Musculocutaneous Research Articles

Safety and effectiveness of thermal radiofrequency applied to the musculocutaneous nerve for patients with spasticity.

Evaluate safety and effectiveness of thermal radiofrequency in the musculocutaneous nerve in patients with focal elbow flexor spasticity. Ambispective observational follow-up study. Patients with focal spasticity secondary to central nervous system injury with elbow flexor pattern who received thermal radiofrequency treatment in the musculocutaneous nerve between 2021 and 2023 were included. 12 patients. Ultrasound-guided thermal radiofrequency was applied to the musculocutaneous nerve at 80°C for 90 s. Effectiveness was assessed prior to thermal radiofrequency and at 6 months using scales to measure pain (VAS), spasticity (MAS), disability (DAS), quality of life (SQol-6D), patient-perceived and physician-perceived satisfaction (PIG-C, PGA), and goal attainment (GAS). Elbow joint range of motion was evaluated via goniometry. Safety was evaluated by assessing side effects. Patients had statistically significant improvements in spasticity (p = 0.003), severe elbow flexion (p = 0.02), pain (p = 0.046), functioning (p < 0.05), and spasticity-related quality of life (p < 0.05 in three sections). Furthermore, treatment goals were attained. Patient- and physician-perceived clinical improvement was achieved. Regarding side effects, two patients had dysesthesia that was self-limiting, with maximum duration of 1 month. Thermal radiofrequency in the musculocutaneous nerve can be a safe, effective treatment for patients with severe spasticity with an elbow flexor pattern.

Anatomical variations of the brachial plexus in adult cadavers: A descriptive study and clinical significance.

Brachial plexus injury is recognized as one of the most severe clinical challenges due to the complex anatomical configuration of the brachial plexus and its propensity for variation, which complicates safe clinical interventions. This study aimed to ascertain the prevalence and characterize the types of brachial plexus variations, and to elucidate their clinical implications. We conducted meticulous dissections of 60 formalin-fixed cadavers' upper arm, axilla and lower neck to reveal and assess the roots, trunks, divisions, cords, and branches of the brachial plexus. The pattern of branching was noted by groups of dissecting medical students and confirmed by the senior anatomists. The variations discovered were record and photographed using a digital camera for further analysis. Variations in the brachial plexus were identified in 40 of the 60 cadavers, yielding a prevalence rate of 66.7%. These variations were classified into root anomalies (2.1%), trunk anomalies (8.5%), division anomalies (2.1%), and cord anomalies (4.3%). Notably, anomalies in communicating branches were observed in 39 cadavers (83.0%): 14 with bilateral anomalies, 14 with anomalies on the left side, and 11 on the right side. These communicating branches formed connections between the roots and other segments, including trunks, cords, and terminal nerves, and involved the median, musculocutaneous, and ulnar nerves. The frequency and diversity of brachial plexus variations, particularly in communicating branches, are significant in cadavers. It is imperative that these variations are carefully considered during the diagnostic process, treatment planning, and prior to procedures such as supraclavicular brachial plexus blocks and nerve transfers, to mitigate the risk of iatrogenic complications.

Outcomes of complete neurotomy and immediate repair of the musculocutaneous nerve for treatment of elbow spasticity.

Neurotomy interrupts the stretch reflex and can be used for the treatment of spasticity. We hypothesized that neurotomy with nerve repair reduces spasticity while preserving motor function due to the preferential recovery of efferent over afferent fibres. This study reports the 1-year outcomes of neurotomy and immediate repair of the musculocutaneous nerve in the proximal arm for treatment of elbow flexor spasticity, comparing these to outcomes in the literature for neurectomy without nerve repair. A total of 10 adult patients with spasticity of the elbow flexors from stroke or traumatic brain injury who had undergone neurotomy and immediate repair of the musculocutaneous nerve were prospectively studied. The results suggest that this procedure effectively reduces elbow flexor spasticity, improves elbow resting position, active elbow extension and is useful for achieving patient goals with effects lasting at least 12 months.Level of evidence: IV (therapeutic).

Elbow Flexor Release Combined With Selective Neurectomy of Musculocutaneous Nerve for Spastic Elbow Flexion Deformity in Children and Adolescents.

