Cost effectiveness of osseointegration

Individuals with limb amputation fitted with conventional socket-suspended prostheses often experience socket-related discomfort leading to a significant decrease in quality of life. Bone-anchored prostheses are increasingly acknowledged as viable alternative method of attachment of artificial limb. In this case, the prosthesis is attached directly to the residual skeleton through a percutaneous fixation. To date, a few osseointegration fixations are commercially available. Several devices are at different stages of development particularly in Europe and the US. [1-15] Clearly, surgical procedures are currently blooming worldwide. Indeed, Australia and Queensland, in particular, have one of the fastest growing populations. Previous studies involving either screw-type implants or press-fit fixations for bone-anchorage have focused on biomechanics aspects as well as the clinical benefits and safety of the procedure. [16-25] In principle, bone-anchored prostheses should eliminate lifetime expenses associated with sockets and, consequently, potentially alleviate the financial burden of amputation for governmental organizations. Sadly, publications focusing on cost-effectiveness are sparse. In fact, only one study published by Haggstrom et al (2012), reported that “despite significantly fewer visits for prosthetic service the annual mean costs for osseointegrated prostheses were comparable with socket-suspended prostheses”.[26] Consequently, governmental organizations such as Queensland Artificial Limb Services (QALS) are facing a number of challenges while adjusting financial assistance schemes that should be fair and equitable to their clients fitted with bone-anchored prostheses. Clearly, more scientific evidence extracted from governmental databases is needed to further consolidate the analyses of financial burden associated with both methods of attachment (i.e., conventional sockets prostheses, bone-anchored prostheses). The purposes of the presentation will be: 1. To outline methodological avenues to assess the cost-effectiveness of bone-anchored prostheses compared to conventional sockets prostheses, 2. To highlight the potential obstacles and limitations in cost-effectiveness analyses of bone-anchored prostheses, 3. To present preliminary results of a cost-comparison analysis focusing on the comparison of the costs expressed in dollars over QALS funding cycles for both methods of attachment.

Osseointegration internationally: Australia is playing a key role?

Individuals with limb amputation fitted with conventional socket-suspended prostheses often experience socket-related discomfort leading to a significant decrease in quality of life. Bone-anchored prostheses are increasingly acknowledged as viable alternative method of attachment of artificial limb. In this case, the prosthesis is attached directly to the residual skeleton through a percutaneous fixation. To date, a few osseointegration fixations are commercially available. Several devices are at different stages of development particularly in Europe and the US.[1-15] Clearly, surgical procedures are currently blooming worldwide. Indeed, Australia and Queensland in particular have one of the fastest growing populations. Previous studies involving either screw-type implants or press-fit fixations for bone-anchorage have focused on fragmented biomechanics aspects as well as the clinical benefits and safety of the procedure. [16-25] However, very few publications have synthetized this information and provided an overview of the current developments in bone-anchored prostheses worldwide, let alone in Australia. The purposes of the presentation will be: 1. To provide an overview of the state-of-art developments in bone-anchored prostheses with as strong emphasis on the design of fixations, treatment, benefits, risks as well as future opportunities and challenges, 2. To present the current international developments of procedures for bone-anchored prostheses in terms of numbers of centers, number of cases and typical case-mix, 3. To highlight the current role Australia is playing as a leader worldwide in terms of growing population, broadest range of case-mix, choices of fixations, development of reimbursement schemes, unique clinical outcome registry for evidence-based practice, cutting-edge research, consumer demand and general public interest.

Quantifying uncertainty in parameter estimates for stochastic models of collective cell spreading using approximate Bayesian computation

Wound healing and tumour growth involve collective cell spreading, which is driven by individual motility and proliferation events within a population of cells. Mathematical models are often used to interpret experimental data and to estimate the parameters so that predictions can be made. Existing methods for parameter estimation typically assume that these parameters are constants and often ignore any uncertainty in the estimated values. We use approximate Bayesian computation (ABC) to estimate the cell diffusivity, D, and the cell proliferation rate, λ, from a discrete model of collective cell spreading, and we quantify the uncertainty associated with these estimates using Bayesian inference. We use a detailed experimental data set describing the collective cell spreading of 3T3 fibroblast cells. The ABC analysis is conducted for different combinations of initial cell densities and experimental times in two separate scenarios: (i) where collective cell spreading is driven by cell motility alone, and (ii) where collective cell spreading is driven by combined cell motility and cell proliferation. We find that D can be estimated precisely, with a small coefficient of variation (CV) of 2–6%. Our results indicate that D appears to depend on the experimental time, which is a feature that has been previously overlooked. Assuming that the values of D are the same in both experimental scenarios, we use the information about D from the first experimental scenario to obtain reasonably precise estimates of λ, with a CV between 4 and 12%. Our estimates of D and λ are consistent with previously reported values; however, our method is based on a straightforward measurement of the position of the leading edge whereas previous approaches have involved expensive cell counting techniques. Additional insights gained using a fully Bayesian approach justify the computational cost, especially since it allows us to accommodate information from different experiments in a principled way.

