Acquisition of cadavers for anatomy education and research in Malawi.

BACKGROUND: The use of human cadaveric dissection forms an essential part of teaching anatomy to health sciences students in Malawi. Despite worldwide struggles in acquiring sufficient human cadavers for anatomy education, the current recommendations on the best anatomy practices require the use of cadavers exclusively from the body donation programs. The current study aims to describe the sources of cadaveric bodies used for anatomy education in the Malawian context and reflect on the feasibility of using cadavers from the body donation program only. METHODS: A retrospective audit of the cadaveric records for the 2006-2022 academic years at the Kamuzu University of Health Sciences was done. The perceived challenges when sourcing the cadavers were identified and described based on the authors experiences in Malawi. RESULTS: The majority (97.3%) of the cadavers used between 2006 and 2022 were unclaimed bodies. The mean age of the cadavers was 45 years. Most (95.6%) of the unclaimed bodies were males. All the unclaimed bodies were sourced from hospitals. The body donation program in Malawi was patronized by populations of European descent only. Strongly held sociocultural and religious beliefs as well as economic reasons were perceived as significant barriers to acquiring cadavers of the indigenous Malawians through the body donation program. CONCLUSION: Cadavers for anatomy education in Malawi are mainly from unclaimed bodies, similar to other African countries. The authors support the transition from using "mostly unclaimed bodies (and, less often, body donation)" to using "mostly body donation (and, less often, unclaimed bodies)" through awareness campaigns that are targeted to address the prevailing challenges.

Bilateral duplicated inferior vena cava associated with aberrant internal iliac and gonadal veins: A case-based narrative review.

BACKGROUND: The left side anterior retroperitoneal approach is preferred for the management of lumbosacral spine disorders as there is reduced risk for vascular injury. The presence of multiple and uncommon venous variations on either side of the spine, like the bilateral duplicated inferior vena cava (DIVC), may complicate surgery in this region. The current study describes two rare cases of bilateral duplicated inferior vena cava associated with internal iliac and gonadal veins. METHODS: The cases were identified during routine human dissections of the posterior abdominal wall of 89 (45 males, 44 females) individuals. The course, relations and morphometry of each duplicated inferior vena cava were examined and recorded. RESULTS: Two (2.2%) of the 89 (1 male, 1 female) dissected individuals showed the presence of bilateral duplicated infrarenal segments of the inferior vena cava. In both cases, the pre-aortic trunk (vein) was the largest and the left inferior vena cava was the smallest. Both cases of bilateral DIVC presented with anomalous interiliac communicating veins, internal iliac veins, and drainage sites of the left gonadal veins. CONCLUSIONS: The duplicated inferior vena cava may present with associated venous anomalies like those related to the gonadal and internal iliac veins. Knowledge of the duplicated inferior vena cava and its associated venous anomalies may be essential for accurately identifying and diagnosing vascular dysfunction and improving radiological interpretation across multiple surgical specialities.

Estimation of sex using dimensions around the metatarsal diaphyseal nutrient foramen: Application of discriminant function analysis and logistic regression models.

Sex estimation equations are population-specific, and a wider use of multiple bones to generate equations will increase the accuracy of sex estimation in forensic settings. The metatarsal bones have been used previously, however the dimensions around the diaphyseal nutrient foramen have not been utilised in sex estimation. The current study aimed to determine the utility of the dimensions around the nutrient foramen of metatarsal bones in estimating sex in the South Africans of European descent (SAED). Five measurements around the nutrient foramen were taken from a total of 876 metatarsal bones (first to fifth) from 186 individual skeletons (99 males, 87 females) obtained from the Raymond A. Dart Modern Skeletal Collection. Measurements subjected to direct and stepwise discriminant function (DFA) and logistic regression (LRA) analyses included total length, distance from proximal end to nutrient foramen, circumference, and mediolateral and dorsoplantar diameters at the level of the nutrient foramen. The original classification accuracies for multivariable functions of the stepwise and direct DFA ranged from 83.1-88.3% to 85.5-88.3%, respectively. The original classification accuracies for multivariable functions of the stepwise and direct LRA ranged from 83.3%-88.7% to 86.2%-88.3%, respectively. The cross-validation classifications showed a drop of 0-2.4% for DFA and 0.2-1.1% for LRA. The width measurements were better predictors of sex than length. The dimensions around the metatarsal bone nutrient foramen exhibit sexual dimorphism in the SAED. The generated DFA and LRA functions produced high average classification accuracies which are useful in sex estimation during forensic human identification.

