Study: Surface replacement arthroplasty may offer advantages over THA
Canadian investigators said hip resurfacing resulted in greater patient activity
after 2 years.
By Robert Trace
1st on the web (September 19, 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
"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
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
"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.