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Background: Digital nerves will experience tension under normal daily activities, and understanding the amount of tension experienced in these nerves relates directly to the necessary strength in nerve repairs. To begin quantification of tension, the tension borne by the median and digital nerves in cadaveric hands was quantified under conditions of finger hyperextension, nerve distraction, and finger flexion. Methods: Five cadaveric hands were mounted in a special fixture that allowed finger hyperextension and flexion and could apply known distractions while the tension borne by each digital nerve was measured. Sequential dissection exposed the digital nerves so that measurements of tension in the median, common, and proper digital nerves were conducted with finger hyperextension, nerve distraction, and finger flexion. Results: Metacarpophalangeal (MCP) hyperextension of 30° created mean nerve tensions up to 0.64 N, 5 mm of nerve distraction created mean nerve tensions up to 1.23 N, and 90° of MCP flexion relieved up to a mean of 1.18 N of nerve tension. Conclusions: In situ tension is present in the median and digital nerves with digital motion. Finger hyperextension and nerve distraction produce tension, whereas finger flexion reduces tension. Existing nerve repairs are strong enough to withstand in situ nerve tensions produced by reasonable digital motion if the original nerve length is present.

The digital nerve block is an effective method of anesthesia before minor surgical interventions on the fingers. However, patients may experience a lot of pain and anxiety during this procedure. The efficacy of topical vapocoolant spray during minor procedures has been demonstrated in previous studies. we aimed to evaluate the effectiveness of topical vapocoolant spray in reducing pain during digital nerve block.This prospective, randomized clinical study was conducted to evaluate the effectiveness of vapocoolant spray application in reducing pain during digital block. The patients were categorized into 2 groups as spray-treated and control group. A routine digital block process was applied to the control group. Spray application was performed in two groups of 50 each, in a manner of bilateral and unilateral to the finger. Demographic data of the patients, such as gender, age, dominant hand, injury patterns, injection site and injury sites, were recorded. After the application, the patients' visual analog scale (VAS) was evaluated.Of the participants, 100 were randomly assigned to the vapocoolant spray-treated group, and 50 were included in the control group. The VAS pain score during penetration in both spray groups was significantly lower than the control group (p0.001). Pain change during penetration was found to be significantly lower in the bilateral spray-treated group compared to the control group (p0.001). Pain change during infiltration was significantly lower in both spray groups compared to the control group (p0.001).Spray application prior to digital nerve blocking can be used to reduce needle penetration pain associated with this procedure and pain associated with local anesthetic infiltration.

The goal of this systematic review and meta-analysis was to compare nerve conduits and nerve graft for peripheral nerve regeneration. This type of lesion frequently causes disability due to pain, paresthesia and motor deficit. On the PICO process, "P" corresponded to patients with peripheral digital nerve lesions of any age, gender or ethnicity, "I" to interventions with nerve conduits or nerve graft, "C" to the control group with no treatment, placebo or receiving other treatment, and "O" to outcome assessment of nerve regeneration. Initial search found in 3859 studies, including 2001 duplicates. The remaining 1858 studies were selected by title and/or abstract; 1798 articles were excluded, leaving 60 articles for full-text review. Thirty-nine of these 60 reports were excluded as not meeting our inclusion criteria, and 21 articles were ultimately included in the systematic review. For patients older than 40 years, there was a greater mean improvement on S2PD and M2PD tests with grafting, which seemed to be the better surgical technique, positively impacting prognosis. On the M2PD test, there was significantly greater improvement in 11-17.99 mm defects with grafting (P 0.001); this finding should guide surgical strategy in peripheral nerve regeneration, to ensure better outcomes.

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.

Purpose Biomaterials used to restore digital nerve continuity after injury associated with a defect may influence ultimate outcomes. An evaluation of matched cohorts undergoing digital nerve gap reconstruction was conducted to compare processed nerve allograft (PNA) and conduits. Based on scientific evidence and historical controls, we hypothesized that outcomes of PNA would be better than for conduit reconstruction. Methods We identified matched cohorts based on patient characteristics, medical history, mechanism of injury, and time to repair for digital nerve injuries with gaps up to 25 mm. Data were stratified into 2 gap length groups: short gaps of 14 mm or less and long gaps of 15 to 25 mm. Meaningful sensory recovery was defined as a Medical Research Council scale of S3 or greater. Comparisons of meaningful recovery were made by repair method between and across the gap length groups. Results Eight institutions contributed matched data sets for 110 subjects with 162 injuries. Outcomes data were available in 113 PNA and 49 conduit repairs. Meaningful recovery was reported in 61% of the conduit group, compared with 88% in the PNA group. In the group with a 14-mm or less gap, conduit and PNA outcomes were 67% and 92% meaningful recovery, respectively. In the 15- to 25-mm gap length group, conduit and PNA outcomes were 45% and 85% meaningful recovery, respectively. There were no reported adverse events in either treatment group. Conclusions Outcomes of digital nerve reconstruction in this study using PNA were consistent and significantly better than those of conduits across all groups. As gap lengths increased, the proportion of patients in the conduit group with meaningful recovery decreased. This study supports the use of PNA for nerve gap reconstruction in digital nerve reconstructions up to 25 mm. Type of study/level of evidence Therapeutic III.

The purpose of this study is to determine how loss of sensation affect hand dexterity. In this study, digital nerve block anaesthesia was performed in different stages of timing for thumb, index and middle fingers of 12 volunteers. The Moberg pick-up test was conducted in the assessment of hand dexterity. Grip and pinch forces were also measured. Loss of thumb sensation had the greatest effect on dexterity, increasing average timing by at least 10.5 seconds (range 3.4 to 32.4). Loss of sensation to the index and middle fingers has a lesser impact, but decreased hand grip and chuck pinch forces (grip –25% or –33%, chuck pinch –31% or –32% depending on the timing of injections). We concluded that loss of thumb sensation has the greatest impact on hand dexterity. Index and middle finger sensory loss had less of an impact on hand dexterity but decreased grip and chuck pinch forces. Level of evidence: IV

Dislocations of thumb interphalangeal (IP) joint are rare injuries due to inherent stability of the joint. This report presents a case of complex irreducible dorsal IP joint dislocation of thumb due to interposition of four structures – volar plate, sesamoid bone, flexor pollicis longus tendon and digital nerve which is perhaps the only case reported so far in literature where more than three structures have been implicated for this joint irreducibility. The author presents a comparative review of similar case reports previously reported in literature listing the controversies in management and forming a broad consensus in the management of these difficult injuries. Finally, an algorithm for the management of these injures has been proposed in this article which maybe helpful for other operators in tackling these injuries so as to deliver predictable treatment outcomes.