Spasticity of the elbow flexors causes a dynamic and/or static elbow flexion deformity. This position interferes with the functional use of the hand, is aesthetically unpleasant and can cause problems with hygiene and comfort. A lengthening procedure of elbow flexor muscles can improve elbow posture and range of motion. However, causal spasticity is not addressed directly. Selective neurectomy of the musculocutaneous nerve has a direct effect on underlying spasticity but is not sufficient when contracture is present. In this study, we examine the long-term results of a combined surgical approach: a release procedure of the elbow flexors and selective neurectomy of the musculocutaneous nerve. A retrospective study of 14 patients with spastic flexion deformity of the elbow was performed. After a mean follow-up of 52.6 months (SD 33, range 12 to 113), the results of the combined surgical approach were evaluated. Spontaneous position of the elbow and active and passive range of motion were assesses using goniometry. Spasticity was assessed using the Modified Ashworth Scale. Function of the affected upper limb before and after surgery was assessed by the House functional classification. Patient and caretaker's satisfaction were assessed using a visual analogue scale. The mean decrease of passive elbow extension deficit was 34 degrees (SD 21.3, P <0.05). Active elbow extension increased with a mean of 41 degrees (SD 16.5, P <0.05). Spontaneous position elbow flexion decreased by a mean of 40 degrees (SD 21.1, P <0.05).The Modified Ashworth score decreased significantly ( P <0.05) from 3.27 (range 1 to 4) preoperatively to 0.64 (range 0 to 4) postoperatively.The difference between the House score preoperatively and postoperatively was not significant ( P =0.180). Mean patient satisfaction was 8.2/10 (SD 2.7, range 2 to 10) and mean caregiver satisfaction was 7.1/10 (SD 2.7, range 1 to 10). A combined surgical approach to elbow flexion deformity in the form of a lengthening procedure and selective neurectomy of the elbow flexors result in a significant and sustained improvement of the spontaneous position, active and passive elbow extension and elbow flexor spasticity and high patient and caregiver satisfaction. Case series, level IV.

Morphological classification, anatomical variations, innervation patterns, musculocutaneous nerve relation of the coracobrachialis muscle: anatomical study and clinical significance.

The anatomical variations of coracobrachialis muscle (CBM) are of great clinical importance. This study aimed to elucidate the morphological variations, innervation patterns and musculocutaneous nerve (MCN) relation to CBM. Upper limbs of fifty cadavers (30 males and 20 females) were examined for proximal and distal attachments, innervation pattern of CBM and its relation to MCN. Four morphological types of CBM were identified according to number of its heads. The commonest type was the two-headed (63.0%) followed by the single belly (22.0%), three-headed (12.0%) and lastly fourheaded (3.0%) type. Moreover, an abnormal insertion of CBM was observed in four left limbs (4.0%); one inserting into the medial humeral epicondyle, the second into the upper third of humeral shaft, the third one in the common tendon of biceps, and the fourth one showing a bifurcated insertion. Also, four different innervation patterns of CBM were identified including MCN (80.0%), lateral cord (14.0%), lateral root of median nerve (4.0%), and median nerve itself (2.0%). The course of MCN was superficial to the single belly CBM (19.0%) and in-between the heads in the other types (71.0%). Measurements of the length and original distance of CBM muscular branches originating from MCN revealed no sex or side significant difference. Awareness of the anatomic variations, innervation patterns, and MCN relation of CBM is imperative in recent diagnostic and surgical procedures to obtain definite diagnosis, effective management and good outcome.

Optimizing donor fascicle selection in Oberlin's procedure: A retrospective review of anatomical variability using intraoperative neuromonitoring.

