Nerve injuries of the upper extremity and hand

Muscle preservation in proximal nerve injuries: a current update

Optimal recovery of muscle function after proximal nerve injuries remains a complex and challenging problem. After a nerve injury, alterations in the affected muscles lead to atrophy, and later degeneration and replacement by fat-fibrous tissues. At present, several different strategies for the preservation of skeletal muscle have been reported, including various sets of physical exercises, muscle massage, physical methods (e.g. electrical stimulation, magnetic field and laser stimulation, low-intensity pulsed ultrasound), medicines (e.g. nutrients, natural and chemical agents, anti-inflammatory and antioxidants, hormones, enzymes and enzyme inhibitors), regenerative medicine (e.g. growth factors, stem cells and microbiota) and surgical procedures (e.g. supercharge end-to-side neurotization). The present review will focus on methods that aimed to minimize the damage to muscles after denervation based on our present knowledge.

Occupational Nerve Injuries due to Metallic Foreign Bodies: A Case Series of Eighteen Patients

Introduction

Peripheral nerve injuries (PNIs) remain an important health problem. PNIs mostly affect young men as this age group is mostly involved in road traffic accidents and other injuries at workplace. PNI can occur from foreign bodies like metal chips while working in industries using lathe machines. Among PNI's, injuries to the ulnar nerve, the brachial plexus and the median nerve are the most frequent lesions encountered.

Materials and methods

This presentation is on a series of 18 cases of nerve injuries among industrial workers located from finger level up to the arm excluding the brachial plexus due to metallic foreign bodies entering while operating lathe machines over a period of two years with patients being followed-up over a one year period.

Results

Mean age in this series was 31.3 years with age range 16-40 years and all were males. Two patients had more than one nerve involvement and one patient had associated vascular injury. All the patients showed functional improvement. Most common nerve injured was median nerve. Most common site for nerve injury was forearm. Combined lesions most commonly involved the ulnar and median nerves.

Conclusion

Social cost of traumatic peripheral nerve injuries is significant since it has a higher incidence in young, previously healthy, and economically active people.

Comparison of nerve versus tendon transfer for radial nerve palsy

OBJECTIVE

This study aims to investigate the choice of intervention time and operation mode between nerve and tendon transfer for the treatment of radial nerve palsy (RNP).

METHODS

46 RNP patients underwent nerve transfer (n = 22) and tendon transfer (n = 24). The intraoperative blood loss, main incision length, operation duration, and length of hospital stay and follow-up period of patients in these two groups were recorded and compared. The range of motion (ROM) of the elbow, wrist, fingers, and thumb, the hand grip and pinch strength, the Disabilities of Arm, Shoulder, and Hand (DASH) and the 36-Item Short Form Health Survey (SF-36) scores were measured and compared preoperatively and postoperatively between the two groups.

RESULTS

The ROM of thumb and the hand grip strength of patients in the nerve transfer group were greater than that in the tendon transfer (P < 0.05). Both of the two groups indicated significant improvements in the ROM of elbow, wrist, finger, thumb and the hand grip and pinch strength (P < 0.05) postoperatively. The DASH scores decreased significantly at 6 months (P < 0.05) and 12 months (P < 0.05) after surgery in both groups, while the postoperative SF-36 scores significantly increased (P < 0.05). There was no significant difference in postoperative DASH and SF-36 scores between the two groups (P > 0.05).

CONCLUSION

In summary, both nerve and tendon transfer techniques are effective treatments for RNP. Nerve transfer is particularly advantageous for early RNP, while tendon transfer is suitable for patients with radial nerve injury more than one year.

Nerve Tracing in Juvenile Rats: A Feasible Model for the Study of Brachial Plexus Birth Palsy and Cocontractions?

Brachial plexus birth injuries cause diminished motor function in the upper extremity. The most common sequel is internal rotation contracture. A number of these patients also suffer from cocontractions, preventing the use of an otherwise good passive range of motion in the shoulder. One theory behind the co-contracture problem is that injured nerve fibers grow into distal support tissue not corresponding to the proximal support tissue, resulting in reinnervation of the wrong muscle groups. To further elucidate this hypothesis, we used rat neonates to investigate a possible model for the study of cocontractions in brachial plexus birth injuries. Five-day-old rats were subjected to a crush injury to the C5-C6 roots. After a healing period of 4 weeks, the infraspinatus muscle was injected with Fluoro-Gold. A week later, the animals were perfused and spinal cords harvested and sectioned. Differences in the uptake of Fluoro-Gold and NeuN positive cells of between sides of the spinal cord were recorded. We found a larger amount of Fluoro-Gold positive cells on the uninjured side, while the injured side had positive cells dispersed over a longer area in the craniocaudal direction. Our findings indicate that the method can be used to trace Fluoro-Gold from muscle through a neuroma. Our results also indicate that a neuroma in continuity somewhat prevents the correct connection from being established between the motor neuron pool in the spinal cord and target muscle and that some neurons succumb to a crushing injury. We also present future research ideas.

Exploration of sensations evoked during electrical stimulation of the median nerve at the wrist level

Objective.Nerve rehabilitation following nerve injury or surgery at the wrist level is a lengthy process during which not only peripheral nerves regrow towards receptors and muscles, but also the brain undergoes plastic changes. As a result, at the time when nerves reach their targets, the brain might have already allocated some of the areas within the somatosensory cortex that originally processed hand signals to some other regions of the body. The aim of this study is to show that it is possible to evoke a variety of somatotopic sensations related to the hand while stimulating proximally to the injury, therefore, providing the brain with the relevant inputs from the hand regions affected by the nerve damage.Approach.This study included electrical stimulation of 28 able-bodied participants where an electrode that acted as a cathode was placed above the Median nerve at the wrist level. The parameters of electrical stimulation, amplitude, frequency, and pulse shape, were modulated within predefined ranges to evaluate their influence on the evoked sensations.Main results.Using this methodology, the participants reported a wide variety of somatotopic sensations from the hand regions distal to the stimulation electrode.Significance.Furthermore, to propose an accelerated stimulation tuning procedure that could be implemented in a clinical protocol and/or standalone device for providing meaningful sensations to the somatosensory cortex during nerve regeneration, we trained machine-learning techniques using the gathered data to predict the location/area, naturalness, and sensation type of the evoked sensations following different stimulation patterns.

Mechanisms, interventions at risk and clinical presentation of iatrogenic nerve lesions in trauma patients

BACKGROUND

Iatrogenic nerve lesions during surgical interventions are avoidable complications that may cause severe functional impairment. Hereby, awareness of physicians and knowledge of structures and interventions at risk is of utmost importance for prevention. As current literature is scarce, we evaluated all patients treated surgically due to peripheral nerve injuries in our specialized nerve center for the presence of iatrogenic nerve lesions.

METHODS

We evaluated a total of 5026 patients with peripheral nerve injuries treated over a time period of 8 years in our facility for the prevalence of iatrogenic nerve injuries, their clinical presentations, time to treatment, mechanisms and intraoperative findings on nerve continuity.

RESULTS

A total of 360 (6.1%) patients had an iatrogenic cause resulting in 380 injured nerves. 76.6% of these lesions affected the main branch of the injured nerve, which were mainly the radial (30.5%), peroneal (13.7%) and median nerve (10.3%). After a mean delay of 237 ± 344 days, patients presented 23.2% with a motor and 27.9% with a mixed sensory and motor deficit. 72.6% of lesions were in-continuity lesions. Main interventions at risk are displayed for every nerve, frequently concerning osteosyntheses but also patient positioning and anesthesiologic interventions.

