Revision Decompression and Collagen Nerve Wrap for Recurrent and Persistent Compression Neuropathies of the Upper Extremity

A functional tacrolimus-releasing nerve wrap for enhancing nerve regeneration following surgical nerve repair

JOURNAL/nrgr/04.03/01300535-202501000-00036/figure1/v/2024-05-14T021156Z/r/image-tiff Axonal regeneration following surgical nerve repair is slow and often incomplete, resulting in poor functional recovery which sometimes contributes to lifelong disability. Currently, there are no FDA-approved therapies available to promote nerve regeneration. Tacrolimus accelerates axonal regeneration, but systemic side effects presently outweigh its potential benefits for peripheral nerve surgery. The authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site, with suitable properties for scalable production and clinical application, aiming to promote nerve regeneration and functional recovery with minimal systemic drug exposure. Tacrolimus is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 days. Size and drug loading are adjustable for applications in small and large caliber nerves, and the wrap degrades within 120 days into biocompatible byproducts. Tacrolimus released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80% compared with systemic delivery. Given its surgical suitability and preclinical efficacy and safety, this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.

Muscular branches from the ulnar artery are the basis for a pedicled partial flexor digitorum superficialis muscle flap

The feasibility of a pedicled flexor digitorum superficialis muscle flap was studied in 10 fresh cadavers. The number, length and distance from the flexion wrist crease of muscular branches from the ulnar artery in the distal 10 cm of the forearm were recorded. The mean number of muscular branches was 2.7 (range 1-4). The mean distance of the most distal branch was 35 mm (range 26-40) from the proximal wrist flexion crease. Its mean length was 20 mm (range 16-26). A partial muscle flap was raised on the most distal branch and transposed over the median nerve in the distal forearm. Dissection and transposition of this flap were feasible in all specimens. The reliable pattern of muscular branches to the flexor digitorum superficialis allows the elevation of a pedicled partial muscle flap that can cover the median nerve in the distal forearm.Level of evidence: V.

Efficacy of collagen conduit wrapping with collagen fibers on nerve regeneration in sciatic nerve injury with partial transection: An experimental study in the rat model

Peripheral nerve injuries (PNIs) include complete and partial transection, crushing, and chronic compression injuries. Hollow absorbable conduits are used to treat complete transection with short defects, while wrapping the injured part with an absorbent material promotes nerve recovery by inhibiting inflammatory cell infiltration and scar tissue formation in crush injuries. For treatment of partially transected nerve injuries (PTNIs), such as injection-related iatrogenic PNI, whether wrapping the entire nerve, including the injury site, or bridging the transected fascicle with an artificial nerve conduit (ANC) is beneficial remains to be verified. The purpose of this study was to investigate whether wrapping the injured nerve and placing collagen fibers as scaffolds at the nerve defect site contribute to neural recovery in PTNI. A unilateral 5-mm partial nerve defect was created at the mid-thigh level in a rat sciatic nerve injury model. Fifty-four Sprague-Dawley (SD) rats (150-250 g) were divided into three groups (n = 9 each): group 1, collagen fibers were placed in the nerve defect and the sciatic nerve was wrapped with collagen conduit; group 2, the sciatic nerve was wrapped by collagen conduit without collagen fibers; and group 3, nerve defect was reconstructed with collagen-filled conduit. Nerve regeneration was evaluated by analyses of gait, electrophysiology, wet muscle weight, and axon numbers with immunohistochemistry at 12 and 24 weeks. Dorsiflexion angles among all groups improved significantly from 12 to 24 weeks postoperatively. At 24 weeks postoperatively, compound muscle action potential amplitudes (CMAPs) of tibialis anterior were 5.26 ± 4.64, 1.31 ± 1.17, and 0.14 ± 0.24 mV (p < .05), CMAPs of gastrocnemius were 21.3 ± 5.98, 15.4 ± 5.46, and 13.11 ± 3.91 mV in groups 1, 2, and 3, respectively; and the value of group 1 was significantly higher than that of group 3 (p < .05). Axon numbers were 2194 ± 629; 1106 ± 645; and 805 ± 907 in groups 1, 2, and 3, respectively (p < .05). For PTNI reconstruction, artificial nerve wrap (ANW) was superior to ANC. Providing collagen scaffold at the nerve defect site enhanced nerve recovery during reconstruction with ANW.

Comparison of in-situ release and submuscular anterior transposition of ulnar nerve for refractory cubital tunnel syndrome, previously treated with subfascial anterior transfer-A retrospective study of 24 cases

BACKGROUND

Although cubital tunnel syndrome is the second most common type of compressive neuropathy in the upper extremities, the indication and optimal surgical method for recurrent or refractory cubital tunnel syndrome remains controversial. This study evaluates the functional outcomes of revision surgery for cubital tunnel syndrome.

MATERIAL & METHODS

This study was a retrospective observational multicenter single-institution study including 660 patients who underwent surgery for cubital tunnel syndrome from 2010 to 2019. Among the 660 patients, 42(6.4%) received revision surgery due to remaining or recurrent symptoms confirmed with electromyography(EMG). After excluding those with concurrent elbow fracture, dislocation, osteoarthritis and wound infection, a total of 24 patients were included in the study. The patients were evaluated of disease severity, revision surgical method, time interval to recurrence, underlying diseases and postoperative functional outcomes.

RESULTS

All patients received ulnar nerve subfascial anterior transposition for the initial cubital tunnel syndrome surgery. Among the 24 patients (3.7%) who received revision surgery, nine received in situ neurolysis, 12 received submuscular transposition, and three received subcutaneous transfer. 21 patients (88%) reported improved mean VAS score of 4.3, while three patients complained of remaining symptoms that did not improve even after revision surgery. The patients with remaining symptoms all had underlying diabetes mellitus and were treated with subcutaneous transfer. The difference of surgical outcomes between the in situ neurolysis group and the nerve transfer groups were non-significant (p = 0.23). The most common cause of recurrent or persistent symptoms was adhesion and fibrosis at sling area. The mean follow up period before revision surgery was 26.3 months and postoperative follow up period after revision surgery was 8.5 months.

CONCLUSION

The outcomes of this study imply that in-situ neurolysis may be as effective as anterior submuscular transfer of ulnar nerve for refractory cubital tunnel syndrome after anterior subfascial transfer.

Shielding the Nerve: A Systematic Review of Nerve Wrapping to Prevent Adhesions in the Rat Sciatic Nerve Model

BACKGROUND

Peripheral nerve pathology is frequently encountered in clinical practice among peripheral nerve and extremity surgeons. One major factor limiting nerve regeneration and possibly leading to revision surgeries is the development of traumatic or postoperative adhesions and scarring around nerves. In experimental models, different materials have been studied to limit scar tissue formation when wrapped around nerves.

