Prosthetic Knee Research Articles

Effects of a low-cost prosthetic knee on amputee gait over uneven and even terrains.

Limited data are available related to using a low-cost prosthetic knee while walking. To address this gap, this study compared the performance of a low-cost prosthetic knee with 2 more advanced prosthetic knees while walking on even and uneven terrains. Two adult subjects with above-knee amputations completed walking trials using a low-cost prosthetic knee (ReMotion knee) and their personal prosthetic knees (Ottobock 3R60 Pro mechanical knee and Ossur Rheo microprocessor knee) over even and uneven terrains. Several measures of gait performance were obtained including step size, stability, energy expenditure, as well as user perception of ReMotion workload and performance during gait. Effects of the ReMotion knee were different between the mechanical and microprocessor knee user. In addition, subjects perceived the positive aspects associated with the ReMotion knee to be its lightweight feature and their perceived increased in stability during walking while both subjects disliked the inability of the ReMotion knee to adjust to preferred walking speeds. This study provided an understanding of low-cost prosthetic technology among lower-limb amputees compared to prosthetic technology with more technologically advanced assistance. These findings may help guide future low-cost prosthetic knee design considerations for use on various terrains.

Design and development of an EMG controlled transfemoral prosthesis

Electromyography (EMG) signals are biomedical signals that measure electrical currents generated by the activity of muscles when they contract. EMG is essential for optimizing the control of various prosthetic devices, particularly for transfemoral amputees, where the complexity of muscle signal integration presents significant challenges. The proposed study aims to develop a prosthetic knee that actuates in real-time using the EMG signals from the amputee’s residual limb. Pre-processing techniques are employed to obtain EMG signals from the femoris and vastus muscle targets in the transfemoral region. Moving average filters and Butterworth bandpass filters are implemented to process the raw signals. Sliding windows of various widths were applied for feature extraction. The window size of 200 ms is determined for our study based on the outcomes of the t-SNE plots and the corresponding silhouette scores. After the extraction of the pertinent features, several supervised classifier algorithms are put into practice to classify the knee flexion and extension motion. The k-nearest Neighbor (KNN) algorithm, with an accuracy rating of 80 %, proved to be suitable for motor control. Real-time control is implemented using the Raspberry Pi board to power the prosthesis allowing above-the-knee amputees to voluntarily move the leg back and forth. The EMG signals are then extracted and used to drive the DC motor. The prosthesis would therefore be able to move more precisely since the EMG readings are being gathered in real-time. Thus, this work can enhance the patient’s comfort with the ease of carrying out knee movements.

Trajectory tracking control of a four-bar linkage prosthetic knee with magnetorheological damper

In order to improve biomimicry, a four-bar linkage prosthetic knee with magnetorheological (MR) damper was developed in this paper. The principle and structure of four-bar linkage MR prosthetic knee was introduced and its kinetic model was established. A MR damper matching the proposed prosthetic knee was designed, fabricated and tested, and the forward and inverse mechanical model were conducted. In addition, to solve the problems of complex model, poor bionics and low trajectory tracking accuracy in the MR prosthetic knee, a PD-type iterative learning control (ILC) controller was developed. The simulated and experimental test results show that the positive maximum error of the knee joint swing trajectory based on PD-type ILC controller are 2.2°(speed of 0.5 m/s), 4.1°(speed of 1.0 m/s), and 1.9°(speed of 1.5 m/s), respectively, and the negative maximum error of that are −1.4°(speed of 0.5 m/s), −6.7°(speed of 1.0 m/s), and −5.5°(speed of 1.5 m/s), respectively, which effectively tracks the reference swing trajectory.

Case Report : Brucella infection of total knee arthroplasty - The first case report in an endemic country!

Prosthetic joint loosening due to Brucella spp. is a rare event. In this report, we describe a rare case of prosthetic infection caused by brucella. A 71-year-old woman reported a six-month history of progressing pain in the right prosthetic knee, which had been implanted for arthrosis four years prior to admission, associated with fever. No night sweats were noted. On examination, the right knee appeared slightly swollen and painful on mobilization, and the surgical wound was normal. Blood tests showed increased C-Reactive Protein (CRP) (34mg/L) and erythrocyte sedimentation rate (ESR) (34mm/hr). A CT scan of her right knee was performed, showing loosening of the prosthesis, joint effusion, and osteolysis in contact with the internal tibial component measuring 16mm maximum with bone remodeling of the epiphysis and metaphysis regions. Rose Bengal test was positive for brucellosis, a standard brucella tube agglutination test was positive at a titer of 1/80, blood cultures for brucella were negative and a PCR for detection of Mycobacterium tuberculosis was negative. The patient was diagnosed as having Brucella infection of his total knee arthroplasty. Favorable outcome was observed after medical and surgical treatment. We believe this is the first detailed report of Brucella prosthetic infection in the country despite the endemicity of this type of zoonosis.

