Degenerative trends of the palmaris longus muscle in a South African population.

The literature reports that the palmaris longus muscle (PL) is only found in mammals in which the forelimbs are weight-bearing extremities. It is suggested that the function of this muscle has been taken over by the other flexors in the forearm. Terms used in the literature to describe the diminishing of this muscle include retrogressive or phylogenetic degenerative trends. The aims of this study were to determine the prevalence of PL in a South African population and whether a phylogenetic degenerative trend for the PL exists. To determine the prevalence of the PL, five groups, representing different age intervals (Years 0-20, 21-40, 41-60, 61-80, and 81-99) were used. A sample of 706 participants of various ages was randomly selected. Statistical analysis included comparisons of the prevalence of the muscle between males and females and left and right sides, using a student t-test. A Chi-squared test was used to determine a possible phylogenetic degenerative trend of PL within the five groups. The sample yielded a bilateral absence of the PL in 11.9% of the cases. The muscle was unilaterally absent on the left side in 7.65% and 6.94% on the right side. The Chi-squared tests revealed a P-value of 0.27 for the left arm and 0.39 for the right arm. No obvious trend could be established for the phylogenetic degeneration of the PL in this study. It would appear that the PL muscle should not be considered as a phylogenetically degenerating muscle in a South African population.

Central venous catheterization--an anatomical review of a clinical skill. Part 2. Internal jugular vein via the supraclavicular approach.

The safe and successful performance of a central venous catheterization (CVC) requires a specific knowledge of anatomy in addition to a working knowledge. Misunderstanding the anatomy may result in failure or complications. This review aims to aid understanding of the anatomical framework, pitfalls, and complications of CVC of the internal jugular veins. CVC is common practice amongst surgeons, anesthesiologists, and emergency room physicians during the preparations for major surgical procedures such as open-heart surgery, as well as for intensive care monitoring and rapid restoration of blood volume. Associated with this technique are certain anatomical pitfalls and complications that can be successfully avoided if one possesses a thorough knowledge of the contraindications, regional anatomy, and rationale of the technique.

Central venous catheterization -- an anatomical review of a clinical skill -- Part 1: subclavian vein via the infraclavicular approach.

The safe and successful performance of a central venous catheterization (CVC) requires a specific knowledge of anatomy in addition to a working knowledge. Misunderstanding the anatomy may result in failure or complications. This review aims to aid understanding of the anatomical framework, pitfalls, and complications of CVC of the subclavian (SCV). CVC is common practice amongst surgeons, anesthesiologists, and emergency room physicians during the preparations for major surgical procedures such as open-heart surgery, as well as, for intensive care monitoring and rapid restoration of blood volume. Associated with this technique are certain anatomical pitfalls and complications that can be successfully avoided if one possesses a thorough knowledge of the contraindications, regional anatomy, and rationale of the technique.

Relation of the external branch of the superior laryngeal nerve to the superior pole of the thyroid gland: an anatomical study.

The external branch of the superior laryngeal nerve (ELN) is intimately associated with the superior thyroid artery (STA) in relation to the superior pole of the thyroid gland, rendering it vulnerable to injury during the ligation of this vessel during thyroidectomy. Although most texts acknowledge the fact that the nerve is in close relation to the STA, there has not been an anatomical study to relate the position of the ELN to the superior pole of the thyroid gland. The aim of this study was to determine the shortest distance, from the most superior point of the thyroid gland, to the ELN. Bilateral micro-dissection on 43 adult cadavers, excluding those with thyroid pathology and previous thyroidectomies, was undertaken. The most superior point of the superior pole of the thyroid gland was identified and the shortest distance to the ELN was measured with a digital calliper (accuracy 0.01 mm). The metric study indicated a mean distance from the ELN to the superior pole of a normal sized thyroid gland of 5.76 mm (range: 2.00-11.26) on the right, and 6.17 mm (range: 2.78-13.48) on the left. From the literature, it is clear that the ELN may even be closer to the superior pole of an enlarged thyroid gland. The recommendation to stay on the substance of the superior pole of the thyroid gland when ligating the STA remains valid, as the nerve is extremely close in relation to the superior pole of the normal thyroid gland.

Anatomical considerations on Sudeck's critical point and its relevance to colorectal surgery.

