Hip Resurfacing Advantages ...

Study: Surface replacement arthroplasty may offer advantages over THA

READ COMPLETE STUDY

Canadian investigators said hip resurfacing resulted in greater patient activity after 2 years.

By Robert Trace
1st on the web (September 19, 2007)
September 2007

SEOUL — Total hip arthroplasty is an established procedure with well-documented complication rates and clinical results, but surface replacement arthroplasty may offer additional clinical benefits to many patients, according to a group of Canadian researchers.

"We decided in 2003 to do a comparative study of hip resurfacing, or surface replacement arthroplasty (SRA), to the gold standard of total hip arthroplasty (THA), since we were not aware of any direct prospective studies out there comparing the two procedures," said Pascal-André Venditolli, MD, of the Maisonneuve-Rosemont Hospital in Quebec.

He and his colleagues randomly assigned 210 hips to receive uncemented metal-on-metal THA (103 hips) or a hybrid metal-on-metal SRA (107 hips). All surgeries were performed by three orthopedic surgeons, who used a posterior approach.

The researchers prospectively collected perioperative and postoperative data, and analyzed the clinical data for a minimum of 2 years.

Postop complications included three isolated traumatic dislocations and one recurrent dislocation in the THA group, which required acetabular cup revision. Two SRAs required revision for late head collapse. No postop femoral neck fractures occurred in the SRA group, he said.

There was one case of loosening at 6 months postop in the resurfacing group, which had shifted varus. There were also two cases of deep venous thrombosis in both patient groups, he said.

Although the investigators did not report a significant difference in surgical time between the two procedures, patients' length of stay in the hospital was significantly shorter for the SRA group compared to the THA patients — 5 days vs. 6.1 days for the THA group (P=.001).

"There was also a significant difference in return to work: 96% of the SRA patients returned to their previous work within 1 year vs. 83% in the THA group," Venditolli said.

Although patients in both groups demonstrated a high satisfaction rate and achieved similar WOMAC and Merle d'Aubigné functional scores, "SRA patients had better UCLA activity scores (7.1 vs. 6.3; P=.037) and returned to heavier activities (P=.035)" after 2 years, he said.

"This randomized study shows that SRA and THA present a similar complication rate, but distinctive complications," Venditolli said. "It also suggests that SRA results in better function and improved patient activity in comparison to THA.

"However, the effect of long-term fixation related to increased activity levels is unknown. Long-term follow-up is necessary to determine the survivorship of SRA over THA," he said.

For more information:

Vendittoli P-A, Lavigne M, Lusignan D, Roy A-G. A randomized study comparing surface replacement arthroplasty to total hip arthroplasty: 2-4 years follow-up. F028-2. Presented at the 15th Triennial Congress of the Asia Pacific Orthopaedic Association. Sept. 9-13, 2007. Seoul.

READ COMPLETE STUDY