DISCUSSION

Awareness of major surgical complications such as iatrogenic nerve injuries is important for surgeons. An often-seen trivialization or "watch and wait" strategy results in a huge delay for starting an adequate therapy. The high number of in-continuity lesions mainly in close proximity to osteosyntheses makes diagnosis and treatment planning a delicate challenge, especially due to the varying clinical presentations we found. Diagnostics and therapy should therefore be performed as early as possible in specialized centers capable of performing nerve repair as well as salvage therapies.

Primary Neurorraphy of the Frontotemporal Branch of the Facial Nerve in Pediatric Patients

LEVEL OF EVIDENCE

Level III-case-control study.

The Dynamics of Nerve Degeneration and Regeneration in a Healthy Milieu and in Diabetes

Appropriate animal models, mimicking conditions of both health and disease, are needed to understand not only the biology and the physiology of neurons and other cells under normal conditions but also under stress conditions, like nerve injuries and neuropathy. In such conditions, understanding how genes and different factors are activated through the well-orchestrated programs in neurons and other related cells is crucial. Knowledge about key players associated with nerve regeneration intended for axonal outgrowth, migration of Schwann cells with respect to suitable substrates, invasion of macrophages, appropriate conditioning of extracellular matrix, activation of fibroblasts, formation of endothelial cells and blood vessels, and activation of other players in healthy and diabetic conditions is relevant. Appropriate physical and chemical attractions and repulsions are needed for an optimal and directed regeneration and are investigated in various nerve injury and repair/reconstruction models using healthy and diabetic rat models with relevant blood glucose levels. Understanding dynamic processes constantly occurring in neuropathies, like diabetic neuropathy, with concomitant degeneration and regeneration, requires advanced technology and bioinformatics for an integrated view of the behavior of different cell types based on genomics, transcriptomics, proteomics, and imaging at different visualization levels. Single-cell-transcriptional profile analysis of different cells may reveal any heterogeneity among key players in peripheral nerves in health and disease.

Evaluation of Processed Nerve Allograft in Peripheral Nerve Surgery: A Systematic Review and Critical Appraisal

Peripheral nerve injuries cause substantial problems when not treated properly. A specific problem is reconstruction of nerve defects, which can be treated in different ways. This study aimed to systematically review whether processed nerve allograft (PNA) is justified in reconstruction of a nerve defect in patients after posttraumatic or iatrogenic peripheral nerve injury and to compare PNA with other established methods.

Methods

A systematic review with a focused question, PICO (patient, intervention, comparison, outcome) and constraints, was performed. A structured literature search, including several databases, was done to evaluate the existing evidence for outcomes and postoperative complications related to PNA. The certainty of evidence was classified according to Grading of Recommendations, Assessment, Development and Evaluations.

Results

No conclusions, concerning differences in outcome of nerve reconstruction using PNA compared with the use of nerve autograft or conduits, could be drawn. The level of certainty for all evaluated outcomes was very low (⊕◯◯◯). Most published studies lack a control group to patients treated with PNA; being only descriptive, making it difficult to compare PNA with established methods without substantial risk of bias. For studies including a control group, the scientific evidence was of very low certainty, due to a low number of included patients, and large, undefined loss of patients during follow-up, rendering a high risk of bias. Finally, the authors often had financial disclosures.

Conclusion

Properly conducted randomized controlled trial studies on the use of PNA in reconstruction of peripheral nerve injuries are needed to establish recommendations in clinical practice.

Traumatic peripheral nerve injuries: a classification proposal

BACKGROUND

Peripheral nerve injuries (PNIs) include several conditions in which one or more peripheral nerves are damaged. Trauma is one of the most common causes of PNIs and young people are particularly affected. They have a significant impact on patients' quality of life and on the healthcare system, while timing and type of surgical treatment are of the utmost importance to guarantee the most favorable functional recovery. To date, several different classifications of PNIs have been proposed, most of them focusing on just one or few aspects of these complex conditions, such as type of injury, anatomic situation, or prognostic factors. Current classifications do not enable us to have a complete view of this pathology, which includes diagnosis, treatment choice, and possible outcomes. This fragmentation sometimes leads to an ambiguous definition of PNIs and the impossibility of exchanging crucial information between different physicians and healthcare structures, which can create confusion in the choice of therapeutic strategies and timing of surgery.

MATERIALS

The authors retrospectively analyzed a group of 24 patients treated in their center and applied a new classification for PNI injuries. They chose (a) five injury-related factors, namely nerve involved, lesion site, nerve type (whether motor, sensory or mixed), surrounding tissues (whether soft tissues were involved or not), and lesion type-whether partial/in continuity or complete. An alphanumeric code was applied to each of these classes, and (b) four prognostic codes, related to age, timing, techniques, and comorbidities.

RESULTS

An alphanumeric code was produced, similar to that used in the AO classification of fractures.

CONCLUSIONS

The authors propose this novel classification for PNIs, with the main advantage to allow physicians to easily understand the characteristics of nerve lesions, severity, possibility of spontaneous recovery, onset of early complications, need for surgical treatment, and the best surgical approach.

LEVEL OF EVIDENCE

according to the Oxford 2011 level of evidence, level 2.

Bioprinted Schwann and Mesenchymal Stem Cell Co-Cultures for Enhanced Spatial Control of Neurite Outgrowth

Bioprinting nerve conduits supplemented with glial or stem cells is a promising approach to promote axonal regeneration in the injured nervous system. In this study, we examined the effects of different compositions of bioprinted fibrin hydrogels supplemented with Schwann cells and mesenchymal stem cells (MSCs) on cell viability, production of neurotrophic factors, and neurite outgrowth from adult sensory neurons. To reduce cell damage during bioprinting, we analyzed and optimized the shear stress magnitude and exposure time. The results demonstrated that fibrin hydrogel made from 9 mg/mL of fibrinogen and 50IE/mL of thrombin maintained the gel’s highest stability and cell viability. Gene transcription levels for neurotrophic factors were significantly higher in cultures containing Schwann cells. However, the amount of the secreted neurotrophic factors was similar in all co-cultures with the different ratios of Schwann cells and MSCs. By testing various co-culture combinations, we found that the number of Schwann cells can feasibly be reduced by half and still stimulate guided neurite outgrowth in a 3D-printed fibrin matrix. This study demonstrates that bioprinting can be used to develop nerve conduits with optimized cell compositions to guide axonal regeneration.

Hopeless Neuroma-The Neurotized Free Flap Tissue Augmentation as Salvage Therapy-A Concept and Clinical Demonstration

Therapy-resistant neuroma pain is a devastating condition for patients and surgeons. Although various methods are described to surgically deal with neuromas, some discontinuity and stump neuroma therapies have anatomical limitations. It is widely known that a neurotizable target for axon ingrowth is beneficial for dealing with neuromas. The nerve needs "something to do". Furthermore, sufficient soft tissue coverage plays a major role in sufficient neuroma therapy. We aimed, therefore, to demonstrate our approach for therapy of resistant neuromas with insufficient tissue coverage using free flaps, which are sensory neurotized via anatomical constant branches. The central idea is to provide a new target, a new "to do" for the painful mislead axons, as well as an augmentation of deficient soft tissues. As indication is key, we furthermore demonstrate clinical cases and common neurotizable workhorse flaps.

