Digital Nerve Repair Research Articles

Fibrin Glue Increases the Tensile Strength of Conduit-Assisted Primary Digital Nerve Repair.

An ideal peripheral nerve repair construct does not currently exist. Our primary goal was to determine whether fibrin glue adds to the tensile strength of conduit-assisted primary digital nerve repairs. Our secondary goal was to evaluate the impact of varying suture number and location on the tensile strength. Ninety cadaveric digital nerves were harvested and divided equally into the following repair groups: A (4/4), B (2/2), C (0/2), D (0/1), and E (0/0) with the first number referring to the number of sutures at the coaptation and the second number referring to the number of sutures at each proximal and distal end of the nerve-conduit junction. When fibrin glue was added, the group was labeled prime. The nerve specimens were transected and then repaired with 8-0 nylon suture and conduit. The tensile strength of the repairs was tested, and maximum failure load was determined. The results were analyzed with a 2-way analysis of variance. The Tukey post hoc test compared repair groups if the 2-way analysis of variance showed significance. Both suture group and glue presence significantly affected the maximum failure load. Increasing the number of sutures increased the maximum failure load, and the presence of fibrin glue also increased the failure load. Fibrin glue was found to increase the strength of conduit-assisted primary digital nerve repairs. Furthermore, the number of sutures correlated to the strength of the repair. Fibrin glue may be added to a conduit-assisted primary digital nerve repair to maintain strength and allow fewer sutures at the primary coaptation site.

Postoperative Evaluation of Patient Satisfaction and Tingling Sensation after Replantation Surgery without Nerve Repair for Complete Digital Amputation

Background When performing replantation surgery for complete fingertip amputation, we do not perform digital nerve repair. We hypothesized that this method would not decrease patient satisfaction. Methods Between July 2011 and August 2013, we performed replantation surgery for 21 complete digital amputations in 18 patients. Digital nerves were not repaired for fingertip amputations. For proximal to distal interphalangeal joint amputations (proximal amputation), however, we repaired as many digital nerves as possible. We followed 17 replanted fingers in 14 patients (fingertip, 9 fingers in 9 patients; proximal, 8 fingers in 5 patients) for > 1 year, performing retrospective evaluation of subjective outcomes via telephone surveys. Patient satisfaction and fingertip tactile sensation scores (FTSS) were rated on scales of 0 to 10; unpleasant sensations (paresthesia or dysesthesia) were also surveyed. Results Mean patient satisfaction was significantly greater in the fingertip-amputation group than in the proximal-amputation group (9.4 and 7.6, respectively), although mean FTSS did not show significant difference (6.0 and 3.6, respectively). Patients with proximal amputations had dysesthesia in three fingers, paresthesia in one finger, and no numbness in four fingers, whereas patients with fingertip amputations had dysesthesia in three fingers, paresthesia in four fingers, and no numbness in two fingers. Patients with fingertip amputation had significantly more unpleasant sensation than those with proximal amputations. Conclusion Although fingertip replantation without digital nerve repair causes postoperative tingling, it results in good patient satisfaction.

The Intraneural Hemangioma of the Digital Nerve: Case Report

Intraneural Hemangioma of the digital nerve is rare and so far three cases have been reported in the literature. We present a case of 12- year- old boy with painless soft tissue mass in the right hand and numbness on the radial aspect of the index finger. Magnetic Resonance Imaging showed an isointense subcutaneous lesion without discrete borders in the first web space classically of hemangioma with the radial digital nerve extension. On exploration, the intraneural extension of the hemangioma was confirmed and total resection, microsurgical primary digital nerve repair was done. The patient became better and at 6months follow up the index finger sensation improved. The patient had no reccurence and he is still under follow up.

Resistance of primary microsurgical repair of palmar digital nerves to finger mobilization: A cadaver study

The aim of this study was to assess the resistance of microsurgically repaired proper palmar digital nerves (PPDN) to mobilization. Thirty-nine PPDN from fresh forearms cadavers were transected and then sutured using 10/0 nylon. After skin closure, each finger was forcefully flexed and extended 10 times. Out of the 39 repaired nerves, two were elongated and four were ruptured; this amounts to a 15.38% complication rate. We recommend immobilization of nerve repairs, although this contradicts most recent studies.

