Analysis of upper and lower extremity peripheral nerve injuries in a population of patients with multiple injuries

Laser phototherapy (780 nm), a new modality in treatment of long-term incomplete peripheral nerve injury: a randomized double-blind placebo-controlled study

OBJECTIVE

The authors conducted this pilot study to prospectively investigate the effectiveness of low-power laser irradiation (780 nm) in the treatment of patients suffering from incomplete peripheral nerve and brachial plexus injuries for 6 months up to several years.

BACKGROUND DATA

Injury of a major nerve trunk frequently results in considerable disability associated with loss of sensory and motor functions. Spontaneous recovery of long-term severe incomplete peripheral nerve injury is often unsatisfactory.

METHODS

A randomized, double-blind, placebo-controlled trial was performed on 18 patients who were randomly assigned placebo (non-active light: diffused LED lamp) or low-power laser irradiation (wavelength, 780 nm; power, 250 mW). Twenty-one consecutive daily sessions of laser or placebo irradiation were applied transcutaneously for 3 h to the injured peripheral nerve (energy density, 450 J/mm(2)) and for 2 h to the corresponding segments of the spinal cord (energy density, 300 J/mm(2)). Clinical and electrophysiological assessments were done at baseline, at the end of the 21 days of treatment, and 3 and 6 months thereafter.

RESULTS

The laser-irradiated and placebo groups were in clinically similar conditions at baseline. The analysis of motor function during the 6-month follow-up period compared to baseline showed statistically significant improvement (p = 0.0001) in the laser-treated group compared to the placebo group. No statistically significant difference was found in sensory function. Electrophysiological analysis also showed statistically significant improvement in recruitment of voluntary muscle activity in the laser-irradiated group (p = 0.006), compared to the placebo group.

CONCLUSION

This pilot study suggests that in patients with long-term peripheral nerve injury noninvasive 780-nm laser phototherapy can progressively improve nerve function, which leads to significant functional recovery.

Variations in glial cell line-derived neurotrophic factor release from biodegradable nerve conduits modify the rate of functional motor recovery after rat primary nerve repairs

Accelerating axonal regeneration to shorten the delay of reinnervation and improve functional recovery after a peripheral nerve lesion is a clinical demand and an experimental challenge. We developed a resorbable nerve conduit (NC) for controlled release of glial cell line-derived neurotrophic factor (GDNF) with the aim of assessing motor functional recovery according to the release kinetics of this factor in a short gap model. Different types of resorbable NCs were manufactured from a collagen tube and multiple coating layers of poly(lactide-coglycolide), varying in poly(lactide-coglycolide) type and coating thickness to afford three distinct release kinetics of the neurotrophic factor. GDNF release was quantified in vitro. End-to-end suture and GDNF-free NC served as controls. Thirty-five Wistar rats underwent surgery. Motor recovery was followed from 1 to 12 weeks after surgery by video gait analysis. Morphometrical data were obtained at mid-tube level and distal to the NC. NCs were completely resorbed within 3 months with minimal inflammation. GDNF induced a threefold overgrowth of fibers at mid-tube level. However, the number of fibers was similar in the distal segment of all groups. The speed of recovery was inversely proportional to the number of fibers at the NC level but the level of recovery was similar for all groups at 3 months. The resorbable conduits proved their ability to modulate axonal regrowth through controlled release of GDNF. In relation to the dose delivered, GDNF strikingly multiplied the number of myelinated fibers within the NC but this increase was not positively correlated with the return of motor function in this model.

Clinical and user-friendly classification of traumatic digital nerve injuries of hand

INTRODUCTION

Surgical findings of traumatic neurapraxia and neurotmesis in digital nerve injuries of hand have significantly different prognosis and surgeons managing such injuries must be able to provide the expected incidence of these injuries along with decision on surgical exploration. There is a paucity of data in the literature defining the incidence of traumatic neurapraxia and neurotemesis in lacerated hand injuries with clinical features of digital nerve injury.

MATERIALS AND METHODS

We carried out a study in an urban practice to understand this problem on 81 consecutive patients with 82 digital nerve injuries over 1.5 years. Seventy-two percent of the injuries were caused mainly in the domestic accidents by glass and knife. All patients had clinical features of digital nerve injury.

