Active Transfemoral Amputees Research Articles

Lifetime cost-effectiveness analysis osseointegrated transfemoral versus socket prosthesis using Markov modelling.

Prior cost-effectiveness analyses on osseointegrated prosthesis for transfemoral unilateral amputees have analyzed outcomes in non-USA countries using generic quality of life instruments, which may not be appropriate when evaluating disease-specific quality of life. These prior analyses have also focused only on patients who had failed a socket-based prosthesis. The aim of the current study is to use a disease-specific quality of life instrument, which can more accurately reflect a patient's quality of life with this condition in order to evaluate cost-effectiveness, examining both treatment-naïve and socket refractory patients. Lifetime Markov models were developed evaluating active healthy middle-aged male amputees. Costs of the prostheses, associated complications, use/non-use, and annual costs of arthroplasty parts and service for both a socket and osseointegrated (OPRA) prosthesis were included. Effectiveness was evaluated using the questionnaire for persons with a transfemoral amputation (Q-TFA) until death. All costs and Q-TFA were discounted at 3% annually. Sensitivity analyses on those cost variables which affected a change in treatment (OPRA to socket, or socket to OPRA) were evaluated to determine threshold values. Incremental cost-effectiveness ratios (ICERs) were calculated. For treatment-naïve patients, the lifetime ICER for OPRA was $279/quality-adjusted life-year (QALY). For treatment-refractory patients the ICER was $273/QALY. In sensitivity analysis, the variable thresholds that would affect a change in the course of treatment based on cost (from socket to OPRA), included the following for the treatment-naïve group: yearly replacement components for socket > $8,511; cost yearly replacement parts OPRA < $1,758; and for treatment-refractory group: yearly replacement component for socket of > $12,467. The use of the OPRA prosthesis in physically active transfemoral amputees should be considered as a cost-effective alternative in both treatment-naïve and treatment-refractory socket prosthesis patients. Disease-specific quality of life assessments such as Q-TFA are more sensitive when evaluating cost-effectiveness.

INFLUENCE OF FEMUR LENGTH ON ASYMMETRY OF PROSTHETIC GAIT BIOMECHANICS IN TRANSFEMORAL AMPUTATION

This study compares the prosthetic gait asymmetry in transfemoral amputees with varied femoral lengths to able-bodied participants in terms of temporal-spatial parameters and joint kinematics. Sixteen young and active transfemoral amputees with short and long residual limbs were divided into two groups and subjected to three-dimensional quantitative motion analysis through high definition optoelectronic cameras and force platform. The prosthetic gait of amputees was compared with those of 15 participants with normal gait to analyze the asymmetry. There was a significant difference in temporal-spatial gait parameters between the amputee groups in terms of intact limb stride length and swing time ([Formula: see text]). The gait of amputees with long femoral lengths was with comparatively higher mean step length (0.31 versus 0.35[Formula: see text]m), velocity (0.48 versus 0.44[Formula: see text]m/s), and cadence (73.58 versus 66.62 steps/min) compared to short residual limbs, however these results are nonsignificant ([Formula: see text]). Amputees and able-bodied participants differed significantly for all measured parameters ([Formula: see text]). The amputees with short residual limbs had more variation in sagittal plane hip flexion at initial contact than long amputees and able-bodied subjects. Amputees with longer residual limbs demonstrated peak swing prosthetic hip flexion closer to able-bodied individuals. The frontal pelvic obliquity and sagittal pelvic tilt revealed more variance among amputees with shorter residual limbs than longer ones. This study will aid in identifying the underlying mechanism of gait asymmetry in transfemoral amputees in relation to residual femoral length and hence will pave a path for improving the knee and foot prosthetic components.

