Source: Chest  |  Posted 5 years ago

By Jill Stein

SAN DIEGO, CA -- February 16, 2007 -- A hip arthroplasty procedure that uses metal-on-metal resurfacing appears to result in good short- to mid-term follow-up among young, active adults, researchers reported here at the 2007 Annual Meeting of the American Academy of Orthopedic Surgeons (AAOS).

Harlan C. Amstutz, MD, founding director, Joint Replacement Institute, Orthopaedic Hospital, Los Angeles, California, presented the results achieved with the procedure in a cohort of 295 patients (350 hips) younger than 50 years of age.

At an average follow up of 5.5 years, University of California at Los Angeles hip scores had improved from 3.4 to 9.4 for pain, 6.0 to 9.6 for walking, 5.6 to 9.5 for function, and 4.5 to 7.6 for activity.

Hips with good bone quality, defined as cystic defects smaller than 1 cm, had a 5-year survivorship of 97.8%, Dr. Amstutz said in his presentation on February 14[^]th[].

To date there have been no cases of femoral component loosening when the femoral stems were cemented regardless of bone equality, he said.

Ten (2.8%) hips were revised for femoral aseptic loosening and 1 for femoral neck fracture.

When the investigators compared these results with results in 281 patients (336 hips) 50 years of age or older at the time of surgery who underwent with metal-on-metal resurfacing, there was no difference in prosthetic survivorship between the younger and older groups even after adjustment for Surface Arthroplasty Risk Index (SARI) score, Dr. Amstutz said.

The postoperative clinical scores improved in the younger and older groups compared with pre-operative values.

Overall, the results indicate that metal-on-metal resurfacing arthroplasty of the hip is producing encouraging results in a young active population, Dr. Amstutz said.

He added that younger patients are at increased risk of early failure with conventional stemmed total hip arthroplasty and modern-generation resurfacing total hip arthroplasty may be a prudent option for this population with respect to prosthetic survival and clinical results.

Finally, he emphasized that patient selection is important for optimizing outcomes and added that the best results were seen in young adults with good bone quality.

Also, because metal-on-metal total hip resurfacing devices have only been available for about 10 years, it is not yet known whether these favorable short- to mid-term results will hold up over the long term, he said.

[Presentation title: Hip Resurfacing for Patients Under 50 Years of Age. Abstract 124]