Anomalous palmar cutaneous branch of the median nerve in the distal forearm: case report

At-Risk Median Motor Branch to the Thenar Musculature Crossing Under the Flexor Carpi Radialis in the Forearm: A Case Report

CASE

A 77-year-old woman who sustained a distal radius and ulna fracture underwent open reduction internal fixation through a standard flexor carpi radialis (FCR) approach. On dissection, a proximal division of the median nerve was identified, with an aberrant motor branch crossing radial to ulnar deep to FCR and superficial to flexor pollicis longus.

CONCLUSION

Although many anatomic variants of the median nerve have been described, the current case demonstrates a particularly important median motor branch variant, imposing a substantial risk of iatrogenic injury during a standard FCR approach.

An Anatomical Variant of the Palmar Cutaneous Branch of the Median Nerve: A Case Report

There is a risk of injury to the palmar cutaneous branch of the median nerve (PCBMN) during a volar approach to the carpus or the distal radius. Anatomic variations of the PCBMN increase this risk. We report an anatomic variant of the PCBMN that coursed superficial and radial to the flexor carpi radialis (FCR), reinforcing the need for meticulous subcutaneous dissection to protect the nerve during a volar approach to the distal radius. In this case, identification of the PCBMN variant warranted a modified surgical approach, ulnar to the FCR instead of radial in order to avoid iatrogenic injury. Level of Evidence: Level V (Therapeutic).

Compression of the palmar cutaneous branch of the median nerve secondary to previous rupture of the palmaris longus tendon: Case report

INTRODUCTION

We report an unusual case compression of the palmar cutaneous branch of the median nerve(PCBNN).

PRESENTATION OF CASE

A 52-year-old woman presenting with previous rupture of the palmaris longus tendon. During surgery, we found that the end of the tendon had formed nodules. After removing the nodules, the PCBMN was released, and half a year later, the abnormal feelings had disappeared.

DISCUSSION

We aim to remind surgeons of this type of compression and to highlight the importance of maintaining vigilance in order to avoid nerve injury.

CONCLUSION

PCBMN needs to be paid more attention and damaged tendons should be repaired.

Anomalous Courses of the Palmar Cutaneous Branch of the Median Nerve in Relation to the Flexor Carpi Radialis Tendon for ORIF of Distal Radius Fractures

Background: The purpose of this study was to prospectively document the incidence of variations in the course of palmar cutaneous branch of the median nerve (PCBMN) that may increase the risk of injury to the nerve during the flexor carpi radialis (FCR) approach. We hypothesize that the incidence of anomalous branching of the PCBMN around the FCR sheath will be approximately 5%. Methods: All cases that met inclusion criteria between November 2013 and March 2018 were included. The operating surgeon made the final decision for operative intervention using the FCR approach. Each surgeon performed the standard FCR approach to the distal radius. The branching location from the median nerve, the relationship to the FCR sheath, and the course of the PCBMN were recorded. Results: In total, 101 distal radius fractures were included. The average branching point of PCBMN was 5.2 cm from the distal wrist crease (range = 3.3-9.0). There were 26 anomalous branching patterns of PCBMN. Nineteen (18.8%) crossed volar, dorsal, or ran within the FCR sheath. Six PCBMN were found within the FCR sheath, 1 penetrated the FCR sheath, 6 crossed volar to the FCR sheath, and 6 were dorsal to the FCR tendon sheath. When comparing the branching patterns of the PCBMN from the median nerve, 4 branched from the volar aspect, 2 branched from the dorsal aspect, and 1 branched from the ulnar aspect of the median nerve. Conclusions: Variation in the course of the PCBMN relative to the FCR sheath is more than previously thought and can be expected in approximately 18.8% of patients.

Sonographic evaluation of uncommonly assessed upper extremity peripheral nerves: anatomy, technique, and clinical syndromes

Targeted ultrasound of the median, ulnar, and radial nerves is a well-established technique for suspected upper extremity peripheral neuropathy. However, sonographic imaging of the brachial plexus and smaller peripheral nerve branches is more technically difficult and the anatomy is less familiar to many radiologists. As imaging techniques improve, many clinicians refer patients for imaging of previously less-familiar structures. In addition, some patients may present with injuries that could involve local neurovascular structures. Finally, patients presenting with isolated peripheral neuropathies may be referred for perineural injections with local anesthetic for diagnostic purposes, or steroid for therapeutic reasons. This requires sonologists to have a firm understanding of the courses of these nerves and the surrounding anatomic landmarks that can be used to accurately identify and characterize them. We discuss clinical syndromes referable to specific peripheral nerve branches in the upper extremity, the relevant anatomy, and sonographic technique.

