The epiphyseal ring project

The epiphyseal ring is one of the important and unique structures in the human body. Despite its major role in spinal stability (anchoring the intervertebral disc via the annulus fibrosus to the vertebral body), this structure shrinks in humans into a narrow marginal bony belt. The significance of this process and its association with the evolvement of erect posture, as well as its effect on the stability and flexibility of the spinal motion segments, is obscure. The clinical outcome of this process and its effects has never been studied.

The aims of the current study are:
a- to explore the structure and function of the epiphyseal ring in mankind, and to better understand its relations to other components of the vertebrae and the intervertebral disc.
b- to examine the evolutionary processes that led to the development of a distinctive epiphyseal ring and end-plate in humans.
c- to correlate between the morphological features of the epiphyseal ring and various spinal diseases.

The osteological study will be carried out on the complete spine (dry vertebrae) of 120 humans, 15 chimpanzees, 15 gorillas and 15 gibbons. The study of the microstructure of the epiphyseal ring and associated end-plate will be carried out on samples taken from human and non-human cadavers. The radiological study will be carried out on a data base of 120 young patients who were referred for a CT of the lumbar spine. The metric analysis will be carried out with a MicroScribe 3-D apparatus and dedicated image processing software. CT studies analysis will be performed on a radiological workstation, using volume rendering and quantitative analysis methods.

We hope that this multidisciplinary research (involving anthropologists, anatomists, physiotherapists, radiologists and orthopedic surgeons) of the long forgotten epiphyseal ring will shed light not only on the processes via which the spine adapted itself to bipedal locomotion, but also on the etiology and pathophysiology of many spinal diseases.

The ligamentum flavum and Lumbar spinal stenosis
The ligamentum flavum (LF) is a yellow elastic ligament extending from the second cervical vertebra to the first sacral one. It connects two adjacent lamina, and is considered the important element of the posterior wall of the neural canal.
Lumbar spinal stenosis (LSS) is the most common spinal disorder in elderly patients, which may lead to low back pain, leg pain and paresis.
LSS is mainly acquired and congenital stenosis is rare. Acquired stenosis is caused mostly by degenerative changes in the inter-vertebral (IV) disc, facet joints, lamina and ligament flavum, or any combination of these elements.
The purposes of this study are: to detect the relationship between morphometric measurements of the spinal canal and LSS, to perform histological study of LF specimens of LSS. We will also determine any correlation between demographic characteristics (origin, age, gender, weight, height, pregnancies) and development of LSS patients.

Computer Aided Quantitative Examination of Computed Tomography Imaging of the Lumbar Spine for Diagnosis of Low Back Pain

In this research we wish to develop and validate a computer aided radiological toolbox which will enable clinicians to gain quantitative and qualitative insight to the general status of the lumbar spine in individuals with LBP, to wit: distorted configuration (e.g., severe lordois), pathologies (e.g., spondylolisthesis), degenerative processes (e.g., osteophytes, disk height), congenital defects (e.g., scoliosis, spodylolysis), etc.

The Etiology and Pathophysiology of the Concave- Convex Wear Pattern in the Lower Dentition
The interproximal wear is the development of the flattened facets or polished, bright plan area at the points of contact between adjacent teeth. According to Begg, the amount of interproximal wear is correlated with the chewing force required by the food. Inter-proximal wear is the result of differential movement of teeth during mastication. The causes for inter-proximal attrition are mainly the lateral movement of the teeth combined with the mesial force vector. The unique wear pattern of concave- convex was suggested as a way to increases stability of the dental arch and to reduce anterior crowding. In general, it seems that the cause of this unique pattern of wear is a combination of several factors, which we could represent as a mechanical question.
The skeletal material will include 500 human skulls and mandibles and 100 skulls of non-human primates from the Hamman-Todd Osteologic Collection in Cleveland. Measurements of the dentition, jaw and muscles of mastication will be made. The mechanical factors and pathologies will be examined.

