A cadaver study on preserving peroneal nerves during ankle arthroscopy

BACKGROUND

Ankle arthroscopy is an important diagnostic and therapeutic procedure, but neurovascular injury remains a disadvantage. By understanding the anatomy of the superficial peroneal nerve (SPN) and deep peroneal nerve (DPN) the risk of nerve injury can be minimized.

METHODS

Thirty-four lower limbs from 17 cadavers were dissected to find the safest anatomical points easily during arthroscopy.

RESULTS

There was a single branch of the SPN in eight of 34 specimens (23.5%); type 1), two branches in 18 (52.9%; type 2), three branches in six (17.7%; type 3) and four branches in two specimens (5.9%; type 5) at the level of the talocrural (TC) joint. The closest SPN branch to lateral border of the TC joint was 14 +/- 8.4 mm. There was no branch of the SPN or DPN medial to the extensor hallucis longus tendon in any specimen. The DPN bifurcation was 6.5 mm proximal to the TC joint in a single specimen (2.9%) and 14.5 +/- 5.5 mm distal to TC joint in 26 specimens (76.5%). In four specimens (11.8%), the DPN bifurcation was at the same level with the TC joint. In three specimens (8.8%), there was no bifurcation of the DPN.

CONCLUSIONS

From this study the anatomic landmarks defining the medial midline portal are safely away from the SPN and DPN and their respective branches. Clinical studies are needed to define its safety during ankle arthroscopy.

CLINICAL RELEVANCE

This study proves that the medial midline portal is the best portal for the anterior arthroscopic procedures.

Dimensions of the anterior tarsal tunnel and features of the deep peroneal nerve in relation to clinical application

BACKGROUND

The aim of this study was to demonstrate anatomical features of the anterior tarsal tunnel and the deep peroneal nerve and to discuss the importance of these structures for the anterior tarsal tunnel syndrome and some other surgical approaches to minimize the injury risk.

METHODS

Lower limbs of 18 formalin fixed cadavers were examined. The limbs showed no evidence of pathology or trauma.

RESULTS

The lateral length of the tunnel was 21.7 +/- 4.3 mm and the medial length of the tunnel was 55.0 +/- 9.0 mm. The width of the tunnel at the inferior border between the extensor hallucis longus and extensor digitorum longus tendons was 12.6 +/- 2.1 mm. The location of the deep peroneal nerve bifurcation was in the anterior tarsal tunnel in 31 specimens (86.1%) and distal to the tunnel in two specimens (5.6%). In three specimens (8.3%) there was no bifurcation because of the absence of the medial terminal branch of the deep peroneal nerve. In these three specimens, the superficial peroneal nerve distributed to the adjacent sides of the great and second toes. Bifurcation above the tunnel was not observed in our specimens. There was connection between the deep peroneal nerve and the superficial peroneal nerve in 10 specimens (27.8%) in the first interdigital space. During the observations, the presence of a fibrous band over the nerve and vessel was noted in 22 specimens (61.1%).

CONCLUSIONS

We believe that a detailed anatomic knowledge of the anterior tarsal tunnel and the deep peroneal nerve will be of help during surgical approaches to this area and the diagnosis of the problems related to the peripheral nerves on the dorsum of the foot.

Localization of the Marginal Mandibular Branch of the Facial Nerve

The aim of this study was to observe the course of the marginal mandibular branch of the facial nerve (MMBFN) in relation to the inferior border of the mandible and parotid gland and its relevance to surgical procedures such as rhytidectomy and parotid gland surgery. In this study, 50 specimens were dissected. The relationships between the MMBFN and the inferior border of the mandible were recorded and analyzed. We found that posterior to the facial artery, the MMBFN ran above the inferior border of the mandible in 37 (74%) of the specimens. In 11 (22%) specimens, below the inferior border of the mandible it was divided into two branches at the crossing point with the facial artery. In 2 (4%) specimens the MMBFN divided into two branches at the point of emergence from the parotid gland. There were no statistical differences between the left and right sides, and both sexes. The MMBFN is one of the most vulnerable branches to surgical injury because of its location. For this reason, the surgeons who are willing to operate on this area, especially for the rhytidectomies, should have a true knowledge about the anatomy of this branch.

The relationship of the posterior inferior cerebellar artery to cranial nerves VII–XII

The posterior inferior cerebellar artery (PICA) is the largest branch of the vertebral artery. It usually arises at the anterolateral margin of the medulla oblongata close to the lower cranial nerves. The PICA had the most complex relationship to the cranial nerves of any artery and it is frequently exposed in approaches directed to the fourth ventricle. The aim of this article is to describe the anatomical relationship of the PICA to the lower cranial nerves. In this study, 12.5% of PICAs passed between the glossopharyngeal and vagus nerves, 20% between the vagus and accessory nerves, and 65% through the rootlets of the accessory nerve. The lateral medullary segment of the PICA showed a lateral loop which in 20% specimens pressed against the inferior surfaces of the facial and vestibulocochlear nerves. The lateral medullary segment of the PICA in 20% specimens passed superior to the hypoglossal nerve, in 47.5% through the rootlets of the hypoglossal nerve, and in 30% inferior to the hypoglossal nerve. The findings on the relationship of the PICA to the lower cranial nerves could be helpful in microsurgery of this region.

