Journal of Tissue Viability (2014) 23, 81e93

www.elsevier.com/locate/jtv

Review

A systematic review of the key factors affecting tissue viability and rehabilitation outcomes of the residual limb in lower extremity traumatic amputees Katrina Butler a, Catherine Bowen a, Ann-Marie Hughes a, Russel Torah b, Ivo Ayala b, John Tudor b, Cheryl D. Metcalf a,b,* a

Centre for Innovation & Leadership, Faculty of Health Sciences, University of Southampton, United Kingdom b Electronics and Computer Sciences, Faculty of Physical Sciences & Engineering, University of Southampton, United Kingdom

KEYWORDS Systematic review; Amputation; Transfemoral; Transtibial; Trauma

Abstract Most traumatic lower limb amputees ambulate using a prosthetic limb. Comfort, appearance of the missing limb and function are confirmed as being important during rehabilitation post-amputation. Emerging evidence suggests that impaired tissue viability of the stump affects rehabilitation and thus clinical ability to provide optimum care. The primary objective of this systematic review was to identify key factors relating to tissue viability of the residual limb in lower extremity traumatic amputees. A secondary objective was to identify factors that affect rehabilitation post-amputation. In total, 218 studies were assessed; 37 met pre-determined criteria. Studies were classified according to the WHO ICF framework and the NHMRC level of evidence. Five key themes emerged; Prosthetic Fit; The Residuum; Quality of Life; Amputee Care and Prosthetic Use. The evidence indicates that high frequencies of skin problems affecting tissue viability within this population are inherently linked to intolerance of the prosthesis. Stump integrity, amputee care regimen and pain were also identified as impacting on quality of life, affecting rehabilitation and the ability to become independently mobile. Levels of evidence within all studies were low and

* Corresponding author. Centre for Innovation & Leadership, Faculty of Health Sciences, University of Southampton, United Kingdom. E-mail addresses: [email protected], [email protected] (C.D. Metcalf). http://dx.doi.org/10.1016/j.jtv.2014.08.002 0965-206X/ª 2014 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

82

K. Butler et al. indicative of the majority being non-randomised cohort studies or caseecontrol studies. As there are a limited number of interventional studies, further development of robust outcome measures, clinical trials and prospective studies are of utmost importance to unravel the links between tissue viability and the other key factors. This will inform clinical management strategies and help develop targeted therapies and care pathways. ª 2014 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

1. Introduction/background An estimated 5500 people in the United Kingdom require a lower-limb amputation each year, and of these, 53% are transtibial amputation (TTA) and 39% transfemoral amputation (TFA) [1,2]. Threequarters of all referrals for lower limb amputations are due to dysvascularity, 8% due to infection and 7% of amputations are due to trauma [1]. Increased numbers of trauma-related amputations have arisen due to recent international conflicts in countries, such as Afghanistan and Iraq. Servicemen and women are surviving combat-related injuries due to improvements in body armour and field-based medical care. Although the incidence of fatality is decreasing, a notable increase has been seen in the number of casualties surviving with extremity injuries and/or consequent amputation [3e6]. While initial care and support for these wounded service personnel is provided by the UK Ministry of Defence and private health-care sector, the impact of an increasing number of amputees upon the wider community and provision of long-term care will have consequences upon the public healthcare and larger socioeconomic systems [7,8]. Given the atypical care pathway and rehabilitation needs of these patients, and with an increasing incidence, this review will focus on trauma-related amputations. Rehabilitation post-amputation will often aim to provide the patient with a prosthetic device that endeavours to replace the function and appearance of the missing limb [11,12]. These factors, in addition to comfort, have been confirmed as being important to patients [2], thus impacting prosthetic use. Conversely, poor prosthetic fit is associated with reduced adherence due to numerous pressureassociated sequelae [9,11e13]. High pressures may lead to occlusion of the cutaneous blood flow and friction between the skin and the socket [11,14]. Exposure to a combination of stresses and high loading conditions, which can lead to skin tissue breakdown and consequences of such poor fit inevitably impacts on the progress of the patient’s rehabilitation until the ulcerations have healed [15e20].

A breakdown in tissue viability at the stump can be painful for the prosthetic user, and may cause an increased risk of infection [17]. This can limit their participation in daily activities and lead to the postponement of rehabilitation programmes [15,18,21e23]. The consequent reduction in activity not only impacts physically on the patient’s life, but may also have a psychological impact due to a decreased sense of achievement and frustration at their inability to complete activities of daily living independently [2,16,18,19]. Evidence for improvements in prosthetic devices and socket technology have recently increased such that amputees may expect to exercise for longer and in more demanding environments. Inconsistencies in investigative methodologies, quality of studies and prosthetic device fabrication have however made understanding and assimilating the available evidence challenging. Given this increase in evidence, there is a growing need for robust synthesis of the quality of such information, particularly for interested groups such as key stakeholders: healthcare providers, users and policy makers. The primary objective of this systematic review was to identify key factors relating to tissue viability of the residual limb in lower extremity amputees. A secondary objective was to identify factors that affect rehabilitation post-amputation. The term “use” is applied in a broad context, from describing adherence to the physical ability of the amputee while wearing a prosthetic lower limb. The focus of this review is centred on TTA and TFA, which are the most common amputations within this population [1,2].