RESULTS

Operative findings revealed nerve damage in 76 patients (confidence interval at 95% = 91-97). Seventy-one had severed nerves and underwent repair (CI at 95% = 80-95). There were 7% patients with operative findings of normal looking nerves and 6% of bruised but intact nerves. All of these 13% patients who did not require surgical repair were grouped as traumatic neurapraxia and showed complete clinical recovery.

CONCLUSION

Traumatic neurapraxia in digital nerve injuries of the hand are not uncommon, as previously thought, following lacerated injuries to hand and have favourable prognosis. This information is important for clinicians in getting more informed consent and patient education. The classification of digital nerve injuries into traumatic neurapraxia and neurotemesis appears logical for its practical application in routine clinical practice.

A novel method for establishing daily in vivo concentration gradients of soluble nerve growth factor (NGF)

Despite the capacity for spontaneous axonal regeneration, recovery following injuries to the peripheral nervous system (PNS) following transection are often incomplete and limited to short distances. Nerve growth factor (NGF) has been previously shown to support neuron survival, and direct growth of both developing and regenerating nerve fibers along a concentration gradient, based largely on in vitro studies. Here, we present a novel in vivo model of administering daily concentration gradients of NGF by directly manipulating the placement of the catheter-nerve conduit junction. Our results show that a dose of 800 pg NGF can be reliably used to establish a chemotactic concentration gradient over both a transient time period, and chronically through repeated daily administrations of the drug. Results from these studies may lead to a better mechanistic understanding of how concentration gradients of soluble NGF influence in vivo peripheral nerve regeneration.

Approaches to neural tissue engineering using scaffolds for drug delivery

This review seeks to give an overview of the current approaches to drug delivery from scaffolds for neural tissue engineering applications. The challenges presented by attempting to replicate the three types of nervous tissue (brain, spinal cord, and peripheral nerve) are summarized. Potential scaffold materials (both synthetic and natural) and target drugs are discussed with the benefits and drawbacks given. Finally, common methods of drug delivery, including degradable/diffusion-based delivery systems, affinity-based delivery systems, immobilized drug delivery systems, and electrically controlled drug delivery systems, are examined and critiqued. Based on the current body of work, suggestions for future directions of research in the field of neural tissue engineering are presented.

Importance of Electromyography and the Electrophysiological Severity Scale in Forensic Reports

Forensic reports on traumatic peripheral nerve injuries include dysfunction degrees of extremities, which are arranged according to the Turkish Penalty Code. The aim of this study is to discuss the role and importance of electromyography while preparing forensic reports in the cases of traumatic peripheral nerve injuries and the usefulness of scoring systems. A modified global scale, recommended by Mondelli et al., was used to assess the electrophysiological impairment of each peripheral nerve. Forensic reports of 106 patients, reported between 2002 and 2004, were evaluated. Thirty-four percent of the cases were reported as "total loss of function," 41.5% were reported as "functional disability," and there were no dysfunctions in the other cases in forensic reports that were prepared based on Council of Social Insurance Regulations of Health Processes and Guide prepared by the Council of Forensic Medicine and profession associations of forensic medicine. When we rearranged these forensic reports based on the electrophysiological severity scale (ESS), it was clearly found that all of the score 2 cases and 86.7% of the score 3 cases corresponded to "functional disability" and 91.4% of the score 4 cases correspond to "total loss of function." We found a significant correlation between the ESS and functional evaluation in peripheral nerve injury cases. Evaluation of functional disabilities in peripheral nerve injuries with the ESS represents a standardized and objective method used for forensic reports.

The CatWalk gait analysis in assessment of both dynamic and static gait changes after adult rat sciatic nerve resection

Functional repair of neurotmesis has been proven most challenging in regenerative medicine. Progress in this field has shown that functional repair not only requires axon regeneration, but also selectivity in target reinnervation. Although selectivity in target reinnervation still involves relatively unexplored avenues, evidence-based medicine, in the end, requires behavioral proof of repair. Therefore, there is a need for tests assessing behavioral deficits after neurotmesis. To date, behavioral tests for detecting both dynamic and static parameters are limited. The CatWalk gait analysis has been shown to detect a multitude of speed-controlled dynamic and static gait deficits after experimental spinal cord injury. Therefore, we here evaluated its use in detecting both dynamic and static gait deficits after neurotmesis. After rat sciatic nerve resection CatWalk testing was performed for 8 weeks. A large amount of dynamic and static gait parameters were detected to be immediately and severely affected in the ipsilateral paw, sometimes reaching levels of only 15% of those of the unaffected paw. We conclude that the CatWalk objectively detects dynamic and static gait impairments after sciatic nerve resection and future experiments are now required to prove which of these parameters are of particular interest to detect functional repair.

