Comparison of nonmicroprocessor knee mechanism versus C-Leg on Prosthesis Evaluation Questionnaire, stumbles, falls, walking tests, stair descent, and knee preference

Abstract

Abstract-This study compared subjects' performance with a nonmicroprocessor knee mechanism (NMKM) versus a C-Leg on nine clinically repeatable evaluative measures. We recorded data on subjects' performance while they used an accommodated NMKM and, following a 90-day accommodation period, the C-Leg in a convenience sample of 19 transfemoral (TF) amputees (mean age 51 +/-19) from an outpatient prosthetic clinic. We found that use of the C-Leg improved function in all outcomes: (1) Prosthesis Evaluation Questionnaire scores increased 20% (p = 0.007), (2) stumbles decreased 59% (p = 0.006), (3) falls decreased 64% (p = 0.03), (4) 75 m selfselected walking speed on even terrain improved 15% (p = 0.03), (5) 75 m fastest possible walking speed (FPWS) on even terrain improved 12% (p = 0.005), (6) 38 m FPWS on uneven terrain improved 21% (p < 0.001), (7) 6 m FPWS on even terrain improved 17% (p = 0.001), (8) Montreal Rehabilitation Performance Profile Performance Composite Scores for stair descent increased for 12 subjects, and (9) the C-Leg was preferred over the NMKM by 14 subjects. Four limited community ambulators (Medicare Functional Classification Level [MFCL] K2) increased their ambulatory functional level to unlimited community ambulation (MFCL K3). Objective evaluative clinical measures are vital for justifying the medical necessity of knee mechanisms for TF amputees. Use of the C-Leg improves performance and quality of life and can increase MFCL and community ambulation level.

Does Limb-salvage Surgery Offer Patients Better Quality of Life and Functional Capacity than Amputation?

“…Seventh, none of our patients who had AKA used any of the new advanced prosthetic legs such as the C-leg (Otto Bock; Duderstadt, Germany). Kahle et al [17] reported that use of the C-leg improves performance and quality of life and can increase community ambulation level. This will add to the argument of defining the line between amputation and limb salvage.…”

Conception, design and development of a low-cost intelligent prosthesis for one-sided transfemoral amputees

“…By utilizing specific programs and sensor information, these prostheses may result in a more natural gait (Aaron et al, 2006;Sup et al, 2008;Herr and Wilkenfeld, 2003;Johansson et al, 2005;Kahle et al, 2008;Kapti and Yucenur, 2006;Laferrier and Gailey, 2010). The main differences in the design of these prostheses are in their damping systems because an adequate damping allows for fast transitions in stride velocity, which increases the autonomy of the amputee.…”

“…Utilizing a questionnaire, Kahle et al (2008) showed that subjects who use the hydraulic-based C-leg (commercialized by Otto Bock HealthCare Deutschland, Duderstadt, Germany) demonstrated an improved performance and higher quality of life compared to subjects who use nonmicroprocessor above-knee prostheses. Johansson et al (2005) reported a clinical comparison between two variable-damping above-knee prostheses (the hydraulic-based C-leg and magneorheological-based Ossur Rheo) and a passive mechanism (hydraulic-based Mauch SNSC).…”

“…Therefore, it can be stated that microcontrolled intelligent prostheses improve damping performance as a function of the stride velocity transition, with a reduction in oxygen consumption during walking, over a wide range of velocities (Datta et al, 2005;Johansson et al, 2005;Kahle et al, 2008;Schmalz et al, 2002;Taylor et al, 1996).…”

Designs and performance of microprocessor-controlled knee joints

“…Their complex interaction of various functional principles used for generating joint resistances are implemented by control algorithms and sensor technology that directly affect movement and safety outcomes for lower-limb amputees [2][3][4]. For the patient, the resultant functional quality [2,5,8,12,17,18,24,[30][31][32], and the reduction in falls some MPKs provide [3,7,11,16], is of central importance. The challenge for prosthetic practitioners and patients alike is how to select the appropriate MPK to meet the functional needs of the lower-limb amputee.…”