2. Method The four themes of the PICO (Participants, Interventions, Comparison and Outcome) [24] framework was used to identify key search terms by defining important characteristics pertaining to the review objectives. Use of the PICO is also in line with the PRISMA statement for reporting

Key factors affecting tissue viability and rehabilitation outcomes systematic reviews [25]. The PICO framework helped identify the inclusion criteria using a logical approach derived from knowledge of the subject area. The results used to derive the search strategy are shown in Table 1. Using the PICO approach, the following search terms were used: above-knee amputees, biomechanic* (* symbol meaning a ‘wildcard’ character for searching purposes), contributing, electromyography, factor, force, lower limb amputees, military, motion analysis, pressure, pressure measurement, skin integrity, skin problems, sock/stump interface, socket, stump integrity, transfemoral amputees, transtibial amputees, transfemoral, transtibial and trauma. For practical reasons, variations on these terms were also given, for example the use of hyphens “trans-femoral”, or acronyms “EMG”. Search terms were combined using Boolean Operators. The strategy was supplemented by hand searching all reference lists of potentially eligible retrieved full text articles. Only full text articles available in English and that fulfilled the PICO criteria were included. The full search strategy is available in Appendix A. The following databases were searched: Ovid, Allied and Complementary Medicine (AMED); CAB abstracts; Embase; Health management Information Consortium (HMIC) and the RECAL legacy database (a database specifically for prostheticsrelated research). All databases were searched from their inception until August 2013. The NHMRC Evidence Hierarchy [26] was used to categorise the methodological quality of each study, whereby:
Level I is a systematic review of Level II studies;

Table 1

83


Level II is a randomised control trial;
Level III-1 is a pseudorandomised control trial;
Level III-2 is a comparative study with concurrent controls (includes non-randomised experimental trails and cohort studies);
Level III-3 is a comparative study without concurrent controls (includes historical control studies);
Level IV is a case-series with either post-test or pre-test/post-test outcomes. Previous research in related and other fields by Meulenbelt et al. [27] and Prange et al. [28] highlighted problems regarding the lack of NHMRC level I e III-1 trials (systematic randomisation to pseudorandomisation), which is also problematic in this area, therefore no restrictions were placed on the type of study included. Studies involving patients younger than 18 years of age were excluded. One reviewer (KB) initially screened all titles and abstracts of potentially eligible articles and full text articles were obtained and included for quality assessment. Four reviewers (KB, AH, CB & CM) independently rated the quality of included studies. They were divided into two reviewing teams (R1, R2) and each team reviewed half the studies. Full consensus was achieved for each study by discussion within each review team; if no consensus could be met, a third reviewer from the other team served as a moderator. Studies were evaluated using the Downs & Black critical appraisal tool [29] (mD&B) due to its reported objectivity and sensitivity [30]. This tool is a 27-item questionnaire appraising the reporting method of the study, internal and external validity

The PICO framework for inclusion of eligible articles. Criterion

Participants

Intervention








Comparison




Outcome







Unilateral or bilateral TTA or TFA Amputation due to trauma No limitation was placed on the gender or age of participants Type of sockets including quadrilateral socket (TFA) and ischial containment (TFA) and patellar-tendon bearing sockets (TTA) Studies investigating osseointegration were excluded as no socket is used in the suspension method The studies that were identified were compared in the context of the National Health and Medical Research Council (NHMRC) levels of evidence [26] and World Health Organization’s International Classification on Functioning, Disability and Health (WHO ICF) Skin/tissue viability Clinical outcome measures Biomechanical measurement Impact on quality of life

84

K. Butler et al.

and the study power. Permission was granted by Professor Eng (University of British Columbia, USA) to use the amended version developed by Eng et al. [31], in which a score was given to studies that had conducted a power or sample size calculation, or provided an explanation into the appropriateness of the sample size. Reviewers scored each question using a “Yes ¼ 1”, “No ¼ 0” and “Unable to determine ¼ 0” scoring system, enabling studies to be ranked by total score. The score thresholds suggested by Chudyk et al. [32] were used and only studies scoring 15 or greater were deemed of sufficient methodological quality to be included in the review. The type and level of research within the studies were further classified within the framework of the World Health Organisation’s International Classification of Functioning, Disability and Health (WHO ICF) (body functions & structure, activities, or participation) [33] and the NHMRC levels of evidence [26]. The following data were extracted from fulltext articles: study reference, number of participants, type of amputation (TTA or TFA), method, intervention where applicable, outcomes and key findings. One reviewer (KB) extracted data from included studies using a standardised proforma. Another reviewer (AH) independently crosschecked extracted data. Timescales for the studies, data collection points and methods of outcome measurement differed amongst the final included studies such that none were similar enough to allow any meta-analyses to be performed.

3. Results Electronic searches retrieved a total of 1224 citations. Of these, 153 were identified as potentially relevant. Supplementary searching of reference lists of those potentially eligible articles identified a further 102 potential articles. Following further criteria review, a total of 218 articles were submitted for quality assessment. Of these, 37 had mD&B scores of 15 or more, and were included in the review. Fig. 1 outlines the review process and presents results (including those papers rejected for review according to the inclusion/exclusion criteria) at each stage. Dashed boxes describe decision points where papers were included in the mD&B appraisal. The major characteristics of the included studies, mD&B scores, and categories according to the WHO ICF [33] and the NHMRC level of evidence [26] are summarised below. Five umbrella themes

Fig. 1 Flow diagram showing systematic literature search, including decision-making, stages of review and number of papers included at each stage.

emerged as descriptors for associated key factors related to tissue viability and lower limb prosthetic use from the final 37 articles. These key themes address the primary objective of the review. The themes were:
Prosthetic fit e skin breakdown following traumatic amputation is discussed within the factor. Methods of characterisation, outcome measures and clinical impact of interface materials, such as socks and liners, are reviewed.
The residuum e pressures, both compressive or shear, require measurement. The results showed that this factor provided limited information on prosthetic alignment and the influence alignment has on interface pressures over time.