The effects of domestic mechanical knee joints on pelvic motion in transfemoral amputees

Purpose Pelvic asymmetry in the sagittal and horizontal planes among prosthesis users is related to the strength of the abdominal and back muscles. Considering that lumbosacral pathologies and pain in long-term transfemoral prosthesis users can cause asymmetric pelvic motion, it is necessary to investigate pelvic asymmetry caused by prosthetic components. The aim was to compare the gait symmetry of the pelvis of active transfemoral amputees using different types of prosthetic knee joints (Non-microprocessor-controlled prostheses (NMCPs) and microprocessor-controlled prostheses (MCP) knees). Methods The two patient groups comprised eight transfemoral amputees: four patients had NMCP joints (Turkish products), and four patients had MCP knees. The reference group consisted of ten normal volunteers. In this work, the 3-D motion of the pelvis, hip, knee and ankle was assessed using the VICON system. Results The results revealed that during stance, the kinematics of pelvic movement in the amputee group differed from those of the control group in terms of the total excursion anterior pelvic tilt (APT) and maximum and minimum degrees of APT (p < .05). We evaluated the graphics of the NMCP and MCP knee joints and found that the prosthesis-side APT was closer to that of the control group during the stance phase among the NMCP users, while the APT of the MCP users was closer to that of the control group during the swing phase. Conclusion The investigated MCP benefitted the patients considerably. The NMCP did not provide as much walking as the MCP but produced less APT. Implications for Rehabilitation The MCP may not provide symmetrical pelvic motion during all phases of the gait cycle. In transfemoral amputees using MCP, focusing on pelvis in walking training will contribute to pre-prosthetic and post-prosthetics rehabilitation. The NMCP knee joint may be closer in terms of APT.

The prevalence of osteoarthritis: Higher risk after transfemoral amputation?-A database analysis with 1,569 amputees and matched controls.

BackgroundSeveral studies have shown that patients with a unilateral amputation have an increased risk of developing osteoarthritis (OA) in the knee of their sound leg. OBJECTIVE: The first objective was to investigate whether amputees are more frequently affected by gon-, cox- or polyarthritis as well as back pain or spinal disorders. We hypothesized that mobile and active transfemoral amputees more often experience OA and spinal disorders than non-amputees. The second objective was to compare the mean age of the patients with OA.PatientsPatients with a unilateral transfemoral amputation (n = 1,569) and five abled-body control groups (each n = 1,569) matched in terms of age and gender resulting in total of 9,414 participants.MethodsGroups were analyzed regarding the prevalence of six selected diagnoses regarding musculoskeletal disorders.ResultsA significantly decreased prevalence of OA and specific disorders of the spine in transfemoral amputees compared to a control group was found. The amputees with OA are significantly younger than patients with OA in the control group.ConclusionThe results from the presented study contradict previously published literature. Apparently circumstances of life play an important role, like physical work and strenuous activities which are likely to be underrepresented in the amputee group. The results of the study need to be used cautiously due to the major limitation of the study which is the lack of detail in individual patients caused by the methodology.

Safety and function of a prototype microprocessor-controlled knee prosthesis for low active transfemoral amputees switching from a mechanic knee prosthesis: a pilot study

Purpose: Aim of this pilot study was to assess safety and functioning of a microprocessor-controlled knee prosthesis (MPK) after a short familiarization time and no structured physical therapy.Materials and methods: Five elderly, low-active transfemoral amputees who were fitted with a standard non-microprocessor controlled knee prosthesis (NMPK) performed a baseline measurement consisting of a 3 D gait analysis, functional tests and questionnaires. The first follow-up consisted of the same test procedure and was performed with the MPK after 4 to 6 weeks of familiarization. After being refitted to their standard NMPK again, the subjects undertook the second follow-up which consisted of solely questionnaires 4 weeks later.Results: Questionnaires and functional tests showed an increase in the perception of safety. Moreover, gait analysis revealed more physiologic knee and hip extension/flexion patterns when using the MPK.Conclusion: Our results showed that although the Genium with Cenior-Leg ruleset-MPK (GCL-MPK) might help to improve several safety-related outcomes as well as gait biomechanics the functional potential of the GCL-MPK may have been limited without specific training and a sufficient acclimation period.Implications for RehabilitationElderly transfemoral amputees are often limited in their activity by safety issues as well as insufficient functioning regarding the non microprocessor-controlled knee prostheses (NMPK), thing that could be eliminated with the use of suitable microprocessor-controlled prostheses (MPK).The safety and functioning of a prototype MPK (GCL-MPK) specifically designed for the needs of older and low-active transfemoral amputees was assessed in this pilot study.The GCL-MPK showed indicators of increased safety and more natural walking patterns in older and low-active transfemoral amputees in comparison to the standard NMPK already after a short acclimatisation time and no structured physical therapy.Regarding functional performance it seems as if providing older and low-active transfemoral amputees with the GCL-MPK alone without prescribing structured prosthesis training might be insufficient to achieve improvements over the standard NMPKs.