Evaluation framework to assess benefits and harms of bone-anchored prosthesis

Bone-anchored prostheses are increasingly acknowledged as viable alternative method of attachment of artificial limb compared to socket-suspended prostheses. To date, a few osseointegration fixations are commercially available. Several devices are at different stages of development particularly in Europe and the US. Clearly, the current momentum experienced worldwide is creating a need for a standardized evaluation framework to assess the benefits and safety of each procedure.

Improving wound management for residents in Residential Aged Care Facilities: National dissemination and implementation of the evidence based Champions for Skin Integrity Program

Overview The incidence of skin tears, pressure injuries and chronic wounds increases with age [1-4] and therefore is a serious issue for staff and residents in Residential Aged Care Facilities (RACFs). A pilot project funded in Round 2 of the Encouraging Best Practice in Residential Aged Care (EBPRAC) program by the then Australian Government Department of Health and Ageing found that a substantial proportion of residents in aged care facilities experienced pressure injuries, skin tears or chronic wounds. It also found the implementation of the evidence based Champions for Skin Integrity (CSI) model of wound care was successful in significantly decreasing the prevalence and severity of wounds in residents, improving staff skills and knowledge of evidence based wound management, increasing staff confidence with wound management, increasing implementation of evidence based wound management and prevention strategies, and increasing staff awareness of their roles in evidence based wound care at all levels [5]. Importantly, during the project, the project team developed a resource kit on evidence based wound management. Two critical recommendations resulting from the project were that: - The CSI model or a similar strategic approach should be implemented in RACFs to facilitate the uptake of evidence based wound management and prevention - The resource kit on evidence based wound management should be made available to all Residential Aged Care Facilities and interested parties A proposal to disseminate or rollout the CSI model of wound care to all RACFs across Australia was submitted to the department in 2012. The department approved funding from the Aged Care Services Improvement Healthy Ageing Grant (ACSIHAG) at the same time as the Round 3 of the Encouraging Better Practice in Aged Care (EBPAC) program. The dissemination involved two crucial elements: 1. The updating, refining and distribution of a Champions for Skin Integrity Resource Kit, more commonly known as a CSI Resource Kit and 2. The presentation of intensive one day Promoting Healthy Skin “Train the Trainer” workshops in all capital cities and major regional towns across Australia Due to demand, the department agreed to fund a second round of workshops focussing on regional centres and the completion date was extended to accommodate the workshops. Later, the department also decided to host a departmental website for a number of clinical domains, including wound management, so that staff from the residential aged care sector had easy access to a central repository of helpful clinical resource material that could be used for improving the health and wellbeing of their older adults, consumers and carers. CSI Resource Kit Upgrade and Distribution: At the start of the project, a full evidence review was carried out on the material produced during the EBPRAC-CSI Stage 1 project and the relevant evidence based changes were made to the documentation. At the same time participants in the EBPRAC-CSI Stage 1 project were interviewed for advice on how to improve the resource material. Following this the documentation, included in the kit, was sent to independent experts for peer review. When this process was finalised, a learning designer and QUT’s Visual Communications Services were engaged to completely refine and update the design of the resources, and combined resource kit with the goal of keeping the overall size of the kit suitable for bookshelf mounting and the cost at reasonable levels. Both goals were achieved in that the kit is about the same size as a 25 mm A4 binder and costs between $19.00 and $28.00 per kit depending on the size of the print run. The dissemination of the updated CSI resource kit was an outstanding success. Demand for the kits was so great that a second print run of 2,000 kits was arranged on top of the initial print run of 4,000 kits. All RACFs across Australia were issued with a kit, some 2,740 in total. Since the initial distribution another 1,100 requests for kits has been fulfilled as well as 1,619 kits being distributed to participants at the Promoting Healthy Skin workshops. As the project was winding up a final request email was sent to all workshop participants asking if they required additional kits or resources to distribute the remaining kits and resources. This has resulted in requests for 200 additional kits and resources. Feedback from the residential aged care sector and other clinical providers who have interest in wound care has been very positive regarding the utility of the kit, (see Appendix 4). Promoting Healthy Skin Workshops The workshops also exceeded the project team’s initial objective. Our goal of providing workshop training for staff from one in four facilities and 450 participants was exceeded, with overwhelming demand for workshop places resulting in the need to provide a second round of workshops across Australia. At the completion of