Peripheral Nerve Regeneration: Opportunities and Challenges

Peripheral nerve injury has detrimental effects on the quality of life for patients and is a worldwide issue with high rates of morbidity. Research on the molecular mechanisms of nerve injury, microsurgical techniques, and advances in stem cell research have led to substantial progress in the field of translational neurophysiology. Current research on peripheral nerve regeneration aims to accelerate peripheral nerve development through pluripotent stem cells and potential use of smart exosomes, pharmacological agents, and bioengineering of nerve conduits. In this article critically reviewed and summarized various methods used for peripheral nerve regeneration and highlight the opportunities and challenges that come along with these strategies.

Traumatic neuromas of peripheral nerves: Diagnosis, management and future perspectives

Traumatic neuromas are infrequent in clinical settings but are prevalent following trauma or surgery. A traumatic neuroma is not a true malignancy, rather, it is a hyperplastic, reparative nerve reaction after injury and typically manifests as a nodular mass. The most common clinical manifestations include painful hypersensitivity and the presence of a trigger point that causes neuralgic pain, which could seriously decrease the living standards of patients. While various studies are conducted aiming to improve current diagnosis and management strategies via the induction of emerging imaging tools and surgical or conservative treatment. However, researchers and clinicians have yet to reach a consensus regarding traumatic neuromas. In this review, we aim to start with the possible underlying mechanisms of traumatic neuromas, elaborate on the diagnosis, treatment, and prevention schemes, and discuss the current experiment models and advances in research for the future management of traumatic neuromas.

Additive Manufacturing of Polyhydroxyalkanoate-Based Blends Using Fused Deposition Modelling for the Development of Biomedical Devices

In the last few decades Additive Manufacturing has advanced and is becoming important for biomedical applications. In this study we look at a variety of biomedical devices including, bone implants, tooth implants, osteochondral tissue repair patches, general tissue repair patches, nerve guidance conduits (NGCs) and coronary artery stents to which fused deposition modelling (FDM) can be applied. We have proposed CAD designs for these devices and employed a cost-effective 3D printer to fabricate proof-of-concept prototypes. We highlight issues with current CAD design and slicing and suggest optimisations of more complex designs targeted towards biomedical applications. We demonstrate the ability to print patient specific implants from real CT scans and reconstruct missing structures by means of mirroring and mesh mixing. A blend of Polyhydroxyalkanoates (PHAs), a family of biocompatible and bioresorbable natural polymers and Poly(L-lactic acid) (PLLA), a known bioresorbable medical polymer is used. Our characterisation of the PLA/PHA filament suggest that its tensile properties might be useful to applications such as stents, NGCs, and bone scaffolds. In addition to this, the proof-of-concept work for other applications shows that FDM is very useful for a large variety of other soft tissue applications, however other more elastomeric MCL-PHAs need to be used.

Posttraumatic Trigeminal Neuropathic Pain in Association with Dental Implant Surgery

Posttraumatic trigeminal neuropathy in association with dental implant surgery is preventable, and this should be the emphasis for all clinicians considering this treatment for a patient. Once the nerve injury and posttraumatic neuropathy with or without pain ensues, there is very little the clinician can do to reverse it and the high pain and permanency of the neuropathy will have a significant functional and psychological impact on the patient. Immediate implant removal is required, and home check should be routine for all cases. International diagnostic criteria are available and should be implemented in everyday practice.

Automatic detection of abnormal hand gestures in patients with radial, ulnar, or median nerve injury using hand pose estimation

Background

Radial, ulnar, or median nerve injuries are common peripheral nerve injuries. They usually present specific abnormal signs on the hands as evidence for hand surgeons to diagnose. However, without specialized knowledge, it is difficult for primary healthcare providers to recognize the clinical meaning and the potential nerve injuries through the abnormalities, often leading to misdiagnosis. Developing technologies for automatically detecting abnormal hand gestures would assist general medical service practitioners with an early diagnosis and treatment.

Methods

Based on expert experience, we selected three hand gestures with predetermined features and rules as three independent binary classification tasks for abnormal gesture detection. Images from patients with unilateral radial, ulnar, or median nerve injuries and healthy volunteers were obtained using a smartphone. The landmark coordinates were extracted using Google MediaPipe Hands to calculate the features. The receiver operating characteristic curve was employed for feature selection. We compared the performance of rule-based models with logistic regression, support vector machine and of random forest machine learning models by evaluating the accuracy, sensitivity, and specificity.

Results

The study included 1,344 images, twenty-two patients, and thirty-four volunteers. In rule-based models, eight features were finally selected. The accuracy, sensitivity, and specificity were (1) 98.2, 91.7, and 99.0% for radial nerve injury detection; (2) 97.3, 83.3, and 99.0% for ulnar nerve injury detection; and (3) 96.4, 87.5, and 97.1% for median nerve injury detection, respectively. All machine learning models had accuracy above 95% and sensitivity ranging from 37.5 to 100%.

Conclusion

Our study provides a helpful tool for detecting abnormal gestures in radial, ulnar, or median nerve injuries with satisfying accuracy, sensitivity, and specificity. It confirms that hand pose estimation could automatically analyze and detect the abnormalities from images of these patients. It has the potential to be a simple and convenient screening method for primary healthcare and telemedicine application.

Efficacy of Nerve-Derived Hydrogels to Promote Axon Regeneration Is Influenced by the Method of Tissue Decellularization

Injuries to large peripheral nerves are often associated with tissue defects and require reconstruction using autologous nerve grafts, which have limited availability and result in donor site morbidity. Peripheral nerve-derived hydrogels could potentially supplement or even replace these grafts. In this study, three decellularization protocols based on the ionic detergents sodium dodecyl sulfate (P1) and sodium deoxycholate (P2), or the organic solvent tri-n-butyl phosphate (P3), were used to prepare hydrogels. All protocols resulted in significantly decreased amounts of genomic DNA, but the P2 hydrogel showed the best preservation of extracellular matrix proteins, cytokines, and chemokines, and reduced levels of sulfated glycosaminoglycans. In vitro P1 and P2 hydrogels supported Schwann cell viability, secretion of VEGF, and neurite outgrowth. Surgical repair of a 10 mm-long rat sciatic nerve gap was performed by implantation of tubular polycaprolactone conduits filled with hydrogels followed by analyses using diffusion tensor imaging and immunostaining for neuronal and glial markers. The results demonstrated that the P2 hydrogel considerably increased the number of axons and the distance of regeneration into the distal nerve stump. In summary, the method used to decellularize nerve tissue affects the efficacy of the resulting hydrogels to support regeneration after nerve injury.

Effects of 4-Aminopyridine on Combined Nerve and Muscle Injury and Bone Loss

PURPOSE

Musculoskeletal injuries are common, and peripheral nerve injury (PNI) causes significant muscle and bone loss within weeks. After PNI, 4-aminopyridine (4-AP) improves functional recovery and muscle atrophy. However, it is unknown whether 4-AP has any effect on isolated traumatic muscle injury and PNI-induced bone loss.

METHODS

A standardized crush injury was performed on the sciatic nerve and muscles in mice, and the mice were assigned to receive normal saline or 4-AP treatment daily for 21 days. The postinjury motor and sensory function recovery was assessed, injured muscles were processed for histomorphometry, and the tibial bone was scanned for bone density.

