Long-term functional and clinical outcome of combined targeted muscle reinnervation and osseointegration for functional bionic reconstruction in transhumeral amputees: a case series.

OBJECTIVE: To describe and evaluate the combination of osseointegration and nerve transfers in 3 transhumeral amputees. DESIGN: Case series. PATIENTS: Three male patients with a unilateral traumatic transhumeral amputation. METHODS: Patients received a combination of osseointegration and targeted muscle reinnervation surgery. Rehabilitation included graded weight training, range of motion exercises, biofeedback, table-top prosthesis training, and controlling the actual device. The impairment in daily life, health-related quality of life, and pain before and after the intervention was evaluated in these patients. Their shoulder range of motion, prosthesis embodiment, and function were documented at a 2- to 5-year follow-up. RESULTS: All 3 patients attended rehabilitation and used their myoelectric prosthesis on a daily basis. Two patients had full shoulder range of motion with the prosthesis, while the other patient had 55° of abduction and 45° of anteversion. They became more independent in their daily life activities after the intervention and incorporated their prosthesis into their body scheme to a high extent. CONCLUSION: These results indicate that patients can benefit from the combined procedure. However, the patients' perspective, risks of the surgical procedures, and the relatively long rehabilitation procedure need to be incorporated in the decision-making.

Low plasticity burnishing improves fretting fatigue resistance in bone-anchored implants for amputation prostheses.

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.

Thermal Effects during Bone Preparation and Insertion of Osseointegrated Transfemoral Implants.

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 °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 °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.

Advanced techniques in amputation surgery and prosthetic technology in the lower extremity.

Bone-anchored implants give patients with unmanageable 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. Cite this article: EFORT Open Rev 2020;5:724-741. DOI: 10.1302/2058-5241.5.190070.

Targeted Muscle Reinnervation and Osseointegration for Pain Relief and Prosthetic Arm Control in a Woman with Bilateral Proximal Upper Limb Amputation.

BACKGROUND: Bilateral proximal upper limb loss is a dramatic life-changing event. Replacement of the lost function with prosthetic arms, including multiple mechatronic joints, has remained a challenge from the control, comfort, and pain management perspectives. Targeted muscle reinnervation (TMR) is a peripheral nerve surgical procedure proposed to improve the intuitive control of the prosthetic arm and for neuroma and phantom pain management. Moreover, osseointegrated percutaneous implants (OPIs) allow for direct skeletal attachment of the prosthetic arm, ensuring freedom of movement to the patient's residual articulations. CASE DESCRIPTION: We have reported the first combined application of TMR and an OPI to treat a 24-year-old woman with a bilateral amputation at the shoulder level on the right side and at the very proximal transhumeral level on the left side. TMR was performed bilaterally in a single day, accounting for the peculiar patient's anatomy, as preparatory stage to placement of the OPI, and considering the future availability of implantable electromyographic sensors. The 2 OPI surgeries on the left side were completed after 8.5 months, and prosthetic treatment was completed 17 months after TMR. CONCLUSIONS: The use of TMR resolved the phantom pain bilaterally and the right-side neuroma pain. It had also substantially reduced the left side neuroma pain. The actual prosthetic control result was intuitive, although partially different from expectations. At 2 years after TMR, the patient reported improvement in essential activities of daily living, with a remarkable preference for the OPI prosthesis. Only 1 suspected case of superficial infection was noted, which had resolved. Overall, this combined treatment required a highly competent multidisciplinary team and exceptional commitment by the patient and her family.

Caprine Models of the Agonist-Antagonist Myoneural Interface Implemented at the Above- and Below-Knee Amputation Levels.

