Ossur Scientific E-letter
3 June 2008
Ossur Academy’s scientific E-letter Issue #2 2008
| Index |
Dear readers,
Welcome to the second issue of our Scientific E-letter of 2008. We are happy to share pertinent and interesting scientific news with you! This E-letter includes ten different scientific papers. The articles cover the subjects of amputation/rehabilitation, prosthetics/biomechanics, orthotics/biomechanics, bionics and quality management. Seven of the selected papers have been published in 2008 and three in 2007.
Enjoy the reading!
Amputation/Rehabilitation
Papazafiropouloua A. Tentolourisa N. Soldatosa RP. Liapisb CD. Dounisc E. Kostakisb AG. Bastounisd E. Katsilambrosa N.
Mortality in diabetic and nondiabetic patients after amputations performed from 1996 to 2005 in a tertiary hospital population: a 3-year follow-up study
It is well known that diabetes is the leading cause of lower-extremity amputations and studies have shown that mortality and re-amputation rates are increased in both diabetic and non-diabetic amputees.
Papazafiropouloua and collegues performed a retrospective study of the survival after first amputation between subjects with and without diabetes in a sample of Greek population. Amputations, excluding those related to trauma or neoplasm, between the years of 1996 and 2005 were included. The number of diabetic amputees was 183 and non-diabetic amputees was 75. Survival status was assessed from the first amputation up to December 31, 2005.
The study group found that 54.6% of amputees with diabetes and 51.6% of those without diabetes respectively died in a mean time of 4.3 and 6.6 years after the first amputation. Diabetic patients underwent a second amputation and contralateral amputations more often in comparison with nondiabetic subjects. Median length of hospital stay was comparable between the two groups.
The conclusion was that mortality rate was high in amputees both with and without diabetes. Higher level of amputation and older age were connected to decreased survival. Furthermore, diabetic patients more often underwent a second amputation to the same and the contralateral limb in comparison to non diabetic amputees.
Smurr LM. Gulick K. Yancosek MK. Ganz O.
Managing the Upper Extremity Amputee: A Protocol for SuccessJ HAND THER. 2008;21:160–76.
Since 2001 over 541 combat wounded individuals with major limb amputations have been seen in the US Military Healthcare System.
Smurr and colleagues developed a five phase upper extremity protocol to structure and accommodate the requirements of clients with upper extremity limb loss. The treatment program is based on the needs of the patients and the experience and collective expertise of the authors. The five phases of the protocol include acute management; preprosthetic training; basic prosthetic training; advanced prosthetic training and discharge planning.
- Phase 1 addresses acute management and wound healing.
Phase 2 marks the introduction of preprosthetic training.
Phase 3 embarks on prosthetic training.
Phase 4 focuses on advanced functional training.
Phase 5 involves discharge planning.
The phases might overlap to allow flexibility of client progression based on severity of injuries, wound healing, and client tolerance. Throughout each phase care is individualized to meet the needs of each patient. Occupation-based goals are established when the patient is medically stable. The rehabilitation goal for the upper limb military amputee is the provision of necessary skills and tools required to achieve prosthetic acceptance and reintegrate psychologically, socially, and physically back to the military unit or to civilian life.
Ziegler-Graham K. MacKenzie EJ. Ephraim PL. Travison TG. Brookmeyer R.
Estimating the prevalence of limb loss in the United States: 2005 to 2050.Arch Phys Med Rehabil. 2008 Mar;89(3):422-9.
It is of great importance, for planning and allocation of health care resources, to calculate future need. Therefore Ziegler-Graham and colleagues performed this study to estimate the current prevalence of limb loss in the United States and project the future prevalence to the year 2050.
Estimates were constructed by using a combination of age-, sex-, and race-specific incidence rates for amputation and age-, sex-, and race-specific assumptions about mortality. Incidence rates were derived from the 1988 to 1999 Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project, corrected for the likelihood of reamputation among those undergoing amputation for vascular disease. Incidence rates were assumed to remain constant over time and applied to historic mortality and population data along with the best available estimates of relative risk, future mortality, and future population projections. The authors also assessed the sensitivity of our projections to changed incidence.
The study group reported that in the year 2005, 1.6 million persons were living with the loss of a limb, that means 1 amputee in every 190 Americans. Of these subjects, 42% were nonwhite and 38% had an amputation secondary to dysvascular disease with diabetes mellitus as an additional diagnosis. It was calculated that the number of people living with the loss of a limb will more than double by the year 2050 to 3.6 million. If incidence rates secondary to dysvascular disease can be reduced by 10%, this number would be lowered by 225,000.
Prosthetics/biomechanics
Vrieling A H. van Keeken H G. Schoppen T. Otten E. Halbertsma J P K. Hof A L. Postema K.
