Medial Antebrachial Cutaneous Research Articles

The Medial Antebrachial Cutaneous Nerve Is a Low-Morbidity Alternative to the Standard Sural Nerve Autograft.

Nerve interposition grafting is an important technique in nerve reconstructive surgery that is used when a primary repair is not feasible without significant tension. This study sought to evaluate the long-term morbidity of the medial antebrachial cutaneous (MABC) nerve as an alternative donor nerve in comparison with sural nerve harvest. A single surgeon and institution retrospective chart review was performed to identify all patients who underwent nerve autografting using the sural and MABC as donor nerves between January 1, 2000 and December 31, 2019. Surveys assessed overall patient satisfaction with surgery, as well as donor and recipient site morbidity, satisfaction, pain, numbness, and cold sensitivity. Of the 73 patients contacted, 54 agreed to participate, and 43 of 73 (58.9%) ultimately completed the survey: 28 MABC (65.1%) and 15 sural (34.9%). There were no significant differences between the sural and MABC groups in overall satisfaction with surgery, donor and recipient site satisfaction, pain, cold sensitivity, and effect on quality of life. Even though 66.7% of sural donor sites and 75% of MABC donor sites had residual numbness, the effect this had on quality of life was very low (2 and 3, respectively). The MABC is a safe alternative to the traditional sural nerve autograft. A small subset of patients undergoing nerve autograft harvest will experience long-term morbidity in the form of pain. Conversely, the more common presence of numbness is not reported as bothersome.

Ulnar Nerve Decompression With Subcutaneous Transposition

Background: Medial-sided elbow injuries are becoming increasingly common among throwing athletes due to overuse and increased specialization at early ages. High valgus stress and repetitive elbow flexion/extension during throwing not only affects the ligaments and dynamic support of the elbow, but commonly affects the ulnar nerve. Indications: Management of cubital tunnel syndrome is initially rest, therapy, and functional training; however, if conservative measures do not appropriately address the ulnar neuropathy, surgical decompression with subcutaneous transposition is a reliable treatment option. Technique Description: An incision is created over the medial epicondyle. The medial antebrachial cutaneous nerve is identified and protected. The ulnar nerve is identified and tagged with a vessel loop to allow for appropriate handling of the nerve. Decompression of the ulnar nerve begins proximally by spreading the tissues superficial to the ulnar nerve and splitting the fascia overlying it. Then, dissection deep to the nerve is performed. A small strip of the medial intermuscular septum will be used as a sling to hold the nerve securely in the transposed position. This is released proximally and the distal attachment to the medial epicondyle is left in place. Decompression is then continued distally by releasing the superficial fascia over the flexor carpi ulnaris (FCU) and a portion of the deep FCU muscle belly and fascia. The nerve is decompressed circumferentially, while preserving penetrating branches to the FCU as able. Ultimately, the ulnar nerve is decompressed 10 cm proximal and 10 cm distal to the medial epicondyle. The intermuscular septum is then pulled over the nerve, checked for appropriate length, and sutured in place both posterior and anterior to the ulnar nerve. Results: Symptom improvement after decompression and transposition is high (>90%); however, performance outcomes in overhead and throwing athletes is variable, and return to previous or higher level of play ranges from 60% to 90%. Discussion/Conclusion: Ulnar nerve decompression and transposition can reliably address underlying symptoms, but results are mixed for return to sport outcomes in overhead and throwing athletes. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Fascicular shifting in the reconstruction of brachial plexus injuries: an anatomical and clinical evaluation.

