Complete tibial nerve lesion secondary to postoperative popliteal pseudoaneurysm following anterior cruciate ligament arthroscopic reconstruction: A series of two patients.

Background: Complications following arthroscopic anterior cruciate ligament reconstruction (ACLR) are rare, but injuries to the popliteal artery can occur. Popliteal pseudoaneurysms are a potential complication and can cause significant morbidity if not diagnosed and treated promptly. Cases Description: We describe the cases of two patients who developed nerve injuries following arthroscopic ACLR, with subsequent diagnosis of a popliteal pseudoaneurysm. The peroneal nerve recovered spontaneously in both cases, while the tibial nerve was reconstructed using autologous nerve grafting. Satisfying, functional recoveries were observed 24 months postoperatively. Conclusion: Prompt diagnosis and effective treatment of popliteal pseudoaneurysms are crucial to prevent further complications. However, timely diagnosis can be challenging due to inconsistent clinical presentations and a low index of suspicion. This case report highlights the need for increased awareness of this uncommon complication and provides insights into its pathophysiological mechanisms.

Reverse Neurocutaneous Flap Based on the Dorsal Branch of the Ulnar Artery for Palm Coverage in Children: Long-Term Results.

PURPOSE: Although the palm is spared mostly in severe burn injuries, it often is affected in children and requires radical excision of contracting scar tissue to allow normal hand development. Since alternatives are limited for palmar coverage, we primarily use a reverse-perfused, neurocutaneous dorsal ulnar artery flap. We report here our long-term follow-up results. METHODS: We reviewed the long-term results of 10 postburn palmar contracture release and flap coverage procedures in 10 children. The applied flap was based distally on the dorsal branch of the ulnar artery and harvested along the ulnar aspect of the hand and wrist. The pivot point of the flap was located dorsally, close to the 4th and 5th metacarpal base. Patients were followed for a median period of 6 years (range, 4-20 years). RESULTS: Flap size ranged from 60-130 mm in length and 20-35 mm in width. This variation in flap dimensions resulted from different hand sizes, because of the various patient ages at surgery. All flaps survived, donor site healing was uneventful, and marginal flap necrosis occurred only once. Satisfactory restoration of range of motion without secondary contractures was observed. Moreover, we detected adequate progressive growth, adaptability and sensory recovery in all flaps. Over time, the flaps mostly become hairless and progressively flattened without debulking. CONCLUSIONS: The importance of this flap lies in the potential for considerable tissue mobilization to cover palmar defects without sacrificing any major vascular axis. The adequate progressive growth of the flap facilitates functional hand development in children. The predictable vascular anatomy, wide range, and durable, thin, and pliable skin make the reverse neurocutaneous dorsal ulnar artery flap an appealing option for soft tissue reconstruction of the palm in children. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Experimental nerve transfer model in the neonatal rat.

Clinically, peripheral nerve reconstructions in neonates are most frequently applied in brachial plexus birth injuries. Most surgical concepts, however, have investigated nerve reconstructions in adult animal models. The immature neuromuscular system reacts differently to the effects of nerve lesion and surgery and is poorly investigated due to the lack of reliable experimental models. Here, we describe an experimental forelimb model in the neonatal rat, to study these effects on both the peripheral and central nervous systems. Within 24 hours after birth, three groups were prepared: In the nerve transfer group, a lesion of the musculocutaneous nerve was reconstructed by selectively transferring the ulnar nerve. In the negative control group, the musculocutaneous nerve was divided and not reconstructed and in the positive control group, a sham surgery was performed. The animal´s ability to adapt to nerve lesions and progressive improvement over time were depict by the Bertelli test, which observes the development of grooming. Twelve weeks postoperatively, animals were fully matured and the nerve transfer successfully reinnervated their target muscles, which was indicated by muscle force, muscle weight, and cross sectional area evaluation. On the contrary, no spontaneous regeneration was found in the negative control group. In the positive control group, reference values were established. Retrograde labeling indicated that the motoneuron pool of the ulnar nerve was reduced following nerve transfer. Due to this post-axotomy motoneuron death, a diminished amount of motoneurons reinnervated the biceps muscle in the nerve transfer group, when compared to the native motoneuron pool of the musculocutaneous nerve. These findings indicate that the immature neuromuscular system behaves profoundly different than similar lesions in adult rats and explains reduced muscle force. Ultimately, pathophysiologic adaptations are inevitable. The maturing neuromuscular system, however, utilizes neonatal capacity of regeneration and seizes a variety of compensation mechanism to restore a functional extremity. The above described neonatal rat model demonstrates a constant anatomy, suitable for nerve transfers and allows all standard neuromuscular analyses. Hence, detailed investigations on the pathophysiological changes and subsequent effects of trauma on the various levels within the neuromuscular system as well as neural reorganization of the neonatal rat may be elucidated. This study was approved by the Ethics Committee of the Medical University of Vienna and the Austrian Ministry for Research and Science (BMWF-66.009/0187-WF/V/3b/2015) on March 20, 2015.

