Accessory part of the deltoid muscle.

The shoulder and arm region has numerous morphological variations. The deltoid muscle usually consists of three parts: anterior, middle and posterior. This case report describes a very rare deltoid muscle variant, an addition to the spinal part that is attached proximally at the infraspinatus fascia and the spine of the scapula. The distal attachment transforms directly into the brachialis muscle. Additional parts can affect the biomechanics and function of the joints significantly.

A three-headed plantaris muscle fused with Kaplan fibers: potential clinical significance.

The plantaris is a short, small muscle that usually originates at the popliteal surface of the femur and has a long, thin tendon that typically inserts into the calcaneal tuberosity. Its role and degree of development have been objects of debate for years. Some authors consider it a vestigial muscle while others believe it is a process of its development. The clinical significance of plantaris muscle is usually related to its morphological variation, which is common and well described in the literature. These variations are often a risk factor for many ailments and disorders. We would like to present another, very rare case of three-headed plantaris muscle (fused with distal Kaplan fibers), and consider what clinical implications it may have.

A very rare case of the accessory palmaris longus muscle and clinical significance.

The palmaris longus muscle is located in the forearm region. It morphological variability was noted during standard anatomical dissection of the upper limb. The muscle was characterized by a normal course, i.e. originating from the medial humeral epicondyle and inserting to the palmaris aponeurosis, but a small additional tendon attached to the flexor retinaculum was observed in its distal part. An accessory palmaris longus muscle was also observed nearby. Interestingly, this accessory muscle was reversed, and the first part was not muscular, but tendinous, represented by two tendons originating from the common muscular mass attached to the medial epicondyle of the humerus; these later connected together, creating one muscle belly distally attached to the flexor retinaculum. This additional structure was innervated by a neural branch from the median nerve and the ulnar artery was responsible for blood supply. The course of the median nerve is also clinically important, because before entering the carpal tunnel, it was located directly under the accessory palmaris longus muscle. In turn, the ulnar artery passed through a special hole created by the flexor digiti minimi brevis and flexor retinaculum, before passing under the palmaris brevis muscle.

Congenital, Acquired, and Trauma-Related Risk Factors for Thoracic Outlet Syndrome-Review of the Literature.

Thoracic outlet syndrome is a group of disorders that affect the upper extremity and neck, resulting in compression of the neurovascular bundle that exits the thoracic outlet. Depending on the type of compressed structure, the arterial, venous, and neurogenic forms of TOS are distinguished. In some populations, e.g., in certain groups of athletes, some sources report incidence rates as high as about 80 cases per 1000 people, while in the general population, it is equal to 2-4 per 1000. Although the pathogenesis of this condition appears relatively simple, there are a very large number of overlapping risk factors that drive such a high incidence in certain risk groups. Undoubtedly, a thorough knowledge of them and their etiology is essential to estimate the risk of TOS or make a quick and accurate diagnosis.

An unreported innervation of the coracobrachialis longus by the radial nerve: a potential pitfall for clinicians.

PURPOSE: The aim of the presented case is to describe an unprecedented innervation of the coracobrachialis longus muscle by the radial nerve. METHODS: An 82-year-old body donor at death was subjected to a routine anatomical dissection for teaching and research purposes at the Department of Anatomical Dissection and Donation in Lodz, Poland. RESULTS: We have found an additional branch of the radial nerve, which departed from it just below its beginning. Its initial section ran alongside the radial nerve in the axilla, then headed medially accompanying superior ulnar collateral artery. Then, it reaches the coracobrachialis longus muscle and is the only one to innervate it. CONCLUSIONS: The brachial plexus (BP) is very variable and well understood. Nevertheless, we must remember that there may still be variations in its structure, which may involve problems at every stage of diagnosis and treatment of diseases associated with its structures. Their knowledge is extremely important.

The effect of morphological variability of Dorello's canal on surgical procedures - a review.

Dorello's canal is an arched structure of bone-fibrous character located in the petroclival venous confluence atop the petrosal bone in the petroclival region. It is bordered by the petrosphenoidal ligament, the petrous part of the temporal bone and the lateral border of the upper part of clivus. Its content in the vast majority of variants comprises the abducens nerve, the inferior petrosal sinus, the venous drainage and the dorsal meningeal artery or its medial branch. With the development of microsurgical techniques, this area has gained huge clinical importance, mainly concerning the order in which the above-mentioned elements (especially the position of the abducens nerve) are arranged in relation to each other. These structures appear in different variant forms and necessitate an individual clinical approach. The main purpose of this review is to present condensed information about possible intercorrelations among them and to indicate, on the basis of the available literature and research, possible surgical approaches and the need to consider the variability when treatments in this region are planned.