Clinical Trial: Functional Capacity After Computer Assisted Periacetabular Osteotomy in Patients With Hip Dysplasia

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Functional Capacity After Computer Assisted Periacetabular Osteotomy in Patients With Hip Dysplasia

Brief Summary:

Pathogenesis of hip dysplasia Hip dysplasia is multifactorial in origin influenced by genetic and intrauterine factors, such as mechanical (rump presentation and oligohydramnios) and hormonal factors1. To ease the passage through the birth canal, the hip joint is quite mobile perinatally. Postnatally, the laxity of the ligaments will subside and the femoral head will normally position itself deeply in the acetabulum2. The theory is that if the femoral head does not migrate sufficiently into the acetabulum, dysplasia may develop because the matrice to stimulate acetabular growth is not correctly positioned. Normally, at birth the femoral head sits deep in the acetabulum held by surface tension of the synovial liquid. The growth and the hemispherical morphology of acetabulum are dependent on the presence of a normally growing and correctly placed spherical femoral head that works as a convex matrice. If for some reason the normal development is disturbed pre- or postnatally, pathologic relations may develop between the femoral head and the acetabulum3, leading to hip dysplasia.

Purpose of this research project is to investigate if the correction of the acetabulum is accurately performed when the surgeon use navigation equipment during PAO.

Detailed Summary:

Morphological changes in hip dysplasia The dysplastic hip joint has a complex morphology characterised by a wide shallow acetabular cavity with an excessively oblique articulating roof. The acetabular cover of the femoral head is globally deficient4;5 and the acetabular rim is hypertrophied possibly due to excessive pull from the often hypertrophic labrum. Anteversion is normal5-7, but occasionally the acetabulum is retroverted8;9. The weight-bearing area between the acetabular roof and head is reduced and the articular cartilage is significantly thicker than normal10. Hip dysplasia is often associated with increased anteversion of the femoral neck5;11 and with valgus neck-shaft angle that results in a reduced abductor lever arm12. However the deformities vary from individual to individual and retroversion of the femoral neck has also been reported in hip dysplasia12. Patients with hip dysplasia are prone to developing osteoarthritis of the hip at a young age 13;14. The reasons for this are not fully understood, but an explanation could be that the reduced contact area between acetabulum and the femoral head as well as a reduced abductor lever arm increase the load per contact-area in the hip joint4. The increased load is a strain on the articular cartilage and believed to result in degeneration of cartilage and the subchondral bone and eventually osteoarthritis14-17. The purpose of periacetabular osteotomy (PAO) is to increase acetabular cover of the femoral head and thereby distribute pressures better over the available cartilage surface.

PAO followed by rehabilitation At PAO, the pubic bone is osteotomized and under fluoroscopic control, the ischial osteotomies and the posterior iliac osteotomy are performed. The acetabular fragment is repositioned to optimise coverage of the femoral head. The repositioning is very challenging and clearly the most demanding aspect of t
Sponsor: University of Aarhus

Current Primary Outcome: correction of acetabular fragment in 3D [ Time Frame: 4 months postop ]

Original Primary Outcome: Same as current

Current Secondary Outcome: functional capacity [ Time Frame: 1 year postop ]

Original Secondary Outcome: Same as current

Information By: University of Aarhus

Dates:
Date Received: July 9, 2013
Date Started: December 2013
Date Completion:
Last Updated: November 19, 2015
Last Verified: August 2013