Variants of latissimus dorsi with a perspective on tendon transfer surgery: an anatomic study.

BACKGROUND: The latissimus dorsi (LD) is often used for tendon transfers to treat massive irreparable posterosuperior rotator cuff tears. The operation requires the LD tendon to be mobilized to reduce tension on the tendon. In that respect, any connection between the LD tendon and contiguous muscles may hamper tendon mobility and affect the surgical outcome. The goal of this study was to document the occurrence of connections between the LD and adjacent muscles and nerves. METHODS: We studied the scapular region on 48 embalmed cadavers. The skin and superficial fascia were removed according to Cunningham's manual of dissection, and the muscle was exposed. RESULTS: It was found that the LD and teres major (TM) muscles are connected by muscle fibers in 10% of the cadavers studied. Another vital discovery was that in some cadavers, the LD tendon was penetrated by a nerve. CONCLUSION: Fascial connections between the LD and TM are well known, but these muscle links are comparatively unusual. From the results of this study, one should pay particular attention to muscle links between the LD and TM during dissection of the LD for transfer. It can also be suggested that during transfer surgery, the LD tendon should be cautiously examined for the possibility of a nerve penetrating it.

A Cephalometric Analysis on Magnitudes and Shape of Sella Turcica.

Familiarity with the shape and dimensions of sella turcica is important to recognize and manage pathological conditions of pituitary gland as well as for orthodontic treatment planning. The present study aims to describe the morphology and dimensions of sella turcica from Indian population, using lateral cephalograms to set a reference data for comparison among different races. The study used 36 lateral skull radiographs of both sexes between age group of 13 to 18 years. Shape of sella turcica was noted by visual inspection. Length, height anterior, height median, height posterior, distance between frontonasal suture and mental spine to midpoint of posterior clinoid process, and tuberculum sella were measured using digital vernier caliper with reference to Frankfort line. The results of the study revealed that mean length, height anterior, height median, height posterior were larger in females than in males. The morphological types identified include pointed posterior clinoid process with rounded hypophyseal fossa, hooked posterior clinoid process with rounded hypophyseal fossa, hooked posterior clinoid process with flask-shaped hypophyseal fossa. These observations would be beneficial for the clinicians and orthodontists to design treatment planning in pathology of pituitary gland and in correcting dentofacial anomalies.

Arterial supply to the soleus muscle: an anatomical study with emphasis on its application in the pedicle flap surgery.

PURPOSE: To study the various patterns in the extra muscular part of arterial supply to the soleus muscle. METHODS: The study was carried out using 38 adult cadaveric lower limbs which were available from the Department of Anatomy of our institution. The vascular branches to the soleus were identified and traced till their point of entry into the soleus. These were considered as extramuscular branches (EMB) to the soleus. The distances of first and last branches from each artery were measured from the apex of head of fibula to their point of entry into the soleus and were expressed as proportion to the length of soleus. RESULTS: The present study observed that the soleus muscle is supplied by EMB of popliteal, posterior tibial and peroneal arteries. In 42.1% cases, there was no direct EMB from the popliteal artery to the soleus. The EMB of popliteal artery were located between 3.2 and 24.6% of the length of soleus. The EMB from the posterior tibial and peroneal arteries were located between 6.8-97.1% and 5.7-94.9% of the length of soleus, respectively. The proximal 25% of length of soleus received EMB from all the three arteries. CONCLUSIONS: The present study has provided additional information on the various patterns in the extra muscular part of arterial supply to the soleus muscle. This knowledge is important to the plastic and orthopedic surgeons while performing the pedicle flap surgeries. Our opinion is that the proximally based soleal muscle flaps are more beneficial in the surgical practice.

Morphometric study of the medial orbital wall emphasizing the ethmoidal foramina.

