Anatomical Variations of the Musculocutaneous Nerve in the Human Fetus.

OBJECTIVES: Knowing the motor branches and variations of the musculocutaneous nerve to the muscles along its course will facilitate the treatment of flexor spasticity and supracondylar fractures of the humerus in order to minimize nerve lesion. In fetal cadavers, the purpose of our study was to determine the number and course of the formation variations and motor branches of the musculocutaneous nerve. The significance of studying fetal nerve variations is due to injury to the brachial plexus roots during birth. METHODS: Our study was conducted using the anatomical dissection technique on 102 upper limbs from 51 fetuses ages ranged from 17 to 40 weeks. Throughout its course, the variations and motor branches of the musculocutaneous nerve were analyzed. RESULTS: In 13.7% of cases, the musculocutaneous nerve did not pierce the coracobrachialis. The musculocutaneous nerve gave the muscles 1-3 motor branches. Additionally, motor branches terminated with 1-7 fringes. The biceps brachii motor branches of the musculocutaneous nerve were typed. Accordingly, 15.6% were type 1A, 3.9% were type 1B, 35.4% were type 1C, and 19.6% were type 1D. It was determined that 23.5% of the extremities were type 2 and that 1.9% were type 3. The distance between the musculocutaneous nerve's motor branches and the acromion was proportional to the arm's length. There were no statistically significant differences between the sides and genders for any measurement. CONCLUSIONS: Our study's findings will aid in the diagnosis and treatment of pediatrics, orthopedics, surgical sciences, and radiology conditions. It reduces the risk of iatrogenic injury and postoperative complications. We also believe that our research will serve as a resource for anatomists and other scientists.

Innervation Patterns of the Psoas Major and Iliacus Muscles in Fetal Cadavers.

AIM: We aimed to investigate in detail the innervation patterns of the psoas major and iliacus in fetal cadavers. MATERIAL AND METHODS: The innervation patterns of 94 psoas major and 94 iliacus belonging to 47 fetuses (28 males, 19 females) aged between the 18th-40th gestational weeks in the laboratory of the Department of Anatomy at the Faculty of Medicine were examined. The nerve branches innervating the psoas major and iliacus and the origin levels of these branches were determined. The branches innervating the psoas major and iliacus were classified as L1, L1-L2 level, L2, L2-L3 level, L3, L3-L4 level, L4 and femoral nerve according to the levels at which they originate from the spinal nerves. RESULTS: It was determined that the psoas major was innervated by the ventral branches of the L1-L4 spinal nerves and the femoral nerve. It was observed that the iliacus was innervated only by the femoral nerve. The mean number of branches innervating each psoas major and iliacus was determined as 4.69±2.02 and 3.07±1.14 respectively. It was observed that the branches innervating the psoas major originated at least at the level between the L1-2 spinal nerves and most at the level between the L2-3 spinal nerves. CONCLUSION: The spinal nerves innervating the psoas major are at risk of injury during lateral transpsoas surgery, lateral discectomy, and spinal fusion surgery. Therefore, it may be useful for surgeons to know the innervation patterns of the psoas major in surgical interventions to be performed in this region. Furthermore, it will be useful for surgeons to know the innervation of the iliacus in various surgical interventions on the iliac fossa.

An Investigation of the Morphometry and Localization of the Foramen Ovale and Rotundum in Asymptomatic Individuals and Patients with Trigeminal Neuralgia.

AIM: To compare the morphometric characteristics of the foramen ovale (FO) and foramen rotundum (FR), and their localization in the middle cranial fossa on the head and neck computed tomography images of patients with trigeminal neuralgia (TN) and asymptomatic individuals. MATERIAL AND METHODS: The FO and FR length, width, and area parameters were examined in 158 asymptomatic individuals and 19 patients with TN. Their localization in the middle cranial fossa was determined according to the sagittal (y) axis passing through the middle of the dorsum sella and connecting the foremost point and the rearmost point of the skull and the transverse (x) axis passing through the middle of this axis. In the comparison with asymptomatic individuals, data on the painful side of patients with trigeminal neuralgia were used. RESULTS: The mean width of the FO and its distance from the transverse axis were determined to be 3.36 ± 0.79 mm and 1.44 ± 0.39 mm in asymptomatic individuals and 2.88 ± 0.83 mm and 1.23 ± 0.45 in TN patients, respectively. These FO parameters were statistically significantly smaller in patients with TN. In asymptomatic individuals, while the mean width of the FR was determined to be 2.05 ± 0.48 mm, the mean length was 2.14 ± 0.47 mm, and its distances to the transverse axis and sagittal axis were found to be 2.65 ± 0.35 mm and 1.96 ± 0.25 mm, respectively. In patients with TN, while the mean width of the FR was revealed to be 1.77 ± 0.46 mm, the mean length was 1.78 ± 0.42 mm, and its distances to the transverse axis and sagittal axis were found to be 2.33 ± 0.40 mm and 1.87 ± 0.16 mm, respectively. These FR parameters were statistically significantly smaller in patients with TN. CONCLUSION: Statistically significantly smaller dimensions of the FO and FR and their distances to the sagittal and transverse axes in patients with TN suggested that they might be among the causes of TN.