METHODS

A systematic review of studies describing nerve-wrapping materials in a non-transectional rat sciatic nerve model was performed following the PRISMA guidelines. Literature describing nerve-wrapping methods for the prevention of peripheral nerve scarring in rat sciatic nerve models was identified using PubMed and Web of Science, scanned for relevance and analyzed.

RESULTS

A total of 15 original articles describing 23 different materials or material combinations for nerve wrapping were included. The heterogeneity of the methods used did not allow a meta-analysis, thus, a systematic review was performed. Out of 28 intervention groups, 21 demonstrated a preventive effect on scar tissue formation in at least one qualitative or quantitative assessment method.

CONCLUSIONS

The analyzed literature describes a variety of materials from different origins to limit peripheral nerve scarring and adhesions. Thus, a scar-preventive effect by wrapping peripheral nerves as adhesion prophylaxis seems likely. However, a quantitative comparison of the studies to identify the optimal material or technique is not possible with the diversity of used models and study designs. Therefore, further research needs to be performed to identify the optimal nerve wraps to be used routinely in clinical practice.

Advancing Nerve Regeneration: Translational Perspectives of Tacrolimus (FK506)

Peripheral nerve injuries have far-reaching implications for individuals and society, leading to functional impairments, prolonged rehabilitation, and substantial socioeconomic burdens. Tacrolimus, a potent immunosuppressive drug known for its neuroregenerative properties, has emerged in experimental studies as a promising candidate to accelerate nerve fiber regeneration. This review investigates the therapeutic potential of tacrolimus by exploring the postulated mechanisms of action in relation to biological barriers to nerve injury recovery. By mapping both the preclinical and clinical evidence, the benefits and drawbacks of systemic tacrolimus administration and novel delivery systems for localized tacrolimus delivery after nerve injury are elucidated. Through synthesizing the current evidence, identifying practical barriers for clinical translation, and discussing potential strategies to overcome the translational gap, this review provides insights into the translational perspectives of tacrolimus as an adjunct therapy for nerve regeneration.

Compression Neuropathies: Revisions and Managing Expectations

Most compression neuropathies can be reliably treated with surgical decompression; however, in approximately 25% of the cases, this release fails, requiring revision surgery. Defining the correct diagnosis after a failed nerve decompression (ie, persistent, recurrent, or new symptoms) is of the utmost importance and guides toward the optimal treatment. This article describes the clinical categorization of secondary carpal tunnel syndrome and cubital tunnel syndrome, intraoperative principles of revision surgery and treatment options that are currently available.

Management of Failed Carpal and Cubital Tunnel Release: An Evidence-Based Guide to Success

Carpal tunnel and cubital tunnel syndromes are the most common compressive neuropathies of the upper extremity with surgical treatment having high success rates for both conditions. Although uncommon, persistent or recurrent carpal and cubital tunnel syndrome presents a challenge for patients and providers. Diagnosis of persistence versus recurrence of the pathology is key in establishing an appropriate treatment plan to provide the best possible patient outcomes. After an established diagnosis, a wide array of treatment options exist which varies based on previous procedures performed. This review discusses relevant anatomy, etiology, and clinical presentations of persistent and recurrent carpal and cubital tunnel syndromes. The range of treatment options is presented based on history and diagnostic findings. Treatment options span from revision of nerve decompression to the use of soft tissue rearrangement procedures. Some specific treatment options discussed include simple revision nerve decompression, external neurolysis, soft tissue rearrangement, such as the hypothenar fat flap or various transposition techniques, and the use of nerve wraps. Included is an evidence-based management guide for diagnosis and treatment of persistent versus recurrent carpal and cubital tunnel syndromes.

Modern Treatment of Cubital Tunnel Syndrome: Evidence and Controversy

Cubital tunnel syndrome is the second most common peripheral mononeuropathy in the upper extremity. However, the diagnosis and treatment of cubital tunnel syndrome remains controversial without a standard algorithm. Although diagnosis can often be made from the patient's history and physical examination alone, electrodiagnostic studies, ultrasound, computed tomography (CT), and magnetic resonance image (MRI) can also be useful in diagnosing the disease and selecting the most appropriate treatment option. Treatment options include conservative nonoperative techniques as well as various surgical options, including in situ decompression with or without transposition, medial epicondylectomy, and nerve transfer in advanced disease. The purpose of this review is to summarize the most up-to-date literature regarding cubital tunnel syndrome and propose a treatment algorithm to provide clarity about the challenges of treating this complex patient population.

Avive Soft Tissue Membrane Improves Outcomes of Revision Upper-extremity Nerve Decompression Surgery

Revision nerve decompression remains a challenge for surgeons. Avive Soft Tissue Membrane is processed human umbilical cord membrane that may reduce inflammation and scarring, thereby improving tissue gliding. Although synthetic conduits have been reported in revision nerve decompression, the use of Avive has not.

Methods

Prospective study of revision nerve decompression with Avive application. VAS pain, two-point discrimination, Semmes-Weinstein, pinch and grip strength, range of motion, Quick Disability of Arm, Shoulder & Hand (QuickDASH), and satisfaction were recorded. Using a propensity-matched cohort, VAS pain and satisfaction were retrospectively collected to compare with cohort outcomes.

Results

In the Avive cohort, 77 patients (97 nerves) were included. Mean follow-up was 9.0 months. Avive was applied to the median nerve in 47.4%, ulnar nerve in 39.2%, and radial nerve in 13.4%. VAS pain was 4.5 preoperatively and 1.3 postoperatively. S4 sensory recovery was achieved in 58% of patients, S3+ in 33%, S3 in 7%, S0 in 2%, and improvement from baseline in 87%. Strength improved in 92%. Mean total active motion was 94.8%. Mean QuickDASH score was 36.1, and 96% reported improved or resolved symptoms. Preoperative pain was not significantly different between Avive cohort and controls (P = 0.618). Postoperative pain was significantly lower in cohort patients (1.3 ± 2.2 versus 2.7 ± 3.0, P = 0.001). In the Avive cohort, more had improved or resolved symptoms (P < 0.0001). Clinically important improvement in pain was reported in 64.9% of Avive group patients versus 40.8% of controls (P = 0.002).

Conclusion

Avive contributes to improved outcomes in revision nerve decompression.

Recalcitrant Neuropathies in the Upper Extremity

Carpal and cubital tunnel syndrome can cause debilitating pain and weakness in the hand and upper extremities. Although most patients have a resolution of their symptoms after primary decompression, managing those with recalcitrant neuropathies is challenging. The etiology of persistent, recurrent, or new symptoms is not always clear and requires careful attention to the history and physical examination to confirm the diagnosis or consider other causes prior to committing to surgery. Nevertheless, revision surgery is often needed in the setting of recalcitrant neuropathies in order to improve patients' symptoms. Revision surgery typically entails wide exposure and neurolysis to release residual compression. In addition, vascularized tissue and nerve wraps have been routinely used to create a favorable perineural environment that decreases recurrent scar formation. This review discusses the etiologies of recalcitrant upper extremity neuropathies, the current treatment options, and surgical outcomes.