Key factors affecting tissue viability and rehabilitation outcomes
Quality of life e a number of outcome measures are identified in this factor. Patient satisfaction was highlighted and reviewed in depth within this factor. The results highlight possible areas for further research of direct benefit to the patient.
Amputee care e diverse findings were covered within this factor, particularly focused on the socioeconomic considerations of amputations and amputee care following trauma.
Prosthetic use e assessment of walking/ running/sit-to-stand ability and physical mobility assessed by means of clinical outcome and biomechanical measures. The literature showed that this factor was also influenced by the choice of prosthetic components, level of amputation, energy expenditure and spatiotemporal parameters of amputee walking. These themes were derived from the focus and methodology of each paper and were defined by consensus of all four reviewers (KB, AH, CB & CM). The following section will review each of these themes in more detail.

85

The studies in this theme could be classified in the WHO ICF “Body Functions & Structure” and “Activities” categories, and as a combination of the two. All studies in this theme were similar in terms of level of evidence according to the NHMRC guidelines; III-2 [36,38], III-3 [34,35], IV [37]. These findings support the importance of regular clinical monitoring of patients who use lower extremity prostheses on a regular basis, to effectively manage the development of skin problems and maintenance of tissue viability of the stump interface. This is particularly important to those who are younger and have higher activity levels, such as servicemen and women who may not necessarily undergo routine tissue viability status checks of their residual limb(s). All investigators in this theme concluded that more prospective research was required within this field. The impact of quality research in this theme has a direct bearing on the effective clinical decision-making and is intrinsically related to the following two key themes. Following consensus among the reviewing team, this was identified as a central theme and could be influenced by, or influences all other themes.

3.1. Prosthetic fit 3.2. The residuum Five studies were identified in this theme. Issues related to fit of prostheses were linked to a high prevalence of skin problems and potentially higher levels of activity [34,35]. Additionally, delayed wound healing at the skin-stump site [36], physical properties of materials commonly used as supporting materials in prosthetics and orthotics [37] and microangiopathy [38] were all reported as leading to intolerance to the prosthesis. A total of 1832 amputees [35e37] and 8 liner materials [37] were investigated in this theme using both qualitative and quantitative methodological approaches. The results of this theme found that stump integrity, the amputee care regime and pain have an impact on the progression of participants’ ability to become mobile or remain mobile [36] (links also to the final key theme). Skin problems were notable factors identified in 40%e63% of participants as the most important reason that prevented effective use of the prosthesis [34,35]. Skin problems were reported to occur throughout the life cycle of the prosthesis [34] with higher activity levels and lower age being more likely predictors of this [34,35]. The most reported skin problems were pressure ulcers, infection hyperhidrosis and persistent heat rashes [34,35]. Others included irritation, inclusion cyst, callus, verrucous hyperplasia, blister, fungal infection, cellulitis, delayed postsurgical wound healing [34e36].

Three studies in this theme investigated factors that impact on, or topics relevant to, the residuum. This includes pressure measurement and the effects of socket alignment on resultant stump/socket interface pressures [12,13,39]. Studies within this theme were consistent in reporting complex diurnal and long-term fluctuations in interface pressures and shear stresses that may lead to residual limb tissue changes [12,13]. All studies report that pressure monitoring provides additional valuable information to the clinical assessment, however there was no consistent approach to measurement of the stumpesocket interface pressures [12,13,39,40]. Techniques included peak pressure and resultant shear stress measured by 13 discrete stress transducers embedded within the socket [12,13], vertical force measured by a force plate and force sensing resistor insoles placed between the prosthetic foot and shoe [40] and peak pressures, time of peak pressures and time-pressure integral measured by force sensing resistor strips placed within the socket [39]. The studies in this theme could be classified within the “Body Functions & Structure” [12,13,39] and “Activities” [40] of the WHO ICF, and achieved an NHMRC level of evidence between III-2 and IV. Studies reported good internal validity with

86 respect to bias, and were reported well, but had poor external validity and internal validity when considering confounding factors. This theme directly impacts the final theme (Prosthetic Use) and the information we can generate about the previous theme (Prosthetic Fit). By definition, the target population of servicemen and women is younger than the average amputee and are highly active; returning to sports and physical activities can become part of their rehabilitative goals. The activities undertaken by this population include sports, gym training and many more hours’ mobility than the largely sedentary dysvascular amputee population. Methods of quantifying the interface pressures over time particular to this population are paramount in understanding the demands placed on their prosthetic devices and sockets and the impact this has on tissue viability.

3.3. Quality of life Sixteen studies in this theme identified functional outcome measures [41e43], patient satisfaction [6,10,44e52], epidemiology of traumatic amputees [53], and aspects of patient health [54]. A total of 11,091 patients participated in the studies in this theme. The scope of some studies meant that minor amputations and upper limb amputations were also included [6,10,44,46,48,53], however this review focused only on the lower limb results presented in those papers. Three studies investigated different aspects of functional outcome measures [41e43] and indicated the measures used were sensitive enough to differentiate between through knee and other levels of amputation [41], duration from amputation [42] and cause of amputation [43]. The results of studies into satisfaction and use of prosthetic devices has shown that, while many patients were generally satisfied with their prosthetic device [44,45], there were a number of factors that affect prosthetic use and quality of life, such as, comfort, pain, skin breakdown of the residuum, level of amputation and presence of any co-morbidities typical amputation under service (post-traumatic stress disorder, depression and traumatic brain injury) [6,10,44,45,47,49e51]. The majority of the studies (n ¼ 12) could be classified as “Activities” and “Participation” in the WHO ICF framework [6,10,41,44e52]. Two studies were classified as “Activities” [42,43] and the remaining study was “Body Functions & Structure” and “Activities” [53]. Two studies achieved an NHMRC level of evidence of II [41,42], twelve