RESULTS

4-Aminopyridine significantly accelerated the postinjury motor and sensory function recovery, improved muscle histomorphometry, increased muscle satellite cell numbers, and shifted muscle fiber types after combined nerve and muscle injury. Importantly, the 4-AP treatment significantly reduced PNI-induced bone loss. In contrast, in the case of isolated muscle injury, 4-AP had no effect on functional recovery and bone density, but it improved muscle-specific histomorphometry to a limited extent.

CONCLUSIONS

These findings demonstrate the potential beneficial effects of 4-AP on the recovery of muscle morphology and bone density after combined muscle and nerve injury.

CLINICAL RELEVANCE

Nerve injuries frequently involve muscle and result in rapid muscle and bone atrophy. In this scenario, 4-AP, in addition to accelerating nerve functional recovery, might work as an adjunctive agent to improve the recovery of injured muscle and attenuate PNI-induced bone loss.

Cold sensitivity, functional disability and predicting factors after a repaired digital nerve injury

To investigate self-reported cold sensitivity and functional disability after a repaired digital nerve injury. We identified 3204 individuals operated with digital nerve repair in the Swedish national quality registry for hand surgery (HAKIR). Patient-reported symptoms, including cold sensitivity and perceived disability, were examined using two questionnaires (HQ-8 and QuickDASH), three and 12 months postoperatively. Patients with diabetes (n = 48; 3%) were identified in the Swedish National Diabetes Register (NDR). Cold sensitivity (scored 0–100) was the most prominent symptom among 1553 included individuals (998 men, 555 women; median age 41 [IQR 27–54] years). In the regression analysis, flexor tendon injury, hand fracture and injury to multiple structures predicted worsened cold sensitivity (6.9, 15.5 and 25.0 points; p = 0.005, 0.046 and < 0.001) at 12 months. Individuals with moderate (30–70) and severe (> 70) cold sensitivity had higher QuickDASH scores at three and 12 months postoperatively than individuals with mild cold sensitivity (6.0 and 5.5; 19.8 and 21.0 points; p = 0.001). Flexor tendon injury, injuries to multiple structures and diabetes had significant effect on QuickDASH scores at three, but not at 12, months postoperatively. Cold sensitivity is common after a digital nerve repair and impacts self-reported disability. A concomitant injury, particularly multiple injuries, predicts postoperative cold sensitivity.

Trigeminal Traumatic Neuroma: a Comprehensive Review of the Literature Based On a Rare Case

PURPOSE OF REVIEW

Traumatic neuromas in general, and trigeminal traumatic neuromas in particular, are relatively rare entities originating from a damage to a corresponding nerve or its branches. This manuscript is a comprehensive review of the literature on trigeminal traumatic neuromas based on an interesting and challenging case of bilateral intraoral lesions.

RECENT FINDINGS

The diagnosis for this patient was bilateral trigeminal traumatic neuromas. It is possible that these patients have a genetic predisposition to the development of these lesions. It is a neuropathic pain condition and may mimic dental and other trigeminal pain entities. Topical treatment with lidocaine gel, utilizing a custom-made neurosensory stent, rendered the patient significant and sustained pain relief. Trigeminal traumatic neuromas present a diagnostic challenge even to a seasoned clinician, due to the complex clinical features that may mimic other entities. Topical medications such as local anesthetics may be a good viable alternative to systemic medications to manage the pain associated with the condition. Early identification of the lesion and the associated pain helps in the succinct management of symptomatic trigeminal traumatic neuromas.

Surgically Treated Neuroma in Upper Extremity: Patient Characteristics and Factors Influencing Outcome of Surgery

Neuroma formation occurs after inappropriately or untreated nerve injuries. Patients surgically treated for neuroma were characterized and factors influencing outcome evaluated.

Incidental Median Nerve Injury in the Hand by a High-Speed Drill

Traumatic injuries of the peripheral nerves can be easily overlooked in the emergency department. In these cases, extensive knowledge of anatomy, a high index of suspicion and correct evaluation of neurological status could maintain the proper diagnosis.

Median nerve injury in the region of the hand is commonly due to glass material. However, extremely rare, other causes of injury, such as pieces of wood, acupuncture needle-fracture bodies, metallic foreign bodies, and migration of K-wires, have been reported. In the current report, a case of median nerve injury in a 35-year-old man treated with a high-speed drill was reported to my knowledge for the first time in the current literature. Early and correct diagnosis for nerve injury is crucial for improved functional outcomes.

Effects of Photobiomodulation Therapy (LED 630 nm) on Muscle and Nerve Histomorphometry after Axonotmesis

Peripheral injuries constitute a substantial clinical problem with unsatisfactory treatment. The study's objective was to analyze the effects of photobiomodulation therapy (PBMT) on median nerve regeneration and muscle recovery after axonotmesis. Twenty-four rats were randomized into three groups: control (CG), injury (IG), and LED therapy (LEDG). A 630 ± 20 nm (300-mW) LED was placed in contact with the skin. One point over the injury site was irradiated for 30 s, delivering 9 J (9 J cm-2 ). PBMT irradiation was performed once daily for 5 days followed by two-day interval and then more five consecutive days of treatment. Proximal and distal segments of the nerve and flexors muscles were removed for histomorphometric analysis using H&E staining for muscles and osmium tetroxide for nerves. The myelinated fiber and axon diameter and the myelin sheath thickness were greater in the proximal and distal nerve segments in the LEDG compared to the IG (P ≤ 0.05). The number of myelinated fibers was greater in the distal segment of the LEDG (P ≤ 0.05). The area, circumference, and diameter of the muscle fibers were larger in the LEDG than in the IG (P ≤ 0.05). The PBMT protocol used favored axonal regeneration and muscle recovery.

[Neuropathic Pain - Differential Diagnosis and Treatment from the Hand Surgeon's Perspective]

Neuropathic Pain - Differential Diagnosis and Treatment from the Hand Surgeon's Perspective Abstract. Neuropathic pain of the wrist and hand can be caused by a multitude of pathologies, such as trauma, iatrogenic damage, local peripheral nerve compression, nerve tumors and systemic diseases. Neuropathic pain can lead to chronification and disability, severely affecting the patients' quality of life and the ability to work. A precise diagnosis is the key to an adequate therapy with satisfactory functional results. An interdisciplinary and multimodal approach is a prerequisite when treating neuropathic pain. This review article provides an insight into the diagnosis and therapy of pathologies associated with neuropathic pain of the wrist and hand.

Injury-Induced HSP27 Expression in Peripheral Nervous Tissue Is Not Associated with Any Alteration in Axonal Outgrowth after Immediate or Delayed Nerve Repair

We investigated injury-induced heat shock protein 27 (HSP27) expression and its association to axonal outgrowth after injury and different nerve repair models in healthy Wistar and diabetic Goto-Kakizaki rats. By immunohistochemistry, expression of HSP27 in sciatic nerves and DRG and axonal outgrowth (neurofilaments) in sciatic nerves were analyzed after no, immediate, and delayed (7-day delay) nerve repairs (7- or 14-day follow-up). An increased HSP27 expression in nerves and in DRG at the uninjured side was associated with diabetes. HSP27 expression in nerves and in DRG increased substantially after the nerve injuries, being higher at the site where axons and Schwann cells interacted. Regression analysis indicated a positive influence of immediate nerve repair compared to an unrepaired injury, but a shortly delayed nerve repair had no impact on axonal outgrowth. Diabetes was associated with a decreased axonal outgrowth. The increased expression of HSP27 in sciatic nerve and DRG did not influence axonal outgrowth. Injured sciatic nerves should appropriately be repaired in healthy and diabetic rats, but a short delay does not influence axonal outgrowth. HSP27 expression in sciatic nerve or DRG, despite an increase after nerve injury with or without a repair, is not associated with any alteration in axonal outgrowth.