BACKGROUND: Traditional approaches to amputation are not capable of reproducing the dynamic muscle relationships that are essential for proprioceptive sensation and joint control. In this study, the authors present two caprine models of the agonist-antagonist myoneural interface (AMI), a surgical approach designed to improve bidirectional neural control of a bionic limb. The key advancement of the AMI is the surgical coaptation of natively innervated agonist-antagonist muscle pairs within the residual limb. METHODS: One AMI was surgically created in the hindlimb of each of two African Pygmy goats at the time of primary transtibial amputation. Each animal was also implanted with muscle electrodes and sonomicrometer crystals to enable measurement of muscle activation and muscle state, respectively. Coupled agonist-antagonist excursion in the agonist-antagonist myoneural interface muscles was measured longitudinally for each animal. Fibrosis in the residual limb was evaluated grossly in each animal as part of a planned terminal procedure. RESULTS: Electromyographic and muscle state measurements showed coupled agonist-antagonist motion within the AMI in the presence of both neural activation and artificial muscle stimulation. Gross observation of the residual limb during a planned terminal procedure revealed a thin fibrotic encapsulation of the AMI constructs, which was not sufficient to preclude coupled muscle excursion. CONCLUSIONS: These findings highlight the AMI's potential to provide coupled motion of distal agonist-antagonist muscle pairs preserved during below- or above-knee amputation at nearly human scale. Guided by these findings, it is the authors' expectation that further development of the AMI architecture will improve neural control of advanced limb prostheses through incorporation of physiologically relevant muscle-tendon proprioception.

Osseointegrated Percutaneous Prosthetic System for the Treatment of Patients With Transfemoral Amputation: A Prospective Five-year Follow-up of Patient-reported Outcomes and Complications.

INTRODUCTION: Direct skeletal attachment of prostheses has previously been shown to improve patient-reported outcome (PRO) measures of individuals with transfemoral amputation (TFA) at 2-year follow-up. This prospective study reports the outcomes at 5-year follow-up. METHODS: A total of 51 patients (55 legs) with TFA were included in a prospective study. Complications, success rate, and PRO measures were followed for 5 years. RESULTS: The cumulative fixture survival rate at 5 years was 92%, and the revision-free survival rate was 45%. Thirty-four patients had 70 superficial infections. Eleven patients had 14 deep infections. Fifteen patients had mechanical complications. Four fixtures were removed (ie, one deep infection and three loosening). PRO measures showed significant improvements including more use of the prosthesis, better mobility, fewer issues, and improved physical health-related quality of life (all P < 0.0001) compared with baseline. CONCLUSION: Individuals with TFA at 5-year follow-up had significant improvement in PRO measures, but increases in deep infections and mechanical complications are concerning.

Myoelectric signals and pattern recognition from implanted electrodes in two TMR subjects with an osseointegrated communication interface.

Permanent implantation of electrodes for prosthetic control is now possible using an osseointegrated implant as a long-term stable communication interface (e-OPRA). The number of myoelectric sites to host such electrodes can be increased by Targeted Muscle Reinnervation (TMR). Traditionally, patients need to wait several months before the TMR signals are strong enough to be recorded by electrodes placed over the skin. In this study, we report the evolution of the TMR myoelectric signals recorded from two subjects via implanted electrodes using e-OPRA, and monitored for up to 48 weeks after surgery. The signals were analyzed with regard to amplitude (signal-to-noise ratio), independence (cross-correlation) and myoelectric pattern recognition (classification accuracy). TMR signals appeared at the first follow-up, one month post-surgery, and developed around 20 dB by the last. Cross-correlation between signals decreased over time and converged to a few percentage points. Classification accuracies were over 97% by the last follow up. These preliminary results suggest that implanted electrodes via the e-OPRA interface allow for an earlier and more effective use of motor signals from TMR sites compared to conventional skin surface electrodes.

Osteomyelitis Risk in Patients With Transfemoral Amputations Treated With Osseointegration Prostheses.

