Lateral Antebrachial Cutaneous Nerve Research Articles

Selective Denervation for the Thumb Carpometacarpal Joint: Clinical Outcome and Comparison Based on Eaton Stage.

Various operative treatment options for advanced thumb carpometacarpal (CMC) joint arthritis have been presented without a definite surgical guideline. Selective denervation is a less invasive method for thumb CMC arthritis. However, it is unclear whether the clinical outcome varies with the stage of thumb CMC arthritis. This study aimed to evaluate the effectiveness of selective denervation on CMC arthritis for pain relief and functional outcome and to determine whether selective denervation depends on the stage of thumb CMC arthritis. We evaluated 29 thumbs of 28 patients with thumb CMC arthritis treated with selective denervation. The disease stage was determined with the classification system described by Eaton. The denervation was performed in the articular branches of the palmar cutaneous branch of the median nerve, lateral antebrachial cutaneous nerve, and superficial branch of radial nerve. The clinical outcomes were evaluated using the visual analog scale (VAS) and Disabilities of the Arm, Shoulder, and Hand (DASH) scores, along with evaluation of the improvement in both postoperative range of motion and strength recovery. The mean duration of follow-up was 24 months (range, 18-48 months). The average VAS and DASH scores decreased from 6.1 to 1.3 and from 54.3 to 24.1, respectively. The range of motion during palmar abduction and opposition of the metacarpophalangeal joint improved with an increase in mean value from 44.1 to 53.7 degrees, and the Kapandji score increased from 7.2 to 9.2, respectively. The grip and key pinch strengths increased from mean preoperative values of 14.3 and 3.1 kg to 27.1 and 6.2 kg, respectively, as measured at the 12-month follow-up. The rate of change in the VAS and DASH scores was significantly higher in stages I to III than in stage IV ( P = 0.01, P < 0.01, respectively). The selective denervation for thumb CMC arthritis was effective in pain relief and functional recovery with several advantages, including less invasive procedure, quick recovery time, and regaining of strength. The clinical outcomes were more effective in the early-stage group (Eaton stages I and II) compared with the advance-stage group (Eaton stages III and IV).

Bilateral Sequential Brachial Plexus Neuritis Following Immune Checkpoint Inhibitor Combination Treatment (P13-8.003)

<h3>Objective:</h3> To report a rare, debilitating neurotoxicity to combination immunotherapy. <h3>Background:</h3> Neurologic immune related adverse events associated with ICI are rare; rapid diagnosis and treatment can limit morbidity. Combined ICI treatment is associated with more severe and rapid neurotoxicity. Only 4 BPN cases have been reported. Three were unilateral, predominantly involving the lower trunk (C8-T1) and highly steroid responsive. One affected the anterior interosseous and lateral antebrachial cutaneous nerves. <h3>Design/Methods:</h3> A 76-year-old woman with lung adenocarcinoma received 3 doses of Nivolumab and one dose of Ipilimumab. She developed numbness and pain, followed by worsening bilateral asymmetric arm weakness 3 weeks after receiving her last Nivolumab dose. Her weakness was diffuse, worse on the right, associated with loss of reflexes. It started on the right arm and involved left arm a week after. <h3>Results:</h3> EMG confirmed bilateral brachial plexopathy, predominantly affecting roots derived from C6–C7 on right and C5–C6 on left. CSF showed WBC 7, elevated protein 58 g/dL, no malignant cells, normal IgG index and infectious studies. MRI cervical spine and brachial plexus were unremarkable. She received IV methylprednisolone 1 mg/kg for 5 days, IV immunoglobulin total of 2 grams/kg with rapid improvement in her strength and pain. <h3>Conclusions:</h3> This may be the first report of bilateral sequential BPN with predominantly upper-mid trunk involvement after dual treatment with Nivolumab and Ipilimumab. Rapid workup, exclusion of confounding factors, and treatment with steroids and immunomodulating agents can lead to significant recovery of function from a debilitating process. <b>Disclosure:</b> Dr. Ozel has nothing to disclose. Dr. Chen has nothing to disclose. Dr. Woodman has nothing to disclose.

