The effectiveness of total surface bearing compared to specific surface bearing prosthetic socket design on health outcomes of adults with a trans-tibial amputation: a systematic review

Background Lower-limb prostheses enable life participation for people with amputation. The aim of this systematic review was to synthesize evidence on the effectiveness of total surface bearing (TSB) compared with specific surface bearing (SSB) prosthesis designs on health outcomes. Inclusion criteria Types of participants Trans-tibial amputees aged 14 years and older, irrespective of etiology, gender or co-morbidities, utilizing a TSB or SSB prosthesis. Types of interventions and comparators The intervention was the TSB socket and the comparator was the SSB socket. Types of studies This review considered all relevant quantitative study designs for inclusion. Outcomes and outcome measures Outcome measures relating to function and mobility, comfort and pain, quality of life and energy expenditure were considered. Search strategy A three-step search strategy across 13 databases and discipline-specific resource sites was pursued. Published and unpublished studies in English were considered, from database inception to June 2012. Methodological quality Two independent reviewers, using the Joanna Briggs Institute MAStARI appraisal checklists, undertook critical appraisal. Data collection Data was extracted using the MAStARI tool from the Joanna Briggs Institute. The data included details about interventions, populations, study methods and outcomes of significance to the review. Data synthesis Quantitative data was pooled in statistical meta-analysis using the Cochrane Review Manager Version 5.2, where possible. Where not possible, findings were presented using narrative and tables. Results This review identified and analyzed 28 outcome measures assessing the domains included in the review. They presented mixed findings. Twenty-one measures found no difference between the socket designs; four found a significant difference favoring the TSB design and three found a significant difference favoring the SSB design. Variation was found in the suspension and interface used in the socket designs. Sub-group analysis assessed TSB with gel interface and SSB with foam interface, to examine whether interface influenced outcomes. Four measures found no difference and two measures, being walking speed and cadence, found a significant difference favoring the TSB design. Sub-groups were further analyzed to assess the influence of distal suspension with TSB compared to supra-condylar suspension utilized with SSB. A significant difference in effect favoring the TSB design was identified for walking speed and socket preference outcomes. Conclusions The available evidence on the effectiveness of the alternative socket designs suggests that there is no clear choice between the TSB and SSB prosthetic socket designs. This may be due to variation in the interface and suspension utilized. Interpreting the results of the meta-analysis and non-pooled studies, the TSB design was as effective as the SSB design in improving health outcomes relating to function, comfort and quality of life. Implications for practice The review finding, that the TSB design is as effective as the SSB socket design in improving health outcomes implies that prescription consideration may depend on prescriber knowledge, prosthetist skill-set, funding availability and patient preference. Prosthetists should have the skill-set to deliver the TSB design. TSB prescription involves a gel interface, which can incur an additional cost; therefore funding bodies should begin to make provisions for use of gel interface with TSB design. Implications for research Additional high quality studies involving a larger sample of participants of all etiologies are required. Consistency in socket elements and measures is critical to facilitate comparison across studies and enhance the robustness of meta-analysis in future research. Studies on the cost effectiveness of socket design types are required to provide knowledge about the most efficient choice from a societal perspective.