John C. Clohisy, MD, FAAOS


Published 3/8/2024

Kappa Delta Elizabeth Winston Lanier Award Presented to the ANCHOR Group for Improving Quality of Care for Young Patients with Pre-Arthritic Hip Conditions

The 2024 Kappa Delta Elizabeth Winston Lanier Award was presented to the Academic Network of Conservative Hip Outcomes Research (ANCHOR) group for 20 years of research to improve the quality of care for adolescent and young adult patients with the three most common pre-arthritic hip conditions: femoroacetabular impingement (FAI), developmental dysplasia of the hip (DDH), and residual Legg-Calve-Perthes disease. Their research has helped the orthopaedic community better understand the basic pathophysiology of hip osteoarthritis (OA), disease natural history, diagnosis, surgical treatment, and predictors of treatment outcomes for young patients who often live with hip dysfunction for years or even decades with eventual progression to advanced OA.

“In the early 2000s, the orthopaedic community lacked an understanding of pre-arthritic hip disease diagnoses and treatments. Variable patient age at presentation, lack of generalizable surgical treatments, and limited clinical outcomes reporting for hip-preservation procedures were major challenges,” said lead researcher John C. Clohisy, MD, FAAOS, Daniel C. and Betty B. Viehmann Distinguished Professor of Orthopaedic Surgery at Washington University in St. Louis.

The ANCHOR group, coordinated from Washington University, initially enrolled two cohorts—FAI-1 and PAO-1 (periacetabular osteotomy), totaling 3,168 surgical cases—to detail population characteristics of FAI and DDH patients and to investigate the safety and efficacy of surgical treatments. Data collection of clinical presentation, diagnosis, patient-reported outcome measures (PROMs), radiographic imaging, surgical procedure details, and intraoperative disease classification set the foundation for subsequent investigations. This dataset enabled the group to examine several key performance indicators to provide quantitative measurement of improved patient outcomes.

Timely diagnosis
The ANCHOR group performed a series of foundational studies to describe the clinical presentation and epidemiology of patients with FAI, DDH, and labral tears. Findings of the studies included:

  • There was a predominance of DDH in young, active females, who often presented with significant hip dysfunction and symptoms, including groin or lateral hip pain. Clinical presentation was accelerated with high activity levels and more severe deformity.
  • Females with FAI had greater symptomatology and milder morphologic abnormalities, whereas males had higher activity levels, larger morphologic abnormalities, and more extensive intra-articular disease. Both groups presented with activity-related groin pain and tended to have restricted hip range of motion and progressive symptoms over time.

Patient satisfaction
The ANCHOR group measured patient-reported satisfaction with standardized methodology to provide feedback on the patient experience associated with surgery for FAI. The findings included:

  • FAI patients self-reported high overall satisfaction rates (>91 percent) and low rates of dissatisfaction (>9 percent). Long-term mean 10-year follow-up of the FAI-1 cohort was recently completed (unpublished data) and demonstrated maintenance of these high satisfaction rates (91 percent).
  • Most patients studied who underwent PAO surgery demonstrated marked clinical improvement and returned to sport, and only a small percentage had activity limitations from surgical hip symptoms (<11 percent). overall patient satisfaction in pao patients was also consistently more than 90 percent.>

Early skepticism among the orthopaedic community related to the diagnosis of FAI, its association with hip OA, indications for surgery, and efficacy of surgery required critical investigation of these new concepts. ANCHOR’s findings included:

  • Preoperative PROM score was a strong, highly significant predictor of all outcomes. More recent analyses have determined that competitive athletes had superior outcomes and lower failure rates compared with non-athletes (after controlling for important covariates). For FAI surgery, a lower risk of clinical failure was associated with participation in competitive athletics (P = 0.01) and male sex (P <0.001).>
  • Longer chronicity of preoperative symptoms, patients aged >40 years requiring acetabular microfracture, and revision surgery were independently associated with inferior clinical outcomes. Subgroup analysis of adolescent patients identified females, mild cam FAI deformities, and lack of sports participation to be associated with higher rates of treatment failure.

“Over the past 20 years, access to quality care for young patients with pre-arthritic hip disease has markedly improved” said Dr. Clohisy. “We now have surgeons and healthcare teams who can deliver a comprehensive approach to manage the full spectrum of pre-arthritic hip disease. While we’ve made great strides, we’re continuing to improve by better defining and diagnosing the conditions, determining the best indications for surgery, and optimizing our surgical techniques.”

The ANCHOR group will be honored at the Your Academy event Wednesday morning.


  1. Kotlarz H, Gunnarsson CL, Fang H, et al: Insurer and out-of-pocket costs of osteoarthritis in the US: evidence from national survey data. Arthritis Rheum 209;60(12):3546-53.