Transfer of the fascicle carrying the flexor carpi ulnaris (FCU) branch of the ulnar nerve (UN) to the biceps/brachialis muscle branch of the musculocutaneous nerve (Oberlin's procedure), is a mainstay technique for elbow flexion restoration in patients with upper brachial plexus injury. Despite its widespread use, there are few studies regarding the anatomic location of the donor fascicle for Oberlin's procedure. Our report aims to analyze the anatomical variability of this fascicle within the UN, while obtaining quantifiable, objective data with intraoperative neuromonitoring (IONM) for donor fascicle selection. We performed a retrospective review of patients at our institution who underwent an Oberlin's procedure from September 2019 to July 2023. We used IONM for donor fascicle selection (greatest FCU muscle and least intrinsic hand muscle activation). We prospectively obtained demographic and electrophysiological data, as well as anatomical location of donor fascicles and post-surgical morbidities. Surgeon's perception of FCU/intrinsic muscle contraction was compared to objective muscle amplitude during IONM. Eight patients were included, with a mean age of 30.5 years and an injury-to-surgery interval of 4 months. Donor fascicle was located anterior in two cases, posterior in two, radial in two and ulnar in two patients. Correlation between surgeon's perception and IONM findings were consistent in six (75%) cases. No long term motor or sensory deficits were registered. Fascicle anatomy within the UN at the proximal arm is highly variable. The use of IONM can aid in optimizing donor fascicle selection for Oberlin's procedure.

455 Distal Nerve Transfers in Treatment of Peripheral Nerve Lesions

INTRODUCTION: Distal nerve transfers can be used in treating patients with irreparable high nerve lesions, aiming to regain hand function. The indications for these transfers include upper (C5-C6) and lower (C8-T1) brachial plexus palsy, isolated proximal extensive radial, median, or ulnar nerve lesion, or isolated axillary or musculocutaneous nerve lesion. METHODS: The selected cases (n = 5) included lower brachial plexus injury (n = 2), and isolated radial (n = 1), ulnar (n = 1), and median (n = 1) nerve injuries. The MRC grading was used to examine postoperative muscle strength. The DASH and PNSQoL questionnaires were used to assess the postoperative quality of life. RESULTS: The useful functional recovery (MRC = 4-5) was achieved in all presented cases. The DASH and PNSQoL scores indicated a satisfying quality of life in terms of the absence of postoperative disability. CONCLUSIONS: Distal nerve transfers are a valuable technique for treatment of the patients with irreparable proximal nerve lesions. This technique reduces the path necessary for the regenerative nerve fibers to pass, provides direct nerve coaptation without additional suture line, and facilitates faster and better recovery, with the final outcome as an increase in the patients’ quality of life.

Diabetic Neuropathy and Minimum Effective Anesthetic Concentration of Mepivacaine for Axillary Brachial Plexus Block: A Prospective Observational Study.

Nerves in patients with diabetic neuropathy (DN) show increased susceptibility to local anesthetics, potentially requiring a decreased dose. We investigated whether the minimum effective anesthetic concentration (MEAC) of mepivacaine for successful axillary block is lower in patients with DN than in those without. This prospective observational study included patients with DN (n = 22) and without diabetes (n = 22) at a tertiary care center. Patients received an ultrasound-guided axillary block with 30 mL of mepivacaine for anesthesia. The mepivacaine concentration used in each patient was calculated using Dixon's up-and-down method. A block was considered successful if all four sensory nerves had a score of 1 or 2 within 30 min with no pain during surgery. The primary outcome was the MEAC of mepivacaine, and the secondary outcomes included the minimal nerve stimulation intensity for the musculocutaneous nerve and the occurrence of adverse events. The MEAC50 was 0.55% (95% CI 0.33-0.77%) in patients without diabetes and 0.58% (95% CI 0.39-0.77%) in patients with DN (p = 0.837). The MEAC90 was 0.98% (95% CI 0.54-1.42%) in patients without diabetes and 0.96% (95% CI 0.57-1.35%) in patients with DN (p = 0.949). The stimulation threshold for the musculocutaneous nerve was significantly different between groups (0.49 mA vs. 0.19 mA for patients with vs. without diabetes; p = 0.002). In conclusion, the MEAC of mepivacaine for a successful axillary block is not lower in patients with DN.