A modified digital nerve repair technique in replantation of rotational avulsed fingers

Objective To modify the conventional technique for repairing digital nerve in replantation of avulsed fingers, and to evaluate its clinical outcomes. Methods From August 2011 to June 2015, 12 cases of avulsed fingers were replanted. The avulsed digital nerve on one side was harvested as a graft for repair of the digital nerve on the other side. The distal donor digital nerve was then sutured to digital nerve of the recipient side in an end-to-side fashion. Results All 12 replanted fingers survived uneventfully with primary wound healing.All the patients were follow-up for 12 to 18 months. Perfusion, appearance and function of the replanted fingers were good. Pain sensation and temperature sensation returned. Two-point discrimination was 4 to 9 mm on the graft repair side of finger pulp, equivalent to S3+ to S4. Sensory recovery on the end-to-side neurorrhaphy side was S3 to S3+. According to the criteria for functional assessment of replanted fingers issued by the Hand Surgery Society of Chinese Medicine Association, the results were excellent in 7 cases and good in 5 cases. Conclusion In replantation of avulsed fingers, sensory restoration of the pulp can be achieved by using a segment of the digital nerve from one side to graft repair digital nerve of the other side while suturing the distal donor digital nerve to the graft repair digital nerve in an end-to-side fashion. Key words: Fringer injuries; Replantation; Nerve grafting

A Multicenter, Prospective, Randomized, Pilot Study of Outcomes for Digital Nerve Repair in the Hand Using Hollow Conduit Compared With Processed Allograft Nerve.

Current repair options for peripheral nerve injuries where tension-free gap closure is not possible include allograft, processed nerve allograft, and hollow tube conduit. Here we report on the outcomes from a multicenter prospective, randomized, patient- and evaluator-blinded, pilot study comparing processed nerve allograft and hollow conduit for digital nerve reconstructions in the hand. Across 4 centers, consented participants meeting inclusion criteria while not meeting exclusion criteria were randomized intraoperatively to either processed nerve allograft or hollow conduit. Standard sensory and safety assessments were conducted at baseline, 1, 3, 6, 9, and 12 months after reconstruction. The primary outcome was static 2-point discrimination (s2PD) testing. Participants and assessors were blinded to treatment. The contralateral digit served as the control. We randomized 23 participants with 31 digital nerve injuries. Sixteen participants with 20 repairs had at least 6 months of follow-up while 12-month follow-up was available for 15 repairs. There were no significant differences in participant and baseline characteristics between treatment groups. The predominant nerve injury was laceration/sharp transection. The mean ± SD length of the nerve gap prior to repair was 12 ± 4 mm (5-20 mm) for both groups. The average s2PD for processed allograft was 5 ± 1 mm (n = 6) compared with 8 ± 5 mm (n = 9) for hollow conduits. The average moving 2PD for processed allograft was 5 ± 1 mm compared with 7 ± 5 mm for hollow conduits. All injuries randomized to processed nerve allograft returned some degree of s2PD as compared with 75% of the repairs in the conduit group. Two hollow conduits and one allograft were lost due to infection during the study. In this pilot study, patients whose digital nerve reconstructions were performed with processed nerve allografts had significantly improved and more consistent functional sensory outcomes compared with hollow conduits.

Does crossover innervation really affect the clinical outcome? A comparison of outcome between unilateral and bilateral digital nerve repair.

Digital nerve injuries are the mostly detected nerve injury in the upper extremity. However, since the clinical phenomenon of crossover innervation at some degree from uninjured digital nerve to the injured side occurs after digital nerve injuries is sustained, one could argue that this concept might even result in the overestimation of the outcome of the digital nerve repair. With this knowledge in mind, this study aimed to present novel, pure, focused and valuable clinical data by comparing the outcomes of bilateral and unilateral digital nerve repair. A retrospective review of 28 fingers with unilateral or bilateral digital nerve repair using end-to-end technique in 19 patients within 2 years was performed. Weber's two-point discrimination, sharp/dull discrimination, warm/cold sensation and Visual Analog Scale scoring were measured at final 12-month follow ups in all patients. There was no significant difference in recovery of sensibility after unilateral and bilateral digital nerve repairs. Though there is crossover innervation microscopically, it is not important in the clinical evaluation period. According to clinical findings from this study, crossover innervations appear to be negligible in the estimation of outcomes of digital neurorrhaphy.