K. Butler et al. studies achieved a level of III-2 [6,10,43e49,52e54] and two studies were level III-3 [50,51].

3.4. Amputee care Three studies were included in this theme and all were retrospective. They included assessment of whether lower limb amputation was required following trauma [55], the prevalence of extremity injuries due to trauma in conflict [3] and the socioeconomic considerations associated with prosthetic devices following trauma in conflict [56]. Two studies were classified within the framework of the WHO ICF as “Body Functions & Structure” [3,55] and one was classified within the “Participation” category; more specifically covering the contextual factors of environmental and personal factors [56]. All achieved an NHMRC III-2 level of evidence. Retrospective data collection allowed large participant numbers to be achieved, resulting in all three studies having good external validity and well-justified sample sizes. The retrospective methods also meant that blinding and randomisation was impractical, resulting in a potential risk of poor internal validity. None of the studies investigated compliance. Trauma is particularly relevant to this population. A traumatic amputation will often lead to an irregular residuum and can be complicated by issues surrounding tissue viability, particularly being slow to heal. The shape of the residuum can also lead to areas of high pressure that are affected during activity, which can also impact skin breakdown. The results identified in this theme were particularly relevant to care pathways, rehabilitation procedures and the personal factors of amputees by illustrating the impact of socioeconomic considerations on amputee care. These important considerations will influence all other factors identified in this review.

3.5. Prosthetic use Nine studies investigated different aspects of prosthetic use associated with lower limb amputees, including the effects of different knee components on gait, investigating how the level of amputation changes energy expenditure during gait and the reliability of clinical outcome measures assessing mobility. A total of 86 participants (50 TFA and 36 TTA) were included in this theme. The studies in this theme were focussed toward the “Body Functions & Structure” [57,59e61], “Activities” [62,63] classification of the WHO ICF

Key factors affecting tissue viability and rehabilitation outcomes

Fig. 2 The distribution of studies within the NHMRC evidence level guidelines.

and a combination of these two categories [58,64,65]. The majority of studies in this theme achieved an evidence level of III-2, and one study achieved an NHMRC evidence level of III-1 due to randomised intervention [58]. Studies were well reported in this theme, with details regarding adverse events the only consistent omission. As previously stated, the majority of traumatic amputations have risen due to recent conflict and improvements in front-line defences. As a result, traumatic amputees are often from a younger and physically fit population. The metrics derived under the theme of ‘Prosthetic Use’ are therefore of paramount importance to improving clinical service provision and post-amputation rehabilitation because amputees from this population often want to maintain, where possible, participating in an active lifestyle longer term. In summary, tissue viability of the residual limb is inherently linked to intolerance of the prosthesis. For the primary objective, factors associated with this include complex high pressures over time at the stump socket interface, skin problems, younger age group and higher activity levels, all of which may be predictors of potential tissue breakdown. Evidence suggests that these factors, in turn, may lead to reduced mobility, lower

87

quality of life and affect rehabilitation postamputation, therefore addressing the secondary objective of this review. There is some limited evidence to suggest that pressure measurement as well as regular tissue viability assessments could be useful additions to the monitoring of these individuals, yet there is a general lack of reliable outcome measures to do this. Further prospective research was also recommended to investigate an integrated, multidisciplinary approach that encompasses the five identified key themes: prosthetic fit, the residuum, quality of life, amputee care and prosthetic use. 3.5.1. Methodological quality The majority of the studies (62%) were at a level III-2 of the NHMRC guidelines, suggesting that the majority of the literature is based on nonrandomised, cohort studies or caseecontrol studies [66] (see Fig. 2). A summary of studies according to the framework of the WHO ICF can be seen in Fig. 3. Eleven studies focussed on “Body Functions & Structure” aspects, 6 studies focussing on “Activities” and 6 studies that covered “Body Functions & Structure and Activities”. Twelve studies focused on “Activities” through to “Participation” and 2 studies highlighted issues of “Participation”. Table 2 provides a summary of the mD&B scores for each study. The emphasis in this field of research pertains to Quality of Life measures, with 16 studies included within that category. The residuum and amputee care factors appear to be the least well studied factors with 4 studies included in that theme. The evidence related to tissue viability is emergent with five studies included, although the evidence is low and relates to defining the problem of tissue viability, with an absence of higher level interventional studies.

Fig. 3 The distribution of studies according to the World Health Organisation’s International Classification of Functioning, Disability & Health.

88

K. Butler et al.

Table 2 A summary of the Downs & Black scores for each study (A ¼ reporting; B ¼ external validity; C ¼ internal validity e bias; D ¼ internal validity e confounding; E ¼ Power), including the NHMRC evidence hierarchy and the WHO ICF classification. Study theme

Downs & black item A (x/11)

Combined mean for all 37 studies [34] [35] [36] [37] [38] Mean [12] [13] [39] [40] Mean [6] [10] [50] [51] [52] [53] [54] [55] [56] [57] [58] [59] [60] [61] [62] [63] Mean [3] [64] [65] Mean [34] [35] [36] [37] [38] [39] [40] [41] [42] Mean

Prosthetic Fit

The Residuum

Quality of Life

Amputee Care

Prosthetic Use

B (x/3)

C (x/7)

D (x/6)

E (x/1)

Total (x/28)

8.16

2.01

3.83

2.13

0.85

16.53

8 8 9 10 7 8.4 8 10 9 9 9 8 8 9 9 8 8 8 7 8 8 7 6 8 7 8 7 7.75 6 7 8 7 10 9 10 9 9 7 8 7 9 8.67

3 2 3 1 2 2.2 0 1 2 0 0.75 3 2 3 2 3 3 3 3 3 2 3 3 2 3 3 3 2.75 3 2 3 2.67 2 1 1 2 3 2 1 1 2 1.67