Volar-Ulnar Approach for Fixation of the Volar Lunate Facet Fragment in Distal Radius Fractures: A Technical Tip

The volar Henry approach is most commonly used for surgical fixation of distal radius fractures. However, this approach is limited in achieving adequate exposure for the fixation of the volar-ulnar portion of the distal radius, rendering it difficult for the ideal placement of the fixation construct. We propose the use of the extensile volar-ulnar approach for fixation of distal radius fracture involving a small volar-ulnar fragment. This approach allows optimal reduction of the sigmoid notch and the volar lunate facet, which anatomically reduces both the radiocarpal joint and the sigmoid notch. In addition, extension of this approach may safely be performed if concomitant carpal tunnel release is necessary.

Incidence of an Anomalous Course of the Palmar Cutaneous Branch of the Median Nerve During Volar Plate Fixation of Distal Radius Fractures

PURPOSE

Volar plating of distal radius fractures using an approach through the flexor carpi radialis (FCR) sheath is commonplace. The palmar cutaneous branch of the median nerve (PCB) is considered to run in a position adjacent to, but outside, the ulnar FCR sheath. Anatomic studies have not identified anatomic abnormalities relevant to volar plating. The purpose of this study was to determine the frequency of anomalous PCB branches entering the FCR sheath during volar plating.

METHODS

This observational study involved 10 attending hand surgeons during a 7-month period (July 2015-January 2016). Surgeons assessed, documented, and reported any PCB anomalies that were encountered during volar plating through a trans-FCR approach.

RESULTS

There were 182 volar plates applied that made up the study group. There were 10 cases (5.5%) of anomalous PCBs entering the FCR sheath. In 4 cases, the PCB pierced the radial FCR sheath proximally, crossed beneath the tendon, and traveled distally on the ulnar side. In 4 other cases, the PCB entered the FCR sheath proximally on the ulnar or central aspect of the sheath and remained within the sheath, staying along the ulnar or dorsal side of the tendon. In 1 case, the PCB pierced the ulnar distal aspect of the sheath and split into 2 branches. In 1 case, the PCB ran within the sheath along the radial aspect of the FCR.

CONCLUSIONS

Anomalies in the course of the PCB are more common than often considered. These variants are at risk during volar surgical approaches to the wrist that proceed through the FCR sheath.

CLINICAL RELEVANCE

Although dissecting along the radial side of the FCR sheath may protect the PCB in most cases, care must be taken to identify anomalous branches (if present) and protect them during surgery.

Anterolateral surgical approach to the malunited distal radius fracture for corrective osteotomy and bone-graft harvest

The most common complication after distal radius fractures is union with deformity. When symptomatic, distal radial malunions may require operative intervention. Numerous approaches to the distal radius have been described. Most volar approaches involve sectioning the brachioradialis and opening the first extensor compartment to permit adequate exposure. When bone graft is required, this may necessitate a separate incision and further add to the morbidity. We present an alternative anterolateral surgical approach to the distal radius, which allows for excellent exposure, and minimal trauma to the tendons while permitting harvest of local bone graft through the same incision.

Surgical exposures of the radius and ulna

The forearm contains many muscles, nerves, and vascular structures that change position on forearm rotation. Exposure of the radial shaft is best achieved with the Henry (volar) or Thompson (dorsal) approach. The volar flexor carpi radialis approaches are used increasingly for exposure of the distal radius. Although the dorsal approach is a safe utilitarian option with many applications, its use for managing fracture of the distal radius has waned. Potential complications associated with radial exposure include injury to the superficial branch of the radial nerve, the lateral antebrachial cutaneous nerve, and the cephalic vein. Dorsal and ulnar proximal radial exposures are associated with increased risk of injury to the posterior interosseous nerve. With surgical exposure of the ulna, care is required to avoid injuring the dorsal cutaneous branch of the ulnar nerve.