MRI negative Varicella zoster virus (VZV) plexopathy in a young man with history of malignancy (P2-4.001)

<h3>Objective:</h3> To emphasize the importance of including VZV plexopathy in differential diagnosis in young individuals and to prevent the delay in diagnosis and treatment <h3>Background:</h3> VZV-associated plexopathy in mainly patients over 60 years old. Post herpetic neuralgia is a well-known complication of Herpes Zoster (HZ), however segmental zoster paresis secondary to HZ was reported in 1–20% of the cases in literature. MRI findings may be positive in up to 70% of the patients. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> 43 years-old man with history of grade 2 left frontal oligodendroglioma which was treated with 2 partial resections, radiation and adjuvant procarbazine/lomustine presented with left upper extremity pain and developed a blistering rash in dermatomal pattern in left proximal upper extremity 2 weeks after the initial symptoms. He was diagnosed with shingles and treated with steroids and acyclovir with minimal improvement. 6 weeks after presentation, physical exam revealed left deltoid, supraspinatus and infraspinatus weakness with normal muscle stretch reflexes and decreased sensation on C5 dermatome. EMG revealed absent left lateral antebrachial cutaneous sensory nerve action potentials (SNAP) amplitude, and a small left radial SNAP amplitude compared to the right side. Evidence of ongoing denervation with reinnervation was seen in the left upper trunk supplied muscles. MRI of the brachial plexus was negative for any abnormalities. Patient was diagnosed with VZV-associated plexopathy, improved with pregabalin and physical therapy. <h3>Conclusions:</h3> Our patient was significantly younger than expected in HZ group. MRI usually shows T2 hyperintensities and thickening of the nerve roots in patients with VZV-associated plexopathy. However, the presentation, onset of symptoms, characteristics of the rash and clinical course was diagnostic of HZ, and the weakness pattern, supported by the EMG findings were diagnostic for VZV-associated plexopathy. <b>Disclosure:</b> Dr. Gul has nothing to disclose. Ms. Ahmed has nothing to disclose. Dr. McGraw has nothing to disclose. Dr. Alshiekh Nasany has nothing to disclose.

Computer-Assisted Surgical Anatomical Mapping of the Antebrachial Cutaneous Nerves: An Anatomical Study with a Proposition for Alternative, Cutaneous Nerve-Sparing Anterior Elbow Incisions.

The lateral antebrachial cutaneous nerve (LABCN) and medial antebrachial cutaneous nerve (MABCN) were identified in the coronal plane around the elbow joint in 10 fresh-frozen human arm specimens. Marked photographs of the specimens were analyzed using computer-assisted surgical anatomical mapping (CASAM). Common anterior surgical approaches to the elbow joint and the distal humerus were then compared with merged images, and nerve-sparing alternatives are proposed. The arm was divided longitudinally, from medial to lateral in the coronal plane, into 4 quarters. The LABCN crossed the central-lateral quarter of the interepicondylar line (i.e., was somewhat lateral to the midline at the level of the elbow crease) in 9 of 10 specimens. The MABCN ran medial to the basilic vein and crossed the most medial quarter of the interepicondylar line. Thus, 2 of the quarters were either free of cutaneous nerves (the most lateral quarter) or contained a distal cutaneous branch in only 1 of 10 specimens (the central-medial quarter). The Boyd-Anderson approach, which is often used to access anteromedial structures of the elbow, should be placed slightly further medially than traditionally advised. The distal part of the Henry approach should deviate laterally, so that it runs over the mobile wad. In distal biceps tendon surgery, the risk of cutaneous nerve injury may be reduced if a single distal incision is placed slightly more laterally (in the most lateral quarter), as in the modified Henry approach. If proximal extension is required, LABCN injury may be prevented by using the modified Boyd-Anderson incision, which runs in the central-medial quarter. Cutaneous nerve injury may be prevented by slightly altering the commonly used skin incisions around the elbow on the basis of the safe zones that were identified by depicting the cumulative course of the MABCN and LABCN using CASAM.

Clinical, Electrophysiological, and Sonographic Findings in Patients With Nerve Injury After Vessel Puncture.

This study aimed to describe the clinical, electrophysiological, and ultrasonographic findings of patients with nerve injury after vessel puncture. Data on ten patients (three males and seven females) with nerve injury after vessel puncture were reviewed. Demographic and clinical data were analyzed retrospectively. Bilateral electrophysiological studies were performed based on clinical findings. Ultrasonographic examinations were performed on both the affected and unaffected sides of the injured nerve. The nerves of nine patients were injured following vein puncture, and injury occurred following arterial sampling in one patient. Seven patients had superficial radial sensory nerve injury: five medial, one lateral, and one at both branches. One patient had injury to the dorsal ulnar cutaneous nerve, one to the lateral antebrachial cutaneous nerve, and one to the median nerve. Nerve conduction studies produced abnormal findings in 80% of patients, whereas ultrasonographic examinations produced abnormal findings in all of the patients. Spearman's coefficient for the correlation between the amplitude ratio and nerve cross-sectional area ratio was not significant, at -0.127 (95% confidence interval=-0.701 to 0.546, p=0.721). Ultrasonography supported by electrodiagnosis was found to be a useful method for identifying the lesion location and structural abnormalities of vessel-puncture-related neuropathy.