Iatrogenic peripheral nerve injury: a guide to management for the orthopaedic limb surgeon

Nerves may be inadvertently injured during trauma surgery due to distorted anatomy, traction applied to a limb, soft tissue retraction, by power tools, instrumentation and from compartment syndrome. Elective orthopaedic surgery has additional risks of joint dislocation for arthroplasty surgery, limb lengthening, thermal injury from cement and direct injury from peripheral nerve blocks.The true incidence is unknown, and many cases are diagnosed as neurapraxia with the expectation of a full and timely recovery without the need for intervention. The incorrect assignation of a neurapraxia diagnosis may delay treatment for a higher grade of injury and in addition fails to recognize that a diagnosis of neurapraxia should be made with caution and a commitment to regular clinical review. Untreated, a neurapraxia can deteriorate and result in axonopathy. The failure to promptly diagnose such a nerve injury and instigate treatment may result in further deterioration and expose the clinician to medicolegal challenge.The focus of this review is to raise awareness of iatrogenic peripheral nerve injuries in orthopaedic limb surgery, the importance of regular clinical examination, the role of investigations, timing and nature of interventions and also to provide a guide to when onward referral to a specialist peripheral nerve injury unit is recommended. Cite this article: EFORT Open Rev 2021;6:607-617. DOI: 10.1302/2058-5241.6.200123.

'EngNT' - Engineering live neural tissue for nerve replacement

Peripheral nerve injury can result in severe long-term disability and current clinical approaches for repairing large gaps rely on the nerve autograft. Engineered Neural Tissue (EngNT) has been developed to provide living aligned therapeutic cells in a stabilised collagen hydrogel, mimicking the key features of the autograft. This Perspective article will introduce the field and discuss the current stage of translation, highlighting the key opportunities for commercial and clinical development.

Influence of aging, disease, exercise, and injury on human hand movements: A systematic review

The human hand is a versatile organ that performs a variety of activities in daily life. The coordination of digits allows them to deal with objects of various sizes and shapes with an appropriate range of motions (ROM). A systematic literature review was performed to identify the clinical and non-clinical factors which affected the normal ROM, grip strength (GS), and dexterity of hand. The overall outcomes of the systematic review showed that: the performance of the individual declined as the age progressed; the performance of the dominant hand (DH) of an individual was better compared to his/her non-dominant hand (NDH); the tasks performed by a healthy hand was more efficient compared to a diseased one; appropriate rehabilitation programs/exercise techniques after a disease or injury improved the ROM, GS, and dexterity of hand post-surgery on par to a healthy hand.

Gold and Cobalt Oxide Nanoparticles Modified Poly-Propylene Poly-Ethylene Glycol Membranes in Poly (ε-Caprolactone) Conduits Enhance Nerve Regeneration in the Sciatic Nerve of Healthy Rats

Reconstruction of nerve defects is a clinical challenge. Autologous nerve grafts as the gold standard treatment may result in an incomplete restoration of extremity function. Biosynthetic nerve conduits are studied widely, but still have limitations. Here, we reconstructed a 10 mm sciatic nerve defect in healthy rats and analyzed nerve regeneration in poly (ε-caprolactone) (PCL) conduits longitudinally divided by gold (Au) and gold-cobalt oxide (AuCoO) nanoparticles embedded in poly-propylene poly-ethylene glycol (PPEG) membranes (AuPPEG or AuCoOPPEG) and compared it with unmodified PPEG-membrane and hollow PCL conduits. After 21 days, we detected significantly better axonal outgrowth, together with higher numbers of activated Schwann cells (ATF3-labelled) and higher HSP27 expression, in reconstructed sciatic nerve and in corresponding dorsal root ganglia (DRG) in the AuPPEG and AuCoOPPEG groups; whereas the number of apoptotic Schwann cells (cleaved caspase 3-labelled) was significantly lower. Furthermore, numbers of activated and apoptotic Schwann cells in the regenerative matrix correlated with axonal outgrowth, whereas HSP27 expression in the regenerative matrix and in DRGs did not show any correlation with axonal outgrowth. We conclude that gold and cobalt-oxide nanoparticle modified membranes in conduits improve axonal outgrowth and increase the regenerative performance of conduits after nerve reconstruction.

Evaluation of postoperative outcomes in patients following multi-level surgical reconstructions with the use Avive™ soft tissue membrane on nerve after traumatic injury of the upper extremity and lower extremity

Background

Treatment of patients with traumatic axonotmesis presents challenges. Processed human umbilical cord membrane has been recently developed with improved handling and resorption time compared to other amniotic membrane wraps, and may be beneficial in nerve reconstruction. This study evaluates postoperative outcomes after traumatic peripheral nerve injury after placement of commercially available processed human umbilical cord membrane.

Methods

We performed a prospective, single-center pilot study of patients undergoing multi-level surgical reconstruction for exposed, non-transected peripheral nerve. Functional outcomes including pain, range of motion, pinch and grip strength, and the QuickDASH and SF-36 patient-reported outcome measures were recorded, when possible, at the 1-week and 3, 6, and 9 months postop visit. One-tailed paired t-tests were performed to evaluate outcome improvement at final follow-up.

Results

Twenty patients had processed human umbilical cord membrane placement without surgical complications. Mean follow-up was 7.5 months (range: 3-10 months) and mean age was 39 years (range: 15-65). Twelve (67%) patients were male, and the majority of placement sites were in the upper extremity (85%). Mean preoperative visual analog scale pain score was significantly reduced at most recent follow-up, as were QuickDASH scores. All patients had improved functional outcomes at the 9-month follow-up, and SF-36 outcomes at 9 months showed improvement across all dimensions.

Conclusion

This study indicates that processed human umbilical cord membrane may be a useful adjunct in nerve surgery with noted improvements in postoperative function, pain, and patient-reported outcome measures. Future studies are needed to assess long-term outcomes after traumatic nerve injury treated with processed human umbilical cord membrane.

Dorsal Coaptation for the Treatment of Digital Neuroma

PURPOSE

The formation of a symptomatic neuroma after digital tip amputation presents a vexing problem. There is currently no procedure that completely and consistently prevents hypersensitive neuroma formation. This report presents the results of a technique designed to limit axon regeneration and mechanical irritation by neuroma excision, dorsal transposition, and coaptation with the corresponding digital nerve.

METHODS

A retrospective chart review was conducted to assess the effectiveness of neuroma excision with dorsal transposition and epineurial coaptation for postamputation symptomatic digital neuromas. Neuromas were excised using a midlateral fish-mouth incision. Digital nerves were mobilized to the dorsum of the digital tip and coapted using 9-0 nylon epineurial suture. The procedure was modified to salvage viable fingernails or to avoid excessive tension. Mass et al's criteria system was used to evaluate effectiveness.

RESULTS

Twenty-four patients with painful neuromas of the radial and ulnar digital nerves after traumatic amputation were included. Thirty-two digits underwent dorsal coaptation. This procedure was associated with a result considered good or excellent in 28 of 32 digits. Twenty-seven of 32 digits registered no pain or stump anesthesia after dorsal coaptation. Twenty-five of 32 digits demonstrated no interference with activities of daily living. Twenty-one of 24 patients returned to work.