Flexor pollicis longus repair in a patient with Linburg-Comstock anomaly: A case report

Background: We present a patient with this anomaly who sustained a saw cut injury to his hand resulting in severance of the FPL and bilateral digital nerves of the thumb. Methods: A 36-year old male laborer who sustained a saw cut injury to his dominant right hand presented to the emergency department. The wound extended from the skin edge of the first web to the base of first metacarpal in the palm at Urbaniak zone 3. The FPL tendon and both digital nerves were cut. In the operating room, the wound was enlarged with Z incisions and a dissection deep into the wound was conducted. The cut end of the FPL tendon was found and secured using a different technique. Bilateral digital nerve repair was performed with interpositional grafting of the lateral antecubital cutaneous nerve bundles. Results: At the end of the rehabilitation program, the thumb recovered full range of motion, and physical examination revealed synchronous flexion movement (synkinesis) of the thumb and index finger. Conclusion: Flexor pollicis longus tendon lacerations are common in the clinical practice of hand surgeons. Making a separate proximal wrist incision is a very useful technique to reach a proximal tendon stump. Otherwise, aggressive maneuvers may cause additional damage to the tendons involved and result in unpredicted outcomes. The attempts to retrieve the tendon at the injury site resulted in failure and gave a tethering sensation to the surgeon who recalled the Linburg-Comstock anomaly.

Outcome of Repaired Digital Nerve Injuries in Children – Influence of Age in a Retrospective Long-Term Follow-Up: Level 4 Evidence

Do children with a repaired digital nerve injury regain normal sensation and hand function and does age correlate with outcome? Eighty-two children, aged 1-16 years at the time of injury, were treated for a digital nerve injury between 2002-2009 at our department. All children were invited for a follow up, including clinical evaluation (Semmes-Weinstein monofilaments, grip strength, VAS for function and cosmetic) and questionnaires (QuickDASH, CISS). Thirty-eight children (46%) accepted and outcome was evaluated at a median of 40 months (range 12-131 months) after the injury. The study population was divided into two groups – a young group (n=18) with age 0-10 years and an older group (n=20) with age 11-16 years. Most children were boys, who were injured at home and by a cut. The level of digital nerve injury was in 20/38 (53%) patients distal to the PIP-joint and the remaining patients had an injury between the PIP-joint and the distal volar crease. The index finger was the most frequently injured finger. The median Hand Injury Severity Score (HISS) was 37 (8-137). All patients regained normal sensation based on monofilament test with limited affected hand function, although some cold sensitivity remained. We found no significant difference between younger and older children concerning HISS, Cold Sensitivity Severity Scale (CISS), QuickDASH, VAS or grip power. No correlation between age and perception of touch (i.e. monofilament test) was found. •Children (0-16 years) have an excellent recovery after a digital nerve injury and repair.•Age of the children did not affect outcome.•The majority of children have some degree of cold sensitivity.•No major hand disability was found irrespective of age.

Comparison of Functional Recovery Outcomes by Gap between Processed Nerve Allograft and Hollow Tube Conduits for Digital Nerve Repairs: Level 3 Evidence

Comparison of Functional Recovery Outcomes by Gap between Processed Nerve Allograft and Hollow Tube Conduits for Digital Nerve Repairs: Level 3 Evidence

Shocking therapy: Brief electrical stimulation for delayed nerve repair

This commentary provides perspective on a recent paper published in Experimental Neurology by Elzinga et al. where the authors investigated the effect of brief electrical stimulation (ES) on nerve regeneration after delayed nerve repair in a rodent model. Their results from a well controlled series of experiments indicated that brief ES promoted axonal outgrowth after chronic axotomy as well after chronic Schwann cell and muscle denervation. ES also increased chronically axotomized neurons regenerating into chronically denervated stumps, which represent a true delayed repair. The authors conclude that brief ES promotion of nerve regeneration after delayed nerve repair is as effective as after immediate repair. Given the prior experimental evidence, and the prior clinical data from patients with carpal tunnel syndrome and digital nerve repair, the implication of this new work is to consider a well designed clinical trial for use of brief ES in nerve graft and nerve transfer repairs.

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. IV.

Prognostic factors in sensory recovery after digital nerve repair.