Chronic Musculocutaneous Nerve Injury: An Important Differential in Progressive Arm Atrophy

An isolated musculocutaneous nerve (MCN) injury is a rare condition that can be easily missed if it presents late. A 28-year-old man reported painless and progressive wasting of the right arm for 6 months. On examination, there was visible wasting of the right biceps brachii muscle along with its slight weakness, depressed biceps jerk, and an impaired pinprick sensation in the lateral antebrachial cutaneous nerve distribution. He described a history of a road traffic accident 14 months beforehand. Based on the history and clinical examination, the differential diagnosis included an isolated MCN injury, upper trunk plexopathy, lateral cord plexopathy, C5/6 radiculopathy, and monomelic amyotrophy involving the C5/6 myotomes on the right side. The results of nerve conduction studies and electromyography were consistent with chronic proximal MCN neuropathy (right). In cases of arm wasting without pain or numbness, MCN injury should be included in the differential diagnosis, even in the presence of good power of the elbow flexors. The importance of detailed history-taking and clinical correlation cannot be over-emphasized in such cases.

Short-term outcome of unicortical, intramedullary repair of distal biceps ruptures – A retrospective cohort study

Modern distal biceps reconstruction techniques generally have satisfactory outcomes, but are not without complications. Posterior interosseous nerve (PIN) palsy is a rare but potentially devastating complication of bicortical metal button fixation. Recently, a unicortical, intramedullary, repair technique utilizing a suture anchor has been described. The primary aim of this study was to compare short-term functional and patient-reported outcomes and complication rates in patients receiving unicortical intramedullary repair (UR) with suture anchor against those receiving bicortical repair (BR) with metallic button. We hypothesized that UR would have equally satisfactory outcomes without the complication profile. Retrospective chart review was conducted for all patients undergoing operative fixation of distal biceps tendon ruptures from 2015 to 2021 at our tertiary referral center. Twenty patients received BR, and eight patients received UR. Patient demographics and surgical complications were compared. QuickDASH scores at two-month and latest in-person and telehealth postoperative visits, as well as elbow and forearm range of motion at last clinical visit, were collected and analyzed. Average patient age in the BR & UR cohorts were 49.3±9.3 and 42.1±6.2 years, respectively, with a male predominance. There was no statistical difference in patient age, sex, hand dominance, injury laterality, injury chronicity, and follow-up duration. Range of motion was comparable and excellent in both groups. Latest follow-up was 3.0±0.5 years in the BR and 1.5±0.4 years in the UR cohorts. QuickDASH scores improved between the two-month and latest time points in each cohort however did not differ significantly in head-to-head comparison. Complications included a case of PIN palsy, distal biceps tendon rerupture, and lateral antebrachial cutaneous nerve (LABC) neuropraxia in the BR group and two cases of LABC neuropraxia in the UR group. The number needed to treat (NNT) for the prevention of one additional case of PIN palsy using UR is 22 patients. Short-term functional and patient-reported outcomes in traditional BR and newly reported UR of distal biceps tendon ruptures are comparable and excellent. UR did not have higher failure rate despite follow-up periods beyond what is typically reported for tendon reruptures. In this limited retrospective cohort study, UR also did not encounter postoperative PIN palsy and had an NNT of 22 patients. In the appropriate clinical setting, this provides early evidence supporting the utilization of unicortical intramedullary suture anchor fixation of distal biceps tendon ruptures as well as associated perioperative interventions such as preoperative nerve blocks.

The relationship between the lateral cutaneous antebrachial nerve and the superficial branch of the radial nerve and its impact on regional anesthetic and pain blocks of the thumb; What is more important: Nerves or dermatomes?

