Recommended follow-up visits after cemented THA may be unnecessary

British study findings suggest first evaluations at first postoperative year and 8 years may be enough.

VIENNA — A review of surgical records has shown that the recommended schedule for follow-up visits after cemented total hip arthroplasty could be safely changed to require fewer visits.

“We recommend that the follow-up of cemented total hip replacements occur through the first postoperative year and then they not be followed up until 8 years postoperation and then annually thereafter, assuming they remain asymptomatic,” Cronan Kerin, MRCS, said at the 10th EFORT Congress, here.

“The aim of our study was to find an evidence basis for follow-up of cemented primary total hip replacements, and to our knowledge, this is the only such study in the English-speaking literature,” he said.

“The British Orthopaedic Association guidelines suggests a follow-up by the operating surgeon within 8 weeks of surgery, and over the long term, they suggest that the minimum required follow-up include history, clinical evolution and AP and lateral radiographs at 1 and 5 years and every subsequent 5 years after the operation,” Kerin said.

Records review

The investigators identified all of the primary total hip replacements (THRs) performed from 1996 to 1997 at Oswestry, Shropshire, England. They used an electronic patient records system to review the files of each of those patients. Age, sex, site of the procedure, evidence of radiological loosening as well as time to revision surgery were recorded, Kerin said. The endpoints of the study were documented radiolucent lines around the implant or the time of revision surgery.

Those data indicated that, at that time, the majority of primary THRs were performed cemented. Only 4.5% were uncemented, he noted.

The data were then analyzed using a trademarked software package. The researchers used life table and Kaplan-Meier analyses.

Follow-up rates

“Historically at our institution, the follow-ups have been at 6 weeks, 3 months, 6 months, 1 year, 5 years and subsequent 5 years after that,” Kerin said. “One surgery varied by having one follow-up a year after the first year.”

Overall, they found 425 consecutive primary THRs during 1996 and 1997; 130 patients did not come back for the follow-up. These were implanted in 274 women and 151 men, who had an overall mean age of 65 years.

“Using radiological evidence of loosening as the endpoint, we found that there was a peak initially after surgery and a peak again at 8 years,” Kerin said.

The 10-year survival rate was 85.8%. “Using revision surgery as the endpoint, we found that there was, again, an initial peak and a peak at 8 years after surgery,” he said. In this group, there was a 10-year survival rate of 91.5%.

“Our conclusion: Once patients have made it through the first postoperative year, they do not need to be followed up again until 8 years, assuming they remain asymptomatic,” Kerin said.

Reference:
Kerin C, Cheung G, Cool P, Graham N. Do we need to follow up primary total hip replacements? Paper F489. Presented at the 10th EFORT Congress. June 3-6, 2009. Vienna.