Ossur Scientific E-letter

1 October 2007

Ossur Scientific E-letter Issue 3#2007

Ossur Academy's scientific E-letter
Issue 3#2007 (September 30th 2007)

Welcome to the third issue of our 2007 Scientific E-letter

This E-letter includes nine different scientific papers. The articles cover the subjects of amputation/rehabilitation, prosthetics/biomechanics, orthotics/biomechanics, bionics and quality management.
Eight of the selected papers have been published in 2007 and one 2006.

Enjoy the reading!

Amputation / Rehabilitation

Kimura H. Nakanishi T. Nagatomi A. Ochi M.
A New Rehabilitation Method For A Transtibial Amputation Due To Ischemic Lower Limb Disease
Proceedings of ISPO 2007 Vancouver, Page 232

Kimura and his colleagues from Hiroshima, Japan presented the results of treating transtibial amputees with the multiprofessional method presented by Johannesson.

The team performed the amputations using the saggital flap technique. Immediately after the amputations, Össur removable rigid dressings were applied. Unlike plaster of paris, the removable rigid dressing can be hardened and softened repeatedly, to  permit easy observation of the  post operative wound and allow stump volume fluctuations. The rigid dressing was replaced by silicone liners after 5-7 days, which continuously applied pressure to the stumps. The stumps were matured after three to six weeks when ICEX carbon fiber sockets with prosthesis were made. The patients started walking immediately after the prostheses were made.

Kimura et al concluded that this method is considered effective with regard to shortening the treatment time and allowing the patients to start walking again earlier. They assume they can decrease both the time of manufacturing the prosthesis to 15.7 days and the time from operation until discharge to 57.4 days.

Richardson C. Glenn S. Horgan M. Nurmikko T.
A Prospective Study of Factors Associated With the Presence of
Phantom Limb Pain Six Months After Major Lower Limb Amputation In Patients With Peripheral Vascular Disease
The Journal of Pain, Vol xx, No xx (Month), 2007: pp xxx
Article in press

Richardson and his team aimed at finding a way to prevent phantom pain by revealing psychological factors associated with the development of such a pain.

A perspective study was conducted of 59 patients who were interviewed prior to and six months post amputation.

The primary outcome measures were pain and coping style. The results demonstrated that use of high levels of passive coping strategies, such as catastrophizing before the amputation, were associated with phantom pain. Pain was only weakly associated with phantom pain. Post amputation factors  associated with phantom pain were the ability to move the phantomlimb and stump pain.

The authors concluded that in order to avoid phantom pain, psychological as well as physical interventions must be included in the treatment of amputees.

Prosthetics / biomechanics

Johannesson A. Larsson G-U.
ICEX: 10 Year Clinical Experience And Outcome
Proceedings of ISPO 2007 Vancouver, Page 354

Johannesson and Larsson reported about the outcome of using ICEX over a  ten year period. This method includes direct pressure casting with a carbon fibre braid rolled over the silicon liner followed by the immediate manufacturing of a total surface bearing prosthetic socket.

454 lower extremity amputations (LEA) on 346 patients were performed during this period. Out of those, 140 patients were fitted with 175 sockets manufactured with the ICEX technique.

During the studied time span the incidence of major lower extremity amputation decreased by 12% and the share of TT amputations  increased from 53% to 83%. Meanwhile the population of elderly (+65 year) increased by 1.7%. The median age of the studied population was old (79 years), 95% of them suffered from peripheral vascular diseases and 37.7% had diabetes.

From amputation to delivery of a prosthesis, the median time was 41 days. The average time to produce a prosthesis was 2.5 hours. That meant that the rehabilitation could continue. 27% had their socket changed within six months and 73% within one year. Half of the population fit with a prosthesis survived more than five years.

The members of the multidisciplinary team found that this method facilitated the rehabilitation process of the patients. This facilitation was especially notable when dealing with patients with delayed wound healing. The method has also helped surgeons in deciding whether or not to preserve the knee joint.

