Socket size adjustments in people with transtibial amputation: Effects on residual limb fluid volume and limb-socket distance

BackgroundSmall intermittent adjustments of socket size using adjustable sockets may be a means for people with transtibial amputation to better maintain residual limb fluid volume and limb position while using a prosthesis.MethodsSocket size, limb fluid volume, and distance from the limb to the socket, termed “sensed distance,” were recorded while participants with transtibial amputation walked on a treadmill wearing a motor-driven, cabled-panel, adjustable socket. Researchers made frequent socket size adjustments using a mobile phone app to identify participants' acceptable socket size range. Limb fluid volume and sensed distance were then monitored as incremental adjustments were made to the socket.FindingsProsthesis users in this study (n = 10) accepted socket sizes between −5% and +5% of their neutral socket volume. There was a rapid increase in limb fluid volume and sensed distance upon socket enlargement, and a rapid decrease upon reduction. Subsequently, there were gradual changes in fluid volume and sensed distance. While visually monitoring limb fluid volume data in real time, researchers were able to adjust socket size to maintain consistent limb fluid volume within a −0.7% to +0.9% volume change for 24 min.InterpretationParticipant residual limbs compensated to socket size adjustment. Using socket-mounted sensors to monitor limb-socket mechanics, an automatic adjustable socket that maintains limb fluid volume may be possible and may improve socket fit in instances where fit deteriorates during use.     

Interface pressure in transtibial socket during ascent and descent on stairs and its effect on patient satisfaction

BackgroundTranstibial amputees encounter stairs and steps during their daily activities. The excessive pressure between residual limb/socket may reduce the walking capability of transtibial prosthetic users during ascent and descent on stairs. The purposes of the research were to evaluate the interface pressure between Dermo (shuttle lock) and Seal-In X5 (prosthetic valve) interface systems during stair ascent and descent, and to determine their satisfaction effects on users.MethodsTen amputees with unilateral transtibial amputation participated in the study. Interface pressure was recorded with F-socket transducer (9811E) during stair ascent and descent at self-selected speed. Each participant filled in a questionnaire about satisfaction and problems encountered with the use of the two interface systems.FindingsThe resultant mean peak pressure (kPa) was significantly lower for the Dermo interface system compared to that of the Seal-In X5 interface system at the anterior, posterior and medial regions during stair ascent (63.14 vs. 80.14, 63.14 vs. 90.44, 49.21 vs. 66.04, respectively) and descent (67.11 vs. 80.41, 64.12 vs. 88.24, 47.33 vs. 65.11, respectively). Significant statistical difference existed between the two interface systems in terms of satisfaction and problems encountered (P < 0.05).InterpretationThe Dermo interface system caused less pressure within the prosthetic socket compared to the Seal-In X5 interface system during stair negotiation. The qualitative survey also showed that the prosthesis users experienced fewer problems and increased satisfaction with the Dermo interface system.     

Residual limb osteomyelitis: A case series from a national prosthetic centre

Purpose. To examine the impact of residual limb osteomyelitis (RLO) on the rehabilitation of lower limb amputees.

Method. Retrospective review of the casenotes of patients with RLO. Information sought included details of amputation, clinical features of investigations for and management of RLO and its effect on rehabilitation.

Results. There were seven transfemoral and three transtibial amputees. Indications for amputation were vascular disease in nine cases, trauma in one. In each case, delayed wound healing or residual limb pain prompted radiological, hematological and microbiological investigations. Average time between amputation and diagnosis was 187 days. One patient died before treatment commenced. Two transtibial amputees were treated with intravenous antibiotics while rehabilitating using pylons. The remaining seven transfemoral amputees required surgical intervention and intravenous antibiotics. Five achieved independent ambulation following modification to or replacement of the originally cast prosthesis, averaging 408 days between amputation and commencement of rehabilitation. Two patients have not engaged in rehabilitation.

Conclusion. RLO delays rehabilitation and has significant financial implications, incurred by prolonged hospitalisation, radiological investigations and prosthetic modifications. RLO should be considered in any case of delayed wound healing or residual limb pain in amputees, as earlier diagnosis may reduce the time to commencement of rehabilitation and subsequent independent ambulation.     

