Morphological and Morphometric Relations of Infraorbital Foramen in North Indian Population

Introduction The evidence regarding the anatomy of the infraorbital foramen in the Indian population is limited. It mainly focuses on its shape, size, and incidence in the Indian population. The current study aimed to evaluate morphometric parameters of infraorbital foramen that can help clinicians during surgery and procedures around it. Methods We evaluated 90 dry adult human hemi-skulls. The morphological parameters studied included the assessment of the shape of the infraorbital foramen, its horizontal and vertical diameters, and its relation to the teeth of the upper jaw. In addition, we measured the distance of the infraorbital foramen from the anterior nasal spine, nasion, infraorbital margin, and the lower extent of the alveolar margin. The length of the infraorbital canal till the inferior orbital fissure and the infraorbital groove and the infraorbital canal orientation angles in different planes were also measured. The measurement values were compared between the right and left side hemi-skulls. Results The oval-shaped infraorbital foramen was most commonly noticed. The mean vertical and transverse diameters were 3.8 mm and 2.6 mm, respectively, on the right side. The left side's mean vertical and transverse diameters were 3.9 mm and 2.5 mm, respectively. The most common location of infraorbital foramen was in line with the maxillary second premolar tooth. The distances of infraorbital foramen from the alveolar margin were 29.6 mm and 29 mm on the right and left sides, respectively. The distances of the infraorbital foramen from the anterior nasal spine were 34.3 mm and 34.2 mm on the right and left sides, respectively. The distances of infraorbital foramen from the nasion were 42.3 mm and 42.2 mm on the right and left sides, respectively. The distances of infraorbital foramen from the inferior orbital margin were 5.8 mm and 6.2 mm on the right and left sides, respectively. The distances between the inferior orbital margin and infraorbital groove were 12.7 mm and 12.7 mm on the right and left sides, respectively. The distances between the inferior orbital margin and inferior orbital fissure were 27.5 mm and 27.1 mm on the right and left sides, respectively. The orientation angles of infraorbital foramen were 48.31° in the horizontal plane, 34.07° in the Frankfurt plane, and 14.4° in the parasagittal plane. Conclusion Our findings suggest that the location of the infraorbital foramen is difficult to standardize, considering the wide interindividual variations in the foramen relations. Further research should be performed to investigate the parameters related to the distance and orientation of the infraorbital foramen in relation to nearby bony landmarks that are least affected by individual variations in skull morphology.

Variations of Median Nerve Formation in North Indian Population

Introduction: The median nerve is usually formed by two roots contributed from the medial and lateral cords of the brachial plexus. Morphological variations of the median nerve can have clinical implications from the anesthetic and surgical points of view. In this cadaveric observation study, we report the variations of median nerve formation in the North Indian population.

Methods: We observed the formation of the median nerve in 40 human cadaveric upper limb specimens. The specimens belonged to 20 right and 20 left upper limbs. Variations in the formation of the median nerve were noted.

Results: Of the 40 dissected specimens, six (15%) had triple roots including a supernumerary root contributing to the medial nerve formation. The supernumerary root was a branch of the lateral cord in five cases, and it had an additional contribution from the medial cord in one case. The median nerve formation and continuation were located anterior or laterally in 39 specimens (97.5%) and medial in one (2.5%) in relation to the axillary artery.

Conclusion: We observed supernumerary roots of varying morphology contributing to the median nerve formation. These variations should be considered during the administration of regional anesthesia and during the management of brachial plexus injuries. Further large multi-region studies will help in a better understanding of these variations.

Radiographic Evaluation of Mastoid Parameters for Sexual Differentiation in North Indian Population

Introduction: Morphometric differences of several bones form the basis of sexual differentiation. The mastoid triangle has been widely used as a predictor of sexual differentiation. However, the radiographic measurements of the mastoid triangle, which form the clinical alternative of this parameter, have not been studied in the North Indian population. Therefore, we analyzed skull radiographs of live subjects to investigate the effectiveness of the radiographic mastoid triangle in sex determination.

Methods: One hundred skull lateral radiographs (55 male and 45 female) from the digital archives of a tertiary care teaching institute in Northern India were retrospectively analyzed. The following parameters: porion-mastoidale length, mastoidale-asterion length, asterion-porion length, and area of the mastoid triangle were measured. Gender-based differences for these parameters were then calculated for any statistical significance. Further, the low value of Wilks’ lambda, high values of Eigenvalues, and percentage of correct prediction accuracy denoted higher predictive value. Finally, discriminant function analysis was used to predict the relative validity of each measured parameter.