BackgroundInnervation of the thumb and radial part of the dorsum of the hand is achieved primarily by the radial nerve, which is usually blocked for hand surgery. Inefficient blocks occur because the lateral antebrachial cutaneous nerve also extends into this area. The question then arises, whether skin innervation and peripheral blocking techniques should be directed at from the innervation by these nerves or more by the dermatome and its spinal segments. MethodsIn 68 human upper limbs embalmed with Thiel’s method, the topography of the lateral antebrachial cutaneous nerve (LACN), the superficial branch of the radial nerve (sbRN) and communicating branch (CB) were investigated by meticulous dissection from the cubital fossa to the most distal macroscopically dissectible branch, and the areas reached by these nerves were compared to the described dermatome. ResultsIn 52.9% of all specimens, the LACN was found proximal to the rascetta, in 35.3% it extended to the base of the thumb, and in 8 cases (11.8%) it extended distally to the base of the thumb. In 50%, the LACN was anterolateral to the brachioradialis muscle, and in 38.2%, strictly lateral. Only in 8 cases (11.8%) the LACN presented itself running more dorsally and laterally. A CB was observed in 28 specimens (41.2%). Both investigated nerves were found to innervate the dermatomes of C6 and C7. ConclusionsThe LACN should be considered for individual targeted blocks for surgical procedures and pain therapy within the wrist and thumb region as all nerves that might contribute to innervation of a targeted dermatome should be blocked.

Anatomic study of an anterior portal for percutaneous internal fixation of capitellum fractures.

Fractures of the capitellum are uncommon and difficult to treat surgically. Capitellar open reduction-internal fixation uses a lateral open approach with posterior-to-anterior or anterior-to-posterior screw fixation. We investigated the use of an anterior portal for placement of anterior-to-posterior screw fixation through cadaveric measurement of the anatomic relationships from an anteriorly to posteriorly placed Kirschner wire (K-wire) to anterior elbow structures and calculated the percentage of articular surface accessed from the anterior portal. Eight fresh-frozen cadaveric elbows without radiographic or cutaneous evidence of prior trauma or surgery were used for this study. An arthroscopic proximal anteromedial portal was cannulized, and the radiocapitellar joint was evaluated. A single 1-cm portal was placed 1 cm distal to the elbow flexion crease and based lateral to the biceps tendon. The location of the portal was confirmed with a spinal needle, and blunt dissection with a hemostat was performed down to capsular tissue and for arthrotomy. A spinal needle sheath was threaded over a blunt switching stick and served as a cannula for placement of a 0.062 K-wire. Articular mapping was performed with cartilage scraping by the K-wire; the K-wire was then placed at the perceived center along the proximal-to-distal and radial-to-ulnar axis of the capitellum. Fluoroscopic confirmation of the wire's location was performed. Under loupe magnification, anatomic dissection was performed and the shortest distance measurements were recorded with digital calipers from the K-wire to the dissected structures. Capitellar articular measurements were recorded, in addition to the articular area defined by the K-wire. Data analysis was performed, and the average distance and standard deviation (in millimeters) were calculated. For structures that were pierced by or touching the K-wire, the distance was recorded as 0.1 mm. The average distance from the K-wire to the radial, lateral antebrachial cutaneous, and median nerves was 1.8 mm, 11.5 mm, and 28.0 mm, respectively. The average distance from the median cubital vein and biceps tendon was 3.7 mm and 13.4 mm, respectively. The pin track pierced the brachioradialis and supinator muscles in all but 1 specimen. The average capitellar articular surface marked was 39.1% of the calculated articular footprint of the capitellum. The anterior portal to the capitellum is directly adjacent to the radial nerve and lateral antebrachial cutaneous nerve, where each is susceptible to injury. We recommend blunt dissection and insertion of a cannula to allow drilling and placement of internal fixation in a relatively safe manner with respect to neurovascular structures.

Surgical Treatment Strategies for Injuries of the "Unforgiving" Superficial Branch of the Radial Nerve.

