Application of the Goutallier/Fuchs Classification to the Evaluation of Hip Abductor Tendons Tears and the Correlation with Outcome Following Repair

Abstract

As in the shoulder, abductor tendon tears of the hip can lead to atrophy and fatty infiltration of the affected muscle belly. In this study we apply the Goutallier/Fuchs classification to the evaluation of tears involving the gluteus minimus and medius tendons, measure the reliability and reproducibility of this technique and assess for correlation between preoperative muscle grade and postoperative outcome. Preoperative MRI images of 30 consecutive hip abductor tears (27 females, 3 males) were retrospectively reviewed at three different time points by three independent observers, and the abductor muscles assigned a grade according to the Goutallier/Fuchs classification. All patients (mean 62 years) underwent endoscopic abductor tendon repair by a single fellowship trained surgeons. Patient-rated outcome scores including the Hip disability and Osteoarthritis Score (HOOS), modified Harris Hip Scale (mHHS) and Visual Analog Scale (pain) were collected pre and at a minimum of 2 years postoperatively. The intra- and interobserver reliability for muscle grading was calculated. Postoperative outcome measures were compared to preoperative muscle grading to assess for correlation. Over seventy-five percent of hips were classified as stage 1 (n = 15) or stage 2 (n = 8). Interobserver reliability and intraobserver repeatability of the classification technique averaged 0.872 and 0.916, respectively. Two patients (Grade 3 and 4) failed repair and underwent muscle transfer. In the remaining 28 hips, improvement was seen in VAS score (6.1 vs 1.7, p<0.005). The Goutallier/Fuchs classification system can be reliably and reproducibly applied to the evaluation of abductor tendon tears of the hip and appears to correlate with patient-rated outcome following repair.