| 1. |
- Benca, E., et al.
(författare)
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Patient-Specific Guides for Accurate and Precise Positioning of Osseointegrated Implants in Transfemoral Amputations: A Proof-of-Concept In Vitro Study
- 2023
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Ingår i: Medicina-Lithuania. - : MDPI AG. - 1010-660X. ; 59:3
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives: The treatment of transfemoral amputees using osseointegrated implants for prosthetic anchorage requires accurate implant positioning when using threaded bone-anchoring implants due to the curvature of the femur and the risk of cortical penetration in misaligned implants. This study investigated the accuracy and precision in implant positioning using additively manufactured case-specific positioning guides. Materials and Methods: The geometry and density distribution of twenty anatomic specimens of human femora were assessed in quantitative computed tomography (QCT) scanning. The imaging series were used to create digital 3D specimen models, preoperatively plan the optimal implant position and manufacture specimen-specific positioning guides. Following the surgical bone preparation and insertion of the fixture (threaded bone-anchoring element) (OPRA; Integrum AB, Molndal, Sweden), a second QCT imaging series and 3D model design were conducted to assess the operatively achieved implant position. The 3D models were registered and the deviations of the intraoperatively achieved implant position from the preoperatively planned implant position were analyzed as follows. The achieved, compared to the planned implant position, was presented as resulting mean hip abduction or adduction (A/A) and extension or flexion (E/F) and mean implant axis offset in medial or lateral (M/L) and anterior or posterior (A/P) direction measured at the most distal implant axis point. Results: The achieved implant position deviated from the preoperative plan by 0.33 +/- 0.33 degrees (A/A) and 0.68 +/- 0.66 degrees (E/F) and 0.62 +/- 0.55 mm (M/L) and 0.68 +/- 0.56 mm (A/P), respectively. Conclusions: Using case-specific guides, it was feasible to achieve not only accurate but also precise positioning of the implants compared to the preoperative plan. Thus, their design and application in the clinical routine should be considered, especially in absence of viable alternatives.
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| 2. |
- Benca, E., et al.
(författare)
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Thermal Effects during Bone Preparation and Insertion of Osseointegrated Transfemoral Implants
- 2021
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 21:18
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Tidskriftsartikel (refereegranskat)abstract
- Background: The preparation of bone for the insertion of an osseointegrated transfemoral implant and the insertion process are performed at very low speeds in order to avoid thermal damages to bone tissue which may potentially jeopardize implant stability. The aim of this study was to quantify the temperature increase in the femur at different sites and insertion depths, relative to the final implant position during the stepwise implantation procedure. Methods: The procedure for installation of the osseointegrated implant was performed on 24 femoral specimens. In one specimen of each pair, the surgery was performed at the clinically practiced speed, while the speed was doubled in the contralateral specimen. Six 0.075 mm K fine gauge thermocouples (RS Components, Sorby, UK) were inserted into the specimen at a distance of 0.5 mm from the final implant surface, and six were inserted at a distance of 1.0 mm. Results: Drilling caused a temperature increase of <2.5 degrees C and was not statistically significantly different for most drill sizes (0.002 < p < 0.845). The mean increase in temperature during thread tapping and implant insertion was <5.0 degrees C, whereas the speed had an effect on the temperature increase during thread tapping. Conclusions: Drilling is the most time-consuming part of the surgery. Doubling the clinically practiced speed did not generate more heat during this step, suggesting the speed and thus the time- and cost-effectiveness of the procedure could be increased. The frequent withdrawal of the instruments and removal of the bone chips is beneficial to prevent temperature peaks, especially during thread tapping.
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| 3. |
- Earley, Eric, 1989, et al.