BACKGROUND: Percutaneous anchoring of femoral amputation prostheses using osseointegrating titanium implants has been in use for more than 25 years. The method offers considerable advantages in daily life compared with conventional socket prostheses, however long-term success might be jeopardized by implant-associated infection, especially osteomyelitis, but the long-term risk of this complication is unknown. QUESTIONS/PURPOSES: (1) To quantify the risk of osteomyelitis, (2) to characterize the clinical effect of osteomyelitis (including risk of implant extraction and impairments to function), and (3) to determine whether common patient factors (age, sex, body weight, diabetes, and implant component replacements) are associated with osteomyelitis in patients with transfemoral amputations treated with osseointegrated titanium implants. METHODS: We retrospectively analyzed our first 96 patients receiving femoral implants (102 implants; mean implant time, 95 months) treated at our center between 1990 and 2010 for osteomyelitis. Six patients were lost to followup. The reason for amputation was tumor, trauma, or ischemia in 97 limbs and infection in five. All patients were referred from other orthopaedic centers owing to difficulty with use or to be fitted with socket prostheses. If found ineligible for this implant procedure no other treatment was offered at our center. Osteomyelitis was diagnosed by medical chart review of clinical signs, tissue culture results, and plain radiographic findings. Proportion of daily prosthetic use when osteomyelitis was diagnosed was semiquantitatively graded as 1 to 3. Survivorship free from implant- associated osteomyelitis and extraction attributable to osteomyelitis respectively was calculated using the Kaplan-Meier estimator. Indication for extraction was infection not responsive to conservative treatment with or without minor débridement or loosening of implant. RESULTS: Implant-associated osteomyelitis was diagnosed in 16 patients corresponding to a 10-year cumulative risk of 20% (95% CI 0.12-0.33). Ten implants were extracted owing to osteomyelitis, with a 10-year cumulative risk of 9% (95% CI 0.04-0.20). Prosthetic use was temporarily impaired in four of the six patients with infection who did not undergo implant extraction. With the numbers available, we did not identify any association between age, BMI, or diabetes with osteomyelitis; however, this study was underpowered on this endpoint. CONCLUSION: The increased risk of infection with time calls for numerous measures. First, patients should be made aware of the long-term risks, and the surgical team should have a heightened suspicion in patients with method-specific presentation of possible infection. Second, several research questions have been raised. Will the surgical procedure, rehabilitation, and general care standardization since the start of the program result in lower infection rates? Will improved diagnostics and early treatment resolve infection and prevent subsequent extraction? Although not supported in this study, it is important to know if most infections arise as continuous bacterial invasion from the skin and implant interface and if so, how this can be prevented? LEVEL OF EVIDENCE: Level IV, therapeutic study.

Osseointegrated prostheses for rehabilitation following amputation : The pioneering Swedish model.

The direct attachment of osseointegrated (OI) prostheses to the skeleton avoids the inherent problems of socket suspension. It also provides physiological weight bearing, improved range of motion in the proximal joint, as well as osseoperceptive sensory feedback, enabling better control of the artificial limbs by amputees. The present article briefly reviews the pioneering efforts on extremity osseointegration surgeries in Sweden and the development of the OPRA (Osseointegrated Prostheses for the Rehabilitation of Amputees) program. The standard implant design of the OPRA system and surgical techniques are described as well as the special rehabilitation protocols based on surgical sites. The results of long-term follow-up for transradial, transhumeral, and thumb amputee operations are briefly reported including the prospective study of transfemoral amputees according to OPRA protocol. The importance of refinement on implant designs and surgical techniques based on the biomechanical analysis and early clinical trials is emphasized. Future aspects on osseointegration surgery are briefly described, including novel treatment options using implanted electrodes.

Titanium-bone-anchored penile epithesis: preoperative planning and immediate postoperative results.

The principle of osseointegration is accepted and used in reconstructive surgery. This study presents the first series of five patients where titanium implants have been implanted into the pubic bones of female-to-male (FTM) transsexual patients, in order to attach a "bone-anchored" penile epithesis. Following patient selection based on patients' wishes, pubic bones of 10 FTM transsexuals were analysed by CT-scan and a virtual planning was made. A surgical plan was also developed. To date, five FTM transsexuals have undergone the two-stage surgery. During stage-1, two titanium implants ("fixtures") are implanted onto the pubic bone. Four weeks postop, a new CT scan is performed to analyze osseointegration and the final implant position. During stage-2, the soft tissue of the pubic area is reduced; abutments are inserted and passed through the skin. A few weeks after stage 2 surgery, a penile epithesis is connected to the skin-penetrating titanium implants. Two out of 10 patients who received preoperative CT scan presented with smaller pubic bones, not able to accommodate the fixtures as chosen originally. Preoperative virtual planning is crucial for the selection of the appropriate implants size. The stage-1 and stage-2 surgery occurred uneventfully in all five patients. One patient presented with a wound infection 1 week after stage-2 surgery. Postoperative CT scan demonstrates implant osseointegration in all cases. This experimental clinical study demonstrates that titanium osseointegration is feasible onto the pubic bone. This new approach for penile reconstruction constitutes another alternative for both transsexual patients and cases following genital development disorders, post-trauma and surgery.

Outcome of percutaneous osseointegrated prostheses for patients with unilateral transfemoral amputation at two-year follow-up.

