Can Lateral Offset Be Used as a Predictive Marker for Proximal Femur Disorders?

Purpose: When the lateral offset (LO) changes, the forces acting on the head and neck of the femur change. Increase or decrease in LO can cause instability and possible dislocation of the implant. In addition, when the offset is reduced, more force is needed to balance the pelvis by the abductor muscles, and the force that occurs along the hip joint increases and causes wear and tear. In this study we aimed to investigate whether there is a correlation between LO and proximal femur morphology, and according to the results we aimed to investigate whether the LO can be used as a predictive marker for the risk of femoral neck fractures, osteoarthritis or femoroacetabular impingement. Methods: Femur length, femur neck length, femoral neck-shaft angle (NSA), anteroposterior (a-p) and superoinferior (s-i) diameters of femoral head and neck, and LO were measured on 82 dry adult femora of unknown age and gender from Turkish population. Results: There was no statistically significant correlation between the LO and a-p and s-i diameters of femoral head or neck. However, there was found statistically significant correlation between LO and femoral NSA (p < 0.01), femoral neck length (p < 0.05) and femur length (p < 0.01). Conclusion: High LO values can be used as an indicator for neck fractures, a negative marker for OA, but LO does not appear to be used as an indicator for FAI.

Morphological characteristics of the posterior neck muscles and anatomical landmarks for botulinum toxin injections.

PURPOSE: Cervical dystonia is a common movement disorder for which botulinum toxin (BoNT) is the first choice treatment. Injecting the specific neck muscles can be challenging because of their thin morphology and deep locations. We, therefore, designed a study to investigate the locations of the posterior neck muscles to help the physician predict the locations of the targeted neck muscles and to protect the vertebral vessels from injury during deep injections. METHODS: The posterior neck region was divided into four quadrants by imaginary lines passing vertically and transversely through the spinous process of C2 vertebra (C2sp). The thicknesses and depth of the posterior neck muscles were measured in ten formaldehyde-fixed adult male cadavers. These muscles were located and a projection of them was drawn on the neck. Using the measurements, colored latex in place of BoNT was injected into them in one cadaver. The cadaver was dissected to investigate whether the muscles were colored. RESULTS: 2 cm above the C2sp, trapezius, splenius capitis (SPC) and semispinalis capitis (SSC) were colored at depths of 10.70 mm, 11.88 mm and 15.91 mm, respectively. 2 cm below the C2sp, the trapezius, SPC and SSC were colored at depths of 20.89 mm, 23.25 mm and 27.63 mm, respectively. The posterior neck muscles were had taken up their assigned colors when they were injected according to the results obtained in this study. The vertebral vessels were not colored. CONCLUSIONS: Although BoNT injection into the posterior neck muscles is challenging, we think that it can be practically and safely applied using the measurements obtained in this study.

The Anatomical Relationships of the Ocular Motor Nerves with an Emphasis on Surgical Anatomy of the Orbit.

The surgical procedures directed to the orbit are invariably reported to be one of the most challenging procedures of the neurosurgery and it is very important to take measures to protect the ocular nerves. Many researchers have tried to identify safe approaches or safe regions in the orbit but the suggestions and results vary among published studies. The ocular motor nerves are under risk of injury during various approaches to the orbit. Simple but careful attention to potential variations in the origin and anatomical course of the ocular nerves and their relationships to the orbit may help to define "safe zones" during various approaches, thus, help to enhance clinical outcomes. The objective of this review, therefore, is to discuss the surgical anatomy of the orbit with special emphasis on oculomotor, trochlear, and abducens nerves and further emphasize their relationships with a surgical point of view during various approaches directed to the orbit. Anat Rec, 302:568-574, 2019. © 2018 Wiley Periodicals, Inc.

Surgical anatomy of the superior gluteal nerve and landmarks for its localization during minimally invasive approaches to the hip.

