Functional outcome and histologic analysis of late onset total type brachial plexus injury treated with intercostal nerve transfer to median nerve with local umbilical cord-derived mesenchymal stem cells or secretome injection: a double-blinded, randomized control study.

INTRODUCTION: Intercostal nerve transfer is a surgical technique used to restore function in patients with total brachial plexus injury. Stem cell and secretome therapy has been explored as a potential treatment for brachial plexus injuries. This study aimed to compare the functional and histologic outcome of intercostal nerve transfer to median nerve with local stem cells or secretome injection in total type brachial plexus injuries. MATERIALS AND METHODS: This was a double-blinded, randomized controlled study (RCT). We included patients with neglected total type brachial plexus injury (BPI) who underwent nerve transfer and local injection of either umbilical cord-derived mesenchymal stem cells (UC-MSC) or secretome into median nerve-flexor digitorum superficialis (FDS) neuromuscular junction (NMJ). We measured preoperative and 8-month postoperative FDS muscle strength, SF-36, DASH score, and histologic assessment. We then analyzed the difference outcome between those two groups. RESULT: A total of 15 patients were included in this study. Our study found that after nerve transfer and implantation with either UC-MSC or secretome, significant postoperative improvements were observed in physical functioning, role limitations, energy/fatigue, emotional well-being, social functioning, pain, general health, and DASH scores, particularly in the overall cohort and the secretome group. When we compared the mean difference of clinical outcome from preoperative to postoperative between UC-MSC and secretome groups, the UC-MSC group showed better improvement of health change in SF-36 subgroup compared to secretome group. From the analysis, there was no significant difference in the histologic outcomes (inflammation, regeneration, and fibrosis) in overall cohort between preoperative and postoperative cohort. There was also no significant difference in mean change of the histologic outcomes (inflammation, regeneration, and fibrosis) preoperative and postoperatively between UC-MSC and secretome groups. DISCUSSION AND CONCLUSION: Implantation of either UC-MSC or secretome along with nerve transfer may provide clinical improvement, while to achieve histologic improvement, further conditioning should be performed.

Nerve Versus Tendon Transfers in the Management of Isolated Upper Extremity Peripheral Nerve Injuries.

Upper extremity peripheral nerve injuries present functional deficits that are amenable to management by tendon or nerve transfers. The principles of tendon and nerve transfers are discussed, with technical descriptions of preferred tendon and nerve transfers for radial, median, and ulnar nerve injuries.

Visualization of Median Nerve Entrapment After Reduction of an Elbow Fracture Dislocation Using 3-Dimensional Magnetic Resonance Imaging: A Case Report.

CASE: A 10-year-old girl presented after closed reduction of an elbow fracture dislocation. She demonstrated intact vascularity but a dense median nerve palsy. Preoperative magnetic resonance neurography (MRN) precisely mapped the median nerve entrapped within the medial epicondylar fracture. Intraoperatively, the median nerve was freed preceding reduction and fracture fixation. Postoperatively, neurological symptoms completely resolved, and she regained full elbow function. CONCLUSION: Median nerve injury can present without associated vascular injury. In this case, MRN was helpful in preoperatively illustrating the spatial relationship between the median nerve and the medial epicondyle.

Entrapment of Median Nerve After Pediatric Elbow Dislocation with a Brief Review of Literature: A Case Study.

CASE: We present a case of type II (intraosseous) entrapment of the median nerve in a patient who was diagnosed based on clinical examination and magnetic resonance imaging and who was treated with medial epicondyle osteotomy, neurolysis, and transposition of the nerve to its anatomical position within a month of injury. Our patient made a complete motor and sensory recovery at 5 months with complete functionality and grip strength. CONCLUSION: Median nerve entrapment after posterolateral elbow dislocation is a rare complication with roughly 40 cases reported in the literature. This case illustrates the importance of prompt diagnosis and treatment.

The Safety of Volar to Dorsal Percutaneous Screw Fixation of Bennett Fracture-Dislocation - A Cadaveric Study.