The 2-by-2 Inch “Key Window” in the Upper Extremity: An Anatomical Appraisal of the Accessibility and Proximity of the Major Nerves and Vessels

The brachial plexus is a network of nerves located between the neck and axilla, which receives input from C5-T1. Distally, the nerves and blood vessels that supply the arm and forearm form a medial neurovascular bundle. The purpose of this study was to illustrate that a peripheral nerve dissection via a 2×2 inch window would allow for identification and isolation of the major nerves and blood vessels that supply the arm and forearm. A right side formalin-fixed latex-injected cadaveric arm was transected at the proximal part of the axillary fold and included the scapular attachments. Step-by-step anatomical dissection was carried out and documented with three-dimensional digital imaging. A 2×2 inch window centered 2 inches distal to the axillary fold on the medial surface of the arm enabled access to the major neurovascular structures of the arm and forearm: the median nerve, ulnar nerve, medial antebrachial cutaneous nerve, radial nerve and triceps motor branches, musculocutaneous nerve and its biceps and brachialis branches and lateral antebrachial cutaneous nerve, basilic vein and brachial artery and vein, and profunda brachii artery. Our study demonstrates that the majority of the neurovascular supply in the arm and forearm can be accessed through a 2×2 inch area in the medial arm. Although this "key window" may not be entirely utilized in the operative setting, our comprehensive didactic description of peripheral nerve dissection in the cadaver laboratory can help in safer identification of complex anatomy encountered during surgical procedures.

The axillary artery high bifurcation: coexisting variants and clinical significance.

Several branching patterns of the axillary artery (AA) have been described. Unusually, the brachial artery (BA) follows a course in front of the median nerve (MN), the so-called superficial brachial artery (SBA). The SBA may result in MN entrapment. The current cadaveric report highlights a high AA bifurcation, its continuation as SBA and the coexistence of muscular, neural, and vascular asymmetric aberrations. At the right side, the coracobrachialis muscle (CB) had a single head, and the ipsilateral musculocutaneous nerve (MCN) followed a medial course. The AA was highly divided into superficial and deep stems (SAS and DAS), at the 2nd rib lower border. Between two stems, the brachial plexus (BP) lateral and medial cords were identified. The MN originated from the BP lateral cord. The SAS, continued as SBA with a tortuous course. The DAS coursed posterior to the BP medial and lateral cords and gave off the subscapular artery. A bilateral 3rd head of the biceps brachii was identified. The MN atypically originated from the BP lateral cord. At the left side, the two-headed CB was typically penetrated by the MCN. A common trunk of the circumflex humeral arteries was identified in coexistence with an interconnection of the BP lateral cord with the MN medial root. The rare coexistence of muscular, neural, and arterial variants in axillary and brachial region is emphasized, taking into consideration the AA high division and related branching pattern. Documentation of such rare vascular variants is important in aneurysm and trauma surgery, and angiography, where all therapeutic manipulations must be accurately performed due to the possibility of complications.

A bilateral four-headed brachialis muscle with a variant innervation: a cadaveric report with possible clinical implications.

Anterior compartment muscles of the arm present high morphological variability, with possible clinical significance. The current cadaveric report aims to describe a bilateral four-headed brachialis muscle (BM) with aberrant innervation. Emphasis on the embryological background and possible clinical significance are also provided. Classical upper limb dissection was performed on an 84-year-old donated male cadaver. The cadaver was donated to the Anatomy Department of the National and Kapodistrian University of Athens. On the left upper limb, the four-headed BM was supplied by the musculocutaneous and the median nerves after their interconnection. On the right upper limb, the four-headed BM received its innervation from the median nerve due to the musculocutaneous nerve absence. A bilateral muscular tunnel for the radial nerve passage was identified, between the BM accessory heads and the brachioradialis muscle. BM has clinical significance, due to its proximity to important neurovascular structures and frequent surgeries at the humerus. Hence, knowledge of these variants should keep orthopedic surgeons alert when intervening in this area. Further dissection studies with a standardized protocol are needed to elucidate the prevalence of BM aberrations and concomitant variants.

Does Steal Phenomenon Exist in Multiple Neurotization?-An Experimental Rat Study.