Outcomes following use of VersaWrap nerve protector in treatment of patients with recurrent compressive neuropathies

Epineural scarring following previous carpal or cubital tunnel release can lead to pain and permanent dysfunction. To prevent this cascade, nerve wraps are an option. The purpose of this study was to evaluate outcomes following use of VersaWrap nerve protector during surgical decompression and neurolysis in patients with recurrent compressive neuropathies in the upper extremity. Twenty patients comprised the patient cohort, with a mean postoperative follow-up time of 139 days (range: 42-356 days). There were 13 females and 7 males, with a mean age of 43.4 years. Fourteen surgeries were performed for revision cubital tunnel, 5 for revision carpal tunnel, and 1 for revision radial tunnel syndrome. Average duration of symptoms prior to revision surgery with VersaWrap was 2 years (range 9 months to 6 years). Postoperatively, the mean DASH score was 57.7 and VAS 3.1. Mean s2PD median distribution was 7.3, s2PD ulnar distribution 8.9, m2PD median distribution 6.9 and m2PD ulnar distribution 7.3. All patients had subjective improvement of symptoms and were satisfied with their result. No patients in our cohort required further revisional surgery. In conclusion, the use of VersaWrap as a nerve protector following revision surgery for recurrent compressive neuropathies in the upper extremity was safe and effective. Level of Evidence: IV; retrospective case series.

Understanding carpal tunnel syndrome

ABSTRACT

Carpal tunnel syndrome (CTS) is an entrapment neuropathy affecting the median nerve. Prevalence is estimated at 4% to 5% of the population. A solid understanding of the anatomy, presentation, and diagnostics is key to efficient diagnosis and appropriate referral. Both surgical and nonsurgical interventions have led to improved clinical outcomes. Clinicians who have an in-depth knowledge of CTS symptoms and treatment options can prepare patients and streamline referrals for improved patient outcomes.

Clinical outcomes following neurolysis and porcine collagen extracellular matrix wrapping of scarred nerves in revision carpal tunnel decompression

Scar tether after primary nerve decompression can impair physiological nerve glide and vascularity of the nerve. Revision decompression in the setting of neurostenalgia should address the scarred mesoneurium in order to prevent further entrapment and tether. This study reports on the clinical outcomes of 12 patients with neurostenalgia following carpal tunnel decompression (CTD), treated with revision CTD and a porcine submucosa extracellular matrix nerve wrap (PECM) (Axoguard® nerve protector, Axogen Inc., Alachua, FL). Eleven patients had one primary decompression procedure prior to revision surgery; one patient previously had two operations for CTD. There was a significant reduction in visual analogue pain scores (VAS) and improvement in patients' satisfaction rating and symptom resolution. Patient-reported outcome measures were recorded using the Impact of Hand Nerve Disorders (I-HaND) Scale (Version 2), which demonstrated a significant reduction in hand disability. There were no complications attributable to the procedure and no re-revision procedures necessary at the latest follow-up.

Necrotic Granulomatous Inflammation after Use of Small Intestine Submucosa Matrix for Recurrent Compression Neuropathy

Various techniques exist for treating recurrent carpal and ulnar tunnel syndrome, but AxoGuard nerve wrap has shown promising results for treatment of compression neuropathies when used in conjunction with neurolysis and tenosynovectomy. Prior results demonstrate no safety concerns, and there have not been any reported cases of infection, persistent inflammation, or recurrent perineural fibrosis. A 41-year-old, right-hand-dominant woman experienced repeated bouts of carpal and ulnar tunnel syndromes, which were treated with a small intestine submucosa matrix wrap around the median and ulnar nerves in the wrist. Here, we report a case of necrotic granulomatous inflammation 2.5 months after AxoGuard xenograft nerve wrap was placed around the median and ulnar nerves. As a salvage, NuShield placental allograft was wrapped around the median nerve, which has shown promising results at several months follow-up. Placental allograft nerve wraps represent a useful tool in compression neuropathy resistant to autografts, xenografts, and revision decompression operations.

An Update on Posterior Tarsal Tunnel Syndrome

Posterior tarsal tunnel syndrome (PTTS) is an entrapment neuropathy due to compression of the tibial nerve or one of its terminal branches within the tarsal tunnel in the medial ankle. The tarsal tunnel is formed by the flexor retinaculum, while the floor is composed of the distal tibia, talus, and calcaneal bones. The tarsal tunnel contains a number of significant structures, including the tendons of 3 muscles as well as the posterior tibial artery, vein, and nerve. Focal compressive neuropathy of PTTS can originate from anything that physically restricts the volume of the tarsal tunnel. The variety of etiologies includes distinct movements of the foot, trauma, vascular disorders, soft tissue inflammation, diabetes mellitus, compression lesions, bony lesions, masses, lower extremity edema, and postoperative injury. Generally, compression of the posterior tibial nerve results in clinical findings consisting of numbness, burning, and painful paresthesia in the heel, medial ankle, and plantar surface of the foot. Diagnosis of PTTS can be made with the presence of a positive Tinel sign in combination with the physical symptoms of pain and numbness along the plantar and medial surfaces of the foot. Initially, patients are treated conservatively unless there are signs of muscle atrophy or motor nerve involvement. Conservative treatment includes activity modification, heat, cryotherapy, non-steroidal anti-inflammatory drugs, corticosteroid injections, opioids, GABA analog medications, tricyclic antidepressants, vitamin B-complex supplements, physical therapy, and custom orthotics. If PTTS is recalcitrant to conservative treatment, standard open surgical decompression of the flexor retinaculum is indicated. In recent years, a number of alternative minimally invasive treatment options have been investigated, but these studies have small sample sizes or were conducted on cadaveric models.

Management of Recurrent Carpal Tunnel Syndrome: Systematic Review and Meta-Analysis

PURPOSE

Few comparisons have been performed between the outcomes of surgical techniques for recurrent carpal tunnel syndrome. Using a meta-analysis, this study aimed to compare the outcomes of different surgical techniques using the Boston Carpal Tunnel Questionnaire (BCTQ) and visual analog scale (VAS) for pain as outcomes.

METHODS

The following categories were used to define the study's inclusion criteria: population, intervention, comparator, outcomes, and study design. Studies were examined by 2 reviewers, and the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines were followed. The studies were assigned to 1 of the following treatment groups: decompression with or without neurolysis, autologous fat transfer, hypothenar fat pad, pedicled or free flap, and "other." For our primary outcome, we compared improvement using the BCTQ and VAS for pain between the treatment groups. For our secondary outcome, postoperative BCTQ and VAS pain values were compared.

