Results of clinical assessment after primary digital nerve repair

Revealing digital nerve lesions-A comprehensive analysis of 2084 cases of a specialized center

BACKGROUND

Finger nerve injuries have a significant impact on hand function and can result in reduced sensation, pain and impaired coordination. The socioeconomic implications of these injuries include decreased workplace productivity, reduced earning potential, and financial burdens associated with long-term medical treatment and rehabilitation. However, there is a lack of comprehensive literature regarding the incidence, mechanisms, and associated injuries of finger nerve lesions.

METHODS

A retrospective analysis was conducted on patients treated at our institution from January 2012 to July 2020. Cases of peripheral finger nerve lesions were identified using the digital hospital information system and ICD-10 Classification. Exclusion criteria included injuries to the median nerve at the carpal tunnel level or superficial branch of the radial nerve. Data were collected using a pseudonymized approach, and statistical analyses were performed using SPSS Statistics (Version 27).

RESULTS

A total of 2089 finger nerve lesions were analyzed, with a majority of cases occurring in men. Most injuries97.4 % were caused by trauma, predominantly cut/tear injuries. Isolated finger nerve injuries were more common than multiple nerve injuries, with the index finger being the most frequently affected. Concomitant tendon and vascular injuries were observed in a significant proportion51.7 % of cases. Surgical management included direct nerve coaptation, interposition grafting and neurolysis.

DISCUSSION

Finger nerve injuries are the most prevalent type of nerve injury, often resulting from small lacerations. These injuries have substantial societal costs and can lead to prolonged sick leave. Understanding the epidemiology and etiology of finger nerve injuries is crucial for implementing effective preventive measures. Accompanying tendon injuries and the anatomical location of the nerve lesions can impact sensory recovery and treatment outcomes. Proper management of peripheral finger nerve lesions is essential for optimizing functional outcomes and minimizing the impact on daily activities. Treatment options should be tailored to the severity and underlying cause of the nerve injury.

Digital nerve injury: to repair or not?

BACKGROUND

There are very few studies comparing patients with and without repair after digital nerve injury. It is still controversial whether digital nerve repair is necessary.

AIMS

The aim of this study was to evaluate the long-term clinical outcomes of patients with unilateral isolated digital nerve injury who underwent surgical repair and those who did not.

METHODS

Seventy-four patients with unilateral digital nerve injury were included in the study. Of these, the patients who underwent surgical repair were determined as group A (n = 42), the patients without repair as group B (n = 32), and the groups were divided into subgroups according to injury levels. Results were evaluated with a minimum follow-up of 24 months.

RESULTS

When the S2PD results were evaluated overall, it was found that those who had digital nerve repair (group A) had significantly better outcomes compared to those without repair (group B) (p = 0.012). When the subgroups were evaluated according to the injury localization, no significant difference was observed at the distal levels, while it was observed that the patients who underwent repair in the proximal levels showed significantly better results (p = 0.003, p = 0.012).

CONCLUSION

In this study, it was seen that there was no difference between the results of repair and non-repair of unilateral nerve injuries distal to the middle level of the middle phalanx, but repair is required in injuries proximal to this level.

Treatment options for digital nerve injury: a systematic review and meta-analysis

BACKGROUND

Surgical treatment of finger nerve injury is common for hand trauma. However, there are various surgical options with different functional outcomes. The aims of this study are to compare the outcomes of various finger nerve surgeries and to identify factors associated with the postsurgical outcomes via a systematic review and meta-analysis.

METHODS

The literature related to digital nerve repairs were retrieved comprehensively by searching the online databases of PubMed from January 1, 1965, to August 31, 2021. Data extraction, assessment of bias risk and the quality evaluation were then performed. Meta-analysis was performed using the postoperative static 2-point discrimination (S2PD) value, moving 2-point discrimination (M2PD) value, and Semmes-Weinstein monofilament testing (SWMF) good rate, modified Highet classification of nerve recovery good rate. Statistical analysis was performed using the R (V.3.6.3) software. The random effects model was used for the analysis. A systematic review was also performed on the other influencing factors especially the type of injury and postoperative complications of digital nerve repair.

RESULTS

Sixty-six studies with 2446 cases were included in this study. The polyglycolic acid conduit group has the best S2PD value (6.71 mm), while the neurorrhaphy group has the best M2PD value (4.91 mm). End-to-side coaptation has the highest modified Highet's scoring (98%), and autologous nerve graft has the highest SWMF (91%). Age, the size of the gap, and the type of injury were factors that may affect recovery. The type of injury has an impact on the postoperative outcome of neurorrhaphy. Complications reported in the studies were mainly neuroma, cold sensitivity, paresthesia, postoperative infection, and pain.

CONCLUSION

Our study demonstrated that the results of surgical treatment of digital nerve injury are generally satisfactory; however, no nerve repair method has absolute advantages. When choosing a surgical approach to repair finger nerve injury, we must comprehensively consider various factors, especially the gap size of the nerve defect, and postoperative complications. Type of study/level of evidence Therapeutic IV.

Digital Nerve Injury: Assessment and Treatment

Undertreated digital nerve injuries may result in sensory deficits and pain. Early recognition and treatment will optimize outcomes, and providers should maintain a high index of suspicion when assessing patients with open wounds. Acute, sharp lacerations may be amenable to direct repair while avulsion injuries or delayed repairs require adequate resection and bridging with nerve autograft, processed nerve allograft, or conduits. Conduits are most appropriate for gaps less than 15 mm, and processed nerve allografts have demonstrated reliable outcomes across longer gaps.