Result: All measured parameters were significantly higher in the male group. The porion-mastoidale length was 32.21±2.15 mm in males and 31.66±3.21 mm in females. The mastoidale-asterion length was 50.00±9.75 mm in males and 49.84±6.97 in females. The asterion-porion length was 44.11±6.82 mm in males and 39.72±5.77 mm in females. The area of the mastoid triangle was 690.74±123.35 mm² in males and 570.57±130.0 mm² in females. The area of the mastoid triangle has the highest relative validity (78%).

Conclusion: Considerable ethnic and racial differences have been observed in the radiographic morphology of the mastoid. The radiographic dimensions of the mastoid are potential predictors of sexual dimorphism. With the use of discriminant function analysis, the current study predicts the effectiveness of the area of the mastoid triangle as a reliable parameter for sexual differentiation in the Northern Indian population.

Morphometric Study of the Mastoid Triangle for Sexual Dimorphism of Dry Skulls in the North Indian Population

The mastoid process is a conical projection from the undersurface of the temporal bone. Examination of skeletal remains by anthropologists requires sex determination. The present study proposes to determine sex from morphometry of the mastoid process. The study was conducted on 300 dried skulls with the help of a digital vernier caliper. Discriminant functional analysis was performed. The parameters measured were the mastoid triangle, which is formed by specific points the porion, mastoidale, and asterion, and the linear distances between them. All parameters were higher in male skulls with a high level of significance. The area of the mastoid triangle proved to be the best parameter for sex discrimination.

CT Based Characterization of Volar Surface of Distal Radius: Can an Ideal Volar Plate for Fixation of Distal Radial Fractures be Designed?

Background: Literature has limited evidence concerning the morphology of volar surface of distal radius. A mismatch between the plate-contour and contour of the actual volar bony surface can result in malreduction. The purpose of this study is to analyze the normal curvature morphology of volar surface of distal radius and related parameters that can help in designing of the volar plates for fixation of distal radial fractures. Methods: We retrospectively analyzed CT scans of uninjured healthy distal radii performed during a one year period (2018-2019). The mediolateral extent of the pronator quadratus line, the mediolateral curve of the pronator quadratus line, the mediolateral surface angle between intermediate column and radial column of distal radius, the curvatures and locations of their vertices for radial and intermediate columns were measured. Results: A total of 84 CT-based studies were analyzed. The mediolateral extent of the pronator quadratus line, the mediolateral curve of the pronator quadratus line, and the mediolateral surface angle between intermediate column and radial column of the distal radius were 24.27 mm, 144.8 degrees and 163.1 degrees, respectively. The mean volar curvatures of the radial and intermediate columns were 156.5 and 151.4 degrees, respectively and distances of their vertices from the pronator-quadratus line were 10.96 mm and 14.13 mm, respectively. Conclusions: Considerable variations occur in curvature morphology of distal radial volar surface. A best fit rather than an anatomical fit can be considered during implant selection owing to these variations. Besides volar curvature of radial and ulnar columns, location of their vertices, mediolateral angulation and surface curvature between these columns at the level of watershed line should also be considered in plate selection. A combination of a few serial increments of the described parameters in the designs of volar fixation plates would be helpful for surgeons in the best implant selection.

Morphometric variations of the lateral surface of calcaneus: Can standard plate sizes fit all?

PURPOSE

Displaced intraarticular fractures of the calcaneum often require plate fixation. The complex fractures are usually fixed with standard lateral plates and are approached via the extensile lateral approach which is fraught with the risk of wound complications. Oversized calcaneal plates produce tension on the wound closure site and can, thus result in wound healing problems. The current study analyses the morphometry of the lateral surface of the calcaneus for the ideal configuration of the calcaneal plates for Indian patients using a CT based analysis of intact calcanei.

METHODS

Fifty CT based studies of normal calcanei were retrospectively analyzed using Horos® software version 3.3.5. The cross-section of the lateral third of calcaneum was assessed for the morphometric measurements relevant to the dimensions of the standard plating devices for calcaneum. We measured the overall plating length of calcaneum, the vertical heights at the anterior process and calcaneal tuberosity, the height of the posterior facet, the lengths of the anterior process, and the posterior facet. The inclination angles of the posterior facet, cuboid facet were also measured. The findings were compared between male and female cases.