(författare)
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Cutting Edge Bionics in Highly Impaired Individuals: A Case of Challenges and Opportunities
- 2024
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Ingår i: IEEE Transactions on Neural Systems and Rehabilitation Engineering. - 1558-0210 .- 1534-4320. ; 32, s. 1013-1022
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Tidskriftsartikel (refereegranskat)abstract
- Highly impaired individuals stand to benefit greatly from cutting-edge bionic technology, however concurrent functional deficits may complicate the adaptation of such technology. Here, we present a case in which a visually impaired individual with bilateral burn injury amputation was provided with a novel transradial neuromusculoskeletal prosthesis comprising skeletal attachment via osseointegration and implanted electrodes in nerves and muscles for control and sensory feedback. Difficulties maintaining implant hygiene and donning and doffing the prosthesis arose due to his contralateral amputation, ipsilateral eye loss, and contralateral impaired vision necessitating continuous adaptations to the electromechanical interface. Despite these setbacks, the participant still demonstrated improvements in functional outcomes and the ability to control the prosthesis in various limb positions using the implanted electrodes. Our results demonstrate the importance of a multidisciplinary, iterative, and patient-centered approach to making cutting-edge technology accessible to patients with high levels of impairment.
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| 4. |
- Farina, D., et al.
(författare)
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Toward higher-performance bionic limbs for wider clinical use
- 2021
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Ingår i: Nature Biomedical Engineering. - : Springer Science and Business Media LLC. - 2157-846X. ; 7:4, s. 473-85
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Tidskriftsartikel (refereegranskat)abstract
- Most prosthetic limbs can autonomously move with dexterity, yet they are not perceived by the user as belonging to their own body. Robotic limbs can convey information about the environment with higher precision than biological limbs, but their actual performance is substantially limited by current technologies for the interfacing of the robotic devices with the body and for transferring motor and sensory information bidirectionally between the prosthesis and the user. In this Perspective, we argue that direct skeletal attachment of bionic devices via osseointegration, the amplification of neural signals by targeted muscle innervation, improved prosthesis control via implanted muscle sensors and advanced algorithms, and the provision of sensory feedback by means of electrodes implanted in peripheral nerves, should all be leveraged towards the creation of a new generation of high-performance bionic limbs. These technologies have been clinically tested in humans, and alongside mechanical redesigns and adequate rehabilitation training should facilitate the wider clinical use of bionic limbs. This Perspective argues that technologies for the neural interfacing of robotic devices with the body that have been clinically tested in humans should be leveraged toward the creation of a new generation of high-performance bionic limbs.
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| 5. |
- Gstoettner, C., et al.
(författare)
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Successful salvage via re-osseointegration of a loosened implant in a patient with transtibial amputation
- 2021
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Ingår i: Prosthetics and Orthotics International. - : Ovid Technologies (Wolters Kluwer Health). - 0309-3646 .- 1746-1553. ; 45:1, s. 76-80
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Tidskriftsartikel (refereegranskat)abstract
- Case Description: Osseointegration is a relatively new technique for prosthetic limb attachment that offers various improvements for patients with amputation and facilitates joint preservation. We present a case of implant loosening during rehabilitation in a patient with transtibial amputation that was successfully managed through a combination of measures, aiming to promote re-osseointegration of the implant. Objectives: Not much is known about structured management of adverse events after osseointegration. Septic or aseptic loosening is currently regarded as implant failure, prompting removal and possible re-implantation at a later stage. The objective of this case report was to evaluate the feasibility of salvaging a loosened implant. Study Design: Case report. Treatment: A novel treatment approach was employed to enable renewed osseointegration of the implant. First, the bone-implant interface was disrupted and renewed through axial rotation and distal repositioning of the implant. Afterwards, extracorporal shockwave therapy and antibiotic treatment were administered. Prosthetic rehabilitation was then started anew. Regular follow-up x-rays and clinical evaluations were conducted, including standardized outcome tests. Outcomes: These combined measures led to a successful re-osseointegration of the implant. In a 21-month follow-up, the patient regained a stable and secure gait pattern, using his prosthesis every day for 15 hours and scoring above average on standardized outcome measures. Conclusion: This represents the first report of implant salvage after failed primary osseointegration. As the associated risks of this novel treatment are very low, investigations are warranted to evaluate this approach on a larger scale.
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| 6. |
- Hobusch, G. M., et al.