CONCLUSIONS

Neuroma excision with dorsal transposition and epineurial coaptation is an effective treatment for postamputation symptomatic digital neuroma.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Nanohydroxyapatite as a Biomaterial for Peripheral Nerve Regeneration after Mechanical Damage-In Vitro Study

Hydroxyapatite has been used in medicine for many years as a biomaterial or a cover for other biomaterials in orthopedics and dentistry. This study characterized the physicochemical properties (structure, particle size and morphology, surface properties) of Li⁺- and Li⁺/Eu³⁺-doped nanohydroxyapatite obtained using the wet chemistry method. The potential regenerative properties against neurite damage in cultures of neuron-like cells (SH-SY5Y and PC12 after differentiation) were also studied. The effect of nanohydroxyapatite (nHAp) on the induction of repair processes in cell cultures was assessed in tests of metabolic activity, the level of free oxygen radicals and nitric oxide, and the average length of neurites. The study showed that nanohydroxyapatite influences the increase in mitochondrial activity, which is correlated with the increase in the length of neurites. It has been shown that the doping of nanohydroxyapatite with Eu³⁺ ions enhances the antioxidant properties of the tested nanohydroxyapatite. These basic studies indicate its potential application in the treatment of neurite damage. These studies should be continued in primary neuronal cultures and then with in vivo models.

Finite Element Analysis of Glucose Diffusivity in Cellulose Nanofibril Peripheral Nerve Conduits

Peripheral neuropathy arising from physical trauma is estimated to afflict 20 million people in the United States alone. In one common surgical intervention, neural conduits are placed over the nerve stumps to bridge the gap and create a microenvironment conducive to regeneration. It has been proposed that a biocompatible material such as cellulose nanofiber may serve as a viable conduit material, providing a non-inflammatory and mechanically stable system. Preliminary studies have shown that cellulose nanofiber conduits successfully aid neural regeneration and further, that the dimensions of the conduit relative to the nerve gap have an impact on efficacy in murine models. It has been hypothesized that the reliance of regeneration upon the physical dimensions of the conduit may be related to modified modes of diffusion and/or distances of key cellular nutrients and waste metabolites to/from the injury site. The present work investigates the concentration profile of glucose within the conduit via finite element analysis as a function of the physical dimensions of the conduit. It was determined that the magnitude of glucose diffusion was greater through the conduit walls than through the luminal space between the nerve and the inner wall of the conduit, and that as such radial diffusion is dominant over axial diffusion.

Safety and efficacy of a nerve matrix membrane as a collagen nerve wrapping: a randomized, single-blind, multicenter clinical trial

A new nerve matrix membrane derived from decellularized porcine nerves has been shown to retain the major extracellular matrix components, and to be effective in preventing adhesion between the nerve anastomosis sites and the surrounding tissues in a rat sciatic nerve transection model, thereby enhancing regeneration of the nerve. The effectiveness of the membrane may be attributed to its various bioactive components. In this prospective, randomized, single-blind, parallel-controlled multicenter clinical trial, we compared the safety and efficacy of the new nerve matrix membrane with a previously approved bovine tendon-derived type I collagen nerve wrapping. A total of 120 patients with peripheral nerve injury were recruited from Beijing Jishuitan Hospital, The First Bethune Hospital of Jilin University, and Yantai Yuhuangding Hospital, China. The patients were randomly assigned to undergo end-to-end and tension-free neurorrhaphy with nerve matrix membrane (n = 60, 52 male, 8 female, mean age 41.34 years, experimental group) or tendon-derived collagen nerve wrapping (n = 60, 42 male, 18 female, mean age 40.17 years, control group). Patients were followed-up at 14 ± 5, 30 ± 7, 90 ± 10 and 180 ± 20 days after the operation. Safety evaluation included analyses of local and systemic reactions, related laboratory tests, and adverse reactions. Efficacy evaluation included a static 2-point discrimination test, a moving 2-point discrimination test, and a Semmes–Weinstein monofilament examination. Sensory nerve function was evaluated with the British Medical Research Council Scale and Semmes–Weinstein monofilament examination. The ratio (percentage) of patients with excellent to good results in sensory nerve recovery 180 ± 20 days after the treatment was used as the primary effectiveness index. The percentages of patients with excellent to good results in the experimental and control groups were 98.00% and 94.44%, respectively, with no significant difference between the two groups. There were no significant differences in the results of routine blood tests, liver and renal function tests, coagulation function tests, or immunoglobulin tests at 14 and 180 days postoperatively between the two groups. These findings suggest that the novel nerve matrix membrane is similar in efficacy to the commercially-available bovine-derived collagen membrane in the repair of peripheral nerve injury, and it may therefore serve as an alternative in the clinical setting. The clinical trial was approved by the Institutional Ethics Committee of Beijing Jishuitan Hospital, China (approval No. 20160902) on October 8, 2016, the Institutional Ethics Committee of the First Bethune Hospital of Jilin University, China (approval No. 160518-088) on December 14, 2016, and the Institutional Ethics Committee of Yantai Yuhuangding Hospital, China (approval No. 2016-10-01) on December 9, 2016. The clinical trial was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR2000033324) on May 28, 2020.

Factors affecting the final outcomes after reconstruction of the median and ulnar nerve at the level of the forearm: Analysis of 41 patients

BACKGROUND

Upper extremity injuries have a significant impact on social and professional life. They represent about 10% of visits to emergency departments. Nerve lacerations are one of the biggest problem because loss of innervation results in muscle atrophy, decreased sensibility, and therefore permanent dysfunction. Appropriate treatment is very important for patients to regain function.

MATERIALS AND METHODS

The study included 41 patients, 30 men and 11 women who underwent nerve repair surgery in the middle and distal forearm level in the years 2001-2017. The patients' age ranged from 9 to 73 years with an average of 37 years. They were divided into 3 groups with repaired median, ulnar and both nerves. We determined time from injury to nerve repair, assessed sensitivity in index and little finger with a two-point discriminator, and muscle strength by measuring adduction of the little finger and palmar abduction of the thumb.Results were rated based on Medical Research Council Scale (MRC). In addition, general hand disability was assessed according to the Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH).

RESULTS

There was a statistically significant (p = 0.0197), positive correlation (r > 0) between the period from injury to surgery and the DASH score, and statistically significant difference (p = 0.0001) in return of muscular function between groups with median, ulnar and both nerves injury. Also correlation between patients age and score of DASH was statistically significant (p = 0.0140) with positive correlation (r > 0). There was no statistically significant difference in the return of sensitivity (p = 0.4337) and the DASH score (p = 0.3831) between these three groups.

CONCLUSIONS

Patients with shorter time from injury to repair and at a younger age had better DASH results. The median nerve had the best motor function between the groups. There was no difference in sensitivity or DASH scores between groups.