Rapid and effective fusion repair of severed digital nerves using neurorrhaphy and bioengineered solutions including polyethylene glycol: A case report

Peripheral nerve injuries (PNIs) that consist of simple nerve severance often result in severe motor impairment and permanent loss of function. Such patients face significant costs and pose major burdens to healthcare systems. Currently, the most promising surgical technique to achieve the best clinical outcome after such PNIs is immediate primary coaptation of severed nerve ends by microsutures (neurorrhaphy). However, recovery is often poor and delayed for many months due to Wallerian degeneration (WD) and slow (1-2 mm/day) axonal outgrowths from severed proximal axons that may not properly reinnervate denervated afferent/efferent targets that have atrophied. In contrast, recent pre-clinical studies using polyethylene glycol (PEG) to facilitate primary nerve repair have greatly improved the rate and extent of sensory and motor recovery and prevented much WD and muscle atrophy. That is, PEG-fused axons rapidly establish proximal-distal axoplasmic/axolemmal continuity, which do not undergo WD and maintain the structure and function of neuromuscular junction (NMJ). PEG-fused axons rapidly reinnervate denervated NMJs, thereby preventing muscle atrophy associated with monthslong denervation due to slowly regenerating axonal outgrowths. We now describe PEG-mediated fusion repair of a digital nerve in each of two patients presenting with a digital laceration resulting in total loss of sensation. The first patient's tactile perception improved markedly at 3 days postoperatively (PO). Two-point discrimination improved from greater than 10 mm at initial presentation to 4 mm at 11-week PO, and the Semmes-Weinstein monofilament score improved from greater than 6.65 to 2.83 mm, a near-normal level. The second patient had severe PO edema and scar development requiring a hand compression glove and scar massage, which began improving at 11-week PO. The sensory function then improved for 4 months PO, with both two-point discrimination and Semmes-Weinstein scores approaching near-normal levels at the final follow-up. These case study data are consistent with data from animal models. All these data suggest that PEG-fusion technologies could produce a paradigm shift from the current clinical practice of waiting days to months to repair ablation PNIs with autografts, anucleated nerve allografts, or conduits in which the patient outcome is solely dependent upon axon regeneration over months or years.

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.

Long-term sensibility outcomes of secondary digital nerve reconstruction with sural nerve autografts: a retrospective study

Background

Recovery of sensibility after digital nerve injury is crucial for restoring normal hand function. We evaluated long-term outcomes of digital nerve reconstruction with autografts.

Methods

This retrospective study included patients who underwent secondary reconstruction of digital nerves with nerve autografting. Recovery of sensibility was evaluated based on the following: patient self-assessment, two-point discrimination (2PD), and a total sensation score (sum of proprioception, temperature sensation, and sharp/dull discrimination). Mixed models regression was used to study predictors of sensibility outcomes. The predictors analyzed were age, sex, smoking status, number of fingers involved in a patient (as a measure of injury severity), time to reconstruction, and time to follow-up.

Results

In 61 patients, 174 digital nerves in 126 fingers were reconstructed after an average of 33.1 weeks from injury. The mean follow-up was 6.4 years from reconstruction. The mean graft length was 3.6 cm. Self-rated sensibility in the affected area was very good in 13% of patients, good in 33%, satisfactory in 40%, and poor in 24%. 2PD at 6 mm was present in 17% of patients, at 10 mm in 12%, and at 15 mm in 18% (mean 2PD was 10.8). Proprioception was preserved in 107 (85%) fingers, sensation of temperature was preserved in 99 (75%) of fingers, and sharp/dull discrimination in 88 (70%) fingers. Time from injury to reconstruction was the only significant predictor of the total sensation score.

Conclusion

Our data indicate that earlier reconstruction is associated with a favorable outcome.

Impact of Body Mass Index and Comorbidities on Outcomes in Upper Extremity Nerve Transfers

BACKGROUND

 There is a paucity of research investigating the impact of patient comorbidities, such as obesity and smoking, on nerve transfer outcomes. The objective of this retrospective cohort study was to evaluate the impact of body mass index (BMI) and comorbidities on the clinical outcomes of upper extremity nerve transfers.

METHODS

 A retrospective cohort study was executed. Patients were eligible for inclusion if they had an upper extremity nerve transfer with a minimum of 12-months follow-up. Data was collected regarding demographics, comorbidities, injury etiology, nerve transfer, as well as preoperative and postoperative clinical assessments. The primary outcome measure was strength of the recipient nerve innervated musculature. Statistical analysis used the Mann-Whitney U test, Wilcoxon signed-rank test, and Spearman's rho.

RESULTS

 Thirty-eight patients undergoing 43 nerve transfers were eligible for inclusion. Patients had a mean age of 48.8 years and a mean BMI of 27.4 kg/m² (range:19.7-39.0). Injuries involved the brachial plexus (32%) or its terminal branches (68%) with the most common etiologies including trauma (50%) and compression (26%). Anterior interosseous nerve to ulnar motor nerve (35%) was the most common transfer performed. With a mean follow-up of 20.1 months, increased BMI (p = 0.036) and smoking (p = 0.021) were associated with worse postoperative strength.

CONCLUSION

 This retrospective cohort study demonstrated that increased BMI and smoking may be associated with worse outcomes in upper extremity nerve transfers-review of the literature yields ambiguity in both regards. To facilitate appropriate patient selection and guide expectations regarding prognosis, further experimental and clinical work is warranted.