RESULTS

The mean plating length of the calcaneus was 60.06 ± 4.05 mm. The mean vertical height of the anterior process and the calcaneal tuberosity were 24.3 ± 2.71 mm and 39.48 ± 4.73, respectively. The length of the anterior process and the posterior facet were 21.36 ± 1.72 and 25.02 ± 4.17, respectively. The mean Gissane angle and the angle of inclination of posterior facet in relation to the plating length were 118.04 ± 5.99° and 47.3 ± 5.20°. The mean anterior slant angle of the cuboid facet was 96.64 ± 4.39°. Significant differences were observed in the measurements among male and female groups except for the angular parameters.

CONCLUSION

The current analysis suggests the individual morphometric variations of the lateral plating surface of the calcaneus. Although female calcanei have smaller dimensions compared to male calcanei, the angular parameters are comparable among the two groups. Considering the wide variations in the majority of the morphometric parameters, it is difficult to standardize the plate dimensions. However, a few serial increments in the plate dimensions can help in providing the best fit rather than an ideal fit. Also, the plates should be available with multiple inclination angles of the facet limbs according to the local population variations.

Reliability of relation between greater trochanter and center of rotation of femoral head in Indian population

PURPOSE

Accurate limb length restoration forms an important aspect of reconstructive surgeries around the hip joint. Among the various intraoperative methods for accurate limb length restoration, the relation between the greater trochanter and the center of the femoral head has been conventionally used owing to its simplicity and replicability. The current study aims to study the normal relation between the greater trochanter and the center of rotation of the femoral head, its population-based variation and its gender-based and contralateral differences in the Indian population.

METHODS

Standard anteroposterior radiographs of normal hip joints with the proximal femur, performed over a one year period were studied. A software-based analysis was conducted to measure the difference between the levels of the greater trochanteric tip and the center of the femoral head along the longitudinal axis of the femur. The measurements among the male and female cases and the contralateral sides were compared.

RESULTS

The greater trochanteric tip lies at a higher level than the center of rotation of the femoral head by a mean difference of 9.20 ± 5.30 mm. No significant differences were observed among male and female groups and between the contralateral hip joints. Intraobserver and Interobserver reliability were high.

CONCLUSIONS

The tip of the greater trochanter and the center of the femoral head do not lie at the same level. This differential relation should be considered during the reconstructive surgeries around the hip joint to prevent an inadvertent limb length discrepancy. Considering the wide interindividual variations, this difference cannot be generalized for all the patients and restoring it to the contralateral normal hip would be more appropriate.

Risk of bony violation with standard triple screw configurations for fixation of femoral neck fractures: A preliminary computed tomography based analysis

PURPOSE

The reduction and fixation of femoral neck fractures is mainly an indirect one with intraoperative fluoroscopy being trusted for the safe containment of screws within the bony limits of the femoral neck. Radiologically undetected bony perforations may have an impact on the fracture stability and radiological outcomes that have not been studied previously. The purpose of this computed tomography (CT) based study is to analyze the safety of containment of triple screw configurations using standard 6.5 mm diameter screws for fixation of femoral neck fractures in the Indian population using a software-based analysis.

METHODS

Data from consecutive CT scans with intact proximal femur performed over a six month period were retrospectively analyzed using iPlan® BrainLab AG, Feldkirchen, Germany. The safe containment of virtual screw trajectories placed in inverted triangular and non-inverted triangular configurations for a 6.5 mm diameter screw was analyzed in intact femoral necks.

RESULTS

A total of 72 cases were considered for the final assessment. For 6.5 mm screws, the proportion for safe containment (without bony violation) of triple screw inverted triangular configuration was 75% with additional safety corridor to 1 mm around the screw trajectories and 31.94% for non-inverted triangular configuration. All male cases and 28% of female cases allowed safe placement of three 6.5 mm screw trajectories in an inverted triangular pattern with a safety margin of 1 mm around the screw. Replacement of one of the two superior 6.5 mm diameter screw trajectories with a 4.5 mm diameter trajectory resulted in 100% safe containment in female cases.