3 2 4 4 4 3.4 5 5 4 4 4.5 3 4 5 5 5 3 3 3 3 3 3 3 3 2 3 3 3.38 3 3 4 3.33 5 5 5 4 3 4 5 5 5 4.56

2 3 4 1 2 2.4 2 2 0 2 1.5 1 1 3 1 0 2 2 2 2 2 2 2 2 2 2 2 1.75 2 3 2 2.33 2 3 2 2 2 4 3 2 4 2.67

0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 1 1 1 1 0 1 0 1 0 1 1 1 0.69 1 1 1 1 0 0 0 0 0 0 0 0 0 0

16 15 20 16 15 16.8 15 18 15 15 15.75 16 16 20 17 17 17 17 16 16 16 15 15 15 15 17 16 16.31 15 16 18 16.33 17 18 18 17 17 17 17 15 20 17.33

4. Discussion This review has identified, graded and synthesised the available literature to achieve the primary objective: to identify the key factors affecting tissue viability of the residual limb in lower

NHMRC

ICF

III-3 III-3 III-2 IV III-2 e IV III-3 III-3 III-3 e III-2 III-2 II II III-2 III-2 III-2 III-2 III-2 III-2 III-2 III-3 III-3 III-2 III-2 III-2 e III-2 III-2 III-2 e III-2 III-1 III-2 III-2 IV IV III-2 IV III-2 e

BFS/A A BFS/A BFS BFS e BFS BFS BFS A e A/P A/P A/P A A A/P A/P A/P A/P A/P A/P A/P A/P A/P BFS/A P e BFS BFS P e BFS BFS/A BFS BFS BFS A A BFS/A BFS/A e

extremity amputees. Five key themes were identified: prosthetic fit, the residuum, quality of life, amputee care and prosthetic fit; each umbrella theme covered factors associated with that theme. Evidence for improvements in skin health, prosthetic design, fit and measurement is

Key factors affecting tissue viability and rehabilitation outcomes emergent, yet results from this review indicate that the quality of this evidence remains low. Of the five key themes identified, all are influenced by or related to issues that affect rehabilitation post-amputation; the secondary objective of this review. When classified within the framework of the WHO ICF, the majority of studies focussed on the “Body Functions & Structure” or a combination of the “Activities” and “Participation” categories. This illustrates that a large proportion of the 37 studies investigated the “Participation” aspects as a subjective outcome combined with the “Activities” aspect as quantitative outcome measures when evaluating participant quality of life. The results, when viewed in the context of the NHMRC guidelines, show that the predominant level of evidence for the studies reviewed was III2. This shows that according to the National Health and Medical Research Council [66], the majority of the literature reviewed was based on nonrandomised, cohort studies or caseecontrol studies. Some investigators had attempted to address this (8.1%) such that the quality was rated higher at NHMRC level III-1 or II. The general results of the mD&B highlighted the need for improvements in the internal validity in study design, such as blinding of researchers, randomisation of participants and increasing the duration of the study from single-event to include a follow-up would lead to an increase in internal validity. This is inherently linked to the paucity of higher-level evidence in the NHMRC guidelines. The results of this review found only one (1/37) study that met the pre-determined methodological quality and randomised participants between interventions; specifically, the order in which transfemoral amputees walked with two different knee components [57]. Power calculations were conducted by 14/37 studies. Most studies quoted samples that were either convenience samples or case studies. However, the questionnaire-based studies tended to have greater sample numbers [3,35,55]. This was particularly evident in studies investigating effects of trauma, which included all the data available for their participant groups [3,55]. This was due primarily to the studies researching militaryrelated trauma, thus medical records for all participants were available to the authors.

4.1. Potential limitations Some items in the Downs & Black appraisal tool were open to subjectivity, although steps were

89

taken to address this, such as consensus discussions and third reviewer opinions. Therefore, the authors recommend multiple reviewing teams using this tool. It is also important to note that by the very nature of traumatic amputation, individual needs of the patient and the amputation are very different from each other. Therefore conventional analysis through study designs that would result in higher methodological quality under the NHMRC guidelines would arguably generate speculative results. The Authors acknowledge that the omission of the studies included specifically within the Cochrane Library may have limited the results of this review.

4.2. Implications for clinical practice There was a moderate evidence base for the studies appraised in this review. The key themes and factors associated with those illustrate the complex, integrated and multidisciplinary approach required of amputee care. Further investigation for implementation of patient education strategies is recommended as a priority, particularly regarding predictive and protective strategies that can influence self-care and general health. It is imperative that clinical resources are targeted in these areas. More globally, costs are predicted to rise for the provision of prosthetic and assistive devices for conflict-associated traumatic amputees due to greater use, a predominately young, fit population, and more technologically advanced devices. Therefore, a need was identified to provide more choices regarding prosthetic devices and keeping patients informed of prosthetic device development [10]. These results will influence clinical management strategies to prevent tissue breakdown.

4.3. Implications for research From the research perspective, five descriptive key themes pertaining to lower limb tissue viability of the residual limb in lower extremity amputees were identified that had moderate levels of evidence. Low internal validity, fixed assessment protocols and lack of blinding and randomisation, affected the overall quality of research in this field. This made comparisons difficult and highlighted the need for standardisation within assessment protocols and adopted outcome measures. In comparison to other work related to tissue viability in long term conditions, the results of

90 this review showed there is a paucity of research in “prosthetic fit”, “the residuum” and “amputee care”; three key factors that are particularly relevant under the objective of this review. In this target population, where irregular stump shape, increased stump volume with time and prolonged healing due to trauma can contribute or exacerbate areas of high stress, more rigorous measurement would improve care pathways and quality of life. In addition, further work on basic science and associated technology involving wound care, liners and socks, etc., to continuously monitor tissue viability is also paramount for improving clinical management strategies and patient wellbeing.