OBJECTIVE: To report outcomes regarding general and specific physical health-related quality of life of treatment with percutaneous osseointegrated prostheses. DESIGN: Prospective 2-year case-control study. SETTING: University hospital. PARTICIPANTS: Individuals (N=39; mean age, 44 ± 12.4 y) with unilateral transfemoral amputation as a result of trauma (n=23), tumor (n=11), or other cause (n=5). At baseline, 33 of the 39 participants used socket-suspended prostheses. INTERVENTION: Osseointegrated prosthesis. MAIN OUTCOME MEASURES: Questionnaire for Persons with Transfemoral Amputation (Q-TFA), Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) physical functioning (PF) and physical component summary (PCS), SF-6D, and Physiological Cost Index (PCI). RESULTS: At 2 years postimplantation, 6 of 7 Q-TFA scores improved (P<.0001) compared with baseline (prosthetic use, mobility, problem, global, capability, walking habits). The walking aid subscore did not improve (P=.327). Of the 39 participants, increased prosthesis use was reported by 26, same amount of use by 11, and less use by 2. Improvement was reported in 16 of the 30 separate problem items (P<.05). Unchanged items included problems regarding phantom limb pain and pain from the back, shoulders, and contralateral limb. The PF, PCS, and SF-6D improved a mean of 24.1 ± 21.4 (P<.0001), 8.5 ± 9.7 (P<.0001), and .039 ± .11 (P=.007) points, respectively. Walking energy cost decreased (mean PCI at baseline, .749; mean PCI at follow-up, .61; P<.0001). CONCLUSIONS: Two years after intervention, patients with a unilateral TFA treated with an OPRA implant showed important improvements in prosthetic function and physical quality of life. However, walking aids used and the presence of phantom limb pain and pain in other extremities were unchanged. This information is valuable when considering whether percutaneous osseointegrated prostheses are a relevant treatment option.

Implant survival, adverse events, and bone remodeling of osseointegrated percutaneous implants for transhumeral amputees.

BACKGROUND: Osseointegrated percutaneous implants provide direct anchorage of the limb prosthesis to the residual limb. These implants have been used for the rehabilitation of transhumeral amputees in Sweden since 1995 using a two-stage surgical approach with a 6-month interval between the stages, but results on implant survival, adverse events, and radiologic signs of osseointegration and adaptive bone remodeling in transhumeral amputees treated with this method are still lacking. QUESTIONS/PURPOSES: This study reports on 2- and 5-year implant survival, adverse events, and radiologic signs of osseointegration and bone remodeling in transhumeral amputees treated with osseointegrated prostheses. METHODS: Between 1995 and 2010, we performed 18 primary osseointegrated percutaneous implants and two implant revisions in 18 transhumeral amputees; of those, 16 patients were available for followup at a minimum of 2 years (median, 8 years; range, 2-19 years). These include all transhumeral amputees who have received osseointegrated prostheses and represented approximately 20% of the all transhumeral amputees we evaluated for potential osseointegration during that time; general indications for this approach included transhumeral amputation resulting from trauma or tumor, inability to wear or severe problems wearing a conventional socket prosthesis, eg, very short residual limb, and compliant patients. Medical charts and plain radiographs were retrospectively evaluated. RESULTS: The 2- and 5-year implant survival rates were 83% and 80%, respectively. Two primary and one revised implant failed and were removed because of early loosening. A fourth implant was partially removed because of ipsilateral shoulder osteoarthritis and subsequent arthrodesis. The most common adverse event was superficial infection of the skin penetration site (15 infections in five patients) followed by skin reactions of the skin penetration site (eight), incomplete fracture at the first surgery (eight), defective bony canal at the second surgery (three), avascular skin flap necrosis (three), and one deep implant infection. The most common radiologic finding was proximal trabecular buttressing (10 of 20 implants) followed by endosteal bone resorption and cancellization (seven of 20), cortical thinning (five of 20), and distal bone resorption (three of 20). CONCLUSIONS: The implant system presented a survivorship of 83% at 5 years and a 38% 5-year incidence of infectious complications related to the skin penetration site that were easily managed with nonoperative treatment, which make it a potentially attractive alternative to conventional socket arm prostheses. Osseointegrated arm prostheses have so far only been used in transhumeral amputations resulting from either trauma or tumor. Their use has not been tested and is therefore not recommended in transhumeral amputations resulting from vascular disease. This method could theoretically be superior to socket prostheses, especially in transhumeral amputees with very short residual humerus in which the suspension of a conventional prosthesis is difficult. Comparative studies are needed to support its potential superiority. Moreover, the radiological findings in this study need to be followed over time because some of them are of uncertain long-term clinical relevance.

