Acetabular Undercoverage, Overcoverage Associated With Hip OA

It’s not often that a natural history museum takes part in advancing our knowledge of hip conditions. But researchers from Case Western Reserve University in Cleveland have done just that. They “mined” the Hamann-Todd Museum at the Cleveland Museum of Natural History in order to help improve treatment of hip osteoarthritis.

Their work, “Decreased and increased relative acetabular volume predict the development of osteoarthritis of the hip-an osteological review of 1090 hips,” appeared in the April 6, 2017 edition of The Bone & Joint Journal.

Douglas S. Weinberg, M.D. is an orthopedic resident at Case Western and a co-author on the study. He told OTW, “We have been interested in the relationship between FAI [femoral acetabular impingement] parameters, developmental dysplasia of the hip, and arthritis. We felt that using the Hamann-Todd osteological collection would be a good chance to look at a truly randomly sampled population in a unique way.”

“Access to this collection allowed us to measure anatomic parameters that are not otherwise obtainable clinically. To our knowledge, this is one of the first reports on acetabular and femoral head volume in the literature. Doing experiments such as this at the Hamann-Todd Museum allows us to analyze things that cannot be seen on X-ray or MRI. Developing a better understand of acetabular volume and hip joint coverage can have important implications in the treatment of hip dysplasia and femoroacetabular impingement.”

The authors wrote, “A total of 545 cadaveric skeletons (1090 hips) from the Hamann-Todd osteological collection were obtained. Femoral head volume (FHV), acetabular volume (AV), the FHV/AV ratio, acetabular version, alpha angle and anterior femoral neck offset (AFNO) were measured. A validated grading system was used to quantify OA of the hip as minimal, moderate, or severe…”

“Acetabular undercoverage and overcoverage were independent predictors of increased OA of the hip. The alpha angle and AFNO had modest effects, supporting the hypothesis that bony abnormalities both in acetabular dysplasia and FAI are associated with severe OA.”

Dr. Weinberg told OTW, “The most important results are that both acetabular undercoverage and to a lesser extent, overcoverage, were associated with hip osteoarthritis. This data suggests that FAI may have some modest effects on the development of hip osteoarthritis.”