The superior gluteal nerve (SGN) is vulnerable to damage during total hip arthroplasty and various pelvic surgeries. Recently introduced minimally invasive approaches to the hip show promise for less muscle trauma compared to conventional approaches. However, the risk of damaging the SGN has not been well documented for such alternative approaches. Therefore, we aimed to investigate the anatomic course of the SGN and to define anatomical landmarks that may be used by surgeons during minimally invasive approaches to the hip. Twenty-eight gluteal regions from 14 formalin-fixed cadavers were dissected and the course and the distances of the SGN and its branches to the tip of the greater trochanter (GT) were measured. The landmarks for standardizing the course of the SGN included the posterior inferior iliac spine (PIIS), GT, and a line (PIIS-GT) connecting these two points. The exit of the SGN was found to be at the medial one third of the PIIS-GT line and 5.4 cm from the GT. Two branching patterns were noted. The branches of the SGN were distributed lateral to the PIIS-GT line. On the basis of our study, the safe zone for the SGN was smaller than previously reported. Posterior, lateral, or anterolateral minimally invasive approaches to the hip should take into account the point of exit of the SGN and the area of distribution of its branches. A minimally invasive anterolateral approach may particularly compromise branches to the tensor fasciae latae muscle. Localization of the SGN and its branches using the anatomic landmarks defined in this study may decrease surgical morbidity.

Motor nerve lengths of twenty-seven muscles in upper extremity.

The purpose of this study is to determine the lengths of motor nerves in the upper extremity. Motor nerves of 27 muscles in 10 cadavers (16 extremities) were dissected from their roots at the level of intervertebral foramen to the entry point of the nerves to the corresponding muscles. Distance between acromion and the lateral epicondyle of the humerus was also measured in all cadavers. Nerve length of the coracobrachialis muscle was the shortest (18.26 ± 1.64 cm), while the longest was the nerve of the extensor indicis (59.51 ± 4.80 cm). The biceps brachii, the extensor digitorum communis, and the brachialis muscles showed highest coefficient of variation that makes these nerve lengths of muscles inconsistent about their lengths. This study also offers quotients using division of the lengths of each nerve to acromion-the lateral epicondyle distance. Knowledge of the nerve lengths in the upper extremity may provide a better understanding the reinnervation sequence and the recovery time in the multilevel injuries such as brachial plexus lesions. Quotients may be used to estimate average lengths of nerves of upper extremity in infants and children. Moreover, reliability of the biceps brachii as a determinant factor for surgery in obstetrical brachial plexus lesions should be reconsidered due to its highest variation coefficient.

Temporal branch of the facial nerve and its relationship to fascial layers.

OBJECTIVES: To eliminate the inconsistency in the nomenclature, to anatomically and definitively describe the topographic relationship of the temporal branch of the facial nerve to the fascial layers and the fat pads, and to create an effective algorithm to define the safest approaches and planes for surgical procedures in this area. METHODS: The study was performed using 18 hemifacial cadaveric specimens. In 12 hemifacial specimens, the facial halves were coronally sectioned and dissected. In 6 hemifacial specimens, planar dissection was performed layer by layer. RESULTS: The temporal branch of the facial nerve that traversed inside the deep layers of the temporoparietal fascia and the superficial musculoaponeurotic system coursed along the zygomatic arch as 1 (14.3%), 2 (57.1%), 3 (14.3%), and 4 (14.3%) twigs in the specimens. The temporoparietal fascia had no attachment to the zygomatic arch and continued caudally as the superficial musculoaponeurotic system. Adhesions were between the temporoparietal fascia and the superficial layer of the deep temporal fascia around the zygomatic arch. In most specimens, the superficial layer of the deep temporal fascia continued as the parotideomasseterica fascia, and a deep layer abutted the posterosuperior edge of the zygomatic arch. CONCLUSION: An easy and safe surgical approach in this area is to elevate the superficial layer deep to the intermediate fat pad directly on the deep layer of the deep temporal fascia descending to the periosteum along the zygomatic arch.