Until recently, autologous sensory nerve grafting has remained the gold-standard technique in peripheral nerve reconstruction. However, there are several disadvantages to these grafts, such as donor site morbidity, limited availability, and a qualitative mismatch. Building on this shortage, a new concept, the fascicular shift procedure, was proposed and successfully demonstrated nerve regeneration in a rat nerve injury model. This approach involves harvesting a fascicular group distal to a peripheral nerve injury and shifting it to bridge the defect. The present study aimed to evaluate the clinical applicability of this technique in brachial plexus reconstruction. The supra- and infraclavicular nerves of the brachial plexus were bilaterally explored in 18 formalin-fixed cadaveric specimens. Following dissection, their fascicular shifting potential was evaluated. The medial antebrachial cutaneous and sural nerves were investigated and used as references for the required cross-sectional area of potential nerve grafts. Furthermore, 29 brachial plexus injuries, which qualified for surgical repair, were subjected to retrospective analysis. The intraoperatively measured lengths of the harvested and ultimately transplanted nerve grafts served as a basis to assess graft requirements in brachial plexus lesions. The transplanted nerve grafts measured a total length of 51.9 ± 28.1 cm in brachial plexus injuries. The individual inserted nerve grafts averaged 10.3 ± 5.1 cm. In the anatomical exploration, the ulnar and median nerves qualified for fascicular shifting. Their fascicular graft lengths measured 26.6 ± 2.5 cm and 24.8 ± 5.2 cm, respectively. The long thoracic, suprascapular, musculocutaneous, thoracodorsal, and axillary nerves were not suitable for fascicular shifting. The sensory graft length of the medial antebrachial cutaneous nerve measured 20.6 ± 3.4 cm. In the surgical reconstruction of brachial plexus injuries, fascicular shifting of the ulnar and median nerves provides sufficient donor material. Even though potential donor length is limited in the radial nerve, it may still help to expand the surgical armamentarium in selected clinical scenarios. Overall, the fascicular shift procedure presents a novel alternative to allow modality-matched grafting in the reconstruction of large proximal nerve defects and was found to be an attractive option in brachial plexus reconstruction.

A Case Report of a Rare Variation of the Medial Cutaneous Nerve of Forearm

Introduction: The brachial plexus is the largest and most complex nerve network in the body, which is formed in the neck and enters the axillary cavity after passing under the clavicle. So far, many variations have been reported in the brachial network, which are clinically important. The plexus has three cords, one of which is the medial cord. The medial cutaneous nerve of the arm and the medial cutaneous nerve of the forearm are the branches of the medial cord that innervate the skin of the medial surface of the arm and forearm, respectively. In this study, a rare variation was observed in the branches of the medial cord of the brachial plexus during the dissection of the upper limb of an approximately 80-year-old man in the Dissection Hall of Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Thus, in normal condition, there is no connection between the medial cutaneous nerve of the arm and the medial cutaneous nerve of the forearm, and each of them innervates the skin of the medial arm and forearm separately, but in this case, these two nerves are connected. And since knowing this type of variation is very important for surgeons, more studies are needed to determine its prevalence in the population.

(038) Optimizing Innervation in Radial Forearm Phalloplasty: Determination of Ideal Nerve Coaptations via Donor:Recipient Axon Ratios

Abstract Introduction There is currently no standardized approach to innervation in radial forearm phalloplasty. This includes both the number and the combination of nerve coaptations that are performed. It is also under-recognized that the nerve coaptations executed in phalloplasty are equivalent to sensory nerve transfers. It is well documented that a key component of a successful nerve transfer is a sufficient donor:recipient (D:R) axon ratio. Evidence suggests a minimum ratio of greater than 0.3:1 and an optimal ratio of greater than or equal to 0.7:1 to best optimize nerve regeneration and outcomes. Axon counts and donor:recipient axon ratios have not yet been performed for the sensory nerves used in phalloplasty surgery. Objective The purpose of this study was to obtain axon counts for the donor and recipient nerves used in radial forearm phalloplasty in order to calculate donor:recipient axon ratios for each possible sensory nerve transfer. This information will inform which nerve coaptations are most ideal in radial forearm phalloplasty based on both axon counts and donor:recipient axon ratios. Methods Following IRB approval and informed consent, five transmasculine patients who underwent gender-affirming phalloplasty at our institution had nerve specimens (5 mm) taken from five different sensory nerves that are routinely transected during surgery – the lateral antebrachial cutaneous (LABC), medial antebrachial cutaneous (MABC), posterior antebrachial cutaneous (PABC), ilioinguinal, and dorsal nerve of the clitoris. Histomorphometric evaluation was performed to determine mean axon counts for each nerve respectively. Donor:recipient axon ratios were then calculated for each possible combination of donor and recipient nerves. Results Mean axon counts for the recipient nerves were 6957 (LABC), 1866 (MABC), 1712 (PABC). Mean axon counts for the donor nerves were 2301 (ilioinguinal), and 5141 (dorsal nerve of clitoris). Calculated D:R axon ratios were as follows: clitoral:LABC 0.739, clitoral:MABC 2.754, clitoral:PABC 3.002, ilioinguinal:LABC 0.331, ilioinguinal:MABC 1.233, and ilioinguinal:PABC 1.344. Conclusions Based on both mean axon counts and D:R ratios, the clitoral nerve is the more powerful donor nerve available in phalloplasty and should be considered for use as a primary donor. All D:R ratios exceed 0.3:1. However the best matches based on D:R ratios and clinical size match appear to be clitorial:LABC and ilioingiinal:MABC or ilioinuinal:PABC. If using MABC or PABC to coapt into the clitoral nerve, there should be consideration for using only part of the clitoral nerve to prevent unnecessary levels of clitoral denervation or neuroma formation given significant excess of donor axons available compared to recipient pathways for regeneration. The ilioinguinal nerve is likely under-powered to consistently re-innervate the LABC. In general, most coaptations are highly favorable for functional levels of nerve regeneration. This also suggests additional factors beyond successful nerve regeneration may contribute to optimal sensory outcomes following phalloplasty surgery. Disclosure No