Background: Bennett fractures are traditionally fixed with percutaneous K-wires from dorsal to volar, or with a volar to dorsal screw via a volar open approach. While volar to dorsal screw fixation is biomechanically advantageous, an open approach requires extensive soft tissue dissection, thus increasing morbidity. This study aims to investigate the practicality and safety of Bennett fracture fixation using a percutaneous, volar to dorsal screw, particularly with regard to the median nerve and its motor branch during wire and screw insertion. Methods: Fifteen fresh frozen forearm and hand specimens were obtained from the University of Auckland human cadaver laboratory. A guidewire is placed under image intensifier from volar to dorsal with the thumb held in traction, abduction and pronation. The wire is passed through the skin volarly under image intensifier, then the median nerve is dissected from the carpal tunnel and the motor branch of the median nerve (MBMN) is dissected from its origin to where it supplies the thenar musculature. The distance between the K-wire to the MBMN is measured. Results: In 14 of 15 specimens, the wire was superficial and radial to the carpal tunnel. The mean distance to the origin of the MBMN is 6.2 mm (95% CI 4.1-8.3) with the closest specimen 1 mm away. The mean closest distance the wire gets to any part of the MBMN is 3.7 mm (95% CI 1.6-5.8); in two specimens, the wire was through the MBMN. Conclusions: Wire placement, although done under image intensifier, is subject to significant variation in exiting location. While research has shown the thenar portal in arthroscopic thumb surgery is safe, our guidewire needs to exit further ulnar to capture the Bennett fracture fragment, placing the MBMN at risk. This cadaveric study has demonstrated the proposed technique is unsafe for use.

Timing of surgery in peripheral nerve injury of the upper extremity.

Peripheral nerve injuries present a complex clinical challenge, requiring a nuanced approach in surgical management. The consequences of injury vary, with sometimes severe disability, and a risk of lifelong pain for the individual. For late management, the choice of surgical techniques available range from neurolysis and nerve grafting to tendon and nerve transfers. The choice of technique utilized demands an in-depth understanding of the anatomy, patient demographics and the time elapsed since injury for optimized outcomes. This paper focuses on injuries to the radial, median and ulnar nerves, outlining the authors' approach to these injuries.Level of evidence: IV.

Median nerve electrical stimulation improves traumatic brain injury by reducing TACR1 to inhibit nuclear factor-κB and CCL7 activation in microglia.

The existing report elucidates that median nerve electrical stimulation (MNS) plays a role in treating traumatic brain injury (TBI). Herein, we explored the mechanism of MNS in TBI. A TBI-induced coma model (skull was hit by a cylindrical impact hammer) was established in adult Sprague-Dawley rats. Microglia were isolated from newborn Sprague-Dawley rats and was injured by lipopolysaccharide (LPS; 10 ng/mL). Consciousness was assessed by sensory and motor functions. Brain tissue morphology was detected using hematoxylin-eosin staining assay. Ionized calcium binding adapter molecule 1, NeuN and tachykinin receptor 1 (TACR1) level were detected by immunohistochemical assay. Levels of pro-inflammatory and anti-inflammatory factors were measured by enzyme linked immune sorbent assay (ELISA). Levels of TACR1, C-C motif chemokine 7 (CCL7), phosphorylation (p)-P65 and P65 were assessed by quantitative real time polymerase chain reaction (qRT-PCR) and western blot. M1 markers (inducible nitric oxide synthase and CD86) and M2 markers (arginase-1 (Arg1) and chitinase 3-like 3 (YM1)) of microglia as well as the transfection efficiency of short hairpin TACR1 (shTACR1) were assessed by qRT-PCR. Immunofluorescence and flow cytometry assay were used to detect microglia morphology and neuron apoptosis. MNS reduced neuron injury and microglia activation in the TBI-induced rat coma model. MNS reversed the effects of TBI on levels of inflammation-related factors, M1/M2 microglia markers, TACR1, p-P65/P65 and CCL7 in rats. shTACR1 reversed the effects of LPS on inflammation-related factors, M1/M2 microglia markers, microglia activation, neuron apoptosis, p-P65/P65 value and CCL7 level. Our results revealed that MNS improved TBI by reducing TACR1 to inhibit nuclear factor-κB (NF-κB) and CCL7 activation in microglia.

