03.19.12

Knee Replacement Data Scarce for Long-Term Safety, Effectiveness

Posted in Extremities at 1:40 PM by Dr. Greathouse

From Medscape Medical News

Not my area of expertise to be sure, but, I see my share of knee problems. Not to mention I have knee problems too. I know of patients I treat that still have knee pain after total knee replacement. I know that low back surgery outcomes are poor, but they continue and cost has continued to rise, but back pain prevails. At any rate, more food for thought and more reason perhaps, to exhaust conservative care before the big move to surgery. If you really need it, thank goodness it’s available! Be kind to your spine (and knees)!

Knee Replacement Data Scarce for Long-Term Safety, Effectiveness

March 5, 2012 — Knee replacement surgery is a success story of modern medicine, yet not enough is known about patient outcomes or the effectiveness of various implants, and consensus is lacking about the precise indications for the procedure, according to a study published online March 6 in the Lancet.

The authors, based in the United Kingdom, Sweden, and Australia, write that surgeons need improved decision-making as more and more possible candidates for new knees fall are younger than 55 years — a group that has a higher rate of revision or follow-up surgery. On another problematic note, some patients undergo the operation despite having good functional ability and only mild pain beforehand.

The article, based on a literature review going back to 1970, is the second in less than a week raising doubts about the evidence on orthopaedic joint implant safety and effectiveness. On February 28, the British Medical Journal published an article charging that hundreds of thousands of patients with metal-on-metal hip replacements were kept in the dark about possible exposure to toxic substances.

Andrew Carr, FRCS FmedSci, lead author of the Lancet article, and coauthors write that the number of total knee replacements (TKRs) in the United States increased from 31.2 per 100,000 person-years in the period from 1971 to 1976 to 220.9 per 100,000 person-years in 2008, for a total that year of more than 650,000 procedures. The authors predict that the demand for knee replacement will continue to grow in developed countries, in light of aging populations and rising obesity rates, which both portend higher rates of osteoarthritis, the main clinical indication for the operation.

Although more and more people are getting new hardware for their knees, fuzzy thinking prevails as to who really needs it.

“No clear consensus exists within the surgical community about exact indications, particularly severity of preoperative symptoms, obesity, and age,” Dr. Carr and coauthors write. They point to a task force organized by the Osteoarthritis Research Society International and a rheumatology organization that found that “pain, function, and radiographic severity are not associated with a surgeon’s recommendation for knee replacement.