Comparison of cemented ceramic and metal-polyethylene coupling hip prostheses in ankylosing spondylitis

Two groups of patients suffering from ankylosing spondylitis were treated by total hip arthroplasty. Twenty-one patients (37 hips) were treated with cemented metal-polyethylene prosthesis, whereas 18 patients (36 hips) had cemented ceramic coupling implants. The two groups had similar preoperative clinical data. The average follow-up period was seven to eight years for both. Each patient was graded clinically (pain, function, range of motion, deformities) and roentgenographically (radiolucent lines, etc.). Patients with metal-polyethylene implants showed important modifications of the bone around the implant. Clinical and roentgenographic results were relatively good in patients with ceramic implants. The results underline the importance of the friction coupling of the implant.