Introduction Proximal interphalangeal joint (PIP) is one of the joints exposed to upper limb injury. The dorsal fracture-dislocations of the PIP is a common injury. Treatment of cases with small avulsed bone fragments is challenging. Stable fixation with rapid recovery is important in these patients. Hypothesis Volar buttress plating a new technique in treatment of the dorsal proximal interphalangeal joint fracture dislocations but the results of it is unknown. Methods In this case series, 21 patients with dorsal fracture-dislocations of the proximal interphalangeal were studied. We used a volar hook plate buttressing technique so that fixation was done by low-profile 2-mm stainless steel hook plate with a 1.5-mm screw. Range of motion movements, power and grip strength were measured after 3 months. At end of follow-up period, functional outcome was determined by the visual analogue scale, Quick Disabilities of the Arm, Shoulder, and Hand. Results After three-month follow-up a union of fractures occurred in all of the patients. There were no complications, such as infection, digital nerve injuries or flexor tendon rupture. The joints range of motion were stable and had no restrictions. Postoperative range of motion outcome in 19 (90.5%) patients was 85.7 ± 13.2 degree which was not significantly different from opposite side on other hand (p = 0.1). In two patients range of motion was 65.5 ± 5.4 degree and painful. Postoperative pain in 19 patients was 2.5 ± 0.8 so that there was no pain in 17(76.2%) patients, three (14.1%) patients had mild pain and two (9.5%) patients had moderate pain (5.4 ± 1.2). Two patients complained of plate irritation of especially at end of proximal intrphalangeal flexion. Conclusion Clinical application of hook plate buttressing technique induced stable fixation and rapid recovery. Because of maintaining articular congruity and restoring anatomically, this technique associated with good outcomes. Level of Evidence IV, Therapeutic study.

Rationale and Objectives The medial plantar proper digital nerve, also called Joplin's nerve, arises from the medial plantar nerve, courses along the medial hallux metatarsophalangeal joint, and can be a source of neuropathic pain due to various etiologies, following acute injury including bunion surgery and repetitive microtrauma. We describe our clinical experience with diagnostic ultrasound assessment of Joplin's neuropathy and technique for ultrasound-guided therapeutic intervention including both injection and cryoablation over a 6-year period. Materials and Methods Retrospective review of all diagnostic studies performed for Joplin's neuropathy and therapeutic Joplin's nerve ultrasound-guided injections and cryoablations between 2012 and 2018 was performed. Indications for therapeutic injection and cryoablation, were recorded. Studies were assessed for sonographic abnormalities related to the nerve and perineural soft tissues. Post-treatment outcomes including immediate pain scores, clinical follow-up, and periprocedural complications were documented. Results Twenty-four ultrasound-guided procedures were performed, including 15 perineural injections and nine cryoablations. With respect to sonographic abnormalities, nerve thickening (33%) and perineural hypoechoic scar tissue (27%) were the most common findings. The mean pain severity score prior to the therapeutic injection was 6.4/10 (range 4–10) and 0.25/10 (range 0–2) following the procedure; mean follow-up was 26.2 months (range 3–63 months). All of the cryoablation patients experienced sustained pain relief with a mean length follow-up of 3.75 months (range 0.2–10 months). Conclusion Therapeutic injection of Joplin's nerve is a safe and easily performed procedure under ultrasound guidance, with high rates of immediate symptom improvement. For those experiencing a relapse or recurrent symptoms, cryoablation offers an effective secondary potential treatment option.

Background The first dorsal metacarpal artery flap, including dorsal digital nerves with or without dorsal branches of the proper digital nerves, can be used to reconstruct thumb pulp defects with good results. However, it is still unclear whether there are differences in the sensory outcomes between preserving or not preserving the dorsal branches of the proper digital nerves. Methods This retrospective cohort study included 137 thumb pulp defect patients who underwent first dorsal metacarpal artery flap reconstruction procedure from October 2015 to June 2019. Patients were divided into two groups according to whether the dorsal branches of the proper digital nerves were preserved. In the non-preservation group (n = 80), the dorsal digital nerves were included in the flap for sensory reconstruction. In the preservation group (n = 57), the dorsal digital nerves and the dorsal branches of the proper digital nerves of the index finger were included in the flap. The stump of the proper digital nerves in the defect was coaptated to the donor nerves of the flap using the end-to-end fashion. At the last follow-up, static two-point discrimination, Semmes–Weinstein monofilament scores, pain, cold intolerance of the reconstructed finger, and patient satisfaction in both groups were compared. Results All patients were followed up for at least 17 months. No significant differences were found regarding pain of thumb pulp, static two-point discrimination, Semmes–Weinstein monofilament score, cold intolerance in the injured finger, and patient satisfaction. The non-preservation group presented slightly shorter operative times (p Conclusion There are no differences at 2 years in postoperative clinical outcomes when dorsal digital nerves are used to reconstruct flap sensation regardless of preservation of the dorsal branches of the proper digital nerves in the first dorsal metacarpal artery flap. Level of evidence: Level III, retrospective comparative study.

Selective pan fibroblast growth factor receptor (FGFR) inhibitors have been linked to severe onycholysis, the uncomfortable separation of the nail plate from the nail bed. Recommendations to assist with FGFR inhibitor onycholysis vary based on the severity. We hypothesized that the application of topical lidocaine to mimic a digital nerve block would be beneficial in addition to traditional supportive care interventions and subsequently report its immediate and continued efficacy for targeted therapy-induced onycholysis.

Abstract Percutaneous release of the A1 pulley has been introduced as a therapeutic approach for trigger fingers and is suggested as an effective and safe alternative, where conservative treatments fail. The aim of the current study was to determine if percutaneous release with a 15° stab knife can effectively result in acceptable efficacy and lower complication rate. Methods In the present study, the percutaneous release of the A1 pulley was evaluated by percutaneous release using a 15° stab knife in 20 fresh-frozen cadaver hands (10 cadavers). One hundred fingers were finally included in the present study. The success rate of A1 pulley release as well as the complications of this method including digital vascular injury, A2 pulley injury, and superficial flexor tendon injury was evaluated, and finally, the data were analyzed by the SPSS software. Results The results showed a success rate of 75% for A1 pulley release in four fingers, followed by eleven fingers (90%) and eighty-five fingers (100%). Therefore, the A1 pulley was found to be completely released in eighty-five fingers (100%). Overall, the mean of A1 pulley release for these fingers was determined as 97.9%, indicating that percutaneous trigger finger release can be an effective technique using a 15° stab knife. Furthermore, our findings revealed no significant difference in the amount of A1 pulley release in each of the fingers in the right and left hands. Additionally, 17 fingers developed superficial scrape in flexor tendons, while 83 fingers showed no flexor tendons injuries and no other injuries (i.e., vascular, digital nerve, and A2 pulley injuries). Conclusions Percutaneous release of the A1 pulley using a 15° stab knife was contributed to acceptable efficacy and a relatively good safety in the cadaveric model.