Surgically Treated Pediatric Hand and Fingers Palmar Wounds Caused by Metal Fences: Analysis Over a 5-Year Period

BACKGROUND

Hand wounds are frequent in children (31% of hand injuries) and one possible mechanism responsible for profound laceration is metal fences while climbing. These injuries usually require a surgical look to explore soft-tissue damages, but the literature is poor regarding surgical findings and outcomes after this kind of traumatism. The aim of the study was therefore to report a consecutive series of hand and finger wounds caused by metal fences in children, focusing on surgical findings and potential complications.

METHODS

All consecutive hand or finger deep wounds caused by metal fences treated between January 2013 and December 2018 were retrospectively reviewed. Inclusion criteria were age below 18 years and a minimum follow-up of 2 years. Complications and surgical revisions were analyzed.

RESULTS

A total of 1265 patients were operated for hand or finger deep wounds during the study period, among which 74 were caused by metal fences. The mean age at surgery was 11.3±0.4 years, and the majority of patients were men (80%). Associated injuries were found in 55.4% of the patients including nerves (n=29) or tendons sections/disinsertion (n=6), and sheath (n=16) and pulleys (n=6) tearing. At a mean follow-up of 2.6±0.2 years, 12% of the patients required revision surgery for an irreducible flexion contracture secondary to a contractile scar and consisted of complete scar excision and zigzag flap. Additional tenoarthrolysis was required during the procedure, for 6 patients because of a persisting flexion contracture after excision.

CONCLUSIONS

Metal fences surgical palmar wounds in children are impressive lesions by their extended skin damages. Serious associated lesions (collateral pedicle or flexor tendons) were found in 1 case of 3. However, these injuries are not benign and should be carefully monitored clinically during the first postoperative month to look for potential contractile scars that can require revision.

LEVEL OF EVIDENCE

Level IV-retrospective cohort study.

A Quantitative Systematic Review of Clinical Outcome Measure Use in Peripheral Nerve Injury of the Upper Limb

BACKGROUND

Peripheral nerve injury (PNI) is common, leading to reduced function, pain, and psychological impact. Treatment has not progressed partly due to inability to compare outcomes between centers managing PNI. Numerous outcome measures exist but there is no consensus on which outcome measures to use nor when.

OBJECTIVE

To perform a systematic review in order to describe and classify outcome measures used in PNI.

METHODS

A search of Ovid Medline, Ovid Embase, Allied and Complementary Medicine Database (AMED), and CENTRAL (Cochrane Clinical Trials) was conducted. Randomized control trials (RCTs), cohort studies, and case-controlled and case series (≥5 participants) published from inception of the database until 2019 investigating adult patients with a traumatic upper limb PNI in which an outcome measurement was utilized were included.

RESULTS

A total of 96 studies were included (15 RCTs, 8 case-control studies, 18 cohort studies, 5 observational studies, and the remainder were case series or retrospective reviews). A total of 56 individual outcome measures were identified, utilized across 28 different countries and 7097 patients. Ten core domains were defined: sensory subjective, sensory objective, motor subjective, motor objective, sensorimotor function, psychology and well-being, disability, quality of life, pain and discomfort, and neurotrophic measures.

CONCLUSION

Lack of consensus on outcome measure use hinders comparison of outcomes between nerve injury centers and the development of novel treatments. Development of a core outcome set will help standardize outcome reporting, improve translation of novel treatments from lab to clinical practice, and ensure future research in PNI is more amenable to systematic review and meta-analysis.

Outcomes of surgical repair of a single digital nerve in adults

Current standard management of a cut digital nerve is end-to-end microsurgical nerve coaptation where possible. A recent systematic review of adult digital nerve injuries that were either repaired or left unrepaired showed that the evidence for good nerve recovery or improved function following nerve repair is poor. In the 30 studies included, only 24% of repaired nerves regained sensory recovery close to or equivalent to estimated pre-injury levels. Neuroma rates were the same in those nerves repaired (4.6%) and those not repaired (5%). Questions under debate include proper assessment methods of outcomes, decision making for repair or no repair to different fingers or the thumb, levels of injury, age, and hand dominance. This review summarizes the major evidence available and debates the surgical dogma that surrounds this injury.

Outcome of surgical repair of adult digital nerve injury: a systematic review

OBJECTIVES

A systematic review to assess the evidence supporting surgical repair of digital nerve injury versus no repair in adults in terms of clinical outcomes.

DESIGN

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review with methodology based on the Cochrane Handbook of Systematic Reviews of Interventions.

DATA SOURCES

Databases included OvidMEDLINE, EMBASE, AMED, clinicaltrials.gov and the Cochrane Database of Systematic Reviews, searched from inception until 10 November 2018.

ELIGIBILITY CRITERIA

Adult digital nerve injury in which either direct repair or no repair was undertaken and an outcome measure was recorded.

DATA EXTRACTION AND SYNTHESIS

Study data extracted included demographics, injury type and extent, timing, treatment details, outcome data and time points, adverse outcomes, hand therapy and return to work. The National Institute of Health quality assessment tool for case series was used to assess risk of bias.

RESULTS

Thirty studies were included. One compared surgical repair with non-repair. All studies were case series of between 15 and 110 nerve injuries, with heterogeneous patient, injury and treatment characteristics. Two studies detailed nerve repair without magnification. Static 2-point discrimination (s2PD) was the most commonly reported outcome measure. Return of protective sensation was achieved in most cases in the nerve repair and no nerve repair groups. Repair resulted in better s2PD than no repair, but <25% repaired nerves achieved normal levels. Adverse outcomes were similar between repair and no repair groups.

