Assessing the innervation of the dorsal wrist capsule using modified Sihler's staining

Background: The aim of this study was to assess the innervation of the dorsal articular capsule of the wrist using modified Sihler’s staining. Materials and methods: Thirty dorsal wrist capsules were collected from 15 donors (both sides) within 12 hours of death. All the capsules were collected in the same manner - using the dorsal incision. The specimens were stained according to the protocol of the modified Sihler’s staining technique. The preserved capsules were analysed under 8-16× magnification of an optical microscope for the presence of major nerve trunks, their major and minor branches, and nerve connections. Results: The range of innervation visualised was that the posterior interosseous nerve innervated approximately 60% of the central part; the remaining area was innervated by the dorsal sensory branch of the radial nerve and medial antebrachial cutaneous nerve. The constant findings were the branches departing from the ulnar side of the posterior interosseous nerve and from the radial side, with an exception seen in 2 cases. A communicans branch between the posterior interosseous nerve and medial antebrachial cutaneous nerve was seen in all the specimens. The posterior interosseous nerve innervation extended beyond the level of the carpometacarpal joints II-V. Conclusions: The modified Sihler’s staining technique allows for transparent visibility of the nerves that innervate the dorsal wrist capsule. However, it does not allow as accurate assessment as does histological examination, especially regarding the evaluation of nerve endings. Nevertheless, this method provides a significantly larger area of nerve observation than is provided by histological examination

Median nerve thenar motor branch anatomical variations

Aim. The aim of this study was to determine the prevalence of the different types of the median nerve thenar motor branch and to compare them with literature data.Materials and Methods. This study has been conducted using median nerves dissected from cadavers stored in a 10% solution of formaldehyde at the Department of Anatomy, Jagiellonian University Medical College (JUMC) and cadavers from the Department of Forensic Medicine (JUMC). The research protocol was approved by the Jagiellonian University Ethics Committee (registry KBET/209/B/2002).Results. The studied group comprised of 8 (26,7%) women and 22 men (age between 23-92 years), yielding a total of 60 thenar motor branches (30 right vs. 30 left). Forty-seven (78,3%) nerves were classified as extraligamentous, 12 (20%) were subligamentous and 1 (1,7%) was transligamentous. As for the side of origin of the thenar motor branch in 45 cases (75%) it was the radial side and in 2 cases (3,33%) it was the ulnar side.Conclusions. The obtained results confirm that the extraligamentous type of the thenar motor branch is the most common and that the ulnar origin of the thenar motor branch is the rarest

The use of computer-assisted image analysis in measuring the histological structure of the human median nerve

Background and aim: The aim of this study was to assess the histological structure of the median nerve and its motor branch (number and arrangement of nerve bundles) and the cross-sectional area (CSA) of the median nerve (on the level of the carpal tunnel). Material and methods: This study has been conducted using median nerves dissected from cadavers stored in a 10% solution of formaldehyde at the Department of Anatomy of the Jagiellonian University Medical College and cadavers from the Department of Forensic Medicine of the Jagiellonian University Medical College. After dissection the median nerves were stained with haematoxylin and eosin and histological slides were prepared. These were later photographed (16 x magnification) and analysed using ImageJ software. The research protocol was approved by the Jagiellonian University Ethics Committee (registry KBET/209/B/2002). Results: The studied group comprised 8 women and 22 men (age between 23–92 years), yielding a total of 60 median nerves (30 right vs. 30 left). In 4 (6.67%) cases an accessory motor branch was found. The mean CSA of the median nerve was 0.19 cm2. The median nerves from the right hand had a statistically larger CSA (p = 0.017). The number of nerve bundles in the median nerve varied between 13 to 38 and in the motor branch of the median nerve between 4 to 14. Conclusions: The nerve bundles of the median nerve, at the level of the carpal tunnel, display no particular type of arrangement. ImageJ software proved useful in the assessment of the histological structure of the human median nerve and its motor branc