Accessory Flexor Carpi Ulnaris Muscle in Humans: A Rare Anatomical Case with Clinical Considerations

Anatomical variations of the forearm flexor muscles are occasionally encountered. Though usually observed incidentally during autopsies or imaging studies, they may at times cause concern due to associated clinical symptoms. This report presents a case of unilateral accessory flexor carpi ulnaris (AFCU) muscle observed in a human male cadaver aged 78 years. During routine cadaveric dissection, an anomalous AFCU muscle was observed in the left forearm of a human male cadaver aged 78 years. Standard institutional guidelines pertaining to the use of human cadaver for teaching and research were followed. A thorough literature review about the flexor carpi ulnaris (FCU) through the PubMed, Embase and Google scholar databases was undertaken, using the keywords - accessory flexor carpi ulnaris muscle, aberrant flexor carpi ulnaris muscle and anatomical variation of flexor carpi ulnaris muscle. Relevant gross anatomical findings were recorded and photographed. AFCU was identified on the medial aspect of the distal third of the left forearm. The AFCU was found originating from the ante-brachial fascia and the fascia covering the FCU on the left forearm, forming a small separate belly deep to the main muscle. It terminated as a thin tendon running alongside the hypothenar muscles and attached distally to the base of the proximal phalanx of the little finger. The AFCU was found to be innervated by a branch of the ulnar nerve. Awareness about the rare AFCU muscle is clinically important as a possible cause of ulnar nerve compression but also as a possible graft in reconstruction surgeries.

A Bitendinous Palmaris Longus: Aberrant Insertions and Its Clinical Impact - A Case Report

Palmaris longus, phylogenetically a retrogressive muscle, exhibits significant anatomical variations compared to other muscles of the upper extremity. It is of great surgical importance because, it is the first option tendon for graft procedures in various cosmetic, plastic and reconstructive surgeries. It has also been widely used in various tendon transfer procedures in treating facial paralysis, ptosis correction, lip augmentation and digital pulley reconstruction. We report a rare variant pattern of Palmaris longus with duplicated tendons and with multiple insertions to thenar and hypothenar muscles, fasciae and the flexor retinaculum along with its normal continuation as palmar aponeurosis. Variations in its insertions not only contribute, but also augment the various pathological processes such as Dupuytren's contracture, Carpal tunnel and Guyon's syndromes. So it is of utmost importance for surgeons, physicians and radiologists, to be aware of these variations, well in advance.

Separate Belly and Tendon of Flexor Digitorum Superficialis to the Fifth Digit

Variation in the origin of long flexor tendons in the anterior compartment of forearm is common. During routine cadaveric dissection at Melaka Manipal Medical College (Manipal Campus), we observed a separate muscle belly and tendon of flexor digitorum superficialis (FDS) to the fifth digit in the right upper limb of a 60 year-old male cadaver. The anomalous muscle belly originated from the common flexor tendon from the medial epicondyle of the humerus and continued as a thin tendon at the middle of the forearm to get inserted into the middle phalanx of the fifth digit. This can be considered as a case of split flexor digitorum superficialis. Such muscle variations and knowledge of their frequency, appearance, and location can be helpful for surgeons.