the second round, 37 workshops had been given, with 1286 participants, representing 835 facilities. A number of strategies were used to promote the workshops ranging from invitations included in the kit, to postcard mail-outs, broadcast emailing to all facilities and aged care networks and to articles and paid advertising in aged care journals. The most effective method, by far, was directly phoning the facilities. This enabled the caller to contact the relevant staff member and enlist their support for the workshop. As this is a labour intensive exercise, it was only used where numbers needed bolstering, with one venue rising from 3 registrants before the calls to 53 registrants after. The workshops were aimed at staff who had the interest and the capability of implementing evidence-based wound management within their facility or organisation. This targeting was successful in that a large proportion (68%) of participants were Registered Nurses, Nurse Managers, Educators or Consultants. Twenty percent were Endorsed Enrolled Nurses with the remaining 12% being made up of Personal Care Workers or Allied Health Professionals. To facilitate long term sustainability, the workshop employed train-the-trainer strategies. Feedback from the EBPRAC-CSI Stage 1 interviews was used in the development of workshop content. In addition, feedback from the workshop conducted at the end of the EBPRAC-CSI Stage 1 project suggested that change management and leadership training should be included in the workshops. The program was trialled in the first workshop conducted in Brisbane and then rolled out across Australia. Participants were asked to complete pre and post workshop surveys at the beginning and end of the workshop to determine how knowledge and confidence improved over the day. Results from the pre and post surveys showed significant improvements in the level of confidence in attendees’ ability to implement evidence based wound management. The results also indicated a significant increase in the level of confidence in ability to implement change within their facility or organisation. This is an important indication that the inclusion of change management/leadership training with clinical instruction can increase staff capacity and confidence in translating evidence into practice. To encourage the transfer of the evidence based content of the workshop into practice, participants were asked to prepare an Action Plan to be followed by a simple one page progress report three months after the workshop. These reports ranged from simple (e.g. skin moisturising to prevent skin tears), to complex implementation plans for introducing the CSI model across the whole organisation. Outcomes described in the project reports included decreased prevalence of skin tears, pressure injuries and chronic wounds, along with increased staff and resident knowledge and resident comfort. As stated above, some organisations prepared large, complex plans to roll out the CSI model across their organisation. These plans included a review of the organisation’s wound care system, policies and procedures, the creation of new processes, the education of staff and clients, uploading education and resource material onto internal electronic platforms and setting up formal review and evaluation processes. The CSI Resources have been enthusiastically sought and incorporated into multiple health care settings, including aged care, acute care, Medicare Local intranets (e.g. Map of Medicine e-pathways), primary health care, community and home care organisations, education providers and New Zealand aged and community health providers. Recommendations: Recommendations for RACFs, aged care and health service providers and government  Skin integrity and the evidence-practice gap in this area should be recognised as a major health issue for health service providers for older adults, with wounds experienced by up to 50% of residents in aged care settings (Edwards et al. 2010). Implementation of evidence based wound care through the Champions for Skin Integrity model in this and the pilot project has demonstrated the prevalence of wounds, wound healing times and wound infections can be halved.  A national program and Centre for Evidence Based Wound Management should be established to: - expand the reach of the model to other aged care facilities and health service providers for older adults - sustain the uptake of models such as the Champions for Skin Integrity (CSI) model - ensure current resources, expertise and training are available for consumers and health care professionals to promote skin integrity for all older adults  Evidence based resources for the CSI program and similar projects should be reviewed and updated every 3 – 4 years as per NH&MRC recommendations  Leadership and change management training is fundamental to increasing staff capacity, at all levels, to promote within-organisation dissemination of skills and knowledge gained from projects providing evidence based training Recommendations for future national dissemination projects  A formal program of opportunities for small groups of like projects to share information and resources, coordinate activities and synergise education programs interactively would benefit future national dissemination projects - Future workshop programs could explore an incentive program to optimise attendance and reduce ‘no shows’ - Future projects should build in the capacity and funding for increased follow-up with workshop attendees, to explore the reasons behind those who are unable to translate workshop learnings into the workplace and identify factors to address these barriers.