5. Conclusion The results of this review highlight that the field of tissue viability related to prosthetic research is still relatively new and emerging, with a wide variety of research being conducted to develop and inform health professionals and patients. This will further our understanding of the key factors affecting tissue viability of the residual limb in lower limb prosthetic use. Five key themes were identified relating to tissue viability and lower limb prosthetic use: prosthetic fit, the residuum, quality of life, amputee care and prosthetic use. All five themes were shown to influence rehabilitation post-amputation. However, the results indicate that the methodological quality within research study designs is low. Given the recently influx of service personnel and others in the population with acquired traumatic amputations, we anticipate that this will improve over time. From this review we have identified areas of clinical practice and clinical research that could be further developed to improve prognosis for tissue viability of the residual limb in lower extremity amputees. Further research is recommended to provide robust evidence that will inform future prosthetic prescription, management of stump tissue viability, care pathways and overall quality of life if the particular needs of this young, fit and highly active population are to be tailored to achieve their full potential.

Funding This work was supported by the Ministry of Defence: Centre for Defence and Enterprise [Ref: CDE12813].

K. Butler et al.

Conflicts of interest The Authors report no conflict of interest.

Appendix A. Full literature search strategy and the number of articles sourced from each database.

Search number

Search term

1

Motion analysis AND transfemoral amputees OR transtibial amputees OR lower limb amputees OR above-knee amputees OR below-knee amputees Stump socket interface AND transfemoral amputees OR transtibial amputees OR lower limb amputees OR above-knee amputees OR below-knee amputees Pressure AND transfemoral amputees OR transtibial amputees OR lower limb amputees OR above-knee amputees OR below-knee amputees Pressure AND sock/stump interface OR socket stump interface Pressure AND transfemoral amputees OR transtibial amputees AND biomechanical OR contributing AND factors Pressure AND measurement AND transfemoral amputees OR transtibial amputees OR lower limb amputees OR above-knee amputees OR below-knee amputees Pressure AND socket stump interface OR sock stump interface AND measurement

2

3

4

5

6

7

Total number of studies (not including duplicates) 60

17

163

34

0

23

10

(continued on next page)

Key factors affecting tissue viability and rehabilitation outcomes (continued ) Search number

Search term

8

EMG AND transfemoral amputees OR transtibial amputees OR lower limb amputees OR above-knee amputees OR below-knee amputees Force AND transfemoral amputees OR transtibial amputees OR lower limb amputees OR above-knee amputees OR below-knee amputees Stump integrity AND transfemoral amputees OR transtibial amputees OR lower limb amputees OR above-knee amputees OR below-knee amputees Skin problems OR skin integrity AND transfemoral amputees OR transtibial amputees OR lower limb amputees OR above-knee amputees OR below-knee amputees Transfemoral socket OR transtibial socket Trauma AND transfemoral amputees OR lower limb amputees OR above-knee amputees OR transtibial amputee (RECAL only) Military AND trauma AND lower limb OR lower extremity Transfemoral OR transtibial AND pressure

9

10

11

12 13

14

15

Total number of studies (not including duplicates) 30

199

12

82 216

113

265 1224

References [1] National Amputee Statistical Database. The amputee statistical database for the United Kingdom 2006/07. Scotland: Information Services Division NHS; 2005. [2] Dumbleton T, Buis AW, McFadyen A, McHugh BF, McKay G, Murray KD, et al. Dynamic interface pressure distributions of two transtibial prosthetic socket concepts. J Rehabil Res Dev 2009;46(3):405e15.

91

[3] Dougherty AL, Mohrle CR, Galarneau MR, Woodruff SI, Dye JL, Quinn KH. Battlefield extremity injuries in Operation Iraqi Freedom. Inj Int J Care Inj 2009;40(7):772e7. [4] Stansbury LG, Branstetter JG, Lalliss SJ. Amputation in military trauma surgery. J Trauma Inj Infect Critical Care 2007;63(4):940e4. [5] Stewart JD, Anderson CD, Unger DV. The Portsmouth modification of the Ertl bone-bridge transtibial amputation: the challenge of returning amputees back to active duty. Oper Tech Sports Med 2005;13(4):222e6. [6] Epstein RA, Heinemann AW, McFarland LV. Quality of life for veterans and servicemembers with major traumatic limb loss from Vietnam and OIF/OEF conflicts. J Rehabil R D 2010;47(4):373e86. [7] Herritty H, Hudson M, Letts M. Health, welfare and social needs of the Armed Forces Community: a qualitative study. The British Legion; 2011. [8] The Royal British Legion. Centre for future Studies. Legion welfare in the 2010s: a decade of change; 2011. [9] Silver-Thorn MB, Steege JW, Childress DS. A review of prosthetic interface stress investigations. J Rehabil Res Dev 1996;33(3):253e66. [10] Berke GM, Fergason J, Milani JR, Hattingh J, McDowell M, Nguyen V, et al. Comparison of satisfaction with current prosthetic care in veteransf n and servicemembers from Vietnam and OIF/OEF conflicts with major traumatic limb loss. J Rehabil Res Dev 2010;47(4):361e72. [11] Beil TL, Street GM. Comparison of interface pressures with pin and suction suspension systems. J Rehabil Res Dev 2010;41(6A):821e8. [12] Sanders JE, Bell DM, Okumura RM, Dralle AJ. Effects of alignment changes on stance phase pressures and shear stresses on transtibial amputees: measurements from 13 transducer sites. IEEE Trans Rehabil Eng 1998;6(1):21e31. [13] Sanders JE, Zachariah SG, Jacobsen AK, Fergason JR. Changes in interface pressures and shear stresses over time on trans-tibial amputee subjects ambulating with prosthetic limbs: comparison of diurnal and six-month differences. J Biomech 2005;38(8):1566e73. [14] Sanders JE, Goldstein BS, Leotta DF. Skin response to mechanical stress: adaptation rather than breakdown - a review of the literature. J Rehabil Res Dev 1995;32(3):214e26. [15] Chou YL, Shi SS, Huang GF, Lin TS. Interface pressure and gait analysis in different walking speeds and on the below-knee amputees with multiple axis prosthetic foot prosthesis. Biomed Eng Appl Basis Commun 2003;15(5): 207e11. [16] Klute GK, Glaister BC, Berge JS. Prosthetic liners for lower limb amputees: a review of the literature. Prosthet Orthot Int 2010;34(2):146e53. [17] Lyon CC, Kulkarni J, Zimerson E, Van Ross E, Beck MH. Skin disorders in amputees. J Am Acad Dermatol 2000; 42(3):501e7. [18] Polliack AA, Sieh RC, Craig DD, Landsberger S, McNeil DR, Ayyappa E. Scientific validation of two commercial pressure sensor systems for prosthetic socket fit. Prosthet Orthot Int 2000;24(1):63e73. [19] Sanders J. Interface mechanics in external prosthetics: review of interface stress measurement techniques. Med Biol Eng Comput 1995;33(4):509e16. [20] Sanders JE, Daly CH, Burgess EM. Clinical measurement of normal and shear stresses on a trans-tibial stump: characteristics of wave-form shapes during walking. Prosthet Orthot Int 1993;17(1):38e48. [21] Lee WCC, Zhang M. Using computational simulation to aid in the prediction of socket fit: a preliminary study. Med Eng Phys 2007;29(8):923e9.