Gait asymmetry of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees

BackgroundAmputees walk with an asymmetrical gait, which may lead to future musculoskeletal degenerative changes. The purpose of this study was to compare the gait asymmetry of active transfemoral amputees while using a passive mechanical knee joint or a microprocessor-controlled knee joint. MethodsObjective 3D gait measurements were obtained in 15 subjects (12 men and 3 women; age 42, range 26–57). Research participants were longtime users of a mechanical prosthesis (mean 20years, range 3–36years). Joint symmetry was calculated using a novel method that includes the entire waveform throughout the gait cycle. FindingsThere was no significant difference in hip, knee and ankle kinematics symmetry when using the different knee prostheses. In contrast, the results demonstrated a significant improvement in lower extremity joint kinetics symmetry when using the microprocessor-controlled knee. InterpretationUse of the microprocessor-controlled knee joint resulted in improved gait symmetry. These improvements may lead to a reduction in the degenerative musculoskeletal changes often experienced by amputees.

Gait symmetry of transfemoral amputees walking with mechanical and microprocessor-controlled prosthetic knees

INTRODUCTION The gait of a unilateral lower limb amputee is asymmetrical [1], which applies increased stress on the intact leg [2] and can cause long-term complications. The most common complications, due to this altered load distribution and gait asymmetry for people who have lived with an amputation for long time are back and/or intact limb pain [3,4], osteoarthritis in the intact limb [2,3], osteopenia/osteoporosis in the residual limb [2], and other musculoskeletal problems [4]. For the above-knee amputee (AKA), the prosthetic knee joint is one of the most critical components of the prosthesis because it influences all of these outcomes. Prosthetic knees can be classified into those that use mechanical control of the knee joint (non-microprocessor knee, NMPK) and those that use microprocessor control (MPK). The purpose of this study was to compare the gait asymmetry of active transfemoral amputees while using a NMPK compared to a MPK. We hypothesized that the patient would have improved gait symmetry when wearing a MPK.

Magnitude and variability of loading on the osseointegrated implant of transfemoral amputees during walking

This study directly measured the load acting on the abutment of the osseointegrated implant system of transfemoral amputees during level walking, and studied the variability of the load within and among amputees. Twelve active transfemoral amputees (age: 54 ± 12 years, mass: 84.3 ± 16.3 kg, height: 17.8 ± 0.10 m) fitted with an osseointegrated implant for over 1 year participated in the study. The load applied on the abutment was measured during unimpeded, level walking in a straight line using a commercial six-channel transducer mounted between the abutment and the prosthetic knee. The pattern and the magnitude of the three-dimensional forces and moments were revealed. Results showed a low step-to-step variability of each subject, but a high subject-to-subject variability in local extrema of body-weight normalized forces and moments and impulse data. The high subject-to-subject variability suggests that the mechanical design of the implant system should be customized for each individual, or that a fit-all design should take into consideration the highest values of load within a broad range of amputees. It also suggests specific loading regime in rehabilitation training are necessary for a given subject. Thus the loading magnitude and variability demonstrated should be useful in designing an osseointegrated implant system better able to resist mechanical failure and in refining the rehabilitation protocol.