Role of Preoperative Nerve Conduction Studies for Penetrating Hand Injuries Involving the Median Palmar Cutaneous Nerve.

Penetrating lacerations to the hand are a common cause of nerve injury and can lead to debilitating pain and numbness in the distribution of the nerve affected. Owing to an overlap in the cutaneous innervation from different sensory nerves, clinically identifying the injured nerve can be difficult. We present a novel case of isolated injury to the palmar cutaneous nerve from a penetrating knife injury which was detected using 'comparison waveform' nerve conduction studies. Using this technique, we can isolate injuries to the palmar cutaneous branch of the median nerve (PCBmdn) from the median nerve, dorsal radial sensory nerve, and lateral antebrachial cutaneous nerve. In addition, sensory nerve testing identified conduction block as the mechanism of injury, which resolved after surgery at 8 weeks postoperatively. Preoperative nerve conduction study can discern the level of nerve injury to PCBmdn only, thus eliminating the need for median and radial nerve exploration at the forearm, unnecessary incisions, pain, and scarring. The objective of this case report is to illustrate the value of preoperative comparison waveform nerve conduction study, particularly the PCBmdn, in patients presenting with neurologic deficits who have sustained penetrating lacerations to the hand.

Median Nerve Palsy in Pediatric Supracondylar Humerus Fractures Recovers Faster With Open Than Closed Reduction.

BACKGROUND: Management of supracondylar humerus fractures (SCHF) with coexisting median nerve injury is controversial. Although many nerve injuries improve with the reduction and stabilization of the fracture, the speed and completeness of recovery are unclear. This study investigates median nerve recovery time using the serial examination. METHODS: A prospectively maintained database of SCHF-related nerve injuries referred to a tertiary hand therapy unit between 2017 and 2021 was interrogated. Factors related to the injury (vascularity, Gartland grade, open vs. closed fracture) and treatment (fixation modality, adequacy, timing of reduction, vascular and nerve intervention, and secondary procedures) were assessed.Primary outcomes were the motor recovery of Medical Research Council (MRC) grade 4 or 5 in flexor pollicis longus or flexor digitorum profundus (index) and detection of the 2.83 Semmes Weinstein monofilament.A retrospective clinical note review of all SCHF presenting during the same period was also conducted. RESULTS: Of 1096 SCHF, 74 (7%) had an associated median nerve palsy. Twenty-one patients [mean age 7 years (SD 1.6)] with SCHF-related median nerve injuries underwent serial examination. Nineteen (90%) were modified Gartland III or IV, and 10 (48%) were pulseless on presentation. The mean follow-up was 324 days.The mean motor recovery time was 120 days (SD 71). Four (27%) and 2 (13%) patients had not achieved MRC grade 4 by 6 months and 2 years, respectively. Only 50% attained MRC grade 5 at 2 years.When compared with closed reduction, those who underwent open reduction recovered motor function 80 days faster (mean 71 vs. 151 d, P =0.03) and sensory function 110 days faster (52 vs. 162, P =0.02). Fewer patients recovered after closed reduction (8 of 10) than open (5 of 5).Modified Gartland grade, vascular status, adequacy of reduction, and secondary surgery were not associated with recovery time. CONCLUSIONS: Median nerve recovery seems to occur slower than previously thought, is often incomplete, and is affected by treatment decisions (open vs. closed reduction). Retrospective reporting methods may overestimate median nerve recovery. LEVEL OF EVIDENCE: Level III-therapeutic.

Role of ultrasonography for evaluation of nerve recovery in repaired median nerve lacerations.