Window anatomy for neurosurgical approaches. Laboratory investigation.

OBJECT: Knowledge of the cranium projections of the gyral structures is essential to reduce the surgical complications and to perform minimally invasive interventions in daily neurosurgical practice. Thus, in this study the authors aimed to provide detailed information on cranial projections of the eloquent cortical areas. METHODS: Ten formalin-fixed adult human skulls were obtained. Using sutures and craniometrical points, the crania were divided into 8 windows: superior frontal, inferior frontal, superior parietal, inferior parietal, sphenoidal, temporal, superior occipital, and inferior occipital. The projections of the precentral gyrus, postcentral gyrus, inferior frontal gyrus, superior temporal gyrus, transverse temporal gyri, Heschl gyrus, genu and splenium of the corpus callosum, supramarginal gyrus, angular gyrus, calcarine sulcus, and sylvian fissure to cranial vault were evaluated. RESULTS: Three-fourths of the precentral gyrus and postcentral gyrus were in the superior parietal window. The inferior frontal gyrus extended to the inferior parietal window in 80%. The 3 important parts of this gyrus were located below the superior temporal line in all hemispheres. The orbital and triangular parts were in the inferior frontal window, and the opercular part was in the inferior parietal window. The superior temporal gyrus was usually located in the inferior parietal and temporal windows, whereas the supramarginal gyrus and angular gyrus were usually located in the superior and inferior parietal windows. The farthest anterior point of the Heschl gyrus was usually located in the inferior parietal window. The mean positions of arachnoid granulations were measured as 3.9 +/- 0.39 cm anterior and 7.3 +/- 0.51 cm posterior to the bregma. CONCLUSIONS: Given that recognition of the gyral patterns underlying the craniotomies is not always easy, awareness of the coordinates and projections of certain gyri according to the craniometric points may considerably contribute to surgical interventions.

The precise localization of distal motor branches of the tibial nerve in the deep posterior compartment of the leg.

The tibial nerve has been reported to be often iatrogenically injured during fibular graft harvest, high tibial osteotomy and fascial release procedures. Despite this complication, there are limited data available in the literature concerning the surgical anatomy of tibial nerve branches in the deep posterior compartment of the leg. The aim of the present study was to quantitative and localize the motor nerve points for the flexor hallucis longus (FHL), tibialis posterior (TP) and flexor digitorum longus muscles (FDL) in relation to a regional bony landmark. The range for the number of branches of the tibial nerve and the terminal motor points of each muscle were identified and measurements were made with a digital caliper from these points to the apex of the head of fibula. Three particular types in the branching of tibial nerve were determined. In 55.6% of the cases there were separate branches to each of the muscles in the deep posterior compartment of the leg (Type I). In 30.6% of the cases there were two main branches of the tibial nerve that provided motor branches (Type II). Finally, the tibial nerve had one main branch, which gave rise to separate motor branches to each of the muscles in 13.8% (Type III). In 61.1% of the cases the FHL was innervated by proximal and distal branches of the tibial nerve. In 38.9% of the cases, it was innervated only by one proximal branch. In all of our cases, the TP was innervated by both proximal and distal branches and the FDL innervated only distally. This provided a detailed anatomical description of the tibial nerve in the deep posterior compartment of the leg. Knowledge of the variable peripheral course of the tibial nerve, as well as the detailed anatomy of its motor branches may decrease iatrogenic injuries and motor loss of the foot during surgical procedures.

High-located aberrant innominate artery: an unusual cause of serious hemorrhage of percutaneous tracheotomy.

An aberrant innominate artery located high was observed during a cadaveric neck dissection. To our knowledge, an innominate artery crossing the 4th and 5th tracheal rings has rarely been reported in available literature. Knowledge of this anomaly is important for those who are involved with percutaneous procedures in the neck to avoid major complications.