Topographical anatomy and clinical implications of the metatarsal diaphyseal nutrient foramina across South African populations.

PURPOSE: Metatarsal fractures often occur around the diaphyseal nutrient foramina (NF) which vary in topography depending on population affinity. Topographical and morphometrical knowledge of the NF is crucial in understanding fracture development and fracture site healing patterns. The current study aimed to describe the topography and the morphometry of the metatarsal diaphyseal NF in South African Africans (SAA), South Africans of European descent (SAED) and South Africans of Mixed Ancestry (SAMA). METHODS: The study examined 4284 dry cadaveric metatarsals from both sexes and sides of these populations for NF topography and morphometry, including the presence, number, location, position, size and direction of the NF on the metatarsal bones. RESULTS: The NF was present in 99.4% of the metatarsals. Most (84.5%) metatarsals examined had a single NF. Most (97.4%) NF were located in the middle third of the metatarsal bones. The median foramina index (FI) of the second metatarsal exhibited population affinity and significant differences were found both on the left second metatarsal (P = 0.043), and the right second metatarsal (P = 0.046). The position of NF was predominantly lateral on the first (92.4%), second (64.9%) and third (59.1%) metatarsals, whilst the position was predominantly medial on the fifth (65.1%) metatarsals. The NF positions on the fourth metatarsals showed the greatest population variability. The first metatarsals had primarily dominant-sized and distally directed NF whilst the second through fifth had primarily secondary-sized and proximally directed NF. CONCLUSION: The topographical anatomy of the metatarsal diaphyseal NF appears similar across the South African populations. Metatarsal bones are highly vascularized bones presenting with multiple nutrient foramina.

Topography and Composition of the Iliolumbar Veins in a South African Cohort: Implications for Spinal Surgery.

STUDY DESIGN: A descriptive cross-sectional study of the anatomical variations, morphometry, and histology of the iliolumbar veins (ILVs). PURPOSE: This study aimed to describe the anatomical variations of the ILVs and determine their tissue composition in South African cadavers of European descent. OVERVIEW OF LITERATURE: A safe anterior surgical approach to the L4/L5 intervertebral disc space requires understanding the anatomy of the ILVs. Limited understanding of ILVs and their variations may lead to inadvertent avulsion of veins with subsequent hemorrhage and damage to the adjacent nerves intraoperatively. Variations in ILVs are population specific, but such reports are limited in the South African population. METHODS: Eighty-nine adult cadavers were dissected to reveal ILV patterns. The variations (origin, course, and drainage pattern), morphometries, and topography of the ILVs were studied. A total of 19 (10 proximal, nine distal) ILVs were processed for hematoxylin and eosin, Masson's trichrome, and Verhoeff's histological staining to determine the tissue composition. RESULTS: The ILVs were identified in 100% of the cases, and 45% of the ILVs were anastomosed to each other bilaterally. The rightside ILVs terminated into the posterior surfaces of the iliac vessels (p =0.001), whereas the left-side ILVs terminated into the lateral surfaces (p =0.001). The left-side proximal ILVs had higher elastic fiber composition (p =0.030). The ratio of the ILVs' elastic fibers to collagen fibers was 1:9, and 61% of the cadavers exhibited type 1 ILV pattern. Moreover, 42% of the ILVs were at the S1 vertebral level with 31% lying between L4 and L5 spinal nerve roots. The obturator nerve coursed anteriorly to the ILVs in 96% of cases. CONCLUSIONS: The ILV variations described for South Africans present new additional patterns, such as bilateral anastomosis and laterality of the terminal drainage. The ILVs have more collagen fibers than elastic fibers, predisposing them to avulsion during surgical retraction. The identification of all the ILVs is crucial to minimize inadvertent hemorrhage and damage to adjacent structures.