RESULTS

Fourteen studies were included: 5 case series with postoperative data only and 9 pre-post studies without a control group. With regard to our primary outcome, the studies reported an average improvement of 1.2 points (95% confidence interval [CI][1.5, 0.9]) on a scale of 1-5 on the symptoms severity scale (SSS) of the BCTQ, 1.9 points (95% CI [1.37, 0.79]) on a scale of 1-5 on the function severity scale of the BCTQ, and 3.8 points (95% CI [4.9, 2.6]) on a scale of 1-10 on the VAS for pain. We only found significantly lesser improvement in the "other" treatment group than in the hypothenar fat pad group and autologous fat transfer group using the SSS. The hypothenar fat pad group had the best reported postoperative SSS score of 1.75 (95% CI [1.24, 2.25]), function severity scale score of 1.55 (95% CI [1.20, 1.90]), and VAS pain score of 1.45 (95% CI [0.83, 2.07]).

CONCLUSIONS

All the techniques showed clinically important improvements in all the outcomes. We found lesser improvement in the "other" treatment group than in the hypothenar fat pad group and autologous fat transfer group using the SSS. We found that the hypothenar fat pad group had the best reported postoperative values in our secondary analysis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Revision of Carpal Tunnel Surgery

Carpal tunnel release is one of the most commonly performed upper extremity procedures. The majority of patients experience significant improvement or resolution of their symptoms. However, a small but important subset of patients will experience the failure of their initial surgery. These patients can be grouped into persistent, recurrent, and new symptom categories. The approach to these patients starts with a thorough clinical examination and is supplemented with electrodiagnostic studies. The step-wise surgical management of revision carpal tunnel surgery consists of the proximal exploration of the median nerve, Guyon’s release with neurolysis, the rerelease of the transverse retinaculum, evaluation of the nerve injury, treatment of secondary sites of compression, and potential ancillary procedures. The approach and management of failed carpal tunnel release are reviewed in this article.

Effect of Collagen Nerve Wrapping in a Rabbit Peripheral Neuropathy Model

Background:

Collagen nerve wraps (CNWs) theoretically allow for improved nerve gliding and decreased perineural scarring, and create a secluded environment to allow for nerve myelination and axonal healing. The goal of this study was to investigate the effect of CNWs on nerve gliding as assessed by pull-out strength and nerve changes in a rabbit model of peripheral neuropathy.

Methods:

Ten New Zealand rabbits were included. Sham surgery (control) was performed on left hindlimbs. To simulate compressive neuropathy, right sciatic nerves were freed of the mesoneurium, and the epineurium was sutured to the wound bed. Five rabbits were euthanized at 6 weeks [scarred nerve (SN); n = 5]. Neurolysis with CNW was performed in the remaining rabbits at 6 weeks (CNW; n = 5), which were euthanized at 22 weeks. Outcomes included peak pull-out force and histopathological markers of nerve recovery (axonal and Schwann cell counts).

Results:

The CNW group demonstrated significantly higher pull-out forces compared with the CNW sham control group (median: 4.40N versus 0.37N, P = 0.043) and a trend toward greater peak pull-out forces compared with the SN group (median: 4.40N versus 2.01N, P = 0.076). The CNW group had a significantly higher median Schwann cell density compared with the CNW control group (CNW: 1.30 × 10⁻³ cells/μm² versus CNW control: 7.781 × 10⁻⁴ cells/μm², P = 0.0431) and SN group (CNW: 1.30 × 10⁻³ cells/μm² versus SN: 7.31 × 10⁻⁴ cells/μm², P = 0.009). No significant difference in axonal density was observed between groups.

Conclusion:

Our findings suggest using a CNW does not improve nerve gliding, but may instead play a role in recruiting and/or supporting Schwann cells and their proliferation.

Flexor tenosynovectomy in carpal tunnel syndrome as a screening tool for early diagnosis of amyloidosis

INTRODUCTION

Amyloidosis is a heterogeneous group of diseases that most often presents with advanced cardiac pathology. Another presentation of the disease can include symptoms consistent with carpal tunnel syndrome; however, the true incidence of amyloidosis in patients with carpal tunnel syndrome remains unclear.

METHODS

We performed a retrospective chart review on all patients who underwent an open carpal tunnel release, with tenosynovium biopsy by a single surgeon between 01/2000 and 12/2018. Samples were stored in formalin following hematoxylin-eosin or congo red staining. A total of 199 patients were excluded for incomplete records, and carpal tunnel release performed for traumatic or infectious etiologies. Histologic findings of the attending pathologist were examined and categorized as follows: amyloidosis, fibrous tissue, tenosynovitis/inflammation edematous, benign tenosynovium, and gout.

RESULTS

Exactly 898 open carpal tunnel releases were performed, and 699 patients were included for final analysis. In all patients, biopsies for histology with hematoxylin-eosin (HE) staining were taken; in those HE stains where amylogenic proteins were suspected (73 or 10.4%), a subsequent congo red staining was additionally performed which confirmed the diagnosis of amyloidosis in 10 patients (1.4% of the carpal tunnel procedures). Overall, 10 patients were identified and constituted 1.4% of all HE stains (n = 10/699) and 13.7% of all congo red stains (n = 10/73).

CONCLUSION

Our results suggest that the incidence of amyloidosis in the general CTS patient population may be as high as 1.4% with routine screening by synovial biopsy and the diagnosis should be considered as a potential cause. Level of Evidence: III, retrospective study.

Evidence-Based Approach to Timing of Nerve Surgery: A Review

ABSTRACT

Events causing acute stress to the health care system, such as the COVID-19 pandemic, place clinical decisions under increased scrutiny. The priority and timing of surgical procedures are critically evaluated under these conditions, yet the optimal timing of procedures is a key consideration in any clinical setting. There is currently no single article consolidating a large body of current evidence on timing of nerve surgery. MEDLINE and EMBASE databases were systematically reviewed for clinical data on nerve repair and reconstruction to define the current understanding of timing and other factors affecting outcomes. Special attention was given to sensory, mixed/motor, nerve compression syndromes, and nerve pain. The data presented in this review may assist surgeons in making sound, evidence-based clinical decisions regarding timing of nerve surgery.

Histologic and Functional Outcomes of Conduit Wrapping for Peripheral Nerve Repair: Early Results in a Rat Model

BACKGROUND

 The concept of utilizing a nerve conduit for augmentation of a primary nerve repair has been advocated as a method to prevent neural scarring and decrease adhesions. Despite clinical use, little is known about the effects of a nerve conduit wrapped around a primary repair. To better understand this, we investigated the histologic and functional effects of use of a nerve conduit wrapped around a rat sciatic nerve repair without tension.

