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.

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.

Biomechanics of transfemoral amputees fitted with osseointegrated fixation: Loading data for evidence-based practice

This presentation will provide an overview of the load applied on the residuum of transfemoral amputees fitted with an osseointegrated fixation during (A) rehabilitation, including static and dynamic load bearing exercises (e.g., rowing, adduction, abduction, squat, cycling, walking with aids), and (B) activities of daily living including standardized activities (e.g., level walking in straight line and around a circle, ascending and descending slopes and stairs) and activities in real world environments.

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.

Classification of activities of daily living of individual with limb loss

The monitoring of the actual activities of daily living of individuals with lower limb amputation is essential for an evidence-based fitting of the prosthesis, more particularly the choice of components (e.g., knees, ankles, feet)[1-4]. The purpose of this presentation was to give an overview of the categorization of the load regime data to assess the functional output and usage of the prosthesis of lower limb amputees has presented in several publications[5, 6]. The objectives were to present a categorization of load regime and to report the results for a case.

Load applied on a bone-anchored transfemoral prosthesis: characterisation of a prosthesis : a pilot study

The objectives of this study were (A) to record the inner prosthesis loading during activities of daily living (ADL), (B) to present a set of variables comparing loading data, and (C) to provide an example of characterisation of two prostheses. The load was measured at 200 Hz using a multi-axial transducer mounted between the residuum and the knee of an individual with unilateral transfemoral amputation fitted with a bone-anchored prosthesis. The load was measured while using two different prostheses including a mechanically (PRO1) and a microprocessor controlled (PRO2) knee during six ADL. The characterisation of prosthesis was achieved using a set of variables split into four categories, including temporal characteristics, maximum loading, loading slopes and impulse. Approximately 360 gait cycles were analysed for each prosthesis. PRO1 showed a cadence improved by 19% and 7%, a maximum force on the long axis reduced by 11% and 19%, as well as an impulse reduced by 32% and 15% during descent of incline and stairs compared to PRO2, respectively. This work confirmed that the proposed apparatus and characterisation can reveal how changes of prosthetic components are translated into inner loading.

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.

One step closer into the design of fall protective device for individuals fitted with a bone-anchored prosthesis

The consequences of falls are often dreadful for individuals with lower limb amputation using bone-anchored prosthesis.[1-5] Typically, the impact on the fixation is responsible for bending the intercutaneous piece that could lead to a complete breakage over time. .[3, 5-8] The surgical replacement of this piece is possible but complex and expensive. Clearly, there is a need for solid data enabling an evidence-based design of protective devices limiting impact forces and torsion applied during a fall. The impact on the fixation during an actual fall is obviously difficult to record during a scientific experiment.[6, 8-13] Consequently, Schwartze and colleagues opted for one of the next best options science has to offer: simulation with an able-bodied participant. They recorded body movements and knee impacts on the floor while mimicking several plausible falling scenarios. Then, they calculated the forces and moments that would be applied at four levels along the femur corresponding to amputation heights.[6, 8-11, 14-25] The overall forces applied during the falls were similar regardless of the amputation height indicating that the impact forces were simply translated along the femur. As expected, they showed that overall moments generally increased with amputation height due to changes in lever arm. This work demonstrates that devices preventing only against force overload do not require considering amputation height while those protecting against bending moments should. Another significant contribution is to provide, for the time, the magnitude of the impact load during different falls. This loading range is crucial to the overall design and, more precisely, the triggering threshold of protective devices. Unfortunately, the analysis of only a single able-bodied participant replicating falls limits greatly the generalisation of the findings. Nonetheless, this case study is an important milestone contributing to a better understanding of load impact during a fall. This new knowledge will improve the treatment, the safe ambulation and, ultimately, the quality of life of individuals fitted with bone-anchored prosthesis.

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.

Direct measurement of prosthetic loading for evidence-based practice

The demand for an evidence-based clinical practice involving lower limb amputees is increasing. Some of the critical care decisions are related to the loading applied on the residuum partially responsible for comfort and functional outcome. This loading can be assessed using inverse dynamics equations. Typically, this method requires a gait laboratory (e.g., 3D motion analysis system, force-plates). It is mainly suited for the analysis only few steps of walking while being expensive and labour intensive. However, recent scientific and industrial developments demonstrated that discrete and light portable sensors can be placed within the prosthesis to measure accurately the loading during an unlimited number of steps and activities of daily living. Several studies indicated that method based on direct measurements might provide more realistic results. Furthermore, it is a user-friendly method more accessible to clinicians, such as prosthetists. The purpose of this symposium will be to give an overview of these additional opportunities for clinicians to obtain relevant data for evidence-based practice. The three main aims will be: • To present some of the equipment used for direct measurements, • To propose ways to analyse some key data sets, • To give some practical example of data sets for transtibial and transfemoral amputees.

How does Australian diabetic foot screening rate on an international Stage?

Background From the conservative estimates of registrants with the National Diabetes Supply Scheme, we will be soon passing 1.1 Million Australians affected by all types of diabetes. The diabetes complications of foot ulceration and amputation are costly to all. These costs can be reduced with appropriate prevention strategies, starting with identifying people at risk through primary care diabetic foot screening. However, levels of diabetic foot screening in Australia are difficult to quantify. Methods This presentation reports on foot screening rates as recorded in the academic literature, national health surveys and national database reports. The focus is on type 1 and type 2 diabetes in adults, and not gestational diabetes or children. Literature searches included diabetic foot screening that occurred in the primary care setting for populations over 2000 people from 2002 to 2014. Searches were performed using Medline and CINAHL as well as internet searches of OECD health databases. The primary outcome measure was foot -screening rates as a percentage of adult diabetic population. Results The lack of a national diabetes database and register hampers efforts to analyse diabetic foot screening levels. The most recent and accurate level for Australian population review was in the AUSDIAB (Australian Diabetes and lifestyle survey) from 2004. This survey reported screening in primary care to be as low as 50%. Countries such as the United Kingdom and United States of America report much higher rates of foot screening (67-88%) using national databases and web based initiatives that involve patients and clinicians. Conclusions Australian rates of diabetic foot screening in primary care centres is ambiguous. Uptake of national registers, incentives and web based systems improve levels of diabetic foot assessment which are the first steps to a healthier diabetic population.

Bone-anchored prosthesis: Update in international developments

This symposium will provide hand-on update on the current development of the load sensors measuring the inner prosthetic loading that can strongly contribute the ever increasing demand for evidence-based clinical practice. Surgical implantations of osseointegrated fixations for bone-anchored prosthesis are developing at an unprecedented pace worldwide (e.g., Australia, UK, Sweden, US). This option is becoming accessible to a wide range of individuals with limb loss. With these new developments come new potential challenges and opportunities for all the stakeholders involved in the prosthetic care of these patients. Clearly, there is a need for those stakeholders, particularly those attending the ISPO, to be informed of the current and upcoming international developments in bone-anchored prostheses. The objectives of this symposium will be: • To present an overview of the current growth of the procedures worldwide (e.g., identification of key players, centers of activities, growth trend) with a strong focus on the introduction of the framework to evaluate the availability of the procedure at national level (e.g., number of patients treated, range of the levels of implantation, number of commercial fixations accessible), • To provide first-hand updates on the latest cutting-edge scientific and clinical developments of fixations and rehabilitations programs (e.g., Innovative design of implant, cost-effectiveness, long-terms rehabilitation outcomes for screw-type fixation, current developments in US, comparative analysis for press-fit type of implant, potential moves toward single-stage surgeries).