Discussion
In this study, we collected epidemiologic data (demographics, pathologic entities treated, patient-reported measures of disease, surgical treatment preferences) from a large multicenter population of hip pathology patients who elected to undergo arthroscopic surgery. Our results showed these patients were most commonly younger to middle-aged white females with pain primarily in the groin region. Most had pain for at least 1 year, and it was commonly exacerbated by sitting and athletics. Patients reported clinically significant pain and functional limitation, which showed evidence of affecting general physical and mental health. It was not uncommon for patients to have undergone another, related surgery and nonoperative treatments, including intra-articular injection and/or physical therapy, before surgery. There was a high incidence of abnormal hip morphology suggestive of a cam lesion, but the incidence of arthritic changes on radiographs was relatively low. Labral tear was the most common diagnosis, and most often it was addressed with repair. Many patients underwent femoroplasty, acetabuloplasty, and chondroplasty in addition to labral repair.
According to patient-reported outcome measures administered before surgery, 40% to 65% of patients seeking hip preservation surgery reported functional deficits and pain—which falls within the range of results from other multicenter studies on the epidemiology of FAI.18,19 There was, however, a high amount of variability in individual scores on the functional and pain measures; some patients rated their functional ability very high. These findings were supported by the general health forms measuring global physical and mental health. Mean Physical Health and Mental Health scores on the 12-item Short Form Health Survey indicated that patients seeking hip preservation surgery thought their hip condition affected their general well-being. This finding is consistent with research on FAI,18 hip arthritis,20 and total hip arthroplasty.19Our results further showed that hip arthroscopists commonly prescribed alternative treatment measures ahead of surgery. Before elective surgery, 80% of patients received an intra-articular injection, underwent physical therapy, or both. This could suggest a high failure rate for patients who chose conservative treatment approaches for hip-related pathology. However, our study was limited in that it may have included patients who had improved significantly with conservative measures and decided to forgo arthroscopic hip surgery. Although conservative treatment often is recommended in an effort to potentially avoid surgery, there is a lack of research evaluating the efficacy of nonoperative care.21,22Analysis of diagnostic imaging and clinical examination findings revealed some unique characteristics of patients undergoing elective hip preservation surgery. MRI showed labral pathology in an overwhelming majority of these patients, but few had evidence of articular damage. Previous research has found a 67% rate of arthritic changes on diagnostic imaging, but our rate was much lower (17%).23 Radiograph evaluation confirmed the pattern: More than 90% of our patients had Tönnis grade 0 osteoarthritis. Tönnis grade 1 or 2 osteoarthritis is a predictor of acetabular cartilage degeneration,23 and long-term studies have related these osteoarthritic changes to poorer hip arthroscopy outcomes.24 Thus, the lower incidence of osteoarthritis in our study population may reflect current evidence-based practice and a contemporary approach to patient selection.
Most of our patients had isolated cam-type FAI as opposed to pincer-type FAI or a combination of cam and pincer—contrary to research findings that combination cam–pincer FAI is most prevalent.25,26 Our results are more consistent with more recent research findings of a higher incidence of isolated cam lesion, particularly in female patients, and combination cam–pincer in male patients.18,27,28 Similar distributions of surgical procedures and diagnoses exist between the present study and other multicenter evaluations of the epidemiologic characteristics of patients with hip pathology.18Our study had several limitations. First, the population consisted entirely of patients who sought evaluation by a hip arthroscopy specialist and underwent elective surgery. Therefore, the data cannot be applied to a more general orthopedic population or to patients who consult other medical specialists. Second, the population, which was 97% white and had small percentages of African-American, Latino, and Asian patients, lacked ethnic diversity. This finding is consistent with recent epidemiologic research in which ethnicity was identified as a factor in patterns of hip disease.13,29,30 Access to specialists, however, was likely affected by multiple other factors. Fourth, the validity and the reliability of the imaging modalities used have been questioned.31-33 There is controversy regarding ideal imaging modalities for assessment of articular cartilage damage31,32 and FAI. However, the modalities that we used to determine diagnoses in this study are well supported26 and represent common practice patterns.
Am J Orthop. 2017;46(1):35-41. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.