Canadian Prosthetics Orthotics Journal最新文献

Bracing remains the cornerstone of non-surgical management for adolescent idiopathic scoliosis (AIS) with an aim to minimize the risk of progression and to avoid spine surgery. In Canada however, one third to half of patients present with curve magnitudes too severe for optimal brace treatment, resulting in higher than necessary surgical volumes. High-cost spine surgeries are fully funded while non-surgical management is not. This Professional Opinion article highlights systemic barriers to early detection that limit opportunity for non-surgical management in Canada and ultimately drive up healthcare spending. In Canada, there is an urgent need for a coordinated national strategy to re-establish routine scoliosis screening, ensure equitable public funding for treatment and expand professional training in non-surgical spinal care.

[This corrects the article DOI: 10.33137/cpoj.v7i1.44002.].

Background: A transfemoral bone-anchored prosthesis (TF-BAP) can be fitted with non-microprocessor-controlled knees (N-MPKs), or with microprocessor-controlled knees, which can be passive (P-MPKs) or active (A-MPKs). The next generation of A-MPKs, including powered knees, is emerging. The understanding of the loading applied on TF-BAP fitted with these A-MPKs is limited.

Objective: This cross-sectional study aimed to characterize the load applied on instrumented TF-BAP fitted with an A-MPK (Power Knee, Össur, Iceland) during standardized daily activities. Furthermore, some load characteristics applied during walking were compared with TF-BAP fitted with N-MPK and P-MPK reported in the literature using similar approach.

Methodology: Thirteen males fitted with a transfemoral press-fit osseointegrated implant participated in this study between 2021 and 2022. Forces and moments applied on the instrumented TF-BAP, fitted with a Power Knee (PKA01) and Pro-Flex (LP, XC) or Balance S feet (ÖSSUR, Iceland), were measured wirelessly using an iPecsLab (RTC Electronics, USA) during walking, ascending and descending ramp and stairs. We followed a 28-step process to characterize the loading pattern considering spatiotemporal gaits variables as well as loading boundaries and extrema.

Findings: Overall, 1,327 steps were analyzed. The cadence ranged between 34 ± 6 and 49 ± 13 strides/min. The maximum forces and moments recorded on the long, anteroposterior and mediolateral axes of the transducer were 1,258 N, 331 N and 234 N as well as 19 Nm, 74 Nm and 91 Nm, respectively.

Conclusion: The Power Knee, combined with Pro-Flex or Balance S feet, may improve participants' capacity to ambulate. Comparations with reference values indicated that transitions from N-MPKs or P-MPKs to the Power Knee are considered safe and likely to improve efficiency. This study contributed to evidence-based recommendations of TF-BAP fitted with powered knees. Hopefully, this work will advance clinical practice guidelines for the growing population choosing bionic solutions.

Background: Use of a microprocessor-controlled knee (MPK) compared to a non-microprocessor-controlled knee (NMPK) can lead to improved walking ability, confidence and satisfaction. However, the MPK is more expensive than the NMPK and it is unknown whether the higher costs outweigh the potential benefits.

Objective: To evaluate the cost-utility and cost-effectiveness of MPKs and NMPKs from a societal perspective in the Netherlands.

Methodology: Participants completed the Dutch version of the EuroQol - five dimensions - five levels (EQ-5D-5L) to assess health-related quality of life, three subscales (ambulation, utility and well-being) of the Prosthesis Evaluation Questionnaire (PEQ) to assess prosthesis-related quality of life and a cost-questionnaire from societal perspective. Incremental cost-utility ratio (ICUR) and incremental cost-effectiveness ratio (ICER) were calculated and the ICUR was compared with the Dutch willingness-to-pay threshold. Bootstrapping was used to estimate statistical uncertainty, and multiple imputation was applied to account for missing values.

Findings: In total, 111 participants were included (37 female, 73 male, 1 unknown; 71 transfemoral, 39 knee disarticulation, 1 unknown; age 64 ± 13 years; 49 NMPK users, 62 MPK users). The cost-utility analysis demonstrated that the MPK yielded an increase of 0.032 quality adjusted life years (QALY) but at considerably higher costs. The mean cost difference was € 14,626, resulting in a mean ICUR of € 457,063 per QALY gained. The cost difference was mainly driven by acquisition costs but was partially compensated by lower costs of work absence, health care consumption and household care.

Conclusion: The cost-effectiveness analyses demonstrated that the MPK is likely to provide benefits in term of prosthesis-specific quality of life, but at higher costs. However, short-term (6 months) improvement in health-related quality of life was too small to result in substantial QALY gain to offset the higher costs of the MPK and result in an incremental cost-utility ratio below the generally accepted willingness-to-pay thresholds.

