Excessive anteversion or retroversion can lead to dislocation. Femoral component position should be in 10-15° of anteversion. The acetabular component should be positioned at 20° of anteversion with an inclination of 45°. A hip positioned in varus can cause increased loosening and stem failure and can also lead to dislocation. Excessive valgus creates strain on the knee, can lengthen the leg, and can lead to superior dislocation with adduction of the leg. The overall position of the prosthetic hip replacement should ideally be in a mild degree of valgus, but should not exceed 140°. Multiple patient and surgical factors can alter the ideal position of the components. Stability of the prosthetic joint is the primary goal in choosing the position of implanted prosthesis. Attached to the femoral component is the neck and head which in most prostheses can be altered in size to create a stable joint.Īcetabular component: main variations in acetabular component on radiograph are related to fixation method and position. They can be described by length, taper, and presence of a collar. Metal-on-polyethylene (metal head with a polyethylene acetabular liner)Ĭeramic-on-ceramic (ceramic head with a ceramic acetabular liner)įemoral component or stem: this refers to the prosthesis which is implanted into the femur. Metal-on-metal (metal head and a metal acetabular component) These will give different appearance on radiograph depending on the configuration. The femoral head and the acetabular liner can be used in different combinations. Prosthesis designīearing surfaces are the surfaces which articulate in the prosthetic joint. A capsulotomy is then performed and the hip dislocated. This will uncover the short external rotators, which are dissected off the femur and retracted back over the sciatic nerve to protect the nerve throughout the operation. Dissection includes splitting fascia lata and gluteus maximus in line with its fibers. Skin incision is made 10-15 cm centered on the posterior aspect of the greater trochanter. Most common surgical approach for total hip arthroplasty is a posterior approach to the hip. IndicationsĬan be considered in a case by case basis in neck of femur fracture (displaced intracapsular) in active and healthy patients It is a commonly performed procedure usually with very good results and return to function. Total hip arthroplasty (THA), also known as total hip replacement (THR), is an orthopedic procedure that involves the surgical excision of the femoral head and cartilage of the acetabulum and replacement of the joint with articulating femoral and acetabular components.
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