This study aimed to investigate whether ultrasonographic inspection of the repair site of median nerve lacerations may provide useful evidence about the functional outcome in the affected hand. Forty-three patients with complete transection of the median nerve at the distal forearm were examined at a median of 40.9 months after operation by detailed ultrasonographic imaging and clinical assessment of the affected hand by the Michigan Hand Questionnaire and Rosén-Lundborg Protocol to investigate the quality of nerve healing. The continuity of individual nerve fascicles was assessed and the cross-sectional area of the enlarged nerve at the repair site was measured and compared with the contralateral median nerve at the same level. An enlargement ratio for the repair site of each nerve was calculated and compared with the numeric results obtained from the two clinical tests. A statistically significant reverse correlation was observed between nerve enlargement and the functional results of the repaired nerve.Level of evidence: IV.

Radius palmar plate removal without carpal tunnel release: Correlation between plate position and median nerve symptoms.

We aimed to report the clinical results of volar plate removal without carpal tunnel release in patients with late-onset median neuropathy and to evaluate the relationship between plate position and median nerve symptoms. Part I. Twelve consecutive patients with late-onset median neuropathy treated with volar plate removal without carpal tunnel release were enrolled for analysis. Pre- and post-operative Tinel sign, Phalen and Ten test, subjective rating of tingling sensation, Mayo wrist score and Disabilities of the Arm, Shoulder and Hand (DASH) score were collected. Part II. 232 consecutive patients underwent volar plating for distal radius fracture. The relationships between median nerve symptoms and volar plate prominence on the Soong classification, fracture classification, gender and age were investigated. All cases except one showed complete symptom resolution at final follow-up, with negative Tinel sign and Ten test score of 10/10. Tingling was rated 0 at final follow-up. Mean Mayo wrist and DASH scores improved to 86.7 and 23.1, respectively. The incidence of the median nerve symptoms in our cohort was 5.6%. Even though the odds ratio in Soong grade 2 was 4.0957 (95% CI, 0.93-16.9) compared to the combination of grades 0 and 1, no statistically significant relationship was found between the median nerve symptoms and volar plate prominence (p > 0.05). Plate removal without carpal tunnel release adequately relieved symptoms of late-onset median neuropathy after volar plating in patients with distal radius fracture. LEVEL OF EVIDENCE: IV; Therapeutic.

Anatomic Study of the Motor Branch of the Ulnar Nerve Regarding Carpal Tunnel Surgery: A Cadaveric Study.

Background: Motor branch of the ulnar nerve (MUN) injury during carpal tunnel surgery is rare and it should never be injured during carpal tunnel release (CTR). However, an iatrogenic injury of the MUN can cause catastrophic physical and mental suffering. The aim of our study is to understand the anatomy of the MUN in relation to carpal tunnel in order to prevent iatrogenic injury during CTR. Methods: We dissected 34 fresh cadaver hands and located the MUN in relation to the anatomical axis used for carpal tunnel surgery. Possible mechanisms of injury and the vulnerable area of the MUN were determined along the dissection. Results: The MUN turned towards the thumb distal to hook of hamate. It then travelled on the floor of the carpal tunnel which was formed by intrinsic hand muscles under flexor tendons. The nerve located at 29.39 ± 7.41, 35.01 ± 3.14 and 38.79 ± 4.03 mm (Mean ± SD) in the central axis of ring finger, the vertical axis of the third web-space and the central axis of middle finger respectively. The nerve's turning point, 10.9 ± 2.63 mm distal to the centre of hook of hamate where it lies just below the level of the transverse carpal ligament. Conclusions: Surgeons should be aware of the nerve's location. Surgical dissection or passing of any surgical instruments around the hook of hamate should be done with care. Level of Evidence: Level IV (Therapeutic).

The safety and accuracy of various carpal tunnel injection techniques.