The prognostic factors that affect sensory nerve recovery after digital nerve repair are variable because of nonhomogeneous data, subjective tests, and different assessment/scoring methods. The aim of this study was to evaluate the success of sensory nerve recovery after digital nerve repair and to investigate the prognostic factors in sensorial healing. Ninety-six digital nerve repairs of 63 patients were retrospectively evaluated. All nerves were repaired with end-to-end neurorraphy. The static two-point discrimination (s2PD) and Semmes Weinstein monofilament (SWM) tests were performed to evaluate sensory recovery. The association between prognostic factors such as gender, age, involved digit, time from injury to repair, length of follow-up, smoking, concomitant injuries, type of injury, and sensory recovery results were assessed. The s2PD test demonstrated excellent results in 26 nerves (27%), good results in 61 nerves (64%), and poor results in 9 nerves (9%). The results of the SWM test according to Imai classification showed that 31 nerves (32%) were normal, light touch was diminished in 38 nerves (40%), protective sensation was diminished in 17 nerves (18%), loss of protective sensation occurred in 5 nerves (5%), and 5 nerves (5%) were anesthetic. There was a negative relationship between age, smoking, concomitant injuries, and sensory recovery. Our results demonstrate that concomitant tendon, bone and vascular injuries, older age, and smoking were associated with worse sensory nerve recovery results. However, all digital nerve injuries should be repaired, regardless of these prognostic factors.

Comparison of short- with long-term regeneration results after digital nerve reconstruction with muscle-in-vein conduits.

Muscle-in-vein conduits are used alternatively to nerve grafts for bridging nerve defects. The purpose of this study was to examine short- and long-term regeneration results after digital nerve reconstruction with muscle-in-vein conduits. Static and moving two-point discriminations and Semmes-Weinstein Monofilaments were used to evaluate sensory recovery 6–12 months and 14–35 months after repair of digital nerves with muscle-in-vein in 7 cases. Both follow-ups were performed after clinical signs of progressing regeneration disappeared. In 4 of 7 cases, a further recovery of both two-point discriminations and in another case of only the static two-point discrimination of 1–3 mm could be found between the short-term and long-term follow-up examination. Moreover, a late recovery of both two-point discriminations was demonstrated in another case. Four of 7 cases showed a sensory improvement by one Semmes-Weinstein Monofilaments. This pilot study suggests that sensory recovery still takes place even when clinical signs of progressing regeneration disappear.

Prognostic Factors in Sensory Recovery of Digital Nerve Repair

Prognostic Factors in Sensory Recovery of Digital Nerve Repair

Sensory recovery after primary repair of palmar digital nerves using a Revolnerv® collagen conduit: A prospective series of 27 cases

Despite advances in microsurgery, digital nerve repair remains a challenge due to the lack of reproducible procedures with satisfactory functional results. The aim of this study was to compare the sensory and functional results of direct microsurgical sutures protected by a Revolnerv® nerve regeneration conduit, with results of a series of direct sutures without a protective conduit in the literature. From November 2009 to April 2010, 35 patients were treated by direct epiperineural suture for digital nerve injury, protected by a Revolnerv® nerve regeneration conduit at the FESUM centre “SOS-mains Lesquin/CHRU de Lille”. Sensory recovery was assessed by the static two-point discrimination Weber test (WS) and the Semmes-Weinstein (SW) test at postoperative months 1, 3, and 6. The final evaluation was performed after a minimum follow-up of 6 months. Statistical analysis of sensory results (WS and SW) was mainly performed with non-parametric tests (Wilcoxon, Mann and Whitney). P<0.05 was considered to be statistically significant. One patient was excluded, six were lost to follow-up, and four could not be seen at the 6-month follow-up visit. Finally, 24 patients and 27 nerve sutures were included. Mean age was 38 years old and the ratio of women/men was 1/5. Eighty-five percent of the patients had useful (S3+) or normal (S4) discrimination at 6 months, and the average WS was 10.3 (±3.76). There was a tendency to better WS results in sharp transections compared to jagged lacerations (9.19 vs 11.82). The SW test was satisfactory in 15% of patients and acceptable in 30%. There were no complications from the Revolnerv® collagen tube. After 6 months follow-up this study shows that results with the Revolnerv® nerve regeneration conduit on direct palmar digital nerve sutures were comparable to but not better than those of uncoated direct sutures. A study including a larger population with longer follow-up is necessary to determine the value of this technique and its recommendation for general use in all digital nerve injuries.

Cortical Integration of the Free Transferred Toes in Posttraumatic Hand Reconstruction

Introduction: Reconstruction of the thumb and complex hand mutilations with fingers amputation are best solved by microsurgical transferring the toes. Transferred toes-to-hand will be innervated much better than they were in the donor site, performance explained by both the higher number of nerve fibers in the digital nerves of the hand comparative to the toes and cortex plasticity. Suite phenomena occurring in cortical integration of the microsurgical transferred toes-to-hand is comparable to that following the digital nerve repair or replantation.