METHODS

 Twenty Lewis' rats were divided into two groups of 10 rats each. In each group, unilateral sciatic nerve transection and repair were performed, with the opposite limb utilized as a matched control. In the first group, direct repair alone was performed; in the second group, this repair was augmented with a porcine submucosa conduit wrapped around the repair site. Sciatic functional index (SFI) was measured at 6 weeks with walking track analysis in both groups. Nonsurvival surgeries were then performed in all animals to harvest both the experimental and control nerves to measure histomorphometric parameters of recovery. Histomorphometric parameters assessed included total number of neurons, nerve fiber density, nerve fiber width, G-ratio, and percentage of debris. Unpaired t-test was used to compare outcomes between the two groups.

RESULTS

 All nerves healed uneventfully but compared with direct repair; conduit usage was associated with greater histologic debris, decreased axonal density, worse G-ratio, and worse SFI. No significant differences were found in total axon count or gastrocnemius weight.

CONCLUSION

 In the absence of segmental defects, conduit wrapping primary nerve repairs seem to be associated with worse functional and mixed histologic outcomes at 6 weeks, possibly due to debris from conduit resorption. While clinical implications are unclear, more basic science and clinical studies should be performed prior to widespread adoption of this practice.

Management of Recalcitrant Cubital Tunnel Syndrome

Cubital tunnel syndrome is a common upper extremity compressive neuropathy. Recalcitrant cubital tunnel syndrome poses diagnostic and treatment challenges. Potential etiologies of persistent or recurrent symptoms after surgical treatment include an inaccurate preoperative diagnosis, incomplete nerve decompression, iatrogenic injury, postsurgical perineural adhesions, irreversible nerve pathology, or conditions associated with secondary nerve compression. Confirmation of recalcitrant ulnar nerve pathology relies on a thorough history to consider symptoms and chronology, careful examination to quantify nerve function and to assess for focal nerve provocation, and objective testing to highlight a possible nerve lesion such as ultrasonography and electrodiagnostic testing. Conservative treatment may provide symptomatic relief; however, surgical management such as revision neuroplasty, neurolysis, nerve reconstruction, and/or anterior transposition may be indicated. Optimizing the biology of the local nerve environment is critical. No surgical treatment procedure has shown superiority over another; however, individualized treatment is emphasized to improve symptoms and maximize nerve recovery potential.

Dissection of an Ulnar Nerve Previously Transposed and Wrapped with Human Amniotic Membrane: A Report of 3 Cases

CASES

We present 3 patients who underwent ulnar nerve transposition and wrapping of the nerve with human amniotic membrane (HAM). All 3 patients subsequently required a reoperation for the original pathologic condition (not for ulnar nerve symptoms), necessitating the exploration and dissection of the transposed ulnar nerve. We demonstrate the lack of scar formation and ease of separation between nerve and surrounding tissue, as well as histology in one case taken from the perineural tissues (previous amniotic membrane), demonstrating no inflammatory cells or absence of scar tissue formation.

CONCLUSION

Exploration and dissection of a previously transposed ulnar nerve can be facilitated by wrapping the nerve with HAM to prevent scarring and perineural fibrosis.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

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

Challenging the dogma: anterior transposition of the ulnar nerve is indicated in recurrent cubital tunnel syndrome

The current evidence for treatment of primary idiopathic cubital tunnel syndrome favours an in situ release. However, anterior transposition of the ulnar nerve remains a popular procedure in recurrent cubital tunnel syndrome. For more than 20 years, I have performed an extended in situ release only, and achieved similar or better results than with nerve transposition. In performing a systematic review of the evidence for surgery for recurrent cubital tunnel syndrome, I could only include 16 out of 296 studies regarding treatment of recurrent cases of cubital tunnel syndrome. A meta-analysis was not possible, due to selection bias and disparity of outcome measurements of the studies. However, I could not find robust evidence that supports the need of an anterior transposition of the ulnar nerve in recurrent cubital tunnel syndrome over an in situ decompression. My own experience of an extended in situ release with complete neurolysis with reasonable outcomes, in combination with the lack of literature support of anterior transposition in recurrent cases, have led me to the consideration that this dogma should be revised.

Benefits of a collagen membrane for recurrent ulnar nerve entrapment at the elbow: A series of 40 cases

The rate of failure or recurrence after ulnar nerve release at the elbow is up to 25%. Various biomaterials have been developed to protect nerves from postoperative adhesions. The aim of this study was to review a case series of 40 surgical revision procedures of the ulnar nerve at the elbow, protected by a collagen membrane (Cova™ ORTHO). Forty patients who had this revision surgery between January 2013 and December 2017 were reviewed: 34 were evaluated in person, 6 were evaluated over the phone. The operation consisted in release of the ulnar nerve, anterior subcutaneous transposition and nerve protection using a collagen membrane. We assessed the following parameters with an average follow-up of 4 years and 3 months: paresthesia, night awakening, quality of life (QuickDASH score) and neuropathic pain (DN4 questionnaire). The outcome was determined with the Gabel & Amadio score. The patients' satisfaction was evaluated. A significant decrease in paresthesia and night awakening was found (p < 0.05). The average Gabel & Amadio score improved from 4.4 to 6.7 with 5 excellent, 19 good, 9 fair, and 1 poor result. The average DN4 was 5/10 and the QuickDASH score was 40.1. Eighty percent of patients were satisfied or very satisfied with the outcome. Surgical revision of the ulnar nerve at the elbow remains a delicate operation without a gold standard. This case series found good or excellent results in 70% of patients. Surgical revision of the ulnar nerve with a collagen membrane is a reliable alternative among other possibilities for ulnar nerve release at the elbow.

Nerve wrapping for recurrent compression neuropathy: A systematic review

BACKGROUND

The recurrence of symptoms following primary nerve compression surgery can occur in up to 25% of cases. Nerve wrapping can be utilised for revision surgery. An ideal barrier should minimise the chance of fibrosis, scarring and allow for adequate nerve gliding. This review evaluates the use of autologous or commercially available allograft and xenograft options as barriers against nerve scarring following revision surgery.

METHODS

PubMed, Ovid Embase and Cochrane databases were searched using the All Fields Index. Nine hundred titles underwent title screening with 11 studies being included in the final analysis. The risk of bias was assessed using the Methodological Index for Non-Randomised Studies (MINORS) tool. PRISMA guidelines were followed at all stages and the review was registered with PROSPERO (CRD 42020182818).

RESULTS

The 11 studies comprised of all case series. In total, 114 patients were included, with ages ranging from 28 to 90. Previously, the number of revision surgeries ranged from 0 to 5. Autologous veins were used in 6 studies, collagen in 3 studies and human amniotic membrane in 2 studies. Improvements in subjective and objective outcomes were seen with all wrap types. Pain was the most common residual symptom (46% of patients). The most common complication was pain at the donor site following vein harvest (19% of patients).

