Patellar bone stock after extra-articular knee resection preserving extensor mechanism: A cadaveric study

OBJECTIVE

This study aimed to evaluate the thickness of the remaining patellar bone stock following extra-articular knee resection (EKR) preserving the extensor mechanism in human cadaveric knee joints.

METHODS

A total of 14 human cadaveric knee joints (8 men and 2 women) were dissected, and the patellar thickness from the joint capsule insertion to the anterior cortex of the patella was measured using an electronic caliper. The mean age of the cadavers was 37 years (range=28-50). Measurements were performed by an anatomist and an orthopedic surgeon. As the total number of the cadavers was not enough to show the patellar thickness with sampling (sex and age), we endeavored to supplement the content with magnetic resonance images (MRI). Accordingly, the patellar bone thickness was also measured on axial MRI scans of 100 adult and 25 pediatric knees of patients (71 women and 54 men; mean age=36 years; age range=7-67 years) admitted to our hospital in whom meniscal tears were suspected. The rate of specimens with remaining patellar thickness of less than 10 mm after presumed resection was evaluated. The macroscopic measurements in cadavers and MRI measurements in adult knees were compared statistically.

RESULTS

The mean thickness of the residual patellar bone of the cadaver dissections following a presumed EKR preserving the extensor mechanism was 8.2 mm (range=3.4-15.8). Additionally, in 71.4% (10/14) of the cadaveric knees, the thickness of residual patellar bone was less than 10 mm. In MRI scans, the average thickness of residual patella after presumed resection was 8.6 mm (range: 3.6-16) in adult knees and 6.9 mm (range: 3.4-10) in pediatric knees, and the residual patellar thickness less than 10 mm after presumed resection was determined in 72% of all MRI scans. Macroscopic measurements in cadaveric knees were statistically similar to MRI scan measurements in adult knees (p=0.765, Mann-Whitney U test).

CONCLUSION

Evidence from this study revealed that the thickness of the remaining patellar bone stock after EKR preserving the extensor mechanism may be low. A preoperative assessment with MRI can guide the surgeon to select the appropriate method for knee resection in order to prevent from the complications of resected patella.

Arterial vascularization patterns of the splenium: An anatomical study

The aim of this study was to provide detailed information about the arterial vascularization of the splenium of the corpus callosum (CC). The splenium is unique in that it is part of the largest commissural tract in the brain and a region in which pathologies are seen frequently. An exact description of the arterial vascularization of this part of the CC remains under debate. Thirty adult human brains (60 hemispheres) were obtained from routine autopsies. Cerebral arteries were separately cannulated and injected with colored latex. Then, the brains were fixed in formaldehyde, and dissections were performed using a surgical microscope. The diameter of the arterial branches supplying the splenium of the CC at their origin was investigated, and the vascularization patterns of these branches were observed. Vascular supply to the splenium was provided by the anterior pericallosal artery (40%) from the anterior circulation and by the posterior pericallosal artery (88%) and posterior accessory pericallosal artery (50%) from the posterior circulation. The vascularization pattern of the splenium differs in each hemisphere and is usually supplied by multiple branches. The arterial vascularization of the splenium of the CC was studied comprehensively considering the ongoing debate and the inadequacy of the studies on this issue currently available in the literature. This anatomical knowledge is essential during the treatment of pathologies in this region and especially for splenial arteriovenous malformations.

Dorsal cutaneous innervation of the hand with respect to anatomical landmarks: is there a safe zone?

OBJECTIVES

In this study, we aimed to define the borders of the triangular area between the radial and dorsal nerves on the dorsum of the hand and to determine its dimensions using measurements between anatomic landmarks.

MATERIALS AND METHODS

We statistically analyzed the relation between the distance from Lister's tubercle to the blending point of the central branches of radial and ulnar nerves and the distance between styloids on 14 hands of seven adult human cadavers (5 males, 2 females). The distances of nerve branches to vertical lines drown distally from both styloid processes were also compared with interstyloid distances to help in presuming the course of these nerves.

RESULTS

No statistical constant correlation was determined between the measurements. Neither the height of the triangular area nor the courses of both nerves seemed to be quantitatively related to any measurements between the anatomical landmarks.

CONCLUSION

Variability in these measurements in our study indicates that there is no surgical safe zone on the dorsum of the hand.

