Musculocutaneous Research Articles

An Anatomical Study of the Feasibility of the Pectoralis Minor Transfer for Subscapular Deficiency: An Investigation of the Association Between the Transferred Muscle and the Musculocutaneous and Axillary Nerves

An Anatomical Study of the Feasibility of the Pectoralis Minor Transfer for Subscapular Deficiency: An Investigation of the Association Between the Transferred Muscle and the Musculocutaneous and Axillary Nerves

Ultrasound-guided proximal radial, ulnar, median and musculocutaneous (RUMM) nerve block in rabbit (Oryctolagus cuniculus) cadavers: medial vs lateral approach

Ultrasound-guided proximal radial, ulnar, median and musculocutaneous (RUMM) nerve block in rabbit (Oryctolagus cuniculus) cadavers: medial vs lateral approach

Determining the degree of proximal nerve fascicle rotation in healthy controls using ultrahigh-frequency neuromuscular ultrasound: A pilot study.

Ultrahigh-frequency ultrasound (UHFUS) allows improved visualization and higher resolution images of nerve fascicles than standard high-frequency ultrasound. Dynamic UHFUS may detect the presence of fascicular entwinement, the recently described sonographic phenomenon of pathologic fascicular rotation seen in neuralgic amyotrophy. This pilot study aims to establish normative reference values and degrees of fascicular rotation for the proximal portions of commonly involved upper limb nerves in healthy controls using UHFUS. Twenty healthy participants underwent sonographic examination of the median, musculocutaneous, and radial nerves on both upper limbs using UHFUS with a 48 MHz linear transducer. A single rater assessed the degree of fascicular rotation in each peripheral nerve. Fascicular rotation appears to occur in the proximal portion of each of these nerves. The mean degree of fascicular rotation for each of the measured nerves was median 94.5°, musculocutaneous 97.9°, and radial 50.9°. The maximum observed fascicular rotation in each nerve was 180°. Age, sex, height, weight, body mass index, and race did not predict degree of fascicular rotation (all p > .103). A single-factor ANOVA test showed the degree of fascicular rotation differed in median, musculocutaneous, and radial nerves (F = 4.748, p = .011). UHFUS allows quantification of fascicular rotation in healthy controls in the median, musculocutaneous, and radial nerves, and provides normative data. The data from this pilot study may serve as control data for future comparative studies in conditions where fascicular rotation occurs, such as neuralgic amyotrophy.

Acute irreducible anterior shoulder dislocation due to interposition of the subscapularis muscle and the lesser tuberosity: a case report.

Efforts to reduce an anterior shoulder dislocation can fail due to numerous mechanical obstructions caused by soft tissue interposition (long head of the biceps, rotator cuff muscles, labrum, musculocutaneous nerve) and/or bony elements (displaced fragment of a greater tuberosity or glenoid fracture, bone impaction such as a Hill-Sachs lesion fixed on the glenoid rim, a bony Bankart lesion). Herein, we report the case of a 35-year-old man who sustained an anterior shoulder fracture-dislocation of his left shoulder after a fall. Despite a postreduction radiological examination that appeared misleadingly reassuring, subtle signs of persistent subluxation raised concerns. A computed tomography (CT) scan revealed subscapularis muscle entrapment along with avulsion of its bony insertion from the lesser tuberosity of the humerus, and a comminuted avulsion fracture of the greater tuberosity of the humerus. The patient underwent surgery using a deltopectoral approach. This involved releasing the entrapped subscapularis muscle and fixing the two fractured fragments. The lesser tuberosity was reduced and secured with two cannulated screws, and the comminuted fragment of the greater tuberosity was reattached using transosseous sutures. At 12-month follow-up, the patient achieved a Constant-Murley score of 85 of 100, with limitation in internal rotation at L3 but no signs of instability or new dislocation episode. This case underscores the importance of confirming shoulder reduction on at least two orthogonal views and paying close attention to the patient's feedback about sensation in their shoulder. Additionally, it highlights the utility of CT or magnetic resonance imaging scans if doubt exists about the integrity of the reduction.