CONCLUSION

This is the first systematic review to summarise the outcomes of nerve wraps for revision compression neuropathy. While improvements in outcomes were reported, further comparative studies are needed to determine the best nerve wrap.

Recurrent and persistent carpal tunnel syndrome: "Triple-therapy approach"

Background

Various procedures have been described for patients undergoing a revision carpal tunnel release. These can include repeat open decompression with external or internal neurolysis, tenosynovectomy, endoscopic release, various flap techniques, saphenous vein wrapping and use of prosthetic implants. This study reports a case series of 30 consecutive patients who underwent revision carpal tunnel release at single institution from 2012 to 2018. Our surgical plan in all the patients involved a combination of these three techniques (triple therapy approach): neurolysis (external or internal) and tenosynovectomy, collagen matrix conduit wrap (NeuraWrap; Integra LifeSciences or Axoguard Nerve Protector, AxoGen Inc), and hypothenar fat flap.

Materials and methods

A total of 30 patient records were identified. The index surgery was performed by a variety of surgeons at varied private institutions as well as the VA hospital. However, all of the revision interventions in this series were performed by the senior author (Z.J.P.). Demographic data (age, sex, hand dominance, comorbidities, alcohol, and smoking history) were collected. Preoperative and postoperative symptoms were recorded for all patients, including: subjective outcomes, need for additional surgery and complications. Mean VAS preoperatively and postoperatively were compared using a paired t-test. All statistical analyses were performed with SPSS 20 (IBM, Chicago, IL).

Results

Patient reported measures of resolution of symptoms and VAS scores documented at 3 months. Of the 30 patients who underwent surgery for persistent or recurrent carpal tunnel syndrome, symptoms resolved completely in 25 patients. 2 patients were lost to follow up. 3 patients showed no improvement. The mean preoperative VAS score was 4.37 and declined to 1.23 after surgery (P < .0001).

Conclusion

Our study demonstrates that a combination of neurolysis and tenosynovectomy along with a nerve wrap and hypothenar fat flap should be considered in patients presenting with recurrent or persistent carpal tunnel syndrome.

A case series of seven patients with recurrent median nerve neuropathy treated by the revision surgery of median nerve neurolysis and wrapping with radial artery perforator adipose flap

Adhesion neuropathy of the median nerve with persistent pain can be a challenging problem. Currently, coverage of the median nerve with a well-vascularized soft tissue is deemed necessary after secondary neurolysis. Herein, we reviewed the outcomes of seven patients with a persistent median nerve neuropathy after a primary open carpal tunnel release or a median nerve repair, treated with neurolysis and median nerve wrapping with radial artery perforator adipose flaps. During the revision surgery, after a careful and complete neurolysis of the scarred median nerve, the distally based radial artery perforator adipose flap without its fascia was raised and rotated to wrap the median nerve. The mean size of the perforator flap was 1146 mm², which was enough to wrap the median nerve in all patients. At 26 months postsurgery, both the visual analog scale score for pain with tingling, and the patient-reported outcome measures improved. There was no recurrence of the median nerve adhesion neuropathy and no major complications were noted. Tinel's sign at the palmar wrist completely disappeared in four patients and was relieved in three patients. The median distal motor latency becomes recordable, and closer to a normal compound motor action potential postoperatively in all patients. Secondary neurolysis and median nerve wrapping with a radial artery perforator adipose flap, which was modified to be softer and thinner than the radial artery perforator adipofascial flap, was a successful treatment for the recurrent median nerve neuropathy in terms of both pain relief and restoration of the hand function.

Wrapping With Basic Fibroblast Growth Factor-Impregnated Collagen Sheet Reduces Rat Sciatic Nerve Allodynia

Autologous vein wrapping is used to treat recurrent chronic constriction neuropathy and traumatic peripheral nerve injury. However, its use is restricted due to the inability to obtain sufficiently long veins for larger grafts. We previously reported that vein-derived basic fibroblast growth factor (bFGF) promotes heme oxygenase-1 (HO-1), which reduces allodynia via its anti-inflammatory properties. To mimic vein wrapping, we developed a collagen sheet impregnated with bFGF. Chronic constriction injury (CCI) was induced in male Wistar rats as a model of sciatic nerve injury, and the rats were divided into three groups: (i) untreated after CCI surgery (control group), (ii) treated with a collagen sheet wrap impregnated with phosphate-buffered saline (PBS/CS group), and (iii) treated with a collagen sheet wrap impregnated with bFGF (bFGF/CS group). Pain behavior (von Frey test) was evaluated on postoperative days (PODs) 1, 5, 7, and 14. Quantitative polymerase chain reaction was conducted on sciatic nerve RNA to quantify HO-1 gene, Hmox1, expression. Enzyme-linked immunosorbent assay were used to determine HO-1 protein levels on POD 1. von Frey testing showed significantly greater pain hypersensitivity in the control and PBS/CS groups than the bFGF/CS group. In the bFGF/CS group, Hmox1 messenger RNA and HO-1 protein levels were significantly increased in the sciatic nerve compared with the control and PBS/CS groups on PODs 1 and 5 and POD 1, respectively. The bFGF/CS group showed decreased allodynia and HO-1 induction, as observed with vein wrapping. Therefore, local application of bFGF may be an alternative treatment strategy for compressive neuropathy and peripheral nerve trauma in clinical settings. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2258-2263, 2019.

Management of Recalcitrant Carpal Tunnel Syndrome

Recalcitrant carpal tunnel syndrome presents a clinical challenge. Potential etiologies of persistent or recurrent symptoms after primary carpal tunnel release include incomplete nerve decompression, secondary sites of nerve compression, unrecognized anatomic variations, irreversible nerve pathology associated with chronic compression neuropathy, perineural adhesions, conditions associated with secondary nerve compression, iatrogenic nerve injury, or inaccurate preoperative diagnosis. Understanding the pertinent surgical anatomy and pathophysiology is essential toward developing an effective diagnostic and treatment strategy. A thorough clinical history and examination guide a comprehensive diagnostic evaluation that includes serial examinations, neurophysiologic testing, and imaging studies. Conservative treatment may provide symptomatic relief; however, surgical management involving revision neuroplasty, neurolysis, nerve reconstruction, and/or local soft-tissue flap augmentation may be indicated in refractory cases.

Effectiveness of mini-open carpal tunnel release: An outcome study

Background

Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy with a high morbidity and healthcare-related costs. Currently there is no consensus about the best treatment option. The purpose of this prospective cohort study conducted at a single institution was to evaluate the clinical outcomes and patient satisfaction following a mini-open carpal tunnel release for idiopathic CTS.

