Demographics and discharge outcomes of dysvascular and non-vascular lower limb amputees at a subacute rehabilitation unit: A 7-year series

Objective To examine personal and social demographics, and rehabilitation discharge outcomes of dysvascular and non-vascular lower limb amputees. Methods In total, 425 lower limb amputation inpatient rehabilitation admissions (335 individuals) from 2005 to 2011 were examined. Admission and discharge descriptive statistics (frequency, percentages) were calculated and compared by aetiology. Results Participants were male (74%), aged 65 years (s.d. 14), born in Australia (72%), had predominantly dysvascular aetiology (80%) and a median length of stay 48 days (interquartile range (IQR): 25–76). Following amputation, 56% received prostheses for mobility, 21% (n = 89) changed residence and 28% (n = 116) required community services. Dysvascular amputees were older (mean 67 years, s.d. 12 vs 54 years, s.d. 16; P < 0.001) and recorded lower functional independence measure – motor scores at admission (z = 3.61, P < 0.001) and discharge (z = 4.52, P < 0.001). More nonvascular amputees worked before amputation (43% vs 11%; P < 0.001), were prescribed a prosthesis by discharge (73% vs 52%; P < 0.001) and had a shorter length of stay (7 days, 95% confidence interval: –3 to 17), although this was not statistically significant. Conclusions Differences exist in social and demographic outcomes between dysvascular and non-vascular lower limb amputees.

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.

Exploiting parallax in panoramic capture to construct light fields

We show that the parallax motion resulting from non-nodal rotation in panorama capture can be exploited for light field construction from commodity hardware. Automated panoramic image capture typically seeks to rotate a camera exactly about its nodal point, for which no parallax motion is observed. This can be difficult or impossible to achieve due to limitations of the mounting or optical systems, and consequently a wide range of captured panoramas suffer from parallax between images. We show that by capturing such imagery over a regular grid of camera poses, then appropriately transforming the captured imagery to a common parameterisation, a light field can be constructed. The resulting four-dimensional image encodes scene geometry as well as texture, allowing an increasingly rich range of light field processing techniques to be applied. Employing an Ocular Robotics REV25 camera pointing system, we demonstrate light field capture,refocusing and low-light image enhancement.

Fibroin-based materials support co-cultivation of limbal epithelial and stromal cells

The silk protein fibroin (Bombyx mori) provides a potential substrate for use in ocular tissue reconstruction. We have previously demonstrated that transparent membranes produced from fibroin support cultivation of human limbal epithelial (HLE) cells (Tissue Eng A. 14(2008)1203-11). We extend this body of work to studies of human limbal stromal cell (HLS) growth on fibroin in the presence and absence of serum. Also, we investigate the ability to produce a bi-layered composite scaffold of fibroin with an upper HLE layer and lower HLS layer.

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.

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.

Static load bearing exercises during rehabilitation of individuals with transfemoral amputation fitted with osseointegrated implant: Load compliance

Osseointegration has been introduced in the orthopaedic surgery in the 1990’s in Gothenburg (Sweden). To date, there are two frequently used commercially available human implants: the OPRA (Integrum, Sweden) and ILP (Orthodynamics, Germany) systems. The rehabilitation program with both systems include some form of static load bearing exercises. These latter involved following a load progression that is monitored by the bathroom scale, providing only the load applied on the vertical axis. The loading data could be analysed through different biomechanical variables. For instance, the load compliance, corresponding to the difference between the load recommended (LR) and the load actually applied on the implant, will be presented here.

Load bearing exercises and functional outcome of individuals with transfemoral amputation fitted with OPRA fixation

Individuals with lower limb amputation fitted with an OPRA osseointegrated fixation are facing an extensive rehabilitation program including static load bearing exercises (LBE). The application of a suitable amount of stress stimulates osseointegration and prepares the bone to tolerate the forces and moments that will be incurred during activities of daily living (ADL. At present, the monitoring is typically carried out using a normal bathroom weighing scale. This scale provides information only on the magnitude of the vertical component of the applied force. The moment around the long axis of the fixation when the femur is perpendicular to the ground is not assessed and neither are the components of force and moment generated on the other two axes.

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).

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.

Hip joint stabilization vs. propulsion and resistance in individuals with transfemoral amputation

Joint moments and joint powers are widely used to determine the effects of rehabilitation programs and prosthetic components (e.g., alignments). A complementary analysis of the 3D angle between joint moment and joint angular velocity has been proposed to assess whether the joints are predominantly driven or stabilized.

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].