The Knud Jansen lecture. Technological choices in prosthetics and orthotics for developing countries

Rehabilitation in Low-Resource Areas

Earlier rehabilitation interventions, like community-based rehabilitation (CBR), could not make a remarkable impact because they ran parallel to the health system, but the newer model establishes health-related rehabilitation as an integral part of the health care system at all levels and thus should be implemented as such. Collaborating with other players relevant to the CBR matrix, such as social and vocational services, can be imparted for the empowerment of a disabled group at the village level through the CBR center. A multipurpose rehabilitation worker, through skill transfer or task shifting, can start rehabilitation at the primary health center.

A New Functional Scale and Ambulatory Functional Classification of Duchenne Muscular Dystrophy: Scale Development and Preliminary Analyses of Reliability and Validity

Objective

To develop a simplified functional scale and classification system to evaluate the functional abilities of patients with Duchenne muscular dystrophy (DMD).

Methods

A Comprehensive Functional Scale for DMD (CFSD) was developed using the modified Delphi method. The accompanying Ambulatory Functional Classification System for DMD (AFCSD) was developed based on previously published classification systems.

Results

The CFSD consists of 21 items and 78 sub-items, assessing body structure and function, activities, and participation. Inter-rater intraclass correlation coefficient values were above 0.7 for 17 items. The overall limits of agreement between the two examiners ranged from -6.21 to 3.11. The Spearman correlation coefficient between the total score on the AFCSD and the Vignos Functional Scale was 0.833, and 0.714 between the total score of the AFCSD and the Brooke scale. Significant negative correlations existed between the total score for each functional level of the AFCSD and each functional grade of the Vignos and Brooke scales. The total scores of the CFSD varied significantly between the functional grades of the Vignos scale, and specific grades of the Brooke scale. For the AFCSD, total scores of the CFSD varied significantly between the functional levels.

Conclusion

We have developed a new scale and the associated classification system, to assess the functional ability of children diagnosed with DMD. Preliminary evaluation of the psychometric properties of the functional scale and classification systems indicate sufficient reliability and concurrent validity.

Transtibial Prosthetic Socket Shape in a Developing Country: A study to compare initial outcomes in Pressure Cast hydrostatic and Patella Tendon Bearing designs

This study compared the physical function and comfort level of patients with unilateral transtibial amputation after being fitted with a hand-cast Patella Tendon Bearing (PTB) socket and a pressure-cast (PCAST) hydrocast socket. The latter technique aims to reduce the skill dependency currently required for socket manufacture and fit. The study was conducted at the Vietnamese Training Centre for Orthopaedic Technologies and involved seventeen Vietnamese participants with unilateral transtibial amputation, all of whom were long term users of prosthetics. All participants were fitted with two sockets manufactured using both hand-cast and PCAST techniques with International Committee of the Red Cross components. Walking tests (timed up and go test and six-minute-walk-test), spatio-temporal gait analyses and subjective comfort assessments were completed after a short acclimatisation period with each socket. The participant-preferred socket was also noted. No significant differences were found for the measures of mobility, functional capacity, spatio-temporal gait parameters, gait symmetry, perceived comfort or participant socket preference. The results show the initial patient outcomes are similar when participants are fitted with a hand-cast PTB socket and a PCAST hydrocast sockets. Future work should confirm these findings in a longer trial.

Polio revisited: reviving knowledge and skills to meet the challenge of resurgence

PURPOSE

To date, polio has not been eradicated and there appears to be a resurgence of the disease. Hence, there is a need to revive decision-making skills to treat the effects of polio.

METHODS

Here, we outline the aspects of treatment of paralysis following polio based on the literature and personal experience of the authors. The surgical treatment of the lower and upper extremities and the spine have been reviewed. The scope of bracing of the lower limb has been defined.

RESULTS

The effects of polio can be mitigated by judicious correction of deformities, restoration of muscle balance, stabilising unstable joints and compensating for limb length inequality.

CONCLUSIONS

As polio has not been eradicated and there is a risk of resurgence of the disease, paediatric orthopaedic surgeons need to be prepared to deal with fresh cases of polio. Revival of old techniques for managing the effects of paralysis following polio is needed.

Clinical field follow-up of high density polyethylene (HDPE)-Jaipur prosthetic technology for trans-tibial amputees

The purpose of this study was to examine the outcome of the application of the High Density Polyethylene (HDPE)-Jaipur prosthetic construction in fitting trans-tibial amputees in a number of projects in the developing world. Projects in Honduras, Uganda and India were visited. Three hundred and twenty (320) patients had been provided with a HDPE-Jaipur prosthesis and of these 172 were seen for a technical and clinical follow-up after a median of 35 months. More than half the amputations were due to trauma, the remainder to disease. Fabrication and fitting in the three projects was carried out by individuals who had undertaken a twice week training course provided by Bhagwan Mahaveer Viklang Sahayata Samiti limb centre in Jaipur. The individuals involved had limited background training in prosthetics. Craftsmanship and fit were assessed as being poor in 56% of cases. The technical quality of the Jaipur foot was considered acceptable as its performance was better than previously observed results. Although there was patient satisfaction of 85% and compliance of 94% the HDPE-Jaipur trans-tibial system was not considered acceptable as 49% reported walking distances less than 1km and 36% discomfort. The major inadequacy in outcome relates to the use for fabrication and fitting of individuals with inadequate education and training.

