Repair, protection and regeneration of peripheral nerve injury

Reading guide 1778Repair of long-segment peripheral nerve defects1779Bionic reconstruction of hand function after adult brachial plexus root avulsion1780Optimized design of regeneration material for the treatment of peripheral nerve injury1781Synergism of electroactive polymeric materials and electrical stimulation promotes peripheral nerve repair1783Schwann cell effect on peripheral nerve repair and regeneration .

Fat Embolism Syndrome in a Patient with Bilateral Tibial Fractures: Report of the Case and Review of the Literature

Background: Although the original clinical description of fat embolism syndrome (FES) dates from 1873, the condition remains a diagnostic challenge for modern clinicians. The syndrome is described as a serious consequence of fat emboli producing a distinct pattern of clinical symptoms and signs. It is mainly associated with fractures of the long-bones and the pelvis. The present paper describes the case of a trauma patient with bilateral tibial fractures that present the syndrome and highlights the importance of early identification and aggressive treatment of FES which is obligatory for the patient’s survival. Case Description: A 32 year-old man reached the hospital as a trauma call after a road traffic accident. Clinical examination was unremarkable with the only finding that the patient was unable to straight leg raise and weight bear. Both shins were painful and swollen at their middle third, while the left one was in varus and posterior displacement. Neurovascular status of both lower extremities was normal. Plain radiographic control (X-Rays) revealed an oblique right tibial fracture of the mid-shaft with a distal third fibular fracture and a comminuted fracture of the left tibia with a fracture of the fibula at the same level. The legs were immobilised on a splint and the decision was to treat the patient surgically. Within a few post admission hours the haemoglobin dropped by 2.9 mg/dL, however a source of active bleeding could not be allocated. The abdomen was soft and not tender in palpation and the central nervous system did not present any abnormalities. The following day the haemoglobin dropped but the new ultrasonography control did not reveal any free abdominal fluid. Both lower limbs were not compromised. The second post-injury day the patient went to theatre and the right tibia was stabilised with an antegrade nail (T2-Stryker) while the left one with an external fixation. During the reaming process the haemoglobin dropped to 7.1 gr/dL, so he was transfused with 3 blood units. Immediately after extubation, the patient desaturated on air and ABG values forced the anaesthetists to intubate him in recovery and place him in mechanical ventilation with high levels of positive end expiratory pressure (PEEP). Symptoms subsided rapidly and he was transferred to the IMU. Clinical image and CT scan were in favour of fat embolism syndrome. On the fifth post-operative day the patient was transferred back to ward and a week later he was discharged being completely free of symptoms. Clinical Relevance: Fat embolism syndrome is typically presented with the following triad: a) respiratory changes;b) neurologic abnormalities;c) petechial rash. These three constitute the major criteria described by Gurd and are pathognomonic for the condition. The patient—described in the present case report—developed progressively all those symptoms within the expected period of time. The FES is a well-known pathological condition that is well described in literature and should be familiar to those clinicians that manage trauma patients. Diagnosing the condition can be highly demanding since there are no laboratory investigations or radiographic imaging techniques specific for FES. Suspicion and diagnosis can be mainly placed based on the criteria described by Gurd, in 1970.

Using posterior part of the deltoid muscle as receptor and quality control with intra-operative electrophysiological examination in targeted muscle reinnervation for high-level upper extremity amputees

To the Editor:Targeted muscle reinnervation(TMR)is a surgical technique of multiple nerve transfers,providing a potential of improved intuitive prosthetic control via surface electromyography(sEMG)in the high-level upper extremity amputees.[1]However,there is a risk that some of the reinnervations might be unsuccessful,especially for the ulnar nerve.[2]Both the quality control of nerve stumps and the receptor are important factors for the surgery.Assessing the nerve stumps during the surgery and finding more muscles as receptor might address the problem.Biceps,triceps,and brachialis muscles were mostly chosen as receptors for reinnervation in the trans-humeral amputees.Pectoralis major and pectoralis minor were mostly chosen as receptors for reinnervation in the shoulder disarticulation patients.