Osseointegrated prosthetic limb for amputees: Over hundred cases

The Osseointegrated Prosthetic Limb (OPL) was introduced in 2011. Prior to its advent all prostheses consisted of stump and socket mechanisms which did not changed dramatically since Ambroise Pare lower limb prosthesis in 1525. These socket prostheses failed to address a few major requirements of normal gait. Our hypothesis was that using an Osseointegrated Prosthetic limb will result in superior function of daily activities, without compromising patients’ safety.The aims of this paper are (A) to describe the surgical procedure of the OPL; and (B) to present data on potential risks and benefits with assessment of clinical and functional outcomes at follow up

Osseointegrated prosthetic limb for amputees: Single stage surgery

The Osseointegrated Prosthetic Limb (OPL) was introduced in 2011. The socket prostheses failed to address a few major requirements of normal gait. Our hypothesis was that using an Osseointegrated Prosthetic limb will result in superior function of daily activities, without compromising patients’ safety. Traditionally this surgery was done as a two-stage procedure. The aims of this study were (A)to describe the single - surgical procedure of the OPL; and (B)To present data on potential risks and benefits with sssessment of clinical and functional outcomes at follow up.

Transcutaneous bone-anchoring prosthesis with knee replacement: A novel treatment for amputees

Over the last two decades, Transcutaneous Bone-Anchored Prosthesis (TCBAP) has proven to be an effective alternative for prosthetic attachment for amputees, particularly for individuals unable to wear a socket. However, the load transmitted through a typical TCBAP to the residual tibia and knee joint can be unbearable for transtibial amputees with knee arthritis. The aims of this study are (A) to describe the surgical procedure combining TKR with TCBAP for the first time; and (B) to present preliminary data on potential risks and benefits with assessment of clinical and functional outcomes at follow up.

Osseointegration for limb loss: Can Australia play a key role?

Individuals with limb amputation fitted with conventional socket-suspended prostheses often experience socket related discomfort leading to a significant decrease in quality of life. Most of these concerns can be overcome by surgical techniques enabling bone-anchored prostheses. In this case, the prosthesis is attached directly to the residual skeleton through a percutaneous implant. The aim of this study is to present the current advances in these surgical techniques worldwide with a strong focus on the developments in Australia and Queensland.

Spatio-temporal characteristics of locomotion and functional outcomes of individuals with transfemoral amputation fitted with OPRA fixation

The conventional method of attachment of prosthesis involves a socket. A new method relying on osseointegrated fixation has emerged in the last decades. It has significant prosthetic benefits. Only a few studies demonstrated the biomechanical benefits. The ultimate aim of this study was to characterise the functional outcome of individuals with lower limb amputation fitted with osseointegrated fixation, which can be assess through temporal and spatial gait characteristics. The specific objective of this study was to present the key temporal and spatial gait characteristics of individuals with transfemoral amputation (TFA).

Temporal and spatial gait characteristics of transfemoral amputees fitted with osseointegrated fixation: preliminary data

The conventional method of attachment of prosthesis involves on a socket. A new method relying on osseointegrated fixation is emerging. It has significant prosthetic benefits. Only a few studies demonstrated the biomechanical benefits. The ultimate aim of this study was to characterise the functional outcome of transfemoral amputees fitted with osseointegrated fixation, which can be assess through temporal and spatial gait characteristics. The specific objective of this preliminary study was to present the key temporal and spatial gait characteristics.

Spatio-temporal characteristics of locomotion of transfemoral amputees fitted with bone-anchored prosthesis

The conventional method of attachment of prosthesis involves on a socket. A new method relying on osseointegrated fixation is emerging. It has significant prosthetic benefits. Only a few studies demonstrated the biomechanical benefits. The specific objective of this study was to present the key temporal and spatial gait characteristics for unilateral amputation. The ultimate aim of this study was to characterise the functional outcome of the individual with transfemoral lower limb amputation fitted with osseointegrated fixation, which can be assess through temporal and spatial gait characteristics.

