Bony landmarks, distances and their correlations to each other, which can be used during periacetabular osteotomy: a CT study performed on dysplastic hips

As a surgical technique for hip dysplasia, Bernese periacetabular osteotomy (PAO) still poses technical difficulties and unclear surgical steps like the depth of the first ‘ischial’ cut, the start of the iliac cut and the width of the retroacetabular cut to prevent either iatrogenic joint entrance or posterior column fracture. Twenty-seven dysplastic hips (CE < 25°) were randomly matched with nondysplastic hips (n: 27, CE > 25°). 3D CT sections of the hips were evaluated and the width of the ischium, the distance from the infra-acetabular groove to the ischial spine, from the anterior superior iliac spine (ASIS) to the joint or sciatic notch or the sciatic spine, from the most medial point at the acetabulum to the posterior column, ischial spine or sciatic notch were measured for each group and correlated. The distances (mm) from the infra-acetabular groove to the ischial spine (42 ± 4, 44 ± 4, P: 0.03), the anterior superior iliac spine to the joint (52 ± 6, 60 ± 3, P: 0.03), the most medial point at the acetabulum to the posterior column (34 ± 2, 36 ± 2, P: 0.005) were shorter in the dysplastic group. The distance from the ASIS to the sciatic notch was correlated with the distance from the infra-acetabular groove to the ischial spine, from the ASIS to the joint and the most medial point at the acetabulum to the posterior column. The distance from the ASIS to the sciatic notch can be used intraoperatively to guess the X-ray guided or blindly osteotomized stages to predict the width or depth of the osteotomy to prevent intraarticular extension or posterior column fracture.

STUDY OF GREATER SCIATIC NOTCH FOR DETERMINATION OF SEX OF HIP BONE BY METRIC METHOD

Background: The distinctive morphology of human skeleton and its clear sexual dimorphism make it of interests from anatomical, forensic, obstetrical, radiological and anthropological point of view. The hip bone is considered as an ideal bone for sex determination as it provides the highest accuracy levels. Many workers have studied various metric parameters for sexing of hip bone. Methods: The present study was done with an aim to find out the sex of hip bone using various parameters of greater sciatic notch. For this purpose, 100 dry hip bones were collected from the Department of Anatomy. Seven different parameters of the greater sciatic notch were used for the study: Maximum width, Maximum depth, Posterior segment, Index I, Index II, Total angle and Posterior angle. Results: All the parameters (especially posterior segment, posterior angle and index II) were found to be highly indicative of sex hip bone by t- test (p<0.005) except the depth. Conclusion: By the present study it was concluded that the width and depth of the greater sciatic notch were a less useful criteria for sexing purposes while the posterior angle was found to be the best parameter, which identified 75 % of left and 88 % of right male hip bones and 92 % of left and 100 % of right female bones. Length of the posterior segment and Index II also assigned sex to a high percentage of hip bones, specially to the female ones (95-97 %), these results suggests that the widening of the greater sciatic notch found in females has occurred mainly in its posterior part. Keywords: Hip, Bone, Index

The clinical outcomes after surgical treatment of mass lesions causing sciatica - a single-center retrospective study

Introduction/Objective Sciatica is a disabling pathology with variable etiologies. The most common pathologies arise from discogenic or non-discogenic causes. Mass lesions are a rare cause of extraspinal sciatica, which have been commonly overlooked, leading to unnecessary spinal surgeries, delay in diagnosis or inadequate treatment. There is no standard surgical approach and functional outcomes after surgical treatment of these lesions are not well-known. The aim of this study is to evaluate clinical outcomes after surgical treatment of mass lesions causing sciatica in different locations. Methods Data were obtained by a retrospective review from 2015-2020. The mean duration of symptoms at the time of surgery was 10.3 months (3-48 months). The mean age of patients at the time of surgery was 43.8 years (14-73 years). The mean follow-up was 19.5 months (4-50 months). In total, 14 cases had an extrapelvic localization distal to sciatic notch. The other three cases had lesions in the intrapelvic area, including left sciatic notch (1), right acetabulum (1), sacroiliac and lumbosacral region (1). None of the patients had palpable masses. Transgluteal, infragluteal, lateral, and posteromedial approach were used depending on location and size of the lesion. Results At the final follow-up, all patients recovered pain relief. The median musculoskeletal tumor society score was 90% (70-100). There was no recurrence at the latest follow-up. Conclusion Our study demonstrated that early detection by neurological examination and radiological work-up can avoid unnecessary surgeries, enable early surgical treatment of tumoral mass with satisfactory clinical outcomes. The surgical approach should be individualized according to location and size of the lesion.

A three-dimensional computed tomography study to determine the ideal method for fluoroscopically-guided bone marrow aspiration from the iliac crest

Bone marrow aspiration (BMA) through the iliac crest is potentially unsafe due to the vicinity of neurovascular structures in the greater sciatic notch. Our objective was to investigate the safety of a recently described BMA technique, specifically a trajectory from the posterior superior iliac spine (PSIS) to the anterior inferior iliac spine (AIIS). We conducted a chart review of 260 patients, analyzing three-dimensional reconstructed computed tomography images of the pelvis and sacrum to validate that this new approach offers a wide safety margin from the greater sciatic notch. Analysis of three-dimensional computed tomography scans demonstrated that the PSIS to AIIS trajectory never crossed the greater sciatic notch. The trajectory was noted to be at least one cm away from the greater sciatic notch in all measurements. The new trajectory entered the PSIS at 25.29 ± 4.34° (left side) and 24.93 ± 4.15° (right side) cephalad from the transverse plane, and 24.58 ± 4.99° (left side) and 24.56 ± 4.67° (right side) lateral from the mid-sagittal plane. The area of bone marrow encountered with the new approach was approximately 22.5 cm2. Utilizing the same CT scans, the trajectory from the traditional approach crossed the greater sciatic notch in all scans, highlighting the potential for violating the greater sciatic notch boundary and damaging important neurovascular structures. Statistically significant sex-related differences were identified in needle trajectory angles for both approaches. We conclude that based on this three-dimensional computed tomography study, a trajectory from the PSIS to the AIIS for BMA may offer a wide safety margin from the greater sciatic notch.