Outcome of End to Side Nerve Modified Double Oberlin Procedure and End to End Dorsal Approach Spinal Accessory to Suprascapular Nerve in Partial Postganglionic BPI: A Case Report

Introduction: Brachial plexus injury (BPI) is a devastating peripheral nerve injury that mostly affecting young men, often due to motor vehicle accidents. BPIs can be classified into preganglionic and postganglionic lesions, with postganglionic injuries allowing potential nerve regeneration. The Oberlin method, aimed at reinnervating the biceps, and the Mackinnon technique, targeting both biceps and brachialis muscles, have shown promising outcomes in BPI management. Case report: A 45-year-old man presented with right hand weakness and occasional tingling in the upper arm and fingers two months after a motorcycle accident. Motor examination revealed muscle strength of 0/5 in the right trapezius, rhomboids, serratus anterior (positive winging scapula), pectoralis minor and major, latissimus dorsi, deltoid, biceps, and elbow flexion. Wrist and finger functions remained intact. Diagnosed with post-ganglionic BPI, the patient underwent two nerve transfer surgeries: the Mackinnon technique, transferring the spinal accessory nerve to the suprascapular nerve to reinnervate shoulder muscles, and the Double Oberlin procedure, transferring fascicles from the median and ulnar nerves to the musculocutaneous nerve for reinnervation of the biceps and brachialis muscles. Post-surgery, the patient engaged in an aggressive rehabilitation program focusing on strength, range of motion, and sensory re-education. Over nine months, the patient showed significant improvement in elbow flexion (MRC grade 3), wrist extension (MRC grade 5), hand grip strength (MRC grade 3) with improved sensation across the affected limb. He returned to work and daily activities with mild residual weakness and sensory deficits. Discussion: This case illustrates the effectiveness of the Mackinnon and Double Oberlin nerve transfer techniques in restoring function in a patient with total post-ganglionic BPI. The Mackinnon technique enabled shoulder muscle reinnervation, essential for abduction and stabilization, while the Double Oberlin procedure enhanced elbow flexion by reinnervating both the biceps and brachialis muscles. The combined surgical and intensive rehabilitation approach facilitated significant functional recovery. Conclusion: The successful application of the Double Oberlin and Mackinnon techniques in this case demonstrates their potential in managing total post-ganglionic BPI. Early surgical intervention and consistent rehabilitation are crucial for optimizing recovery outcomes. This case highlights the importance of a multidisciplinary approach in treating complex peripheral nerve injuries. Keywords: Double Oberlin, Mackinnon, Brachial Plexus Injury

Modified medial approach for the treatment of fractures of the lower third of the humeral shaft: An anatomical study

BackgroundThe anatomical study of the modified medial approach for addressing fractures of the distal third of the humeral shaft aimed to elucidate the benefits of this method in providing optimal exposure for surgical intervention. MethodsSixteen upper limb specimens from eight cadavers, obtained from the Anatomy Teaching Department of Fujian Medical University, were dissected. Three-dimensional anatomical structures were mapped onto a two-dimensional coordinate system. Key anatomical structures relevant to the modified medial approach, including the medial cutaneous nerve, musculocutaneous nerve, ulnar nerve, basilic vein, brachial artery, superior ulnar collateral artery, and inferior ulnar collateral artery, were documented in detail. ResultsThe average humeral shaft length measured (29.22 ± 2.78) cm, with its medial surface being flat and well-suited for plate fixation. The basilic vein, located superficially in the upper arm's first quadrant, measured (1.35 ± 0.35) cm from the most prominent point of the medial epicondyle of the humerus, with the deep fascia being penetrated at (12.41 ± 1.71) cm. The basilic vein serves as a key landmark for the modified medial approach. The nervi cutanei antebrachii medialis, running along the medial biceps humerus, closely accompanies the basilic vein, perforating the deep fascia above the medial epicondyle and extending anterior external and posterior medial branches. These branches are positioned (0.80 ± 0.17) cm and (0.45 ± 0.29) cm, respectively, from the basilic vein. Additionally, all nervi cutanei antebrachii medialis pass anteriorly to the basilic vein before continuing distally to the forearm. The ulnar nerve initially accompanies the basilic vein in the upper arm but diverges posteriorly without branching at (14.75 ± 1.74) cm, with the maximum separation from the basilic vein measuring (2.28 ± 0.59) cm. The brachial artery bifurcates into the superior and inferior ulnar collateral arteries along the humeral shaft. The superior collateral ulnar artery primarily supplies the ulnar nerve, positioned (14.14 ± 1.27) cm from the medial epicondyle, which ensures a sufficient blood supply for operative procedures. The musculocutaneous nerve and radial nerve branch are located in the lateral region of the brachial muscle, with minimal postoperative impact on muscle strength when splitting the brachial muscle by one-third. ConclusionsThe modified medial approach, as revealed by anatomical studies, focuses on the fracture site with a straight skin incision aligned between the most prominent point of the medial epicondyle and the midpoint of the axilla, positioned one transverse finger from the radial side. Using the basilic vein as a reference, major vessels and nerves remain undisturbed, ensuring a safe operative zone. This technique allows for significant exposure of both the anterior and external humeral shaft fracture site and the ulnar side butterfly fragment while minimizing tissue damage and facilitating rapid recovery. The approach offers notable clinical value due to its reduced invasiveness and accelerated postoperative rehabilitation.