Graham L E. Datta D. Heller B. Howitt J.
A Comparative study of Conventional and Energy-Storing
Prosthetic Feet in High-Functioning Transfemoral Amputees
Arch Phys Med Rehabil Vol 88, June 2007

Graham and colleagues performed a comparative study between a conventional prosthetic foot (Multiflex) and an energy storing prosthetic foot (Variflex) on six high functioning transfemoral amputees. The feet where compared by analysing the results of gait analysis, timed walking tests and Socket Fit Comfort Score. Both feet were tested on each subject.

It was found that the subjects had a faster walking speed and took more equal step lengths when walking wearing the Variflex foot. Furthermore the gait analysis demostrated that peak ankle dorsiflexion and push-off o n the prosthetic side were greater when walking with Variflex than with Multiflex. Also, the power generated fromthe prosthetic foot at push off using Variflex, was three times higher than that generated with Multiflex.

The study group did not find significant differences between the two feet with regards to temporal symmetry, loading of the prosthetic limb or in the comfort score.

The authors concluded that transfemoral amputees can benefit, from having a more symmetrical gait, by using an energy storing foot.

Orthotics / biomechanics

Desloovere K. Molenaers G. Van Gestel L. Huenaerts C. Van Campenhout A. Callewaert B. Van de Walle P. Seyler J.
How can push-off be preserved during use of an ankle foot
orthosis in children with hemiplegia? A prospective controlled study
Gait & Posture 24 (2006) 142–151

A study of two types of ankle foot orthosis (AFO ) was performed by Desloovere and colleagues. They wanted to evaluate how walking with an AFO affected the third rocker in a group of fifteen hemiplegic children,  between the ages of4 and 10 years.

The children received two varieties of individually made AFOs;a common Posterior Leaf Spring (PLS) and a Dual Carbon Fiber Spring (CFO) AFO. The two AFOs were expected to improve the first rocker by preventing plantar flexion, improving the second rocker by allowing dorsiflexion and improving the third rocker by the return  of energy stored during the second rocker.

The two AFOs (in shoes) were studied and compared with  walking barefoot and with walking in  shoes only by objective gait analysis including 3D-kinematics and kinetics.

Gait analysis showed that cadence, ankle ROM and velocity, knee shock absorption and knee angle in swing were significantly changed in walking with shoes compared to walking barefoot.

When comparing the two AFOs it was found that the CFO produced a significantly higher ankle velocity and larger ROM at push off and an increased power generation and plantar-flexion-moment at pre swing compared to the PLS. All the improvements of the AFOs were not significant when compared to shoes.

The authors concluded that these findings clearly indicate that the effects of using AFO in shoes should always be compared with the effects of walking in shoes alone.

Bionics

Agrawal V R. Gailey R S. O'Toole C O. Gaunaurd I A.
Plantar Pressure Comparisons: Bionic Foot & Ankle System Versus Conventional Foot Designs
Proceedings of ISPO 2007 Vancouver, Page 366

Agrawal and collegues wanted to compare plantar pressure values of the Proprio™ foot with conventional foot designs.

The Proprio™ foot is capable of measuring ankle motion with the help of an accelerometer and the position of the foot with a microprocessor and Terrain Logic™ artificial intelligence software. These qualities  normalize  foot and ankle biomechanics by predicting the orientation of the foot in relation to the surface. A linear actuator uses spatial positions of the ankle and toes to continously correct the foot when walking on  level and unlevel surfaces.

The two feet were compared by using an in-shoe pressure assessment system on two unilateral transtibial amputees testing both feet. The subject's prosthetic foot pressure pattern was compared to the sound foot pressure pattern.

The authors found that the Proprio™ foot appeared to give a more symmetrical distribution of pressure in all the functional activities tested. Furthermore, the Proprio™ demonstrated a greater area of 
heel contact during incline walking and sit to stand activities.

Agraval concluded that these characteristics of the Proprio™ foot may benefit the amputees gait symmetry and biomechanics.

Alimusaj M. Wolf S. Braatz F. Doederlein L.
Gait Analysis Of Transtibial Amputees With A New Microprocessor Controlled Ankle: Preliminary Results
Proceedings of ISPO 2007 Vancouver, Page 456

This study of Almusaj and colleagues compares the kinematics on the Proprio™ foot when it is activated and when it is not activated.

A conventional 3D gait analysis was performed on six unilateral transtibial amputees. Mean values of hip, knee and ankle flexion as well as ankle ROM in swing were analysed.

