[Arthrodesis of the hip and its conversion].

Arthrodesis of the hip used to be an important means of treating painful and damaged hips. Increasing experiences in total hip replacement have led to restrictive indications for arthrodesis and to more and more total hip arthroplasty. Hip arthrodesis has limited indications today. It remains the treatment of choice in deteriorated, painful hip joints, especially in the case of contraindications and severe muscular deficits. The best position of the fused hip is 10 to 25 degrees flexion, 0 to 15 degrees external rotation, 0 to 10 degrees abduction or 0 to 6 degrees adduction. The aim of the operation is a stable osteosynthesis which allows early mobilisation of the patient. Disturbances in walking patterns, mechanical overloading of neighbouring joints, such as the lumbar spine, ipsilateral knee or contralateral hip, often support a conversion from arthrodesis to total hip arthroplasty. The aim of the primary operation, therefore, is the preservation of the stabilizing pelvitrochanteric muscles and their insertions.