Riché-Cannieu Anastomosis: Structure, Function, and Clinical Significance

Other median neuropathies

Median mononeuropathy is common, with carpal tunnel syndrome the most frequently encountered acquired mononeuropathy in clinical practice. However, other disorders of the median nerve and many known anatomical variants can lead to misdiagnosis and unexpected surgical complications if their presence is not correctly identified. A number of inherited and acquired disorders can affect the median nerve proximal to the wrist, alone or accompanied by other affected peripheral nerves. Recognizing other disorders that can masquerade as median mononeuropathies can avoid misdiagnosis and misguided management. This chapter explores median nerve anatomical variants, disorders, and lesions, emphasizing the need for careful examination and electrodiagnostic study in the localization of median neuropathy.

Anatomical considerations of US-guided carpal tunnel release in daily clinical practice

Carpal tunnel syndrome is the most frequent compression neuropathy with an incidence of one to three subjects per thousand. As specific anatomical variations might lead to unintended damage during surgical interventions, we present a review to elucidate the anatomical variability of the carpal tunnel region with important considerations for daily clinical practice: several variants of the median nerve branches in and around the transverse carpal ligament are typical and must - similarly to the variant courses of the median artery, which may be found eccentric ulnar to the median nerve - be taken into account in any interventional therapy at the carpal tunnel. Unintended interference in these structures might lead to heavy arterial bleeding and, in consequence, even underperfusion of segments of the median nerve or, if neural structures such as variant nerve branches are impaired or even cut, severe pain-syndromes with a profound impact on the quality of life. This knowledge is thus crucial for outcome- and safety-optimization of different surgical procedures at the volar aspect of the wrist and surgical therapy of the carpal tunnel syndrome e.g., US-guided carpal tunnel release, as injury might result in dysfunction and/or pain on wrist motion or direct impact in the region concerned. For most variations, anatomical and surgical descriptions vary, as official classifications are still lacking.

Re-evaluation of the Indications for the Camitz Procedure in Severe Carpal Tunnel Syndrome

PURPOSE

The modified Camitz procedure has been used to improve thumb opposition in patients with severe carpal tunnel syndrome (CTS), although its indications remain controversial. This study compared the functional recovery of thumb opposition following carpal tunnel release with and without a concomitant Camitz procedure. We used the Carpal Tunnel Syndrome Instrument questionnaire (CTSI) and the compound muscle action potential of the abductor pollicis brevis (APB-CMAP) to assess the recovery.

METHODS

Five hundred sixty-seven hands underwent surgical treatment for CTS following electrophysiologic studies and the CTSI. The procedures included carpal tunnel release (either endoscopic carpal tunnel release [ECTR] or open carpal tunnel release [OCTR]) and OCTR with a Camitz procedure. One hundred thirty-six patients with absent preoperative APB-CMAP constituted the material of our study. The CTSI and APB-CMAP recoveries between the "ECTR/OCTR group" and the "Camitz group" were compared before surgery and at three, six, and 12 months after surgery.

RESULTS

There were no statistically significant differences in recovery between the "ECTR/OCTR group" and the "Camitz group" according to the three scales of CTSI (symptom severity scale, functional state scale, and FS-2 item, buttoning clothes: an alternative test of thumb opposition) and the APB-CMAP.

CONCLUSION

Carpal tunnel release procedures resulted in the useful recovery of thumb opposition without the need for Camitz, even if APB-CMAP did not fully recover. The action of the other synergistic muscles acting on the thumb and the sensory recovery may have contributed to the recovery of thumb opposition. The Camitz procedure also may be only rarely indicated for hands affected by severe CTS.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Anatomical Variants of the Upper Limb Nerves: Clinical and Preoperative Relevance

Profound knowledge of nerve variations is essential for clinical practice. It is crucial for interpreting the large variability of a patient's clinical presentation and the different mechanisms of nerve injury. Awareness of nerve variations facilitates surgical safety and efficacy. Clinically significant anatomical variations can be classified into two main groups: variability in the course of the nerve and variability of structures surrounding the nerve. In this review article we focus on the most common nerve variants of the upper extremity and their clinical relevance.

A History of Anatomical Eponyms of the Ulnar Nerve

The ulnar nerve has a long and often misunderstood history with eponym usage. We describe the history of eponym usage in the anatomy of the ulnar nerve-who, when, what, where, and how. The relevant anatomy is investigated from proximal to distal, from the Arcade of Struthers to Osborne's band, to forearm ulnar nerve to median nerve connections, to Guyon's canal. We hope to provide a historical perspective of interest, resolve any controversies in semantic definitions, and create a comprehensive library of eponymous terms related to ulnar nerve anatomy.

Clinical-electrodiagnostic correlates in three cases of Riche-Cannieu anomaly (all-ulnar hand)

Abstract.

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.

Innervation and vascular supply of the first dorsal interosseous muscle and palmar interosseous muscle of the index: An anatomic descriptive study

INTRODUCTION

The first dorsal interosseous muscle (FDI) and palmar interosseous muscle of the index (P2I) are essential for the strength and mobility of the index finger. This study aims to describe the course of the deep branch of the ulnar nerve (DBUN) and the blood supply to these muscles.

MATERIAL AND METHODS

An anatomical cadaver study was carried out with 14 upper limbs from fresh, non-embalmed cadavers. All limbs were filled with an equal amount, based on weight, of colored silicone and diluent that was combined and catalyzed with 5% curing agent. The location of the DBUN's termination was specified relative the carpometacarpal joint. Every artery supplying either muscle was identified and documented.

RESULTS

The DBUN had a slightly convex path, distal to the hook of the hamate and penetrated the FDI muscle at an average 41% of the second metacarpal length. An average of 1.3 branches to the P2I and 2.6 branches to the FDI were found. Four artery pedicles coming from the deep palmar arch supply the FDI with an average of one consistent and exclusive pedicle to the FDI and three pedicles heading to the P2I. According to the classification of Mathes and Nahai, the FDI has a type 2 blood supply and the P2I has a type 3 blood supply.

CONCLUSION

In-depth knowledge of the vascular network supplying the FDI and P2I muscles and the course of the DBUN is essential when the DBUN is damaged or when dissecting these muscles for index pollicization.