The development of the medial longitudinal arch in the intrauterine period.

In this study, we aimed to reveal whether the medial longitudinal arch is formed in the intrauterine period and the structural features of the medial longitudinal arch. The study was conducted on 146 feet of 73 fetuses (38 male, 35 female) aged between 15 and 40 weeks of gestation. The fetuses were grouped by trimesters. The footprints taken were photographed with a millimeter ruler, and the development of the medial longitudinal arch was examined on footprints based on the Clarke index, Chipaux-Smirak index, and Staheli index. In Clarke index and Staheli index, it was observed that the arch height was normalized in the transition from the second trimester to the third trimester, the arch decreased in the transition to full-term, and the rate of pes planus increased. All indices detected pes planus by 81.81% in the full-term period. The rate of pes planus determined according to Clarke index and Staheli index, especially in the third trimester period, was 6.94% and 11.11%, respectively. We have provided a perspective on how the development of the medial longitudinal arch is shaped in the intrauterine period. Based on the results of study, we consider that the data on the medial longitudinal arch, especially in the third trimester period, may be more significant. In the evaluations made from the footprints of premature infants in the intrauterine third trimester period in the future, a study, in which infants detected with pes planus can be followed up and the development of their medial longitudinal arch is evaluated, can be conducted.

Anatomical variations of the extensor tendons of the fetal thumb.

PURPOSE: The extensor pollicis longus (EPL) and brevis (EPB) and abductor pollicis longus (APL) are muscles located in the posterior compartment of the forearm. These muscles allow the thumb to move independently from the other four fingers by attaching to the thumb separately. This study's goal was to investigate the tendon variations and insertions of these muscles. METHODS: Our study was conducted on 43 fetal cadavers (86 upper extremities) aged between 17 and 40 weeks of gestation. This study investigated the tendon numbers and insertions of the EPL, EPB, and APL. RESULTS: The tendon numbers of the EPL and EPB were observed to range between 1 and 2, and the tendon numbers of the APL ranged between 1 and 5. The EPL was found to insert into the distal phalanx via the dorsal aponeurosis in all extremities. It was observed that the EPB tendons inserted into the proximal phalanx, distal phalanx, and dorsal aponeurosis. It was determined that the APL tendons inserted into the basis of the first metacarpal, abductor pollicis brevis, opponens pollicis, and trapezium bone. CONCLUSION: Knowing the tendon variations and insertions of the EPL, EPB, and APL muscles during the fetal period will be useful in planning treatments to correct the congenital thumb anomalies and the loss of function after injury.

Morphometric Development of the Mandible in Fetal Cadavers.

PURPOSE: The aim of this study is to present reliable data by measuring the morphometric properties of the mandible in the fetal period. METHODS: A study was performed on mandibles of 35 fetuses (18 male fetuses and 17 female fetuses), aged between 21 and 40 weeks of gestation. Fetuses were examined in 3 groups according to their developmental stages: 2nd trimester, 3rd trimester, and full-term. Morphometric measurements were performed for both the right and left sides of each mandible. The measurements of the mental foramen were performed using a digital caliper, and other measurements were performed using the ImageJ program. The data obtained were analyzed using the SPSS 20 for Windows program. RESULTS: There was no significant gender difference for all parameters. When the parameters were compared by the trimesters, no significant difference was determined in the 2nd trimester - 3rd trimester, 3rd trimester-full-term, and second trimester - full-term comparisons of the angle of the mandible, and there was a significant difference in all other parameters (P < 0.05). According to the trimesters, all parameters, except the angle of the mandible, increased naturally with the development of the mandible. It was observed that the angle of the mandible decreased from the 2nd trimester to the 3rd trimester and increased from the 3rd trimester to the full term. When the right and left measurements were compared, no significant difference was found for all parameters in both general and trimester groups. CONCLUSION: The present study includes fetal mandibular parameters that have not been reported elsewhere. It is thought that the obtained data will contribute to the determination of anomalies, pathologies, and variations.

A case with multiple accessory foramina of mandible in a fetus.

It is aimed to better recognize the mandibular variations by understanding the diversity and positions of accessory foramina better. Accessory formations on a full-term fetal mandible dissected for a mandibular study were examined under a microscope. To observe these formations more clearly, they were photographed with the help of a camera and microscope. In one of the mandibles dissected for a fetal mandibular study, a lateral accessory foramen (LAF1) was detected in the right half just near the mental foramen, and also a medial accessory foramen (MAF1) was detected over the mandibular foramen. In the left half, on the lateral surface relative to the mental foramen, one in the medial (LAF3) and one just above it (LAF2), and last one is near to the ramus of mandible (LAF4), three lateral accessory foramina, were detected. Again, a medial accessory foramen just above the left mandibular foramen (MAF3), and another foramen is near to mandibular symphysis (MAF2), also two medial accessory foramina on the lateral surface were detected. Detection and recognition of such variations are quite important for clinicians in the diagnostic methods and prevention of possible surgical complications.