Asterion as a surgical landmark for lateral cranial base approaches

INTRODUCTION

When approaching the posterior fossa and posterolateral cranial base, surface landmarks are helpful in locating the junction of the transverse and the sigmoid sinus.

MATERIAL AND METHODS

On 100 skull halves a 2mm drill bit was externally placed over the asterion and was drilled through the bone perpendicular to the skull surface. Various positions of the asterion and its distance from the root of the zygomatic process of the temporal bone, from the suprameatal crest and the mastoid tip were investigated.

RESULTS

The position of the asterion has been found to be located superficial to the transverse-sigmoid sinus junction in 87% of all samples, inferior to the transverse-sigmoid sinus junction in 11% and superior to the transverse-sigmoid sinus junction in 2%. The distance from the asterion to the root of the zygoma has been determined to be 54.6+/-5.5mm. The distance between asterion and Henle's spine was 45.2+/-5.2, and from asterion to Frankfurt Horizontal Plane 15+/-7.5mm.

CONCLUSION

Asterion varies regarding its cephalocaudal position. The findings of this study might have direct consequences for transmastoid and retrosigmoid approaches for microvascular trigeminal root decompression and combined petrosal approaches.

Anatomic landmarks of the buccal branches of the facial nerve

The aim of this study was to classify the buccal branches of the facial nerve in relation to the parotid duct and its relevance to surgical procedures such as rhytidectomy and parotid gland surgery. In this study, 30 cadaver heads (60 specimens) were dissected. The vertical and horizontal relationships between the buccal branches of the facial nerve and tragus, and parotid duct were recorded and analyzed. The buccal branches of the facial nerve were classified into four types: Type I: a single buccal branch of the facial nerve at the point of emergence from the parotid gland and inferior to the parotid duct. Type II: a single buccal branch of the facial nerve at the point of emergence from the parotid gland and superior to the parotid duct. Type III: buccal and other branches of the facial nerve formed a plexus. Type IV: two branches of buccal branch; one superior and one inferior to the duct at the point of emergence from the parotid gland. The buccal branches of the facial nerve are very vulnerable to surgical injury because of its location in the midface. For this reason, the surgeons who are willing to operate on this area should have a true knowledge about the anatomy of these branches.

The distribution of the superficial peroneal nerve on the dorsum of the foot and its clinical importance in flap surgery

BACKGROUND

The superficial peroneal nerve (SPN) and its branches are at risk during surgical exposures. Our study aimed to demonstrate the distribution of the SPN on the dorsum of the foot to aid in surgical procedures close to this nerve.

METHODS

The SPN was dissected in 30 cadaver lower limbs (13 male and two female).

RESULTS

The variations in the distribution of the nerve were classified into seven types.

CONCLUSION

A detailed knowledge of the branching patterns of the SPN may help to decrease iatrogenic injury to this nerve.

The Distribution of the Superficial Peroneal Nerve on the Dorsum of the Foot and its Clinical Importance in Flap Surgery

BACKGROUND

The superficial peroneal nerve (SPN) and its branches are at risk during surgical exposures. Our study aimed to demonstrate the distribution of the SPN on the dorsum of the foot to aid in surgical procedures close to this nerve.

METHODS

The SPN was dissected in 30 cadaver lower limbs (13 male and two female).

RESULTS

The variations in the distribution of the nerve were classified into seven types.

CONCLUSION

A detailed knowledge of the branching patterns of the SPN may help to decrease iatrogenic injury to this nerve.

Multiplicity of the variations in ventral branches of abdominal aorta

Numerous variations of the ventral branches of the abdominal aorta were observed during routine dissection of the abdominal region in a 63-year-old male cadaver in the Department of Anatomy at Ege University Medicine Faculty. The branches of the celiac trunk were arising from two different trunks as the upper and below ones. The trunk at the upper was gastrophrenic trunk and the trunk at the below was hepatosplenic trunk. The superior mesenteric artery arose from the front of the abdominal aorta just below the hepatosplenic trunk. The relations of the right testicular artery was also unusual. Although the variations of the abdominal aorta branches are common the present case is interesting because of the multiplicity of the variations. The knowledge of these variations could be useful for clinicians for recognition and protection.