PURPOSE: Ethmoidal foramina on the medial orbital wall show a higher incidence of variation. Surgeons performing endonasal, anterior cranial fossa and medial orbital wall surgeries must be aware of these variations as they are a source of hemorrhage and also serve as landmark in proximity to the orbital apex. AIM: The present study aims to describe the morphometric distances of various ethmoidal foramina between anterior lacrimal crest to optic canal in south Indian dry human skulls. MATERIALS AND METHOD: The study was done on 44 adult dry human skulls. The occurrence of Ethmoidal foramina was noted by direct inspection. The distance of Ethmoidal foramina from anterior lacrimal crest to optic canal was measured with the help of ruler, probe and magnifying glass. RESULTS: The Posterior ethmoidal foramina were found in all 44 skulls bilaterally. Middle ethmoidal foramen was present in 12 and 13 skulls on right and left, respectively. Anterior ethmoidal foramen was found in 38 and 37 skulls on right and left, respectively. The distance between anterior lacrimal crest (ALC) and posterior lacrimal crest (PLC) was in the range of 3-8 mm and that of ALC to anterior ethmoidal foramen was in the range of 24-30 mm. The range of distance between anterior ethmoidal foramen to posterior ethmoidal foramen was 9-17 mm and that between posterior ethmoidal foramen to optic canal was 5-13 mm. CONCLUSION: These observations would help to predict the anatomical variations in the position of ethmoidal foramina with respect to anterior and posterior lacrimal crest and ensure the safe and precise performance of medial orbital wall surgeries to avoid injuries to the important neurovascular bundles passing through various foramina and fissures.

Morphometry of the thyroid cartilage, epiglottis and piriform sinus: An anatomical study.

Background: The goal was to measure the piriform sinus, epiglottis, and thyroid cartilage in our sample population. Methods: This study included 22 adult embalmed cadavers available in the Department of Anatomy. Dimensions were measured using a digital Vernier caliper. Results: The mean height of the thyroid laminae was 27 ± 1.4 mm at the right side and 25.5 ± 1.4 mm at the left side. Mean width of the thyroid lamina was 27.1 ± 1.3 mm at the right side and 27.4 ± 0.9 mm at the left side. The mean thickness of thyroid cartilage was found to be 4.4 ± 0.4 mm and 3.9 ± 0.5 mm over the right and left sides. The mean length, width and thickness of the epiglottis were 29.1 ± 0.5 mm, 22.2 ± 0.6 mm and 2.6 ± 0.3 mm correspondingly. The height, width and thickness of the right piriform sinus were 25 ± 0.5 mm, 14.2 ± 0.5 mm and 12.6 ± 0.5 mm, the same parameters were 25.3 ± 1.3 mm, 15.1 ± 0.7 mm and 13.3 ± 0.4 mm for the left side. Conclusions: The height and thickness of the thyroid cartilage were greater on the right side than on the left side (p<0.05). It was statistically observed that the width and thickness were greater on the left side than on the right side (p < 0.05). The data about the height, width and thickness of the thyroid cartilage, epiglottis and piriform sinus are essential during the laryngeal and other neck surgeries. They guide in the preoperative positioning, predicting the difficulty of intraoperative exposure and retractor pulling.

Anatomical and morphometric analysis of accessory infraorbital foramen.

The aim of the present study was to analyze the anatomical and morphometric variation in shape, frequency of occurrence, direction, and position of accessory infraorbital foramen (AIOF) in relation to infraorbital foramen (IOF) in cadaveric dry skulls to minimize clinical complications and aid in surgical maneuvering in the maxillofacial region and implementing the regional block anesthesia. The IOF is an important anatomical landmark in these surgical manipulations. Because there is limited literature available on AIOF, which transmits accessory branch of the infraorbital nerve, the present study was designed. In the current study, 45 human dry skulls and 20 disarticulated maxillae have been used irrespective of sex. The other parameters included measuring the distance of AIOF from anterior nasal spine, frontomaxillary suture, infraorbital margin, IOF, and zygomaticomaxillary suture. The transverse and vertical diameter of foramen was also noted. All these measurements were taken using a digital caliper. The result of our study reveals that the presence of AIOF is more on the right side compared with the left side. Because the presence of accessory infraorbital nerve needs to be taken care of during maxillofacial surgical interventions, knowledge regarding the presence of AIOF should be taken into consideration for preoperative evaluation.

Variant facial artery in the submandibular region.

Facial artery has been considered to be the most important vascular pedicle in facial rejuvenation procedures and submandibular gland (SMG) resection. It usually arises from the external carotid artery and passes from the carotid to digastric triangle, deep to the posterior belly of digastric muscle, and lodges in a groove at the posterior end of the SMG. It then passes between SMG and the mandible to reach the face after winding around the base of the mandible. During a routine dissection, in a 62-year-old female cadaver, in Kasturba Medical College Mangalore, an unusual pattern in the cervical course of facial artery was revealed. The right facial artery was found to pierce the whole substance of the SMG before winding around the lower border of the mandible to enter the facial region. Awareness of existence of such a variant and its comparison to the normal anatomy will be useful to oral and maxillofacial surgeons.