Anatomical observation and CT three-dimensional reconstruction of Five-shu acupoints of Shaoyin Heart Meridian in rabbit's forelimb

To investigate the location and anatomical structure of "Shaochong"(HT9), "Shaofu"(HT8), "Shenmen"(HT7), "Lingdao"(HT4) and "Shaohai"(HT3) in the rabbit's forelimb. Sixteen rabbits (half male and half female) were used in the present study. By referring to the national standards on the location of acupoints in the human body and the literature about the location of acupoints in the rabbit, and by using the method of comparative anatomy, the location and needling operation of the Five-shu acupoints of Shaoyin Heart Meridian on the rabbit's forelimb were defined, and these acupoints were needled and CT three-dimensional reconstruction were conducted. Then, the rabbits were killed, and intravascular perfusion was performed, followed by inserting acupuncture needles into these five acupoints for observing the anatomical relationship between the inserted acupuncture needle and the structure of surrounding tissues. HT9 is located at the medial side of the little finger of forelimb, about 1 mm beside the nail root, and is adjacent to the superficial flexor tendon of the finger, the dorsal branches of the proper palmar digital artery and vein, and the endings of dorsal branch of palmar digital proper nerve of the ulnar nerve on the fifth finger side. HT8 is located at the palm side of the forelimb, horizontally parallel to the proximal end of the 5th metacarpophalangeal joint and between the 4th and 5th metacarpal bones, and is adjacent to the lumbricalis, the 4th and 5th interossei, and common palmar digital artery and vein and the palmar digital proper nerve of the ulnar nerve. HT7 is located at the medial margin of the extensor carpal tendon on the ulnar side, between the distal end of the ulna and the ulnar carpal bone, and is adjacent to the tendons of flexor carpi ulnaris and extensor carpi ulnaris, ulnar artery, ulnar vein and ulnar nerve. HT4 is located at the medial border of the ulnar flexor tendon, about 1.5 cun superior to HT7, and is adjacent to extensor carpi ulnaris, flexor carpi ulnaris, flexor digitorum superficialis, flexor digitorum profundus, ulnar artery, vein and ulnar nerve. HT3 is located at the depression, medial to the condyle of humerus when the elbow is bent at 90°, its neighbor structure is composed of pronator teres, biceps brachii, brachial artery and vein, radial collateral artery, radial collateral vein, medial antebrachial cutaneous nerve and median nerve. In the rabbit, there is a close relationship between HT9, HT8, HT7, HT4 and HT3 regions and brachial vascular and its branches, cephalic vein and its branches, medial antebrachial cutaneous nerve, median nerve and ulnar nerve, which is the morphological basis of the Five-shu acupoints of Shaoyin Heart Meridian for treating some related clinical disorders.