CONCLUSIONS

Only level IV evidence is available to support surgical repair of digital nerves in adults. Return of normal sensibility is uncommon and almost all unrepaired nerves regained protective sensation by 6 months and all patients declined further surgery. There was no difference in adverse outcomes. There is currently a lack of high-quality evidence to support surgical repair of digital nerve injuries in adults and further research is needed.

PROSPERO REGISTRATION NUMBER

CRD42017065092.

Enhancing the Outcome of Traumatic Sensory Nerve Lesions of the Hand by Additional Use of a Chitosan Nerve Tube in Primary Nerve Repair: A Randomized Controlled Bicentric Trial

BACKGROUND

Peripheral sensory nerve injuries present a significant yet common challenge in acute hand trauma surgery. Standard treatment remains microsurgical end-to-end nerve repair where appropriate. Permanent loss of sensitivity and painful neuroma formation are typical sequelae of unsuccessful surgery. The objective of this study was to evaluate whether the additional use of a chitosan nerve tube in primary nerve repair positively influences sensory recovery.

METHODS

A randomized, controlled, two-center trial with parallel group design and double-blind assessment was conducted to demonstrate the superiority of the additional use of a chitosan nerve tube compared with microsurgical nerve repair alone. Seventy-four participants were enrolled. The primary outcome parameter used was degree of static two-point discrimination at 6 months after surgery. Additional secondary outcome parameters included filament recognition testing (Semmes-Weinstein); pain; neuroma development; and the Disabilities of the Arm, Shoulder and Hand score.

RESULTS

Nerve repair with additional use of chitosan nerve tubes (intervention group) significantly increased both tactile gnosis (expressed by two-point discrimination) and sensitivity (expressed by Semmes-Weinstein testing). The mean two-point discrimination at 6-month follow-up was 8 mm (range, 2 to 20 mm) in the control group and 6.3 mm (range, 1 to 15 mm) in the intervention group, respectively (p = 0.029). Two-point discrimination correlated with the Disabilities of the Arm, Shoulder and Hand score. In the control and intervention groups, respectively, three versus zero neuromas were found.

CONCLUSIONS

Peripheral sensory nerve regeneration can be improved significantly by additional use of a chitosan nerve tube. An improved ability of static two-point discrimination is clinically relevant.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

Peripheral nerve injuries in the pediatric population: a review of the literature. Part I: traumatic nerve injuries

OBJECTIVE

This article reviews the clinical results that can be obtained after repair of a traumatic peripheral nerve injury in the pediatric population.

METHODS

A systematic review of the published literature has been made.

RESULTS

Functional outcome after major nerve injuries is sometimes disappointing in adults. However, children have been reported to experience much better functional results after nerve repair than adults. Moreover, recovery generally is faster in children. The superior capacity of children's central nervous system to adapt to external or internal environmental changes (neural plasticity) and the shorter recovery distance from the axon repair site to the target muscle are claimed to be crucial determinants of their favorable outcomes. Moreover, even in the pediatric population, it has been demonstrated that functional results are better the younger the patient is, including better clinical results in those injured in early childhood (< 6 years old) than in those injured in adolescence. Other favorable prognostic factors include the type of nerve injury (with complete transections doing less well than crush injuries) and the timing of surgery (with better outcomes after early repairs).

CONCLUSIONS

All efforts should be done to repair in a timely and adequate fashion traumatic peripheral nerve injuries in children, as the results are good.

Hypercholesterolemia Is Associated with the Subjective Evaluation of Postoperative Outcomes in Patients with Idiopathic Carpal Tunnel Syndrome Who Undergo Surgery: A Multivariate Analysis

BACKGROUND

Carpal tunnel syndrome is a compression neuropathy of the median nerve at the wrist; its symptoms include neuropathic pain and sensory and motor disturbance distributed by the median nerve. Carpal tunnel syndrome and hypercholesterolemia have similar backgrounds, but the effect of these similarities on postoperative outcomes has not been reported. Using multivariate analysis, the authors analyzed the relationship between prognostic factors, including the presence of hypercholesterolemia, and subjective postoperative outcomes of patients with idiopathic carpal tunnel syndrome.

METHODS

Of 168 hands with carpal tunnel syndrome that were treated surgically, 141 that were followed up and assessed 1 year postoperatively or thereafter were included. The mean postoperative follow-up period was 40.8 months. Surgery was performed through a small palmar skin incision under local anesthesia. The outcomes were postoperative symptoms, including pain and numbness, and overall Kelly assessment.

RESULTS

Preoperative numbness and pain resolved and alleviated in 94 of 141 hands and was diminished in 59 of 64 hands. Univariate analysis showed that postoperative numbness and Kelly assessment were significantly associated with hypercholesterolemia. Multivariate analysis showed that postoperative numbness was significantly associated with smoking and hypercholesterolemia, and Kelly assessment was significantly associated with smoking (adjusted OR, 3.3; 95 percent CI, 1.1 to 10; p = 0.04) and hypercholesterolemia (adjusted OR, 2.9; 95 percent CI, 1.4 to 6.3; p = 0.01).

CONCLUSION

Hypercholesterolemia, usually a systemic condition in sites other than the hand, is associated with the subjective evaluation of postoperative symptoms in patients with idiopathic carpal tunnel syndrome.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Age does not affect the outcome after digital nerve repair in children - A retrospective long term follow up

BACKGROUND

Digital nerve injuries in children are not common, but they are considered to have an excellent prognosis, compared to adults, after nerve injury and repair. In studies including both children and adults age have been found to have an effect on outcome after nerve repair.