Lack of topographic specificity in nerve fiber regeneration of rat forelimb mixed nerves

Multiple nerve repair by means of a Y-shaped nerve guide represents a good model for studying the specificity of peripheral nerve fiber regeneration. Here we have used it for investigating the specificity of axonal regeneration in mixed nerves of the rat forelimb model. The left median and ulnar nerves, in adult female rats, were transected and repaired with a 14-mm Y-shaped conduit. The proximal end of the Y-shaped conduit was sutured to the proximal stump of either the median nerve or the ulnar nerve. Ten months after surgery, rats were tested for functional recovery of each median and ulnar nerve. Quantitative morphology of regenerated myelinated nerve fibers was then carried out by the two-dimensional disector technique. Results showed that partial recovery of both median and ulnar nerve motor function was regained in all experimental groups. Performance in the grasping test was significantly lower when the ulnar nerve was used as the proximal stump. Ulnar test assessment showed no significant difference between the two Y-shaped repair groups. The number of regenerated nerve fibers was significantly higher in the median nerve irrespectively of the donor nerve, maintaining the same proportion of myelinated fibers between the two nerves (about 60% median and 40% ulnar). On the other hand, nerve fiber size and myelin thickness were significantly larger in both distal nerves when the median nerve was used as the proximal donor nerve stump. G-ratio and myelin thickness/axon diameter ratio returned to normal values in all experimental groups. These results demonstrate that combined Y-shaped-tubulization repair of median and ulnar nerves permits the functional recovery of both nerves, independently from the proximal donor nerve employed, and that tissue, and not topographic, specificity guides nerve fiber regeneration in major forelimb mixed nerves of rats.

Hand function after nerve repair

Treatment of injuries to major nerve trunks in the hand and upper extremity remains a major and challenging reconstructive problem. Such injuries may cause long-lasting disabilities in terms of lost fine sensory and motor functions. Nowadays there is no surgical repair technique that can ensure recovery of tactile discrimination in the hand of an adult patient following nerve repair while very young individuals usually regain a complete recovery of functional sensibility. Post-traumatic nerve regeneration is a complex biological process where the outcome depends on multiple biological and environmental factors such as survival of nerve cells, axonal regeneration rate, extent of axonal misdirection, type of injury, type of nerve, level of the lesion, age of the patient and compliance to training. A major problem is the cortical functional reorganization of hand representation which occurs as a result of axonal misdirection. Although protective sensibility usually occurs following nerve repair, tactile discriminative functions seldom recover--a direct result of cortical remapping. Sensory re-education programmes are routinely applied to facilitate understanding of the new sensory patterns provided by the hand. New trends in hand rehabilitation focus on modulation of central nervous processes rather than peripheral factors. Principles are being evolved to maintain the cortical hand representation by using the brain capacity for visuo-tactile and audio-tactile interaction for the initial phase following nerve injury and repair (phase 1). After the start of the re-innervation of the hand (phase 2), selective de-afferentation, such as cutaneous anaesthesia of the forearm of the injured hand, allows expansion of the nerve-injured cortical hand representation, thereby enhancing the effects of sensory relearning. Recent data support the view that training protocols specifically addressing the relearning process substantially increase the possibilities for improved functional outcome after nerve repair.

Luminal fillers in nerve conduits for peripheral nerve repair

The use of nerve conduits as an alternative for nerve grafting has a long experimental and clinical history. Luminal fillers, factors introduced into these nerve conduits, were later developed to enhance the nerve regeneration through conduits. Though many luminal fillers have been reported to improve nerve regeneration, their use has not been subjected to systematic review. This review categorizes the types of fillers used, the conduits associated with fillers, and the reported performance of luminal fillers in conduits to present a preference list for the most effective fillers to use over specific distances of nerve defect.