PURPOSE: Carpal tunnel (CT) syndrome continues to be a commonly treated hand pathology. We aimed to evaluate several CT injection techniques for (1) spatial accuracy within the CT and (2) risk of median nerve (MN) injury. Our purpose was to evaluate for any significant differences in accuracy of needle placement within the carpal tunnel and final distance between the needle tip and the MN with each technique. METHODS: Fifteen fresh frozen cadaveric arms were used for this study. Six different injection techniques for CT injection were performed on each specimen, including palmaris longus, ulnar to flexor carpi radialis, trans-flexor carpi radialis, volar radial, volar ulnar, and direct through the palm techniques. After needle placement, a standard open CT release was performed to assess for accuracy of placement within the CT and measure needle position in relation to the MN and other anatomic structures. RESULTS: Accurate intra-CT needle placement was seen in 91% of injections. While there was no significant difference between injection techniques for distance to nearest tendon (p = 0.1531), the trans-flexor carpi radialis (tFCR), volar radial (VR), and volar ulnar (VU) techniques consistently provided the greatest intra-CT distance from needle tip to median nerve (p = 0.0019). The least incidence of intraneural needle placement was found with the tFCR and VR approaches. CONCLUSION: All six injection techniques reliably enter the CT space. The lowest risk to the MN was found with tFCR and VR techniques, and we recommend these techniques for safe and effective needle placement to avoid iatrogenic intraneural injection. LEVEL OF EVIDENCE: Level V: Cadaveric Study.

The position of the median nerve in relation to the palmaris longus tendon at the wrist: a study of 784 MR images.

Iatrogenic injury of the median nerve has been reported after endoscopic carpal tunnel release and corticoid injection. In 784 MR images of the wrist, the position of the median nerve in relation to the palmaris longus tendon was analysed. The ulnar edge of the median nerve was found medial to the palmaris longus tendon in 14% and 36% of patients at the proximal wrist crease and entrance of the carpal tunnel, respectively, compared with 23% and 40% of patients with carpal tunnel syndrome (88 patients). The position of the median nerve in relation to the palmaris longus tendon varies widely. It is suggested that the palmaris longus tendon may not be considered a safe landmark to locate the position of the median nerve and care should be taken when introducing an endoscopic instrument or during steroid injection for carpal tunnel syndrome.Level of evidence: IV.

Risk of nerve injury during elbow arthroscopy: ultrasonographic evaluation of preoperative patients.

BACKGROUND: To clarify the real risk of nerve injury during elbow arthroscopy, the distances of the radial and median nerves to the elbow joint were investigated using ultrasonography in patients who underwent surgery. METHODS: A total of 35 patients who underwent arthroscopic surgery of the elbow were investigated. The distances of the nerves to the capsule and bony landmarks were measured using ultrasonography. The radial nerve distances were measured at the capitellum, joint space, radial head, and radial neck levels. The median nerve distances were measured at the trochlear, joint space, and coronoid process levels. The patients were divided into 2 groups: nine patients in the hydrarthrosis (HA) group and 26 patients in the non-hydrarthrosis (non-HA) group. HA was defined as the intra-articular effusion on magnetic resonance imaging scans. RESULTS: The radial nerve ran closer to the capsule at the radial neck level in the HA group than in the non-HA group (2.0 mm vs. 5.9 mm, P < .01). In the non-HA group, the radial nerve ran closer to the radial head than in the HA group (6.3 mm vs. 8.5 mm, P = .01). The median nerve ran closer to the capsule at the trochlear level in the HA group than in the non-HA group (5.2 mm vs. 8.8 mm, P < .01). Nerves at a distance of ≤2 mm from the capsule were found in 7 patients at the radial neck of the radial nerve and in 2 patients at the trochlear region of the median nerve in the HA group. In the non-HA group, they were found in 3 patients at the radial head and in 1 patient at the joint space of the radial nerve. CONCLUSIONS: The dangerous locations for nerve injury during elbow arthroscopy vary according to hydrarthrosis, and this risk should be recognized during arthroscopic surgery.

Transient Proximal Median Nerve Entrapment in a Tetraplegic Hand Cyclist Following a 24-Hour Endurance Race.

Median nerve entrapment is a frequent disorder encountered by all clinicians at some point of their career. Affecting the distal median nerve, entrapment occurs most frequently at the level of the wrist resulting in a carpal tunnel syndrome. Median nerve entrapment may also occur proximally giving rise to the much less frequent pronator teres syndrome and even less frequent anterior interosseous nerve syndrome, which owing to the paucity of cases may prove challenging to diagnose. An unusual case of anterior interosseous syndrome precipitated by extraordinary exertion in a tetraplegic endurance athlete is presented with ancillary dynamometric, electrodiagnostic, ultrasonographic, and biochemical findings.