Unique distribution by the peroneal nerves: a case report.

PURPOSE: Among the branches of common peroneal nerve, the superficial peroneal provides cutaneous innervation to major part of the dorsum of the foot and deep peroneal nerve supplies the skin over the first interdigital cleft region. METHODS: The present rare case was observed during routine dissection of leg for undergraduate students, in a 52-year-old male, formalin fixed cadaver. RESULTS: The superficial peroneal nerve provided solely motor branches to peroneus longus and brevis, whereas cutaneous branches were provided by deep peroneal nerve. In the lower one-third of the leg deep peroneal nerve divided into medial and lateral branches. The medial branch supplied tibialis anterior and the lateral branch supplied skin of medial three and half toes. Moreover, the sural nerve supplied the skin of lateral one and a half toes. CONCLUSION: Awareness of this type of variations in the course of nerves helps to alert the surgeons when there are complaints of atypical or unique pain in that particular region.

Thickness and width of the menisci of adult knee joint: a descriptive cross-sectional observational study in cadavers.

Background: The goal was to determine the thickness and width of the knee joint meniscus at their different regions. The objective was to compare the dimensions at these regions and over the right- and left-sided specimens. Methods: The present study included 50 adult cadaveric knee joints, and 100 menisci (50 medial menisci and 50 lateral menisci) were studied. The meniscus was distributed into anterior, middle and posterior parts. Thickness and width at the mid-point of these three parts were determined by using the Vernier caliper. Results: The breadth of the medial meniscus was 8.38 ± 1.64 mm, 7.68 ± 1.92 mm and 13.93 ± 2.69 mm at the anterior, middle and posterior one-third regions. Same measurements for the lateral menisci at these regions were 9.84 ± 1.78 mm, 8.82 ± 2.01 mm and 10.18 ± 2.23 mm, respectively. The thickness of the medial meniscus was 4.49 ± 0.78 mm, 4.07 ± 0.81 mm and 4.79 ± 0.93 mm at these regions. The lateral meniscus thickness was 3.82 ± 0.69 mm, 4.43 ± 0.98 mm and 4.36 ± 0.8 mm, respectively. Conclusion: It is believed that this data is enlightening to the arthroscopic surgeon during the meniscus transplantation either by using synthetic material or allograft as the proper sizing of the meniscus is important to prevent complications due to inaccurate sizing.

Dimensions of pes anserinus of the lower extremity, an anatomical study with its surgical implications.

The reconstructive surgeries utilize pes anserinus (PA) tendons, because of their lesser post-operative clinical deficits and donor site morbidity. These surgeries require anatomical knowledge about the extent of PA formation. The goal of this study was to determine the length and width of the PA formation. The objectives were to measure the distance of its upper limit, lower limit, and vertical distance from the tibial tuberosity (TT). The present descriptive cross sectional study included 53 embalmed cadaveric lower extremities. The upper and lower limits of PA were exposed with the careful dissection. Measurements of the dimensions were performed with the help of a digital vernier caliper (Mitutoyo Co., Kanagawa, Japan). The PA length, width, distance of its upper limit, lower limit, and vertical distance of it from the TT were 47.4±13.3 mm, 37.3±7.2 mm, 47.6±12.5 mm, 54.6±10.4 mm, and 39.1±14.2 mm, respectively over the right extremity. The same measurements were 46.3±14.7 mm, 39.1±9.4 mm, 39.1±5.9 mm, 49.5±8.2 mm, and 36.4±12.1 mm, respectively for the left extremity. The extent of PA was observed to be extremely variable. The preoperative knowledge about the dimensions of PA will help the plastic and orthopedic surgeon put the accurate skin incision, decreasing the donor site morbidity and biomechanical instability of the PA grafts. We suggest that, preoperative ultrasound measurement of the PA may help the operating surgeon to prevent the complications like injury to the infrapatellar branch of saphenous nerve.

A case of inferior alveolar nerve encircling the arteria maxillaris.

Here we report a case of inferior alveolar nerve (IAN), which had variability in its formation. IAN was formed by dual roots, which were branching out from the posterior division of mandibular nerve. The observed roots were forming a loop around the pterygoid part of arteria maxillaris (MA). One of the roots was superficial to the MA and the other was deep to it. It is believed that this type of morphological variation in the formation of IAN can have clinial implications, which include compression by adjacent structures and nerve entrapment. The knowledge of this variation is important to anaesthesiologists and dentists, while administering local anaesthesia. This is also enlightening to the maxillofacial surgeons, neurologists and radiologists.