METHODS

We investigated in a retrospective follow up study the long-time result after digital nerve injury and repair in children, 1-16 years of age (n = 38), and evaluate if age influences outcome. A group with young children, 1-10 years of age (n = 18), was compared with a group with older children, 11-16 years of age (n = 20). A clinical evaluation to evaluate sensation and grip strength was performed and questionnaires were used [Disability of the Arm, Shoulder and Hand (DASH), Cold Sensitivity Severity Scale (CISS), VAS-function and VAS-cosmetic] in median 40 months (range 12-131 months) after the injury and repair.

RESULTS

All patient regained normal sensation. No correlations between age and monofilaments were found. Twenty children (52%) reported some problems with cold intolerance (i.e. CISS), but no other abnormal disability was found (i.e. DASH, VAS); again with no differences between the two groups.

CONCLUSIONS

Children have an excellent long-term recovery after a digital nerve repair and without any influence of age.

Long-term clinical outcome after epineural coaptation of digital nerves

This study evaluates the long-term clinical outcome and complication rate after digital nerve repair in adults and aims to identify possible prognostic factors of sensory recovery. End-to-end epineural coaptation was performed under magnification. A total of 93 coapted digital nerves were clinically evaluated with a mean follow-up of 3.5 years (range 1-6 years). The mean two-point discrimination was 10.6 mm (versus 4.4 mm for the contralateral side). Cutaneous pressure threshold tested with Semmes-Weinstein monofilaments showed a mean value of 2.7 (versus 2.2 for the contralateral side). Only 2% of our patients developed painful neuromas. None of our patients recovered normal functional sensibility, however, recovery of protective sensation contributed to a high reported level of satisfaction. No correlation was observed between the sensory outcome and age, smoking, mechanism of injury, lesion to or anastomosis of a digital artery, or time of immobilization. The only identified predictor of the result was the surgeon's level of experience. This highlights the importance of adequate training and practice in the surgical repair of smaller peripheral nerves.

LEVEL OF EVIDENCE

IV.

Comparison of digital nerve sensory recovery after repair using loupe or operating microscope magnification

Our purpose was to determine whether there was a significant difference in sensory recovery after digital nerve repair using loupe magnification or an operating microscope. We identified patients aged 21-75 who had primary proper digital nerve repairs at least 24 months before our study. A total of 12 patients with 13 digital nerve injuries repaired with loupe magnification and nine patients with 12 digital nerve injuries repaired using the operating microscope, agreed to return for assessment by a therapist blinded to treatment. We found no significant difference in sensory recovery between the two groups as measured by static two-point discrimination, moving two-point discrimination, and Semmes-Weinstein monofilament. There were also no significant differences in average Disabilities of the Arm Shoulder and Hand or visual analogue pain scores.

LEVEL OF EVIDENCE

IV.

Electrical stimulation enhances sensory recovery: a randomized controlled trial

OBJECTIVE

Brief postsurgical electrical stimulation (ES) has been shown to enhance peripheral nerve regeneration in animal models following axotomy and crush injury. However, whether this treatment is beneficial in humans with sensory nerve injury has not been tested. The goal of this study was to test the hypothesis that ES would enhance sensory nerve regeneration following digital nerve transection compared to surgery alone.

METHODS

Patients with complete digital nerve transection underwent epineurial nerve repair. After coaptation of the severed nerve ends, fine wire electrodes were implanted before skin closure. Postoperatively, patients were randomized to receiving either 1 hour of 20Hz continuous ES or sham stimulation in a double-blinded manner. Patients were followed monthly for 6 months by a blinded evaluator to monitor physiological recovery of spatial discrimination, pressure threshold, and quantitative small fiber sensory testing. Functional disability was measured using the Disability of Arm, Shoulder, and Hand questionnaire.

RESULTS

A total of 36 patients were recruited, with 18 in each group. Those in the ES group showed consistently greater improvements in all sensory modalities by 5 to 6 months postoperatively compared to the controls. Although there was a trend of greater functional improvements in the ES group, it was not statistically significant (p > 0.01).

INTERPRETATION

Postsurgical ES enhanced sensory reinnervation in patients who sustained complete digital nerve transection. The conferred benefits apply to a wide range of sensory functions.

Evaluation of emergency nerve grafting for proper palmar digital nerve defects: a retrospective single centre study

HYPOTHESIS

Finger trauma often results in discontinuity of the proper palmar digital nerves. The goal of this study was to retrospectively evaluate the clinical outcomes of emergency nerve grafting and the resulting donor site morbidity.

MATERIAL AND METHOD

Three women and 13 men who had been operated between 2008 and 2012 were reviewed. The average patient age was 39 years (range 18-78). All were operated on an emergency basis. The average defect was 38 mm long (range 15-60). The nerves were harvested from four sites: lateral antebrachial cutaneous nerve (12 cases), banked finger (2 cases), terminal portion of posterior interosseous nerve (1 case) and anterior interosseous nerve (1 case). The evaluation consisted of patient questioning and clinical examination of the treated finger and donor site. An objective sensory exam was also performed. The results were expressed according to the British Medical Research Council (MRC) classification.

RESULTS

There was little donor site morbidity (2 cases of symptomatic hypoesthesia, 1 case of scar hypersensitivity). Sixty-nine percent of patients stated that their grafted finger did not cause them any trouble during activities of daily living. Three patients required job retraining. Pain in the grafted finger was 0.6 (range 0-5) on the VAS. Normal sensation was restored in 31% of cases based on the monofilament sensory test; 25% had a slight decrease in touch sensitivity and 25% had reduced protective sensations. Weber's two-point discrimination test found 50% normal sensibility (threshold<6mm) and 6% with mediocre sensibility (threshold of 6-10mm). On the MRC grading scale, 50% of patients were at S4, 6% at S3+, 19% at S3, 12% at S2 and 12% at S1.