Á priori alignment of transtibial prostheses: a comparison and evaluation of three methods

Purpose: The objectives of this study were to compare three á priori alignment methods and evaluate them based on initial gait quality and further alignment changes required to optimize gait. Á priori alignment is requisite for monolimbs, transtibial prostheses in which the socket and pylon are made from one piece of plastic, because monolimbs have no alignment adjustability. Method: The three methods investigated were traditional bench alignment (TRAD), vertical alignment axis (VAA) and anatomical based alignment (ABA). Endoskeletal components were utilized for the study, rather than monolimbs, so that alignment could be experimentally manipulated. Three endoskeletal prostheses were aligned, one according to each á priori method, for each of seven subjects. Gait and alignment data were captured, dynamic alignment was performed to optimize gait, and data were captured again. Results: VAA and TRAD methods required less change compared to ABA in socket flexion angle. Looking at subjects individually, VAA produced a better alignment and better gait for the greatest number of subjects. Conclusions: A new refined method of á priori alignment is proposed based on the results of this study, and is applicable for á priori alignment of monolimbs or any type of transtibial prosthesis.

Implications for Rehabilitation

• This study shows that there is a wide range of acceptable alignments for a transtibial prosthesis.

• Using the best possible alignment for a monolimb could produce a high-quality transtibial prosthesis at a great cost savings.

     

Pressure distribution at the stump/socket interface in transtibial amputees during walking on stairs, slope and non-flat road

BACKGROUND: Studies examining the stump/socket interface stresses have been restricted to unsupported stance and natural gait, i.e. walking at a comfortable speed on flat and straight walkway. However, the pressure behaviour as to the interface in unilateral transtibial amputees during walking on stairs, slope and non-flat road is unclear. METHODS: Pressure distribution changes at multiple points, expressed as mean peak stump/socket interface pressure, mean pressure level over 90% of peak pressure, time in which pressure exceeded 90% of peak pressure and time-pressure integral at the period of sustained sub-maximal load, were measured during natural ambulating and walking on stairs, slope and non-flat road. FINDINGS: Compared with natural gait, the mean peak pressure and sustained sub-maximal load increase notably over the patellar tendon during walking on stairs and non-flat road, and however decrease or change insignificantly at the patellar tendon on slope and over other measured areas in all conditions; moreover the time period of sustained sub-maximal load changes remarkably, except over the patellar tendon during walking up slope and over the popliteal area on non-flat road; finally, the time-pressure integral in the time period of sustained sub-maximal load changes considerably, except at the patellar tendon during walking up slope. INTERPRETATION: The pressure characteristics during natural ambulating seem not to be highly predictive of what occurs in the conditions of walking on stairs, slope and non-flat road, which leads to significant increase in amplitude domain of tissue loading only at the patellar tendon, and however to remarkable changes in temporal sequences of tissue (un-)loading almost in all measured regions.     

Temperature measurement and control system for transtibial prostheses: Single subject clinical evaluation

The snug fit of a prosthetic socket over the residual limb can disturb thermal balance and put skin integrity in jeopardy by providing an unpleasant and infectious environment. The prototype of a temperature measurement and control (TM&C) system was previously introduced to resolve thermal problems related to prostheses. This study evaluates its clinical application in a setting with reversal, single subject design. The TM&C system was installed on a fabricated prosthetic socket of a man with unilateral transtibial amputation. Skin temperature of the residual limb without prosthesis at baseline and with prosthesis during rest and walking was evaluated. The thermal sense and thermal comfort of the participant were also evaluated. The results showed different skin temperature around the residual limb with a temperature decrease tendency from proximal to distal. The TM&C system decreased skin temperature rise after prosthesis wearing. The same situation occurred during walking, but the thermal power of the TM&C system was insufficient to overcome heat build-up in some regions of the residual limb. The participant reported no significant change of thermal sense and thermal comfort. Further investigations are warranted to examine thermography pattern of the residual limb, thermal sense, and thermal comfort in people with amputation.     