Sudeck's critical point at the rectosigmoid junction is described as the point of origin of the last sigmoid arterial branch, originating from the inferior mesenteric artery (IMA). There is controversy on the importance of Sudeck's point, and the frequency in which the anastomosis is found. Furthermore, the diameter of the anastomosis, if present, may also impact on the viability of the caudal stump. This study aimed to determine the frequency in which a macroscopic anastomosis occurs, between the superior rectal artery and the last sigmoidal branch, in a cadaver population; the diameter of this anastomosis and the distance from the origin of the IMA to Sudeck's point. Sixty-four cadavers were included in the study, excluding those with previous surgery to the rectosigmoid junction. Sudeck's point was carefully identified and dissected to establish the presence of an anastomosis. Subsequent measurements were performed using a digital caliper (accuracy = 0.01 mm). A macroscopic anatomosis was absent in three cases (4.7%). The mean diameter of the anastomosis when present was 1.9 mm (SD: 0.5 mm), and the distance from the origin of the IMA to Sudeck's point was 55.5 mm (SD: 14.6 mm). Although an anastomosis is present in the majority of cases, the vessel is very small in diameter, and may not be sufficient to meet the demands of the caudal stump. The distance from the origin of the IMA to Sudeck's point is sufficient enough to allow for ligation of the IMA proximal to Sudeck's point.

Superficial radial nerve injury during standard K-wire fixation of uncomplicated distal radial fractures.

This study determines the incidence of superficial radial nerve injury after Kirchner wire insertion. An experienced orthopedic surgeon inserted the K-wires into the radii of 92 adult cadavers. Subsequent dissection of the area exposed the superficial radial nerve and any observed nerve injury was documented. It is clear from the results that nerve injury may still occur as a result of K-wire insertion; however, the current method of K-wire insertion still proves to be a reliable and safe procedure for fixation of distal radial fractures.

Anatomical considerations of the anterior approach for central venous catheter placement.

Central venous catheterization (CVC) entails the catheterization of the superior vena cava via either the subclavian or the internal jugular vein (IJV). This study looked at the frequency in which a needle was inserted into the IJV using the anterior CVC approach, which entails inserting the needle into the apex of Sedillot's triangle, formed by the sternal and clavicular heads of sternocleidomastoid (SCM). The ipsilateral distances from the apex of Sedillot's triangle to the superior aspect of the sternoclavicular joint and the diameter of the IJV were also measured. A needle was inserted into the apex of Sedillot's triangle in 36 adult cadavers with mean age of 62 +/- 19 years (mean +/- SD), mean height of 1.6 +/- 0.18 m, and a mean weight of 55 +/- 16 kg. Subsequent dissections of this area revealed the relation of the needle to the IJV. Results indicate that on the right, the needle was inserted into the IJV in 97.14% of the cases. On the left, the needle entered the IJV in 78.79% of the cases. From the sternoclavicular joint, the apex of Sedillot's triangle was found to be 40.87 +/- 1.62 mm and 38.73 +/- 6.34 mm on the right and left, respectively. The IJV diameter was 17.29 +/- 1.07 mm on the right and 15.30 +/- 0.25 mm on the left. We conclude that the anterior CVC approach is an anatomically accurate technique. It is furthermore important to realize that when performing any invasive procedure, a sound anatomical knowledge of the region is extremely important, as complications are often due to lack of understanding or misunderstanding of the relevant anatomy.

Anatomical considerations of the pediatric ilioinguinal/iliohypogastric nerve block.

BACKGROUND: The ilioinguinal/iliohypogastric nerve block is safe, effective and easy to perform in order to provide analgesia for a variety of inguinal surgical procedures in pediatric patients. A relatively high failure rate of 10-25% has been reported, even in experienced hands. The aim of this study was to determine the exact anatomical position of the ilioinguinal and iliohypogastric nerves in relation to an easily identifiable constant bony landmark, the anterior superior iliac spine (ASIS) in neonates and infants. The current ilioinguinal/iliohypogastric nerve block techniques were also evaluated from an anatomical perspective. METHOD: Dissections were performed on a sample of 25 infant and neonatal cadavers (mean weight = 2.2 kg; mean height = 45.6 cm). The distance from the ASIS to both the ilioinguinal and iliohypogastric nerves, on a line connecting the ASIS to the umbilicus was carefully measured using a digital caliper. Three techniques, commonly used in clinical practice, were simulated on the anatomical specimens. RESULT: The left and right ilioinguinal nerves were closer to the ASIS than previously described, i.e. 1.9 +/- 0.9 mm (mean +/- sd) and 2.0 +/- 0.7 mm, respectively. The mean distance from the left and right iliohypogastric nerves to the ASIS are 3.3 +/- 0.8 mm and 3.9 +/- 1.0 mm, respectively. CONCLUSIONS: We suggest that the high failure rate of the ilioinguinal/iliohypogastric nerve block in this age group could be due to lack of specific spatial knowledge of the anatomy of these nerves in infants and neonates. This cadaver-based study suggests an insertion point closer to the ASIS, approximately 2.5 mm (range: 1.0-4.9) from the ASIS on a line drawn between the ipsilateral ASIS and the umbilicus.