CONCLUSION

There were 56% good results in this patient series (S3+/S4) and no patients at S0. Donor site morbidity was rare. Thus use of nerve grafting is still a relevant option in an emergency setting.

LEVEL OF EVIDENCE

Level IV.

Comparison of magnification in primary digital nerve repair: literature review, survey of practice trends, and assessment of 90 cadaveric repairs

PURPOSE

To review published clinical outcomes and current practice trends and to assess the quality of cadaveric digital nerve repairs using either loupe or microscopic magnification.

METHODS

Published clinical outcomes of digital nerve repair accounting for magnification level were reviewed. Members of the American Society for Surgery of the Hand were surveyed regarding their current surgical practices. Ninety cadaveric digital nerve repairs were performed by 9 hand surgeons using loupe or microscopic magnification and evaluated by a visual grading scale. Univariate and multivariate analyses were used to evaluate repairs.

RESULTS

We examined 6 publications involving 130 repairs with loupes (4-6×) and 255 repairs with microscopes. Univariate analysis revealed no statistically superior clinical outcomes using high-powered loupes (4-6×) versus microscopic magnification, with no data on lower-magnification loupes more commonly used in practice. Survey data indicated that 52% of hand surgeons use microscopes and 48% use loupes, with 78% using 2.5 to 3.5× magnification. Univariate analysis of the cadaveric repairs demonstrated excellent repairs in 60% of microscope repairs versus 29% of loupe repairs. Multivariate analysis determined that microscopic magnification was 3.9 times more likely than loupes to yield an excellent repair. The surgeon, level of training, repair time, and stitches per repair were not significantly related to an excellent repair.

CONCLUSIONS

Our study indicated that microscope use produces superior quality digital nerve repair. Approximately half of hand surgeons use loupes in current practice, mostly at low magnification (2.5-3.5×). In this context, a higher level of magnification may be positively correlated with better clinical outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Finger sensory reconstruction with transfer of the proper digital nerve dorsal branch

PURPOSE

To report reconstruction of proper digital nerve (PDN) defects using a nerve transfer from the dorsal branch of the uninjured PDN and compare the results with those of nerve grafting.

METHODS

A retrospective study was conducted with 17 consecutive patients who had PDN defects treated with a nerve transfer from the dorsal branch of the PDN from May 2007 to July 2009. The patients included 14 male and 3 female patients, with an average age of 32 years. There were 21 PDN defects in 20 fingers. The injured fingers included 5 index, 8 long, 5 ring, and 2 little fingers. The average length of the nerve defects was 2.3 cm (range, 1.4-3.5 cm). The uninjured dorsal branch of the other PDN of the same digit or the dorsal branch of the PDN of the adjacent digit was selected as a donor nerve. Neurorrhaphy was performed between the dorsal branch and the distal end of the PDN. For comparison, we collected a series of 31 patients with PDN defects treated with conventional sural nerve grafting.

RESULTS

At a mean follow-up of 25 months (range, 20-26 mo), the mean static 2-point discrimination (2PD) and Semmes-Weinstein monofilament (SWM) scores on the finger pulp of the nerve transfer were 6.4 mm and 3.63, respectively. In the comparison group (mean follow-up, 23 mo; range, 19-27 mo), the mean static 2PD and SWM scores on the pulp were 9.2 mm and 4.10 mm. Significant differences were found in static 2PD and SWM results.

CONCLUSIONS

Nerve transfer with the digital nerve dorsal sensory branch was useful for reconstruction of the PDN defect located between the proximal interphalangeal joint and the common digital nerve bifurcation. Sensory recovery using local nerve transfer was superior to conventional sural nerve graft.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Digital nerve injuries: a review of predictors of sensory recovery after microsurgical digital nerve repair

BACKGROUND

Optimal surgical management of digital nerve lesions remains uncertain despite the publication of numerous studies. The purposes of this review were primarily to analyze whether there is a superior surgical technique for digital nerve repair and secondarily to statistically verify the variables to be predictors of sensory recovery.

METHODS

A literature search was performed using PubMed including citation from MEDLINE. Studies were included if they involved patients with digital nerve lacerations in whom end-to-end neurorrhaphy, nerve grafts, conduits, or end-to-side neurorrhaphy were performed. Further, the sensory outcome had to be assessed according to the modified American Society for Surgery of the Hand guidelines to stratify for two-point discrimination in millimeters. The variables age, follow-up, delay in repair, type of trauma, and gap length were extracted. The association between each predictor and response was assessed using a linear mixed model and corrected for heterogeneity between studies. Significance was considered present at p ≤ 0.05.

RESULTS

Of the 34 articles found, 14 articles were included giving appropriate individual data for 191 nerves. There was no statistically significant difference in outcome between operation techniques. Age and follow-up were verified predictors of sensory recovery.

CONCLUSION

In this review, the type of operation for digital nerve repair does not influence sensory outcome. However, we verified outcome to be influenced by the patient's age and the follow-up period. To add more scientific evidence to our results, larger cohort prospective studies need to be done with better detailed description of data.

A comparison between complete immobilisation and protected active mobilisation in sensory nerve recovery following isolated digital nerve injury

Post-operative immobilisation following isolated digital nerve repair remains a controversial issue amongst the microsurgical community. Protocols differ from unit to unit and even, as evidenced in our unit, may differ from consultant to consultant. We undertook a retrospective review of 46 patients who underwent isolated digital nerve repair over a 6-month period. Follow-up ranged from 6 to 18 months. Twenty-four were managed with protected active mobilisation over a 4-week period while 22 were immobilised over the same period. Outcomes such as return to work, cold intolerance, two-point discrimination and temperature differentiation were used as indicators of clinical recovery. Our results showed that there was no significant difference noted in either clinical assessment of recovery or return to work following either post-operative protocol, suggesting that either regime may be adopted, tailored to the patient's needs and resources of the unit.