Digital nerve block is one of the multimodal analgesia methods used in finger trauma cases. According to some studies, dexamethasone needs further investigation before being used routinely. We therefore investigated dexamethasone's effect on the parameters of digital nerve block. In this double-blind clinical study, 60 patients were allocated to two groups: lidocaine alone and lidocaine + dexamethasone. Groups were compared for pain intensity, analgesia duration and demographic characteristics. Patients in the intervention group received 3 cc 2% lidocaine + 1 cc (equivalent to 4 mg) dexamethasone and patients in the control group received 3 cc lidocaine 2% + 1 cc normal saline. The two groups were comparable for age and gender. In the lidocaine + dexamethasone group, postoperative pain severity was significantly lower and the pain-free period was longer (P 0.05). Dexamethasone as an adjuvant in digital nerve block after trauma reduced the severity of postoperative pain and increased the pain-free period.

To repair a short nerve gap, autograft, allograft, autogenous, or synthetic conduits are selected, but a vascularized nerve autograft is preferred to obtain a reliable postoperative outcome in the case of an unfavorable wound bed. The purpose of this report is to describe and evaluate two cases of repair of a proper digital nerve and volar soft tissue defect with a vascularized dorsal sensory branch of an ulnar nerve flap. The cases of two men, 40 and 20 years old, who suffered index finger defects due to crush lacerations that required a flap and a nerve graft, are presented. A 4.0 cm × 2.0 cm and a 3.2 cm × 1.6 cm flap, which were nourished by the perforators from the ulnar proper digital artery of the little finger, were elevated from the ulnar side of fifth metacarpal bone head and transferred for coverage of the soft tissue defect. A 4.6-cm and a 3.0-cm vascularized nerve graft was interposed in the nerve gap. The patients' postoperative courses were uneventful, and both patients had no complaints related to the donor site. Static and moving two-point discrimination were 8 and 6 mm, respectively, at 6 months after surgery in the first case and 5 and 3 mm, respectively, at 9 months after surgery in the second case. This flap, which could be elevated in the same operative field with a nerve having similar diameter to that of the proper digital nerve, was useful for repair of a finger volar tissue defect.

A single-institution case series is reported and a review of the literature on the outcomes of digital nerve gap reconstruction with the NeuraGen type 1 collagen nerve conduit (Integra Life Sciences, Plainsboro New Jersey, USA) and the Avance Nerve Graft (Axogen Inc., Alachua, Florida, USA) is presented.Thirty-seven patients were included with a minimal follow-up of 12 months. Primary outcome was postoperative sensory recovery measured by static 2-point discrimination test or the Semmes-Weinstein monofilament test. Secondary outcome measurements were perioperative or postoperative complications. Final outcome data were stratified to grade results as excellent, good, or poor.The mean nerve gap length was 14 ± 4.9 mm for the collagen conduits versus 18.4 ± 9.3 for nerve allografts. After 12 months, outcomes were graded as excellent sensory recovery in 48% of the collagen conduit repairs and 39% of the nerve allografts (P = 0.608), good in 26% of the conduits and 55% of the allografts (P = 0.074), and poor in 26% of the conduits versus 6% of the allografts (P = 0.091). One neuroma and 1 infection were reported. Graft rejection or extrusion was not observed.Nerve conduits and processed nerve allografts offer convenient off-the-shelf options for digital nerve gap repair. Both techniques offer effective means of reconstructing a digital nerve gap2.5 cm at a minimum of 12 months of follow-up. Future prospective randomized large sample size studies comparing nerve conduits with allografts are needed to perform subgroup analyses and to define their exact role in digital nerve injuries.

Background: Distal digital nerve repairs can present unique challenges for hand surgeons due to their sensitive location and ongoing difficulty obtaining soft tissue coverage in this region. Although autografts and nerve conduits have been shown to be of benefit with nerve gaps, they can have morbidities associated with their use. Nerve allografts have become a viable option over the past decade as their use has increased and data are now showing similar outcomes, particularly in short gap segments. Flaps and skin grafts are traditional coverage options for full thickness wounds but can pose challenges with multiple digit involvement, depth of wound, and critical structures exposed. Methods: We present a case where nerve allograft was used for distal digital nerve repair. Due to the distal nature of the nerve repair in the index digit distal to the trifurcation, the distal end of the nerve graft was connected to multiple small nerve ends. Dermal substitute was placed to achieve distal coverage of the affected digits. Results: At 6-month follow-up, the patient demonstrated improved strength, normal sensation, and full return of digital function. Conclusion: Nerve allograft can be used in combination with dermal skin substitute to achieve normal sensation and return of digital function following distal digital nerve injuries.

Complex digital injuries involving soft-tissue loss and digital nerve defect continues to pose a reconstructive challenge. This study reports the repair of such neurocutaneous defect with the bipedicled nerve flap or the Littler flap and compares the results of the two techniques.A retrospective study was conducted in 59 patients who had a neurocutaneous defect in the single digit treated with the bipedicled nerve flap or the Littler flap from Jul 2008 to May 2016. The patients were divided into two groups based on which flap was chosen. At the final follow-up, the two groups were compared for static two-point discrimination and Semmes-Weinstein monofilament scores on both flap and pulp, and pain, cold intolerance and patient satisfaction of the reconstructed digit.Significant differences were found in static two-point discrimination, pain, cold intolerance, and patient satisfaction (p 0.05). In comparison with the bipedicled flap group, the Littler flap group presented better discriminatory sensation in the flap and pulp, but exhibited higher incidence of pain and cold intolerance in the reconstructed digit. In the donor digits, the bipedicled flap group achieved lower pain incidence. Finally, the bipedicled flap group attained a larger degree of satisfaction than the Littler flap group.When reconstructing a complex neurocutaneous defect in the digit, choosing the bipedicled nerve flap rather than the Littler flap attains lower incidence of pain and cold intolerance, and higher patient satisfaction. Our results suggest that repair of the transected digital nerves can reduce neuroma incidence.