Comparison of transhumeral socket designs utilizing patient assessment and in vivo skeletal and socket motion tracking: a case study

Purpose: This case study compares the impact of two prosthetic socket designs, a “traditional” transhumeral (TH) socket design and a Compression Released Stabilized (CRS) socket. Methods: A CRS socket was compared to the existing socket of two persons with transhumeral amputation. Comparisons included assessments of patient comfort and satisfaction with fit, as well as dynamic kinematic assessment using a novel high-speed, high-resolution, bi-plane video radiography system (XROMM, for X-ray Reconstruction of Moving Morphology). Results: Subjects were more satisfied with the comfort of the traditional sockets, although they had positive impressions about aspects of the fit and style of the CRS socket, and thought that it provided better control. Dynamic kinematic assessment revealed that the CRS socket provided better control of the residual limb within the socket, and had less slippage as compared to a traditional TH socket design. Conclusions: The TH CRS socket provided better control of the residual limb within the socket, and had less slippage. However, participants were less satisfied with the comfort and overall utility of the CRS socket, and stated that additional fitting visits/modifications to the CRS socket were needed. It is possible that satisfaction with the CRS socket may have improved with prosthetic adjustment and more acclimation time.

• Implications for Rehabilitation

• A comfortable, good fitting prosthetic socket is the key factor in determining how long (or if) an upper limb amputee can tolerate wearing a prosthesis.

• This case series was a comparison of two socket designs, a 'traditional' socket design and a Compression Released Stabilized (CRS) socket design in persons with transhumeral amputation.

• The CRS socket provided better control of the residual limb within the socket, and had less slippage. However, its tightness made it more difficult to don.

• Both subjects were less satisfied with the comfort and overall utility of the CRS socket. However, satisfaction might have been improved with additional fitting visits and more acclimation time.

     

Clinical investigation of the interface pressure in the trans-tibial socket with Dermo and Seal-In X5 liner during walking and their effect on patient satisfaction

BACKGROUND: The interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. Liners provide a comfortable interface by adding a soft cushion between the residual limb and the socket. The Dermo and the Seal-In X5 liner are two new interface systems and, due to their relative infancy, very little are known about their effect on patient satisfaction. The aim of this study was to compare the interface pressure with these two liners and their effect on patient satisfaction. METHODS: Nine unilateral transtibial amputees participated in the study. Two prostheses were fabricated for each amputee, one with the Seal-In liner and one with the Dermo liner. Interface pressure was measured at the anterior, posterior, medial and lateral regions during walking on the level ground. Each subject filled in a Prosthetic Evaluation Questionnaire (PEQ) regarding the satisfaction with the two liners. Findings The mean peak pressures with the Seal-In liner was 34.0% higher at the anterior, 24.0% higher at the posterior and 7.0% higher at the medial regions of the socket (P=0.008, P=0.046, P=0.025) than it was with the Dermo Liner. There were no significant differences in the mean peak pressures between the two liners at the lateral regions. In addition, significant difference was found between the two liners both for satisfaction and problems (P<0.05). Interpretation There was less interface pressure between the socket and the residual limb with the Dermo liner. The results indicated that the Dermo liner provides more comfort in the socket than the Seal-In liner.     

Biomechanical risk factors for knee osteoarthritis when using passive and powered ankle–foot prostheses

BackgroundGait compensations following transtibial amputation negatively affect sound limb loading and increase the risk of knee osteoarthritis. Push-off assistance provided by new powered prostheses may decrease the demands on the sound limb. However, their effects in a young population in the early stages of prosthetic use are still unknown. The purpose of this study was to compare limb loading between 1. passive and powered ankle–foot prostheses, 2. sound and amputated limbs, and 3. individuals with amputations in the relatively early stages of prosthetic use and controls.MethodsTen young, active individuals with unilateral transtibial amputation and 10 controls underwent biomechanical gait analysis at three speeds. The peak external knee flexor and adductor moments, adductor moment's angular impulse, peak vertical ground reaction force and loading rate were calculated. Repeated measures ANOVAs compared between limbs, prostheses, and groups.FindingsThe powered prosthesis did not decrease the sound limb's peak adduction moment or its impulse, but did decrease the external flexor moment, peak vertical force and loading rate as speed increased. The powered prosthesis decreased the loading rate from controls. The sound limb did not display a significantly greater risk for knee osteoarthritis than the intact limb or than controls in either device.InterpretationIn the early stages of prosthetic use, young individuals with transtibial amputation display few biomechanical risk factors for knee osteoarthritis development. However, a powered ankle–foot prosthesis still offers some benefits and may be used prophylactically to mitigate potential increases of these variables with continued prosthetic use over time.     