[Retrospective monocentric comparative evaluation by sifting of vein grafts versus nerve grafts in palmar digital nerves defects. Report of 32 cases]

AIM

Palmar digital nerves defects can be treated by conventional nerve grafts or by means of a conduit, such as a vein. We compared a vein graft technique to a nerve graft technique in a retrospective monocentric study.

MATERIAL AND METHOD

A surgeon who was not involved in the treatment reviewed blind 15 nerve grafts and 17 vein grafts. The evaluation concerned sensitivity, pain, donor site morbidity, social integration and autoassessment of the benefits by the patient. Data were compacted by a sifting method eliminating bad results. The classical functional scores (British Medical Research Council, Möberg, Chanson, Alnot, Dumontier) were also used.

RESULTS

The evaluation was carried out at least 11 months after treatment. Defect was never greater than 30 mm. After sifting, vein grafts appeared less efficient than nerve grafts (41% good results against 73%), except in emergencies (86% good results).

CONCLUSION

For defect loss of no more than 30 mm in emergencies, the authors propose to use vein grafting. In other situations, the surgeon must take into account the patient's profile and the hemi-pulp concerned, dominant or non-dominant, before opting for a nerve or a vein graft.

Postoperative splinting for isolated digital nerve injuries in the hand

Digital nerve injuries in the hand are common and can result in significant impairment and functional restriction. Despite this, there is relatively little literature, particularly with respect to postoperative rehabilitation. Splinting after repair, purported to protect the repaired nerve from excessive stretch is still commonly used. Recent cadaveric studies indicate postoperative rehabilitation is not necessary with resection up to 2.5mm. A randomized controlled trial was therefore undertaken to determine whether splinting after isolated 5th degree digital nerve transection is in fact necessary. Twenty-six subjects were recruited over a two-year period and randomized to either three weeks of hand-based splinting or free active motion. ANCOVA indicated no differences in sensibility at six months between the two groups. Subjects also reported their greatest functional limitations were because of hyperesthesia. Although this study is underpowered, these limited results suggest splinting may not be required postoperatively.

La réparation de pertes de substance des nerves digitaux avec la technique de la greffe veineuse plus interposition de tissu nerveux. Étude prospective et randomisée

OBJECTIVE

This study aims to compare the results of treating digital nerve defects with autologous sural nerve grafts as compared to using a vein conduit with interposition of a posterior interosseous nerve segment.

METHODS

This study is a clinical, prospective, randomized and blinded trial, comparing digital nerve defects treated by two different surgical techniques. It included a total of 50 digital nerves (25 patients in each treatment group), with a mean follow up of 10.2 (SD 1.4) months. In addition, the impact of five different factors (type of surgery, size of nerve defect, patient's age, type of lesion and lesion age) on the final outcome were evaluated.

RESULTS

In respect of the sensory assessment, the static two point discrimination score was 6 mm for both groups . According to the Al-Ghazal Scoring Method, the autolougus sural nerve graft group scored a mean (sd) of 7.7 (1.9) points, while vein conduit with interposition of a posterior interosseous nerve segment group scored 6.9 (2.1). Under multivariate analysis, both patient's age and lesion age proved to be important independent factors, having influenced almost all results. The group treated with vein conduit with interposition of a posterior interosseous nerve segments showed fewer complications than the group treated using sural nerve.

CONCLUSION

Based on the results obtained, we concluded that the sensory scores were equal in both groups. We also concluded that the vein conduit and posterior interosseous nerve graft procedure offered some advantages in terms of the complication rate.

Rehabilitation of digital nerve repair: is splinting necessary?

Forty isolated, sharp digital nerve divisions, which had been repaired by microsurgical techniques, were reviewed between 12 and 36 months postoperatively (mean, 20 months). Half of the repairs had been splinted beyond the immediate postoperative period and half had not. Non-splinted patients returned to work significantly quicker than those who were splinted. Splinted patients reported more stiffness and cold intolerance but splinting made no difference to either the measured sensibility or movement of the digit. We would conclude that, after repair of sharp, uncomplicated digital nerve divisions, splinting beyond the immediate postoperative period is at least unnecessary and may be deleterious.

Alleviated tension at the repair site enhances functional regeneration: the effect of full range of motion mobilization on the regeneration of peripheral nerves--histologic, electrophysiologic, and functional results in a rat model

BACKGROUND

In the clinical management of combined tendon and nerve injuries, competing treatment strategies are well known. The effect of mobilization on the functional regeneration of peripheral nerves remains controversial. This study sought to determine the effect of full range of motion mobilization on nerve repair by using tubular segmental nerve splinting to block movement, and thereby variable tension, at the nerve repair site.

METHODS

In 96 rats, the right sciatic nerve was transected midthigh and coapted immediately microsurgically. The groups used in the study were as follows: group N, epineural nerve repair; group T, segmental tubular nerve splinting with fixed in situ tension at the nerve suture site,allowing segmental movement only; group TN, segmental tubular nerve splinting with alleviated in situ tension at the nerve suture site, allowing segmental movement only; and group TM, segmental tubular nerve splinting without fixed in situ tension at the nerve suture site, allowing movement of the nerve suture site. Full range of motion of the lower limbs was ensured by passive motion of hind limbs once a week after functional testing. Blinded histologic, immunohistochemical, and electrophysiologic assessment and 12 postoperative weekly function tests were carried out.