Chronic neuropathic pain after traumatic peripheral nerve injuries in the upper extremity: prevalence, demographic and surgical determinants, impact on health and on pain medication

Background and aims Aside from the long term side effects of a nerve injury in the upper extremity with devastating consequences there is often the problem of chronic neuropathic pain. The studies concerning the prevalence of persistent pain of neuropathic origin after peripheral nerve injuries are sparse. The prevalence and risk factors associated with chronic neuropathic pain after nerve injuries in the upper extremity were assessed. Methods A standardized data collection template was employed prospectively and retrospectively for all patients with traumatic nerve injuries accepted at the Hand Surgery Department, Uppsala, Sweden between 2010 and 2018. The template included demographic data, pain diagnosis, type of injured nerve, level of injury, date of the lesion and repair, type of procedure, reoperation, time since the procedure, S-LANSS questionnaire (Self report-Leeds Assessment of Neuropathic Symptoms and Signs), RAND-36 (Item short form health survey), QuickDASH (Disability of Shoulder, Arm and Hand) and additional questionnaires concerned medication, pain intensity were sent to 1,051 patients with nerve injuries. Partial proportional odds models were used to investigate the association between persistent pain and potential predictors. Results More than half of the patients undergoing a surgical procedure developed persistent pain. Prevalence of neuropathic pain was 73% of the patients with pain (S-LANSS ≥ 12 or more). Multivariate analysis indicated that injury of a major nerve OR 1.6 (p = 0.013), years from surgery OR 0.91 (p = 0.01), younger age OR 0.7 (p < 0.001), were the main factors for predicting pain after surgery. The type of the nerve injured was the strongest predictor for chronic pain with major nerves associated with more pain (p = 0.019). Conclusions A high prevalence of chronic pain and neuropathic pain with a negative impact on quality of life and disability were found in patients after traumatic nerve injury. Major nerve injury, younger age and less time from surgery were predictors for chronic pain.

Modification of tubular chitosan-based peripheral nerve implants: applications for simple or more complex approaches

Surgical treatment of peripheral nerve injuries is still a major challenge in human clinic. Up to now, none of the well-developed microsurgical treatment options is able to guarantee a complete restoration of nerve function. This restriction is also effective for novel clinically approved artificial nerve guides. In this review, we compare surgical repair techniques primarily for digital nerve injuries reported with relatively high prevalence to be valuable attempts in clinical digital nerve repair and point out their advantages and shortcomings. We furthermore discuss the use of artificial nerve grafts with a focus on chitosan-based nerve guides, for which our own studies contributed to their approval for clinical use. In the second part of this review, very recent future perspectives for the enhancement of tubular (commonly hollow) nerve guides are discussed in terms of their clinical translatability and ability to form three-dimensional constructs that biomimick the natural nerve structure. This includes materials that have already shown their beneficial potential in in vivo studies like fibrous intraluminal guidance structures, hydrogels, growth factors, and approaches of cell transplantation. Additionally, we highlight upcoming future perspectives comprising co-application of stem cell secretome. From our overview, we conclude that already simple attempts are highly effective to increase the regeneration supporting properties of nerve guides in experimental studies. But for bringing nerve repair with bioartificial nerve grafts to the next level, e.g. repair of defects > 3 cm in human patients, more complex intraluminal guidance structures such as innovatively manufactured hydrogels and likely supplementation of stem cells or their secretome for therapeutic purposes may represent promising future perspectives.

Recent Findings on the Effects of Pharmacological Agents on the Nerve Regeneration after Peripheral Nerve Injury

Peripheral nerve injuries (PNIs) are accompanied with neuropathic pain and functional disability. Despite improvements in surgical repair techniques in recent years, the functional recovery is yet unsatisfied. Indeed a successful nerve repair depends not only on the surgical strategy but also on the cellular and molecular mechanisms involved in traumatic nerve injury. In contrast to all strategies suggested for nerve repair, pharmacotherapy is a cheap, accessible and non-invasive treatment that can be used immediately after nerve injury. This study aimed to review the effects of some pharmacological agents on the nerve regeneration after traumatic PNI evaluated by functional, histological and electrophysiological assessments. In addition, some cellular and molecular mechanisms responsible for their therapeutic actions, restricted to neural tissue, are suggested. These findings can not only help to find better strategies for peripheral nerve repair, but also to identify the neuropathic effects of various medications and their mechanisms of action.

Cold intolerance and neuropathic pain after peripheral nerve injury in upper extremity

Cold intolerance and pain can be a substantial problem in patients with peripheral nerve injury. We aimed at investigating the relationships among sensory recovery, cold intolerance, and neuropathic pain in patients affected by upper limb peripheral nerve injury (Sunderland type V) treated with microsurgical repair, followed by early sensory re-education. In a cross-sectional clinical study, 100 patients (male/female 81/19; age 40.5 ± 14.8 years and follow-up 17 ± 5 months, mean ± SD), with microsurgical nerve repair and reconstruction in the upper extremity and subsequent early sensory re-education, were evaluated, using Cold Intolerance Symptoms Severity questionnaire-Italian version (CISS-it, cut-off pathology >30/100 points), CISS questionnaire-12 item version (CISS-12, 0-46 points-grouping: healthy that means no cold intolerance [0-14], mild [15-24], moderate [25-34], severe [35-42], very severe [43-46] cold intolerance), probability of neuropathic pain (DouleurNeuropathique-4; [DN4] 4/10), deep and superficial sensibility, tactile threshold (monofilaments), and two-point discrimination (cutoff S2; Medical Research Council scale for sensory function; [MRC-scale]). A high CISS score is associated with possible neuropathic pain (DN4 ≥ 4). Both a low CISS-it score (ie, < 30) and DN4 < 4 is associated with good sensory recovery (MRC ≥ 2). In conclusion patients affected by upper limb peripheral nerve injuries with higher CISS scores more often suffer from cold intolerance and neuropathic pain, and the better their sensory recovery is, the less likely they are to suffer from cold intolerance and neuropathic pain.

Brachial Plexus Injuries in Sport Medicine: Clinical Evaluation, Diagnostic Approaches, Treatment Options, and Rehabilitative Interventions

The brachial plexus represents a complex anatomical structure in the upper limb. This "network" of peripheral nerves permits the rearrangement of motor efferent fibers, coming from different spinal nerves, in several terminal branches directed to upper limb muscles. Moreover, afferent information coming from different cutaneous regions in upper limb are sorted in different spinal nerves through the brachial plexus. Severe brachial plexus injuries are a rare clinical condition in the general population and in sport medicine, but with dramatic consequences on the motor and sensory functions of the upper limb. In some sports, like martial arts, milder injuries of the brachial plexus can occur, with transient symptoms and with a full recovery. Clinical evaluation represents the cornerstone in the assessment of the athletes with brachial plexus injuries. Electrodiagnostic studies and imaging techniques, like magnetic resonance and high-frequency ultrasound, could be useful to localize the lesion and to define an appropriate treatment and a functional prognosis. Several conservative and surgical techniques could be applied, and multidisciplinary rehabilitative programs could be performed to guide the athlete toward the recovery of the highest functional level, according to the type of injury.

Radial Nerve Palsy After Intercondylar Distal Humerus Fracture: A Case Report

CASE

A 30-year-old man sustained an injury to the right elbow after a fall from a bike. On clinical examination, he had preoperative radial nerve palsy with radiological diagnosis of the intercondylar distal humerus fracture. Intraoperatively, the patient had the radial nerve entrapped between the proximal metaphyseal fragment and distal lateral condyle of the humerus.

CONCLUSION

Preoperative radial nerve palsy associated with the intercondylar distal humerus fracture is very rare. Fractures with the significant anterolateral displacement of the proximal metaphyseal fracture segment may entrap the course of the radial nerve in the anterior compartment of the distal humerus and thus manifest as radial nerve palsy.

Beneficial effects of fish oil enriched in omega-3 fatty acids on the development and maintenance of neuropathic pain

OBJECTIVE

The aim of this work was to assess the preventive effect of an eicosapentaenoic acid/docosahexaenoic acid-concentrate fish oil on neuropathic pain development and regenerative features of sciatic nerve in rats.