Muscle in vein (MIV ) conduits have gradually been employed in the last 20 years as a valuable technique in bridging peripheral nerve gaps after nerve lesions who cannot undergo a direct tension-free coaptation. The advantages of this procedure comparing to the actual benchmark (autograft) is the sparing of the donor site, and the huge availability of both components (i.e. muscle and veins). Here we present a case serie of four MIV performed at our hospital from 2018 to 2019. The results we obtained in our experi-ence confirmed its effectiveness both in nerve regeneration (as sensibility recovery) and in neuropathic pain eradication. Our positive outcomes encourage its use in selected cases of residual nerve gaps up to 30 mm.

Objective To identify the most comfortable digital nerve block by comparing painfulness and efficiency of two commonly used digital nerve blocks: the volar subcutaneous nerve block and the traditional dorsal nerve block. Methods Patients, age ≥ 18 years, presenting with an injury of the finger requiring regional anaesthesia were included. Patients were blindly randomized in receiving the one-injection subcutaneous volar nerve block (intervention group) or the two-injection traditional dorsal digital nerve block (control group). Primary outcome measure was discomfort of the injection. Secondary outcome measures were extent of anaesthesia in different regions of the finger, complication rate and satisfaction of the clinician. Results In total, 409 patients were randomly allocated to the intervention group (N=209) or control group (N=200). Discomfort of the injection was not different between both anaesthetic techniques. The mean pain score (Numerical Rating Scale – NRS) of the intervention group was 4.57 (range 0 – 9, CI 4.27 – 4.87, SD 2.18). The mean pain scores of the control group were 4.63 for the first injection (range 0 - 10; CI 4.28 – 4.99, SD 2.36) and 4.51 for the second injection (range 0 – 10; CI 4.14 – 4.87, SD 2.44). The traditional dorsal digital nerve block was better in anesthetizing the dorsal side of the finger. The subcutaneous volar nerve block was better or equivalent in terms of extent of anaesthesia on the volar side of the finger. Conclusion In patients requiring digital anaesthesia in the Emergency Department, the anaesthetic technique affects both the discomfort of the injection and extent of anaesthesia. The traditional dorsal digital nerve block is preferred for dorsal injuries. The subcutaneous volar nerve block is preferred for volar injuries.

Microscopic anatomical study of the hand requires difficult or destructive dissection techniques for each anatomical structure. Synchrotron phase-contrast imaging (sPCI) allows us to study precisely, at a microscopic resolution and in a nondestructive approach, the soft tissues and bone structures within a single 3D image. Therefore, we aimed to assess the capacity of sPCI to study the arterial anatomy of the hand and digits in human cadavers for anatomical purposes. A non-injected hand from an embalmed body was imaged using sPCI at 21-µm pixel size. The vascularization and innervation of the hands were virtually reconstructed at 84-µm resolution, and the medial neurovascular bundle of the third digit at 21 µm. The thinner-most distal structures were observed and reported. The diameter and thickness of the vascular and neural structures were defined on 2D computed tomographic axial projections, and using a granulometry method coupled to the 3D reconstructions. The vascularization of the hand was visible from the radial and ulnar arteries to the distal digital transverse anastomoses. The thinnest structure observed was the anastomotic arterial network around the proper palmar digital nerve. The latter emerged from the proper palmar digital artery and vascularized the nerve around its whole length and circumference. The perineural arterioles individualizable at this resolution had a diameter of 66-309 µm. In conclusion, sPCI allows both the arterial and neural anatomy of the hand to be studied at the same time, as well as the anatomical interactions between both networks. It facilitates the study of structures that have different sizes, diameters, thickness, and histological origin with great precision, in a noninvasive way, and using a single technique.

Background: Injuries to digital nerves are common with trauma to the hand, often requiring surgery. Surgical management of these injuries can be performed using several techniques: direct repair (neurorrhaphy), autograft, allograft, and conduit repair. In light of increasing the availability and use of various digital nerve repair techniques, a new systematic review and meta-analysis was undertaken to comparatively review the available evidence to determine any differences in outcomes to better guide treatment in cases with digital nerve gaps. Methods: Current literature on sensory outcomes of various digital nerve repair techniques was reviewed using static 2-point discrimination (S2PD), moving 2-point discrimination (M2PD), Semmes-Weinstein monofilament testing (SWMF), and complication rates as outcomes of interest. After inclusion and exclusion criteria were applied, 15 articles were reviewed and 625 nerve repairs were analyzed. Results: The average gap length for allograft repair, autograft repair, and conduit repair was 15.4, 24.7, and 13.4 mm, respectively. For S2PD outcomes, autograft repair was statistically superior to all other forms of repair. Allograft trended higher than neurorrhaphy and conduit repair, but results were not statistically significant. For SWMF outcomes, autograft repair was statistically superior to conduit repair and neurorrhaphy; it was statistically comparable with allograft repair. Allograft performed statistically superior to conduit repair relative to M2PD. Conclusions: Based on the current updated meta-analysis using newer data and techniques, we found that all available techniques have reasonable outcomes. Yet when managing a digital nerve injury with a gap, thereby excluding direct neurorrhaphy, both autograft and allograft performed comparably and were superior to conduit repair.

Repair of severed nerves without autograft or allograft has included suture, suture with glue alone, suture with conduit and suture with glue augmentation to conduit, where use of conduit is considered for separation of the nerve ends from 5 mm to 3 cm. Repairs must not only serve acutely to provide apposition of nerve ends but must enable the healing of the nerve. Using biological conduit can place suture at the ends of the conduit while fibrin glue alone eliminates suture but with limited strength. The combination of conduit and glue offers the growth guidance of conduit with sufficient strength from the glue to maintain the nerve within the conduit. The role of fibrin glue in the integrity of the repair remains an open question, however. We sought to determine the factors in the strength of a glue-conduit-nerve construct and include consideration of standard suture repair. Fresh-frozen cadaveric digital nerves were repaired with suture alone, with glue alone or with suture and glue together and then loaded to failure. Previously tested specimens with conduit, suture and glue were considered for comparison. The suture alone (2.02 N) and suture with glue (2.24 N) were not statistically different from each other but were statistically stronger than glue alone (0.15 N). When compared to the earlier results of the strength of conduit with glue (0.65 N), these simple results show that the glue and conduit act together. The increased area over which the glue adheres to the nerve and conduit creates a composite structure stronger than either alone.