Kinematic and kinetic parameters of prosthetic knee joints during walking – Comparison of gait analysis results and internal sensor data

Kinematic and kinetic parameters of prosthetic knee joints during walking – Comparison of gait analysis results and internal sensor data

Cognitive load in individuals with a transfemoral amputation during single- and dual-task walking: a pilot study of brain activity in people using a socket prosthesis or a bone-anchored prosthesis.

To explore cognitive load in people with transfemoral amputations fitted with socket or bone-anchored prostheses by describing activity in the left and right dorsolateral prefrontal cortices during single- and dual-task walking. Cross-sectional pilot study. 8 socket prosthesis users and 8 bone-anchored prosthesis users. All were fitted with microprocessor-controlled prosthetic knees. Participants answered self-report questionnaires and performed gait tests during 1 single-task walking condition and 2 dual-task walking conditions. While walking, activity in the dorsolateral prefrontal cortex was measured using functional near-infrared spectroscopy. Cognitive load was investigated for each participant by exploring the relative concentration of oxygenated haemoglobin in the left and right dorsolateral prefrontal cortex. Symmetry of brain activity was investigated by calculating a laterality index. Self-report measures and basic gait variables did not show differences between the groups. No obvious between-group differences were observed in the relative concentration of oxygenated haemoglobin for any walking condition. There was a tendency towards more right-side brain activity for participants using a socket prosthesis during dual-task conditions. This pilot study did not identify substantial differences in cognitive load or lateralization between socket prosthesis users and bone-anchored prosthesis users.

Prevalence and risk factors for haematogenous periprosthetic joint infection during Staphylococcus aureus bacteraemia

Background Staphylococcus aureus bacteraemia (SAB) may lead to periprosthetic joint infections (PJI) via haematogenous spread of bacteria to the joint. Due to the risk of PJI, patients with SAB and prosthetic joint are recommended prolonged antibiotic treatment. The aim of the study was to assess the risk of PJI during SAB, and to evaluate if short treatment duration affects outcomes in patients with uncomplicated SAB and prosthetic joints without clinical signs of PJI. Methods Patients with growth of S. aureus in blood cultures were cross-referenced against the Swedish Arthroplasty register to identify patients with prosthetic hip or knee joints at the time of SAB. Medical records were reviewed to identify PJI at the time of SAB and during a 6-month follow-up period. Results Out of 400 patients with SAB and a prosthetic joint, 281 met all eligibility criteria and were included in the study. Of the included participants, 35 (12%) had a haematogenous PJI. Younger age and presence of multiple prosthetic joints were associated with an increased risk of PJI. Of the 247 patients without signs of PJI at the initial SAB episode, 118 patients (48%) had an uncomplicated infection and received short total antibiotic treatment (median 15 days, IQR 13-17). The risk of PJI during the follow-up period was low (<1%) and similar in the uncomplicated group compared to patients with complicated SAB that received longer antibiotic treatment (median 29 days, IQR 15-70). Conclusion The prevalence of haematogenous PJI was lower than previously reported. Our data do not support prolonged antibiotic treatment in patients with SAB and prosthetic joints without clinical signs of PJI.

MyKnee: Mechatronic Design of a Novel Powered Variable Stiffness Prosthetic Knee

MyKnee: Mechatronic Design of a Novel Powered Variable Stiffness Prosthetic Knee

Hoffa's fat pad resection during total knee arthroplasty does not affect functioning and gait: a double-blind randomized clinical trial.

