When to get married? When to quarantine? When to have a total knee replacement? A new study can’t help much with the first two, but as for the third, Hassan Ghomrawi, Ph.D., M.P.H., an associate professor of surgery at Northwestern University Feinberg School of Medicine in Chicago, has some guidance. His work, “Examining Timeliness of Total Knee Replacement Among Patients with Knee Osteoarthritis in the U.S.: Results from the OAI and MOST Longitudinal Cohorts,” appears in the January 13, 2020 edition of The Journal of Bone and Joint Surgery.
“We already knew that the timing of surgery for knee osteoarthritis (OA) patients was ‘off,’” states Dr. Ghomrawi. “Our team set out to quantify how many people were early or late and why.”
Using data from The Osteoarthritis Initiative and Multicenter
Osteoarthritis Study, the
researchers looked at patients who had or were at risk
for knee OA and were followed for up to eight years. 
Dr. Ghomrawi: “These are two well-established, NIH-funded cohorts that are similar in the way that data is collected. To determine who was early and who was late, we applied algorithms that are validated against outcomes meaning that if the algorithm says that surgery is appropriate then you are going to get significant improvement in pain relief and functional improvement from surgery at two years and if the algorithm says you’re not, then you will get little benefit.” The novelty, says Dr. Ghomrawi, is that because these patients with OA were closely followed for so long that they were able to determine which year they become appropriate for surgery.
“We classified patients into three categories: 1) timely, i.e., the person had total knee replacement (TKR) within two years after the procedure had become potentially appropriate, 2) potentially appropriate but did not undergo TKR (the knee had remained unreplaced for >2 years after the procedure had become potentially appropriate), and 3) premature (procedure was most likely inappropriate but had been performed).”
The researchers found the categories as follows: 290 knees were classified as “timely,” 2,833 knees were classified as “potentially appropriate but not replaced,” and 294 knees were considered to be “likely inappropriate” yet underwent total knee replacement and were classified as “premature.”
“Few other researchers are using these criteria, and the criteria have not made it to the clinic yet. Clinicians may feel threatened by the use of risk calculators deciding whether a patient has surgery or not. However, emerging studies from orthopedics and other fields show that these risk calculators predict outcomes more accurately than clinicians. So we see these algorithms as decision aids that would help clinicians and patients make more informed decisions.”
“We found that a full 26% of patients who had TKR had it early. Most of those were not obese. As for what motivations led to this decision, my sense is that some of these individuals are the sole breadwinners and cannot afford to lose function that may affect their earnings, but it could also be folks who want to continue to play their golf.”
“On the other hand, of those found to be appropriate for surgery, 90% chose not to undergo the procedure. This was big news to us because it suggests a huge unmet need for TKR!” said Ghomrawi. Although they don’t have details as to why, the researchers did find that African Americans were more likely to delay surgery. “It is not particularly surprising as many studies have pointed to these disparities, but we suspect there are other factors involved.”
So, why is timing of surgery important? “If someone undergoes surgery too early, he or she may experience little improvement in function and pain relief and are subjected to the risk of a major surgery. Also, to be considered is that if someone is young then they may require a revision down the line. If they delay surgery, the debilitation that results from knee OA is not insignificant. Not only do patients lose quality of life, but it affects cardiovascular health and sleep.”
Dr. Ghomrawi: “Moving forward, we are interested in understanding the factors that affect premature use and late use. These are likely those that fall within the category of social determinants of health. On the Upper East side of Manhattan or in Naperville, IL, you could start having pain on a Friday night and demand surgery on Monday morning. In other areas, people will wait, suggesting an effect of the environment on people’s decision to undergo surgery.”
Dr. Ghomrawi said that he himself has very minor knee pain. OSN wonders if or when Dr. Ghomrawi will have surgery.
Well, in this new world, who knows???