Sacroiliac Joint Bridging: Demographical and Anatomical Aspects

A descriptive study of the association between sacroiliac joint bridging (SIB) and age, gender, laterality and ethnic origin in a normal skeletal population. The effectiveness of x-rays in identifying SIB was also evaluated.
The major objectives were to characterize the phenomenon of SIB demographically and anatomically and to evaluate the validity of diagnosis based on roentgenograms.
Although SIB is an important diagnostic parameter in many spinal diseases, the type of association between them has never been established. Furthermore, the extent of SIB in humans and its relationship to demographic parameters await osteological research as X-rays studies hamper the results. 2845 skeleton pelvises were examined for SIB. Extent and laterality were recorded. Ten pelvises (5 with SIB and 5 without) were x-rayed and the roentgenograms given to radiologists for evaluation.
Sacroiliac bridging was present in 12.27% of all males, contrasted with only 1.83% of females (p<0.001). SIB was independent of ethnic origin (p=0.0535), but was age-dependent (r =0.985; P=0.0001). Bridging was present bilaterally in 38.6% of the individuals and in the superior region in 72.4%. Diffuse bridging (areas 1-6) was present in only 2.3% of the individuals. Radiological examination was insensitive to diagnosis of SIB. In conclusion, SIB is a common, but predominantly male phenomenon. Its occurrence is age dependent and ethnicity independent. Bridging occurs mainly on the superior aspect of the sacroiliac joint. The irregular shape and orientation of sacroiliac joints preclude definitely distinguishing normal versus bridged joints from roentgenograms. Our findings also negate the belief that bridging/fusion of the sacroiliac joint represents the most severe form of osteoarthritis and mandate that they be separately recorded, and their significance determined.

The sacrum as a key element in spinal alignment

“Nothing in biology makes sense except in the light of evolution” (Theodosius Dobzhansky, 1900-1975)

In the course of evolution, the sacrum underwent only minimal change in its initial orientation, namely a relatively small axial displacement in horizontal to vertical orientation. Thus, rather than being placed under the vertically oriented arched spine, it sits at a distinct tilt. The development of the sacrovertebral angle and the lumbar forward convexity (lordosis) was designed to allow the trunk to be held erect, despite the position of the sacrum. This misalignment between sacral and vertebral orientation is the focus of this project.
The major aim of this study is to develop a new, easy to use method for assessing sacral anatomical orientation (SAO), which can be applied both to skeletal material and living subjects (CT).
The other aims of the project were: 1) to create a new database for this new measurement. 2) to describe the relationship between sex, ethnicity and age on the one hand, and SAO on the other and, finally 3) to describe the possible relationship between SAO on the one hand, and spinal anomalies and deformities on the other.
Sacral anatomical orientation (SAO) was defined as the angle created between the intersection of a line running parallel to the superior surface of the sacrum and a line running between the anterior superior iliac spine (ASIS) and the anterior-superior edge of the symphysis pubis. SAO was measured using a specially designed mechanical measurement tool and a 3D digitiser.
In the first stage a study was conducted on skeletal material (from the Hamann-Todd Osteologic Collection, curated at the Cleveland Museum of Natural History, Cleveland, Ohio, USA). In the second stage a study was made of 3-D images of the bony pelvis (Model: Philips Brilliance 64, thickness of sections: 1-2 mm, MAS: 80-250) originally performed on patients arriving for abdomen or pelvis examination at the Radiology Department, Carmel Medical Center, Haifa,Israel. The 3-D character of the software enabled me to measure the angle, taking into consideration the 3-D character of the pelvis and its three-dimensional relations with the sacrum on the one hand, and with the femoral heads on the other.
SAO was compared to the most used method in the clinical field, namely, pelvic incidence (PI).
The average SAO angle in humans is 49.01°±9.52. Mean pelvic incidence was 54.01°±12.64.

