There are some wonderful new ways to treat osteoarthritis in young, active adults. We’re talking adults as young as in their 30s up to early 60s. Up until recently, only older adults were considered for a knee joint replacement. The acceptable age for that has gone down.
Then they came out with a half-knee joint replacement called a unicompartmental knee arthroplasty (UKA). That works well for people with more arthritis on one side of the knee than on the other. Most often, it’s the medial side of the joint (side closest to the other knee) that wears down and develops painful knee arthritis. So the surgeon just replaces that side of the joint with an implant.
But what about patients who are too young or too early in the course of their disease (osteoarthritis) to qualify for a unicompartmental knee arthroplasty (UKA)? What can they do to stay active, participate in sports, or keep up in their jobs when their knee pain limits them? In this report, the results of a high tibial osteotomy (HTO) for this problem are presented.
About 80 patients with medial (inside edge) unicompartmental (one side only) osteoarthritis were treated with this surgical procedure. The patients selected were too young for a unicompartmental knee arthroplasty (UKA). Average age was around 41 years old. Sports and recreational activities were limited by their pain. Conservative (nonoperative) care hadn’t helped. That left the high tibial osteotomy (HTO) as a potential treatment choice.
The patients were examined first arthroscopically. If there was too much damage to the joint or too much of the lateral meniscus (cartilage) missing, then they were not considered a good candidate for the high tibial osteotomy (HTO). The same was true if there wasn’t enough knee flexion or too much knee extension. Other reasons patients might not qualify for this procedure included joint infection, instability (ligament damage), or active joint inflammation from arthritis.
For those people who qualified for the HTO, a wedge-shaped piece of bone was removed from the upper part of the tibia (lower leg bone that forms the bottom half of the knee joint). The remaining two edges of the bone were lined up at in a position of 62 per cent valgus (angled slightly inward). The medial collateral ligament (MCL) along the inside of the knee was partially cut. This step was taken to decrease the amount of pressure placed on the medial side of the knee.
The remaining bone was held together with a metal plate and multiple screws until healing took place. The hole made by removing the pie-shaped piece of bone was not filled in with bone graft. When the body filled in the gap and bone remodeling was complete, then the hardware was removed. This took place around one-year after the initial surgery.
Patients were asked about results through a mailed questionnaire. They answered question about pain, motion, and function. They listed how much pain medication they used during sports activity. And they completed two survey tools to measure activity: the Tegner Activity Scale and the Activity Rating Scale.
Before surgery, the patients reported a major decline in their ability to participate in sports or other recreational activities. Some were unable to resume their desired level of activity after the HTO. But after the operation, they were able to remain as active as they had been just before surgery. Many traded activities. Those who were engaged in jogging or running started walking instead.
Not everyone was satisfied with the results of the procedure. Only 35 per cent (one in three patients) said they were extremely satisfied. About 25 per cent (one in four) said either not satisfied or only partly satisfied with the results. Those few patients (4.5 per cent of the total) who were involved in competitive sports before surgery, did not return to high-level activity or events postoperatively.
Age did not seem to make a difference in how often or how long patients engaged in an activity or sport. Older adults did seem to have greater improvement in function before and after surgery. This group’s pre-operative condition was much more limited than in younger adults so the difference before and after seemed greater.
The authors don’t know exactly why the patients’ activity level was so much less after surgery. They suggested it might be because patients were protecting the knee from further damage. They may have been worried that the repair might not hold up — or that they would end up needing a joint replacement sooner than later.
The benefit of this study was to find out how often patients return to sporting activities after high tibial osteotomy (HTO). Could this be a good middle step between conservative care and a unicompartmental knee replacement? Could it help active, younger adults with the start of painful knee arthritis to stay in the game?
Other studies of HTO have shown a clear shift away from high-impact activities toward lower-impact sports. This wasn’t the case in this study. Participation in most of the top 10 activities remained the same.
As mentioned, there was some modification of activities from running to walking. Some patients had more than the one HTO procedure. That didn’t seem to affect outcomes either. This information will help surgeons know they can make other necessary repairs without fear of affecting the results.
Overall, it looks like the HTO procedure has good results and some excellent advantages. It’s not necessary to cut through the tibialis anterior muscle when doing the procedure like osteotomies done a little lower on the tibia or osteotomies done on the opposite side. There’s less risk of damage to the peroneal nerve. There are fewer problems with shortening of the leg. And best of all, it can improve symptoms and delay total joint replacement by preventing disease progression.