Neuropathic pain caused by adhesions or neuroma formation of the superficial branch of the radial nerve (SBRN) is difficult to treat. The authors evaluated the effectiveness of different routinely used surgical techniques for SBRN neuralgia to provide a basis for future studies on SBRN neuralgia and explored the prognostic value of a preoperative diagnostic nerve block. The authors performed a retrospective cohort study by reviewing surgical records for procedures to treat SBRN neuralgia. Patient satisfaction was scored as satisfied or unsatisfied, and pain intensity was scored with a numeric rating scale. The authors included 71 patients who had 105 surgeries on the SBRN. Patients with a neuroma ( n = 43) were most satisfied after proximal denervation with burying into the brachioradialis muscle compared with burying elsewhere (53 versus 0 percent; p < 0.001). Adhesions of the SBRN ( n = 28) were treated with neurolysis (39 percent satisfied). If neurolysis or denervation did not suffice, an additional denervation of the lateral antebrachial cutaneous nerve or posterior interosseous nerve led to satisfaction in 38 percent. A decrease of less than 3.5 points on the numeric rating scale score after diagnostic nerve block led to higher postoperative pain scores (4.0 versus 7.5; p = 0.014). The authors found that the outcome of the diagnostic nerve block can predict the outcome of SBRN denervation and burying into brachioradialis muscle. The most effective burying technique is burying the SBRN into the brachioradialis muscle. Future studies on the treatment of SBRN neuralgia should therefore compare newer techniques, with burying the SBRN into the brachioradialis muscle as the control group.

Anatomical Study of the Innervation of Triangular Fibrocartilage Complex and Distal Radioulnar and Radiocarpal Joints: Implications for Denervation

Open and percutaneous denervation is an emerging technique for joint pain. This study investigated the course and distribution of the articular branches innervating the triangular fibrocartilage complex (TFCC), distal radioulnar joint (DRUJ), and radiocarpal joint (RCJ) relative to bony and soft tissue landmarks to guide wrist denervation procedures. Fourteen formalin-embalmed specimens were serially dissected to expose the origin, course, and distribution of articular branches innervating the TFCC, DRUJ, and RCJ. Bony and soft tissue landmarks to localize each articular branch were documented and visualized on a 3-dimensional reconstruction of the bones of the distal forearm and hand. The TFCC was innervated by articular branches from the posterior interosseus nerve (10 of 14 specimens), dorsal cutaneous branch of the ulnar nerve (14 of 14 specimens), palmar cutaneous branch of the ulnar nerve (12 of 14 specimens), and medial antebrachial cutaneous nerve (9 of 14 specimens). The DRUJ was innervated by the posterior interosseus nerve (9 of 14 specimens) and anterior interosseus nerve (14 of 14 specimens). The RCJ was innervated by the posterior interosseus nerve (14 of 14 specimens), superficial branch of the radial nerve (5 of 14 specimens), lateral antebrachial cutaneous nerve (14 of 14 specimens), and palmar cutaneous branch of the median nerve (10 of 14 specimens). Multiple nerves were found to innervate the TFCC, DRUJ, and RCJ. The relationship of anatomical landmarks to specific articular branches supplying the TFCC, DRUJ, and RCJ can inform selective denervation procedures based on the structural origin of pain. The detailed documentation of the spatial relationship of the nerve supply to the wrist provides clinicians with the anatomical basis to optimize current, and develop new denervation protocols to manage chronic wrist pain.

Primary Repair of Chronic Distal Biceps Tendon Tears.

This study reports the clinical results following primary repair of distal biceps tendon ruptures more 6 weeks after injury. A retrospective review of distal biceps tendon repairs performed by 8 different hand surgeons from January 1, 2015 to October 15, 2020 was performed. Patients with complete tears surgically treated ≥6 weeks after injury without tendon graft were included. Thirty patients qualified and underwent chart review for complication and range of motion (ROM) data. They were contacted for final patient-reported outcome measures (PROMs) using Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) and Patient Reported Elbow Evaluation (PREE) scores. Final PROMs were obtained from 21 patients with an average follow-up of 31.3 months (range: 4-71 months). Average time from injury to repair was 71 days (range: 42-204). The average QuickDASH score was 6.6 (±6.2) and PREE score was 7.8 (±8.0). The amount of elbow flexion necessary to complete the repair was documented in 21 patients and averaged 64º (±10º). Postoperatively, patients achieved an average extension/flexion of 1º (±1º) to 138º (±2º) and pronation/supination of 76º (±4º) to 77º (±3º). Complications were reported in 14 patients (47%) and included 2 re-ruptures, 1 adhesive scar formation, 1 superficial infection, 1 intraoperative lateral antebrachial cutaneous nerve laceration, 12 neuropraxias, and 1 case of heterotopic ossification (HO). Primary repair of chronic distal biceps tendon tears greater than 6 weeks from injury demonstrated excellent PROMs and elbow ROM. However, the complication rate may be higher than early repair.

Double-Incision Technique for the Treatment of Distal Biceps Tendon Rupture.