Is there a profit to use the lateral antebrachial cutaneous nerve as a graft source in digital nerve reconstruction?

The digital nerves are commonly injured in emergency hand surgery practice. Lateral antebrachial nerve is of the autologous graft options available in forearm for digital nerve reconstruction. In this report, we aimed the evaluation of this nerve as an autologous nerve source for digital nerve repair. The overall sensorial results of the lateral antebrachial cutaneous nerve grafting and associated donor site morbidity in neglected digital nerve injuries of 15 patients in Zones 1 and 2 were evaluated Average length of the harvested lateral antebrachial cutaneous nerve grafts was 1.81 cm (0.75-3 cm.). Patients have been followed up for 20.7 months in average (range: 9.3-41 months). According to Highet and Sander criteria modified by Mackinnon and Dellon, nine patients were graded as S4, whereas six patients had S3+ values. According to modified ASSH guidelines for stratification of static 2PD results, excellent results were obtained in five patients, good results were achieved in eight patients and moderate results were obtained in two patients. Both the donor and recipient sites were evaluated with Semmes-Weinstein monofilament tests where satisfactory results have been obtained. Only two patients reported minimal cold intolerance at the donor site apart from the mild hypoesthesia noted at the anterolateral aspect of the middle forearm. Quite favorable clinical results with minimal donor site sensorial deficiency, anatomical and histomorphological similarity and being available in close location to surgical area brings up a matter to utilization of LABCN for digital nerve reconstruction.

Prospective Clinical Study on Digital Nerve Repair with Collagen Nerve Conduits and Review of Literature

Little data are available concerning conduit repair of digital nerve lesions. We are presenting a prospective two-center cohort study on digital nerve reconstruction with collagen nerve conduits. The data are put into the context of a comprehensive review of existing literature. Over a period of 3 years, all consecutive digital nerve lesions that could not be repaired by tensionless coaptation with a gap length of less than 26 mm were reconstructed with nerve conduits made from bovine collagen I. Sensibility was assessed 1 week, 3, 6, and 12 months postoperatively by static and moving 2-point-discrimination (2PD) and monofilament testing. Forty-nine digital nerve lesions in 40 patients met the inclusion criteria. The mean nerve gap was 12.3 ± 2.3 mm (span 5-25 mm). Forty nerve reconstructions could be included in the 12-month follow-up. Three cases, assessed 12 months postoperatively, showed excellent sensibility (static 2PD <6 mm). Seventeen achieved good (2PD 6-10 mm), 5 fair (2PD 11-15 mm), 6 poor (2PD >15 mm, but protective sensibility), and 9 achieved no sensibility. Monofilament test results were significantly better if gap length was shorter than 12 mm. Our results confirm tubulization as one possible technique in nerve reconstruction for gap lengths of 5 to 25 mm.

Essential Hand Surgery Procedures for Mastery by Graduating Plastic Surgery Residents

This study was designed to establish the essential hand surgery procedures that should be mastered by graduating plastic surgery residents. This framework can then be used as a guideline for developing Objective Structured Assessment of Technical Skill to teach technical skills in hand surgery. Ten expert hand surgeons were surveyed regarding the essential hand surgery procedures that should be mastered by graduating plastic surgery residents. The top 10 procedures from this survey were then used to survey all 89 Accreditation Council for Graduate Medical Education-approved plastic surgery program directors. There was a 69 percent response rate to the program director survey (n = 61). The top nine hand surgery procedures included open carpal tunnel release, open A1 pulley release, digital nerve repair with microscope, closed reduction and percutaneous pinning of metacarpal fracture, excision of dorsal or volar ganglion, zone II flexor tendon repair with multistrand technique, incision and drainage of the flexor tendon sheath for flexor tenosynovitis, flexor tendon sheath steroid injection, and open cubital tunnel release. Surgical educators need to develop objective methods to teach and document technical skill. The Objective Structured Assessment of Technical Skill is a valid method for accomplishing this task. There has been no consensus regarding which hand surgery procedures should be mastered by graduating plastic surgery residents. The authors have identified nine procedures that are overwhelmingly supported by plastic surgery program directors. These nine procedures can be used as a guideline for developing Objective Structured Assessment of Technical Skill to teach and document technical skills in hand surgery.