Neurolysis of the distal superficial radial nerve for dysaesthesia due to nerve tethering

Superficial radial neuropathy: an unobserved etiology of chronic dorsoradial wrist pain

Background

Superficial radial neuropathy is considered an uncommon cause of chronic dorsoradial wrist pain. Its clinical diagnosis is usually missed. The purpose of the research was to investigate the existence of superficial radial neuropathy as a cause of chronic dorsoradial wrist pain. The study included 98 upper limbs obtained from 72 patients [58 women (80.6%)] with a primary complaint of chronic dorsoradial wrist pain and 91 asymptomatic upper limbs obtained from 63 apparently healthy individuals [46 women (73.0%)] as a control group. Clinical assessment and superficial radial nerve conduction study were done.

Results

No significant differences between patients and control group were present regarding sex and age. Among the participated patients, there were 29 upper limbs (29.6%) from 26 patients (36.1%) who had superficial radial neuropathy proved clinically and electrophysiologically. From them, three patients (11.5%) had bilateral superficial radial neuropathy. It was the solitary cause of chronic dorsoradial wrist pain in 15 upper limbs (51.7%) from 13 patients (50%). The remaining patients were associated with other musculoskeletal wrist conditions. The most common associated local wrist pathology was de Quervain’s disease in 8 upper limbs (27.6%) from 8 patients (30.8%).

Conclusions

Superficial radial neuropathy is common among patients with chronic dorsoradial wrist pain and should be considered in the differential diagnosis.

Vein conduit with microsurgical suture repair of superficial branch of the radial nerve injuries at the wrist

The superficial branch of the radial nerve (SBRN) at the wrist is susceptible to trauma and lacerations. These lesions can develop into painful neuromas with debilitating consequences. The aim of our study was to demonstrate the effectiveness of systematic use of vein conduits associated with microsurgical suture repair in SBRN injuries to prevent the occurrence of these neuromas. Our study was retrospective and performed at a single site. An independent examiner performed the clinical assessment. The study included 33 patients and the mean follow-up was 63 months. We looked for a so-called "trigger point". None of the patients developed a painful neuroma or experienced any pain. All the patients were either satisfied or very satisfied with their treatment. Systematic use of vein conduit in SBRN injuries at the wrist helps prevent the occurrence of painful neuroma and the disorder's inherent consequences, which can be severe not only clinically, but also socially and professionally.

A novel experimental rat model of peripheral nerve scarring that reliably mimics post-surgical complications and recurring adhesions

Inflammation, fibrosis and perineural adhesions with the surrounding tissue are common pathological processes following nerve injury and surgical interventions on peripheral nerves in human patients. These features can reoccur following external neurolysis, currently the most common surgical treatment for peripheral nerve scarring, thus leading to renewed nerve function impairment and chronic pain. To enable a successful evaluation of new therapeutic approaches, it is crucial to use a reproducible animal model that mimics the main clinical symptoms occurring in human patients. However, a clinically relevant model combining both histological and functional alterations has not been published to date. We therefore developed a reliable rat model that exhibits the essential pathological processes of peripheral nerve scarring. In our study, we present a novel method for the induction of nerve scarring by applying glutaraldehyde-containing glue that is known to cause nerve injury in humans. After a 3-week contact period with the sciatic nerve in female Sprague Dawley rats, we could demonstrate severe intra- and perineural scarring that resulted in grade 3 adhesions and major impairments in the electrophysiological peak amplitude compared with sham control (P=0.0478). Immunohistochemical analysis of the nerve structure revealed vigorous nerve inflammation and recruitment of T cells and macrophages. Also, distinct nerve degeneration was determined by immunostaining. These pathological alterations were further reflected in significant functional deficiencies, as determined by the analysis of relevant gait parameters as well as the quantification of the sciatic functional index starting at week 1 post-operation (P<0.01). Moreover, with this model we could, for the first time, demonstrate not only the primary formation, but also the recurrence, of severe adhesions 1 week after glue removal, imitating a major clinical challenge. As a comparison, we tested a published model for generating perineural fibrotic adhesions, which did not result in significant pathological changes. Taken together, we established an easily reproducible and reliable rat model for peripheral nerve scarring that allows for the effective testing of new therapeutic strategies.

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%).

Secondary Interventions for Mutilating Hand Injuries

Care of the reconstructed hand following mutilating injury is akin to the care of a vintage car. Its mechanisms are delicate, spare parts are limited, touch-ups are required often, and a major overhaul is indicated rarely. Secondary interventions are indicated for completion of staged primary procedures, management of complications, targeted improvement of function, and enhancement of appearance of the reconstructed hand. The approach to secondary reconstruction depends on the patient's age, and vocational and recreational requirements. It is also influenced by the constant evolution of surgeons' reconstructive philosophy, experience, and technology.