Morphometric development of the tongue in fetal cadavers.

PURPOSE: The tongue is a specific organ for the sense of taste. It consists of the striated muscle and mucous membrane. Furthermore, it helps the functions of speech, chewing, and swallowing. In this study, we aimed to reveal some morphometric properties of the tongue in fetal cadavers. METHODS: The study was conducted on a total of 45 fetal tongues (25 male tongues, 20 female tongues) aged between 17 and 40 weeks. The fetuses were divided into three groups as trimester II, trimester III, and full term. For each tongue, the length, width, area, free tongue length, and the terminal sulcus angle were measured using Image J program. The free tongue length/tongue length ratio was examined. RESULTS: The obtained data were compared according to the trimester groups and genders. It was determined that the tongue length, width, area, and free tongue length increased during the trimesters and that there was no significant difference in the terminal sulcus angle and the free tongue length/tongue length ratio between the trimesters. No significant difference was found in all parameters between the genders. CONCLUSIONS: This study presented significant data on morphometric development of the tongue. These data are thought to be useful for determining the anomaly and variations of the tongue.

Anatomical relation between sciatic nerve and piriformis muscle and its bifurcation level during fetal period in human.

PURPOSE: The aim of this study is to determine the morphometric development, location and variant formations of the sciatic nerve using anatomic dissection method during the fetal period. METHODS: Sciatic nerves of 200 human fetuses (103 males and 97 females) aged between 9 and 40 weeks of gestation were studied bilaterally. The bifurcation level of the sciatic nerve to its terminal branches was evaluated with respect to popliteal fossa. Then the length of the sciatic nerve, starting from where it leaves the piriformis muscle till the bifurcation point of the nerve, and its width at the point where it leaves infrapiriforme foramen and its width at the bifurcation level were measured. We also measured the distance of the sciatic nerve to the ischial tuberosity, the greater trochanter and the intergluteal sulcus. Mean values and standard deviations of all parameters according to trimesters were calculated. RESULTS: We found that all parameters increase with age during the fetal period (P < 0.05). Parameters do not show any significant differences between sexes (P > 0.05). In our analysis, we observed that in 98 % of the cases (on the right and the left side) the sciatic nerve leaves the pelvis below the piriformis muscle. The remaining cases (2 %) are variant formations. CONCLUSION: We believe that our study will be useful for better understanding of sciatic nerve development and it may contribute to future studies in obstetrics, orthopedics and fetal pathology. Knowledge of variant formations of the sciatic nerve, its bifurcation level and its relation with neighboring structures may be important for blockade of the nerve in newborn surgeries.

Motor branching patterns of the ulnar nerve in the forearms of fetal cadavers.

PURPOSE: The aim of this study was to investigate the branches of the ulnar nerve given to forearm muscles [flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP)] and typing of ulnar nerve according to distribution of these branches to the muscles. METHODS: From the collection of Anatomy Department Laboratory, Faculty of Medicine, Suleyman Demirel University, 116 upper limbs of fetuses showing no external anomaly and aging between 12th and 40th weeks of pregnancy, were included in this study for anatomical dissection. Parameters about the branching of fetal ulnar nerve were set as follows: branch/branches to FCU muscle and branch/branches to FDP muscle. RESULTS: Ulnar nerve was typed according to number, sequence, and distribution of motor branches of ulnar nerve. As a result of this typing, eight type branching model of ulnar nerve was confirmed. CONCLUSIONS: Our study is critically important for implementing successful surgical interventions and minimizing complications especially in ulnar nerve and forearm muscles surgery also in nerve replacement on this area.

Anatomy and variations of palmaris longus in fetuses.

The aim of this study was to assess the absence of the palmaris longus, the proportion of the lengths of tendon and muscle belly, the development of the tendon and the belly during the fetal period, look for any difference between sides and gender. Fifty-eight spontaneously aborted human fetuses (26 female, 32 male, 116 upper extremities) were studied. The presence or absence of the palmaris longus was determined. The lengths of the belly and tendon were measured, and belly/tendon length ratio was calculated. Correlation with gestational age, body side and gender were studied. The muscle was absent in 44 forearms (37.93%; 20 right side, 34.48%; 24 left side, 41.38%); being bilateral in 19 of 58 fetuses (32.76%) and unilateral in six (10.34%). The unilateral absence rate was higher on the left side with a statistically significant difference. The absence of palmaris longus was more common in females, and the difference was statistically significant. The belly/tendon length ratio was 1.04 ± 0.35 on the right side and 1.09 ± 0.3 on the left. It did not show any difference according the fetal age. A sound knowledge on the anatomy and variations of palmaris longus is of great importance during surgical interventions; because it is the first choice for tendon grafts, by the virtue of its structure and function. Thus, this study is of academic interest for anatomists and hand surgeons alike.