CONCLUSION

Inverted triangular configuration is a relatively safer configuration compared to the non-inverted triangular configuration. Standard triple 6.5 mm screws for fixation of femoral neck fractures carry a risk of bony violation, especially in females. A preoperative radiographic assessment to screen the cases with narrow vertical and anteroposterior extents of the femoral neck can help in reducing the risk of fluoroscopically undetected violation of the bony margins. Replacement of one of the two superior screws with a 4.5 mm diameter screw can be helpful in such cases.

Defining the "mediolateral widening of tibial plateau" as a guide for reduction in tibial plateau fractures: An Indian perspective

PURPOSE

The primary aim in fixation of the tibial plateau fractures is the restoration of normal anatomy. Evaluation of the widening of the tibial plateau, which has been linked with adverse long term outcomes, still needs precise markers for quantification. The purpose of this study is to analyze the normal limits of tibial plateau widening in the Indian population in relation to the distal femur in a standardized manner to provide important radiological parameters for the same.

METHODS

We retrospectively analyzed electronically archived true AP radiographs of uninjured normal knee joints during one year between 2018 and 2019. We measured the mediolateral width of the articular surface and extraarticular extent of the tibial plateau and compared them with the distal femoral articular and extra-articular extents. The measurements were compared between the male and female groups.

RESULTS

Tibial plateau articular width was found to be 4% wider in relation to the distal femoral articular surface. The medial articular rim of distal femur matches closely to the medial articular rim of the tibial plateau. The lateral articular rim of distal femur lies medial to the lateral articular rim of tibial plateau with a mean distance of 3.49 mm.

CONCLUSIONS

Owing to individual variations in bony extents around the knee, the differential extent of tibial plateau relative to distal femur would be a more reliable parameter than absolute measurements. Medially the articular extent of distal femur matches closely with the articular extent of tibial plateau while the lateral extra-articular extent of distal femur matches closely with the lateral tibial articular extent. Gender-based differences do not significantly affect these two parameters.

Malleolar tips as reference points for positioning of syndesmotic screw: A preliminary CT based analysis

PURPOSE

The risk of malpositioning of the syndesmotic screws is very high. A lack of standard radiological or physical references for accurate syndesmotic screw placement is a potential contributing factor in syndesmotic screw malpositioning. Malleolar tips are clinically as well as radiologically appreciable bony references. The purpose of this preliminary CT based study was to investigate the axial relations of the central syndesmotic axis with the malleolar tips.

METHODS

CT based studies of uninjured adult ankle joints with intact syndesmosis, conducted over a six months period were analysed. The axial differences between the coronal plane along the malleolar tips and that along the central syndesmotic axis in the axial plane were measured. Gender-based variations were also analyzed.

RESULTS

A total of 70 CT studies were analyzed, and the axial difference between the malleolar tips based coronal plane and that along the central syndesmotic axis was observed to be 3.70 ± 5.61°. The male and female measurements were comparable.

CONCLUSION

Being in a static relation to the syndesmosis independent of the foot position and the limb rotation, the malleolar tips can be reliably used as references for directing syndesmotic screw in the axial plane. A knowledge of this axial difference between malleolar tips and central syndesmotic axis can help surgeons in an accurate syndesmotic screw placement.

Fracture of first metacarpal head: A rare case presentation and review of literature

Fractures around the head and neck region of first metacarpal are unusual and have not been reported in literature. We report a case of fracture of head of first metacarpal with intact articular surface, treated with open reduction and internal fixation, with a follow up period of six months. Surgical procedure, intraoperative difficulties in obtaining reduction and steps to overcome them have been described. Satisfactory functional outcomes can be achieved using stable internal fixation with minimal hardware and early mobilization in first metacarpal head fractures.

Morphometric analysis of the anterior column of the acetabulum and safety of intramedullary screw fixation for its fractures in Indian population: a preliminary report

INTRODUCTION

Morphometric variations of the anterior column of the acetabulum have been described in the literature for its complex structure, which can influence the safe containment of intramedullary screw for fixation of its fractures. The purpose of this CT-based study is to present a preliminary report on the morphometric variations and safety of intramedullary screw fixation of the anterior column of the acetabulum in the Indian population.

