Should Younger Patients Ever Have Knee Replacement Surgery?

Christin L. Melton, ELS

Disclosures

April 29, 2015

In This Article

The Treatment of Choice for Younger Patients

Jack M. Bert, MD, an orthopedic surgeon at Minnesota Bone & Joint Specialists in Woodbury, Minnesota, has an important message for his colleagues: Always choose a high tibial osteotomy (HTO) over a knee replacement procedure for younger patients who have unicompartmental articular cartilage damage. He made his case in a presentation at Orthopedics Today Hawaii 2015 and elaborates on this perspective in an interview with Medscape.

"Osteotomy, particularly when combined with a cartilage resurfacing procedure, may prevent some patients from ever requiring a knee replacement. It will definitely delay the need for a total knee replacement for many years and hopefully salvage the joint long enough for technology to catch up," Dr Bert says.

Although HTO used to be common practice in the United States,[1] the annual growth rate in HTO declined 3.9% between 2007 and 2011.[2] "Meanwhile, there has been an upsurge in unilateral knee arthroplasty (UKA) for patients in their 30s and 40s, which is absolutely the wrong thing to do," he says.

Dr Bert says he typically reserves joint replacement procedures for "older patients who are less active and may never need to have their implant revised." Few high-quality randomized, controlled trials have directly compared outcomes with UKA vs HTO for unicompartmental osteoarthritis of the knee, but literature reviews suggest that the procedures have similar rates of success and complications.[3,4,5]

One reason Dr Bert prefers HTO to UKA or total knee arthroplasty (TKA) for younger patients is that the parts implanted during a UKA or TKA have a much shorter life expectancy than the patient. "The average knee implant lasts 10-12 years. Many patients today live into their early 80s, so when you perform a knee replacement on someone in their 40s, that person potentially will require two or three additional revision knee replacements in their lifetime," says Dr Bert. He warns that the risk for a failed implant increases with each successive TKA.

Another advantage of HTO is that it allows active patients to resume high-impact activities—such as running, jumping, and tennis—which are discouraged after UKA or TKA because they accelerate the failure of the implant.[6,7]

Dr Bert believes that younger patients are increasingly opting for UKA instead of osteotomy because recovery is typically faster after UKA.

"It is tough to convince patients to have an osteotomy when you have to tell them they will be on crutches anywhere from 6-12 weeks, depending on the type of osteotomy you do," says Dr Bert. In contrast, people can resume full weight-bearing on the knee after a UKA or TKA and are typically able to walk unassisted within 4 weeks of surgery.[8]

"As patients approach 60 years of age, a joint replacement procedure makes more sense because it provides immediate pain relief without a long recovery period," Dr Bert says.

Two Main Goals, and Two Main Techniques to Achieve Them

The primary goals of HTO are to slow the progression of posttraumatic osteoarthritis and to correct malalignment.[9,10] Dr Bert says correcting alignment is critical for a successful outcome after an articular cartilage resurfacing procedure. For example, if a patient undergoes meniscectomy and develops arthritis that causes the joint space to collapse, "performing cartilage resurfacing or marrow stimulation without correcting the patient's malalignment leaves the repair tissue overloaded and causes the cartilage resurfacing procedure to fail."

Clinical trials have shown that HTO improves pain and function in patients with medial compartmental knee osteoarthritis.[3] Whether HTO obviates the need for knee replacement later is less clear.

A 2014 Cochrane review of 21 controlled clinical trials of HTO reported that follow-up in most of the trials was too short to estimate the rate of failure after HTO.[3] A literature review of trials and observational studies that reported long-term outcomes after HTO for knee osteoarthritis found varying rates of survival (ie, no subsequent knee replacement).[11] Survival rates ranged from 75% to 94% at 5 years, 51%-98% at 10 years, 39%-90% at 15 years, and 30%-85% at 20 years, suggest that survival worsens over time.[11] Some studies indicate that the type of hardware used and patient selection independently predict the risk for failure after HTO.[3,5]

The two main HTO techniques used today are opening wedge and closing wedge. Dr Bert says the primary advantage of a closing-wedge HTO is that it allows a faster return to weight-bearing. For instance, "If you do a closing-wedge osteotomy, patients can be walking in 3-4 weeks and will heal in about 6 weeks, but if you do an opening-wedge osteotomy, it can take 3-6 months to fully heal."

Dr Bert says some of his patients are extremely active and may not stay off their feet long enough for an opening-wedge HTO to heal. Putting too much weight on the joint too soon after an opening-wedge HTO increases the risk for nonunion; therefore, patients who are unlikely to comply with rehabilitation protocols are probably better candidates for a closing-wedge HTO.

"Closing-wedge HTO is also better for smokers. Their impaired blood flow and delayed healing results in worse outcomes with opening-wedge HTO," Dr Bert says. His female patients typically prefer opening-wedge procedures, however, because "the cosmesis is better."

A 2014 Cochrane review found insufficient evidence to favor one HTO technique over another, and pooled data revealed no significant differences between methods regarding outcomes of pain or nonunion at the osteotomy site.[3] Although closing-wedge HTO was associated with a significantly lower risk for reoperation to remove hardware than all other HTO methods combined, this finding was limited by the low number and quality of trials available for analysis.[3]

Recently, investigators for a randomized clinical trial reported that patients with knee osteoarthritis who underwent closing-wedge HTO had a significantly greater risk for conversion to TKA after 6 years than patients who underwent an opening-wedge HTO (P = .05).[12] Only 16% of trial participants required a TKA, however, supporting the efficacy of both osteotomy techniques.

Bone-marrow stimulation, osteochondral allograft/autograft transplant, implantation of autologous chondrocytes (the cells that produce cartilage), and other cartilage procedures are often done at the same time as HTO, but Dr Bert says none of them help.

"Studies show that if you perform drilling, abrasion arthroplasty, or microfracture along with HTO, there is no difference in clinical outcomes between 1 and 9 years. There's no reason to do any of these procedures with an HTO," says Dr Bert.[13,14,15]

He notes that a retrospective study by Jung and colleagues[15] observed no difference in fibrocartilage formation between patients who had HTO alone vs patients who had HTO combined with subchondral drilling.

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