Estimation of the muscle force by perineural intramuscular electrical stimulation in healthy volunteers.

The present study aimed to evaluate the elbow flexor force induced by perineural intramuscular stimulation compared with surface electrical stimulation (ES) and maximal voluntary contraction. Thirty nondominant arms of healthy volunteers were evaluated. Isometric elbow flexion force was evaluated using a surface electrode stimulation at the biceps brachii muscle, a perineural intramuscular stimulation around the musculocutaneous nerve, and maximum voluntary contraction. The elbow flexion force was measured at the wrist volar area in a 90° elbow flexion posture, fixed with a rigid elbow orthosis. Pain and discomfort associated with ES were evaluated using a numeric rating scale. The mean maximum elbow flexion force was 16.6 ± 4.1 kgf via voluntary contraction. The mean elbow flexion force by ES was 2.9 ± 2.0 kgf, stimulation intensity was 24.8 ± 5.5 mA, and the numeric rating scale was 5.0 ± 2.5 via surface electrode stimulation and 3.1 ± 2.0 kgf, 5.0 mA, and 3.8 ± 1.9 via perineural stimulation, respectively. ES provides 16% to 18% of the maximal voluntary contraction force in elbow flexion, which corresponds to a fair grade of muscle force. Perineural intramuscular stimulation can generate an equivocal contraction force with less discomfort in elbow flexion than surface electrode stimulation.

A Retrospective Study of Lateral Antebrachial Cutaneous Nerve Neuropathy: Electrodiagnostic Findings and Etiologies in 49 Cases.

The lateral antebrachial cutaneous nerve (LACN) is the terminal sensory branch of the musculocutaneous nerve and is rarely entrapped or injured. This study describes the electrodiagnostic (EDX) findings and etiologies of LACN neuropathy. This is a review of 49 patients with pain and/or paresthesia of the forearm who underwent EDX studies. The diagnosis of LACN neuropathy was based on clinical and sensory conduction abnormalities. The most common etiology of LACN neuropathy was iatrogenic injury in 30 (61.2%) patients, primarily due to biceps tendon repair at the elbow (11 [36.7%]) and phlebotomy (5 [16.7%]). Fifteen (30.6%) patients sustained a non-iatrogenic injury at the proximal forearm/elbow, consisting of six (60%) laceration injuries and five (33.3%) stretch injuries. Four (8.2%) patients comprised the "other" etiology category, including two mass lesions causing LACN compression. Pain, paresthesia, and/or numbness in the LACN distribution were reported in 33 (67.3%), 27 (55.1%), and 23 (46.9%) patients, respectively. Hypoesthesia was detected in 45 (91.8%) patients, and dysesthesia in 7 (14.3%). The sensory nerve action potentials (SNAPs) of the LACN on the symptomatic side were absent in 44 (89.8%) patients. Of the five patients whose SNAPs of the LACN were detected, all had a decreased amplitude, and two had increased sensory latency. The most common etiology for LACN neuropathy in this series was iatrogenic injury; repair of biceps tendon at the elbow was the most frequent provoking cause. Protection of the LACN during surgical procedures at the elbow and forearm is vital to prevent iatrogenic injury.

