CORR Insights®: Good Outcome Scores and Low Conversion Rate to THA 10 Years After Hip Arthroscopy for the Treatment of Femoroacetabular Impingement

Femoroacetabular impingement (FAI) causes hip pain, impairs hip function, and is considered a risk factor for osteoarthritis [⁶].

Hip preservation surgeons generally treat symptomatic FAI with surgery. Arthroscopic techniques are more frequently employed than open ones [⁹]. Arthroscopic treatment produces better results than physical therapy alone, at least in the short term [⁷]. In a propensity-based analysis of the prospective ANCHOR cohort comparing arthroscopic treatment with surgical dislocation, Nepple et al. [¹⁰] found no major differences in patient-reported outcomes measures (PROMs), risk of conversion to THA, or proportion of patients reporting persistent symptoms at a mean follow-up of 4 years [¹⁰]. These 4-year results are important because they suggest that the more recent, less-invasive arthroscopic approach may offer similar results to open surgery and therefore may be considered a therapeutic advancement.

In the first two decades since surgeons have more widely recognized FAI and treated it surgically, clinical research has mainly been observational, and it has used older outcomes tools (when outcomes-reporting tools were used at all). Imaging analysis has most commonly employed static radiography and static MRI of the labrum and cartilage. In addition, researchers have reported generally shorter follow-up times, resulting in clinicians having little confidence about the disease-modifying effects of treatments, if any. After all, the morphologies that cause FAI exert their influence over many decades.

Most centers treating FAI with hip preservation surgery now employ PROM tools for the relatively young active population. Many centers use iHOT-33, a 33-question survey on “symptoms and functional limitations, sports and recreational activities, job-related concerns, and lifestyle concerns” [²]. iHOT-33 is favored for young, active populations because of the lack of ceiling effects and its reference to social and emotional domains as well as physical domains.

There also is increasing acceptance of nonorthopaedic factors on patient-perceived outcomes [^{4, 8}]. Today, complex imaging of the patient with symptomatic FAI often includes information on both femoral and acetabular versions, since this parameter can influence impingement and stability and treatment outcomes [⁵].

The study in this month’s Clinical Orthopaedics and Related Research® by Büchler et al. [¹] on the early Bernese arthroscopic experience in treating FAI reflects many of the important issues in the field. Though the treated group was largely women and the surgical techniques reported are not contemporary, the results are reassuring. Before surgery, 71% of patients (37 of 52 hips) were in in the fair-to-poor category by Merle d’Aubigné-Postel Score (< 15). But at the last follow-up, only 15% (7 of 47 hips) were rated fair-to-poor.

Based on these discoveries, surgeons should consider arthroscopic approaches as a first choice for well-selected patients with impaction and inclusion impingement, assuming that both the patient and team are well prepared.