Diagnostic value of proximal cutaneous nerve biopsy in brachial and lumbosacral plexus pathologies

Brachial and lumbosacral plexopathies can result from numerous non-traumatic etiologies, including those of inflammatory, autoimmune, or neoplastic origin, that often require nerve biopsy for diagnosis. The purpose of this study was to evaluate the diagnostic efficacy of medial antebrachial cutaneous nerve (MABC) and posterior femoral cutaneous nerve (PFCN) nerve biopsies in proximal brachial and lumbosacral plexus pathology. Patients undergoing MABC or PFCN nerve biopsies at a single institution were reviewed. Patient demographics, clinical diagnosis, symptom duration, intraoperative findings, post-operative complications, and pathology results were recorded. Biopsy results were classified as diagnostic, inconclusive, or negative based on the final pathology. Thirty patients undergoing MABC biopsies in the proximal arm or axilla and five patients with PFCN biopsies in the thigh or buttock were included. MABC biopsies were diagnostic in 70% of cases overall and 85% diagnostic in cases where pre-operative MRI also demonstrated abnormalities in the MABC. PFCN biopsies were diagnostic in 60% of cases overall and in 100% of patients with abnormal pre-operative MRIs. There were no biopsy-related post-operative complications in either group. In diagnosing non-traumatic etiologies of brachial and lumbosacral plexopathies, proximal biopsies of the MABC and PFCN provide high diagnostic value with low donor morbidity.

Isolated medial antebrachial cutaneous nerve injury after blunt trauma: a case report

BackgroundThe medial antebrachial cutaneous nerve is a branch of the brachial plexus that contains C8–T1 segments. Injury of this nerve by various mechanisms has been reported in the literature; however, currently, there is no reported case of medial antebrachial cutaneous nerve injury in the setting of acute blunt trauma.Case presentationThis case report presents the case of a 34-year-old Persian female with dysesthesia and pain in the medial side of the forearm immediately following a blunt trauma by mechanism of elbow external rotation. On electrodiagnostic evaluation, the medial antebrachial cutaneous nerve sensory nerve action potential of the symptomatic side had a significant amplitude drop (more than 50%), compared with the other side. On follow-up electrodiagnosis, after several sessions of physical therapy, the medial antebrachial cutaneous nerve sensory nerve action potential still had a significant amplitude difference.ConclusionBlunt trauma can be one of the causes of medial antebrachial cutaneous nerve involvement. An electrodiagnostic study can be helpful in the diagnosis of this nerve injury after blunt trauma.

Clinically Relevant Anatomical Variations in the Brachial Plexus.

Anatomical variation in the brachial plexus may result in a variety of clinically relevant patterns, including various neuralgias of the upper extremity and differing nerve territories. Some conditions can be debilitating in symptomatic patients, resulting in paresthesia, anesthesia, or weakness of the upper extremity. Others may simply result in cutaneous nerve territories that deviate from a traditional dermatome map. This study evaluated the frequency and anatomical presentations of a large number of clinically relevant brachial plexus nerve variations in a sample of human body donors. We identified a high frequency of various branching variants, of which clinicians, especially surgeons, should be aware. The medial pectoral nerves in 30% of the sample were found to originate from either the lateral cord, or both the medial and lateral cords of the brachial plexus rather than exclusively from the medial cord. The dual cord innervation pattern greatly increases the number of spinal cord levels traditionally believed to innervate the pectoralis minor muscle. The thoracodorsal nerve arose as a branch of the axillary nerve 17% of the time. The musculocutaneous nerve sent branches to the median nerve in 5% of specimens. The medial antebrachial cutaneous nerve shared a common trunk with the medial brachial cutaneous nerve in 5% of individuals and derived from the ulnar nerve in 3% of specimens.

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.

Repair of complex digital soft-tissue defects using a free composite ulnar artery perforator flap from the volar wrist.

Digital skin defects resulting from trauma are often associated with dysfunction of the digital nerve and the extensor and flexor tendons in the affected fingers. The repair of these complex tissue defects requires a graft containing multiple tissues that can be used to reconstruct the tendons and nerves and restore the skin. Such procedures can cause multiple injuries and significant damage to the donor site. The current study used a novel technique to repair complex dorsal and palmar digital soft-tissue defects. First, multiple tissues were cut and collected from the donor site. Then, part of the flexor carpi ulnaris tendon was transplanted to repair the tendon defect, and a medial antebrachial cutaneous nerve graft was used to repair the digital nerve defect. Finally, a skin flap was used to cover the skin defect. This paper reports on 31 cases of complex soft-tissue digital defects, with defect areas of 2-18 cm2 . One patient presented with a postoperative arterial crisis in the flap. All other patients recovered without experiencing a vascular crisis, flap necrosis, or wound infection. The postoperative flaps were similar in texture to the original digital skin. The sensation and the extension/flexion functions in the affected fingers recovered well. The effect on grip strength, wrist flexion, and forearm sensation was minor and the postoperative total active motion scores of the affected digits were good or excellent in 96.77% of the cases. The flap sensation recovery rate was also excellent in 83.87% of the cases. The present technique facilitates the repair of multiple dorsal and palmar digital soft-tissue, tendon and nerve defects, reduces the damage to the donor site, and significantly improves the success of surgical repair.