A double communication branch between musculocutaneous and median nerves: first case report, anatomical study, and comprehensive review of clinical implications.

According to the literature, the brachial plexus presents a high rate of anatomical variations in the human neural system. The musculocutaneous nerve, a vital component of the brachial plexus, exhibits significant anatomical variations that hold clinical relevance across multiple medical disciplines. This case report, with a comprehensive review, explores the different variations in the course, branching patterns, and clinical implications of the musculocutaneous nerve. Understanding these variations is essential for surgeons, radiologists, and clinicians to enhance surgical precision, improve diagnostic accuracy, and reduce the risk of iatrogenic complications. During an anatomical dissection we observed a very rare anatomical variation of the musculocutaneous nerve. Based on this discovery, we performed research in the literature with the aim of finding if this variation has been previously described. Firstly, we identified various classifications of anatomical variations of communicating branches between the musculocutaneous and median nerves, and then we observed that these variations corresponded to various rates of frequency. Our finding is a rare undescribed anatomical variant within the variants classified as Type II according to Le Minor, which is observed in 6.8-10.7% of cases. The peculiar position of anatomical variations and anastomosis has clinical and functional relevance. Healthcare professionals must be aware of these variations to minimize surgical complications, accurately diagnose neurovascular pathologies, and optimize patient management. Further research into the genetic and embryological underpinnings of these variations may provide additional insights into this intriguing aspect of human anatomy.

Pulsed electromagnetic fields attenuate human musculocutaneous nerve damage induced by biceps eccentric contractions.

Pulsed electromagnetic field (PEMF) therapy, a noninvasive treatment, has shown promise in mitigating nerve damage. However, unaccustomed exercises, such as eccentric contractions (ECCs), can damage both muscle and nerve tissue. This study investigated whether magnetic stimulation (MS) with PEMF could aid in nerve recovery after ECCs in the elbow flexors. Twenty participants were randomly assigned to either a control (CNT) or an MS group. Following ECCs, we measured the latency of the M-wave in the musculocutaneous nerve as an indicator of nerve function. Additionally, isometric torque, range of motion, and muscle pain were assessed for muscle function. Interestingly, only the CNT group exhibited a significant increase in latency on Day 2 (p < 0.05). The MS group, on the other hand, displayed an earlier recovery trend in isometric torque, range of motion, and muscle soreness. Notably, muscle soreness significantly decreased immediately after MS treatment compared to pretreatment levels. These findings suggest that MS treatment can effectively attenuate nerve damage induced by ECCs exercise.

Analysis of artificial intelligence medical treatment for closed muscle skin nerve injury caused by aerobics training

In aerobics training, closed myocutaneous nerve damage needs to be paid attention to, especially high-intensity training may cause minor damage to muscles and nerves. With the help of AI medical technology and the understanding of molecular and cellular biomechanics, we can more accurately explore the mechanism of injury, such as the effects of nerve tensile stress and microenvironment changes on nerve regeneration. This helps to develop scientific rehabilitation methods, such as AI-assisted personalized training, neural regeneration technology, and real-time monitoring of training intensity to speed up athletes’ rehabilitation and reduce the risk of future injuries. Purpose: Aerobics training is very strict and requires high physical fitness of dancers. During long-term training, dancers can easily cause closed musculocutaneous nerve injury. Traditional medicine is difficult to guarantee the treatment effect of patients with musculocutaneous nerve injury. The use of artificial intelligence medicine for closed musculocutaneous nerve injury treatment can improve the treatment effect of aerobics training induced closed musculocutaneous nerve injury. Method: This article utilized artificial intelligence medicine for the treatment of musculocutaneous nerve injury, and used artificial intelligence technology to analyze patient imaging and other data to assist doctors in accurate diagnosis. Utilize intelligent algorithms to predict medication plans, reduce medication errors, and intelligently adjust the course of treatment based on the patient’s condition. In artificial intelligence healthcare, high-quality online medical services can be created through intelligent technology, providing convenient medical consultation for patients. Result: This article selected 200 patients with musculocutaneous nerve injury caused by aerobics training for grouping experiments. The average diagnostic accuracy of traditional medicine and artificial intelligence medicine were 84.2% and 95.6%, respectively. Conclusion: Artificial intelligence medicine can achieve medical informatization and intelligently analyze patients’ medical information, which helps to improve the accuracy of medical diagnosis for aerobics training injuries.

