Objectives: To compare the spatiotemporal gait parameters and satisfaction of transfemoral amputees using a prosthesis with Chulalongkorn University (CU) polycentric and four-bar linkage knee units.

Study design: A pilot randomized, crossover design.

Setting: Department of Rehabilitation Medicine, King Chulalongkorn Memorial Hospital, Thailand.

Subjects: Transfemoral amputees using a prosthesis in daily life

Methods: Participants were randomly allocated by block randomization into 2 groups. The knee unit of prostheses used in both groups was changed to the CU polycentric and four-bar linkage knee units but in different sequences. Gait parameters were analyzed by using gait analysis when walking at a comfortable speed.

Results: Of the 10 participants, 80 percent were classified as K3 level of functional classification. The mean duration of amputation was 24 years (SD 16) years and mean daily prosthesis use was 6.8 (SD 2.1) hours. There was not a significant difference in gait speed, step length, and cadence of prosthesis side and contralateral side (p > 0.05) between the two knee units. However, double limb support time when using the CU polycentric knee unit was statistically significant longer than using the four-bar linkage knee unit (mean difference 0.05 second, 95%CI 0.003- 0.100, p = 0.04). Amputee satisfaction level and perception of knee stability showed no significant difference between knee units.

Conclusion: Using the CU polycentric knee unit seems feasible and acceptable for K2-K3 transfemoral amputees.  However, further development and testing are required before use in clinical practice.