During level walking in swing the ankle ROM increased  1,4° when the foot was activated. When ascending stairs and ramps the foot dorsiflexed 3°-4° more and the timing of  knee flexion was closer to a normal gait pattern. Descending stairs showed similar result to the two foot conditions. When ascending ramps  additional plantarflexion was seen when the foot was activated.

The study also showed that compensatory mechanisms on proximal and contralateral joints were reduced. Furthermore, the subjects reported a functional benefit.

The authors concluded that the Proprio™ foot is benefical to the 
amputee when walking on unlevel surfaces because stability increases and therefore so does safety. The Proprio™ foot also enables patients to walk with more normal knee and hip joint kinematics, thereby decreasing compensatory actions of the sound limb.

Quality management

Allegranzia B. Storra J. Dziekana G. Leotsakosb a. Donaldsonb L. Pittet D.
The First Global Patient Safety Challenge "Clean Care is Safer Care": from launch to current progress and achievements1
Journal of Hospital Infection (2007) 65(S2) 115–123

Healthcare-associated infection is a very important safety issue affecting the quality of care of hundreds of millions of patients every year in both developed and developing countries. Healthcare-associated infection, which is also called nosocomial infection, is defined as "An infection occurring in a patient during the process of care in a hospital or other healthcare facility which was not present or incubating at the time of admission. This includes infections acquired in the hospital but appearing after discharge and also occupational infections among staff of the facility".

Allegranzia et al report about the status of  the WHO's challenge "World Alliance for Patient Safety"  aimed at implementing several actions to reduce healthcare associated infections worldwide, regardless of the level of development. The challenge was launcheded in October 2004. WHO's goal in the challenge is to ensure patient safety across healthcare settings around the world.

The strategy of the implementation includes the integration of several interventions in the following areas: blood safety, injection safety, clinical procedure safety, water sanitation and waste management, with  hand hygiene i as the cornerstone. Several initiatives have been taken to raise global awareness and to obtain country commitment to support action.

The new Guidelines on Hand Hygiene in Health Care, based on the most reliable scientific evidence available, have been issued in an advanced draft form. An implementation strategy together with a range of practical tools for use in a healthcare setting is proposed to provide solutions to overcome obstacles and improve compliance with hand hygiene practices. 

The core message in the guideline is the promotion of the gold standard method for hand hygiene practices for example, the use of alcohol-based hand rubs rather than hand washing with soap and water. Alcohol based hand ribs are easier, faster, better tolerated and can be cost-effective.

 Five key features are crucial for a successful implementation:
I. engineering controls, leading to system change (alcohol based hand rubs at the point of care and access to safe continuous water supply, soap and towels);
II. healthcare workers' education and training;
III. observation of hand hygiene practices and data feedback to healthcare workers;
IV. in the workplace (technical and promotional posters)
V. creation of an institutional safety climate (active participation at institutional and individual level and individual/institutional self efficacy).

The authors concluded that millions of lives can be saved and major resource savings can be created credited to the efforts generated from the Global Patient Safety Challenge.

Johannesson A. Larsson B.
Functional Outcome After Major Lower Limb Amputation
Proceedings of ISPO 2007 Vancouver, Page 324

Johannesson's and Larsson's multiprofessional team has developed a program for the care of amputees. It includes all the steps from preoperative preparations, through amputation and the hospital stay to  rehabilitation with prosthetic fitting. The goal of the team is that all patients who walked three months before amputation will be walkers again.

The study group wanted to know what could be expected of this group. To measure the outcome of the rehabilitation the team used the "Timed Up and Go" (TUG) and the "Locomotor Capabilities Index" (LCI). The follow-up was conducted after walking was re-established, approximately three months after amputation. This study focused on primary amputations.

The results showed that of the group of 80 subjects (median age: 80 years old), 56 were fitted with a prosthesis. The definitive prosthesis was delivered after an average time of 40 days. The capacity was tested in 41 patients in median time after 97 days. The results of the capacity tests support the idea that very old patients and patients with cognitive deficits can benefit from a prosthesis by having safer transfers, being more independent and having a better quality of life.

Ossur academy is looking forward to providing you with more interesting scientific news in November!

Thanks for reading,
Össur Academy.