Prognostic values of electrodiagnostic studies in traumatic radial neuropathy

It is important to have strong predictors of outcome in traumatic neuropathies so that appropriate management can be instituted early. Our objective in this study was to evaluate the prognostic value of electrodiagnostic studies in traumatic radial neuropathy. In this retrospective study, 33 of 67 subjects with traumatic radial neuropathy met the inclusion criteria. Good outcome was defined as grade 3 or higher strength on the Medical Research Council scale in wrist extensors. Compound muscle action potential (CMAP) responses from extensor indicis proprius (EIP) predicted prognosis: 92% of subjects with a recordable CMAP had a good outcome; and 65% of those with an absent response had a good outcome. Recruitment in brachioradialis was also predictive: 92% of those with full, central, or reduced recruitment had a good outcome; 67% of those with discrete recruitment had a good outcome; and only 33% of those with absent recruitment had a good outcome. Studies performed more than 3 months after injury produced more prognostic certainty than those performed earlier. We conclude that electrodiagnostic studies produce useful prognostic information in traumatic radial neuropathy. It is noteworthy, however, that 65% of subjects with an absent radial CMAP (suggesting complete or nearly complete axon loss) still have a good outcome.

Diagnostic ultrasound for nerve transection

The current approach for localizing and assessing the severity of traumatic peripheral nerve injuries involves clinical evaluation and electrodiagnostic studies. However, the ability of this approach to determine the extent of nerve damage within the first 6 weeks after trauma is limited. This is problematic because outcome is improved with early surgical intervention after complete nerve transection. This led us to explore alternative techniques, such as imaging, for assessing peripheral nerve injuries. Twelve fresh cadavers were obtained and after inspection 20 arms were deemed suitable for inclusion in the study. Random sites were transected in median, ulnar, and radial nerves, and sham skin incisions were performed throughout the arm. These nerves were then systematically scanned by an ultrasonographer blinded to the nerve transection sites, who made a final decision as to whether the nerve was transected. High-resolution ultrasound was able to identify transected nerves in the upper extremity with 89% sensitivity and 95% specificity in fresh cadavers. This proof-of-concept study shows that ultrasound can accurately identify nerve transection, which should lead to further ultrasound studies in patients with traumatic peripheral nerve injuries.

Mechanisms of Disease: what factors limit the success of peripheral nerve regeneration in humans?

Functional recovery after repair of peripheral nerve injury in humans is often suboptimal. Over the past quarter of a century, there have been significant advances in human nerve repair, but most of the developments have been in the optimization of surgical techniques. Despite extensive research, there are no current therapies directed at the molecular mechanisms of nerve regeneration. Multiple interventions have been shown to improve nerve regeneration in small animal models, but have not yet translated into clinical therapies for human nerve injuries. In many rodent models, regeneration occurs over relatively short distances, so the duration of denervation is short. By contrast, in humans, nerves often have to regrow over long distances, and the distal portion of the nerve progressively loses its ability to support regeneration during this process. This can be largely attributed to atrophy of Schwann cells and loss of a Schwann cell basal lamina tube, which results in an extracellular environment that is inhibitory to nerve regeneration. To develop successful molecular therapies for nerve regeneration, we need to generate animal models that can be used to address the following issues: improving the intrinsic ability of neurons to regenerate to increase the speed of axonal outgrowth; preventing loss of basal lamina and chronic denervation changes in the denervated Schwann cells; and overcoming inhibitory cues in the extracellular matrix.

Difference in Recovery Potential of Peripheral Nerves after Graft Repairs

OBJECTIVE:

To our knowledge, few studies have been published regarding differences in nerve recovery potentials. In this study, sensory and motor recovery potentials were compared between different nerves.

METHODS:

A prospective study of a homogenous group of 393 graft repairs of the median, ulnar, radial, tibial, peroneal, femoral, and musculocutaneous nerves, with the scoring of motor and sensory recoveries. Sensory and motor recovery potentials, defined on the basis of average scores and rates of useful recovery, were compared between the different nerves, and separately for high-, intermediate-, and low-level repairs.