Gait initiation in lower limb amputees
The transition from standing to walking is a task that challenges balance control, neural mechanisms, muscle activity and biomechanical forces. Gait initiation requires two skills that may be limited in amputees; propulsion and balance control. The authors studied limitations in function and adjustment strategies during gait initiation in uni-transtibial and uni-transfemoral amputees. The result from the amputee group was compared with an able bodied control group. The outcomes of the study were leading limb preference, temporal variables, ground reaction forces, and centre of pressure shift.
The study group observed that amputees demonstrated a decrease in peak anterior ground reaction force, a smaller or absent posterior centre of pressure shift, and a lower gait initiation velocity. The main adjustment strategies used by amputees were loading more on the non-affected limb, prolonging the period of propulsive force production in the non-affected limb and initiating gait preferably with the prosthetic limb.
The authors concluded that since an intact ankle joint and musculature is of major importance in gait initiation, functional limitations and adjustment strategies in transfemoral and transtibial amputees were similar. Amputees should be advised to initiate gait with the prosthetic limb, since fewer limitations in function were found and less adjustment strategies were needed in this condition. Further they surmised that a facilitation of the initiation process by achieving a more active ankle function could be made by improvement of prosthetic properties.
Vrieling A H. van Keeken H G. Schoppen T. Otten E. Halbertsma J P K. Hof A L. Postema K.
Gait termination in lower limb amputeesGait & Posture 27 (2008) 82–90
Gait termination is a common movement in everyday life that places a large demand on the control of postural stability, which requires a complex integration and cooperation of the neuromuscular system. Lower limb amputees’ limited functions force them to adjust the strategies of the termination of the gait. The authors wanted to find out how uni-transtibial and uni-transfemoral amputees were limited in function and to assess their adjustment strategies during gait termination. The result from the amputee group was compared with an able bodied control group.
The outcome measures were: leading limb preference, temporal variables, lower limb joint angles, ground reaction forces, and centre of pressure
shift.
It was found that amputees, in comparison to able bodied people, showed a decreased peak braking ground reaction force in the prosthetic limb, no
anterior centre of pressure shift during leading with the prosthetic limb and an increased mediolateral centre of pressure shift. Several adjustment strategies were used by amputees to compensate for the limitations in function such as preference for the non-affected limb as leading limb, longer production of braking force in the non-affected limb, decreased gait termination velocity and more weight-bearing on the non-affected limb.
The study group concluded that limitations in function and adjustment strategies were generally similar in transfemoral and transtibial amputees. Amputees were not able to increase the braking force and to shift the centre of pressure anteriorly due to the lack of active ankle function. Leading with the non-affected limb is preferred for sufficient deceleration and balance control, but not always applicable. Further they suggested that it is important that amputees are trained in gait termination during rehabilitation. The authors also concluded that prosthetic design should focus on a more active role for the prosthetic foot and knee.
To topOrthotics /biomechanics
Tescher A N. Rindflesch A B. YoudasJ W. Jacobson T M. DownerL L. Miers A
G. Basford J R. Cullinane D C. Stevens S R. Pankratz S. Decker P A.
Range-of-Motion Restriction and Craniofacial Tissue-Interface Pressure From Four Cervical Collars
Rigid cervical collars are commonly applied to immobilise the cervical spine in trauma patients. It is well known that occipital pressure ulcers easily develop after prolonged use of such collar. The authors wanted to determine which rigid cervical collar had the most restriction of the cervical range of motion and which caused the least tissue breakdown. They assessed four commercial cervical collars (Aspen, Philadelphia, Miami J, and Miami J with Occian back [Miami J/Occian])
The study was performed on forty-eight healthy volunteers. Cervical range of motion (sagittal, coronal, and rotatory) was measured in seated position without and with collars. The pressure interface was measured by pressure sensor pads in both seated and supine position.
The authors reported that all collars significantly restricted the cervical range of motion in all planes. The Philadelphia and standard Miami J collars were the most restrictive. Regarding pressure measurements in supine position Miami J and Miami J/Occian back had the lowest, whereas Aspen and Philadelphia collars had the greatest. For upright measurements, the Miami J/Occian back produced the smallest mean values.
The authors concluded that the collars that best allowed for a compromise between restriction of cervical motion and low mandibular and occipital pressure measurements were Miami J and Miami J/Occian back.
Tehraninasr, Ali, Saeedi, Hassan, Forogh, Bijan, Bahramizadeh, Mahmood and Keyhani, Mohammad Reza (2008)
Effects of insole with toe-separator and night splint on patients with painful hallux valgus: A comparative study. Prosthetics and Orthotics International, 32:1, 79 – 83
The most obvious feature of hallux valgus is the lateral deviation of the great toe which is caused by a progressive deformation of the forefoot. Several methods to treat this common problem are available.