Acute inflammatory response to laser-induced micro- and nano-sized titanium surface features.

BACKGROUND: The inflammatory process induced by implant surfaces is an important component of the tissue response, where limited knowledge is available regarding the role of surface topography. With laser ablation, a combined micro- and nanoscale surface modification could be created, which have been shown to enhance bone growth and biomechanical stability in vivo. PURPOSE: The aim of this article was to evaluate the early in vivo inflammatory response to laser-modified titanium disks, with machined titanium disks and sham operation sites serving as controls. MATERIALS AND METHODS: Circular disks were installed in a subcutaneous rat model for 24 and 72 hours, where the cell number, cell types, and cytokine levels were evaluated. RESULTS: The results revealed that significantly fewer inflammatory cells (mononuclear and polymorphonuclear) were attracted to the sites with the laser-modified implants compared with the machined titanium implants. Similar concentrations of pro-inflammatory cytokines (TNF-a and MCP-1), together with slightly higher cell viability, were observed around the laser-modified surface compared with the machined surface. CONCLUSIONS: The results in the present study suggest that the combination of surface micro and nano features of the laser-treated surface contributes to the downregulation of early inflammatory events.

Stable fixation of an osseointegated implant system for above-the-knee amputees: titel RSA and radiographic evaluation of migration and bone remodeling in 55 cases.

BACKGROUND AND PURPOSE: Rehabilitation of patients with transfemoral amputations is particularly difficult due to problems in using standard socket prostheses. We wanted to assess long-term fixation of the osseointegrated implant system (OPRA) using radiostereometric analysis (RSA) and periprosthetic bone remodeling. METHODS: 51 patients with transfemoral amputations (55 implants) were enrolled in an RSA study. RSA and plain radiographs were scheduled at 6 months and at 1, 2, 5, 7, and 10 years after surgery. RSA films were analyzed using UmRSA software. Plain radiographs were graded for bone resorption, cancellization, cortical thinning, and trabecular streaming or buttressing in specifically defined zones around the implant. RESULTS: At 5 years, the median (SE) migration of the implant was -0.02 (0.06) mm distally. The rotational movement was 0.42 (0.32) degrees around the longitudinal axis. There was no statistically significant difference in median rotation or migration at any follow-up time. Cancellization of the cortex (plain radiographic grading) appeared in at least 1 zone in over half of the patients at 2 years. However, the prevalence of cancellization had decreased by the 5-year follow-up. INTERPRETATION: The RSA analysis for the OPRA system indicated stable fixation of the implant. The periprosthetic bone remodeling showed similarities with changes seen around uncemented hip stems. The OPRA system is a new and promising approach for addressing the challenges faced by patients with transfemoral amputations.

Osseointegration amputation prostheses on the upper limbs: methods, prosthetics and rehabilitation.

BACKGROUND: The osseointegration programme for upper extremity amputation started in Sweden in 1990, when a titanium fixture was first implanted into a thumb. This method has since been used for transhumeral and below-elbow amputation. The treatment involves two surgical procedures. During the first a titanium fixture is surgically attached to the skeleton, and a second procedure six months later involves a skin penetrating abutment to which the prosthesis is attached. OBJECTIVES: To describe the osseointegration procedure for surgery, prosthetics and rehabilitation. METHODS: Patients with short stumps and previous problems with prosthetic fitting were selected. From 1990 to April 2010, 37 upper limb cases were treated and fitted with prosthesis: 10 thumbs, 1 partial hand, 10 transradial and 16 transhumeral amputations. Of these, 7 patients are currently not prosthetic users. RESULTS: Patients indicated that function and quality of life had improved since osseointegration. CONCLUSION: Osseointegration is an important platform for present and future prosthetic technology. The prosthetic situation is improved due to the stable fixation, freedom of motion and functionality. CLINICAL RELEVANCE: The two-stage osseointegration procedure has the potential to change the rehabilitation strategy for selected upper limb amputees. The method eliminates the need for a socket and the prosthesis will always fit. The stable prosthetic fixation and increased freedom of motion generates improved function. Specially designed components and rehabilitation procedures have been developed.