Hoffa's fat pad is considered a source of anterior knee pain and may limit prosthetic knee function. Resection of Hoffa's fat pad in total knee arthroplasty (TKA), however, is controversial, and little is known about the functional outcomes including gait quality. This double-blind randomized controlled trial (i) compared functional recovery between TKAs where Hoffa was resected or preserved, and (ii) compared recovery of self-reported function with objective (gait-related) outcomes. Eighty-five patients (age 66.4 ± 8.0 years, 47% women) scheduled to undergo TKA for primary osteoarthritis were randomly assigned to either fat pad resection or preservation. Subjective measures of functioning were assessed at baseline, 6 weeks, 3 months, and 12 months postoperatively and included the Knee Injury and Osteoarthritis Outcome Score (KOOS), Kujala, and visual analog scale (VAS) for pain. Objective measures of functioning were assessed at baseline, 3 months, and 12 months postoperatively and included instrumented range-of-motion and gait analysis. Longitudinal analyses (generalized estimating equations) were used to compare recovery between groups, and chi-square tests compared attainment of minimal clinical important difference (MCID) and patient acceptable symptom state (PASS). Finally, correlation analyses explored associations between subjective and objective recovery in function. Resection patients showed poorer improvement in KOOS quality of life in the first 6 weeks (B=-10.02, 95% confidence interval (CI) [-18.91, -1.12], p = .027), but stronger improvement in knee extension after 3 months (B = 3.02, 95%CI [0.45, 5.60], p = .021) compared to preservation patients. Regarding MCID or PASS, no differences were noted between groups at 3 and 12 months (all p > .05). Subjective function substantially improved in the first 3 months, while objective outcomes improved only between 3 and 12 months. Moderate to strong correlations were identified between changes in knee flexion and gait with Kujala and KOOS in the resection but not in the preservation group. Similar functional outcomes were achieved after TKA with or without resection of Hoffa's fat pad. Hence, removing the fat pad to promote surgical exposure will not affect functional outcomes including gait quality. Functional recovery of objective outcomes was not always consistent with subjective recovery, suggesting that both self-reported as well as objective, gait-related outcomes may provide meaningful information on functional recovery following TKA. This clinical trial was prospectively registered under the Netherlands Trial Registry (# NL3638). This registry has recently been replaced by the Dutch Trial Registry where this study can be accessed via https://onderzoekmetmensen.nl/en/trial/20994 .

Paediatric Prosthetic Knee Design: The Technical Requirements of a Swing Phase Control Mechanism are Correlated with Parameters of Childhood Growth.

There is a lack of innovation in affordable prosthetic knee joints for children. One significant reason is the absence of technical requirements which consider the foundation of childhood: growth. This study aims to develop and use a modelling tool to determine the technical requirements throughout childhood growth for one prosthetic knee design feature, a swing phase control mechanism (SPCM). 3D gait data of 31 able-bodied children across a range of physical maturities were analyzed. For each participant 2 models were created from a validated paediatric able-bodied musculoskeletal model. The model was first linearly scaled, then a corresponding unilateral right knee-disarticulation amputation model produced by removing segments below the knee and replacing with prosthetic componentry. Long established low-cost prosthetic componentry and a novel polycentric knee were implemented. For each participant, inverse dynamics were conducted and the SPCM torque requirements defined. Prosthetic knee SPCM torque requirements were significantly less than the able-bodied knee to emulate able-bodied gait at free speed: 17.9% (± 10.2) and 66.3% (± 17.0) reduction in maximum extension and flexion torque, respectively. Maximum knee extension torque showed the strongest negative correlation with intact body mass (ρ = -0.6251) whereas flexion torque showed the strongest correlation with height (ρ = 0.6611). Corresponding linear regression fits produced RMSE of 1.91and 1.73 Nm, respectively. Results were also determined for slow and fast speeds. The torque requirements of an affordable paediatric prosthetic knee SPCM are defined and found to strongly correlate with parameters of childhood growth (body mass, height, and age). Current results recommend low-cost paediatric prosthetic SPCM designs can be tailored to accommodate growth. The creation of musculoskeletal models facilitate multiple future studies.

FHIR-standardized data collection on the clinical rehabilitation pathway of trans-femoral amputation patients

Lower limb amputation is a medical intervention which causes motor disability and may compromise quality of life. Several factors determine patients’ health outcomes, including an appropriate prosthetic provision and an effective rehabilitation program, necessitating a thorough quantitative observation through different data sources. In this context, the role of interoperability becomes essential, facilitating the reuse of real-world data through the provision of structured and easily accessible databases. This study introduces a comprehensive 10-year dataset encompassing clinical features, mobility measurements, and prosthetic knees of 1006 trans-femoral amputees during 1962 hospital stays for rehabilitation. The dataset is made available in both comma-separated values (CSV) format and HL7 Fast Healthcare Interoperability Resources (FHIR)-based representation, ensuring broad utility and compatibility for researchers and healthcare practitioners. This initiative contributes to advancing community understanding of post-amputation rehabilitation and underscores the significance of interoperability in promoting seamless data sharing for meaningful insights into healthcare outcomes.