The main finding was that SAO angle in humans is highly variable but there is a normal range (36°-65°), which I termed “Human zone”. Therefore, SAO is an individual optimal solution between stability and mobility, and not a canalized characteristic (compared to femoral neck-shaft angle, for example).
The mean sacral anatomical orientation for the age cohort of 13-18 years is 60.3°±6.9, implying a highly vertically oriented sacrum among adolescents. With age, however, the sacrum becomes more horizontally oriented (by 15°). It is suggested that a more horizontally oriented sacrum is related to the development of spinal deformities (in adolescence) and of spinal anomalies in the old age (e.g. spondylolisthesis).
It was also found that SAO is independent of ethnicity and sex.
The newly suggested parameter (SAO) may be an important tool in defining the sagittal shape of the spine and understanding its relationship with spinal disease.

Pelvis architecture and Urinary Incontinence in women

Objective: To examine anatomical features in the pelvic bones and muscles in women with urinary incontinence (UI).
Material and methods: Between October 2005 and January 2006, 212 women underwent pelvic computerized tomography in our center. Preceding the examination, all women completed a clinical and demographical questionnaire including detailed questions about UI. Several anatomical parameters using multi-planar reformation and 3-dimensional techniques (volume rendering) were examined. We specifically evaluated different bony parameters, pelvic floor muscles angles, densities and cross sectional areas. 46.5% had UI and the reminder served as the control group. A logistic regression-model was used to evaluate risk factors for UI.
Results: The mean age was 55.5 years (range 19-90). Women who suffered from UI were older (60.97 vs. 50.77 years, p<0.0001), with higher body mass index (27.65 vs. 25.49, p<0.01), had more previous hysterectomies (21.5% vs. 6.5%, p<0.005), underwent more pelvic irradiation (9.7% vs. 1.8%, p<0.05) and had more diabetes mellitus (31.2% vs. 13.1%, p<0.005). Patient's age and previous hysterectomy were found to be the major clinical risk factors for UI (OR 1.029, p=0.002; OR 2.94, p=0.024, respectively). Logistic regression analysis on all clinical and morphological variables yielded the following risk factors: pelvic-inlet diameter (OR 1.216, p<0.0001), pelvic-inlet AP diameter (OR 1.109, p=0.003), pelvic-outlet diameter (OR 1.077, p=0.011) and transverse perineal muscle cross section diameter (OR 0.773, p<0.0001).
Conclusions: Pelvic inlet and outlet dimensions are major risk factors for developing UI in women. These findings may lead to a better comprehension of the pathophysiology of UI in women.

Osseous Changes With Age In The Vertebral Foramen Of The Cervical Spine (C3-C7): A Skeletal Population Study

Spinal stenosis is defined as narrowing of the vertebral canal/vertebral foramen. Spinal stenosis of osseous origin is recognized when the Torg ratio (sagittal diameter of the spinal canal/ midcervical sagittal vertebral body diameter) is smaller than 0.8. Stenosis, in general, may lead to compression on the spinal cord and as a result to pain, finger numbness, clumsiness etc. Little is known on age related degenerative bony changes in the cervical vertebrae which may lead to local stenosis
The aim of the current study was to study the size and shape of cervical vertebral foramen (C3-C7) and the ways age related degenerative osseous changes impinge on the vertebral foramen diameter. Cervical vertebrae (C3-C7) of 277 males and females individuals of various ages and ethnic origins were studied. Morphometric data was collected using 3-D digitizer (Micro-scribe device). The size and shape of the cervical vertebral foramen varied considerably from C3 to C7. The upper cervical vertebrae manifest a rounded-shaped foramen, while the lower ones have a pronounced oval-shape appearance. In Caucasians, the vertebral foramen in C3- C5 is longer (A-P) then in African-Americans. Age related changes which greatly hamper the size of the vertebral foramen were found only in African-American males (C4-C5) and African-American females (C6). No correlation was found between the Torg ratio and age.
In conclusion, age related osseous changes have only minor impact on the size and shape of the cervical vertebral canal. Much of cervical stenosis, therefore, is due to degenerative changes in the soft tissue.