Methods

A total of 72 patients (53 female and 19 male patients; mean age, 57.8±15.3 years; range, 24–94 years) had a mini-open carpal tunnel release performed by a single senior surgeon between June 2015 and June 2016. The patients were evaluated preoperatively, and at 3 and 12 months post-intervention. At every follow-up, the Boston Carpal Tunnel Syndrome Questionnaire (BCTSQ) and visual analogue scale (VAS) scores for pain and satisfaction were completed. Digital sensibility (using Semmes- Weinstein monofilaments) was assessed and pinch and grip strengths were measured.

Results

Statistically significant and clinically relevant improvement was found in terms of digital sensibility, grip and pinch strength (except for 2-point pinch), BCTSQ scores and pain scores. The complication rate was minimal, and no major complications occurred. Two patients experienced recurrence. The availability of follow-up records (including patient-reported outcomes, BCTSQ and VAS scores, and the complication rate) at 1-year post-intervention varied between 69% and 74% (50–53 patients) depending on which parameter was assessed. Patient satisfaction was high (mean, 80.9±26.0; range, 0–100).

Conclusions

This study demonstrates that mini-incision carpal tunnel release is clinically effective in the short and long term.

Inflammatory Reactions to Xenogenic Nerve Wraps: A Report of Three Cases

CASE

Recurrent carpal tunnel syndrome is a challenging problem. Nerve wraps have been introduced as a barrier to prevent scar traction neuritis for use during revision carpal tunnel surgery. We present 3 cases of inflammatory responses to bovine collagen and porcine subintestinal mucosal nerve wraps in patients undergoing revision carpal tunnel surgery. No patient had evidence of infection, and pathology revealed acute and chronic inflammation. All 3 patients responded favorably following wrap removal.

CONCLUSIONS

We recommend caution with the routine use of nerve wraps in the setting of revision carpal tunnel surgery.

Long-term outcome after carpal tunnel release and identification of prognostic factors

BACKGROUND

The effectiveness of the surgical treatment of carpal tunnel syndrome (CTS) is well known on short term. However, limited data is available about long-term outcome after carpal tunnel release (CTR). The aims of this study were to explore the long-term outcome after CTR and to identify prognostic factors for long-term outcome.

METHODS

Patients with clinically defined CTS underwent CTR and completed the Boston Carpal Tunnel Questionnaire at baseline (T₀), at about 8 months (T₁), and after a median follow-up of 9 years (T₂), as well as a 6-point scale for perceived improvement (at T₁ and T₂). Potentially prognostic factors were identified by logistic regression analysis and correlation.

RESULTS

At long-term follow-up, 87 patients (40.3%) completed the questionnaires. Mean score on Symptom Severity Scale (2.87 to 1.54; p < 0.001) and Functional Status Scale (2.14 to 1.51; p < 0.001) improved at 8 months and did not change significantly after 8 months. A favorable outcome was reported in 81.6%. A good treatment outcome after 8 months and to a lesser extent a lower FSS score at T₀ were associated with a better long-term outcome.

CONCLUSIONS

CTR is a robust treatment for CTS and its effect persists after a period of 9 years. The most important factor associated with long-term outcome is treatment outcome after about 8 months and to a lesser extent functional complaints preoperatively. Outcome is independent of patient characteristics, electrodiagnostic test results, or findings at the initial neurological examination.

The Management of Persistent and Recurrent Cubital Tunnel Syndrome

Cubital tunnel syndrome (CuTS) is the second most common compressive neuropathy in the upper extremity. There are considerable diagnostic and therapeutic challenges associated with treating patients after a failed primary procedure for CuTS. Distinguishing cases of recurrence versus persistence and identifying concomitant pathology can guide treatment. Conditions that mimic CuTS must be carefully ruled out and coexisting dysfunction of the medial antebrachial cutaneous nerve needs to be addressed. Results of revision procedures are not as reliable as primary procedures for CuTS; however, improvements in pain and paresthesias are noted in approximately 75% of patients. Nerve wraps represent a promising adjuvant treatment option, but long-term outcome data are lacking. External neurolysis and anterior transposition after failed CuTS procedures are supported by case series; multicenter, prospective randomized trials are needed to guide treatment further and improve outcomes.

Medical Malpractice Following Carpal Tunnel Surgery

There is a paucity of literature examining the reasons for litigation following carpal tunnel surgery in the United States. The purpose of this retrospective study was to examine a nationwide legal database to describe the most frequent reasons for malpractice litigation following carpal tunnel surgery. All malpractice claims that occurred following carpal tunnel surgery were included. In total, 46 cases met inclusion criteria, representing 15 male and 31 female patients with an average age of 46.4 years (±14.7 years). Four cases (8.7%) resulted in settlement. Of the 42 cases that went to trial, 33.3% ended in a decision in favor of the plaintiff and 66.7% ended in a decision in favor of the physician. The average payment for all lawsuits was $637,140.97. There was no significant difference in the average payment for cases lost in court ($329,690±$233,910) vs cases that ended in settlement ($422,286±$388,973). The 3 most frequent reasons for malpractice litigation after carpal tunnel surgery were nerve injury (n=18, 39.1%), persistent pain and numbness (n=15, 32.6%), and regional sympathetic dystrophy (n=9, 19.6%). Complications of carpal tunnel release should be emphasized during the consent process. [Orthopedics. 2018; 41(4):e569-e571.].

Results of reoperation for failed ulnar nerve surgery at the elbow: a systematic review and meta-analysis

OBJECTIVE

The clinical results of reoperation for recurrent or persistent ulnar nerve compression at the elbow have not been clearly determined. The aim of this review was to determine overall improvement, residual pain, and sensory and motor deficits following reoperation regardless of the type of primary surgery performed for this condition.

METHODS

In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, a systematic review and meta-analysis of studies was performed. An independent librarian performed a literature search using Ovid MEDLINE, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials (CENTRAL). The Newcastle-Ottawa Scale and the quality appraisal tool described by Moga et al. were used to assess the quality of included case series.

RESULTS

Of the 278 retrieved studies, 16 were eligible for analysis and included a total of 290 patients with failed surgery for ulnar nerve entrapment at the elbow. Relief of symptoms after reoperation was reported in 85% of patients. A decrease in pain was noted in 85% of the patients (95% CI 75%-93%). Only 2.4% of patients with preoperative pain experienced worse pain after reoperation. Motor and sensory function improvement was noted in 77% (95% CI 63%-88%) and 77% (95% CI 61%-90%) of cases, respectively. Complete recovery from signs and symptoms at the final follow-up was noted in 23% of elbows (95% CI 16%-31%).

CONCLUSIONS

Although the level of evidence of the included studies was low, the majority of patients had relief from their complaints after reoperation for recurrent or persistent ulnar nerve compression at the elbow following a previous surgery. The success rate of surgical treatment for a failed surgery was quite remarkable since almost a quarter of the patients completely recovered. Therefore, the authors recommend reoperation as a serious option for patients with this condition.