Morton's neuroma is a commonly encountered cause of forefoot pain, which may limit weight-bearing activities and footwear choices. Although the aetiology and pathomechanism of this condition is controversial, the histological endpoint is well established as benign perineural fibrosis of a common plantar digital nerve, typically within the third intermetatarsal space. The diagnosis of Morton's neuroma is mainly based on characteristic symptoms and clinical findings, but may be confirmed by ultrasonography. Although ultrasound is a highly accurate diagnostic tool for Morton's neuroma, it is subject to interoperator variability due to differences in technique and level of experience. In this paper, the authors review the anatomy of the common plantar digital nerves and surrounding structures in the forefoot, which are deemed relevant to the understanding of Morton's neuroma, especially from a sonographic point of view. Several theories of the pathomechanism of Morton's neuroma are briefly discussed. The main purpose of this article is to illustrate the ultrasound techniques for evaluating Morton's neuroma and performing ultrasound-guided corticosteroid injections.

Lipoma is a common benign soft tissue tumor which rarely occurs in the hand. Lipomas of the hand seldomly cause pain or other symptoms. However, in certain areas, the mass effect from the lipoma may cause clinical symptoms. It rarely involves the deep areas such as synovial membrane and muscle and, sometimes, pressure on the peripheral nerves can cause pain and neurological symptoms. The treatment is surgical resection with a low rate of recurrence. However, the rate of recurrence is high in deep and infiltrating lipomas which preclude complete resection. In this article, we report a case of a large palmar lipoma arising from the flexor tenosynovium of the hand causing digital nerve compression.

Background: A hypothenar perforator free flap, which is harvested from the palm, is suitable for reconstruction of a finger pulp skin defect, but this flap has rarely been reported, and most of these flaps in previous published reports were designed on the proximal zone of the hypothenar area. In the present report, hypothenar perforator free flaps on the distal zone, namely distal hypothenar perforator free flaps, including two sensate flaps, were used for four cases with pulp defects. Methods: Four distal hypothenar perforator free flaps were used for four patients with skin defects of the finger pulp, including one thumb, two index fingers, and one little finger. The average period from the injury to reconstruction was 30.3 days (range 21 to 47 days). The age of the patients ranged from 49 to 68 years, and the flap size ranged from 18 × 30 to 25 × 45 mm2. Two cutaneous branches of the ulnar palmar digital nerve of the little finger were harvested for the sensate flaps. At final follow-up, sensory restoration of the flap was measured using the Semmes-Weinstein monofilament test and the static two-point discrimination test. Results: All donor sites were closed directly, and all flaps survived totally. The average postoperative period was 12 months (range 5 to 15 months). The Semmes-Weinstein monofilament test was all blue (3.61, 3.22, 3.61) for the three flaps followed-up for more than 12 months, including two sensate flaps and one insensate flap. The surgical scars were inconspicuous, and there were no donor site complications. Conclusions: We consider that a distal hypothenar perforator free flap has a high degree of usability for a medium-sized defect such as the whole finger pulp. In the future, whether sensory nerve branches of this flap should be sutured will need to be clarified.

Background Median nerve (MN) variation in the carpal tunnel has been well documented by Lanz. Encountering rarely documented variants, that do not fit into existing classifications, increases the risk of iatrogenic injury. Methods The random occurrence of two unclassifiable anatomical variants of the MN in the carpal tunnel gives motivation to search the literature for similar and identical cases. Case reports This article presents two cases of very rare anatomical variants of high division of the MN. First case is a pure high branching of the 3rd space common digital nerve (CDN). The second case is a high division of the MN to a thicker lateral component and a thinner medial component. The lateral component of the MN gives off the palmar cutaneous branch (PCB), the thenar motor branch (TMB), the 1st and 2nd space CDN's and contributes medially with a branch to the 3rd space CDN. The medial component of the MN bifurcates distally into a medial and lateral branch. The lateral branch from the medial component of the MN distally unites with the medial branch of the lateral component of the MN to form the 3rd space CDN. The medial branch from the medial component of the MN has a major contribution to the 4th space CDN from the ulnar nerve. In both cases, the medial component of the MN has a transmuscular course through the flexor digitorum superficialis (FDS) muscle. Discussion Finding similar case reports from worldwide suggests the need to improve current classification of the MN variants in the carpal tunnel. Conclusions One cannot rely entirely on the existing anatomical classifications of the MN in the carpal tunnel. There is an underappreciated risk of iatrogenic injury, especially in endoscopic carpal tunnel release, and a chance of missing out on repair of important anatomical structures in trauma cases. There is a possibility of augmenting group 3 of Lanz's classification by adding subgroup “3D High division of the MN with the medial component having a transmuscular course through the FDS muscle”, stating the different distal branching patterns.

Retrograde flow digital artery flaps are a versatile single-stage option for the coverage of fingertip and dorsal digit defects. There are technical challenges associated with pedicle dissection and preparation. Techniques vary predominantly in the vessel utilized (either the proper digital artery or its branches) and the incorporation of the digital nerve or its branches in the pedicle with subsequent neurorrhaphy. Venous failure is more common. There is often mild but perceivable donor site morbidity. Evidence favors an innervated flap for better sensory recovery. Cold intolerance follows sacrifice of a digital artery.

Digital nerves are intrinsic to the sensory and motor function of the hand. These nerves represent the terminal ramifications of the ulnar, median, and radial nerves and are located distal to the carpal tunnel and Guyon canal. With magnetic resonance imaging, traumatic and nontraumatic abnormalities of the digital nerves can be shown with high contrast as well as high spatial resolution. Digital nerve abnormalities are most commonly posttraumatic in nature; however, infection, inflammatory, vascular malformations, and neoplasms can rarely occur. Magnetic resonance imaging is playing an increasing role in the assessment of peripheral nerve injury throughout the body, and in the hand, which can accurately identify the extent and character of digital nerve abnormalities before operative intervention.

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.

Using histological sections of 12 hands from 12 human fetuses at 20-34 weeks of gestation (150-290 mm) and 14 fingers (index and small) from seven donated cadavers of elderly individuals (aged 78-95 years), we compared the features of Vater-Pacinian corpuscles between these two stages of life. Corpuscles with thin, tightly packed lamellae appeared to undergo a change to thick, loosely packed lamellae at 23-32 weeks. The typical fetal corpuscle had two parts: (1) a rod-like proximal part (0.2-0.6 mm in length) extending along the proximodistal axis of the finger, and (2) a distal end (0.1 mm) after acute bending of the proximal part. Corpuscles were associated with palmar digital nerves in the fingers, but were also present along the dorsal nerves in the thumb. A flower bouquet- or tree-like arrangement including 5-10 corpuscles extended to the dermis of the skin along a perforating artery. Serial sections of the thumb and fifth finger revealed approximately 80-180 corpuscles in the distal phalangeal segment. In elderly individuals, the corpuscles were distributed along the palmar digital nerve, but (1) their density was much lower than in fetuses and (2) a bouquet- or tree-like arrangement was rarely seen. In the distal segment, there were fewer than 40 adult corpuscles, being 0.2-0.5 mm thick and 1.0-2.5 mm long. Wavy or coiled corpuscles were evident. Because of the considerable differences in the distribution and number of corpuscles between the fetus and adult, they appear to undergo considerable depletion with age, especially along thin, superficial nerve branches.