Revisiting the Muscles and Nerves of Anterior Compartment of the Arm: A Case Report.

During routine dissection of the anterior compartment of the arm region, we encountered several variations in the muscular and neural structures in the right upper extremity of a female cadaver. We observed one superiorly positioned extramuscular head with fibers originating from both the biceps brachii (BB) and coracobrachialis (CB) muscles and one inferiorly positioned extramuscular head with fibers solely from the BB muscle. The musculocutaneous nerve did not penetrate the CB muscle, but instead provided a muscular branch that communicated with the median nerve (MN). Both the MN and brachial artery (BA) flow beneath the extra head. This case suggests that the described variations may contribute to the entrapment of the MN and compression of the BA. Understanding these variations is crucial before surgical intervention. The failure to recognize such anatomical nuances could lead to inadvertent nerve injury or compromised vascular perfusion, emphasizing the need for preoperative planning and intraoperative vigilance.

Variations of musculocutaneous nerve – A cadaveric study

Background: Musculocutaneous nerve (MCN) is a mixed nerve arising from the lateral cord of brachial plexus having root values C5, 6, and 7. It supplies the muscles of the flexor compartment of the arm namely; coracobrachialis, most part of brachialis and both heads of biceps brachii. It is cutaneous to the lower lateral part of forearm. Variations in the origin, course, branching pattern, termination, and connections of MCN are very common. Knowledge about these variations is important while evaluating unusual presentations of peripheral nerve injuries, during surgical procedures such as arthroscopy of shoulder joint, corrections of fracture humerus, brachial plexus block, and so on. Aims and Objectives: The study was conducted to find out any variations in the origin, course, branching pattern of the MCN. The secondary objective was to understand about the communication of the MCN with any other nerve. Materials and Methods: A descriptive study was conducted in 60 upper limb specimens dissected from 10% formalin embalmed 30 cadavers (adult) in the Department of Anatomy, Government Medical College, Kottayam. All limbs were carefully dissected and studied about the origin, course, termination, and variations of MCN. Results: Out of 60 specimens studied, in 46 specimens MCN Originate from lateral cord, eight from medial cord, and in six from the lateral root of the median nerve (MN). In 52 specimens, MCN supplies coracobrachialis but only in 34 it pierces this muscle. In four specimens, there is a communication between MCN and MN was seen. Conclusion: The MCN has significant variations and knowledge of these variations is clinically important in diagnosis and management of peripheral nerve injuries as well as surgical interventions in the arm.

Unusual Multiple and Bilateral Combinations of Arterial and Neural Variations in the Axillae of Single Cadaver

Nerve During the dissection of the axillae and upper limbs of an 80-year-old male donor, multiple vascular and neural variations were encountered. On the right side, the thoracoacromial artery and the lateral thoracic artery were absent. On the left side the subscapular artery was absent, and the posterior cord of the brachial plexus gave branch to two upper subscapular nerves and then divided into radial nerve and a common stem that branched into thoracodorsal nerve, lower subscapular nerve, nerves to teres major and minor muscles and the axillary nerve. Additionally, in the left arm there was a variant communication between the musculocutaneous nerve and the median nerve. Although the existence of these variations is well documented in the literature as individual entities or few combinations, the occurrence of such multiple variations in a single cadaver in a limited area of the body involving vessel and nerves is not common. A multitude of variations in a small area of the body such as this can be a source of diagnostic and imaging interpretation errors. Unpredictable iatrogenic injuries can also occur during various procedures in the area such as during preparation of muscle flap, mastectomy with axillary lymph node dissection, reconstructive and aesthetic plastic surgery of the breast and other clinical procedures including shoulder arthroplasty.