Barriers to Epineural Scarring: Role in Treatment of Traumatic Nerve Injury and Chronic Compressive Neuropathy

The physiological limitations of neural regeneration make peripheral nerve surgery challenging to both the surgeon and the patient. Presence of nerve gaps and local wound factors may all influence outcome, suggesting that barriers to reduce perineural scarring, minimize fibrosis, and avoid ischemia would be beneficial. To examine the evidence supporting their use, we reviewed the autologous and commercially-available options for barriers against scarring around a nerve. Numerous clinical case series demonstrated the effectiveness and safety of local/rotational flaps and autologous vein wrapping when used in the presence of recurrent compressive neuropathy. Translational research in animal models supports the biocompatibility of commercially available nerve wraps following nerve repair. To date, there are no reports of clinical use of commercially available nerve wraps in acute nerve repair, but a growing number of case series demonstrate their effectiveness and safety in chronic compressive neuropathy. Limited clinical evidence exists to support the efficacy of vein or flap coverage in acute nerve repairs.

Neurolysis with Amniotic Membrane Nerve Wrapping for Treatment of Secondary Wartenberg Syndrome: A Preliminary Report

Background: Entrapment of the superficial sensory branch of the radial nerve (SRN) commonly results in debilitating pain of the dorsoradial wrist. Symptom relief following SRN neurolysis is often incomplete or temporary due to recurrent perineural scarring.

Methods: We performed a retrospective review with prospective follow-up of all patients with SRN neuropathy who were treated with neurolysis and nerve wrapping using an amnion-based allograft adhesion barrier over a one-year interval. Measured outcomes included pain rated by Visual Analog Scale (VAS) and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) functional outcome scores.

Results: Three females satisfied inclusion. At mean follow-up of 28.9 months, all three patients exhibited improved pain (mean VAS change −4.7 ± 0.6), function (mean QuickDASH change −40 ± 5), and subjective satisfaction. No adverse events or reactions to the implanted tissue occurred.

Conclusions: SRN entrapment neuropathy was safely and effectively treated with neurolysis and amnion nerve wrapping in this small series. Use of this technique for perineural scar prevention warrants additional study in larger groups of patients and in other upper extremity entrapment neuropathies.

Management of painful scar-tethered cutaneous nerves of the upper limb

We report the results of treatment by division and proximal relocation of 44 painful, scar-tethered cutaneous nerves of the upper limb in 22 patients. In all patients, neuropathic pain had developed either following surgery or trauma, but without apparent direct nerve injury. The mean duration of pain symptoms prior to relocation was 17 (range 7-44) months. Adequate treatment involved relocation of 35 nerves at a first operation for each of the 22 patients, with six patients requiring further surgery to relocate 9 nerves. At a minimum follow-up of 6 months, nerve relocation resulted in complete resolution of all forms of pain at the primary site in 21/22 (95%) patients and no pain or hypersensitivity at the final relocation site in 19 of the 22 patients (86%).

Recurrent cubital tunnel syndrome treated with revision neurolysis and amniotic membrane nerve wrapping

BACKGROUND

Perineural scarring of the ulnar nerve is a predominant cause of symptom recurrence after surgical treatment for primary cubital tunnel syndrome (CuTS). We report our preliminary experience in revision ulnar nerve decompression and nerve wrapping with an amniotic membrane allograft adhesion barrier for treatment of recurrent CuTS.

METHODS

We performed a retrospective review with prospective follow-up of patients with recurrent CuTS who were treated with revision neurolysis with amniotic membrane nerve wrapping. Preoperative elbow motion, grip and pinch strengths, pain level on the visual analog scale level, and the 11-item version of the Disabilities of the Arm, Shoulder and Hand functional outcome score were compared with postoperative values using paired t testing. Symptom characteristics, physical examination findings, complications, and level of satisfaction were also obtained.

RESULTS

Eight patients (mean age, 47.5 years) who had undergone at least 2 prior ulnar nerve operations satisfied study inclusion. At mean postoperative follow-up of 30 months, significant improvements were noted across all patients in visual analog scale pain levels (-3.5 vs. preoperatively; P < .0001), 11-item version of the Disabilities of the Arm, Shoulder and Hand scores (-30 vs. preoperatively; P < .0001), and grip strength (+25 pounds vs. preoperatively; P < .0001). Pinch strength and elbow motion were also significantly improved for those patients with comparative preoperative data available. All patients expressed subjective satisfaction with their results. No adverse reactions or complications occurred in any patients.

CONCLUSIONS

Ulnar nerve wrapping with amniotic membrane allograft, when combined with revision neurolysis, was a safe and subjectively effective treatment for patients with debilitating recurrent CuTS.

Carpal tunnel syndrome: clinical features, diagnosis, and management

Carpal tunnel syndrome is the most common peripheral nerve entrapment syndrome worldwide. The clinical symptoms and physical examination findings in patients with this syndrome are recognised widely and various treatments exist, including non-surgical and surgical options. Despite these advantages, there is a paucity of evidence about the best approaches for assessment of carpal tunnel syndrome and to guide treatment decisions. More objective methods for assessment, including electrodiagnostic testing and nerve imaging, provide additional information about the extent of axonal involvement and structural change, but their exact benefit to patients is unknown. Although the best means of integrating clinical, functional, and anatomical information for selecting treatment choices has not yet been identified, patients can be diagnosed quickly and respond well to treatment. The high prevalence of carpal tunnel syndrome, its effects on quality of life, and the cost that disease burden generates to health systems make it important to identify the research priorities that will be resolved in clinical trials.

Autogenous Vein Wrapping versus In Situ Decompression for Management of Secondary Cubital Tunnel Syndrome after Surgical Fixation of Elbow Fractures: Short-Term Functional and Neurophysiological Outcome

PURPOSE

The aim of this study was to compare the functional and neurophysiological outcome of in situ decompression versus in situ decompression augmented with autogenous vein wrapping in management of secondary cubital tunnel syndrome at the elbow following fixation of elbow fractures.

METHODS

A prospective comparative randomized study was performed on 29 patients who were divided into two groups: group I (in situ decompression) and group II (in situ decompression augmented with autogenous vein wrapping). We measured the patients' demographics, subjective reports of symptoms, and objective evaluation of the functional and neurophysiological outcomes of both groups.

RESULTS

Group II patients achieved statistically better results in both neurophysiological scoring and clinical sensory rating but not in all other parameters.

CONCLUSION

Autogenous vein wrapping for secondary cubital tunnel syndrome after elbow fracture fixation only provides a better sensory outcome.

LEVEL OF EVIDENCE

Level II, therapeutic prospective comparative study.