Osseointegrated titanium implants for limb prostheses attachments: infectious complications.

BACKGROUND: The concept of osseointegration involves direct contact between titanium implant and bone. This transcutaneous prosthetic system for amputees is intended to assure stable long-term fixation. Most metal transcutaneous implants have failed, primarily owing to infection. QUESTIONS/PURPOSES: We determined the frequency and describe the presentation of infectious complications with this novel method. We also evaluated the bacterial flora at the skin-penetration area and its relation to the development of local and implant-related infection. PATIENTS AND METHODS: We prospectively followed 39 patients with arm and leg amputations fitted with transcutaneous osseointegrated titanium implants a mean of 56 months earlier (range, 132-133 months). There were 33 femoral, one tibial, four ulnar, four radial, and three humeral implants. Patients were selected during a 6-month period in 2005 and identically reevaluated after 3 years. Implant infection was defined as definite, probable, or possible based on clinical, radiologic, and microbiologic evidence. RESULTS: The frequency of implant infection was 5% at inclusion and 18% at followup. One patient with infection recovered owing to antibiotic treatment and another patient had the implant removed. Most implant infections had low infectious activity, and in five of the seven patients with infections, prosthetic use was not affected. The most common bacteria in superficial and deep cultures were Staphylococcus aureus and coagulase-negative staphylococci. CONCLUSIONS: Despite frequent colonization around the skin-implant interface by potentially virulent bacteria such as Staphylococcus aureus and bacteria associated with biomedical device infections such as coagulase-negative staphylococci, this titanium implant system for bone-anchored prostheses caused few infections leading to disability or implant removal. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

[A new method for prosthetisation of vascular patients with lower limb amputation: initial experiences with osseointegration technique]. / Alsóvégtag-amputált érbetegek új protetizációs lehetôsége: kezdeti tapasztalataink az osseointegrációs technikával.

INTRODUCTION/AIMS: Prostheses use for lower limb amputees is difficult, while the socket is hard, the prosthesis is heavy. Drawbacks of conventional prosthesis are mainly associated with the socket, therefore osseointegration technique is a promising solution, since it doesn't require a socket. Our aim was to introduce this technique in Hungary and extend indication for vascular patients. METHODS: The method includes two operative and one rehabilitation phases: during first operation a titanium screw is fixed into the femoral bone marrow cavity, this connects to an abutment, which also penetrates the skin, making a direct connection between the femur and the prosthesis during the second intervention. During rehabilitation the patient makes loading exercises and learns to walk with new prosthesis. RESULTS: This method was launched in Hungary in 2005. Two female amputees were operated on initially, their second surgery was performed in 2006 (when titanium screw was applied in the male patients, as well). Incorporation of titanium screw was exquisite, and rehabilitation was successful. One of our male patients died eight months after his first operation due to myocardial infarction. CONCLUSION: Based on our experiences, the osseointegration technique facilitates rehabilitation of vascular patients for prostheses use. Adequate follow-up and stable vascular diseases are not contraindications, although further clinical trials are needed to determine its indication.

One hundred patients treated with osseointegrated transfemoral amputation prostheses--rehabilitation perspective.

Treatment with osseointegrated transfemoral prostheses has been shown to improve quality of life. The treatment has been performed in Sweden since 1990 and consists of two surgical procedures followed by rehabilitation. During the first years, the rehabilitation process was not standardized. In 1999, a treatment protocol called OPRA (Osseointegrated Prostheses for the Rehabilitation of Amputees) was established. This article describes the current rehabilitation protocol and illustrates the overall results. The OPRA rehabilitation protocol is graded to stimulate the process of osseointegration and prepare the patient for unrestricted prosthetic use. It includes initial training with a short training prosthesis followed by gradually increased prosthetic activity. Between May 1990 and June 2008, we treated 100 patients with 106 implants (6 bilaterally; 61% males, 39% females; mean age 43 years; mean time since amputation 11.5 years.) The majority had amputations due to trauma (67%) or tumor (21%) (other = 12%). Currently, 68 patients are using their prostheses (follow-up: 3 months- 17.5 years) and 32 are not (4 are deceased, 7 are before second surgery, 6 are in initial training, 4 are not using prosthesis, and 11 had the implant removed). The majority of treatment failures occurred in patients before we established the OPRA protocol. The implementation of graded rehabilitation is considered to be of utmost importance for improved results.