New knees are not just for older patients. News Medical notes that the procedure is also used for younger patients with juvenile idiopathic arthritis (JIA) whose joints have been severely damaged by the disease. An international, multi-center study led by researchers at Hospital for Special Surgery (HSS) found that total knee replacements in younger patients with juvenile arthritis last at least 10 years in 92% of cases. More than 75% of the implants lasted 20 years or more.
“The surgery in this patient population, although performed by only a small number of highly specialized orthopedic surgeons nationwide, is life-changing for JIA patients, ” said Mark P. Figgie, M.D., senior author of the study and chief of the Surgical Arthritis Service at HSS. “Joint replacement can free patients—many of them adolescents—from a life of unrelenting pain. It can enable those in a wheel chair to walk again, giving many a new lease on life.” The investigators presented their study titled “Total Knee Arthroplasty in Patients with Juvenile Idiopathic Arthritis: A Multi-Center Study, ” at the annual meeting of the American Academy of Orthopaedic Surgeons (AAOS) in Chicago.
Figgie and colleagues compiled results from JIA patients who had total knee replacements by experienced orthopedic surgeons at five hospitals between 1979 and 2011. They identified a total of 217 patients with 335 knee replacements. They included in the survey data on revision surgery, walking tolerance, ability to go up and down stairs and the use of walking aids.
The average age at surgery was 28.1 ± 9.1 years with a mean follow up of 12.6 ± 6.9 years (range 2 to 33 years). Eleven patients (who had 14 knee replacements) had died, one bilateral TKR (total knee replacement) patient declined to participate and 21 patients (who had 30 knee replacements) remain to be contacted.
News Medical reported that the 10-year Kaplan Meier implant survival rate was 92.2%, and the 20-year survival was 75.5%. Of the assessed cases, walking tolerance was unlimited in 49% of patients. Another 22% of patients could walk 5 to 10 blocks, and 27% of patients could walk less than 5 blocks at latest follow up. Eighty-nine percent could manage stairs, and another 59% depended on railings. Slightly over 11% of knee replacement patients used a cane, 6.7% used crutches; and 11.7% used a wheel chair. At latest follow up, 29 of 335 knee replacements (8.7%) had required revision.
While the implants lasted at least 10 years in 92% of JIA patients, the data show that total knee replacements last slightly longer in elderly patients with osteoarthritis, said Figgie. “This is not really surprising, as the longevity of the implant may be affected by the JIA patient’s poor bone quality, severe joint deformities and contractures, and the immunosuppressive medications used to treat their disease.”