Nerve transfers from one common donor nerve to recipient nerves with multiple target branches can yield slower and unpredictable recovery in the target nerves. Our hypothesis is that steal phenomenon exists when multiple nerve neurotization comes from one donor nerve. In 30 Sprague-Dawley rats, the left ulnar nerve (UN) was selected as the donor nerve, and the musculocutaneous nerve (MCN) and median nerve (MN) as the recipient target nerves. The rats were separated into three groups (10 rats in each): group A, UN-to-MCN (one-target); group B, UN-to-MN (one-target); and group C, UN-to-MCN and MN (two-target). The right upper limbs were nonoperative as the control group. Outcome obtained at 20 weeks after surgery included grooming test, muscle weight, compound muscle action potential, tetanic muscle contraction force, axon counts, and retrograde labeling of the involved donor and target nerves. At 20 weeks after surgery, muscles innervated by neurotization resulted in significant worse outcomes than the control side. This was especially true in two-target neurotization in the parameter of muscle weight and forearm flexor muscle contraction force outcome when compared to one-target neurotization. Steal phenomenon does exist because flexor muscle contraction force was significantly worse during two-target neurotization. This study proves the existence of steal phenomenon in multiple target neurotization but does not significantly affect the functional results. Postoperative rehabilitative measures (including electrical stimulation, induction exercise) and patient compliance (ambition and persistence) are other crucial factors that hold equivalent importance to long-term successful recovery.

Global trends and outcomes of nerve transfers for treatment of adult brachial plexus injuries.

The presentation, management and outcomes of brachial plexus injuries are likely to be subject to regional differences across the globe. A comprehensive literature search was performed to identify relevant articles related to spinal accessory to suprascapular, intercostal to musculocutaneous, and ulnar and/or median nerve fascicle to biceps and/or brachialis motor branch nerve transfers for treatment of brachial plexus injuries. A total of 6007 individual brachial plexus injuries were described with a mean follow-up of 38 months. The specific indication for accessory to suprascapular and intercostal to musculocutaneous transfers were considerably different among regions (e.g. upper plexus vs. pan-plexal), while uniform for fascicular transfer for elbow flexion (e.g. upper plexus +/- C7). Similarly, functional recovery was highly variable for accessory to suprascapular and intercostal to musculocutaneous transfers, while British Medical Research Council grade ≥3 strength after fascicular transfer for elbow flexion was frequently obtained. Overall, differences in outcomes seem to be inherent to the specific transfer being utilized.Level of evidence: III.

Mapping Motor Neuroplasticity after Successful Surgical Brachial Plexus Reconstruction Using Navigated Transcranial Magnetic Stimulation (nTMS).

Brachial plexus reconstruction (BPR) consists of the complex surgical restoration of nerve structures. To further understand the underlying motor cortex changes and evaluate neuroplasticity after a successful surgery, we performed a navigated transcranial magnetic stimulation (nTMS) study mapping the postoperative motor representation of the formerly plegic arm. We conducted a prospective nTMS study mapping the musculocutaneous nerve as a representative, prominent target of BPR including a patient (n = 8) and a control group (n = 10). Measurements like resting motor threshold (RMT), cortical motor area location, and size were taken. Mathematical analysis was performed using MATLAB 2022, statistical analysis was performed using SPSS 26, and nTMS mapping was performed using the Nexstim NBS 5.1 system. Mapping was feasible in seven out of eight patients. Median RMT on the affected hemisphere was 41% compared to 50% on the unaffected hemisphere and they were 37% and 36% on the left and right hemispheres of the control group. The motor area location showed a relocation of bicep brachii representation at the middle precentral gyrus of the corresponding contralateral hemisphere. Motor area size was increased compared to the control group and the patient's unaffected, ipsilateral hemisphere. Understanding cortical reorganization is important for potential future treatments like therapeutic nTMS. The issue of motor neuroplasticity in patients with brachial plexus lesions is worth exploring in further studies.

The anatomical variations of median nerve in Shiraz, Iran.