A longitudinal antecubital incision of 3 to 4 cm allows dissection to identify and isolate the lateral antebrachial cutaneous nerve (LABCN). Supination of the forearm protects the posterior interosseus nerve, which often cannot be visualized. The distal portion of the distal biceps should be carefully identified and exposed. A high-resistance nonresorbable suture is sewn with use of a Krackow technique to whipstitch the distal 4 cm of the tendon. Alternatively, 2 sutures (4 strands) can be utilized. A curved forceps is placed in the interosseous space to identify the location for the second 4-cm incision, on the dorsal proximal forearm over the tip of the forceps with the forearm pronated. The radial tuberosity is exposed by bluntly separating the common extensor tendons, followed by transection of the supinator fibers. Two drill holes are made 5 mm apart from one another for suture passage. The tendon is passed across a loop of wire, from the anterior to the posterior incision. With the elbow at 90° of flexion and full pronation, the tendon is docked into the trough and the sutures are tied. Alternatively, the surgical repair of the distal biceps tendon rupture can be performed through a single anterior approach4. The exposure starts with a curved longitudinal antecubital incision, exploiting the interval between the brachioradialis and pronator teres with radial (lateral) retraction of the brachioradialis and medial retraction of the pronator teres. A single anterior incision allows repair through the use of various types of fixation devices, such as suture anchors, cortical buttons, and interference screws, but seems to carry an increased risk of neurological complications, especially in terms of paresthesias in the distribution of the LABCN. Nonoperative treatment might be acceptable for elderly patients with poor functional demands. The double-incision technique with bone-tunnel fixation provides good fixation strength with an expected low rate of neurological complications1. This approach offers a useful treatment option for young and active patients with physically demanding lifestyles. The double-incision technique is an effective and safe procedure to restore elbow functionality in patients with distal biceps tendon rupture. A meta-analysis1,4-16 revealed no significant differences in postoperative functional scores following procedures performed via the single-incision compared with double-incision approach. Although the differences were smaller than the minimal clinically important difference17, the single-incision technique yielded significantly greater flexion (mean ± standard deviation, 136° ± 13°) and pronation range of motion (79° ± 10°) compared with the double-incision technique (133° ± 13° and 75° ± 14°, respectively) at 2 years postoperatively. No differences in extension and supination were observed. Rates of heterotopic ossification ranged from 0.5% to 11% for the single-incision approach and from 1% to 21.4% for the double-incision approach, with significant differences favoring the single-incision technique, although in the majority of cases the heterotopic ossification was an incidental finding. Neurological complications were found in 24.5% and 13.4% cases for the single- and double-incision techniques, respectively, with a significant difference favoring the double-incision technique. When damage to specific nerves was evaluated, the double-incision technique was associated with significantly less risk of LABCN damage. One or 2 high-resistance nonresorbable sutures are sewn with use of a Krackow technique to whipstitch the distal 4 cm of the biceps tendon.A curved forceps is placed in the interosseous space to identify the location for the second incision, on the dorsal proximal forearm over the tip of the forceps.Pronation of the forearm protects the posterior interosseus nerve, which often cannot be visualized during volar dissection and bone fixation.Positioning the tendon more posteriorly on the radial tuberosity allows for optimal biomechanical function. ROM = range of motionCR = conventional radiologyMRI = magnetic resonance imagingUS = ultrasoundLABC = lateral antebrachial cutaneousPIN = posterior interosseous nerveHO = heterotopic ossificationCI = confidence intervalSI = single incisionDI = double incision.

Lateral Antebrachial Cutaneous Neuropathy: A Review of 15 Cases.

Background: Lateral antebrachial cutaneous nerve is a terminal sensory branch of the musculocutaneous nerve. Lateral antebrachial cutaneous neuropathy (LABCN) is rare and often underdiagnosed. Less than 100 cases have been described in the orthopedic literature.Methods: It’s a single-center retrospective study. A retrospective chart review of patients with LABCN who were seen over 16 years was performed. Demographics and detailed clinical information were recorded. In addition, electrodiagnostic data were reviewed, and clinical outcome was recorded.Results: Fifteen patients were included in this study. Postsurgical etiology was the most common (n = 7) cause of LABCN. Other cases included antecubital fossa phlebotomy and intravenous placement (n = 4), trauma (n = 1), overuse or repetitive forearm use (n = 2), and dog bite (n = 1). No etiology was found in one case, but the patient had diabetes.Conclusion: Our study proposes that patient positioning during orthopedic surgeries leading to stretch or compression of the lateral antebrachial cutaneous nerve is the most likely cause of LABCN. Antecubital fossa needle placement is the second most common cause of LABCN. However, it’s a rare mononeuropathy and can be underdiagnosed. Therefore, detailed history, examination, and nerve conduction studies of the bilateral lateral antebrachial cutaneous nerve could help establish the diagnosis after other etiologies have been carefully excluded.