Clinical evaluation of two prosthetic suspension systems in a bilateral transtibial amputee

ABSTRACT: The effects of Seal-In X5 and Dermo liner (?ssur) on suspension and patient's comfort in lower limb amputees are unclear. In this report, we consider the case of a 51-yr-old woman with bilateral transtibial amputation whose lower limbs were amputated because of peripheral vascular disease. The subject had bony and painful residual limbs, especially at the distal ends. Two prostheses that used Seal-In X5 liners and a pair of prostheses with Dermo liners were fabricated, and the subject wore each for a period of 2 wks. Once the 2 wks had passed, the pistoning within the socket was assessed and the patient was questioned as to her satisfaction with both liners. This study revealed that Seal-In X5 liner decreased the residual limb pain experienced by the patient and that 1-2 mm less pistoning occurred within the socket compared with the Dermo liner. However, the patient needed to put in extra effort for donning and doffing the prosthesis. Despite this, it is clear that the Seal-In X5 liner offers a viable alternative for individuals with transtibial amputations who do not have enough soft tissue around the bone, especially at the end of the residual limb.     

The validity of forceplate data as a measure of rapid and targeted volitional movements of the centre of mass in transtibial prosthesis users

Purpose: To validate outcome variables from the limits of stability protocol that are derived from the center of pressure with those same variables derived from the center of mass during rapid, volitional responses in transtibial prosthesis users.

Method: Prosthesis users (n?=?21) and matched controls (n?=?21) executed movements while force and motion data were collected. Correlation coefficients were used to investigate relationships between center of pressure and center of mass for: x/y coordinates positions, limits of stability outcome variables and muscular reaction times.

Results: Significant differences were seen in correlation between x/y coordinate positions toward the intact limb (mean effect size of differences: r?=?.38). Limits of stability variables were positively correlated (reaction time and maximum excursion range r_s: .585–.846; directional control and mean velocity range r_s: .307–.472). Muscular reaction times correlated weakly with those from center of pressure (mean r_s prosthesis users: .186 and controls: .101).

Conclusions: Forceplate measures are valid in describing rapid, volitional movements in unilateral transtibial prosthesis users. Limits of stability outcomes extracted from center of pressure and center of mass are highly correlated, but can be sensitive to direction. Muscular reaction time correlates very little with reaction times extracted from the other variables.

• Implications for rehabilitation

• Rehabilitation programs utilizing limits of stability are valid measures of postural control in transtibial prosthesis users.

• Clinicians interpreting the outcomes from limits of stability need to be aware of their varying validity.

• Muscular reaction times correlate weakly with other measures of reaction time, highlighting the complexity of rapidly coordinating volitional movements in prosthesis users.

     

Strength and endurance training of an individual with left upper and lower limb amputations

Purpose:?The purpose of this article is to describe the development of a strength and endurance training programme designed to prepare an individual with a left glenohumeral disarticulation and transtibial amputation for a bike trip across the USA.

Method:?The subject was scheduled for training three times per week over a two-month period followed by two times per week for an additional two months. Training consisted of a resistance training circuit using variable resistance machines, cycling using a recumbent stationary bike, and core stability training using stability ball exercises. Changes in strength were assessed using 10 RM tests on the resistance machines and changes in peak VO₂ were monitored utilizing the Cosmed K4b²® pulmonary function tester.

Results:?The subject demonstrated a 30.3% gain in peak VO₂. The subject's 10 RM for left single limb leg press increased 36.8% and gains of at least 7.7% were seen for all other muscle groups tested.

Conclusion:?The strength and endurance training programme adapted to compensate for this subject's limb losses was effective in increasing both strength and peak VO₂. Adapting exercise programmes to compensate for limb loss may allow individuals with amputations to participate in physically challenging activities that otherwise may not be available to them.     