Use of Electroneuromyography in the Diagnosis of Neurogenic Thoracic Outlet Syndrome: A Systematic Review and Meta-Analysis.

Neurogenic thoracic outlet syndrome (NTOS) is a disabling condition. Its diagnosis remains challenging and is mainly guided by examination. Yet, electrophysiological evaluations are the gold standard for diagnosis of entrapment syndromes. We aimed to assess the interest of electrophysiological evaluation to diagnose NTOS. A systematic literature research was performed using PubMed, ScienceDirect, Embase, Cochrane and Google Scholar databases to collect studies reporting results of electrophysiological assessment of patients with NTOS. Then, a meta-analysis was conducted. Nine studies were eligible and concerned two hundred and thirteen patients. Results were heterogenous among studies and the quality of evidence was very low to moderate. Data could not evaluate sensitivity or specificity of electrophysiological evaluations for NTOS. The meta-analysis found significantly decreased amplitudes of medial antebrachial cutaneous nerve SNAP (sensory nerve action potential), ulnar SNAP, median CMAP (compound motor action potential) and ulnar CMAP. Needle examination found abnormalities for the abductor pollicis brevis, first dorsal interosseous and adductor digiti minimi. Unlike most upper-limb entrapment syndromes, nerve conduction assessment only provided clues in favour of NTOS. Decreased amplitude for ulnar SNAP, medial antebrachial cutaneous SNAP, median CMAP and ulnar CMAP should be assessed, as well as needle examination. Larger studies are needed to evaluate the sensitivity and specificity of electrophysiology in NTOS diagnosis.

Ultrasonographic Identification of the High-Risk Zone for Medial Antebrachial Cutaneous Nerve Injury in the Elbow.

ObjectiveTo demonstrate the sonoanatomy of the medial antebrachial cutaneous nerve (MACN) in the elbow region using high-resolution ultrasonography (HRUS) to identify areas at a high risk of MACN injury.MethodsA total of 44 arms were included in the study. In the supine position, the participants’ arms were abducted 45° with the elbow fully extended. The MACN was visualized in the transverse view. The anterior branch of the MACN (ABMACN), posterior branch of the MACN (PBMACN), and location of the branching sites were determined. The distance between the ABMACN and superficial veins, including the basilic vein (BV) and median cubital veins (MCV) was measured. For the PBMACN, the distance to the ulnar nerve (UN) and to BV were measured.ResultsThe MACN was subdivided into 2.18±1.00 branches, including ABMACN and PBMACN. The ABMACN and PBMACN were subdivided into 1.60±0.78 and 1.07±0.25 branches, respectively. The branching point of the MACN was 8.40±2.42 cm proximal to the interepicondylar line (IEL). We demonstrated that the ABMACN is located close to the BV and MCV in the elbow region, and the PBMACN was located approximately 1 cm and 0.8 cm anterior to the UN and posterior to the BV at the IEL level, respectively.ConclusionConsidering the location of the MACN, including ABMACN and PBMACN, clinicians can perform invasive procedures around the elbow region more carefully to lower the risk of MACN injury.

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.

A meta-analysis on the anatomical variability of the brachial plexus: Part III – Branching of the infraclavicular part