Duplication of falx cerebelli, occipital sinus, and internal occipital crest.

The incidence of variations of falx cerebelli was studied in 52 adult cadavers of south Indian origin, at Kasturba Medical College Mangalore, after removal of calvaria. In eight (15.4%) cases, we observed duplicated falx cerebelli along with duplicated occipital sinus and internal occipital crest. The length and the distance between each of the falces were measured. The mean length of the right falces cerebelli was 38 mm and the left was 41 mm. The mean distance between these two falces was 20 mm. No marginal sinus was detected. Each of the falces cerebelli had distinct base and apex and possessed a distinct occipital venous sinus on each attached border. These sinuses were noted to drain into the left and right transverse sinus respectively. After detaching the dura mater from inner bony surface of the occipital bone, it was noted that there were two distinct internal occipital crests arising and diverging inferiorly near the posterolateral borders of foramen magnum. The brain from these cadavers appeared grossly normal with no defect of the vermis. Neurosurgeons and neuroradiologists should be aware of such variations, as these could be potential sources of hemorrhage during suboccipital approaches or may lead to erroneous interpretations of imaging of the posterior cranial fossa.

The accessory heads of flexor pollicis longus and flexor digitorum profundus: Incidence and morphology.

Kiloh-Nevin syndrome caused by compressive neuropathy of the anterior interosseous nerve in the forearm is believed to occur because of its compression by the accessory head of flexor pollicis longus (FPLah). Gantzer described two accessory muscles, the more frequent is the FPLah and the less frequently observed is the flexor digitorum profundus accessory head (FDPah). Many studies have reported the prevalence, origin, insertion, nerve supply, and relations of these accessory muscles, most of them focusing on the FPLah. This study was designed to investigate the prevalence, morphology, relation to median and anterior interosseous nerve, and also the coexistence of both the accessory heads. A total of 126 upper limbs of the embalmed cadavers were examined in this study. Fifty-eight limbs (46.03%) showed the presence of the FPLah and 18 limbs (14.28%) had the FDPah. The most common origin of both the accessory muscle bellies was from the under surface of the flexor digitorum superficialis. The FPLah inserted into the FPL muscle at varying levels with 80% inserting into the proximal third of FPL, whereas the FDPah in all cases ended near the level of the wrist joining with one or more tendons of the FDP. Clinical implication of the variation is discussed.

A study of anatomical variability of the omohyoid muscle and its clinical relevance.

OBJECTIVE: The omohyoid muscle is a long, thin muscle consisting of superior and inferior bellies and an intermediate tendon, which runs obliquely in the lateral cervical region. The omohyoid is important in neck dissections because it is the surgical landmark for level III and IV lymph node metastases. METHODS: In the present study, the anterior and posterior triangle of the neck was dissected in 35 male cadavers and observed for variations in the omohyoid bilaterally. Observations were focused on variations in number, attachments, and position of omohyoid. RESULTS: Among the 35 cadavers studied, double omohyoid was present in one cadaver, inferior belly originated from the clavicle in three cadavers, superior belly merged with the sternohyoid in two cadavers, and the omohyoid received additional slips from the sternum in one cadaver. Standard attachment and position of the omohyoid was observed in the remaining cadavers. CONCLUSION: Variations of this muscle are important because of its close relation to the large vessels and brachial plexus. Because of the direct adhesion of the intermediate tendon to the anterior wall of the internal jugular vein and its connection with it through a thin lamina of the pretracheal layer of the cervical fascia, the contraction of the omohyoid muscle has a direct effect on the lumen of this vessel.

An anomalous left external jugular vein draining into right subclavian vein.

Knowledge of the varying drainage patterns of superficial veins of head & neck, in particular, jugular veins are not only important for anatomists but also for the surgeons operating at this level and to clinicians in general. The variations are important also for interventional radiologists, who perform trans-jugular procedures, such as port implantations and trans-jugular intra-hepatic porto-systemic shunts or selective venous samplings. Results of recent studies report that the superficial veins, especially the external jugular vein, have been increasingly utilized for cannulation to conduct diagnostic and therapeutic procedures. We report a very unusual left-sided presentation of external jugular vein in an embalmed male cadaver. Embryological evaluations of the anomaly was done & compared with available literature, which showed that the observed variation is rare (Fig. 1, Ref. 12).

The palmaris longus muscle: its anatomic variations and functional morphology.