Individual responses to alignment perturbations in socket reaction moments while walking in transtibial prostheses

Background

The alignment of transtibial prostheses has a systematic effect on the mean socket reaction moments in amputees. However, understanding their individual differences in response to alignment perturbations is also important for prosthetists to fully utilize the socket reaction moments for dynamic alignment in each unique patient. The aim of this study was to investigate individual responses to alignment perturbations in transtibial prostheses with solid-ankle-cushion-heel feet.

Methods

A custom instrumented prosthesis alignment component was used to measure the socket reaction moments while walking in 11 amputees with transtibial prostheses under 17 alignment conditions, including 3° and 6° of flexion, extension, abduction, and adduction of the socket, 5 mm and 10 mm of anterior, posterior, lateral, and medial translation of the socket, and an initial baseline alignment. Coronal moments at 30% of stance and maximum sagittal moments were extracted for comparisons from each amputee.

Findings

In the coronal plane, varus moment at 30% of stance was generally reduced by adduction or medial translation of the socket in all the amputees. In the sagittal plane, extension moment was generally increased by posterior translation or flexion of the socket; however, this was not necessarily the case for all the amputees.

Interpretations

Individual responses to alignment perturbations are not always consistent, and prosthetists would need to be aware of this variance when addressing individual socket reaction moments during dynamic alignment in clinical setting.     

Comparison of energy cost in transtibial amputees using "prosthesis" and "crutches without prosthesis" for walking activities

BackgroundIn a survey of 100 transtibial amputees (TTA) in the study place, it was noticed that nearly 30% of total activities performed by crutches. It was recorded nearly 52% of the amputees were totally independent, 39% had to use a crutch or cane and only 9% need not used any devices simply because they are unaware of current technology or availability. Out of 39 TTA, nine used crutches only for performing daily activities while 30 used both prosthesis and crutch. Walking is a major activity in lower limb amputees and therefore it is imperative to know the energy cost in both the mobility devices (prosthesis and crutches without prosthesis) for walking activities.ObjectivesThe purpose of this study was to quantify and compare the difference in energy cost between the two most commonly used assistive devices (prosthesis and axillary crutches) in adults with Transtibial amputation by indirect calorimetric method at the self-selected speed in plane surface walking.MethodsThirty adults who had a unilateral transtibial amputation participated in this study. Oxygen consumption was measured with a Cosmed K4 b² oxygen analysis telemetry unit (Rome, Italy) as the participants walked over level ground for 30 meters at a self-selected speed. The variables that were analyzed were VO₂ rate (mL/min), VO₂ cost (mL/kg/m), heart rate (bpm), self-selected walking velocity (m/min) and energy expenditure per minute (Kcal/min).ResultsIt was observed that VO₂ uptake rate and EE comparisons were highly significant for both prosthesis and crutches without prosthesis walking in adults with transtibial amputation (P < 0.025). There was significant difference between prosthesis walking and crutches without prosthesis walking in terms of VO₂ uptake rate (P < 0.005) and EE/min (P < 0.00001). It was noticed the adults with transtibial amputation using prosthesis walked with 21% more efficient in terms of VO₂ uptake rate and 92% more efficient in terms of EE/min as compared to crutches without prosthesis.ConclusionsThe data on energy cost indicates that all below knee amputee groups walk with less effort by using prosthesis. It may be concluded that crutches without prosthesis may not be used as a permanent rehabilitative measure in transtibial amputations.     

An experimental study of the interface pressure profile during level walking of a new suspension system for lower limb amputees

Background

Different suspension systems that are used within prosthetic devices may alter the distribution of pressure inside the prosthetic socket in lower limb amputees. This study aimed to compare the interface pressure of a new magnetic suspension system with the pin/lock and Seal-In suspension systems.

Methods

Twelve unilateral transtibial amputees participated in the study. The subjects walked on a level walkway at a self-selected speed. The resultant peak pressure with the three different suspension systems was recorded using F-socket transducers.