Application of free temporoparietal fascial flap for recurrent neural adhesion of superficial radial nerve--A case report

Because of its anatomical location, the superficial radial nerve is vulnerable to trauma as well as injury during various surgical procedures. Once the nerve adheres to surrounding scar tissue, radiating pain often occurs due to nerve traction caused by loss of smooth gliding. Since it has been reported that the success rate with neurolysis only is lower, additional preventive procedures for recurrent neural readhesion are recommended. In the current report, we describe our experience performing neurolysis followed by nerve coverage using a free temporoparietal fascial flap for recurrent neural adhesion of the superficial radial nerve. A 45-year-old male complained of motion pain of the left wrist and thumb joints caused by recurrent neural adhesion of the superficial radial nerve after a chain saw trauma and following multiple reconstructive procedures. The radiating pain completely disappeared after neurolysis performed by a previous surgeon; however, it recurred 4 weeks later. Four months after the previous neurolysis the patient underwent external neurolysis and covering of the nerve with a free temporoparietal fascial flap to prevent neural readhesion because local soft tissue could not be used due to the massive scar tissues on the forearm. One year after the secondary neurolysis, the symptoms of radiating pain during wrist and thumb motion were drastically improved. A free adipofascial flap such as a temporoparietal flap may be an option for prevention of neural readhesion after neurolysis of the superficial radial nerve in cases where a local flap cannot be used on the forearm.

An Anatomical Study to Demonstrate the Proximity of Kirschner Wires to Structures at Risk in Percutaneous Pinning of Distal Radius Fractures

Distal radius fractures are often treated using percutaneous Kirschner wires (K-wires). The sensory nerves in this area, extensor tendons, radial artery and cephalic vein are at risk of injury in this procedure. We undertook a cadaveric investigation to identify probability of damage to these 'at risk' structures by measuring their distances in relation to standard K-wire sites. Nine upper limbs from six formalin-preserved cadavers were studied. Four K-wires were placed percutaneously simulating fixation of a distal radius fracture. Careful dissection was done preserving the original position of neurovascular and tendinous structures. Distances to relevant soft-tissue structures from each K-wire were measured using an electronic digital caliper. Distance of superficial nerves from radial styloid and Lister's tubercle was measured to determine their 'safe distance' from these fixed landmarks. None of the superficial nerves were injured by a K-wire. Cephalic vein had been pierced on 4 occasions (4/18) and extensor tendons on 3 occasions (3/18). Wilcoxon signed-rank test was used to compare distance of the superficial nerves from radial styloid and Lister tubercle, and the latter was found to be the safer option. This study highlights the inherent danger in percutaneous K-wire fixation of wrist fractures. Limited size of the area, where K-wires can be positioned, and anatomic variations of neurovascular structures pose obstacles in developing guidelines for reducing risk of injury. We advocate use of mini-open approach and guiding devices to avert complications of inadvertent impalement and damage to these structures.

Adult scaphoid fracture

OBJECTIVES

Scaphoid fractures are the most common carpal fracture, representing 70% of carpal bone fractures. The diagnostic accuracy of physical examination findings and emergency medicine (EM) imaging studies for scaphoid fracture has not been previously described in the EM literature. Plain x-rays are insufficient to rule out scaphoid fractures in a patient with a suggestive mechanism and radial-sided tenderness on physical examination. This study was a meta-analysis of historical features, physical examination findings, and imaging studies for scaphoid fractures not visualized on plain x-ray in adult emergency department (ED) patients, specifically to address which types of imaging tests should be recommended in patients with persistent concern for acute fracture after ED discharge.

METHODS

A medical librarian and two emergency physicians (EPs) conducted a medical literature search of PUBMED and EMBASE. The original studies' bibliographies were reviewed for additional references and unpublished manuscripts were located via a hand search of EM research abstracts from national meetings. All abstracts were independently reviewed by the two physicians, and Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2) was used to assess individual study quality. When two or more qualitatively similar studies were identified, meta-analysis was conducted using Meta-DiSc software. Primary outcomes were sensitivity, specificity, and likelihood ratios (LRs) for predictors of scaphoid fracture detected on follow-up in patients with normal ED x-rays.

