Good Long-term Outcomes After Knee Replacement in Hemophilia Patients, Study Finds

Most people with hemophilia who undergo knee replacement surgery have favorable outcomes, including less pain and improved function, a new single-center study from South Korea reports.

The study, “Mid-to Long-Term Survival of Total Knee Arthroplasty in Hemophilic Arthropathy,” was published in the Journal of Clinical Medicine.

Hemophilia can result in joint disease called hemophilic arthropathy. When it becomes severe, knee replacement surgery — also called total knee arthroplasty (TKA) — often is performed in order to reduce pain and increase function.

Although performing TKA has shown benefits in people with hemophilia, existing studies generally have reported only short- or mid-term results. Studies with longer follow-up periods have included a limited number of patients and have been conducted at multiple sites.

“The aim of this study was therefore to evaluate the long-term results of primary TKA in patients with hemophilia performed at a single institution,” the researchers wrote

They identified 56 people with hemophilia who underwent TKA (on a total of 78 knees; 70 from patients with hemophilia A and eight from those with hemophilia B) at Kyung Hee University Hospital at Gangdong from 2007 to 2015.

All surgeries were performed by two surgeons. Patients were given replacement therapy before the procedure to restore their factor levels to 100%. Six patients with high levels of neutralizing antibodies to clotting factors were treated with activated recombinant factor VII.

At the time of surgery, the mean age of patients was 38.7 years. Mean follow-up time was 10.2 years.

Before and after surgery, knees were evaluated using the American Knee Society (AKS) score, which has two subscores — a “knee” score and a “function” score. An AKS score of 70 to 84 is considered good, a score of 85 or higher is considered excellent, and a score below 59 points is considered poor.

Results showed that the average AKS knee score improved from 32.1 before surgery to 85.7 after the procedure. Likewise, the function score improved from 41.5 to 83.3 post-surgery.

The average range of motion for the knees, or their extent of movement, also  increased significantly: from 64.2 degrees before surgery to 84.2 degrees at the most recent follow-up. Lower limb alignment (based on imaging of the leg bones) also improved significantly following TKA.

Having inhibitors did not affect clinical improvements experienced with surgery.

Patients also experienced significant improvements in physical and mental quality of life after surgery, as assessed with the Short Form-36.

Post-surgery complications occurred in 12 knees (15.4%). Within one month, five knees required hospital readmission due to reasons such as stiffness or joint bleeding. Three knees (3.9%) needed revision TKA due to joint infection or loosening of the bond between implant and bone.

At 10 years of follow-up, 76 (97.4%) of the knee replacements were in place. By 13 years, all but one (96.2%) remained in place.

“The main finding of the current study is that mid-to long-term results of TKA in patients with end-stage hemophilic arthropathy were satisfactory in terms of pain relief, functional improvement, and radiologic outcomes,” the researchers concluded.