An Unusual Third Root of the Median Nerve from the Musculocutaneous Nerve: A Case Report

Nerve variations in the brachial plexus, particularly the median nerve, are clinically significant due to their implications in surgeries and nerve compression syndromes. This case report details an anatomical variation observed during the routine dissection of a 72-year-old male cadaver. A third root of the median nerve originating from the musculocutaneous nerve was found in the right upper limb. This finding aligns with previous studies on brachial plexus variations and underscores their importance in surgical planning and nerve repair procedures. Knowledge of such anomalies is crucial for preventing iatrogenic injuries and improving outcomes in reconstructive surgeries. Keywords: Prosection; Brachial plexus; Median nerve; Musculocutaneous nerve

Restoration of coherent reach-grasp-pull movement via sequential intraneural peripheral nerve stimulation in rats

Objective. Peripheral nerve stimulation (PNS) has been demonstrated as an effective way to selectively activate muscles and to produce fine hand movements. However, sequential multi-joint upper limb movements, which are critical for paralysis rehabilitation, has not been tested with PNS. Here, we aimed to restore multiple upper limb joint movements through an intraneural interface with a single electrode, achieving coherent reach-grasp-pull movement tasks through sequential stimulation. Approach. A transverse intrafascicular multichannel electrode was implanted under the axilla of the rat’s upper limb, traversing the musculocutaneous, radial, median, and ulnar nerves. Intramuscular electrodes were implanted into the biceps brachii (BB), triceps brachii (TB), flexor carpi radialis (FCR), and extensor carpi radialis (ECR) muscles to record electromyographic (EMG) activity and video recordings were used to capture the kinematics of elbow, wrist, and digit joints. Charge-balanced biphasic pulses were applied to different channels to recruit distinct upper limb muscles, with concurrent recording of EMG signals and joint kinematics to assess the efficacy of the stimulation. Finally, a sequential stimulation protocol was employed by generating coordinated pulses in different channels. Main results. BB, TB, FCR and ECR muscles were selectively activated and various upper limb movements, including elbow flexion, elbow extension, wrist flexion, wrist extension, digit flexion, and digit extension, were reliably generated. The modulation effects of stimulation parameters, including pulse width, amplitude, and frequency, on induced joint movements were investigated and reach-grasp-pull movement was elicited by sequential stimulation. Significance. Our results demonstrated the feasibility of sequential intraneural stimulation for functional multi-joint movement restoration, providing a new approach for clinical rehabilitation in paralyzed patients.

Positive effect of ulnar nerve fascicle transfer to musculocutaneous nerve seeded with allogeneic adipose tissue derived stem cells on nerve regeneration for repairing upper brachial plexus injury in a rat model: A preliminary study.