Imaging of Nerve Disorders in the Elbow.

Neuropathies of the elbow represent a spectrum of disorders that involve more frequently the ulnar, radial, and median nerves. Reported multiple pathogenic factors include mechanical compression, trauma, inflammatory conditions, infections, as well as tumor-like and neoplastic processes. A thorough understanding of the anatomy of these peripheral nerves is crucial because clinical symptoms and imaging findings depend on which components of the affected nerve are involved. Correlating clinical history with the imaging manifestations of these disorders requires familiarity across all diagnostic modalities. This understanding allows for a targeted imaging work-up that can lead to a prompt and accurate diagnosis.

Combined Use of Chitosan-PGLA Nerve Grafts and Bone Marrow Mononuclear Cells to Repair a 50-mm-long Median Nerve Defect Combined with an 80-mm-long Ulnar Nerve Defect in the Human Upper Arm.

BACKGROUND: Severe peripheral nerve injury, especially the long-distance peripheral nerve defect, causes severe functional disability in patients. There is always a lack of effective repair methods for clinic, and those in practice are associated with side effects. A case study was performed to observe the regenerative outcomes of the surgical repair of long-distance peripheral nerve defects in the upper arm with chitosan-poly(glycolide-co-lactide) (PGLA) nerve grafts combined with bone marrow mononuclear cells (BMMCs). METHODS: The right upper arm of a 29-year-old woman was injured, leaving a 50-mm-long median nerve defect, an 80-mm-long ulnar nerve defect, and muscle and blood vessel disruptions. The nerve defects were repaired by implanting BMMC-containing chitosan-PGLA nerve grafts on the 40th day after injury. A series of functional assessments were carried out from 2 weeks to 66 months after surgical repair. Sensory function was assessed by the pinprick test, two-point discrimination test and Semmes-Weinstein monofilament test. Motor function was evaluated by the range of motion of the wrist joint and muscle power. Autonomic function was monitored by laser-Doppler perfusion imaging (LDPI). Tissue morphology was observed through ultrasonic investigations. RESULTS: No adverse events, such as infection, allergy, or rejection, caused by the treatment were detected during the follow-up period. Sensory and pinprick nociception in the affected thumb, index, and middle fingers gradually restored at 6th month after surgery. The monofilament tactile sensation was 0.4 g in the terminal finger pulp of the thumb and index finger, 2.0 g in the middle finger, and greater than 300 g in the ring finger and little finger at the 66th month. Motor function recovery was detected at the 5th month after surgery, when the muscle strength of the affected forearm flexors began to recover. At the 66th month after surgery, the patient's forearm flexor strength was grade 4, with 80° of palmar flexion, 85° of dorsal extension, 8° of radial deviation, 40° of ulnar deviation, 40° of anterior rotation, and 85° of posterior rotation of the affected wrist. The patient could perform holding, picking up, and some other daily activities with the affected hand. The patient's sweating function of the affected hand was close to the level of the healthy hand. LDPI showed that the skin blood flow perfusion was significantly increased, with perfusion similar to on the normal side in some areas. Neuromusculoskeletal ultrasonography showed the presence of nerve structures. CONCLUSION: These results suggest that chitosan-PGLA nerve grafts combined with BMMCs could effectively repair long-distance nerve defects and achieve good clinical results.

Asymptomatic Penetration of the Median Nerve by a Peripherally Inserted Central Catheter: A Case Report.

We report a rare case in which a peripherally inserted central catheter (PICC) asymptomatically penetrated the median nerve. The patient was a 71-year-old man who displayed no neurological symptoms until 4 days after PICC placement. An ultrasound scan revealed that the PICC had penetrated the median nerve. He underwent surgery to remove the catheter and had no sequelae. When placing a PICC, selecting the brachial vein as a puncture site is associated with a high risk of nerve injury. Furthermore, circumspect observation is needed until withdrawal as neurological symptoms may be absent even when the catheter has punctured a nerve.