IntroductionThe anatomy of the brachial plexus has been a subject of interest to many researchers over time resulting in an inconsistent amount of data. Previously, our team had published two evidence-based studies on the anatomical variations involving the brachial plexus, therefore the aim of this study was to analyze the findings regarding the infraclavicular part of the brachial plexus with the use of meta-analytic techniques to complete the comprehensive series. Material and methodsMajor scientific databases were extensively searched to compile anatomical studies investigating the morphology of the infraclavicular part of the brachial plexus. Extracted data were classified based on our proposed classification system and subsequently analyzed with the use of random effects meta-analysis to state the pooled prevalence estimates of the distinct variation patterns. ResultsA total of 75 studies (4772 upper limbs) were selected for the meta-analysis. The branches of the lateral cord, including the lateral pectoral nerve and musculocutaneous nerve, resembled their usual origin in 76.8% (95% CI 50–96%) and 98.8% (95% CI 98–100%), respectively. The medial pectoral nerve, medial brachial cutaneous nerves, medial antebrachial cutaneous nerve and ulnar nerve emerging from the medial cord were observed originating from their usual origins in 90.9% (95% CI 68–100%), 90.7% (95% CI 73–100%), 87.9% (95% CI 67–99%) and 97.7% (95% CI 94–100%), respectively. Lastly, nerves branching from the posterior cord, including the superior and inferior subscapular nerves, thoracodorsal nerve, axillary nerve and radial nerve, originated as per textbook description in 90.7% (95% CI 80–98%), 76.1% (95% CI 61–89%), 90.1% (95% CI 84–95%), 79.8% (95% CI 68–90%) and 99.0% (95% CI 96–100%), respectively. Moreover, the usual origin of the median nerve from the lateral and medial cord via the corresponding roots was encountered in 89.7% (95% CI 84–95%) of cases. ConclusionsThe nerves originating from the infraclavicular part of the brachial plexus exhibit a wide spectrum of possible origins. However, the usual patterns were significantly the most common types present in more than three quarters of cases. Especially clinicians might profit from the enhanced understanding of the brachial plexus anatomy presented herein, since we offer a strong guide for handling the anatomically challenging pathologies in this specific area.

Outcomes of 53 thoracic outlet syndrome cases with confirmed neurological deficit

IntroductionNeurogenic thoracic outlet syndromes (TOS) are dominated by the nonspecific forms. This study focuses only on the rarer true forms related to proximal nerve compression in the thoracic outlet, with the presence of motor (atrophy of the hand's intrinsic muscles) and/or sensory (hypoesthesia in the territory of the medial antebrachial cutaneous nerve) deficits. The objectives of this study were to define the clinical characteristics, anatomical causes and surgical results of this condition. Patients and methodsSingle-center retrospective study of 53 consecutive cases in 50 patients with an objective clinical deficit confirmed by nerve conduction studies. The population consisted of 47 adults and 3 children, 9 males and 41 females, with a mean age of 39 years (9-80 years), diagnosed between July 1994 and December 2019. An objective motor deficit was present in 50 cases, with the remaining 3 having a sensory deficit only. Forty cases underwent surgery, most often via the supraclavicular approach, while 13 cases did not undergo surgery because their deficit was longstanding and non-progressive. ResultsOne operated patient was lost in follow-up. An analysis of the medical records of 18 cases, including 15 operated cases found complete recovery in 4 cases, significant improvement in 9 cases and small improvement in 2 cases at a mean follow-up of 53 months (1-162 months). Thirty-four cases were reviewed in person, including 24 operated cases and evaluated with a mean follow-up of 135 months (36-284 months): the pain had disappeared in 21 cases, thenar atrophy persisted in 17 cases, which was associated with a claw-hand deformity in 3 cases, while 2 cases had an isolated claw-hand deformity. The patients were very satisfied with the procedure in 15 cases and satisfied in 9 cases. They evaluated the benefit of surgery at 87% and their upper limb function increased from 38% (10-60%) preoperatively to 77% (60-100%) at the review. ConclusionFew studies in the literature have focused on true neurogenic TOS cases. The treatment is surgical in progressive cases; an anatomical anomaly is always present. Surgical treatment eliminates the pain and helps to stabilize or even partially resolve the deficit. Despite a moderate objective gain, the patients’ feeling of functional improvement is important with a high satisfaction rate. Level of evidenceIV, retrospective.

A Cadaveric Study of Thread Cubital Tunnel Release with Newly Developed Threads.