(författare)
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Advanced techniques in amputation surgery and prosthetic technology in the lower extremity
- 2020
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Ingår i: EFORT Open Reviews. - : Bioscientifica. - 2396-7544 .- 2058-5241. ; 5:10, s. 724-741
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Tidskriftsartikel (refereegranskat)abstract
- Bone-anchored implants give patients with unmanage-able stump problems hope for drastic improvements in function and quality of life and are therefore increasingly considered a viable solution for lower-limb amputees and their orthopaedic surgeons, despite high infection rates. Regarding diversity and increasing numbers of implants worldwide, efforts are to be supported to arrange an international bone-anchored implant register to transparently overview pros and cons. Due to few, but high-quality, articles about the beneficial effects of targeted muscle innervation (TMR) and regenerative peripheral nerve interface (RPNI), these surgical techniques ought to be directly transferred into clinical protocols, observations and routines. Bionics of the lower extremity is an emerging cutting-edge technology. The main goal lies in the reduction of recognition and classification errors in changes of ambulant modes. Agonist-antagonist myoneuronal interfaces may be a most promising start in controlling of actively powered ankle joints. As advanced amputation surgical techniques are becoming part of clinical routine, the development of financing strategies besides medical strategies ought to be boosted, leading to cutting-edge technology at an affordable price. Microprocessor-controlled components are broadly available, and amputees do see benefits. Devices from different manufacturers differ in gait kinematics with huge inter individual varieties between amputees that cannot be explained by age. Active microprocessor-controlled knees/ ankles (A-MPK/As) might succeed in uneven ground walking. Patients ought to be supported to receive appropriate prosthetic components to reach their everyday goals in a desirable way. Increased funding of research in the field of prosthetic technology could enhance more high-quality research in order to generate a high level of evidence and to identify individuals who can profit most from microprocessor controlled prosthetic components.
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| 7. |
- Hochgeschurz, S., et al.
(författare)
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Avian extremity reconstruction via osseointegrated leg-prosthesis for intuitive embodiment
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- For large avians such as vultures, limb loss leads to loss of ambulation and eventually death from malnutrition. Prosthetic devices may replace the limb, however, conventional prosthetic sockets are not feasible in feathered limbs and the extreme stress and strain of unreflected daily use in animals. Osseointegration is a novel technique, where external prosthetic parts are connected directly to a bone anchor to provide a solid skeletal-attachment. This concept provides a high degree of embodiment since osseoperception will provide direct intuitive feedback allowing natural use of the limb in gait and feeding. Here we demonstrate for the first time an osseointegrated bionic reconstruction of a limb in a vulture after a tarsometatarsal amputation with a longterm follow-up. © 2021, The Author(s).
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| 8. |
- Li, Yan, et al.
(författare)
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Osseointegrated amputation prostheses and implanted electrodes
- 2021
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Ingår i: Bionic Limb Reconstruction. - Cham : Springer International Publishing. ; , s. 45-55
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The load transfer from the external prosthesis to the residual limb via the socket can cause significant stress on the soft tissues, leading to irritation and skin ulcers. Osseointegrated bone-anchored prostheses systems create a direct structural and functional connection between the prosthesis and residual skeleton. Up to date, standardized implant systems, surgical techniques, and postoperative rehabilitation protocols have been developed for osseointegrated prostheses for the rehabilitation of amputees (OPRA), which has resulted in better functionality, fewer complications, and a better quality of life for implant recipients. The OPRA implant systems can now incorporate neuromuscular electrodes to facilitate myoelectric control and sensory feedback, which is especially important for upper extremity amputees. The latest development, called the osseointegrated human-machine gateway, allows for permanent implantation of neuromuscular electrodes, which provide long-term stable signals for myoelectric control, independent of limb position or environmental conditions, as well as artificial sensory feedback. In addition, the modular design of this system allows any part to be upgraded or replaced with minimal disturbance to the other components. The osseointegrated implants and the human-machine gateway represent frontiers in amputee rehabilitation.
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| 9. |
- Mastinu, Enzo, 1987, et al.