Hip and knee arthroplasty in one surgical session: early morbi-mortality study

IntroductionBilateral prosthetic hip or knee replacement in one surgical session is a procedure that has been widely validated in the literature, whereas hip and knee replacement in one surgical session remains poorly documented. This study reports on the results of these procedures by analyzing early post-operative complications in a retrospective multicenter study. Material and methodsBetween 2009 and 2023, 51 patients underwent hip and knee replacement surgery in a single surgical session at 4 French centers. They were 24 men and 27 women, with a mean age of 68.8 years (36–87); 7 patients were ASA 1, 30 were ASA 2 and 14 ASA 3. Prosthetic hip replacement was always performed first, associated 33 times with the ipsi-lateral knee and 18 times with the contralateral knee. All early complications, within the first 90 days post-operatively, were recorded: death, phlebitis, pulmonary embolism, myocardial infarction, surgical site infection (SSI), knee stiffness treated by mobilization under general anesthesia, urinary tract infection, acute urine retention or any other adverse event related to care. Transfusion rates were also reported. ResultsThe rate of early complications was 9.8% (5/51). No deaths, no phlebitis, no pulmonary embolism and no SSI were observed. Complications included one myocardial infarction, one urinary tract infection, one superficial infection, one haematoma treated by surgical evacuation and one recurrent instability requiring revision surgery (hip arthroplasty). The transfusion rate was 17.6% (9/51). The complication rate of ASA 3 patients was higher than that of ASA 1 and 2 patients, while there was no difference related to age or BMI. DiscussionOur results confirm the feasibility of single-stage hip and knee replacement, with a low complication rate in ASA 1 and 2 patients. This study adds to the few published works on the subject and reports comparable results. The small sample size and the heterogeneity of patients and centers limit the scope of the results, these limitations being relative to the volume expected for a rare procedure. ConclusionSingle-session hip and knee arthroplasty should be reserved for patients selected according to comorbidities: ASA score, age and body mass index. ASA 3 patients have a higher risk of complications. Level of evidenceIV; retrospective

Effect of Multiantibiotic-Loaded Bone Cement on the Treatment of Periprosthetic Joint Infections of Hip and Knee Arthroplasties-A Single-Center Retrospective Study.

Two-stage septic revision is the prevailing method for addressing late periprosthetic infections. Using at least dual-antibiotic-impregnated bone cement leads to synergistic effects with a more efficient elution of individual antibiotics. Recent data on the success rates of multiantibiotic cement spacers in two-stage revisions are rare. We conducted a retrospective follow-up single-center study involving 250 patients with late periprosthetic hip infections and 95 patients with prosthetic knee infections who underwent septic two-stage prosthesis revision surgery between 2017 and 2021. In accordance with the antibiotic susceptibility profile of the microorganisms, a specific mixture of antibiotics within the cement spacer was used, complemented by systemic antibiotic treatment. All patients underwent preoperative assessments and subsequent evaluations at 3, 6, 9, 12, 18, and 24 months post operation and at the most recent follow-up. During the observation period, the survival rate after two-step septic revision was 90.7%. Although survival rates tended to be slightly lower for difficult-to-treat (DTT) microorganism, there was no difference between the pathogen groups (easy-to-treat (ETT) pathogens, methicillin-resistant staphylococci (MRS), and difficult-to-treat (DTT) pathogens). Furthermore, there were no differences between monomicrobial and polymicrobial infections. No difference in the survival rate was observed between patients with dual-antibiotic-loaded bone cement without an additional admixture (Copal® G+C and Copal® G+V) and patients with an additional admixture of antibiotics to proprietary cement. Employing multiple antibiotics within spacer cement, tailored to pathogen susceptibility, appears to provide reproducibly favorable success rates, even in instances of infections with DTT pathogens and polymicrobial infections.

