Cumulative Hip Contact Stress Predicts Osteoarthritis in DDH

Abstract

Hip stresses are generally believed to influence whether a hip develops osteoarthritis (OA); similarly, various osteotomies have been proposed to reduce contact stresses and the risk of OA. We asked whether elevated hip contact stress predicted osteoarthritis in initially asymptomatic human hips. We identified 58 nonoperatively treated nonsubluxated hips with developmental dysplasia (DDH) without symptoms at skeletal maturity; the control group included 48 adult hips without hip disease. The minimum followup was 20 years (mean, 29 years; range, 20-41 years). Peak contact stress was computed with the HIPSTRESS method using anteroposterior pelvic radiographs at skeletal maturity. The cumulative contact stress was determined by multiplying the peak contact stress by age at followup. We compared WOMAC scores and radiographic indices of OA. Dysplastic hips had higher mean peak contact and higher mean cumulative contact stress than normal hips. Mean WOMAC scores and percentage of asymptomatic hips in the study group (mean age 51 years) were similar to those in the control group (mean age 68 years). After adjusting for gender and age, the cumulative contact stress, Wiberg center-edge angle, body mass index, but not the peak contact stress, independently predicted the final WOMAC score in dysplastic hips but not in normal hips. Cumulative contact stress predicted early hip OA better than the Wiberg center-edge angle.

Patient-specific analysis of cartilage and labrum mechanics in human hips with acetabular dysplasia

“…Previous mathematical and FE studies have assumed spherical, concentric geometry [14, 42, 43], and have mostly omitted the acetabular labrum [42, 43]. By simple description of stress as force divided by area, it would follow that any global reduction in coverage would cause an increase in cartilage contact stress for idealized hip geometry.…”

Acetabular Tilt Correlates with Acetabular Version and Coverage in Hip Dysplasia

“…Patients with DDH present with morphologic abnormalities, such as insufficient acetabular coverage of the femoral head, a shallow acetabular concavity, and a maloriented acetabulum [6,14,26]. These deformities lead to abnormal stress distributions on the articular weightbearing area, elevated joint contact pressures, and shearing stresses on the acetabular rim complex [10,12,24]. Thus, these patients often have labral tearing and cartilage degeneration develop at an early age, resulting in premature hip osteoarthritis [18,26,30,37,38].…”

Role of Biomechanical Parameters in Hip Osteoarthritis and Avascular Necrosis of Femoral Head

“…Biomechanical evaluation of hip joint after Salter innominate osteotomy: a long-term follow-up study. Arch Orthop Trauma Surg, 121, (511-516), ISSN 0936-8051 Zupanc, O., Križančič, M., Daniel, M., Mavčič, B., Antolič, V., Iglič, A., Kralj-Iglič, V., (2008).…”

“…In particular, the results indicated that long lasting elevated contact stress is connected to degeneration of the hip articular cartilage and development of hip osteoarthritis (Dolinar (2003); Kralj (2005); 2008); Pompe (2003); Rečnik (2007;2009a;). …”

“…We took part in development of a mathematical model for determination of the contact hip stress distribution (Iglič (1993b); ) and in population studies which were performed to validate the model. Different diseases and disorders of the hip were considered by this model: hip dysplasia 2008); Pompe (2003;), slipped epiphysis of the femoral head (Zupanc (2008)), avascular necrosis of the femoral head (Daniel (2006); Dolinar (2003)), postoperative changes in hip geometry (Herman (2002); Kralj (2005); Vengust (2001)) and osteoarthritis of the hip (Rečnik (2007;2009a;). The method HIPSTRESS was put forward consisting of mathematical model for resultant hip force (Iglič (1990;1993a)), mathematical model for contact hip stress (Iglič (1993b); ) and the corresponding software.…”