The prevalence and distribution of the variants of Gantzer’s muscle: a meta-analysis of cadaveric studies / 대한해부학회지

The Gantzer’s muscle is often present in the flexor compartment of the forearm. It lies underneath flexor digitorum superficialis and compresses the anterior interosseous nerve. Furthermore, this muscle frequently bestows an accessory muscle of flexor pollicis longus or flexor digitorum profundus, or sometimes together. The current meta-analysis aims to compute the prevalence of subtypes of Gantzer’s muscle. Major electronic databases (PubMed, Scopus, Google Scholar, etc.) were searched for title and abstract. After removing the duplicate citations, the titles/abstracts were shortlisted with the help of inclusion and exclusion criteria. The shortlisted titles/abstracts were downloaded or collected from the library. The data of all subtypes of Gantzer’s muscle were pooled from shortlisted published manuscripts for meta-analysis. The pooled estimate of other anatomical characteristics was also observed. A total of 59 cadaveric studies of sample size 5,903 were evaluated for pooled prevalence of flexor pollicis longus (accessory head). Similarly, the authors evaluated 14 studies of 1,627 upper limbs for flexor digitorum profundus (accessory head). The unit of analysis was per 100 upper limbs. The Pooled prevalence of accessory muscle of flexor pollicis longus and flexor digitorum profundus were 48% (95% CI, 44%–52%) and 17% (95% CI, 13%–21%), respectively. The Gantzer’s muscle is present in 2/3rd of the upper limbs. Accessory head of flexor pollicis longus is almost three times more common than the accessory head of flexor digitorum profundus. A classification of Gantzer’s muscle is needed to reduce the ignorance of these variants.

Cytological, histochemical, and ultrastructural study of human foetal liver of various gestation with future implications in segmental resection: an anatomical perspective / 대한해부학회지

The liver is the largest gland of the gastrointestinal tract having both exocrine and endocrine functions.Developmentally it arises as a ventral outgrowth from the gut endoderm during 3rd week of intrauterine life. The foetal liver is very important because of its synthetic and hemopoietic potential. The present work aimed to see the detailed histogenesis and development of the foetal liver by cytological, immunohistochemical and ultrastructural study. The liver tissue of nine aborted foetuses of various gestational age were studied. For cytology: special stains like Masson trichrome, periodic acid Schiff and reticulin were used, immunohistochemical staining was performed with triple antibodies (c-myc, Ki-67 and Ber-H2), and for ultrastructure: aluminium mounted specimens were coated with gold and argon gas and observed under scanning electron microscopy (EM). Cytology and immunohistochemistry showed the development of duct patterns and hemopoietic patterns in all stages of fetogenesis. The ductal plate was marked by the layer of dark brown staining cells at the edge of two portal tracts. The haemopoietic cells with sinusoids and aggregation of hepatocytes were observed in the early weeks of gestation. EM showed tree-like branching of a portal canal depicting hepatic segmentation of foetal liver.The organizational changes in lobular pattern, duct pattern, and microstructure of liver during fetogenesis are very crucial to achieve the adult morphology in feature. Histogenesis of the foetal liver follows a multistep process depending upon the gestational age, any deviation from normalcy may lead to structural and functional abnormality later in life.

Identification of most consistent and reliable anatomical landmark to locate and protect radial nerve during posterior approach to humerus: a cadaveric study / 대한해부학회지

The location of the radial nerve (RN) is described with various bony landmarks, but such may be disturbed in the setting of fracture and dislocation of bone. Alternative soft tissue landmarks would be helpful to locate the nerve in such setting. To recognize certain anatomic landmarks to identify, locate and protect RN from any iatrogenic injury during surgical intervention such as open reduction and internal fixation. Forty arms belonging to 20 adult cadavers were used for this study. We measured the distance of RN from the point of confluence of triceps aponeurosis (TA), tip of the acromion and tip of the lateral epicondyle along the long axis of the humerus. These distances were correlated with the upper arm length (UAL). The average UAL was 32.64±0.64 cm. The distance of the RN from the point of confluence of TA (tricepso-radial distance, TRD), tip of acromion (acromion-radial distance) and tip of lateral epicondyle of humerus (condylo-radial distance, CRD) was 3.59±0.16 cm, 14.27±0.59 cm, and 17.14±1.29 cm respectively. No correlation was found with UAL. Statistically, TRD showed the least variability and CRD showed maximum variability. The minimum TRD was found to be 3.00 cm. So this should be considered as the maximum permissible length of the triceps split. The point of confluence of the TA appears to be the most stable and reliable anatomic landmark for localization of the RN during the posterior approach to the humerus.

Re-definition of position and calculation of safe area for axillary nerve in deltoid muscle with its clinical relevance: a cadaveric study / 대한해부학회지

Several authors have made efforts to define the position of the axillary nerve within deltoid muscle and to calculate the so called safe area for this nerve but it still remains a matter of debate. The primary aim of the study was to investigate the acromio-axillary (AA) distance and its correlation with upper arm length. The secondary aim was to re-define the safe area for axillary nerve within deltoid muscle. Sixty shoulders of thirty adult human cadavers were dissected using standard methods. The distance from the anterior and posterior edge of acromion to the upper border of the course of the axillary nerve was measured and recorded as anterior and posterior AA distance respectively. Correlation analysis was done between the upper arm length and AA distance for each limb. The ratios between anterior and posterior AA distance and upper arm length were calculated and mentioned as anterior index and posterior index, respectively. The mean of anterior and posterior AA distance was 5.22 cm and 4.17 cm, respectively. The mean of upper arm length was 29.30 cm. The means of anterior index and posterior indices were 0.18 and 0.14, respectively. There was a significant correlation between upper arm length and both the anterior and posterior AA distance. The axillary nerve was found to lie at variable distance from the acromion. The minimum AA distance was found to be 3.50 cm. So this should be considered as the maximum permissible length of the deltoid split. Upper arm length has strong correlation with both anterior and posterior AA distances. The ideal safe area for the axillary nerve was found to be a quadrangular area above it and the size of which depends on the length of the upper arm.