Current Concepts in Management of Distal Femur Fractures

Recent studies report the overall incidence of distal femur fractures as 8.7/100,000/year. This incidence is expected to rise with high energy motor vehicle collisions and elderly osteoporotic fractures in native and prosthetic knees keep increasing. These fractures are more common in males in the younger age spectrum while females predominate for elderly osteoporotic fractures. Surgical treatment is recommended for these fractures to maintain articular congruity, enable early joint motion and assisted ambulation. Over the last two decades, development of minimally invasive and quadriceps sparing surgical approaches, availability of angle stable implants have helped achieve predictable healing and early return to function in these patients. Currently, laterally positioned locked plate is the implant of choice across all fracture patterns. Retrograde with capital implantation of intramedullary nails with provision for multiplanar distal locking is preferred for extra-articular and partial articular fractures. Even with these advancements, nonunion after distal femur fracture fixation can be as high as 19%. Further recent research has helped us understand the biomechanical limitations and healing problems with lateral locked plate fixation and intramedullary nails. This has lead to development of more robust constructs such as nail-plate and double plate constructs aiming for improved construct strength and to minimise failures. Early results with these combination constructs have shown promise in high risk situations such as fractures with extensive metaphyseal fragmentation, osteoporosis and periprosthetic fractures. These constructs however, run the risk of being over stiff and can inhibit healing if not kept balanced. The ideal stiffness that is needed for fracture healing is not clearly known and current research in this domain has lead to the development of smart implants which are expected to evolve and may help improve clinical results in future.

Comparing the lower limb joint biomechanics of the Power Knee, C-Leg and Rheo Knee during ramp and stair ambulation

One of the most significant developments in prosthetic knee technology has been the introduction of the Microprocessor-Controlled Prosthetic Knee (MPK). However, there is a lack of consensus over how different types of MPKs affect performance in different ambulation modes. In this study, we investigated the biomechanical differences in ramp and stair maneuvers when an individual with transfemoral amputation wears three commercial MPKs: the Össur Power Knee, the Össur Rheo Knee and the Ottobock C-Leg 4. The primary outcome variable for this study was the lower limb biological joint work, inclusive of the intact leg and prosthetic side hip. We hypothesized that (1) the Power Knee would result in lower biological work during ascent activities than the C-Leg and Rheo, both passive MPKs, and (2) the C-Leg and Rheo would result in lower biological work during descent activities than the Power Knee. During ramp ascent, the C-Leg was associated with lower biological joint work (p < 0.05) than the Power Knee. However, this relationship did not hold during stair ascent, where the Power Knee showed advantages for stair ascent with net reductions in biological joint work of 14.1% and 23.3% compared to the Rheo and C-leg, respectively. There were no significant differences in biological joint work between the knees during ramp and stair descent, indicating that choice of MPK may not be as important for descent activities. Our results demonstrate that differences are present between different types of MPKs during ascent activities which could prove useful in the prescription of these devices.

Lightweight design of prosthetic knee joint based on variable density method

Abstract The variable density method has emerged as an efficient approach for tackling the topology optimization challenge in continuous structures. In response to the increasing demand for lightweight prosthetic joints, a lightweight design was conducted, focusing on the front linkage rod - a crucial component of prosthetic joints. This study employed Altair Inspire software to optimize the motion-based topology of the front linkage rod. Additionally, the optimized model underwent geometric reconstruction and strength analysis. Subsequently, both the pre- and post-lightweight models were subjected to 3D printing to determine the weight reduction ratio. After confirming that the weight reduction ratio fell within the acceptable error range, a lightweight model was successfully achieved, exhibiting a remarkable weight reduction of 68.61% when compared to the initial model. This research introduces a fresh perspective on the lightweight design of prosthetic joints in motion, offering valuable insights for future endeavors in this field.

Static simulation of polycentric prosthetic knee for structural compliance

Static simulation of polycentric prosthetic knee for structural compliance

Biomechanical effects of adding an articulating toe joint to a passive foot prosthesis for incline and decline walking.

Walking on sloped surfaces is challenging for many lower limb prosthesis users, in part due to the limited ankle range of motion provided by typical prosthetic ankle-foot devices. Adding a toe joint could potentially benefit users by providing an additional degree of flexibility to adapt to sloped surfaces, but this remains untested. The objective of this study was to characterize the effect of a prosthesis with an articulating toe joint on the preferences and gait biomechanics of individuals with unilateral below-knee limb loss walking on slopes. Nine active prosthesis users walked on an instrumented treadmill at a +5° incline and -5° decline while wearing an experimental foot prosthesis in two configurations: a Flexible toe joint and a Locked-out toe joint. Three participants preferred the Flexible toe joint over the Locked-out toe joint for incline and decline walking. Eight of nine participants went on to participate in a biomechanical data collection. The Flexible toe joint decreased prosthesis Push-off work by 2 Joules during both incline (p = 0.008; g = -0.63) and decline (p = 0.008; g = -0.65) walking. During incline walking, prosthetic limb knee flexion at toe-off was 3° greater in the Flexible configuration compared to the Locked (p = 0.008; g = 0.42). Overall, these results indicate that adding a toe joint to a passive foot prosthesis has relatively small effects on joint kinematics and kinetics during sloped walking. This study is part of a larger body of work that also assessed the impact of a prosthetic toe joint for level and uneven terrain walking and stair ascent/descent. Collectively, toe joints do not appear to substantially or consistently alter lower limb mechanics for active unilateral below-knee prosthesis users. Our findings also demonstrate that user preference for passive prosthetic technology may be both subject-specific and task-specific. Future work could investigate the inter-individual preferences and potential benefits of a prosthetic toe joint for lower-mobility individuals.