Triceps and cutaneous radial nerve branches investigated via an axillary anterior arm approach: new findings in a fresh-cadaver anatomical study.

The authors sought to describe the anatomy of the radial nerve and its branches when exposed through an axillary anterior arm approach. Bilateral upper limbs of 10 fresh cadavers were dissected after dyed latex was injected into the axillary artery. Via the anterior arm approach, all triceps muscle heads could be dissected and individualized. The radial nerve overlaid the latissimus dorsi tendon, bounded by the axillar artery on its superior surface, then passed around the humerus, together with the lower lateral arm and posterior antebrachial cutaneous nerve, between the lateral and medial heads of the triceps. No triceps motor branch accompanied the radial nerve's trajectory. Over the latissimus dorsi tendon, an antero-inferior bundle, containing all radial nerve branches to the triceps, was consistently observed. In the majority of the dissections, a single branch to the long head and dual innervations for the lateral and medial heads were observed. The triceps long and proximal lateral head branches entered the triceps muscle close to the latissimus dorsi tendon. The second branch to the lateral head stemmed from the triceps lower head motor branch. The triceps medial head was innervated by the upper medial head motor branch, which followed the ulnar nerve to enter the medial head on its anterior surface. The distal branch to the triceps medial head also originated near the distal border of the latissimus dorsi tendon. After a short trajectory, a branch went out that penetrated the medial head on its posterior surface. The triceps lower medial head motor branch ended in the anconeus muscle, after traveling inside the triceps medial head. The lower lateral arm and posterior antebrachial cutaneous nerve followed the radial nerve within the torsion canal. The lower lateral brachial cutaneous nerve innervated the skin over the biceps, while the posterior antebrachial cutaneous nerve innervated the skin over the lateral epicondyle and posterior surface of the forearm. The average numbers of myelinated fibers were 926 in the long and 439 in the upper lateral head and 658 in the upper and 1137 in the lower medial head motor branches. The new understanding of radial nerve anatomy delineated in this study should aid surgeons during reconstructive surgery to treat upper-limb paralysis.

Ultrasound of Small Nerves.

Nerve ultrasound has become an integral part of the diagnostic workup of peripheral neuropathies. Especially in the examination of small nerves, ultrasound provides superior image quality by using high frequency transducers. For a selection of small nerves, this article summarizes the local anatomy and common pathologies and offers simple instructions for determining their location with ultrasound including some cases with pathologies. This selection of nerves comprises the great auricular nerve, the supraclavicular nerves, the suprascapular nerve, the medial antebrachial cutaneous nerve, the lateral antebrachial cutaneous nerve, the palmar cutaneous branch of the median nerve, the long thoracic nerve, the intercostobrachial nerve, the posterior cutaneous nerve, the infrapatellar branch of the saphenous nerve, the medial calcaneal nerve, and the deep peroneal nerve at the ankle. Following our recommendations, these nerves can be swiftly located and tracked along their course to the site of the pathology.

Clinical outcomes after refixation of subacute repaired distal biceps tendon ruptures

BackgroundThe aim of this study was to evaluate the clinical outcome and complication spectrum after delayed repair surgery of distal biceps tendon ruptures, postulating that satisfactory results are possible contrary to previous literature.MethodsForty-three of 92 patients with a full workup (= OPT in) undergoing primary distal biceps tendon repair were included in this study. The mean age of participants was 49.5 years (range = 22-66 years). This cohort was divided into two groups: patients undergoing acute repair (<21 days = AR group) and a group with delayed intervention (>21 days = SR group). Beside clinical evaluation, functional scores and detection of heterotopic ossification were documented. Strength of flexion and supination were measured using a BIODEX multipoint system. In addition, thirty-one patients were included only in the evaluation of complications in the absence of consent for clinical examination (= OPT out).ResultsConcerning the OPT-in group, twenty-eight patients (ø age = 48.9 years; 22-63 years) received acute repair after an average of 9.2 ± 3.7 days. On the contrary, 15 patients (ø age = 50.5 years; 32-66 years) were treated with a delay after an average of 31.4 ± 10.4 days. Regarding patient-reported outcome measures, conflicting results emerge (AR/SR: Subjective Elbow Value = 87/80%, P > .05; Mayo score = 96/93 pts, P > .05; the Disabilities of the Arm, Shoulder and Hand score = 6/13 pts, P < .05; and Oxford Elbow Score = 44/39 pts, P < .05). The main complication is the paresthesia of the lateral antebrachial cutaneous nerve, which occurs more in the group of delayed repair (AR: 21.0%, SR 31.8%). Forty-one percentage of patients in the SR group described pain in the elbow with exertion in contrast to 17.3% in the AR group. In terms of elbow strength, no significant difference in the AR or SR group compared with the contralateral side could be observed.ConclusionThe data suggest that delayed repair of distal biceps ruptures beyond 3 weeks may result in satisfactory clinical outcomes. However, exertional pain and paresthesia of the lateral antebrachial cutaneous nerve may diminish results.