(författare)
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Neural feedback strategies to improve grasping coordination in neuromusculoskeletal prostheses
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Conventional prosthetic arms suffer from poor controllability and lack of sensory feedback. Owing to the absence of tactile sensory information, prosthetic users must rely on incidental visual and auditory cues. In this study, we investigated the effect of providing tactile perception on motor coordination during routine grasping and grasping under uncertainty. Three transhumeral amputees were implanted with an osseointegrated percutaneous implant system for direct skeletal attachment and bidirectional communication with implanted neuromuscular electrodes. This neuromusculoskeletal prosthesis is a novel concept of artificial limb replacement that allows to extract control signals from electrodes implanted on viable muscle tissue, and to stimulate severed afferent nerve fibers to provide somatosensory feedback. Subjects received tactile feedback using three biologically inspired stimulation paradigms while performing a pick and lift test. The grasped object was instrumented to record grasping and lifting forces and its weight was either constant or unexpectedly changed in between trials. The results were also compared to the no-feedback control condition. Our findings confirm, in line with the neuroscientific literature, that somatosensory feedback is necessary for motor coordination during grasping. Our results also indicate that feedback is more relevant under uncertainty, and its effectiveness can be influenced by the selected neuromodulation paradigm and arguably also the prior experience of the prosthesis user.
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| 10. |
- Ortiz Catalan, Max Jair, 1982, et al.
(författare)
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A highly integrated bionic hand with neural control and feedback for use in daily life
- 2023
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Ingår i: Science Robotics. - 2470-9476. ; 8:83
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Tidskriftsartikel (refereegranskat)abstract
- Restoration of sensorimotor function after amputation has remained challenging because of the lack of human-machine interfaces that provide reliable control, feedback, and attachment. Here, we present the clinical implementation of a transradial neuromusculoskeletal prosthesis-a bionic hand connected directly to the user's nervous and skeletal systems. In one person with unilateral below-elbow amputation, titanium implants were placed intramedullary in the radius and ulna bones, and electromuscular constructs were created surgically by transferring the severed nerves to free muscle grafts. The native muscles, free muscle grafts, and ulnar nerve were implanted with electrodes. Percutaneous extensions from the titanium implants provided direct skeletal attachment and bidirectional communication between the implanted electrodes and a prosthetic hand. Operation of the bionic hand in daily life resulted in improved prosthetic function, reduced postamputation, and increased quality of life. Sensations elicited via direct neural stimulation were consistently perceived on the phantom hand throughout the study. To date, the patient continues using the prosthesis in daily life. The functionality of conventional artificial limbs is hindered by discomfort and limited and unreliable control. Neuromusculoskeletal interfaces can overcome these hurdles and provide the means for the everyday use of a prosthesis with reliable neural control fixated into the skeleton.
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| 11. |
- Ortiz Catalan, Max Jair, 1982, et al.
(författare)
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Self-Contained Neuromusculoskeletal Arm Prostheses
- 2020
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 382:18, s. 1732-1738
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Tidskriftsartikel (refereegranskat)abstract
- After transhumeral amputation, four patients had implantation of a self-contained, osseointegrated prosthesis with a neuromusculoskeletal interface that allowed intuitive control of the prosthetic hand and arm over 3 to 7 years. A video shows use of the prostheses in daily life. We report the use of a bone-anchored, self-contained robotic arm with both sensory and motor components over 3 to 7 years in four patients after transhumeral amputation. The implant allowed for bidirectional communication between a prosthetic hand and electrodes implanted in the nerves and muscles of the upper arm and was anchored to the humerus through osseointegration, the process in which bone cells attach to an artificial surface without formation of fibrous tissue. Use of the device did not require formal training and depended on the intuitive intent of the user to activate movement and sensory feedback from the prosthesis. Daily use resulted in increasing sensory acuity and effectiveness in work and other activities of daily life. (Funded by the Promobilia Foundation and others.)
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| 12. |
- Thesleff, Alexander, 1986, et al.