Static load bearing exercises during rehabilitation of individuals with transfemoral amputation fitted with osseointegrated implant: Kinetic analysis

The desire to solve problems caused by socket prostheses in transfemoral amputees and the acquired success of osseointegration in the dental application has led to the introduction of osseointegration in the orthopedic surgery. Since its first introduction in 1990 in Gothenburg Sweden the osseointegrated (OI) orthopedic fixation has proven several benefits[1]. The surgery consists of two surgical procedures followed by a lengthy rehabilitation program. The rehabilitation program after an OI implant includes a specific training period with a short training prosthesis. Since mechanical loading is considered to be one of the key factors that influence bone mass and the osseointegration of bone-anchored implants, the rehabilitation program will also need to include some form of load bearing exercises (LBE). To date there are two frequently used commercially available human implants. We can find proof in the literature that load bearing exercises are performed by patients with both types of OI implants. We refer to two articles, a first one written by Dr. Aschoff and all and published in 2010 in the Journal of Bone and Joint Surgery.[2] The second one presented by Hagberg et al in 2009 gives a very thorough description of the rehabilitation program of TFA fitted with an OPRA implant. The progression of the load however is determined individually according to the residual skeleton’s quality, pain level and body weight of the participant.[1] Patients are using a classical bathroom weighing scale to control the load on the implant during the course of their rehabilitation. The bathroom scale is an affordable and easy-to-use device but it has some important shortcomings. The scale provides instantaneous feedback to the patient only on the magnitude of the vertical component of the applied force. The forces and moments applied along and around the three axes of the implant are unknown. Although there are different ways to assess the load on the implant for instance through inverse dynamics in a motion analysis laboratory [3-6] this assessment is challenging. A recent proof- of-concept study by Frossard et al (2009) showed that the shortcomings of the weighing scale can be overcome by a portable kinetic system based on a commercial transducer[7].

Dynamic input to determine hip joint moments, power and work on the prosthetic limb of transfemoral amputees: ground reactions vs knee reactions

Study Design: Comparative analysis Background: Calculations of lower limbs kinetics are limited by floor-mounted force-plates. Objectives: Comparison of hip joint moments, power and mechanical work on the prosthetic limb of a transfemoral amputee calculated by inverse dynamics using either the ground reactions (force-plates) or knee reactions (transducer). Methods: Kinematics, ground reactions and knee reactions were collected using a motion analysis system, two force-plates and a multi-axial transducer mounted below the socket, respectively. Results: The inverse dynamics using ground reactions under-estimated the peaks of hip energy generation and absorption occurring at 63 % and 76 % of the gait cycle (GC) by 28 % and 54 %, respectively. This method over-estimated a phase of negative work at the hip (from 37 %GC to 56 %GC) by 24%. It under-estimated the phases of positive (from 57 %GC to 72 %GC) and negative (from 73 %GC to 98 %GC) work at the hip by 11 % and 58%, respectively. Conclusions: A transducer mounted within the prosthesis has the capacity to provide more realistic kinetics of the prosthetic limb because it enables assessment of multiple consecutive steps and a wide range of activities without issues of foot placement on force-plates. CLINICAL RELEVANCE The hip is the only joint that an amputee controls directly to set in motion the prosthesis. Hip joint kinetics are associated with joint degeneration, low back pain, risks of fall, etc. Therefore, realistic assessment of hip kinetics over multiple gait cycles and a wide range of activities is essential.

Bone-anchored prosthesis: Evidence that “gains” overcome the “pain”

Most of socket related discomforts leading to a significant decrease in quality of life of individuals with limb amputation can be overcome by surgical techniques enabling bone-anchored prostheses. To date, the OPRA two-stage procedure (i.e., S1, S2) is the most acknowledged treatment. However, surgical implantations of osseointegrated fixations are developing at an unprecedented pace worldwide.[1-18] Clearly, this option is becoming accessible to a wide range of individuals with limb amputations. The team led by Dr Rickard Branemark has published a number of landmark articles each focusing on a particular aspect (e.g., health related quality of life, functional outcomes, bone remodelling, infection rate). [1-3, 19-32] However, evidences presented in this prospective study are remarkable. Functional outcome, health-related quality of life and complications were considered concurrently for a large population (i.e., 51 participants) over an extended period of time (i.e., up to year follow up). Therefore, the “gain” and “pain” of the whole procedure were truly contrasted for the first time. The results confirmed that OPRA surgical and rehabilitation procedures improved significantly prosthetic use, mobility, global situation and fewer problems. Furthermore, the authors reported 47 episodes of infections for 63% (32) participants between post-op S1 and two years follow up. A total of 87% (41) were superficial infections recorded for 28 participants between post-op S2 and two years follow up, while 13% (6) were deep infections occurring for 4 participants during post-op S1 and S2. As expected, post-op S2 phase was the most prone to both infections. More importantly, the vast majority of infections were effectively treated with oral antibiotics. Clearly, this study provided definitive evidence that the benefits of OPRA fixation overcome complications. This article is also establishing reporting standards and benchmark data for future studies focusing on bone-anchored prostheses.