Fascicular shifting in the reconstruction of brachial plexus injuries: an anatomical and clinical evaluation.

OBJECTIVE: Until recently, autologous sensory nerve grafting has remained the gold-standard technique in peripheral nerve reconstruction. However, there are several disadvantages to these grafts, such as donor site morbidity, limited availability, and a qualitative mismatch. Building on this shortage, a new concept, the fascicular shift procedure, was proposed and successfully demonstrated nerve regeneration in a rat nerve injury model. This approach involves harvesting a fascicular group distal to a peripheral nerve injury and shifting it to bridge the defect. The present study aimed to evaluate the clinical applicability of this technique in brachial plexus reconstruction. METHODS: The supra- and infraclavicular nerves of the brachial plexus were bilaterally explored in 18 formalin-fixed cadaveric specimens. Following dissection, their fascicular shifting potential was evaluated. The medial antebrachial cutaneous and sural nerves were investigated and used as references for the required cross-sectional area of potential nerve grafts. Furthermore, 29 brachial plexus injuries, which qualified for surgical repair, were subjected to retrospective analysis. The intraoperatively measured lengths of the harvested and ultimately transplanted nerve grafts served as a basis to assess graft requirements in brachial plexus lesions. RESULTS: The transplanted nerve grafts measured a total length of 51.9 ± 28.1 cm in brachial plexus injuries. The individual inserted nerve grafts averaged 10.3 ± 5.1 cm. In the anatomical exploration, the ulnar and median nerves qualified for fascicular shifting. Their fascicular graft lengths measured 26.6 ± 2.5 cm and 24.8 ± 5.2 cm, respectively. The long thoracic, suprascapular, musculocutaneous, thoracodorsal, and axillary nerves were not suitable for fascicular shifting. The sensory graft length of the medial antebrachial cutaneous nerve measured 20.6 ± 3.4 cm. CONCLUSIONS: In the surgical reconstruction of brachial plexus injuries, fascicular shifting of the ulnar and median nerves provides sufficient donor material. Even though potential donor length is limited in the radial nerve, it may still help to expand the surgical armamentarium in selected clinical scenarios. Overall, the fascicular shift procedure presents a novel alternative to allow modality-matched grafting in the reconstruction of large proximal nerve defects and was found to be an attractive option in brachial plexus reconstruction.

Avian extremity reconstruction via osseointegrated leg-prosthesis for intuitive embodiment.

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.

Bionic reconstruction : Restoration of extremity function with osseointegrated and mind-controlled prostheses.