Clinical field follow-up of high density polyethylene (HDPE)-Jaipur prosthetic technology for trans-femoral amputees

The purpose of this study was to examine the outcome of the application of the high density polyethylene (HDPE)-Jaipur prosthetic construction in fitting trans-femoral amputees in a number of projects throughout the developing world. Projects in Honduras, Uganda and India were included. One hundred and fifty eight (158) patients had been provided with the HDPE-Jaipur prosthesis and of these 72 were seen for a clinical and technical follow-up after a median of 32 months. More than half the amputees seen had amputation due to trauma and the remainder due to disease. Fabrication and fitting in the three projects was carried out by individuals who had undertaken a three week training course provided by Bhagwan Mahaveer Viklang Sahayata Samiti limb centre in Jaipur. The individuals involved had limited background training in prosthetics. Craftsmanship and fit were assessed as being poor in 86% of cases. Failure requiring replacement of components was observed in 50% of cases. There was low patient satisfaction (58%) and patient compliance (65%). The outcome was considered unsatisfactory both technically and clinically. This was a reflection of the inadequacies of the prosthetic construction, particularly the knee joint, and the inadequate training of those involved in fitting and fabrication of the devices.

Characterisation of prosthetic feet used in low-income countries

Eleven kinds of prosthetic feet that were designed for use in low-income countries were mechanically characterised in this study. Masses of the different kinds of prosthetic feet varied substantially. Dynamic properties, including damping ratios and resonant frequencies, were obtained from step unloading tests of the feet while interacting with masses comparable to the human body. Data showed that for walking, the feet can be appropriately modeled using their quasistatic properties since natural frequencies were high compared to walking frequencies and since damping ratios were small. Roll-over shapes, the effective rocker (cam) geometries that the feet deform to under walking loads, were determined using a quasistatic loading technique and a spatial transformation of the ground reaction force's centre of pressure. The roll-over shapes for most of the prosthetic feet studied were similar to the roll-over shape of the SACH (solid-ankle cushioned heel) prosthetic foot. All roll-over shapes showed a lack of forefoot support, which may cause a "drop-off" experience at the end of single limb stance and shorter step lengths of the contralateral limb. The roll-over shapes of prosthetic feet appear useful in characterization of foot function.

Activities of daily living in non-Western cultures: range of motion requirements for hip and knee joint implants

The purpose of this review of the literature was to investigate the functional range of motion requirements of non-Western populations in respect to artificial hip and knee joint implants. It was discovered that in Asia and the Middle East many activities are performed while squatting, kneeling, or sitting cross-legged. These positions demand a greater range of motion than that typically required in Western populations. For example, authors report that to squat one requires 130 degrees-full hip flexion and 111 degrees-165 degrees (or full) knee flexion. To sit cross-legged one requires 90 degrees-100 degrees hip flexion and 111 degrees-165 degrees (or full) knee flexion. This study identified a lack of documented research in this area, and the research that has been done provided inconsistent data. Potential reasons for discrepancies in the data are discussed, including the use of different methods to collect range of motion measurements, unclear use of terminology, and variations in normal passive and active range. In conclusion, this study stresses the importance of culture and function in the design and use of any new joint or product.

An "appropriate technology" trans-femoral prosthesis, using materials available in Nepal

The use of western components and materials for prostheses is prohibitively expensive in most developing countries. In addition, local customs and conditions vary considerably from those for which the prostheses were designed. For these reasons, a trans-femoral prosthesis has been developed in Pokhara, Nepal, using entirely locally available materials, and with a view to fulfilling local requirements as far as possible. This paper describes the materials and fabrication technique for the component parts of the prosthesis, the local conditions for which it was developed, and a three year follow-up of the first prosthesis issued. Only one serious design fault was discovered during this period, and a modification to the fabrication procedure introduced. The authors believe that if this trend continues, this style of prosthesis may be useful in the future for Nepali amputees and perhaps also in other countries, particularly where mass production of components is not practical.

Different approaches and cultural considerations in third world prosthetics

The major objective of prosthetics the world over is the same, i.e. to restore the amputee to as functional a capacity as possible in his cultural environment, whilst attaining as good a cosmetic result as can be achieved. At first glance it would seem that this would mean there would be very little difference in approach to the subject in western and in third world countries. Availability of materials, resources and skilled personnel, together with a variety of cultural differences, however, make third world prosthetics a subject in itself. This paper reviews the literature available on the subject, examines some different approaches to prosthetics in the third world, gives an overview of some materials and designs used and considers adaptations for cultural differences. It concludes that, whilst direct transfer of western prosthetics technology is useful in the short term, for long term benefit to the poorer amputees in the third world, culture-specific designs and materials are more appropriate.

The Jaipur limb and foot

In the 12 years which have elapsed since the United Nations declared 1981 to be the Year of the Disabled, the number of amputees world-wide has risen alarmingly, continuing the pattern of the past 40 years, which have seen innumerable conflicts, large and small, with ever-increasing and indiscriminate use of 'improved' antipersonnel mines which have been sown in enormous numbers in rural areas. Even after fighting has ceased--as in Vietnam, which currently has some 200,000 amputees--fresh injuries are caused daily, often to children, by the long-delayed detonation of these weapons. Much of the research and development in prosthetics since World War II has concentrated on producing artificial limbs suitable for an affluent and industrialized society. These, being made from the most modern materials and incorporating the latest technology, are of necessity expensive even for affluent Americans or Europeans and quite out of reach for the 80 per cent of the world's amputees who live in the developing world and for the vast majority of whom these splendid prostheses may be entirely inappropriate. This article describes a foot and leg specifically designed to fit in with the customs and practices of just such people.