RESULTS:

Sensory recovery potential was similar for all nerves tested (P > 0.05), but motor recovery potential differed significantly. After high-level repairs, motor recovery potential was significantly better for the radial and tibial nerves (useful recovery in 66.7 and 54.5% of patients, respectively), than for the ulnar and peroneal nerves (useful recovery in 15.4 and 13.8% of patients, respectively; P < 0.05). After intermediate-level repairs, motor recovery potential was better for the musculocutaneous, radial, and femoral nerves (useful recovery in 100, 98.3, and 87.5% of repairs, respectively), than for the tibial, median and ulnar nerves (useful recovery in 63.9, 52, and 43.6% of repairs, respectively; P < 0.05). In addition, motor recovery potential was significantly the worst with peroneal nerve repairs (useful recovery in 15.2% of patients; P < 0.05). After low-level repairs, motor recovery potential was similar for all nerves (useful recovery in the range of 88.9–100% of patients and in 56.3% of peroneal nerve repairs).

CONCLUSION:

Sensory recovery potential is similar for the median, ulnar, and tibial nerves. The expression of motor recovery potential depends on the repair level. With low- and high-level repairs, it does not stand out in an obvious way, but it is fully expressed with intermediate-level repairs, classifying nerves into three categories with excellent, moderate, and poor recovery potential.

Photoengineering of neural tissue repair processes in peripheral nerves and the spinal cord: research development with clinical applications

The purpose of the present paper is to provide our data on the effects of phototherapy on peripheral nerve recovery. The aim is to call attention to an issue that still requires much research to elucidate the biological mechanisms through which phototherapy exerts its effects on nerve tissue, and to provide clinicians with the basis for planning clinical trials on the use of phototherapy for enhancing post-traumatic nerve regeneration.

Nerve palsies related to pediatric upper extremity fractures

In every child who has a fracture, neurologic examination is essential at initial assessment so that early diagnosis of nerve injury can be made. Electrodiagnostic studies may be helpful in diagnosis when the examination is equivocal and in follow-up to look for signs of recovery. In a patient who has neurologic deficits associated with a fracture, nerve exploration should be considered for open fractures, fractures that require open reduction, and palsies that develop after fracture reduction. For closed fractures associated with nerve palsy at the time of initial injury, observation and serial examination after reduction is recommended. If there is no return of nerve function on examination or electrodiagnostic testing by 4 months, operative exploration is indicated.

Closed fractures complicated by peripheral nerve injury

Closed fractures may be complicated by associated peripheral nerve injury. However, because clinical information is limited, determining the best course of treatment is difficult. Most patients with closed fractures have a local nerve injury without nerve division; their prognosis for recovery is favorable. In the acute setting, immediate surgery is usually unwarranted because of the difficulty in accurately defining the severity and extent of nerve injury. When débridement of an open fracture or repair is not required, peripheral nerve injuries are best observed and the extremity treated with splinting and exercise to prevent loss of joint motion. Patients who fail to demonstrate signs of recovery at 6 months, either clinically or with electrodiagnostic testing, should undergo exploration to maximize the likelihood for return of function. When, during exploration, the nerve is in continuity, intraoperative measurement of nerve action potentials should be done. Measuring nerve action potentials will determine whether nerve grafting, local neurolysis, or excision of the injured segment, accompanied by primary repair, is the most appropriate treatment.

Peripheral nerve injuries: A retrospective survey of 456 cases

This 16-year retrospective study reports the data on 456 consecutive patients with 557 peripheral nerve injuries (PNIs) between 1989 and 2004. Most patients were men (74%) and the mean age was 32.4 years. In 83% of cases the PNIs were isolated; combined lesions most commonly involved the ulnar and median nerves. Upper-limb PNIs occurred in 73.5% of cases; the ulnar nerve was most often injured, either singly or in combination. Vehicle accidents affecting the brachial plexus or radial, sciatic, facial, and peroneal nerves were the most common cause of injury. Penetrating trauma commonly affected the ulnar and median nerves; falls and gunshot wounds frequently affected the ulnar, radial, and median nerves; and sports injuries, particularly soccer, affected mainly the peroneal and tibial nerves. More than half of the brachial plexus lesions after vehicular accidents were from motorcycle crashes.