Surgical Results of Chronic Distal Biceps Ruptures: A Systematic Review.

Background:Distal biceps tendon tears can cause weakness and fatigue with activities requiring elbow flexion and supination. Surgical management of chronic tears (>21 days) is not well described in the literature.Purpose:To determine the clinical outcomes of chronic distal biceps repairs and reconstructions.Study Design:Systematic review; Level of evidence, 4.Methods:We performed a search of Medline (PubMed and Ovid), EMBASE, CINAHL physical therapy, Cochrane Database of Systematic Reviews and Central Register of Controlled Trials, and PubMed Central from inception until September 29, 2020, to identify articles on chronic distal biceps ruptures. The inclusion criteria were studies with at least 1 outcome measure and 10 patients with chronic distal biceps ruptures treated surgically. The quality of the included studies was assessed with the methodological index for nonrandomized studies (MINORS) score. Functional outcomes and complications were reviewed.Results:A total of 12 studies were included after systematic database screenings. The MINORS scores ranged from 5 to 19. There were a total of 1704 distal biceps ruptures, of which 1270 were acute and 434 were chronic. Average follow-up time was 12 months to 5.1 years. Single-incision (n = 3), 2-incision (n = 2), or both (n = 6) surgical techniques were used in these studies. Four studies described the use of autografts, and 4 articles used allografts in the chronic repair. Range of motion, function, and strength outcomes were similar when compared with the contralateral arm. Pain was reduced to minimal levels. Main postoperative complications were of paresthesia (specifically to the lateral antebrachial cutaneous nerve), which were temporary in 69.1% of cases.Conclusion:The results of this review indicate that surgical management of chronic distal biceps ruptures demonstrates improvement in outcomes including pain reduction and functional ability. Although there may be a slightly higher immediate complication rate, the functional outcomes remain comparable with those seen in the patient population with acute distal biceps.

Anatomical variations in the sensory innervation of the dorsal surface of the first digit space, a cadaveric study with clinical consequences

IntroductionRadial nerve palsy is a classical complication of a humeral shaft fracture. In clinical practice, motor palsy of the radial nerve is sometimes observed without an abnormality felt in the sensory territory. HypothesisWe hypothesised that this dissociation between sensory and motor involvement is related to anatomical variations of the sensory innervation of the dorsal surface of the first digit space, thus, we decided to study the nature and frequency of these variations. Material and methodA cadaveric study was conducted on 24 upper limbs to analyse the truncal origin of the sensory branches innervating the dorsal surface of the first digit space. ResultsThe sensory branch of the radial nerve (SBRN) participated in the innervation of the dorsal surface of the first digit space in 22 limbs, an anatomical variation was present in 2 cases with a mixed innervation by the SBRN and the lateral cutaneous nerve of forearm (LCNF) in 1 case and singular innervation by LCNF, with no SBRN involvement, in 1 case. Communications between SBRN and LCNF were found in 7 cases. DiscussionPure motor radial damage, without a sensory deficit of the dorsal surface of the first digit space, does not preclude a complete traumatic injury of the radial nerve. The sensory innervation of this region can be relayed by a branch of the LCNF. Level of evidenceIV; cadaveric study.

Normative electrophysiologic reference values for the lateral and medial antebrachial cutaneous nerves among adult Sudanese population

Nerve conduction studies (NCS) help in assessing peripheral nerve injuries by localizing focal lesions, defining severity, and distinguish axonal from demyelinating disorders. Objective: To obtain electrophysiological normative values for the lateral and medial antebrachial cutaneous nerves (LACN and MACN) among healthy adult Sudanese populations.