Traumatic peripheral nerve injury, with an annual incidence reported to be approximately 13-23 per 100,000 people, is a serious clinical condition that can often lead to significant functional impairment and permanent disability. Although nerve transfer has become increasingly popular in the treatment of brachial plexus injuries, satisfactory results cannot be obtained even with total nerve root transfer, especially after serious injuries. To overcome this problem, we hypothesize that the application of stem cells in conjunction with nerve transfer procedures may be a viable alternative to more aggressive treatments that do not result in adequate improvement. Similarly, some preliminary studies have shown that adipose stem cells combined with acellular nerve allograft provide promising results in the repair of brachial plexus injury. The purpose of this study was to assess the efficacy of combining adipose-derived stem cells with nerve transfer procedure in a rat brachial plexus injury model. Twenty female Wistar rats weighing 300-350 g and aged 8-10 weeks were randomly divided into two groups: a nerve transfer group (NT group) and a nerve transfer combined adipose stem cell group (NT and ASC group). The upper brachial plexus injury model was established by gently avulsing the C5-C6 roots from the spinal cord with microforceps. A nerve transfer from the ulnar nerve to the musculocutaneous nerve (Oberlin procedure) was performed with or without seeded allogeneic adipose tissue-derived stem cells. Adipose tissue-derived stem cells at a rate of 2 × 106 cells were injected locally to the surface of the nerve transfer area with a 23-gauge needle. Immunohistochemistry (S100 and PGP 9.5 antibodies) and electrophysiological data were used to evaluate the effect of nerve repair 12 weeks after surgery. The mean latency was significantly longer in the NT group (2.0 ± 0.0 ms, 95% CI: 1.96-2.06) than in the NT and ASC group (1.7 ± 0.0 ms, 95% CI: 1.7-1.7) (p < .001). The mean peak value was higher in the NT group (1.7 ± 0.0 mV, 95% CI: 1.7-1.7) than in the NT and ASC group (1.7 ± 0.3 mV, 95% CI: 1.6-1.9) with no significant difference (p = .61). Although S100 and PGP 9.5 positive areas were observed in higher amounts in the NT and ASC group compared to the NT group, the differences were not statistically significant (p = .26 and .08, respectively). This study conducted on rats provides preliminary evidence that adipose-derived stem cells may have a positive effect on nerve transfer for the treatment of brachial plexus injury. Further studies with larger sample sizes and longer follow-up periods are needed to confirm these findings.

The Outcome of Spinal Accessory Nerve Transfer to the Musculocutaneous Nerve in Birth Brachial Plexus Palsy

Patients with brachial plexus birth injury with limited intraplexal donors require the use of extraplexal donors. Concern regarding the potential for respiratory problems resulting from the harvest of intercostal nerves or the phrenic nerve suggests the need for other options. Transfer of the spinal accessory nerve (SAN) is one option for restoring elbow flexion in adult patients; however, there are few reports of the results of this transfer in brachial plexus birth injury. This study aimed to report the result of SAN transfer to the musculocutaneous nerve (MCN) in brachial plexus birth injury. Patients who had undergone SAN to MCN nerve transfer were included in thisstudy. Patients were classified according to Narakas classification. The chart was reviewed for the time for recovery of elbow flexion according to the Active Movement Scale(AMS). Eleven patients underwent SAN to MCN transfers with interpositional sural nerve grafts. Mean birthweight was 4,070 grams (range: 3,300-4,670). Mean time to operation was 6.5 months (range: 4-10). Of the 11 patients, two were of Narakas type 3, whereas the others were of type 4. One patient did not recover elbow flexion and underwent later tendon transfer, whereas the other 10 patients reached AMS grade M6 recovery. The median time for AMS grade M1 elbow flexion recovery was eight months (interquartile range: 6.2-8.8) and for AMS grade M5 was 26 months (interquartile range: 14.2-36.5). Spinal accessory nerve to MCN transfer with an interposition nerve graft is a viable option for restoring elbow flexion. However, long-term outcomes of this procedure have yet to be fully demonstrated. Case series IV.

Brachial Plexus Injury Influences Efferent Transmission on More than Just the Symptomatic Side, as Verified with Clinical Neurophysiology Methods Using Magnetic and Electrical Stimulation.

