Comparison of Hip Resurfacing and Cementless Metal-on-metal Total Hip Arthroplasty

Hip Osteoarthritis Clinical Trial

Official title: Comparison of Hip Resurfacing and Cementless Metal-on-metal Total Hip Arthroplasty - Prospective Randomized Clinival Trial

Status Completed

Clinical Trial Summary

To compare clinical, functional and radiological outcome after hip resurfacing and cementless metal-on-metal total hip arthroplasty.

Clinical Trial Description

While many problems associated with endoprosthetic surgery have been solved, there are still some open questions: In hip replacement one of the most controversial issues is the role and the indications for "resurfacing" (Schmalzried 2005, Hungerford 2005).

Resurfacing In traditional hip replacement, the head of the femur is replaced with a metal head secured to a stem in the femoral canal. In hip resurfacing, the neck of the femur is not cut, and instead the head of the femur is capped with a hemispherical metal ball articulated with an acetabular cup. The concept of resurfacing was developed as early as the 1970s, but it was abandoned due to unsatisfactory results. The procedure started to spark new interest in the 1990s as the results improved due to improvements in the articulation surfaces and fixation techniques (Amstutz 1998), and it has become considerably more common in the 2000s. In Australia, for example, resurfacing procedures accounted for 9% of all hip replacement operations carried out as a consequence of primary osteoarthritis, and their use has increased 17-fold in the 2000s (Australian Orthopedic Association National Joint Replacement Registry).

The partly assumed benefits of hip resurfacing include less bone resection in connection with the procedure, easiness of reoperation (a "conventional" replacement is carried out if reoperation is necessary), smaller risk of dislocation due to the larger head, and more physiological flexibility of the femur as the neck of the femur is not replaced with an inflexible metal stem. The short-term and mid-term results of modern resurfacing procedures presented in the reports of the developer clinics have been encouraging (Daniel 2004, Beaule 2004), but long-term results are lacking. Resurfacing procedures are technically more challenging and have given rise to complications that are not associated with conventional hip replacement, such as fractures of the femoral neck (Shimmin 2005). On the other hand, the socket and the diameter of the ball used in resurfacing procedures and conventional hip replacements are similar, and excellent results have been reached with modern conventional cementless stems (Eskelinen 2005). There are no published studies comparing modern resurfacing prostheses to solutions involving cementless stems with a large head and metal-on-metal articulation surfaces. ;

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Hip Osteoarthritis
• Osteoarthritis
• Osteoarthritis, Hip

• NCT number: NCT00570167
• Study type: Interventional
• Source: Helsinki University
• Status: Completed
• Phase: Phase 4
• Start date: November 2006