The origin and distribution of median nerve varies among the different individuals. The median nerve variations in axillary region were reported by many authors previously. Understanding of these variations is especially necessary for clinicians to prevent iatrogenic nerve damage. The current work aimed to evaluate the possible anatomical variations of median nerve in the axillary region in a sample of the Iranian cadavers (Shiraz, Fars). We dissected 26 upper limbs from 13 male cadavers to investigate the different variations of median and musculocutaneous nerves according to Venieratos and Anagnostopoulou classification. In 23.07% of specimens (n=6), the medial root united with 2 lateral roots and formed the median nerve proximal to the coracobrachialis muscle. In one case, a communicating branch separated from the musculocutaneous nerve distal to the coracobrachialis and connected to the median nerve in upper arm. Our results suggest that there are anatomical variations of the median nerve in terms of its origin and its communication with the musculocutaneous nerve in the population of southern Iran. The anatomical knowledge of the median nerve variations is important for clinicians to improve patient health outcome. Theses variations of the median nerve should be considered during surgical procedures of the axillary region and nerve block of the infra clavicular part of the brachial plexus.

The third head of the biceps brachii muscle exhibiting variable shape presentation: Prevalence, variability and clinical considerations

IntroductionThe third head of the biceps brachii is the predominant variation of the arm muscles. Awareness of muscular variations is essential for the management of upper limb pathologies. Variations in the shape of the muscles are rarely explored. This study aimed to describe the prevalence and anatomical presentation of the third head of the biceps brachii muscle (origin, insertion and innervation) with an emphasis on the shape and form variations. Materials and methodsBiceps brachii of eighty-nine cadavers were examined. The presence of the third head, its origin, shape patterns, blood supply, and nerve innervation were determined and recorded. ResultsThe third head of the biceps brachii was present in 20.2 %, with a prevalence of 22.2 % in males and 18.2 % in females. Half (50 %) of these were bilateral presentations. Most (92 %) of the third head of the biceps brachii variations were flat, thin and straight in shape. All the shape variation patterns were observed in males and on the left arm. The third head originated from the humerus on its anteromedial aspect in 92 % of cases. The musculocutaneous nerve innervated the third head of the biceps brachii in 96 % of the cases, and a nerve anomaly of musculocutaneous and median nerves innervated it in a single (4 %) case. The muscular branches of the brachial artery supplied the third head of the biceps brachii in all cases. ConclusionStudies on the variation of arm muscles may assist in identifying new patterns of morphological variations like the shape of the muscle and may aid in the accurate diagnosis and management of arm pathologies.

Chapter 8 - Axillary and musculocutaneous neuropathies

This chapter covers axillary and musculocutaneous neuropathies, with a focus on clinically relevant anatomy, electrodiagnostic approaches, etiologic considerations, and management principles. Disorders of the lateral antebrachial cutaneous nerve, a derivative of the musculocutaneous nerve, are also reviewed. We emphasize the importance of objective findings, including the physical examination and electrodiagnostic evaluation in confirming the isolated involvement of each nerve which, along with the clinical history, informs etiologic considerations. Axillary and musculocutaneous neuropathies are both rare in isolation and most frequently occur in the setting of trauma. Less commonly encountered etiologies include external compression or entrapment, neoplastic involvement, or immune-mediated disorders including neuralgic amyotrophy, postsurgical inflammatory neuropathy, multifocal motor neuropathy, vasculitic neuropathy, and multifocal chronic inflammatory demyelinating polyradiculoneuropathy.

Rare median and musculocutaneous nerve fusion with intraoperative electrical confirmation: illustrative case

BACKGROUND Nerve transfer is a surgical technique in which a redundant or expendable fascicle is transferred or coapted to an injured nerve distal to the site of injury for the purpose of reinnervation. Successful nerve transfer is dependent on correct intraoperative identification of donor and recipient nerves. OBSERVATIONS An 8-year-old male was recommended for ulnar nerve fascicle to biceps branch of musculocutaneous nerve transfer to restore elbow flexion weakness after a demyelinating spinal cord injury. The biceps branch was identified approximately midway along the upper arm. Proximal musculocutaneous nerve stimulation induced hand movement and electromyography activity in the median nerve muscles. Neurolysis of the thickened proximal structure revealed fusion of the musculocutaneous and median nerves. Because of the proximity of the median and musculocutaneous nerves, median rather than ulnar nerve fascicles were used as donors for transfer. LESSONS The authors provide the first reported intraoperative finding of an anatomical variant in which the musculocutaneous nerve and median nerve were fused in the upper arm, confirmed through intraoperative electrical stimulation. Surgeons should be aware of this rare anatomical variant to ensure correct nerve identification when performing nerve transfers in the proximal upper extremity.