Anatomic Guides to Precisely Localize the Zygomatic Branches of the Facial Nerve

Descriptions of superficial anatomic landmarks for the identification of the zygomatic branches of the facial nerve, and their relevance for plastic surgery, are lacking in the literature. This paper provides such a description and discusses its relevance to facial surgery.

MATERIALS AND METHODS

Sixty-six specimens, including the parotid region, from 33 adult cadavers were dissected and studied. All specimens were fixed in formaldehyde, and the superficial tissues were removed and the zygomatic branches of the facial nerve, the parotid gland, the tragus and the lateral palpebral commissure were identified. The vertical and horizontal relationships were recorded and analyzed.

RESULTS AND CONCLUSIONS

A total of 69.7% of the cadavers had two branches, 25.8% had three branches, and 4.5% had a single zygomatic branch. The mean horizontal distance of the zygomatic branch (the most upper one) as it emerged from the anterior border of the parotid gland and the tragus was 30.71 mm, whereas the mean vertical distance of the zygomatic branch from the midpoint between the tragus and the lateral palpebral commissure was 19.29 mm. The branching patterns with the buccal branches were reported. There were no statistical differences between the left and right sides or between the sexes. The zygomatic branches of the facial nerve were always under the oblique line between the tragus and the lateral palpebral commissure and have a close relationship with the buccal branches of the facial nerve under this anatomic landmark. Application of the results in facial surgery is discussed.

The Anatomic Barriers in the Coronary Sinus: Implications for Clinical Procedures

BACKGROUND

Coronary sinus (CS) catheterization is often used in cardiac resynchronization therapy. Failure to enter the CS is the most common reason for LV pacing lead implant failure.

METHODS

We evaluated the anatomic barriers, Thebesian and Vieussens valves, the CS and its tributaries in 52 adult human cadaver hearts.

RESULTS

The average diameter of CS ostiums was 9.47 mm. In 20 of the hearts heavier than 300 g, the average CS os diameter was 10.76 mm, whereas in the remaining hearts was 8.72 mm (p<0.005). The Thebesian valves were observed in 35(67%) of the hearts. In 39(75%) of the hearts Vieussens valves were observed and noted that 6(11%) of them were qualitatively well developed and 33(63%) diminutive. Twenty cases (38%) had 3 vein branches, 19(37%) had 4 branches, 6(11%) had 5 branches, 6(11%) had 2 branches and 1(2%) had 6 branches between great and middle cardiac veins. The anatomic barriers in coronary sinus i.e., Thebesian and Vieussens valves and their branchings were evaluated and found optimal, suboptimal and worst for catheterization in 33, 15 and 4 Thebesian valves; 40, 8, 4 Vieussens valves, respectively. The coronary sinus tributaries between great and middle cardiac veins were found to be optimal, suboptimal and worst for catheterization in 88, 60 and 38 veins, respectively.

CONCLUSIONS

Careful evaluation of anatomic barriers is important for treatment success. Thus, knowledge of these functional anatomic features and barriers allows for better utilization of the human coronary sinus for diagnostic and therapeutic purposes.

The variations of the sensory branches of the superficial peroneal nerve course and its clinical importance

BACKGROUND

Although the sensory branches of the superficial peroneal nerve (SPN) have different anatomical variations that are of clinical importance, little is known about their anatomic courses, branching patterns, or relationships to palpable osseous landmarks.(1,3) A detailed knowledge is necessary for surgical exposures about the foot and ankle, arthroscopic procedures, ankle block anesthesia, and SPN block for leg venography.

METHODS

Thirty lower cadaver limbs were dissected to assess the anatomic properties and the variations of the sensory branches of the SPN.

RESULTS

Three distinct branch patterns were determined. In Type 1 (63.3%), the nerve penetrated the crural fascia 80.15 +/- 17.80 mm proximal to the intermalleolar line and then divided into the intermediate dorsal cutaneous nerve (IDCN) and the medial dorsal cutaneous nerve (MDCN) (classic type). In Type 2 (26.7%), the IDCN and MDCN arose independently from the SPN. In Type 3 (10%), the SPN penetrated the crural fascia 101.14 +/- 70.27 mm proximal to the intermalleolar line as a single branch. This single branch had a similar course to the MDCN. Measurements in this study were obtained from palpable bony reference landmarks.

CONCLUSION

Detailed knowledge about the SPN, IDCN, and the MDCN may decrease the damage to these nerves during operative procedures near the foot and ankle.

Clinical importance of the muscular arch of the axilla (axillopectoral muscle, Langer's axillary arch)

The muscular arch of the axilla is described in a male cadaver on the left side. The condition may be the result of a factor affecting the intrauterin development. Because this muscular arch causes difficulties in staging lymph nodes, axillary surgery, thoracic outlet syndrome, shoulder instability or cosmetic problems, it should be kept in mind for axillary pathologies.