RESULTS

Functional and electrophysiologic results were significantly better in group TN, by segmental tubular nerve splinting with alleviated in situ tension at the nerve repair site, mainly because of less scar formation and enhanced endoneural angiogenesis at the nerve suture segment.

CONCLUSION

Full range of motion mobilization may impede functional nerve recovery by significant endoneural collagenization and decreased angiogenesis at the nerve suture segment. Complete alleviation of in situ (pathophysiologic) tension at the nerve suture site seems to improve functional peripheral nerve regeneration.

Effects of tobacco smoke on recovery after nerve crush injury in rats

The effects of tobacco smoke on nerve healing after crush injury was studied in a rat model. Thirty-six animals were randomized equally into smoke-exposed or nonsmoke-exposed groups. Two nerve crush injuries were performed on the right posterior tibial nerve of each animal at 4-week intervals to mimic a sustained or chronic nerve injury. Recovery of the two groups was assessed with walking track analysis and nerve histomorphometry. There was no difference in the rate of nerve recovery based on walking track analysis in the smoke-exposed animals compared with nonexposed animals. The study also failed to demonstrate any significant difference between the two groups as assessed by histomorphometric criteria.

A prospective study of early tactile stimulation after digital nerve repair

Forty-nine patients with 65 digital nerve injuries were randomized into two groups after nerve repair. Group 1 received early tactile stimulation and Group 2 was a control group. The patients were assessed prospectively for 6 months for recovery of functional sensibility. Tactile stimulation in Group 1 was provided from 3 weeks after nerve repair with a specially designed rotating tactile stimulator and a pocket tactile stimulator. Constant two-point discrimination, moving two-point discrimination, and cutaneous pressure threshold were measured and sensibility was graded with the Medical Research Council (UK) sensibility grading. At 6 months, 68.8% of patients in Group 1 had a Medical Research Council grading of S3+ or S4 sensibility compared with 36 % in Group 2. With this prospective randomized study, the value of sensory reeducation in improving sensibility after digital nerve injury was confirmed. Starting tactile stimulation from the early postoperative period is recommended; however, use of the rotating tactile stimulator and pocket tactile stimulation need additional study.

Objective assessment of post-traumatic nerve repairs and neuromas

The assessment of a nerve repair usually focuses on the level of sensory and motor recovery distal to the site of the repair. However, the development of a painful neuroma or nerve junction, particularly in a digit, can be just as disabling to the patient as an area of anaesthesia. An instrument has been developed to assess objectively the severity of neuroma formation at nerve-repair sites by measuring the threshold percussive force required to elicit a Tinel's sign using standard weights dropped from a uniform height in a tube.

A randomized prospective study of polyglycolic acid conduits for digital nerve reconstruction in humans

This article reports the first randomized prospective multicenter evaluation of a bioabsorbable conduit for nerve repair. The study enrolled 98 subjects with 136 nerve transections in the hand and prospectively randomized the repair to two groups: standard repair, either end-to-end or with a nerve graft, or repair using a polyglycolic acid conduit. Two-point discrimination was measured by a blinded observer at 3, 6, 9, and 12 months after repair. There were 56 nerves repaired in the control group and 46 nerves repaired with a conduit available for follow-up. Three patients had a partial conduit extrusion as a result of loss of the initially crushed skin flap. The overall results showed no significant difference between the two groups as a whole. In the control group, excellent results were obtained in 43 percent of repairs, good results in 43 percent, and poor results in 14 percent. In those nerves repaired with a conduit, excellent results were obtained in 44 percent, good results in 30 percent, and poor results in 26 percent (p = 0.46). When the sensory recovery was examined with regard to length of nerve gap, however, nerves with gaps of 4 mm or less had better sensation when repaired with a conduit; the mean moving two-point discrimination was 3.7 +/- 1.4 mm for polyglycolic acid tube repair and 6.1 +/- 3.3 mm for end-to-end repairs (p = 0.03). All injured nerves with deficits of 8 mm or greater were reconstructed with either a nerve graft or a conduit. This subgroup also demonstrated a significant difference in favor of the polyglycolic acid tube. The mean moving two-point discrimination for the conduit was 6.8 +/- 3.8 mm, with excellent results obtained in 7 of 17 nerves, whereas the mean moving two-point discrimination for the graft repair was 12.9 +/- 2.4 mm, with excellent results obtained in none of the eight nerves (p < 0.001 and p = 0.06, respectively). This investigation demonstrates improved sensation when a conduit repair is used for nerve gaps of 4 mm or less, compared with end-to-end repair of digital nerves. Polyglycolic acid conduit repair also produces results superior to those of a nerve graft for larger nerve gaps and eliminates the donor-site morbidity associated with nerve-graft harvesting.

Clinical assessment of primary digital nerve repair

We have carried out a retrospective study of 64 primary digital nerve repairs in 50 patients who presented to our department between 1988 and 1993. 45 of the patients were operated on within 6 hours of the injury using microscope (x 14). Normal two-point discrimination was regained in only 9 cases, while 6-10 mm two-point discrimination was achieved in 22, 11-15 mm in 15 and protective sensation in 18. A close correlation between age and recovery of sensation after repair was observed. Microsurgical repair of digital nerve gives satisfactory results, since a normal or good two-point discrimination can be obtained in about half of cases, while sensation improves in the rest. A high rate of complete recovery of sensation, however, is to be expected only in children.