METHODS

In the present study, rats with chronic constriction injury (CCI) of the sciatic nerve and sham-operated ones received fish oil enriched in omega-3 fatty acids (0.36 or 0.72 g/kg per day, oral) or saline solution for 21 days, with thermal hyperalgesia and mechanical allodynia being assessed before and 3, 7, 14 and 21 days after injury.

KEY FINDINGS

Fish oil enriched in omega-3 fatty acids (0.72 g/kg) reversed thermal hyperalgesia and significantly reduced mechanical allodynia. In addition, ω-3 treatment (0.72 g/kg) promoted the recovery of the Sciatic Functional Index as well as restored axonal density and morphology, without the formation of neuroma in the injured sciatic nerves after 21 days.

CONCLUSION

We conclude that the fish oil enriched in omega-3 fatty acids administration relieves thermal hyperalgesia and mechanical allodynia effectively and also enhances the recovery process in rats with CCI of the sciatic nerve. These findings might contribute to new therapeutic approaches including omega-3 fatty acids in neuropathic pain treatment.

Ulnar Nerve Injury and Froment's Test: A Case Report

Traumatic, peripheral nerve injuries can be easily missed in the emergency department. The attending physician needs to maintain a high index of suspicion when reviewing patients with extremity injuries.

We present a case of a stable, 28-year-old male sustaining penetrating trauma to his right forearm with resultant, isolated ulnar nerve transection. Clinical findings and related anatomy are discussed pertaining to this patient's injury, with specific reference to Froment's test. This is a useful clinical adjunct when reviewing potential ulnar nerve injuries, demonstrating disruption of specific motor innervation to the thumb when such pathology exists. As a result, compensatory hyperflexion occurs with attempted thumb adduction, due to intact median nerve innervation of flexor pollicis longus. Early recognition of this pathology, whether isolated or concomitant, allows for early appropriate referral and improved patient outcomes.

Isolated musculocutaneous neuropathy: a case report

OBJECTIVE

To present the diagnostic and clinical features of musculocutaneous neuropathy, propose possible conservative management strategies, and create awareness of this rare condition.

CASE PRESENTATION

We present the case of a 24-year old competitive soccer athlete, who sought care for an unrelated lower extremity complaint. Upon examination, significant wasting of the right biceps was noted. The patient reported right arm pain and weakness that began six months prior, following a long sleep with his arm beneath him. Neurological examination revealed an absent deep tendon reflex of C5 on the right, diminished sensation on the right anterolateral forearm, and significant weakness in muscle testing of the biceps brachii on the right. The patient was referred to a neurologist to confirm suspicion of a musculocutaneous nerve injury. Electromyography and magnetic resonance imaging confirmed the diagnosis of musculocutaneous neuropathy and ruled out other differential diagnoses. The patient is currently awaiting confirmation to determine if he is a surgical candidate for a nerve transfer.

SUMMARY

Musculocutaneous neuropathy is a rare condition. Recognition of the clinical presentation of this condition is important for early diagnosis and prompt intervention.

Patient satisfaction and outcomes of partial wrist denervation in inflammatory arthritis

INTRODUCTION

Inflammatory arthritis frequently affects the wrist, resulting in pain and disability. This study aims to investigate the long-term outcome of patients who underwent posterior interosseous nerve (PIN) denervation for inflammatory arthritis of the wrist.

METHOD

xForty consecutive wrists (36 patients) treated with PIN denervation were identified (mean follow-up 47 months; mean age 62.6 years, 77.5% female). Pain and function scores were objectively measured using the patient-rated wrist-evaluation (PRWE) questionnaires. Data was compared for pre-operation and post-operation (early and long term). The Student's t test was used to compare differences between groups for continuous data, whilst the sign test was utilised for pairwise comparisons. The p value was set at 0.05 for all comparisons.

RESULTS

Three patients died during the course of this study from causes unrelated to wrist surgery, resulting in 93% follow-up. PRWE questionnaires demonstrated a significant improvement following PIN denervation (median pain pre-op 42 vs post-op 16 (p < 0.001); median function pre-op 82 vs post-op 41 (p < 0.001), respectively). There were no differences identified between early and long-term post-operative scores. Four cases (10%) had persistent, ulnar-based pain and required secondary salvage wrist arthrodesis. However, 95% of patients remained "very satisfied" or "satisfied" after surgery.

CONCLUSIONS

This study highlights the effectiveness of PIN denervation as a simple alternative to wrist arthrodesis due to long-term improvement in pain and preservation of function. We recommend this procedure in the presence of a positive diagnostic PIN infiltration test to avoid wrist arthrodesis for as long as possible. In patients with predominantly ulnar-based wrist pain, the outcome is less predictable and this subgroup of patients should be counselled about the possibility of subsequent salvage wrist fusion. Key Points • One of the largest study cohorts which report on the outcome of the wrist PIN denervation procedure with over 2-year follow-up • Clinical outcomes of success are enhanced with the use of validated, objective patient-reported outcome measures relating to overall satisfaction, pain relief and function. • Long-term outcomes are compared to pre-operative and immediate post-operative outcome scores, demonstrating the benefits of PIN denervation and the longevity it provides.

High radial nerve palsy

High radial palsy is primarily associated with humeral shaft fractures, whether primary due to the initial trauma, or secondary to their treatment. The majority will spontaneously recover, therefore early surgical exploration is mainly indicated for open fractures or if ultrasonography shows severe nerve damage. Initial signs of nerve recovery may appear between 2 weeks and 6 months. Otherwise, the decision to explore the nerve is based on the patient's age, clinical examination and electroneuromyography, as well as ultrasonography findings. If recovery does not occur, an autograft is indicated only in younger patients, before 6 months, if local conditions are suitable. Otherwise, nerve transfers performed by an experienced team give satisfactory results and can be offered up to 10 months post-injury. Tendon transfers are the gold standard treatment and the only option available beyond 10 to 12 months. The results are reliable and fast.

Atypical sensory processing pattern following median or ulnar nerve injury - a case-control study

BACKGROUND

Due to brain plasticity a transection of a median or ulnar nerve results in profound changes in the somatosensory areas in the brain. The permanent sensory deprivation after a peripheral nerve injury might influence the interaction between all senses. The aim of the study was to investigate if a median and/or ulnar nerve injury gives rise to a changed sensory processing pattern. In addition we examined if age at injury, injured nerve or time since injury influence the sensory processing pattern.

METHODS

Fifty patients (40 men and 10 women, median age 43) operated due to a median and/or ulnar nerve injury were included. The patients completed the Adolescent/Adult Sensory Profile questionnaire, which includes a comprehensive characterization on how sensory information is processed and how an individual responds to multiple sensory modalities. AASP categorizes the results into four possible Quadrants of behavioral profiles (Q1-low registration, Q2-sensory seeking, Q3-sensory sensitivity and Q4-sensory avoiding). The results were compared to 209 healthy age and gender matched controls. Anova Matched Design was used for evaluation of differences between the patient group and the control group. Atypical sensory processing behavior was determined in relation to the normative distribution of the control group.

RESULTS

Significant difference was seen in Q1, low registration. 40% in the patient group scored atypically in this Quadrant compared to 16% of the controls. No correlation between atypical sensory processing pattern and age or time since injury was seen.

CONCLUSION

A peripheral nerve injury entails altered sensory processing pattern with increased proportion of patients with low registration to sensory stimulus overall. Our results can guide us into more client centered rehabilitation strategies.