What factors influence long-term survivorship after hip arthroscopy?

Abstract

Background: Hip arthroscopy is an evolving procedure. One small study suggested that a low modified Harris hip score and arthritis at the time of surgery were predictors of poor prognosis.

Questions/purposes: We therefore intended to confirm those findings with a large patient cohort to (1) determine the long-term nonarthritic hip score; (2) determine survivorship; (3) identify risk factors that increase the likelihood of THA; and (4) use those factors to create a usable risk assessment algorithm.

Patients and methods: We retrospectively reviewed 324 patients (340 hips) who underwent arthroscopy for pain and/or catching. Of these, 106 patients (111 hips or 33%) had a minimum followup of 10 years (mean, 13 years; range, 10-20 years). The average age was 39 years (± 13) with 47 men and 59 women. We recorded patient age, gender, acetabular and femoral Outerbridge grade at surgery, and the presence of a labral tear. Followup consisted of a nonarthritic hip score or the date of a subsequent THA. We determined survivorship with the end point of THA for the acetabular and femoral Outerbridge grades.

Results: Overall survivorship among the 111 hips was 63% at 10 years. The average nonarthritic hip score for non-THA patients was 87.3 (± 12.1). Survivorship was greater for acetabular and femoral Outerbridge grades normal through II. Age at arthroscopy and Outerbridge grades independently predicted eventual THA. Gender and the presence of a labral tear did not influence long-term survivorship.

Conclusions: The long-term survivorship of labral tears with low-grade cartilage damage indicates hip arthroscopy is reasonable for treating labral tears.

Level of evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Fig. 1

The Kaplan-Meier estimated survivorship for the subset (n = 111) of the entire cohort (324) using THA as an end point was 91% (86%–96%) at 1 year, 75% (68%–82%) at 5 years, and 63% (55%–71%) at 10 years. Numbers in parentheses at the bottom are patients who did not have THA and were still being followed.

Fig. 2

The Kaplan-Meier estimated survivorship for the followup cohort divided into low-grade (n = 79, 20 THAs) and high-grade (n = 32, 29 THAs) groups based on acetabular Outerbridge grade using THA as an end point showed a decrease in 10-year survivorship for the high grades (22% [9%–35%]) compared with the low grades (80% [71%–89%], p < 0.001, log-rank test = 59.75).

Fig. 3

The Kaplan-Meier estimated survivorship for the followup cohort divided into low-grade (n = 84, 23 THAs) and high-grade (n = 27, 26 THAs) groups based on femoral Outerbridge grade using THA as an end point showed a decrease in 10-year survivorship for the high grades (12% [2%–22%]) compared with the low grades (80% [72%–88%], p < 0.001, log-rank test = 72.72).

Fig. 4

The Kaplan-Meier estimated survivorship for a subgroup of the followup cohort, which had a labral tear and a low Outerbridge grade (normal to Grade II) on both the femoral and acetabular side using THA as an end point showed a 90% (80%–100%) survivorship at 5 and 10 years postoperatively. Numbers in parentheses at the bottom are patients who did not have THA and were still being followed.