Joint motion, surgery type tied to knee replacement outcomes
Researchers in China studied 87 hemophilia patients about success of procedure
A greater range of motion before surgery is associated with better post-surgical outcomes for people with hemophilia who undergo knee replacement surgery.
That’s according to a recent study that also found that having the surgery on both knees at the same time had a negative impact on the overall efficacy of the procedure. The study, “Influencing factors of the outcome of patients with haemophilia after knee replacement–a retrospective study,” was published in BMC Musculoskeletal Disorders.
In hemophilia, a deficiency in certain proteins involved in blood clotting results in unusually easy and prolonged bleeding. In most cases, the deficiency is caused by mutations in a gene that provide instructions for making a specific clotting factor protein.
Recurrent bleeding in the joints, particularly the knee joints, can lead to permanent and irreversible joint damage, pain, and limited mobility. In severe cases, procedures, such as joint replacement surgery, may help ease these symptoms.
Researchers in China conducted a retrospective analysis to identify factors that may influence the success of knee replacement surgery in 87 hemophilia patients who had the procedure at their hospital from January 2012 to December 2020. All of them received knee prostheses.
The surgery’s efficacy was assessed using several measures, including the Hospital for Special Surgery (HSS) knee score, the American Knee Society’s Clinical (KSC) and Functional (KSF) scores, the degree of contracture, which are deformities caused by soft tissue tightening and stiffness, range of motion, and wound healing. Based on these measures, 74 of the 117 knees analyzed were deemed to have excellent outcomes, while the remaining 43 had poor outcomes.
Factors affecting good, poor outcomes
Many of the individual criteria used to separate the patients into the two groups were significantly associated with better outcomes after surgery. These included having a greater range of knee motion before surgery, fewer contractures, and better HSS, KSC, and KSF scores. Less severe hemophilia and less pain before surgery, as indicated by a visual analog scale (VAS), were also linked to better outcomes.
All seven patients who underwent quadriceps plasty to release leg muscles to improve their range of motion were placed in the poor group, as were many who had surgery in both knees at the same time. Having depression and other mental health problems were also related to poorer outcomes.
No significant differences between the groups were found in age, body mass index (body fat content), the cumulative number of affected joints, hemophilia type, coagulation factor treatment route, hospital stay duration, or hip-knee angle.
The range of knee motion before surgery and the simultaneous replacement of two knees appeared to be significant predictors of knee replacement outcomes. Every one degree of presurgical range of motion was linked to a 0.162-times increase in the likelihood of an excellent outcome. Moreover, the probability of a poor outcome more than doubled when both knees were replaced simultaneously over a single replacement.
Overall, knee replacement surgery significantly improved various clinical assessments, including KSC, KSF, HSS, and VAS scores. Patients also saw their range of motion increase after the procedure and had fewer contractures.
There were significantly more knee bleeds in the poor than in the excellent group (15 vs. 5 bleeds). Stiffness requiring manipulation under anesthesia also occurred more often in the poor outcome group (16 vs. 2 knees). Five knees required additional surgery, all in the poor group.
All the patients who achieved an excellent outcome were still alive after 10 years, compared with 88.4% of those with poor outcomes.
“The study concludes that the efficacy of knee joint replacement surgery in hemophilia patients is influenced by the pre-[range of motion] and simultaneous bilateral knee replacement,” the researchers wrote. “Better preoperative knee joint mobility is associated with improved outcomes, whereas simultaneous bilateral knee replacement negatively impacts surgical efficacy.”
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