The variety of sources of brachial plexus injuries (BPIs) and the severity and similarity of their clinical symptoms with those of other injuries make their differential diagnosis difficult. Enriching their diagnosis with objective high-sensitivity diagnostics such as clinical neurophysiology may lead to satisfactory treatment results, and magnetic stimulation (MEP) might be an advantageous addition to the diagnostic standard of electrical stimulation used in electroneurography (ENG). The asymptomatic side in BPI cases sometimes shows only subclinical neurological deficits; this study aimed to clarify the validity and utility of using MEP vs. ENG to detect neural conduction abnormalities. Twenty patients with a BPI and twenty healthy volunteers with matching demographic and anthropometric characteristics were stimulated at their Erb's point in order to record the potentials evoked using magnetic and electrical stimuli to evaluate their peripheral motor neural transmission in their axillar, musculocutaneous, radial, and ulnar nerves. MEP was also used to verify the neural transmission in participants' cervical roots following transvertebral stimulations, checking the compatibility and repeatability of the evoked potential recordings. The clinical assessment resulted in an average muscle strength of 3-1 (with a mean of 2.2), analgesia that mainly manifested in the C5-C7 spinal dermatomes, and a pain evaluation of 6-4 (mean of 5.4) on the symptomatic side using the Visual Analog Scale, with no pathological symptoms on the contralateral side. A comparison of the recorded potentials evoked with magnetic versus electrical stimuli revealed that the MEP amplitudes were usually higher, at p = 0.04-0.03, in most of the healthy volunteers' recorded muscles than in those of the group of BPI patients, whose recordings showed that their CMAP and MEP amplitude values were lower on their more symptomatic than asymptomatic sides, at p = 0.04-0.009. In recordings following musculocutaneous and radial nerve electrical stimulation and ulnar nerve magnetic stimulation at Erb's point, the values of the latencies were also longer on the patient's asymptomatic side compared to those in the control group. The above outcomes prove the mixed axonal and demyelination natures of brachial plexus injuries. They indicate that different types of traumatic BPIs also involve the clinically asymptomatic side. Cases with predominantly median nerve lesions were detected in sensory nerve conduction studies (SNCSs). In 16 patients, electromyography revealed neurogenic damage to the deltoid and biceps muscles, with an active denervation process at work. The predominance of C5 and C6 brachial plexus injuries in the cervical root and upper/middle trunk of patients with BPI has been confirmed. A probable explanation for the bilateral symptoms of dysfunction detected via clinical neurophysiology methods in the examined BPI patients, who showed primarily unilateral damage, maybe the reaction of their internal neural spinal center's organization. Even when subclinical, this may explain the poor BPI treatment outcomes that sometimes occur following long-term physical therapy or surgical treatment.

Surgical accidents and postoperative complications of recurrent shoulder dislocation treated by suture button fixation with bone occlusion

To summarize the surgical accidents and postoperative complications of the treatment of recurrent shoulder dislocation by suture button fixation and bone occlusion, and to provide clinical reference. The clinical data of 16 patients with recurrent shoulder dislocation treated with modified arthroscopic Latarjet suture button fixation and bone occlusion between July 2017 and April 2023 were retrospectively analyzed. Among them, 15 were male and 1 was female. The age ranged from 16 to 45 years, with an average of 26 years. Admission examination showed the range of motion of shoulder joint was normal; the shoulder joint fear test was positive; En-face CT scan measured 10%-20% of the glenoid defects, averaging 13.4%; and MRI examination revealed bone Bankart injury. The disease duration ranged from 2 to 20 years, with an average of 7.1 years. The shoulder joint was dislocated 8- 45 times, with an average of 17.4 times, and the shoulder joint was unstable. The occurrence of surgical accidents and postoperative complications as well as corresponding measures and outcomes were recorded. All the incisions healed by first intention without any complications such as incision infection or vascular injury. All 16 cases were followed up for an average of 3.6 years (range, 1-7 years), and no shoulder redislocation occurred. Four types of intraoperative surgical accidents and two types of postoperative complications occurred in the early stage of implementation of the technique. Intraoperative surgical accidents included 1 case of difficulty in passing subscapular muscle through coracotomy with large size, which was treated with exchange rod or finger through subscapular muscle split; 2 cases of coracoidal process fracture, of which 1 case was treated conservatively, and the other case was sutured to the base of tendon and fixed through tunnel; 1 case of glenoid fracture occurred in the glenoid tunnel, which was fixed with knot-free anchors; the posterior loop plate fixation was abnormal in 2 cases, of which 1 case was re-fixed and the other case was renovated. Postoperative complications included coracoid bone mass displacement in 1 case, conservative biceps rehabilitation was given to avoid premature external rotation; 1 case of radial nerve injury of healthy upper limb and musculocutaneous nerve injury of affected side was given oral medication and physiotherapy. The above conditions recovered well after corresponding treatment. Suture button fixation with bone occlusion is a safe method for the treatment of recurrent shoulder dislocation. Careful operation should be performed during coracoid interception and glenoid tunnel drilling, especially in the fixation process.