A recent study published in Arthritis and Rheumatism suggests that one in three total knee replacement operations may be unnecessary, leading authors to call for a more stringent patient selection criteria.
For their study, researchers conducted a five-year analysis of 205 patients who underwent a total knee anthroplasty (TKA) because they were classified as high risk for knee osteoarthritis. 60 percent of the patients were women, and the average age was 66.9 years old.
Using the Escobar system of knee arthroplasty classification that marks operations as appropriate, inconclusive or inappropriate on the basis of patient symptoms, functional status, extent of arthritis, age, mobility, stability and history of treatment, researchers were able to get a better understanding of the success of the surgery. After putting the data through the Escobar system, researchers found:
- 44% were appropriate
- 34.3% were inappropriate
- 21.7% were inconclusive.
Dr. Daniel Riddle, lead researcher of the study, said he hopes the findings help reduce the number of inappropriate and unsuccessful knee replacement surgeries.
“The goal was not to necessarily suggest that knee replacement surgery is done inappropriately in this country, rather, the intent was to characterize the extent of variation in the key characteristics of patients who eventually undergo a procedure. This has never been done in the US to this extent before,” said Dr. Riddle. “It is our hope that characterizing this extent of variation will aid policy makers, and particularly clinicians who are directly involved with these patients, to begin to consider if one can reduce the amount of variation.”
Dr. Jeffery Katz said he agreed with Dr. Riddle’s assertion that total knee replacement might not be the best course of action for patients with mild symptoms, “but before we accept that a third of TKRs performed in the US at present are inappropriate, we should think carefully about whether ‘appropriateness’ can be judged without considering the prevailing values that patients and the larger society attach to functional deterioration and preservation.”
Although total knee replacement is usually only pursued after nonsurgical options such as weight loss, medications and physical therapy have failed, researchers want to develop a more comprehensive assessment tool to ensure patients don’t undergo an inapprotiate knee replacement.
Dr. Silverman comments
This was a great study to do, especially considering that 10 percent of patients with total knee replacement surgery hurt afterwards for unknown reasons. Identifying patients who are more appropriate candidates for the procedure will hopefully cut down on this complication.
It is troubling that the number is so high, although it’s not too surprising considering people are so interested in walking without pain. This may lead them to pursue an unnecessary surgery. But the onus is also on the doctors. Some doctors may incorrectly believe the knee joint is the source of the pain when it’s a secondary pain. Only when secondary causes of the joint pain are identified by a full evaluation and are corrected is a total knee replacement appropriate. Patients need physical therapy, and again, the pain may not actually be starting in the knee. Identifying the true source of pain is key.
The hip and the muscles that extend from it are great masqueraders of knee pain. For example, an overly tight IT band can cause severe medial joint pain. Similarly, problems along the obturator nerve along the inside of the hip can cause medial knee pain. Any lower extremity problem that causes leg external rotation (twisting the foot out towards the side) can cause either anterior knee pain or medial knee pain.
Those particular problems can be addressed quickly with nonsurgical options. It is unfortunate that some patients don’t have their true symptoms recognized until after total knee replacement.
Related source: Medscape