Hand surgery in a new“hand-brain” era:change the hand,rebuild the brain

Amputated hand,and paralyzed hand,are diseases not on the conventional list of the hand surgery world,but now have gradually become the new direction for hand surgeons.A good example is the advancements in treating amputations after traumatic injury of the upper limb.Targeted muscle reinnervation combined with a highly functional bionic arm can greatly compensate for the missing part of the amputated arm[1],which in general satisfies the need for strength and dexterity in daily life.According to the classic cortical homunculus first drawn by Penfield,the hand area occupied nearly-one-third of the sensorimotor cortex[2].Thus,interventions with the hands enable the modulation of brain function,providing a solution for brain disorders through skillful utilization of brain plasticity.With the recent advancements in neuroscience and biomedical engineering technology,hand surgeons find themselves entering an era with a bigger performance stage than ever before.For paralyzed hand,the most common cause is central neurological diseases such as stroke or cerebral palsy,or paraplegia.Although it is more challenging since surgeons should balance spasticity and motor function at the same time,efforts have been made by hand surgeons around the world,such as hyper selective neurectomy,tendon lengthening or transfer to reduce the spasticity and reconstruct the motor function[3].Considering the fact that the number of patients with paralyzed hands is over 10 million,which far exceeds the traditional nerve injury entity,this area is the potential further direction of hand surgery.In this article,we will discuss the opportunities and pitfalls in the combination of hand surgery techniques and brain-computer-interface(BCI)in treating paralyzed hands from the perspective of hand surgery development.

Restoring After Central Nervous System Injuries:Neural Mechanisms and Translational Applications of Motor Recovery

Central nervous system(CNS)injuries,including stroke,traumatic brain injury,and spinal cord injury,are leading causes of long-term disability.It is estimated that more than half of the survivors of severe unilateral injury are unable to use the denervated limb.Previous studies have focused on neuroprotective interventions in the affected hemisphere to limit brain lesions and neurorepair measures to promote recovery.However,the ability to increase plasticity in the injured brain is restricted and difficult to improve.Therefore,over several decades,researchers have been prompted to enhance the compensation by the unaffected hemisphere.Animal experiments have revealed that regrowth of ipsilateral descending fibers from the unaffected hemisphere to denervated motor neurons plays a significant role in the restoration of motor function.In addition,several clinical treatments have been designed to restore ipsilateral motor control,including brain stimulation,nerve transfer surgery,and brain–computer interface systems.Here,we comprehensively review the neural mechanisms as well as translational applications of ipsilateral motor control upon rehabilitation after CNS injuries.

Neuroinflammation Mediates Faster Brachial Plexus Regeneration in Subjects with Cerebral Injury

Our previous investigation suggested that faster seventh cervical nerve(C7)regeneration occurs in patients with cerebral injury undergoing contralateral C7 transfer.This finding needed further verification,and the mechanism remained largely unknown.Here,Tinel’s test revealed faster C7 regeneration in patients with cerebral injury,which was further confirmed in mice by electrophysiological recordings and histological analysis.Furthermore,we identified an altered systemic inflammatory response that led to the transformation of macrophage polarization as a mechanism underlying the increased nerve regeneration in patients with cerebral injury.In mice,we showed that,as a contributing factor,serum amyloid protein A1(SAA1)promoted C7 regeneration and interfered with macrophage polarization in vivo.Our results indicate that altered inflammation promotes the regenerative capacity of the C7 nerve by altering macrophage behavior.SAA1 may be a therapeutic target to improve the recovery of injured peripheral nerves.

Vascular trauma： selected historical reflections from the western world

In the spirit of international exchanges of knowledge with colleagues from all over the world, who are interested in the care and treatment of vascular trauma, we offer selected historical reflections from the western world on vascular trauma. Whereas there are a number of key individuals and a variety of events that are important to us in our writing, we know essentially nothing about what is written by other cultures and, particularly, the Chinese. It is well recognized around the world that Chinese surgeons are among the first to be highly successful in re-plantation of severed extremities, repairing both injured arteries and veins. Also, we recognize that there are contributions in other parts of the world, which are not well known to us collectively. Contributions from the Arabic speaking part of the world come to mind because there is periodic brief reference. We offer our perspective hoping that there will be one or more Chinese surgeons who will offer us the benefit of sharing their perspective on important historical contribu- tions to the managing of vascular trauma outside of the western world, and, particularly, the English speaking literature. Once again, we encourage our colleagues in the Arabic speaking world to provide us with their perspective of the development and management of vascular trauma.

Surgical treatment of synovial-collagen disorders of the hand

Critical relationships between collagen and synovium exist and affect the function of the hand.Understanding these relationships enhances the ability to perform surgery including procedures addressing soft tissue and joint pathology.We present a series of surgical procedures based on this principle.