92 [22] Mak AF, Zhang M, Boone DA. State-of-the-art research in lower-limb prosthetic biomechanics socket interface: a review. J Rehabil R D 2001;38(2):161e74. [23] Naeff M, van Pijkeren T. Dynamic pressure measurements at the interface between residual limb and socket - the relationship between pressure distribution, Comfort, and Brim shape. Bull Prosthet Res 1980;17(1):35e50. [24] Huang X, Lin J, Demner-Fushman D. Evaluation of PICO as a knowledge representation for clinical questions. AMIA Annu Symp Proc 2006:359e63. [25] Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. Br Med J 2009;339:b2700. [26] National Health and Medical Research Council. NHMRC levels of evidence and grades for recommendations for developers of guidelines; 2009. p. 1e24. www.nhmrc.gov.au. [27] Meulenbelt H, Dijkstra P, Jonkman M, Geertzen J. Skin problems in lower limb amputees: a systematic review. Disabil Rehabil 2006;28(10):603e8. [28] Prange GB, Jannink MJA, Groothuis-Oudshoorn CGM, Hermens HJ, Ijzerman MJ. Systematic review of the effect of robot-aided therapy on recovery of the hemiparetic arm after stroke. J Rehabil Res Dev 2006;43(2): 171e84. [29] Downs SH, Black N. The feasibility of creating a checklist for the assessment of the methodological quality both of randomised and non-randomised studies of health care interventions. J Epidemiol Community Health 1998;52(6): 377e84. [30] Deeks JJ, Dinnes J, D’Amico R, Sowden AJ, Sakarovitch C, Song F, et al. Evaluating non-randomised intervention studies. Health Technol Assess 2003;7(27):1e192. [31] Eng JJ, Teasell RW, Miller WC, Wolfe DL, Townson AF, Aubut JA, et al. Spinal cord injury rehabilitation evidence: method of the SCIRE systematic review. Top Spinal Cord Inj Rehabil 2007;13(1):1e10. [32] Chudyk AM, Jutai JW, Petrella RJ, Speechley M. Systematic review of hip Fracture rehabilitation practices in the Elderly. Arch Phys Med Rehabil 2009;90(2):246e62. [33] World Health Organisation. Toward a common language for functioning, disability and Health: ICF Beginners Guide; 2002. p. 1e23. [34] Dudek NL, Marks MB, Marshall SC, Chardon JP. Dermatologic conditions associated with use of a lowerextremity prosthesis. Arch Phys Med Rehabil 2005;86(4): 659e63. [35] Meulenbelt HE, Geertzen JH, Jonkman MF, Dijkstra PU. Determinants of skin problems of the stump in lower-limb amputees. Arch Phys Med Rehabil 2009;90(1):74e81. [36] Chakrabarty BK. An audit of the quality of the stump and its relation to rehabilitation in lower limb amputees. Prosthet Orthot Int 1998;22(2):136e46. [37] Sanders JE, Greve JM, Mitchell SB, Zachariah SG. Material properties of commonly-used interface materials and their static coefficients of friction with skin and socks. J Rehabil Res Dev 1998;35(2):161e76. [38] Macchi C, Cassigoli S, Molino LR, Roccuzzo A, Miniati B, Ceppatelli S, et al. Prosthesis intolerance in patients with transfemoral amputation: a Videocapillaroscopic study. Am J Phys Med Rehabil 2004;83(6):486e91. [39] Seelen H, Anemaat S, Janssen H, Deckers J. Effects of prosthesis alignment on pressure distribution at the stump/socket interface in transtibial amputees during unsupported stance and gait. Clin Rehabil 2003;17(7): 787e96.