Background: Accurate placement of anatomical markers is essential for valid three-dimensional (3D) gait analysis, yet individuals with lower-limb amputation (LLA) pose unique challenges due to altered anatomy, prosthetic interfaces, and increased adiposity.

Objective: This study assessed within- and between-session reliability of pelvis marker placement and static posture kinematics in adults with unilateral LLA.

Methodology: Fourteen adults with unilateral LLA (age: 58 ± 15 years, height: 174.6 ± 7.5 cm, body mass: 91.1 ± 27.7 kg, BMI: 29.6 ± 7.5 kg/m²; eleven transtibial, three transfemoral) participated in two sessions spaced 3-13 months apart. Reliability of marker distances and static posture kinematics were assessed using intraclass correlation coefficients (ICC) and standard error of measurement (SEM).

Findings: Within-session reliability of pelvis marker distances was good to excellent (ICC ≥ 0.78), whereas between-session reliability was lower (ICC as low as 0.14), particularly for posterior superior iliac spine markers. Pelvis kinematics demonstrated moderate reliability within sessions (average ICC ≈ 0.71), but trunk kinematics showed poor reliability. SEM values were low (<5°), suggesting acceptable absolute consistency despite variable ICCs, likely driven by postural changes and prosthetic factors.

Conclusion: Findings support reliable pelvis marker placement within sessions but highlight challenges for longitudinal consistency. Multiple trial collections and standardised posture protocols are recommended to improve long-term reliability.

Background: Evaluating prosthetic socket fit and function relies on accurately simulating load transfer between the residual limb and the socket. This limb can be either real (of a study participant) or a mock residual limb that simulates in vivo properties. Mock limbs minimize reliance on resource-intensive clinical trials; however, most are static in size, limiting their use in testing clinical outcomes like socket adjustability.

Objective: To design and validate a biofidelic mock limb, capable of real-time, controllable volume adjustments of up to ±5% limb volume.

Methodology: Water-filled bladders were embedded within a transtibial residual limb model made of a dual-durometer urethane composition, mimicking deep and soft tissue. An Arduino-controlled syringe system was used to actuate volume adjustments. The method was validated through repeatability tests at different rates of volume change, cycling through expansion, holding at maximum volume, and contraction. Volume change was quantified by measuring interfacial pressures between the limb and a static socket.

Findings: The limb was fabricated with readily available materials for less than CAD 400. Volume change rate had minimal effect on interfacial pressure throughout the testing cycle, and minimal hysteresis was found between expansion and contraction periods. Repeatability was high, with a coefficient of variation of normalized pressure remaining below 10.4% over three repeated tests.

Conclusion: The proposed biofidelic limb was validated for its ability to mimic volume change in a transtibial residual limb. The design enables easy replication or customization to simulate different limb physiologies and anatomies. The limb allows for controllable bench-top testing during prototyping of adjustable sockets or other devices, thus bringing devices to clinical use sooner.

Background: Increasing balance and stability, along with efficient locomotion, is a high-priority goal of physical rehabilitation after limb loss in order to facilitate effective participation in society. Research in the general population suggests that the ability to walk fast is correlated to good performance in balance tests. However, it is unclear if and how prosthesis use influences this correlation.

Objective: Our small-sample pilot study aimed to explore whether the general relationship between walking speed and balance holds true for people with limb loss whose physical capabilities are inevitably influenced by their prosthetic devices.

Methodology: Participants with any level of limb loss were recruited and asked to perform the Ten-Meter Walk Test and Narrowing Beam Walking Test. Scores in both tests were analyzed using Spearman's rank correlation coefficient.

Findings: The initial sample of eleven participants was reduced to eight (5 males, 3 females, mean age 52 years, mean height 171 cm, mean weight 68 kg, mean BMI 23, limb loss levels ranging from partial hand to trans-femoral amputation) after removing outliers. The mean Ten-Meter Walking velocity was 1.16 m/s, and the mean Narrowing Beam Test score was 11.38. The results indicate a medium to strong correlation between fast walking speed and high balance scores (ρ = 0.681, p = 0.063) when outliers are excluded.

Conclusion: These findings are consistent with prior research conducted in other populations. However, outliers in our data suggest that this relationship is not universal across all individuals with limb loss. Possible confounding variables include the activity level and the respectively prescribed prosthetic technology. Our finding, that gait speed and balance scores should be evaluated separately to tailor rehabilitation strategies effectively, is preliminary and needs to be confirmed in a larger study.