RESULTS

A total of 957 unique citations were identified, yielding 75 studies eligible for inclusion in this systematic review. Studies were significantly heterogeneous in design, study population, and criterion standard. The majority of studies were conducted in non-ED settings (e.g., orthopedic clinics). No studies used accepted diagnostic research publishing guidelines, and the overall QUADAS-2 methodologic quality was low, indicating an increased risk of bias in the estimates of diagnostic accuracy. The prevalence of scaphoid fractures ranged from 12% to 57% with the point estimate of 25% pretest probability for adult ED patients with concern for scaphoid injuries, nondiagnostic index x-rays, and scaphoid fractures on later imaging studies. Except for the absence of snuffbox tenderness (LR- = 0.15), physical examination findings lack accuracy to rule in or rule out scaphoid fractures, and no validated clinical decision rules exist. In patients with persistent concern for injury, magnetic resonance imaging (MRI) is superior to bone scan, computed tomography (CT), or ultrasound (US) to both rule in and rule out scaphoid fractures. Both MRI and CT share the added benefit of identifying alternative etiologies for posttraumatic wrist pain.

CONCLUSIONS

Except for the absence of snuffbox tenderness, which can significantly reduce the probability of scaphoid fracture, history and physical examination alone are inadequate to rule in or rule out scaphoid fracture. MRI is the most accurate imaging test to diagnose scaphoid fractures in ED patients with no evidence of fracture on initial x-rays. If MRI is unavailable, CT is adequate to rule in scaphoid fractures, but inadequate for ruling out scaphoid fractures.

Uncommon upper extremity compression neuropathies

Hand surgeons routinely treat carpal and cubital tunnel syndromes, which are the most common upper extremity nerve compression syndromes. However, more infrequent nerve compression syndromes of the upper extremity may be encountered. Because they are unusual, the diagnosis of these nerve compression syndromes is often missed or delayed. This article reviews the causes, proposed treatments, and surgical outcomes for syndromes involving compression of the posterior interosseous nerve, the superficial branch of the radial nerve, the ulnar nerve at the wrist, and the median nerve proximal to the wrist.

Cutaneous nerve transection for the management of intractable upper extremity pain caused by invasive squamous cell carcinoma

A recurrent clinical dilemma in the management of patients with painful metastatic lesions is achieving a balance between effective analgesic therapies versus intolerable side effects, in particular altered mental status. We present the case of an immunosuppressed patient post-lung transplant who was suffering from intractable pain caused by widely metastatic squamous cell carcinoma. The patient's progressive, excruciating neuropathic pain was localized to the area of the left wrist and forearm. Additionally, the patient complained of moderate pain at sites of tumor involvement on her right arm and scalp. Attempts to adequately manage her left upper extremity pain included a combination of pharmacologic treatments intended to treat neuropathic pain (gabapentin, SNRI, ketamine, opioids) and focused regional analgesia (infraclavicular infusion of local anesthetic). However, the patient developed intolerable side effects including altered mental status and delirium associated with the systemic agents and suboptimal control with the infraclavicular infusion. Given that the most severe pain was well localized, we undertook a diagnostic block of the cutaneous nerves of the left forearm. As this intervention significantly reduced her pain, we subsequently performed neurectomies to the left superficial radial nerve, lateral cutaneous nerve of the forearm and the posterior cutaneous nerve of the forearm. This resulted in immediate and continued relief of her left upper extremity pain without an altered mental status. Residual focal pain from lesions over her right arm and scalp was successfully managed with daily topical applications of lidocaine and capsaicin cream. Successful pain control continued until the patient's death five months later.

A comparative microanatomical study on cross-sections of superficial branch of radial nerve in proximal and distal parts of the forearm: a cadaveric study

PURPOSE OF STUDY

Changes in peripheral nerve anatomy with age may be the cause for poor prognosis after nerve repair in elderly cases. The aim of the present study is to find out and compare the cross-sectional microanatomy as well as age-related changes in the non-fascicular components of superficial branch of radial nerve at cubital fossa (SBRN-1) and above wrist (SBRN-2).

METHODS

Thirty-eight fresh human (14 male and five female) cadaveric SBRN-1 and SBRN-2 were collected from both sides of 19 cadavers and study has been performed at different magnifications after routine histological (Masson's trichrome stain) processing was done for morphometric analysis (total cross-sectional area [Asc], fascicular area [Af], non-Af [Anonf], adipose [FAT] area and non-adipose area [nFAT]).

RESULTS

SBRN-1 and SBRN-2 belonged to polyfascicular type and showed difference in amount of connective and adipose tissues in Anonf. The number of fascicles in SBRN-1 ranged from 2 to 6 (3.66±0.21, mean±SEM) and in SBRN-2 ranged from 7.5 to 11.5 (9.24±0.26). On comparing the percentage level of adipose tissue (FAT) in total cross-section area (Asc) and in Anonf of SBRN-1 and SBRN-2, the level of adipose tissue was increased with age.

CONCLUSIONS

The amount of adipose tissue in SBRN-1 and SBRN-2 Anonf was found to be high in most of the elderly cases. On comparison, there was not much difference between SBRN-1 and SBRN-2, but, the fascicle count was found to be increasing gradually from proximal to distal part of the SBRN.