METHODS

CT-based data from 102 uninjured pelves were retrospectively analyzed in iPlanⓇ BrainLab AG, Feldkirchen, Germany. Narrowest zones around acetabulum and superior pubic ramus were measured. We calculated the axis of the anterior column of the acetabulum by joining the centres of these narrowest zones. Standard screws trajectories were directed along this axis. Screw length up to the first cortical perforation, the distance of the exit point from the pubic symphysis, and the length of the anterior column up to the pubic tubercle were measured.

RESULTS

The osseous corridor of the anterior column of acetabulum had variable cross-section along its length with two constriction zones, first in the acetabular region and second in the superior pubic ramus. Only 54% of our cases allowed safe applicability of 6.5-mm-diameter screw trajectories with safety margin of 2 mm on either side of the screw. Significant morphometric and screw applicability-related differences were observed among male and female cases with males having a wider osseous corridor in general. Elimination of safety margin results in a significant increase in the screw applicability.

CONCLUSION

The osseous corridor of the anterior column varies in its dimensions from individual to individual. Standard screws of 6.5-mm and 7.3-mm diameters may not be safe for intramedullary screw fixation in every patient and carry a risk of cortical violation when a 2 mm of width around the screw is considered as a safety margin. However, with a precise screw placement within the extents of the cortices of the anterior column, 6.5-mm screws can be applied in most of the female cases and 7.3-mm screws can be applied in most of the male cases for anterior column fixation.

Ectopic third molar tooth on the infratemporal surface of maxilla

Ectopic eruption of a tooth within the dentate region of the jaws is often noticed in clinical practice and is well documented in the literature but the ectopic eruption into the non dentate region is rare. Diverse anatomical locations such as nasal cavity, nasal septum, mandibular condyle, coronoid process, the palate and the maxillary sinus can infrequently be non dentate sites of ectopic eruptions of teeth. While conducting an anthropometric study on 100 skulls incidental and interesting case of ectopic maxillary third molar tooth was found. The tooth was partially erupted with the unerupted part lying impacted in the posterior wall of maxilla. The case is reported and discussed for its significant clinical implications.

Vagal schwannoma in parapharyngeal space -anatomical perspective

A rare case of Schwannoma of Vagus nerve in Parapharyngeal Space was admitted in Otolaryngology department of GSVM Medical College, Kanpur, Uttar Pradesh, India. Schwannoma is a rare tumor in the Parapharyngeal Space.  The   patient was a 32 yr old male with  chief complaints of difficulty in swallowing and swelling in the neck since last 4 years. On examination there was a firm swelling on right side of neck and uvula was deviated towards Left Side. On CT & MRI examination a heterogenous mass was seen in Parapharyngeal space. The case was diagnosed as a case of vagal schwannoma in parapharyngeal space. The tumor was surgically excised. Histopathological Examination revealed the Tumor as Schwannoma. Asian Journal of Medical Sciences Vol.7(2) 2015 100-103

Sex determination using mastoid process

Objective: Osteometric studies using individual bones have been a topic of interest among researchers. Such researches are a tool for conducting studies related to evolution, demographic profiles and forensic sciences. Skull is important in this regard as it resists adverse environmental conditions over time. The mastoid process can thus be used as a marker of sex as well as ancestry of individuals and populations. The aim of this study was to evaluate the use of mastoid process as a tool for sex determination in unidentified skeleton. Materials and Methods: 70 (44 male and 26 female) complete undamaged skulls of known sex were used for the study. Mastoid length was recorded on the right and left mastoid process in each skull. Measurements were made with a digital vernier caliper. Results: Statistics revealed high significance (p<0.0001) for the mastoid length for sex determination. Conclusion: Reports on the use of mastoid process as a tool for sex estimation in unidentified human skeleton have been reported in different populations. The present study supports this finding among the Indian population.DOI: http://dx.doi.org/10.3126/ajms.v6i6.12406 Asian Journal of Medical Sciences Vol.6(6) 2015 93-95

Wegener's granulomatosis: an unusual cause of upper airway obstruction

A 10-year-old child with a 2-month history of tracheitis presented with acute stridor, for which he required tracheostomy. Granulation tissue was found in the subglottic region and he was treated with antibiotics and corticosteroids. A week after successful decannulation of his tracheostomy, his stridor recurred and, on endoscopy under general anaesthesia, circumferential granulomas extending into both main bronchi were found. A diagnosis of Wegener's granulomatosis was made and confirmed on histology.