The anatomical terminology used to identify typical anatomical structures has been condensed over time as evidenced by compendiums of anatomical terminology such as Terminologia Anatomica. Yet, most variant anatomical structures which are diverse, common, and inherently clinically important have not been subject to the same sort of scrutiny and standardization. Thus, superfluous anatomical terminology remains commonplace with regard to anatomical variations. This study utilizes a systematic review to demonstrate a thorough means of assessing anatomical nomenclature. Specifically, the study assesses superfluous terms used to describe singular anatomical variations of the extensors of the 1[st] and 2[nd] digits including extensor pollicis et indicis communis, extensor pollicis et indicis accessorius, and extensor pollicis et indicis as well as the extensors of the 2[nd] and 3[rd] digits including extensor indicis et medii communis, extensor indicis et medius communis, extensor indicis et medii proprius, and extensor indicis et medii accessorius. The systematic review informs the use of extensor pollicis et indicis and extensor indicis et medii as preferable terms due to accuracy in description, brevity, and historical consistency. The reproducible methods and results of this study may serve as a model to henceforth improve anatomical nomenclature in an objective and scientific way. Likewise, the methods and results of this study may be used as lens through which retrospective assessment and interpretation of anatomical variations may be viewed.

Variations of the ankle anatomy are infrequent and exist as supernumerary muscles and tendons. Often understudied and overlooked, their presence can cause many complications of the lower extremity. These muscles, although often asymptomatic, can cause great pain and complications such as tenosynovitis, tarsal tunnel syndrome, lateral ankle instability, and ankle pain when they impinge on the normal anatomy of the patient. The goals of this study were to examine the prevalence of common variants such as the peroneus quartus, peroneus digiti quinti, accessory soleus, flexor accessorius digitorum longus, peroneocalcaneus internus, and tibiocalcaneus internus and to understand the morphological and clinical significance of these accessory muscles and their interactions with surrounding muscles. A literature review of anatomically and clinically based articles was conducted to evaluate the supernumerary muscles. Phrases such as accessory muscles were used to refine the search. Supernumerary muscles have an incidence of 3% to 62%, depending on the muscular compartment and the specific muscle. Although conservative treatments such as orthoses and nonsteroidal anti-inflammatory drugs may help alleviate some pain, surgical treatment yields higher success rates. Identification of supernumerary muscles is mainly by magnetic resonance imaging, but they can be detected by other methods, such as ultrasound. Due to the wide implications of these supernumerary muscles, this study attempted to create a reference guide for physicians to use in aiding their diagnoses and therapeutic plans. Although supernumerary muscles are typically asymptomatic, knowledge of these muscles is beneficial for clinicians in aiding their treatment plans.

The brachioradialis muscle (BR) belongs to the lateral forearm muscle. Typically, the radial nerve innervates it. BR morphological variability, such as split muscular belly, split tendon, or accessory BR (ABR), has been described in the current literature. A 68-year-old female donated cadaver was routinely dissected for research and educational purposes. A variant muscle was identified extending at the right arm's lateral and forearm compartments. It originated from the humerus lateral surface between the deltoid and the triceps brachii lateral head, joined the second muscular head from the brachialis muscle, and inserted into the radius styloid process. According to its origin, course, and insertion, the variant muscle probably corresponded to the BR accessory form. However, in the current literature, the ABR morphology corresponds to an accessory muscle originating adjacent to the typical BR and inserted into the radial tuberosity. At the same time, it was defined as "brachioradialis brevis." In the current case, the variant muscle differed significantly from the current literature due to the origin, insertion, length, and relationship with the typical BR; therefore, the term "brachioradialis longus" seemed adequate to describe this variant muscle.

The flexor digitorum accessorius longus muscle (ALM) can be overlooked as the eliciting factor in patients with tarsal tunnel syndrome (TTS), an entrapment neuropathy of the posterior tibial nerve that elicits sole numbness and pain. Most elicitations are idiopathic, however, mass lesions within the tarsal tunnel can be also implicated. We report an 80-year-old woman whose flexor digitorum ALM led to the onset of bilateral TTS. She had suffered numbness in both soles for 3 years. Magnetic resonance imaging (MRI) of the bilateral tarsal tunnel showed that the posterior tibial nerve was compressed by the arteriovenous complex and in contact with the flexor digitorum ALM. We diagnosed bilateral TTS based on her symptoms and imaging findings, and performed bilateral decompression surgery of the posterior tibial nerve under local anesthesia. The artery on both sides was dislocated for nerve decompression. Because the posterior tibial nerve on the right side was strongly compressed in ankle plantar flexion we excised a portion of the tendon compressing the nerve. Postoperatively her symptoms gradually improved and she reported surgical satisfaction 6 months after the operation. In patients with flexor digitorum ALM-related TTS, the effect of dynamic factors on MRI findings and on surgical treatment decisions must be considered. Intraoperatively, not only the flexor digitorum ALM, but also other potential etiologic factors eliciting TTS must be kept in mind.

The flexor digitorum accessorius longus is an anomalous muscle with a reported prevalence of 1.6%-12.2% in cadaveric studies. Flexor digitorum accessorius longus courses through the tarsal tunnel and has been reported as an etiology of tarsal tunnel syndrome in previous case reports. The flexor digitorum accessorius longus is intimately related to the neurovascular bundle and may impinge on the lateral plantar nerves. However, very few cases of lateral plantar nerve compression by the flexor digitorum accessorius longus have been reported. Herein, we report a case of lateral plantar nerve compression caused by the flexor digitorum accessorius longus muscle in a 51-year-old man who complained of insidious pain at the lateral sole and hypoesthesia at the left third-fifth toe and lateral sole, and the pain improved after treatment of botulinum toxin injection into the flexor digitorum accessorius longus muscle.

In a pig model, pancreatic duct ligation (PL) leads to a complete loss of exocrine function, causing an exocrine pancreatic insufficiency (EPI) without affecting endocrine function, allowing research of clinical effects and therapy options. This study aimed to investigate effects of experimentally induced EPI in juvenile pigs on digestion and intestinal morphology. Eight female juvenile cross-bred pigs (BW 54.8 kg at the start of the study) were included. Three animals were considered as a control (CON group), and in five animals the ductus pancreaticus accessorius was ligated (PL group). During the 10-week trial period, body weight and body measurements were recorded regularly. At the end of the trial, gastrointestinal tract (GIT) was investigated macroscopically and histologically and weight and digesta samples of individual segments were obtained. The pigs in the CON showed a significantly higher apparent total tract digestibility of crude protein and crude fat (87.8 and 79.9%, respectively) compared to PL (52.4 and 16.6%, respectively). Significant differences were noted in relative weights of duodenum, jejunum and colon (with and without digesta) and also in absolute weights of jejunum and colon. The mean number of nuclei in the transverse section in stratum circulare were significantly higher in all intestinal segments in CON compared to PL. Overall, EPI results in impaired nutrient digestibility with a greater filling of the GIT with digesta. The elongation of the small intestine does not represent "stretching" of the intestine, but rather increased synthesis of intestinal tissue.

The extensor hallucis brevis accessorius has rarely been mentioned in the extant medical literature. Here, we present the case of a cadaver found to have such a muscle and discuss the findings. Specifically, the muscle was observed to be degenerated both grossly and histologically. Therefore, both the gross and histological findings are presented. Such unusual cases are of archival value for future authors to compare their findings.