Effect of Surgeon Volume on Mechanical Complications after Resection Arthroplasty with Articulating Spacer.

Two-stage revision with an antibiotic-loaded cement articulating spacer is a standard treatment for chronic prosthetic knee infection (PKI); however, mechanical complications can occur during the spacer period. There is limited evidence on the association between surgeon volume and mechanical complications after resection arthroplasty (RA) using an articulating spacer. This study aimed to compare the rates of mechanical complications and reoperation after RA with articulating spacers by surgeons with high volumes (HV) and low volumes (LV) of RA performed and analyzed the risk factors for mechanical failure. The retrospective study investigated 203 patients treated with PKIs who underwent RA with articulating spacers and were divided according to the number of RAs performed by the surgeons: HV (≥14 RAs/year) or LV (<14 RAs/year). Rates of mechanical complications and reoperations were compared. Risk factors for mechanical complications were analyzed. Of the 203 patients, 105 and 98 were treated by two HV and six LV surgeons, respectively. The mechanical complication rate was lower in HV surgeons (3.8%) than in LV surgeons (36.7%) (p < 0.001). The reoperation rate for mechanical complications was lower in HV surgeons (0.9%) than in LV surgeons (24.5%) (p < 0.001). Additionally, 47.2% of patients required hinge knees after mechanical spacer failure. Medial proximal tibial angle < 87°, recurvatum angle > 5°, and the use of a tibial spacer without a cement stem extension were risk factors for mechanical complications. Based on these findings, we made the following three conclusions: (1) HV surgeons had a lower rate of mechanical complications and reoperation than LV surgeons; (2) mechanical complications increased the level of constraint in final revision knee arthroplasty; and (3) all surgeons should avoid tibial spacer varus malalignment and recurvatum deformity and always use a cement stem extension with a tibial spacer.

An enhancement of the Genium™ microprocessor-controlled knee improves safety and different aspects of the perceived prosthetic experience for unilateral and bilateral users.

Bilateral microprocessor-controlled prosthetic knee (MPK) users have unique needs in traversing environmental barriers compared to unilateral users. An enhancement to the Genium™/Genium X3™ MPK which included an updated ruleset, hydraulics, and new bilateral parameter presets was made to improve safety while stumbling and the smoothness of gait for all users while also improving the experience of bilateral users. The purpose of the study was to evaluate the effectiveness of the enhancements in a sample with unilateral and bilateral amputation. A convenience sample of MPK users was recruited from two sites in the USA in two phases. Assessments included the L-Test of Functional Mobility, Activity-specific Balance Confidence Scale, Prosthetic Limb User Survey of Mobility, a study-specific questionnaire, and the Comparative Activities of Daily Living (ADL) Questionnaire. Statistical significance of extracted data was tested with the Wilcoxon Rank-Sum Test for independent data and Wilcoxon Signed-Rank for paired data with an a priori significance level of p < 0.05. Unilateral subjects were age-matched to the group of bilateral subjects for between-groups and within-groups analyses. Twenty-six subjects (n = 26) were enrolled. Stumble frequency reduced 85% from 16.0 ± 39.7 to 2.4 ± 2.3 (p = 0.008) between baseline and final assessment overall. The bilateral group reported 50% (p = 0.009) and 57% (p = 0.009) greater relative improvement in patient-reported ease and safety, respectively, of completing ADLs compared to the unilateral group. The unilateral group reported residual limb pain and low back pain reduced from 2.3 to 1.4 (p = 0.020) and 3.8 to 1.8 (p = 0.027), respectively, whereas the bilateral group did not. Substantial reductions in stumbles, residual limb pain, and back pain were shown overall. These reductions were driven by the unilateral group who also showed improvements in comfort, exertion, and concentration while walking. The enhancements to the knee likely reduced some gait asymmetry for unilateral users. Improvements in patient-reported ease and safety of completing ADLs were shown overall and were driven by the bilateral group. This study shows further improvement in patient experience is achievable through innovation in MPK technology even for patients who appear to be functioning well.