ObjectiveThe percutaneous thread transection technique is a surgical dissecting method using a dissecting thread inserted through a needle under ultrasound guidance without skin incision. As the new dissecting threads were developed domestically, this cadaver study was conducted to compare the effectiveness and safety between the new threads (ultra V sswire and smartwire-01) and a pre-existing commercial dissecting thread (loop & shear) by demonstrating a modified looped thread cubital tunnel release. MethodsThe percutaneous cubital tunnel release procedure was performed on 29 fresh cadaveric upper extremities. The preexisting commercial thread was used in 5 upper extremities. The two newly developed threads were used in 24 upper extremities. Two practitioners performed the procedures separately. After the modified looped thread cubital release, anatomical and histological analyses were performed by a blinded anatomist. The presence of the dissected cubital tunnel and damaged adjacent soft tissue was assessed. ResultsOut of the 29 cadaveric upper extremities, 27 specimens showed complete dissection of the Osborne ligament and the proximal fascia of the flexor carpi ulnaris muscle. One specimen was incompletely dissected in each of the ultra V sswire and smartwire-01 groups. There were no injuries of adjacent structures including the ulnar nerve, ulnar artery, medial antebrachial cutaneous nerve, or flexor tendon with either the commercial thread or the newly developed threads. The anatomical analysis revealed clear and sharp incisional margins of the cubital tunnel in the Smartwire-01 and loop & shear groups. All three kinds of threads maintained proper linear elasticity for easy handling during the procedure. The smartwire-01 provided higher visibility in ultrasound than the other threads. ConclusionThe newly developed threads were effective and safe for use in the thread cubital tunnel release procedure.

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.

Fetal topography of cubital region nerves

Background. The expansion of indications for surgical interventions on the structures of the elbow area is due to the need for a purposeful study of individual and age-related features of the innervation of the skin of the elbow region and the capsule of the elbow joint. Objective is to find out the sources of innervation of the skin of the elbow region and the articular capsule of the elbow joint in human fetuses of 4-10 months. Methods. A macromicroscopic study was carried out on preparations of the upper limbs of 26 human fetuses of 81.0-375.0 mm parietalcoccygeal length (PCL). Results. In some of the examined fetuses, a classical version of the topography of the nerves of the ulnar region was observed. General innervation of the elbow joint is possible by the articular branches of the median, ulnar and variable nerves. An atypical version of the topography of the left medial cutaneous nerve of forearm was observed in a fetus of 225.0 mm PCL, which branched into three branches: lateral, intermediate, and median. In one case (fetus 260.0 mm PCL), a connection between the right musculocutaneous nerve and the right medial cutaneous nerve of arm was detected. The left medial cutaneous nerve of arm was absent in a fetus of 170.0 mm PCL, in this case, the left median cutaneous nerve of the forearm provided sensitive innervation of the skin of the anteromedial surface of the shoulder, which may indicate compensatory development of its branches. Conclusions. Variability of the amount and sources of origin of the branches providing innervation of the capsule of the elbow joint and the skin of the elbow region has been established in human fetuses. We believe that the zone of impaired sensitivity in the case of damage to the cutaneous nerves of the shoulder and elbow areas, and areas of the forearm, as a rule, are smaller than the anatomical areas of distribution of the cutaneous nerves or their branches. It is because some areas of the skin of the elbow area support additional innervation from adjacent nerves – “overlap zones”. The described variants of individual and age-related anatomical variability of the nerves of the ulnar region in human fetuses contribute to the improvement of surgical tactics for performing reconstructive operations in case of traumatic damage to the long branches of the brachial plexus.

CLINICAL AND NEUROPHYSIOLOGICAL PARALLELS OF THE BRACHIAL PLEXOPATHY IN THE STRUCTURE OF NEUROGENIC THORACIC OUTLET SYNDROME

The aim: Was assessment of the neurophysiological data and features of clinical picture in patients with neurogenic thoracic outlet syndrome (TOS). Materials and methods: 103 patients with upper extremity pain and/or paresthesia or hypotrophy, or a combination of these symptoms were examined. The examination algorithm included: cervical spine radiography, cervical spine and brachial plexuses magnetic resonance imaging (MRI), upper extremity soft tissues and vessels ultrasonic examination, stimulation electroneuromiography with F-waves registration. Results: Neurogenic TOS was diagnosed in 29 patients. A significant relationship between the following complaints and neurophysiological parameters was observed: pain, numbness during physical activity and decreased medial anrebrachial cutaneous nerve response amplitude by ≥25% compared to the contralateral side; hypothenar hypotrophy and decrease of ulnar nerve motor/sensory response amplitude; the 4-5th fingers hypoesthesia and decrease of ulnar nerve sensory response amplitude. Conclusions: Medial antebrachial cutaneous nerve amplitudes asymmetry indices of ≥25% or lack of response may be considered to be a marker of true neurogenic TOS.