral debridement (partial limbectomy).

METHODS

Between January 1999 and November 2000, 24 patients (13 females, 11 males) with an average age of 37.1 years (range, 21 to 56 years) underwent hip arthroscopy for the treatment of presumed acetabular labral tears. All patients underwent preoperative MRA and/or magnetic resonance imaging (MRI); images were evaluated by a single musculoskeletal radiologist on 2 independent occasions. Hip arthroscopy was performed on all patients. Outcomes were assessed by means of the Modified Harris Hip Score (MHHS) and the Short Form-36 (SF-36) questionnaires, which were completed by patients an average of 24.1 months (range, 12 to 55 months) postoperatively. The accuracy of the initial read, as well as the prognostic value of the Czerny MRA classification system for stage II (intrasubstance tears) and stage III (complete avulsions) acetabular labral tears, was assessed.

RESULTS

Twenty-two of 23 tears (96%) were detected on the initial read. On the basis of intraoperative findings, 1 false-positive MRA, 1 false-negative MRA, and 1 incident of MRA overstaging were reported. On repeat interpretation, 23 of 23 (100%) tears were identified, and intraobserver reliability for recording the presence of a tear was excellent (kappa coefficient = 0.96). No difference was noted in outcomes between patients with or without arthroscopic evidence of chondromalacia (all P > .29), or between patients older or younger than 30 years (all P > .34). Likewise, no difference in outcome was seen between 15 patients with Czerny stage II tears revealed on MRA versus 9 patients with Czerny stage III tears (all P > .79).

CONCLUSIONS

MRA is sensitive and accurate for the detection of acetabular labral tears, with excellent intraobserver reliability. Arthroscopic partial limbectomy is successful in two thirds of patients. Patients with Czerny stage II and III tears do not appear to have significantly different outcomes following arthroscopic labral debridement.

LEVEL OF EVIDENCE: Level IV, prognostic case series.