Optimal results from uncemented total hip arthroplasty (THA) requires the prosthesis to obtain initial stability, restoration of biomechanics, bone contact along the ingrowth surface and uniform stress transfer to the proximal femur. Anatomic variation within the population makes this difficult to reproduce in every patient. To achieve optimal fit and fill of the proximal femur, options are reshaping the canal or creating an implant which precisely fits the patient's anatomy. The former increases bone loss and risks weakening the supporting bone, creating areas of stress concentration or shielding. Computer assisted design-computer assisted manufacture (CAD-CAM) femoral components were designed to overcome these issues. We present the long term results of CAD-CAM femoral components used in primary THA. This was a prospective study looking at a consecutive, single surgeon series of THA's. Patients were reviewed pre operatively then at 6 weeks, 3 and 12 months post operatively and then yearly. Clinical as well as radiological review was performed at each visit and Harris Hip Score (HHS), Oxford Hip Score (OHS) and Western Ontario McMaster's (WOMAC) scores were calculated. Kaplan-Meier survival analysis was performed.Introduction
Methods
The aim of this study was to evaluate the survival of a collarless, straight, hydroxyapatite-coated femoral stem in total hip arthroplasty (THA) at a minimum follow-up of 20 years. We reviewed the results of 165 THAs using the Omnifit HA system in 138 patients, performed between August 1993 and December 1999. The mean age of the patients at the time of surgery was 46 years (20 to 77). Avascular necrosis was the most common indication for THA, followed by ankylosing spondylitis and primary osteoarthritis. The mean follow-up was 22 years (20 to 31). At 20 and 25 years, 113 THAs in 91 patients and 63 THAs in 55 patients were available for review, respectively, while others died or were lost to follow-up. Kaplan-Meier analysis was performed to evaluate the survival of the stem. Radiographs were reviewed regularly, and the stability of the stem was evaluated using the Engh classification.Aims
Methods