Mononeuropathies of the radial nerve: clinical and neurographic findings in 91 consecutive cases

Retrospective features of 91 consecutive cases (68 men, 23 women; mean age 44.4 years) of radial mononeuropathy diagnosed over the last 8 years in two electromyography (EMG) services are reported to define the clinical and electrophysiological findings of radial neuropathies in relation to traumatic and non-traumatic causes and site of injury. The occurrence of radial neuropathy was 0.65 x 100 first electromyographic examinations. The most frequent site of damage was the main trunk at the spiral groove of the humerus (36%); the most frequent cause was nerve trauma (70%) due to fracture (36%). In neuropathies of the main trunk and posterior interosseous (PI) nerve, "complete nerve injury" was observed in 36% of cases, conduction motor block in 33% and motor conduction velocity slowing in 46%. At least one of these findings was present in 51%, whereas motor neurography was normal in 13% of cases. Sensory action potential (SAP) anomalies were observed in 51% of cases. In neuropathy of the superficial radial nerve, no SAP was detected in 30% of cases; in all others except one, SAP was reduced in amplitude. Non-traumatic neuropathies showed severer conduction block and less severe anomalies of SAP than traumatic neuropathies. No differences were found between men and women. EMG is essential for confirming the site of injury and neurographic study may be helpful for diagnosis, providing information about lesion type and severity.

End-to-side nerve grafting of the tibial nerve to bridge a neuroma-in-continuity

Standard treatment for a neuroma-in-continuity with partial retained function is neurolysis with or without grafting. The present study tests the outcome of a novel partial nerve lesion bypassed with an end-to-side bridge graft, intended to increase the number of axons crossing the defect while not disturbing intact axons. An 8-mm portion of tibial nerve was resected in 20 rats. Three weeks later, half had the defect repaired with an end-to-side bridge allograft and perineurial windows; controls had only neurolysis. Recovery was evaluated using walking-track analysis, allodynia testing, muscle weight ratios, and histology at 8 weeks. No significant differences in motor or sensory functional recovery were noted between the two groups. Histology showed good axonal regeneration through the defect in all specimens. The experimental group also had regenerated axons in the bridge graft, but their maturity was less advanced, presumably due to delays in regeneration.

High-resolution magnetic resonance imaging of the human median nerve

OBJECTIVES

It is widely accepted that peripheral nerve repairs performed within 6 weeks of injury have much better outcomes than those performed at later dates. However, there is no diagnostic technique that can determine if a traumatic peripheral nerve injury requires surgical intervention in the early postinjury phase. The objective of this article was to determine whether novel, noninvasive magnetic resonance imaging techniques could demonstrate the microstructure of human peripheral nerves that is necessary for determining prognosis and determining if surgery is indicated following traumatic injury.

METHODS

Ex vivo magnetic resonance imaging protocols were developed on a 9.4-T research scanner using spin-echo proton density and gradient-echo imaging sequences and a specially designed, inductively coupled radio frequency coil. These imaging protocols were applied to in situ imaging of the human median nerve in 4 fresh-frozen cadaver arms.

RESULTS

Noninvasive high-resolution images of the human median nerve were obtained. Structures in the nerve that were observed included fascicles, interfascicular epineurium, perineurium, and intrafascicular septations.

CONCLUSION

Application of these imaging techniques to clinical scanners could provide physicians with a tool that is capable of grading the severity of nerve injuries and providing indications for surgery in the early postinjury phase.

Management and outcomes in 318 operative common peroneal nerve lesions at the Louisiana State University Health Sciences Center

OBJECTIVE

This study analyzes 318 operative knee-level common peroneal nerve lesions managed at the Louisiana State University Health Sciences Center between 1967 and 1999.

METHODS

Each patient was retrospectively evaluated for injury mechanism, preoperative neurological status, electrophysiological studies, lesion type, and operative technique, i.e., neurolysis, suture, or graft repair. All lesions in continuity had intraoperative nerve action potential recordings.