Brain plasticity and age after restoring elbow flexion with distal nerve transfers in neonatal brachial plexus palsy and nonneonatal traumatic brachial plexus injury using the plasticity grading scale.

Ulnar and/or median nerve fascicle to musculocutaneous nerve (MCN) transfers are used to restore elbow flexion following severe neonatal and nonneonatal brachial plexus injuries (BPIs). Restoring volitional control requires plastic changes in the brain. To date, whether the potential for plasticity is influenced by a patient's age remains unknown. Patients who had presented with a traumatic upper (C5-6 or C5-7) BPI were divided into two groups: neonatal brachial plexus palsies (NBPPs) and nonneonatal traumatic BPIs (NNBPIs). Both groups underwent ulnar or median nerve transfers to the MCN for elbow flexion restoration between January 2002 and July 2020. Only those who attained a British Medical Research Council strength rating of 4 were reviewed. The primary comparison between the two groups was the plasticity grading scale (PGS) score to determine the level of independence of elbow flexion (target) from forearm motor muscle movement (donors). The authors also assessed patient compliance with rehabilitation using a 4-point Rehabilitation Quality Scale. Bivariable and multivariable analyses were used to identify intergroup differences. In total, 66 patients were analyzed: 22 with NBPP (mean age at surgery 10 months) and 44 with NNBPI (age range at surgery 3-67 years, mean 30.2 years; mean time to surgery 7 months, p < 0.001). All NBPP patients obtained a PGS grade of 4 at the final follow-up versus just 47.7% of NNBPI patients (mean 3.27, p < 0.001). On ordinal regression analysis, after nature of the injury was excluded because of excessive collinearity with age, age was the only significant predictor of plasticity (β = -0.063, p = 0.003). Median rehabilitation compliance scores were not statistically different between the two groups. The extent of plastic changes that occur for patients to regain volitional control over elbow flexion after upper arm distal nerve transfers following BPI is influenced by patient age, with complete plastic rewiring more likely in younger patients and virtually ubiquitous in infants. Older patients should be informed that elbow flexion after an ulnar or median nerve fascicle transfer to the MCN might require simultaneous wrist flexion.

Comparison of USG-Guided Supraclavicular Brachial Plexus Block by Single-Point Versus Multiple-Point Injection Technique: A Prospective Randomized Trial.

Background This study investigated the success rate of ultrasonography (USG)-guided supraclavicular block using a single-point injection technique comparing it with multiple-point injection technique, in terms of nerve sparing, time taken to perform the procedure, time taken to onset of sensory and motor block. Materials and methods A total of 204 patients of American Society of Anesthesiologists (ASA) Status I and II, aged 18-60 years, with body mass index (BMI) ≤30 kg/m2, posted for upper limb surgeries were given USG-guided supraclavicular brachial plexus block with 15 mL of 0.5% Ropivacaine. The patients were randomly divided into group A (single-point injection) and group B (multiple-point injection), using an out-of-plane technique. Sensory and motor block was assessed for onset and maximum grade achieved, by using pinprick, cold, touch, and movement respectively. The efficacy of the block was tested by assessment in the territories of musculocutaneous, ulnar, radial, median, axillary, and intercostobrachial nerves. Procedural time was calculated from the insertion of the needle till the complete injection of the drug. Results Patients in both groups were comparable in terms of demography and ASA status. The success rate for group A was 60.8%, compared to 98% in group B. In group B, the intercostobrachial nerve was most commonly spared (7.84%), followed by ulnar (1.96%), and radial (0.98%). On the other hand, in group A, the most frequently spared nerves were ulnar and intercostobrachial (23.5% each), followed by radial (12.7%), axillary (10.8%), musculocutaneous (7.8%), and median nerves (6.9%). The onset of sensory and motor block was similar in both groups. The procedure time was longer in the multiple-point group. Conclusion Our observations suggest that nerve sparing is much lesser in the multiple-point injection technique used for USG-guided supraclavicular block. In a good number of patients using this technique, the intercostobrachial nerve gets blocked.