The functional morphology and evolution of the superficial forearm flexor, the palmaris longus, have long fascinated kinesiologists, physical anthropologists and anatomists alike. The anomalies, agenesis, variations and polymorphic presentation of the muscle, coupled with its biomechanical role in the performance of flexion and supination through distal articulations in the upper limb, have formed the base for many studies found in medical literature. We present data from published sources, along with our observations on the kinetics of palmaris longus, drawn from a series of dissections done on 30 cadavers. Complete agenesis was seen in four limbs. Reversal in the muscle-tendon orientation was seen in two limbs and duplication in one limb. The functional dynamics of the muscle and the clinical implication of its modifications in humans are discussed. We believe that every surgeon must be aware of the variations, since this, otherwise unimportant muscle, provides a very useful graft in tendon surgery.

A case report on accessory brachialis muscle.

Supernumerary heads or slips of brachialis (anticus) muscle is one among the most striking variations, described and encountered in the dissection routine. Very few studies are quoted in the list of its anomalies. We present a unique occurrence of an accessory brachialis muscle (acBr) that formed a fibro-muscular tunnel after blending with the medial intermuscular septum in the lower part of the arm. This tunnel contained the median nerve, the brachial artery and few additional twigs that innervated the neighboring muscles. Because of its intimate topographical relation with the neurovascular bundle, there is no doubt about its role, in the etiogenesis of various compression syndromes. Also, the brachial flexors received innervation from the median nerve, due to the absence of the musculo-cutaneous nerve. We discuss in this report the possible embryogenesis and the clinical application of this variation that can aid the physicians in their approach and required treatment.

Morphometric study of the semitendinosus muscle and its neurovascular pedicles in South Indian cadavers.

The purpose of this study was to determine the length of the semitendinosus muscle belly and its tendon in South Indian population and to study the topography and diameter of its neurovascular pedicles. The study included 46 formalin fixed human cadaveric lower limbs. The length of the semitendinosus muscle belly and its tendon were measured. The neurovascular pedicles of the semitendinosus muscle were identified and counted. The diameter of the neurovascular pedicle was measured just before its entrance into the semitendinosus muscle. The topographical distance of the neurovascular pedicles from the origin of the semitendinosus muscle were determined. The mean length of the semitendinosus muscle belly was 332.3±36.1 mm and its tendon measured 154.8±31.9 mm. The mean diameter of the vascular pedicle was measuring 11.4±9.1 mm, just before its entrance into the semitendinosus muscle. The neurovascular pedicles, of the semitendinosus muscle were ranging between 1 and 7. The distance of the entrance of neurovascular pedicle to the semitendinosus muscle from its origin was ranging between 46 and 272 mm. It was observed that the neurovascular pedicles were highest (31%) at the range of 151-200 mm away from the ischial tuberosity. The morphometric data obtained in the present study is enlightening to the orthopedic and plastic surgeons. The topographical knowledge of the neurovascular pedicles has its implications during the harvesting of the grafts and pedicle flaps. The diameter of vessels in the pedicles is enlightening because of new method of anterior cruciate ligament reconstruction.

Duplicated omohyoid muscle and its clinical significance.

The omohyoid muscle is one of the infrahyoid muscles with superior and inferior bellies. Variations of this muscle are clinically important because of its relation to the internal jugular vein as well as its significance in radical neck dissection. A duplicated omohyoid was observed during routine cadaver dissection, which is attached along with the usual inferior belly of the omohyoid into the transverse scapular ligament. Knowledge of anomalies of this muscle is important to minimize the complications during the surgical procedures of cervical region.

Anomalous channels draining the internal iliac veins: embryological and clinical significance.

During a routine cadaver dissection, we have encountered an anomalous formation of inferior vena cava and abnormal channels communicating the two internal iliac veins with the inferior vena cava in a 67 year old male cadaver. The said channels which had a caliber of 5 mm on the left side and 15 mm on the right arose at a distance of 26 mm on the left and 35 mm on the right from the internal iliac vein termination. Both the said channels moved medially and joined one another and formed a common stem (Cs) which finally terminated at the junction of the termination of right iliac vein into the inferior vena cava. The lumen of the terminal part had a diameter of 18 mm and it was 20 mm in length. Anomalies of the inferior vena cava and renal veins occur infrequently but if unidentified can lead to significant morbidity during surgical exploration. An understanding of the embryologic development of the vena cava and its tributaries is necessary to understand the genesis of these sometimes complex anomalies and their accompanying anatomic variants.