Processed nerve allografts (PNAs) have been demonstrated to have improved clinical results compared with hollow conduits for reconstruction of digital nerve gaps less than 25 mm; however, the use of PNAs for longer gaps warrants further clinical investigation. Long nerve gaps have been traditionally hard to study because of low incidence. The advent of the RANGER registry, a large, institutional review board-approved, active database for PNA (Avance Nerve Graft; AxoGen, Inc, Alachua, FL) has allowed evaluation of lower incidence subsets. The RANGER database was queried for digital nerve repairs of 25 mm or greater. Demographics, injury, treatment, and functional outcomes were recorded on standardized forms. Patients younger than 18 and those lacking quantitative follow-up data were excluded. Recovery was graded according to the Medical Research Council Classification for sensory function, with meaningful recovery defined as S3 or greater level. Fifty digital nerve injuries in 28 subjects were included. There were 22 male and 6 female subjects, and the mean age was 45. Three patients gave a previous history of diabetes, and there were 6 active smokers. The most commonly reported mechanisms of injury were saw injuries (n = 13), crushing injuries (n = 9), resection of neuroma (n = 9), amputation/avulsions (n = 8), sharp lacerations (n = 7), and blast/gunshots (n = 4). The average gap length was 35 ± 8 mm (range, 25-50 mm). Recovery to the S3 or greater level was reported in 86% of repairs. Static 2-point discrimination (s2PD) and Semmes-Weinstein monofilament (SWF) were the most common completed assessments. Mean s2PD in 24 repairs reporting 2PD data was 9 ± 4 mm. For the 38 repairs with SWF data, protective sensation was reported in 33 repairs, deep pressure in 2, and no recovery in 3. These data compared favorably with historical data for nerve autograft repairs, with reported levels of meaningful recovery of 60% to 88%. There were no reported adverse effects. Processed nerve allograft can be used to reconstruct long gap nerve defects in the hand with consistently high rates of meaningful recovery. Results for PNA repairs of digital nerve injuries with gaps longer than 25 mm compare favorably with historical reports for nerve autograft repair but without donor site morbidity.

The purpose of this study was to assess sensory and functional nerve recovery after digital nerve injury in patients with an end-to-end suture (S) or with implantation of a collagen conduit (C) to bridge a nerve gap. Fifteen S and 11 C with a follow-up of 6–36 months and 28 healthy control participants were enrolled. Methods of assessments were quantitative sensory testing, the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH), range of motion and the painDetect questionnaire. After both procedures, sensory profiles showed largely recovered function of C and Aδ fibres but severe loss of Aβ-fibre function leading to increased mechanical detection thresholds. There was only minimal allodynia. Severe pain was absent. Patients with conduits reported more functional impairment, especially in work performance, which correlated with the assessed loss of Aß-fibre function. Level of evidence: III

Background: 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. Methods: 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. Results: 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. Conclusions: 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.

Objective To establish a noninvasive method to measure the neuromagnetic fields of the median nerve at the carpal tunnel after electrical digital nerve stimulation and evaluate peripheral nerve function. Methods Using a vector-type biomagnetometer system with a superconducting quantum interference device, neuromagnetic fields at the carpal tunnel were recorded after electrical stimulation of the index or middle digital nerve in five healthy volunteers. A novel technique for removing stimulus-induced artifacts was applied, and current distributions were calculated using a spatial filter algorithm and superimposed on X-ray. Results A neuromagnetic field propagating from the palm to the carpal tunnel was observed in all participants. Current distributions estimated from the magnetic fields had five components: leading and trailing components parallel to the conduction pathway, outward current preceding the leading component, inward currents between the leading and trailing components, and outward current following the trailing component. The conduction velocity and peak latency of the inward current agreed well with those of sensory nerve action potentials. Conclusion Removing stimulus-induced artifacts enabled magnetoneurography to noninvasively visualize with high spatial resolution the electrophysiological neural activity from the palm to the carpal tunnel. Significance This is the first report of using magnetoneurography to visualize electrophysiological nerve activity at the palm and carpal tunnel.

Purpose The formation of a symptomatic neuroma after digital tip amputation presents a vexing problem. There is currently no procedure that completely and consistently prevents hypersensitive neuroma formation. This report presents the results of a technique designed to limit axon regeneration and mechanical irritation by neuroma excision, dorsal transposition, and coaptation with the corresponding digital nerve. Methods A retrospective chart review was conducted to assess the effectiveness of neuroma excision with dorsal transposition and epineurial coaptation for postamputation symptomatic digital neuromas. Neuromas were excised using a midlateral fish-mouth incision. Digital nerves were mobilized to the dorsum of the digital tip and coapted using 9-0 nylon epineurial suture. The procedure was modified to salvage viable fingernails or to avoid excessive tension. Mass et al’s criteria system was used to evaluate effectiveness. Results Twenty-four patients with painful neuromas of the radial and ulnar digital nerves after traumatic amputation were included. Thirty-two digits underwent dorsal coaptation. This procedure was associated with a result considered good or excellent in 28 of 32 digits. Twenty-seven of 32 digits registered no pain or stump anesthesia after dorsal coaptation. Twenty-five of 32 digits demonstrated no interference with activities of daily living. Twenty-one of 24 patients returned to work. Conclusions Neuroma excision with dorsal transposition and epineurial coaptation is an effective treatment for postamputation symptomatic digital neuroma. Type of study/level of evidence Therapeutic IV.

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.

Background Glomus tumors in the digital nerve are extremely rare. Multiple intraneural glomus tumors in different digital nerve fascicles have not been previously reported. Case presentation We report the case of a 54-year-old male with a 1-year history of progressive numbness of the middle finger with point tenderness at the level of the middle phalanx. Surgical incision revealed the presence of two glomus tumors within different fascicles of the ulnar digital nerve of the middle finger. One tumor was excised along with surrounding fascicle, the other was removed leaving the fascicle intact. Subsequently, the patient regained function of the finger and no tumors have recurred. Conclusions Patients and physicians should be aware of the properties of intraneural glomus tumors so that early diagnosis and treatment can be sought. Electronic supplementary material The online version of this article (10.1186/s12885-019-6098-y) contains supplementary material, which is available to authorized users.

