Clinical Evaluation and Gait Characteristics before and after Total Knee Arthroplasty Based on a Portable Gait Analyzer.

OBJECTIVE: To evaluate the effects of surgery and rehabilitation on patients undergoing total knee arthroplasty (TKA).

METHODS: Twelve patients and 12 healthy controls were enrolled and their clinical scores evaluated by a doctor. Gait data, including walking velocity, stride length, single support time, foot fall and swing power, were collected using a portable gait analyzer from 12 patients before and 6 weeks and 6 months after surgery and from 12 healthy controls. The gait data and clinical scores at selected time points were compared and correlations between gait characteristics and clinical scores assessed.

RESULTS: Clinical knee and knee function scores increased significantly from before surgery to 6 weeks to 6 months after surgery (P < 0.001). The only significant differences identified were for single support time on the diseased side between before surgery and 6 months after surgery (P = 0.031) and for foot fall with the diseased side between 6 weeks and 6 months after surgery (P = 0.016). Foot fall and speed of the healthy or diseased sides were significantly different in patients at all time points from those of the healthy subjects (P < 0.05). Single support time on the diseased side was significantly different 6 months after surgery (P = 0.035) in patients than in healthy controls. Single support time on the healthy side before surgery was significantly different from that of healthy controls (P = 0.048) and 6 weeks after surgery (P = 0.042). Stride lengths differed significantly between patients and healthy subjects before surgery (healthy side: P = 0.007; diseased side: P = 0.008) and 6 weeks after surgery (healthy side: P = 0.001; diseased side: P = 0.001), but were not different at 6 months after surgery (healthy side: P = 0.088; diseased side: P = 0.077). The only significant correlations identified were between single support time with the diseased side of patients and their knee (r = 0.43, P = 0.032) and knee function scores (r = 0.493, P = 0.012).

CONCLUSIONS: A portable gait analyzer appears to be suitable for evaluating the effects of TKA. Single support time on the diseased side may be a sensitive quantitative index for determining the effect of TKA and rehabilitation.