BACKGROUND: Loss of an extremity at any level has a major impact on a patient's life. Using bionic reconstruction, extremity function can be restored and the patient reintegrated into daily life. Surgical procedures including selective nerve transfer and anchoring of prostheses into bone are combined with structured rehabilitation and modern prosthetic fitting. The patient is thereby able to use the prostheses intuitively and with multiple degrees of freedom. METHODS: This article presents the concept and approach for modern bionic reconstruction in detail and the relevant literature. The nerve transfer matrices for targeted muscle reinnervation (TMR) and the concept of osseointegration to optimally fit a patient with a modern prosthesis are described in detail. As a clinical example, the case of a patient who suffered from traumatic amputation and subsequently received TMR in combination with an osseointegrated implant and structured rehabilitation is presented. RESULTS: Using bionic reconstruction, basic hand functions can be restored and bimanual dexterity can expand the range of daily activities. Besides this approach to bionic reconstruction, its advantages and disadvantages are compared to hand transplantation. The limitations and perspectives of modern bionic reconstruction are also discussed. CONCLUSIONS: Bionic reconstruction is a sophisticated method for restoring extremity function and nowadays can be considered a standard of care for all levels of upper extremity amputations. An interdisciplinary approach and structured rehabilitation are necessary to master prosthetic function to ultimately reintegrate patients into daily life.

Bionic hand as artificial organ: Current status and future perspectives.

Even though the hand comprises only 1% of our body weight, about 30% of our central nervous systems (CNS) capacity is related to its control. The loss of a hand thus presents not only the loss of the most important tool allowing us to interact with our environment, but also leaves a dramatic sensory-motor deficit that challenges our CNS. Reconstruction of hand function is therefore not only an essential part of restoring body integrity and functional wholeness but also closes the loop of our neural circuits diminishing phantom sensation and neural pain. If biology fails to restore meaningful function, today we can resort to complex mechatronic replacement that have functional capabilities that in some respects even outperform biological alternatives, such as hand transplantation. As with replantation and transplantations, the challenge of bionic replacement is connecting the target with the CNS to achieve natural and intuitive control. In recent years, we have developed a number of strategies to improve neural interfacing, signal extraction, interpretation and stable mechanical attachment that are important parts of our current research. This work gives an overview of recent advances in bionic reconstruction, surgical refinements over technological interfacing, skeletal fixation, and modern rehabilitation tools that allow quick integration of prosthetic replacement.

Experimental Testing of Bionic Peripheral Nerve and Muscle Interfaces: Animal Model Considerations.

Introduction: Man-machine interfacing remains the main challenge for accurate and reliable control of bionic prostheses. Implantable electrodes in nerves and muscles may overcome some of the limitations by significantly increasing the interface's reliability and bandwidth. Before human application, experimental preclinical testing is essential to assess chronic in-vivo biocompatibility and functionality. Here, we analyze available animal models, their costs and ethical challenges in special regards to simulating a potentially life-long application in a short period of time and in non-biped animals. Methods: We performed a literature analysis following the PRISMA guidelines including all animal models used to record neural or muscular activity via implantable electrodes, evaluating animal models, group size, duration, origin of publication as well as type of interface. Furthermore, behavioral, ethical, and economic considerations of these models were analyzed. Additionally, we discuss experience and surgical approaches with rat, sheep, and primate models and an approach for international standardized testing. Results: Overall, 343 studies matched the search terms, dominantly originating from the US (55%) and Europe (34%), using mainly small animal models (rat: 40%). Electrode placement was dominantly neural (77%) compared to muscular (23%). Large animal models had a mean duration of 135 ± 87.2 days, with a mean of 5.3 ± 3.4 animals per trial. Small animal models had a mean duration of 85 ± 11.2 days, with a mean of 12.4 ± 1.7 animals. Discussion: Only 37% animal models were by definition chronic tests (>3 months) and thus potentially provide information on long-term performance. Costs for large animals were up to 45 times higher than small animals. However, costs are relatively small compared to complication costs in human long-term applications. Overall, we believe a combination of small animals for preliminary primary electrode testing and large animals to investigate long-term biocompatibility, impedance, and tissue regeneration parameters provides sufficient data to ensure long-term human applications.

Fascicular shifting: a novel technique to overcome large nerve defects.