K. Butler et al. [40] Luo G, Houston V, Sasson N, Garbarini M, Beattie A. Gait characteristic indices to quantitatively characterize human gait. J Prosthet Orthot 2011;23(3):108e13. [41] MacKenzie EJ, Bosse MJ, Castillo RC, Smith DG, Webb LX, Kellam JF, et al. Functional outcomes following traumarelated lower-extremity amputation. J Bone Jt Surg Am 2004;86(8):1636e45. [42] Panesar BS, Morrison P, Hunter J. A comparison of three measures of progress in early lower limb amputee rehabilitation. Clin Rehabil 2001;15(2):157e71. [43] Miller WC, Deathe AB, Speechley M. Psychometric properties of the activities-specific balance confidence scale among individuals with a lower-limb amputation. Arch Phys Med Rehabil 2003;84(5):656e61. [44] Pezzin LE, Dillingham TR, MacKenzie EJ, Ephraim P, Rossbach P. Use and satisfaction with prosthetic limb devices and related services. Arch Phys Med Rehabil 2004; 85(5):723e9. [45] Gailey R, McFarland LV, Cooper RA, Czerniecki J, Gambel JM, Hubbard S, et al. Unilateral lower-limb loss: prosthetic device use and functional outcomes in service members from Vietnam war and OIF/OEF conflicts. J Rehabil Res Dev 2010;47(4):317e32. [46] Reiber GE, McFarland LV, Hubbard S, Maynard C, Blough DK, Gambel JM, et al. Service members and veterans with major traumatic limb loss from Vietnam war and OIF/OEF conflicts: survey methods, participants, and summary findings. J Rehabil Res Dev 2010;47(4):275e98. [47] Matsen SL, Malchow D, Matsen III FA. Correlations with patients’ perspectives of the result of lower-extremity amputation. J Bone Jt Surg Am 2000;82(8):1089e95. [48] Dougherty PJ, McFarland LV, Smith DG, Esquenazi A, Blake DJ, Reiber GE. Multiple traumatic limb loss: a comparison of Vietnam veterans to OIF/OEF servicemembers. J Rehabil Res Dev 2010;47(4):333e48. [49] Legro MW, Reiber G, del Aguila M, Ajax MJ, Boone DA, Larsen JA, et al. Issues of importance reported by persons with lower limb amputations and prostheses. J Rehabil Res Dev 1999;36(3):155e63. [50] Gauthier-Gagnon C, Grise MC, Potvin D. Predisposing factors related to prosthetic use by people with a transtibial and transfemoral amputation. J Prosthet Orthot 1998;10(4):99e109. [51] Gauthier-Gagnon C, Gris MC, Potvin D. Enabling factors related to prosthetic use by people with transtibial and transfemoral amputation. Arch Phys Med Rehabil 1999; 80(6):706e13. [52] Dillingham TR, Pezzin LE, MacKenzie EJ, Burgess A. Use and satisfaction with prosthetic devices among persons with trauma-related amputations: a long-term outcome study. Am J Phys Med Rehabil 2001;80(8):563e71. [53] Dillingham TR, Pezzin LE, MacKenzie EJ. Incidence, acute care length of stay, and discharge to rehabilitation of traumatic amputee patients: an epidemiologic study. Arch Phys Med Rehabil 1998;79(3):279e87. [54] Pezzin LE, Dillingham TR, MacKenzie EJ. Rehabilitation and the long-term outcomes of persons with traumarelated amputations. Arch Phys Med Rehabil 2000;82(8): 292e300. [55] Brown KV, Ramasamy A, McLeod J, Stapley S, Clasper JC. Predicting the need for early amputation in ballistic mangled extremity injuries. J Trauma, Inj Infect Critical Care 2009;66(4):S93e8. [56] Blough DK, Hubbard S, McFarland LV, Smith DG, Gambel JM, Reiber GE. Prosthetic cost projections for service members with major limb loss from Vietnam and OIF/OEF. J Rehabil Res Dev 2010;47(4):387e402.

Key factors affecting tissue viability and rehabilitation outcomes [57] Sjodahl C, Jarnlo GB, Soderberg B, Persson BM. Kinematic and kinetic gait analysis in the sagittal plane of transfemoral amputees before and after special gait re-education. Prosthet Orthot Int 2002;26(2):101e12. [58] Boonstra AM, Schrama JM, Eisma WH, Hof AL, Fidler V. Gait analysis of transfemoral amputee patients using prostheses with two different knee joints. Arch Phys Med Rehabil 1996;77(5):515e20. [59] Sjodahl C, Jarnlo GB, Soderberg B, Persson BM. Pelvic motion in trans-femoral amputees in the frontal and transverse plane before and after special gait re-education. Prosthet Orthot Int 2003;27(3):227e37. [60] Genin J, Bastien G, Franck B, Detrembleur C, Willems P. Effect of speed on the energy cost of walking in unilateral traumatic lower limb amputees. Eur J Appl Physiol 2008; 103(6):655e63. [61] Nadollek H, Brauer S, Isles R. Outcomes after trans-tibial amputation: the relationship between quiet stance ability, strength of hip abductor muscles and gait. Physiother Res Int 2002;7(4):203e14.

93

[62] Gauthier-Gagnon C, Gravel D, St-Amand H, Murie C, Goyette M. Changes in ground reaction forces during prosthetic training of people with transfemoral amputations: a pilot study. J Prosthet Orthot 2000;12(3):72e6. [63] Schoppen T, Boonstra A, Groothoff JW, de Vries J, GOeken LNH, Eisma WH. The timed “up and go” test: reliability and validity in persons with unilateral lower limb amputation. Arch Phys Med Rehabil 1999;80(7): 825e8. [64] Sjodahl C, Jarnlo GB, Persson BM. Gait improvement in unilateral transfemoral amputees by a combined psychological and physiotherapeutic treatment. J Rehabil Med 2001;33(3):114e8. [65] Taheri A, Karimi MT. Evaluation of the gait performance of above-knee amputees while walking with 3R20 and 3R15 knee joints. J Res Med Sci 2012;17(3):258e63. [66] National Health and Medical Research Council. How to use the evidence: assessment and application of scientific evidence. National Health and Medical Research Council; 2000. Report No.: CP69.