(författare)
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Low plasticity burnishing improves fretting fatigue resistance in bone-anchored implants for amputation prostheses
- 2022
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Ingår i: Medical Engineering & Physics. - : Elsevier BV. - 1350-4533 .- 1873-4030. ; 100
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Tidskriftsartikel (refereegranskat)abstract
- Fretting fatigue is a common problem for modular orthopedic implants which may lead to mechanical failure of the implant or inflammatory tissue responses due to excessive release of wear debris. Compressive residual stresses at the contacting surfaces may alleviate the problem. Here we investigate the potential of a surface enhancement method known as low plasticity burnishing (LPB) to increase the fretting fatigue resistance of bone-anchored implants for skeletal attachment of limb prostheses. Rotation bending fatigue tests performed on LPB treated and untreated test specimens demonstrate that the LPB treatment leads to statistically significantly increased resistance to fretting fatigue (LPB treated test specimens withstood on average 108,780 load cycles as compared with 37,845 load cycles for untreated test specimens, p = 0.004). LPB treated test specimens exhibited less wear at the modular interface as compared with untreated test specimens. This surface treatment may lead to reduced risk of fretting induced component failure and a reduced need for revision of implant system componentry.
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| 13. |
- Thesleff, Alexander, 1986, et al.
(författare)
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The effect of cortical thickness and thread profile dimensions on stress and strain in bone-anchored implants for amputation prostheses
- 2022
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Ingår i: Journal of the Mechanical Behavior of Biomedical Materials. - : Elsevier BV. - 1751-6161 .- 1878-0180. ; 129
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Tidskriftsartikel (refereegranskat)abstract
- Skeletal attachment of limb prostheses ensures load transfer between the prosthetic leg and the skeleton. For individuals with lower limb amputation, these loads may be of substantial magnitude. To optimize the design of such systems, knowledge about the structural interplay between implant design features, dimensional changes, and material properties of the implant and the surrounding bone is needed. Here, we present the results from a parametric finite element investigation on a generic bone-anchored implant system of screw design, exposed to external loads corresponding to average and high ambulatory loading. Of the investigated parameters, cortical thickness had the largest effect on the stress and strain in the bone-anchored implant and in the cortical bone. 36%–44% reductions in maximum longitudinal stress in the bone-anchored implant was observed as a result of increased cortical thickness from 2 mm to 5 mm. A change in thread depth from 1.5 mm to 0.75 mm resulted in 20%–22% and 10%–18% reductions in maximum longitudinal stress in the bone-anchored implant at 2 mm and 5 mm cortical thickness respectively. The effect of changes in the thread root radius was less prominent, with 8% reduction in the maximum longitudinal stress in the bone-anchored implant being the largest observed effect, resulting from an increased thread root radius from 0.1 mm to 0.5 mm at a thread depth of 1.5 mm. Autologous transplantation of bone tissue distal to the fixture resulted in reductions in the longitudinal stress in the percutaneous abutment. The observed stress reduction of 10%–31% was dependent on the stiffness of the transplanted bone graft and the cortical thickness of surrounding bone. Results from this investigation may guide structural design optimization for bone-anchored implant systems for attachment of limb prostheses. © 2022 The Authors
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| 14. |
- Zbinden, Jan, 1994, et al.
(författare)
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Improved control of a prosthetic limb by surgically creating electro-neuromuscular constructs with implanted electrodes
- 2023
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Ingår i: Science translational medicine. - 1946-6234 .- 1946-6242. ; 15:704
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Tidskriftsartikel (refereegranskat)abstract
- Remnant muscles in the residual limb after amputation are the most common source of control signals for prosthetic hands, because myoelectric signals can be generated by the user at will. However, for individuals with amputation higher up the arm, such as an above-elbow (transhumeral) amputation, insufficient muscles remain to generate myoelectric signals to enable control of the lost arm and hand joints, thus making intuitive control of wrist and finger prosthetic joints unattainable. We show that severed nerves can be divided along their fascicles and redistributed to concurrently innervate different types of muscle targets, particularly native denervated muscles and nonvascularized free muscle grafts. We engineered these neuromuscular constructs with implanted electrodes that were accessible via a permanent osseointegrated interface, allowing for bidirectional communication with the prosthesis while also providing direct skeletal attachment. We found that the transferred nerves effectively innervated their new targets as shown by a gradual increase in myoelectric signal strength. This allowed for individual flexion and extension of all five fingers of a prosthetic hand by a patient with a transhumeral amputation. Improved prosthetic function in tasks representative of daily life was also observed. This proof-of-concept study indicates that motor neural commands can be increased by creating electro-neuromuscular constructs using distributed nerve transfers to different muscle targets with implanted electrodes, enabling improved control of a limb prosthesis.
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