The purpose of this study was to identify surface anatomy of digital nerves in relation to the pigmented border of digits. Three-hundred and sixty digital nerves in 36 preserved adult cadaveric hands were dissected under magnification. The digital nerves were constantly located anterior to the pigmented border. The median curvilinear distance along the skin from the pigmented border to the digital nerves of the index, middle, ring and little fingers was 1.4 mm. In the thumb, this distance was 2.4 and 3.7 mm on the radial and ulnar sides, respectively. The digital nerve was located 2.4 mm deep to the skin in all fingers. The median angle to the nerve from the skin at the pigmented border was 30°. These dimensions differed in the thumb compared with the rest of the fingers. We conclude that the pigmented border of digits is a reliable anatomical landmark to locate digital nerves.

Finger injuries are commonly attended to in the emergency department, and digital nerve block is a frequently performed procedure for such injuries. This study compared the efficacy levels of the subcutaneous method according to the different injection sites.This was a simulation study for medical students who rendered medical service at the emergency department. One group performed subcutaneous injection of lidocaine at the volar side of the metacarpophalangeal (MCP) joint, while another group injected at the volar side of the proximal interphalangeal (PIP) joint. The time to anesthesia was measured at 30-s intervals. Pain at the injection site was measured using the numeric rating scale (NRS), while the length from the fingertip to the injection site and the circumference of the injection site were measured.A total of 82 participants were included, with 41 under the MCP joint group and the rest under the PIP joint group. The mean length from the fingertip to the needling point was 3.62 ± 0.63 cm in the PIP joint group and 5.90 ± 0.65 cm in the MCP joint group, while the mean circumference of the needling point was 4.93 ± 0.51 and 5.61 ± 0.58 cm, and the mean time to anesthesia was 2.55 ± 1.11 and 3.79 ± 1.28 min (p-value 0.001), respectively. The median value of NRS was 4 in both groups (p-value = 0.921). Length was correlated with the time to anesthesia (p-value = 0.018).Injection into the PIP joint showed the same anesthetic effect as injection into the MCP joint, but this effect occurred faster in the former.

OBJECTIVES: This study was designed to introduce the feasibility of fingertip reconstruction by using a free medial flap of the second toe without vein anastomosis. METHODS: In total, 8 patients with fingertip injuries were treated successfully with this method. Patients who underwent reconstruction from September 2016 to October 2017 in our hospital with an artery-only free medial flap transfer of the second toe for fingertip injuries were included, and patients who underwent additional procedures that may impact the postoperative results and were followed up for less than 6 months were excluded. Clinical trial registration: ChiCTR19000021883. RESULTS: According to the Allen classification, five patients had Type 3 injuries, and three patients had Type 4 injuries. One arterial nerve and one digital nerve were repaired at the same time. No additional dissection was performed in either the donor or recipient site of the dorsal or volar vein. Postoperative venous congestion was monitored based on the color, temperature and the degree of tissue oxygen saturation. The flap size ranged from 1.20*1.0 cm2 to 1.80*1.0 cm2. The reconstruction time was 71.86 (SD 14.75) minutes. The two-point discrimination and the monofilament results were satisfying; cold intolerance did not appear in five patients, and the other three patients had cold intolerance with grades of 4, 12 and 26, which were considered satisfactory. Moreover, leech therapy, continuous bleeding and needle sutures were not utilized in any cases. CONCLUSIONS: Reconstruction with a small artery-only free medial flap transfer of the second toe led to satisfactory sensory and motor function in the selected patients with fingertip injuries.

We present 2 cases where the initial history and examination were similar to a Morton's/interdigital neuroma. In both cases, however, diagnostic ultrasound revealed symptomatic snapping of the proper digital nerve of the fifth toe. The anatomy of the proper digital nerve of the fifth toe may predispose it to a snapping phenomenon. Clinical awareness of this atypical cause of forefoot pain can help guide the diagnosis and treatment in those patients with persistent and refractory lateral forefoot pain and paresthesias.

Background Direct comparison of nerve autograft, conduit, and allograft outcomes in digital nerve injuries is limited. This study aims to compare the outcomes of nerve autografts, allografts, and conduits relative to primary repair (PR) through a systematic review. Methods A review of literature related to digital nerve gap repairs was conducted using PubMed/MEDLINE. Included articles were human clinical studies on digital nerve injuries repaired with nerve autograft, allograft, bovine collagen conduit, or PR. Patient characteristics, injury details, and complications were collected. Greater than 6-month outcomes included static 2-point discrimination, the British Medical Research Council Scale, or Semmes-Weinstein. Results Four autograft, 4 allograft, 5 conduit, and 7 PR publications were included. Allografts had the most repairs (100%) with static 2-point discrimination less than 15 mm, followed by autografts (88%), conduits (72%), and PR (63%). In British Medical Research Council Scale results, autografts (88%) and allografts (86%) were similar for patients with at least S3+ sensibility, compared to conduit (77%) and PR (39%). For Semmes-Weinstein, autografts demonstrated 93% normal sensation or diminished light touch, compared to allografts (71%), PR (70%), or conduits (46%). Conduits had the highest complication rate (10.9%), followed by autografts (5.7%), allografts (3.0%), and PRs (0.4%). Conclusions Although a randomized clinical trial would provide strongest evidence of superiority, this review presents the highest percentage of patients with normal to near normal sensory recovery in allograft and autograft repairs with low rates of complications. Nerve conduit studies reported a higher rate of incomplete recovery of sensation and complications.

Objectives Laser speckle contrast imaging (LSCI) has seen limited use in the study of perfusion dynamics such as vasomotion. The aim of this study was to investigate the effects of a prolonged seated position on perfusion dynamics in the nail bed using LSCI. Methods Perfusion was recorded in digits II to IV bilaterally for 20 min during two separate sessions in ten healthy volunteers. The acclimatization period was 5 min for the 1st session and 20 min for the 2nd. Perfusion variability and the presence of recurring perfusion dips were analyzed. A digital nerve block was done to verify suspected nervous origin of phenomenon. Results Synchronized phases of vasoconstriction were observed in all subjects with perfusion dips in all digits bilaterally and simultaneously. Application of a digital nerve block abolished perfusion dips. The frequency of this phenomenon increased by 25.0% (95% CI: 1.6 to 49.2%) in the left-hand digits after a prolonged seated position. Perfusion variability increased by 11.6% (95% CI: 2.6 to 20.3%) in the digits of the left hand. Perfusion changes in right-hand digits did not significantly increase. During the 1st session, temperature increased by 2.7 °C (1.1 to 4.2) while it decreased by 1.3 °C (0.2 to 2.4) during the 2nd session. Conclusion The observed perfusion dips are of a centrally mediated nervous origin but are also affected by local factors. They are affected by seating duration and differ between left and right hands, likely because of local micro perfusion dips. This phenomenon seems related to digital thermoregulation.