OBJECTIVE Over the last decade, a number of authors have investigated the utility of different biological and synthetic matrices as alternatives to conventional nerve grafts. However, the autologous nerve graft remains the gold standard, even though it often involves using a pure sensory nerve to reconstruct a mixed or even a pure motor nerve. Furthermore, limited donor sites often necessitate a significant mismatch of needed nerve tissue, especially for large proximal nerve defects such as brachial plexus lesions. Here, the authors present a new technique that overcomes these problems: the fascicular shift procedure (FSP). A fascicular group of the nerve distal to the injury is harvested in a sufficient length to bridge the nerve defect. METHODS The method of fascicular shifting was tested at the sciatic nerve in 45 Lewis rats. In the experimental group, a 15-mm nerve defect was created and reconstructed with a fascicular group that was harvested directly distal to the gap. This group was compared with 1 negative control group (defect without reconstruction) and 3 positive control groups (sensory, motor, and mixed graft). After 12 weeks of nerve regeneration, outcome was evaluated using retrograde labeling, histomorphometric analysis, and muscle force analysis. RESULTS All reconstructed groups showed successful regeneration with various levels of function. The negative control group showed minimal force measurements that were of no functional value. The fascicular shift provided sufficient guidance to overcome nerve defects, had higher (p < 0.1) motor neuron counts (1958.75 ± 657.21) than the sensory graft (1263.50 ± 538.90), and was equal to motor grafts (1490.43 ± 794.80) and mixed grafts (1720.00 ± 866.421). This tendency of improved motor regeneration was confirmed in all analyses. The mixed graft group was compared with the experimental group to investigate the influence of the potential damage induced by the fascicular shift distal to the repair site. However, none of the analyses revealed an impairment of nerve regeneration for both the tibial and common peroneal index muscles. CONCLUSIONS This study demonstrates that harvesting a transplant from the nerve segment distal to the injury site offers a mixed graft without causing additional donor-site morbidity. These grafts perform statistically better than a standard sensory graft in terms of motor recovery. The fascicular shift presents a novel method to reconstruct large proximal nerve defects, making it immensely attractive in brachial plexus reconstruction.

Multiuse of Disposable Microsurgical Instruments as a Cost-Efficient Alternative for Training and Research.

Microsurgery demands significant preclinical training, often hampered by the high costs of the required microsurgery instruments. We hypothesized that recently available disposable microsurgery instruments provide sufficient quality and significantly reduced costs. In a comparative analysis with standard reusable instruments, participants performed equally with both instrument sets and recommended the disposable instruments for microsurgery training and research applications.

Sunscreen compliance with regional clinical practice guidelines and product labeling standards in New Zealand.

INTRODUCTION For general practitioners, practice nurses and community pharmacists in New Zealand, a core duty is to educate patients about sun protection. We aimed to evaluate compliance of locally available sunscreens with regional clinical practice guidelines and sunscreen labelling standards, to assist clinicians in advising consumers on sunscreen selection. METHODS We audited all sunscreens available at two Auckland stores for three New Zealand sunscreen retailers. We then assessed compliance with accepted regional clinical practice guidelines for sun protection from the New Zealand Guidelines Group. We further assessed compliance with regional Australia/New Zealand consumer standards for sunscreen labelling. RESULTS All sunscreens satisfied clinical guidelines for broad-spectrum protection, and 99% of sunscreens met or exceeded clinical guidelines for minimal Sun Protection Factor. Compliance with regional standardized labelling guidelines is voluntary in New Zealand and 27% of audited sunscreens were not fully compliant with SPF labelling standards. DISCUSSION Sunscreens were generally compliant with clinical guidelines for minimal sun protection. However there was substantial noncompliance with regional recommendations for standardized sunscreen labelling. Primary health care clinicians should be aware that this labelling noncompliance may mislead patients into thinking some sunscreens offer more sun protection than they do. Mandatory compliance with the latest regional labelling standards would simplify sunscreen selection by New Zealand consumers. KEYWORDS Sunscreen; Sun Protection Factor; SPF; Skin Neoplasms; Melanoma; Skin Cancer Prevention.