Sports participation doesn't affect TKA durability

Total knee arthroplasty (TKA) patients may be able to participate in high-impact sports without increasing risk of early implant failure, according to the results of a new study. According to the authors of “Does Participation in Non-recommended Sports Impact Total Knee Arthroplasty Durability?” patients who participated in activities discouraged by the Knee Society (KS) had better clinical scores than patients in the control group.

The Knee Society recommends TKA patients avoid activities that cause high stress loads on the implant and may increase the risk of early failure. Such activities include high-impact aerobics, football, soccer, baseball, basketball, jogging, and power lifting, among others.

“Recent studies have shown that as many as one in six total knee replacement patients participate in non-recommended activities,” said study author Sebastian Parratte, MD, PhD. “This study offers them some reassurance.”

Researchers evaluated outcomes of 218 patients between the ages of 18 and 90 who underwent primary TKA at the Mayo Clinic and reported performing heavy manual labor or practicing a non-recommended sport following surgery. The “sport group” was matched by age, gender, and body mass index to a control group of 317 patients. Patients in the control group underwent the same procedure using an identical implant, but they followed recommended activity guidelines.

Clinical and radiologic results were measured using KS scores and implant survivorship was evaluated using multivariate analysis according to the Cox model.

At an average follow-up of 7.5 years after surgery, the study showed the following results:

  • No statistically significant radiological differences and no statistically significant differences in implant durability could be demonstrated between the sport group and the control group.
  • The sport group showed slightly higher KS knee and function scores compared to the control group, but this was not statistically significant.
  • The control group had a 20 per­cent higher revision rate for mechanical failure (loosening, wear, or fracture).
  • After accounting for all variables, including comorbidities, the sport group had a 10 percent higher risk of mechanical failure.

These results surprised Dr. Parratte and his team. “We hypothesized that high-impact activities would not increase the risk of implant failure, but we did not foresee that such activities might actually improve clinical results,” he said. “It is clear that more research is necessary to evaluate the short and long-term effect of high-impact activities on the durability and function of modern TKA implants.”

He added that, although the industry is not ready or able at this point to revise its recommendations, that possibility may exist in the not-too-distant future. In the meantime, he noted that surgeons and patients should continue to follow all industry recommendations relating to recovery following joint replacement surgery.

Co-authors for Scientific Paper 507 include Diane L. Dham, MD; Michael J. Stuart, MD; Mark W. Pagnano, MD; and Daniel J. Berry, MD. Dr. Parratte reports no conflicts.