The study group wanted to compare the effects of wearing an insole with toe separator and a night splint on hallux valgus regarding intermetatarsal angles and the intensity of pain in a group of 30 female patients suffering from painful hallux valgus deformity. Half of the group received an insole with toe separator, the other half received a night splint. The intensity of foot pain was evaluated by the 10 cm Visual Analogue Scale before receiving the intervention and after the 3-months follow-up period. Hallux valgus angle and intermetatarsal angle were obtained through radiographic measurements before and after the 3-month study period.
The result showed that the reduction of pain was significant in the group that received an insole with toe separator, whereas in the other group no significant difference was obtained. The hallux valgus angle and intermetatarsal angle decreased in both groups; however, the reduction was not significant.
The authors conclusion based on the result of this study was that the insole with toe separator seems to be more effective in reducing the pain in patients with painful hallux valgus deformity. Although neither orthoses decreased hallux valgus and intermetatarsal angulations, both prevented an increase of the angulation.
To topBionics
Chappell PH. Cranny A. Cotton DPJ. White NM. Beeby SP.
Sensory motor systems of artificial and natural hands
Since the surgeon Ambroise Paré designed an anthropomorphic hand for wounded soldiers in the 16th century there have been advances in technology through the use of computer-aided design, modern materials, electronic controllers and sensors to realise artificial hands that have good functionality and reliability.
In this article Chappell and his colleagues described and discussed the highlights of the similarities and differences between natural and artificial hands with reference to the Southampton hand.
They reported that the natural neuromuscular systems reveal a complexity which can only partly be realised today with technology. The natural anatomical structure of parts of the systems can be made artificially, for instance the antagonist muscles using tendons. These solutions look promising as they are based on the natural form, but in practice they lack the desired physical specification. Concepts of the lower spinal loops can in principle be mimicked. Some future devices will require greater skills from the surgeon to create the interface between the natural system and an artificial device. Such developments may offer a more natural control with ease of use for the limb deficient person.
Quality management
Ramstrand, N. and Brodtkorb, T. -H. (2008)
Considerations for developing an evidenced-based practice in orthotics and prosthetics.
Evidence-based practice is a demand, placed on medical and allied health professionals, that has increased considerably. It is likely that this demand will increase since reimbursement agencies are increasingly requiring clinicians to demonstrate the cost and quality of life benefits associated with the provision of orthopaedic devices.
Ramstrand and Brodtkorb have reviewed the state of evidence-based practice in the prosthetics and orthotics industry today and defined the importance of it. Key areas that need to be addressed in order to promote evidence-based practice within the profession have also been highlighted.
The authors used following definition of evidence-based medicine: “the conscious and systematic use of best available research evidence in making decisions about the care of individual patients”.
Ramstrand and Brodtkorb suggested that evidence-based practice has to be prioritized within the profession and that a cultural change needs to be initiated, that supports clinician collaboration regarding their research in daily work. Further, the authors highlighted the need for prosthetists/orthotists to become more active in producing research rather than relying on other professional groups to contribute to their professional body of knowledge. The education of prosthetists and orthotists as well as the clinical setting have an important role in facilitation of the implementation of evidence-based medicine.
Simoens S. De Coster S. Moldenaers I. Guillaume P. Depoorter A. Van den Steen D. Van de Sande S. Debruyne H. Ramaekers D. Lonac M.
Reforming the Belgian market for orthotic braces: What can we learn from the international experience?Health Policy 86 (2008) 195–203
The market of orthotics suffers from lack of transparency, creating a potential for a sub-optimal use of limited resources.
Simoens and collegues aimed to review regulations governing outpatient orthotic braces (neck, wrist and knee braces) in France, the Netherlands
and Sweden with a view to reform the Belgian market. To learn about the regulations they derived information about the regulatory framework from analysis of legal texts and from a survey completed by national experts.
The authors found strategies to keep down prices including public procurement in Sweden, maximum prices in France, and exclusion of expensive braces from reimbursement in the Netherlands. Reimbursement was linked to a chronic condition or a medical indication in France, the Netherlands and Sweden. To gain reimbursement, the cost-effectiveness of orthotic braces needed to be demonstrated in France and the Netherlands. Orthotic braces tended to initially be prescribed by a specialist physician and distributed by orthotists, medical equipment shops and/or community pharmacies.
Extensive government intervention existed in the outpatient orthotic brace market in the studied countries. The recommendations made by the study group to reform the Belgian market for prefabricated orthotic braces are as follows:
- separate reimbursement for service provision from reimbursement for braces
- set prices by means of a tendering process or an international price comparison
- make reimbursement conditional on effectiveness and cost-effectiveness of braces.
Össur Academy is looking forward to providing you with more interesting scientific news in September!
Thank you for reading,
Össur Academy.
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