RESULTS

There were 141 stretch/contusions without fracture/dislocations (44%), 39 lacerations (12%), 40 tumors (13%), 30 entrapments (9%), 22 stretch/contusions with fracture/dislocations (7%), 21 compressions (7%), 13 iatrogenic injuries (4%), and 12 gunshot wounds (4%). After neurolysis, 107 (88%) of 121 knee-level common peroneal nerve lesions with recordable intraoperative nerve action potentials recovered useful function. Nineteen patients underwent end-to-end suture repair, and 16 (84%) of these achieved good recovery by 24 months. Graft repair was performed in 138 peroneal injuries. Thirty-six patients (26%) had grafts less than 6 cm long, of which 27 (75%) achieved Grade 3 or greater peroneal function. Twenty-four (38%) of 64 patients with 6- to 12-cm grafts, and only 6 (16%) of 38 patients with 13- to 24-cm grafts, attained good peroneal function. Longer grafts correlated with more severe injuries and thus poorer outcomes. Thirty-two (80%) of 40 tumors were resected with preservation of preoperative clinical function.

CONCLUSION

Surgical exploration and repair of peroneal nerve lesions achieved good results with timely operations and thorough intraoperative evaluations. Useful function was achieved in 27 (75%) of 36 patients with grafts less than 6 cm in length and in only 88 (44%) of 202 patients with grafts greater than 6 cm in length.

Peripheral nerve regeneration through guidance tubes

Biological nerve grafts have been extensively utilized in the past to repair peripheral nerve injuries. More recently, the use of synthetic guidance tubes in repairing these injuries has gained in popularity. This review focuses on artificial conduits, nerve regeneration through them, and an account of various synthetic materials that comprise these tubes in experimental animal and clinical trials. It also lists and describes several biomaterial considerations one should regard when designing, developing, and manufacturing potential guidance channel candidates. In the future, it it likely that the most successful synthetic nerve conduit will be one that has been fabricated with some of these strategies in mind.

Predictors for return to work in patients with median and ulnar nerve injuries

PURPOSE

One of the consequences of median and ulnar nerve trauma is delayed return to work. The aim of this study was to determine return to work (RTW) and risk factors for delayed RTW in addition to time off work (TOW). Differences among median, ulnar, and combined median-ulnar nerve injuries were examined.

METHOD

In this study 96 patients who were employed at the time of injury and who had undergone surgery for median, ulnar, or combined nerve injuries between 1990 and 1998 were evaluated. The response rate was 84% (n = 81).

RESULTS

Within 1 year after injury, 59% (n = 48) returned to work. Mean TOW was 31.3 weeks. Return to work after combined nerve injuries was 24% versus after isolated median (80%) and ulnar (59%) nerve injuries. Level of education, type of job, and compliance to hand therapy were predictors for RTW. Furthermore, grip strength loss, tip pinch strength loss, and sensory recovery differed strongly between the RTW and no-RTW population.

CONCLUSIONS

The predictors found in this study increase our understanding of delayed RTW after median and ulnar nerve injury and may be used to optimize postinjury rehabilitation.

Early psychological stress after forearm nerve injuries: a predictor for long-term functional outcome and return to productivity

Forearm and wrist injuries can result in a nonfunctional hand caused by loss of motor and sensory functions. Psychological stress is known to accompany traumatic hand injuries and may therefore affect functional outcome. The authors conducted a retrospective study of 107 patients diagnosed with a median, ulnar, or combined median-ulnar nerve injury (79% response rate) who completed a questionnaire package consisting of the Impact of Event Scale (IES); Disabilities of Arm, Shoulder, and Hand; and a questionnaire concerning return to work and time off work. In an outpatient setting, motor and sensory recovery were examined. Ninety-four percent of those studied experienced early psychological stress. Thirty-six percent of patients reported sufficient symptoms 1 month postoperatively to be classified as in need for psychological treatment (IES score > 30 points). Combined median-ulnar nerve injuries (mean, 35.0 +/- 20.3 points [standard deviation]) were accompanied by a higher psychological stress compared with single nerve injuries (median injuries: mean, 24.2 +/- 20.6 points; ulnar injuries: mean, 22.6 +/- 19.5 points; p = 0.049 and p = 0.021 respectively). Multiple linear regression adjusting for age, gender, and severity of the trauma revealed an association between the IES score and the functional symptom score (beta = 0.51; 95% confidence interval [CI], 0.35-0.65), mean time off work (beta = 0.44; 95% CI, 0.25-0.75), and motor recovery (grip: beta = 0.37; 95% CI, 0.09-0.65; tip-pinch: beta = 0.46; 95% CI, 0.13-0.80). Patients with higher scores on the IES were found to be at increased risk for incapacity for work (odds ratio, 3.32; 95% CI, 1.60-6.91). Higher education was found to be a protecting variable for posttraumatic psychopathology (beta = -0.23; 95% CI, -6.05--0.246). This study demonstrated a high level of early posttraumatic psychological stress after forearm and wrist nerve injuries. These data provide evidence that functional outcome and work resumption are influenced negatively by early psychological stress, independent from severity of the somatic trauma. This indicates that outcome after upper extremity nerve injuries may be influenced positively by psychological intervention.

