Effect of different positions of splinting on flexor tendon relaxation: a cadaver study

We performed a cadaver study to evaluate how six different static heat-moulded splints affect flexor tendon relaxation. Each splint positioned the wrist and metacarpophalangeal (MCP) joints in different positions. We evaluated the tendon relaxation in 12 fresh adult cadaver forearms by measuring the flexor tendon displacement between two solid markers for each splint. The wrist position ranged from 30° flexion to 45° extension and the MCP joints from 30° to 60° flexion. For each splint, tendon relaxation was achieved relative to the neutral reference position. Tendon relaxation was greatest when the MCP joints were positioned in 60° flexion. We also noted the persistence of tendon relaxation when the wrist was positioned in extension (30° or 45°) as long as MCP joint flexion was maintained (30° or 60°). We conclude that the wrist extension with the MCP joints flexion may optimize tendon relaxation during immobilization after flexor tendon repairs.

Anatomic Considerations for a Posterior Endoscopic Approach to the Cricoarytenoid Joint

Objective: This anatomic study considers the feasibility of a posterior endoscopic approach to the cricoarytenoid joint (CAJ) by describing relationships between readily identifiable anatomic landmarks and the posterior CAJ space in cadaver larynges. Study Design: Anatomic study. Methods: Six adult cadaver larynges (2 male, 4 female) were studied. Digital calipers were used for measurements, and Image J software was used for angle calculations. All cricoarytenoid joints were injected with colored gel via a posterior approach using a 27-gauge needle. Results: The average age of the larynges studied was 78.7 ± 10 years. The average posterior CAJ space (pCAJs) length measured 4.95 ± 0.9 mm. The average distance from the superior aspect of the midline cricoid lamina (MCL) to the center of pCAJs and the corniculate cartilage (CC) to the center of the pCAJs were 8.35 ± 1.5 mm and 14.54 ± 1.9 mm, respectively. The average pCAJs angle of declination (AD) from the horizontal plane was 54° ± 6.2°. All 12 cricoarytenoid joints were successfully injected with colored gel via a posterior approach. Conclusions: The posterior CAJ space can be located surgically using readily identifiable anatomic landmarks. An understanding of this posterior CAJ anatomy may allow for more consistent intra-articular injection and support the development of other CAJ procedures for a range of disorders of vocal fold motion or malposition.

Forces Required to Pull the Superficial Fascia in Facelifts

Purpose: The aims of this study were to characterize the histology of the sideburn and cheek area and to measure the force required to pull the superficial fascia (SF) of Asians in facelift procedures. Methods: The hemiface of a formalin-fixed Korean male adult cadaver (77 years old) was used to study the histology of the sideburn and cheek area. In 42 patients during facelift procedures, the force needed to pull the overlying skin at the midpoint between the sideburn and nasolabial fold 2 mm was measured using a tensiometer. Results: In the cheek, the superficial fatty layer of the superficial fascia (SFS) was found to maintain its thickness throughout the region between the dermis and the membranous layer of the superficial fascia (MSF). The MSF was continuous with the superficial temporal fascia (STF). In the sideburn, the MSF and parotid fascia closely adhered to each other. The force required to move the overlying skin 2 mm when pulling the MSF (10.27 ± 3.64 N) was more than twice as great (217%) as the force required when pulling the SFS (4.73 ± 2.15 N; P < .001). The forces required when pulling the MSF and SFS to move the overlying skin 2 mm were significantly greater in the sideburn area (11.56 ± 3.37 N and 5.52 ± 2.08 N, respectively) than in the cheek area (8.97 ± 3.43 N and 5.52 ± 2.08 N, respectively; P < .001). Conclusion: When lifting the SF at the cheek or sideburn area, lifting the SFS requires less tension than MSF to move the overlying skin. In the cheek area, less tension is needed to move the overlying skin than in the sideburn area.

Variability of the obturator artery with its surgical implications

The vascular anatomy of the pelvis has in the retro pubic space one the most dangerous artery variations for the surgical approach. The aim of this study was to evaluate arise from obturator artery and its implications. Eleven specimens were bisected pelvic an adult cadaver. The iliac artery and femoral artery were identified and divided in their branches. The anomalous origin was noted in 22.72% with an anastomotic branch between the external iliac or inferior epigastric vessels found in 13.69%. The right side showed a greater variation than left side with 27.27% versus 18.18%. Our data suggest that retro pubic space has critical vascular variations of the obturator artery with many probabilities of the lesions.

The Enigmatic Psalterium: A Review and Anatomic Study With Relevance to Callosotomy Procedures

BACKGROUND Recalcitrant seizures after callosotomy procedures are challenging to treat. One commissure, the psalterium, has received little attention. OBJECTIVE To review the literature on this structure, and with dissection, better elucidate its morphology and relationships. METHODS Twenty adult cadaver brains underwent microsurgical dissection of the psalterium. Measurements included the size and distance from the splenium of the corpus callosum and posterior border of the hippocampus tail. Observations included the relationships between the psalterium and the vein of Galen and the fiber direction within this structure. RESULTS The psalterium was identified in all specimens. It intimately contacted the undersurface of the splenium superiorly and the velum interpositum inferiorly. It was always in the midline. Just posterior to the psalterium, the internal cerebral veins were found leaving the velum interpositum to drain into the vein of Galen. In most specimens, the psalterium fibers traveled in the same plane as the commissural fibers of the splenium. Mean width of the psalterium was 11 mm; mean length was 13 mm. Average thickness in the midline was 1.4 mm, and at the lateral edges, it was generally thicker as it joined the fornix with an average of 2 mm. In 30%, efferents from the hippocampus were arranged in the form of a sheet bilaterally rather than the normal bundle-like formation forming the posterior crura. CONCLUSION Better understanding of the commissures of the human brain, including the psalterium, might help the neurosurgeon during procedures near this structure.

Arachnoid membranes in the posterior half of the incisural space: an inverted Liliequist membrane–like arachnoid complex

Object The aim of this study was to describe the similarity of configuration between the arachnoid complex in the posterior half of the incisural space and the Liliequist membrane. Methods Microsurgical dissection and anatomical observation were performed in 20 formalin-fixed adult cadaver heads. The origin, distribution, and configuration of the arachnoid membranes and their relationships with the vascular structures in the posterior half of the incisural space were examined. Results The posterior perimesencephalic membrane and the cerebellar precentral membrane have a common origin at the tentorial edge and form an arachnoid complex strikingly resembling an inverted Liliequist membrane. Asymmetry between sides is not uncommon. If the cerebellar precentral membrane is hypoplastic on one side or both, the well-developed quadrigeminal membrane plays a prominent part in partitioning the subarachnoid space in the posterior half of the incisural space. Conclusions The arachnoid complex in the posterior half of the incisural space can be regarded as an inverted Liliequist membrane. This concept can help neurosurgeons to gain better understanding of the surgical anatomy at the level of the tentorial incisura.