A study of long-term outcomes after medial opening wedge high tibial osteotomy for knee osteoarthritis suggests the procedure is associated with significant and sustained improvements in pain, function, quality of life, and gait biomechanics.
At the OARSI 2021 World Congress, PhD candidate Codie Primeau, MSc, of the Fowler Kennedy Sport Medicine Clinic at the University of Western Ontario, London, presented the findings from a 10-year prospective cohort study of 102 patients with symptomatic medial compartment knee osteoarthritis who underwent medial opening wedge high tibial osteotomy but did not get a total knee replacement during the study.
The surgical procedure aims to correct malalignment by redistributing knee joint loads away from the affected compartment of the knee, with the ultimate goal of slowing disease progression and improving pain and function, Mr. Primeau told the conference, which was sponsored by the Osteoarthritis Research Society International.
At 10 years, the procedure was associated with a mean 14.3-point improvement in the 0-100 Knee Injury and Osteoarthritis Outcome Score (KOOS) for pain, a mean 12-point improvement in the score for function in daily living, a 15.5-point improvement in the score for function in sport and recreation, and a 24.5-point improvement in knee-related quality of life score. Researchers also saw a 35%-45% reduction in the magnitude of the external knee adduction moment from baseline, and a gradual reduction in the knee flexion moment over the course of the study.
While the improvements did decline somewhat over the 10 years, 53% of patients still met the criteria for responder at the end of the follow-up period, meaning that they had a relative change of at least 20% in both KOOS pain and function scores, and an absolute change of at least 10 points.
Mr. Primeau noted that the patient population represented those who were the best candidates for high tibial osteotomy, in that they were keen to avoid total knee replacement.
“While these types of patients may have the best outcomes, our studies suggest patients traditionally not considered ideal candidates for HTO [high tibial osteotomy] – such as females, and patients with limited disease in other knee compartments – also have large improvements in pain and function after HTO, and around 70% of those patients do not get a total knee replacement within 10 years,” he said in an interview.
Mr. Primeau suggested that the improvements achieved with high tibial osteotomy might extend the time before a knee replacement is required, or even help some patients avoid it altogether.
“Importantly, recent studies show HTO does not complicate future joint replacement surgery,” he said. “One can get a knee replacement after HTO; the reverse is not possible.”
The ideal patient for a high tibial osteotomy would be one whose osteoarthritis was confined to the medial compartment of the knee, was younger – in their 40s or 50s – and with relatively high activity levels, he said. Some studies also suggest better outcomes in men than women.
In response to an audience question about the rehabilitation requirements after high tibial osteotomy, Mr. Primeau commented that the design of the plates used in the procedure have changed over time, and this has influenced rehabilitation needs. When the study began, patients needed anywhere from 8 to 12 weeks of no weight bearing, using crutches, to allow for bone consolidation to occur.
“Since then, plate designs have changed a lot, and patients are able to start ambulating as early as 2 weeks after the surgery now,” he said. The rehabilitation is similar to what is required for knee osteoarthritis in general, focusing on range of motion, strengthening, proprioception, and muscle training.
No conflicts of interest were declared.