Radial nerve injuries from gunshot wounds and other trauma: comparison of electrodiagnostic findings

OBJECTIVE

To identify the difference and similarity of radial nerve injury in gunshot wounds compared to blunt trauma with regard to level of injury, completeness of injury, and other associated nerve injury.

DESIGN

This study was a retrospective review of electrophysiologic data performed in an electromyographic laboratory of a county hospital. A total of 67 consecutive patients had gunshot wounds or other trauma to the radial nerve during a 7-yr period (1992-1998). Forty patients met the criteria for this study. The radial nerve injury was categorized according to the level of involvement and completeness of injury. The relationship between the etiology, level of injury, completeness of injury, and other associated nerve injury was analyzed via Fisher's exact test.

RESULT

There was no difference in the level of radial nerve injury, completeness of nerve injury, and associated nerve involvement between gunshot wound cases and blunt trauma cases.

CONCLUSION

In contrast to the upper and lower extremity traumatic plexopathy in which differences were seen, our study showed that gunshot wound-induced radial nerve injury is similar to injury induced by other trauma in the factors measured.

Median, ulnar, and combined median-ulnar nerve injuries: functional outcome and return to productivity

BACKGROUND

Forearm and wrist injuries are a common cause of morbidity and are often associated with suboptimal recovery of hand function. This study describes and compares outcome after median, ulnar, or combined median-ulnar nerve injuries.

METHODS

Three hundred thirteen wrist and forearm nerve injuries operated on between 1980 and 1997 in a large university hospital were reviewed in relation to complications, return to work, and sensor and motor recovery. Of these 313 patients, 220 (age range, 5-73 years) met the inclusion criteria.

RESULTS

Motor recovery, progress of sensory reinnervation, and number of severed structures were related to the type of injury (p < 0.05). Multiple linear regression analysis revealed a relation between the appearance of sensory reinnervation and motor recovery (beta = 0.02; 95% confidence interval, 0.01-0.04; p = 0.01). A probability of 24% of work loss, after a mean follow-up of 17.7 months, was found. Poor sensory and motor recovery were associated with work disability (odds ratio [OR], 2.9; p = 0.002; and OR, 2.9; p = 0.007, respectively). No relationship was found between type of injury and return to work (p = 0.47). Level of injury (OR, 2.6; p = 0.01), type of work (OR, 3.1; p = 0.002), number of complications (p < 0.001), and hand-therapy (OR, 0.24; p = 0.001) were found to influence return to work.

CONCLUSION

It may be concluded that peripheral nerve injuries at the forearm level can result in substantial functional loss and have major social consequences. This study identified factors influencing return to work that can be used to optimize postoperative treatment strategy.

Traumatic injury to peripheral nerves

This article reviews the epidemiology and classification of traumatic peripheral nerve injuries, the effects of these injuries on nerve and muscle, and how electrodiagnosis is used to help classify the injury. Mechanisms of recovery are also reviewed. Motor and sensory nerve conduction studies, needle electromyography, and other electrophysiological methods are particularly useful for localizing peripheral nerve injuries, detecting and quantifying the degree of axon loss, and contributing toward treatment decisions as well as prognostication.

Peripheral nerve repair and grafting techniques: a review

In this review, various conventional nerve repair techniques including direct epineurial repair, grouped fascicular repair, fascicular repair, and nerve grafting are described. The indications for use, as well as the relative advantage and disadvantage, of each technique are discussed. The experimental and clinical evidence from a review of the pertinent literature does not demonstrate a significant difference in outcome of one method over the others. Surgical decisions should be made by a thorough evaluation of all aspects of the nerve injury and surgical methods. All nerve injuries cannot be repaired using only one type of nerve repair method. The surgeon should be familiar with all the techniques described and be prepared to use them under appropriate circumstances.