Marinacci anastomosis (reverse Martin-Gruber anastomosis): A case report

Variations of the Median Nerve and Carpal Tunnel Syndrome: a Systematic Review of the Literature

Objectives:The purpose of this systematic review is to examine the different variations of the median nerve (MN) and the diagnostic methods used to identify carpal tunnel syndrome (CTS), a common neuropathy resulting from the entrapment of the MN within the carpal tunnel. Understanding the different variations of the MN is crucial in order to prevent injuries during surgical treatment of the syndrome. Materials and methods:Data were extracted from studies published in PubMed. A detailed search in PubMed was performed for studies that reviewed the variations of the MN and CTS. Results:There are two main classifications of the MN, known as the Lanz and Amadio categories. Lanz's classification is the one being mostly used in the surgical literature, with group 3 (Bifid MN) being the main cause of the CTS. Additionally, there are branches and anastomosis of the MN that do not fit into either category, with the third common digital branch being the most injured nerve during carpal tunnel release surgery. Diagnostic techniques for CTS include physical examination combined with NCS tests, magnetic resonance imaging (MRI), ultrasound, or elastography. While NCS has been previously the most commonly used diagnostic method, the recent literature suggests that ultrasound and elastography are the most accurate techniques. Conclusions:In order to minimize injuries during carpal tunnel release surgery, it is crucial to have knowledge on the different variations of the MN that cause CTS. Additionally, this review emphasizes the significance of the current diagnostic methods, which not only make CTS more affordable but also facilitate easier recognition of the condition.

Marinacci Communication With Recovery of the Thumb, Finger, and Wrist Flexion After a High Median Nerve Injury: A Case Report and Review of Literature

The Marinacci communication (MC) contains fibers from the ulnar to the median nerve in the forearm in a proximal to distal fashion. This rare ulnar-to-median nerve anomalous communication has mainly been reported as an incidental finding. In the case presented here, this anatomical variation led to rapid recovery of the thumb, finger, and wrist flexion following a high above elbow complete median nerve injury. A 17-year-old female was involved in an all-terrain vehicle rollover accident and had her right elbow crushed. She presented with no motor or sensory function in the forearm and hand, with a weak monophasic radial artery signal and no palpable pulse. She underwent surgery and was treated with 12 cm interposition cable sural nerve grafting. Although recovery after a high median nerve injury is often prolonged and incomplete, the MC resulted in the recovery of sensation and motor function through muscles typically innervated by the median nerve, following a complete high median nerve injury. In the presence of anomalous recovery following median nerve injury or unusual electrophysiological findings, an MC should be considered as a cause.

Bilateral Martin-Gruber and Marinacci Anastomosis Associated with Carpal Tunnel and Guyon's Canal Syndrome: Case Report

Anastomoses between the median and ulnar nerves are commonly found on electrodiagnostic studies. These anastomoses are usually asymptomatic and are not discovered until nerve injuries occur that lead to unusual motor or sensory deficits. Their presence can cause difficulties in the interpretation of electrophysiological findings for the diagnosis of neuropathies and suppose a risk of iatrogenic damage during surgical procedures. We describe a rare case of bilateral Martin Gruber and Marinacci anastomosis, associated with median and ulnar nerve injuries in the carpal tunnel and Guyon's canal, respectively. The detailed anatomical knowledge of these anastomosis allows the electromyographist to identify them correctly, facilitating the interpretation of the findings and, incidentally, preventing iatrogenic injuries.

Possible points of compression of the ulnar nerve: Tricks and traps that await clinicians from an anatomical point of view

The ulnar nerve can be subject to numerous types of compression. The most common are cubital tunnel and ulnar tunnel syndromes, but there are many others with more uncommon etiologies. The existence of additional communicating branches, median nerve involvement, various types of injuries, and unusual anatomical variations can be a challenge for both diagnosis and treatment. This review presents a comprehensive depiction of ulnar nerve entrapment syndromes with particular reference to their anatomical background, risk factors, and clinical evaluation. Even common disorders can result from atypical morphological changes. It is important to be familiar with them as it is a key ability in daily medical practice.