Findings

There were significant statistical differences between the three studied suspension systems. Pair-wise analyses revealed that the mean peak pressure (kPa) was lower with the magnetic system than it was with the pin/lock system over the anterior and posterior aspects during one gait cycle (89.89 vs. 79.26 and 47.22 vs. 26.01, respectively). Overall, the average peak pressure values were higher with the Seal-In system than they were with the new magnetic lock and pin/lock system.

Interpretation

The new magnetic system might reduce the pressure within the prosthetic socket in comparison to the pin/lock and Seal-In system during one gait cycle. This is particularly important during the swing phase of gait and may reduce the pain and discomfort at the distal residual limb in comparison to the pin/lock system.     

Amputation rehabilitation and prosthetic restoration. From surgery to community reintegration

Purpose:?The purpose of this review is to summarize the literature related to the advances that have taken place in the management and rehabilitation care of limb amputation.

Results:?Prostheses for the lower and upper limb amputee have changed greatly over the past several years, with advances in components, socket fabrication and fitting techniques, suspension systems and sources of power and electronic controls. Higher levels of limb amputation can now be fitted with functional prostheses, which allow more patients to achieve independent life styles. This is of particular importance for the multi-limb amputee. The rehabilitation of more traditional lower limb levels of amputation have also greatly benefited from the technological advances including energy storing feet, electronic control hydraulic knees, ankle rotators and shock absorbers to mention a few. For the upper limb amputee, myoelectric and proportional controlled terminal devices and elbow joints are now used routinely in some rehabilitation facilities. Experimental prosthetic fitting techniques and devices such as the use of osseo-implantation for suspension of the prosthesis, tension control hands or electromagnetic fluids for knee movement control will also be briefly discussed in this paper.

Conclusion:?It is possible to conclude from this review that many advances have occurred that have greatly impacted the functional outcomes of patients with limb amputation.     

Shape and volume change in the transtibial residuum over the short term: preliminary investigation of six subjects

A preliminary investigation was conducted to characterize the magnitude and distribution of volume change in transtibial residua at two time intervals: upon prosthesis removal and at 2 week intervals. Six adult male unilateral transtibial amputee subjects, between 0.75 and 40.0 years since amputation, were imaged 10 times over a 35-minute interval with a custom residual limb optical scanner. Volume changes and shape changes over time were assessed. Measurements were repeated 2 weeks later. Volume increase on socket removal for the six subjects ranged from 2.4% to 10.9% (median 6.0% +/- standard deviation 3.6%). Rate of volume increase was highest immediately upon socket removal and decreased with time (five subjects). In four subjects, 95% of the volume increase was reached within 8 minutes. No consistent proximal-to-distal differences were detected in limb cross-sectional area change over time. Limb volume differences 2 weeks apart ranged from -2.0% to 12.6% (0.6% +/- 5.5%) and were less in magnitude than those within a session over the 35-minute interval (five subjects). Multiple mechanisms of fluid movement may be responsible for short-term volume changes, with different relative magnitudes and rates in different amputees.     

Effect of prosthetic gel liner thickness on gait biomechanics and pressure distribution within the transtibial socket

Prosthetic gel liners are often prescribed for persons with lower-limb amputations to make the prosthetic socket more comfortable. However, their effects on residual limb pressures and gait characteristics have not been thoroughly explored. This study investigated the effects of gel liner thickness on peak socket pressures and gait patterns of persons with unilateral transtibial amputations. Pressure and quantitative gait data were acquired while subjects walked on liners of two different uniform thicknesses. Fibular head peak pressures were reduced (p = 0.04) with the thicker liner by an average of 26 +/- 21%, while the vertical ground reaction force (GRF) loading peak increased 3 +/- 3% (p = 0.02). Most subjects perceived increased comfort within the prosthetic socket with the thicker liner, which may be associated with the reduced fibular head peak pressures. Additionally, while the thicker liner presumably increased comfort by providing a more compliant limb-socket interface, the higher compliance may have reduced force and vibration feedback to the residual limb and contributed to the larger vertical GRF loading peaks. We conclude that determining optimal gel liner thickness for a particular individual will require further investigations to better identify and understand the compromises that occur between user perception, residual-limb pressure distribution, and gait biomechanics.