To determine whether ultrasound allows precise assessment of the course and relations of the medial plantar proper digital nerve (MPPDN). This work was initially undertaken in six cadaveric specimens and followed by a high-resolution ultrasound study in 17 healthy adult volunteers (34 nerves) by two musculoskeletal radiologists in consensus. Location and course of the MPPDN and its relationship to adjacent anatomical structures were analysed. The MPPDN was consistently identified by ultrasound along its entire course. Mean cross-sectional area of the nerve was 0.8 mm2 (range 0.4–1.4). The MPPDN after it branches from the medial plantar nerve was located a mean of 22 mm (range 19–27) lateral to the medial border of the medial cuneiform. More distally, at the level of the first metatarsophalangeal joint, mean direct distances between the nerve and the first metatarsal head and the medial hallux sesamoid were respectively 3 mm (range 1–8) and 4 mm (range 2–9). The MPPDN can be depicted by ultrasonography. Useful bony landmarks for its detection could be defined. Precise mapping of its anatomical course may have important clinical applications. • The medial plantar proper digital nerve (MPPDN) rises from the medial plantar nerve to the medial side of the hallux. • Because of its particularly long course and superficial position, the MPPDN may be subject to trauma, resulting in a condition known as Joplin’s neuroma. • The MPPDN can be clearly depicted by ultrasound along its entire course. Precise mapping of its anatomical course may have important clinical applications.

Joplin's neuroma is a rare perineurial fibrosis of the medial plantar digital proper nerve arising from various etiologies but most commonly after bunion surgery. Treatment for this painful great toe problem remains controversial. It is our purpose to describe our experience with this chronic pain problem, considering it to be a neuroma requiring resection. A retrospective medical record review of 8 patients with medial hallux pain related to the digital nerve was performed. Each patient had failed to respond to >6 months of nonoperative therapy. At surgery, the medial digital nerve to the hallux was identified distally, the neuroma was resected distally, and the proximal end of the nerve was implanted into the arch of the foot in 7 (87.5%) of the 8 patients. At a mean follow-up of 25 (range 13 to 43) months, 6 results (75%) were excellent, 1 (12.5%) was good, and 1 (12.5%) was fair. The 1 fair result was in the only patient in whom the distal end of the divided nerve was not implanted proximally, according to the patient's request. In conclusion, surgical resection of the medial plantar nerve to the hallux with implantation of the proximal end of the nerve into the arch of the foot, can be expected to result in good to excellent relief of pain in 80% of the patients.

Background Digital nerve blocks are commonly performed in emergency departments. Health care practitioners are often taught to avoid performing blocks with epinephrine due to a risk of digital necrosis. Objective To review the literature on the safety of epinephrine 1:100,000–200,000 (5–10 μg/mL) with local anesthetics in digital nerve blocks in healthy patients and in patients with risk for poor peripheral circulation. Methods PubMed, Web of Science, and the Cochrane Library were searched in June 2014 using the query “digital block AND epinephrine OR digital block AND adrenaline”. The searches were performed without any limits. Results Sixty-three articles were identified, and 39 of these were found to be relevant. These include nine reviews, 12 randomized control trials, and 18 other articles. Most studies excluded patients with risk for poor peripheral circulation. Two studies described using epinephrine on patients with vascular comorbidities. No study reported digital necrosis or gangrene attributable to epinephrine, either in healthy patients or in patients with risk for poor peripheral circulation. In total, at least 2797 digital nerve blocks with epinephrine have been performed without any complications. Conclusions Epinephrine 1:100,000–200,000 (5–10 μg/mL) is safe to use in digital nerve blocks in healthy patients. Physiological studies show epinephrine-induced vasoconstriction to be transient. There are no reported cases of epinephrine-induced harm to patients with risk for poor peripheral circulation despite a theoretical risk of harmful epinephrine-induced vasoconstriction. A lack of reported complications suggests that the risk of epinephrine-induced vasoconstriction to digits may be overstated.

Purpose We report the efficacy of a modified heterodigital neurovascular island flap innervated by the dorsal branch of the proper digital nerve and the proper digital nerve, for repairing either pulp or volar defects in the fingers. Method We repaired 14 digits of 14 patients who had a complex defect involving soft tissue and digital nerve in the pulp or volar surface of the digit using the modified heterodigital neurovascular island flap. Cases were divided into 2 groups: a pulp defect group including 5 thumbs and 1 little finger; and a volar defect group with a digital nerve defect, involving one thumb, 3 index and 3 middle fingers, and one ring finger. At the recipient site, nerve stumps of the PDNs in the pulp defect group were coapted with the proximal ends of the dorsal branch of the PDN and the proper digital nerve in the flap. The distal and proximal ends of the PDN in the flap were intercalated into the defect of the PDN in volar defect group, and the proximal end of dorsal branch of PDN in the flap was also coapted to the proximal end of the proper digital nerve of the recipient finger. At the donor site, the defect of the proper digital nerve was repaired with nerve graft harvested from the proximal portion of the dorsal branch of the same proper digital nerve, and a full-thickness skin graft covered the donor site. Results All flaps and the skin grafts of the donor site survived completely. At the final follow-up, 9 of 14 flaps had a static 2-point discrimination result below the normal threshold ( Conclusions The modified heterodigital neurovascular island flap is a useful and reliable treatment option for a digital pulp or volar defect, especially when the digital nerve defect requires repair. Type of study/level of evidence Therapeutic IV.

Malignant granular cell tumors are an extremely rare, high-grade sarcoma with a schwannian phenotype and are composed of malignant granular cells with cytoplasmic lysosomal inclusion. To date, 157 cases of malignant granular cell tumors have been reported. We report the first case of a malignant granular cell tumor arising from the digital nerve to the median nerve in the palm, and we review the 157 previously reported cases and summarize the clinical profile, treatment, and outcome of this tumor. The median age, tumor size, and follow-up periods were 51 years, 6 cm, and 24 months respectively. With respect to the oncological result, 53 patients (33.8%) had no evidence for disease, 31 (19.7%) were alive with the disease, and 51 (32.5%) died because of the disease. Our case report indicates that rare malignant tumors can arise from the digital nerve to the median nerve in the palm, an anatomical site that is usually affected by benign lesions. Exhaustive discussions between surgeons and pathologists are necessary for the treatment of this rare malignant tumor.