A short postgraduate anatomy course may improve the junior surgical residents' anatomy knowledge for the nerves of the inguinal region

BACKGROUND AND AIM

Inguinal hernia repair is one of the most common operations in a junior surgical resident's postgraduate training. Short recall courses can improve junior residents' anatomy knowledge and results in better surgical outcomes. We aimed to investigate the effect of a short course on anatomical competency during inguinal hernia repairs.

METHODS

During the first 25 inguinal hernia repairs, two junior residents were asked to identify iliohypogastric, ilioinguinal, and genital branch of genitofemoral nerves. Then, the residents were given a short recall course by anatomists. Afterwards, the participants were taken into an in-vivo anatomy test again. The same parameters were recorded in another 25 inguinal hernia repairs. In addition to the nerve identification records, case characteristics [body mass index (BMI < or = 25 vs. >25), hernia type (indirect vs. direct), and anesthesia used (general or regional vs. local)] were recorded.

RESULTS

Anatomy education had a clear impact on the correct identification rates for the iliohypogastric and ilioinguinal nerves. The rates increased from 70% to 90% and above. Correct identification rate for the three nerves together significantly increased from 16 to 52% following anatomy education (P = 0.006). All three nerves were identified with significantly higher success rates after anatomy education. The increase in the success rate for identification of the genital branch of genitofemoral nerve was 4-fold.

CONCLUSIONS

Short anatomy courses in specific subjects for junior surgical residents given by formal anatomists may be effective during postgraduate education. The benefit obtained in the present study for the inguinal region nerves may be expanded to more important anatomical structures, such as the recurrent laryngeal nerve in a thyroidectomy, or more complex subjects.

Arterial vascularisation of the anterior perforated substance

INTRODUCTION

The arteries of the anterior perforated substance (APS) are important due to their role in supplying blood to important internal structures such as the internal capsule, putamen and caudate nucleus. The purpose of this study was to investigate in detail the arteries of the APS.

METHODS

The arteries of the APS were investigated in 60 cerebral hemispheres from 30 adult cadaveric brains. The internal carotid arteries were cannulated and perfused with coloured latex. The branches of the middle cerebral artery (MCA) penetrating the APS were investigated. These arteries, known as the lateral lenticulostriate arteries and originating from the M1 segment, early temporal and early frontal branches of the MCA, were recorded.

RESULTS

The branches of the anterior choroidal artery, which reached the APS, were seen in all specimens. We found one to three branches that arose from the A2 segment of the anterior cerebral artery (ACA) to the APS in all hemispheres, and one to three branches that originated from the A1 segment of the ACA in 48 hemispheres. In addition, two accessory MCAs that originated from the A2 segment of the ACA were recorded as variations, and perforating branches to the APS were observed.

CONCLUSION

Serious complications like motor deficits can occur as a result of injury to the arteries of the APS. Hence, neurosurgeons performing operations such as aneurysm or insular tumour surgeries must be aware of the importance of preserving these arteries.

Lateral approach to the ankle and distal leg

Fractures of the distal tibia are usually high-energy injuries and are well known for their soft tissue complications after surgery. Various factors have been studied regarding the possibility of them reducing the incidence of such damage, including timing of surgery, staged surgery, fixation method, and surgical approach. Less invasive surgical techniques with vascularity preserving approaches were proposed as reasonable solutions to this problem. The aim of this study was to investigate the presence of minor vascular structures, which can be preserved during anterolateral approach, possibly contributing to the success of the approach. Lateral approach for the distal tibia was performed in 22 cadaver feet. The mean distance between the lateral malleolus and the superficial peroneal nerve was 12.2 cm. Two different vascular pedicles, from peroneal vessels to muscles of the anterior compartment, were 4.3 and 8.2 cm away from the lateral malleolus, respectively. We conclude that preserving greater vascularity was possible in the lateral approach for the distal tibia, placing the plate in a completely submuscular plane.

Neurovascular relationship between abducens nerve and anterior inferior cerebellar artery

We aimed to study the neurovascular relationships between the anterior inferior cerebellar artery (AICA) and the abducens nerve to help determine the pathogenesis of abducens nerve palsy which can be caused by arterial compression. Twenty-two cadaveric brains (44 hemispheres) were investigated after injected of coloured latex in to the arterial system. The anterior inferior cerebellar artery originated as a single branch in 75%, duplicate in 22.7%, and triplicate in 2.3% of the hemispheres. Abducens nerves were located between the AICAs in all hemispheres when the AICA duplicated or triplicated. Additionally, we noted that the AICA or its main branches pierced the abducens nerve in five hemispheres (11.4%). The anatomy of the AICA and its relationship with the abducens nerve is very important for diagnosis and treatment.

Callosal branches of the anterior cerebral artery: an anatomical report

Although the morphology of the corpus callosum is well defined, the arterial supply of this structure has not been comprehensively studied. To elucidate this further, 40 cerebral hemispheres from 30 adult cadaveric brains were obtained. The anterior cerebral arteries were cannulated and injected with red latex. The following were observed and documented: (1) the number, diameter, and course of the arteries supplying the corpus callosum; (2) the territories vascularized by these arteries; (3) any variations of the callosal arteries. Short callosal arteries were present in 58 hemispheres (96.6%) and supplied the superficial surface of the corpus callosum along its midline and were a primary arterial source to this structure. Long callosal arteries were found in 28 hemispheres (46.6%) and contributed to the pial plexus. The cingulocallosal arteries were present in all hemispheres and supplied the corpus callosum, cingulate gyrus, and also contributed to the pericallosal pial plexus. The recurrent cingulocallosal arteries were present in 17 hemispheres (28.3%) and also contributed to the pericallosal pial plexus. The median callosal artery, an anatomical variation, was present in 10 brains (33.3%). This vessel supplied the corpus callosum and the cingulate gyrus. The aim of the present study was to provide a detailed description of the arteries supplying the corpus callosum for those who encounter these vessels radiologically or surgically.

The innervation of patella: anatomical and clinical study

As much interest has been focused on afferent innervation of knee than that of patella, there are few articles about patellar innervation. But in clinical practice anterior knee pain due to patellar disorders is a quite frequent problem. Our aim was to review the innervation pattern of patella and to give the topographic anatomy of the nerves. We dissected 30 knees of 15 formaldehyde-fixed cadavers. Two nerves from vastus medialis and lateralis were found to reach patellar edge. Apart from these, we were unable to find any other neural structures around patellae. Mean distances between the tuberosity of the tibia and medial and lateral nerve entry points were 90.1(range 74-102) and 96.3 mm (range 76-109), respectively. The angles between lines which join the entry points of nerves and vertical line to the center point of patella were measured in frontal plane. It was approximately 60 degrees medially and 40 degrees laterally. To confirm that these nerves are patellar pain afferents, we performed a local anesthesia test in 32 knees of 20 patients with patellofemoral pain. Clinically, there was a significant difference between the visual analogue scale (VAS) scores before and after local anesthetic injections (p<0.01). Previous studies have emphasized especially the medial innervation. We found that both superomedial and superolateral nerves were important for patellar innervation. We described precisely the entry points of these nerves to patella for selective denervation.

Evaluation of the anterior and posterior ethmoidal canal by computed tomography

AIM

To examine the anatomy, length and angulation of the anterior and posterior ethmoidal canals (AECs and PECs) using computed tomography (CT), and to determine the anatomical landmarks in which the canals are expected to be seen in transverse and coronal planes.

MATERIALS AND METHODS

CT images of 150 patients were analysed. One, 2, and 3 mm thick sections were obtained separately in axial and coronal images. The frequency of visualization of the AECs and PECs, and if present, a third canal, was noted. The course and the angulation of the AEC and the PEC in transverse and coronal planes were recorded. On axial sections the distance between the AEC and PEC and the previously defined landmarks were measured. On coronal images, the distances were calculated from the thickness of the cross-section and the number of sections between the various structures.

RESULTS

The AEC was identified as a separate canal in 84% of patients, and was embedded in the ethmoid roof in 16%. The PEC was seen as a separate canal in 8% and was present in the ethmoid roof in 92%. On the 1 mm thick coronal and transverse sections, a third canal was identified at the junction of the middle and posterior third of the AEC-PEC distance in both of the images. The average lengths of these canals were 4-12 mm (mean 8.2 mm) for the AEC, and 2-13 mm (mean 7.6 mm) for the PEC.

CONCLUSIONS

To avoid the complications that can develop during endoscopic sinus surgery; the course, length and the angulations of the anterior and posterior ethmoidal arteries and their canals can be identified by CT in standard positions if a sufficiently thin section thickness is used. The present study has shown the exact CT localization of the AECs and PECS, which are frequently overlooked when evaluating para-nasal sinuses.