Chronic obstructive pneumonia caused by a vertebral body osteophyte

Effects Induced by Osteophytes on the Strain Distribution in the Vertebral Body Under Different Loading Configurations

The mechanical consequences of osteophytes are not completely clear. We aimed to understand whether and how the presence of an osteophyte perturbs strain distribution in the neighboring bone. The scope of this study was to evaluate the mechanical behavior induced by the osteophytes using full-field surface strain analysis in different loading configurations. Eight thoracolumbar segments, containing a vertebra with an osteophyte and an adjacent vertebra without an osteophyte (control), were harvested from six human spines. The position and size of the osteophytes were evaluated using clinical computed tomography imaging. The spine segments were biomechanically tested in the elastic regime in different loading configurations while the strains over the frontal and lateral surface of vertebral bodies were measured using digital image correlation. The strain fields in the vertebrae with and without osteophytes were compared. The correlation between osteophyte size and strain alteration was explored. The strain fields measured in the vertebrae with osteophytes were different from the control ones. In pure compression, we observed a mild trend between the size of the osteophyte and the strain distribution (R² = 0.32, p = 0.15). A slightly stronger trend was found for bending (R² = 0.44, p = 0.075). This study suggests that the osteophytes visibly perturb the strain field in the nearby vertebral area. However, the effect on the surrounding bone is not consistent. Indeed, in some cases the osteophyte shielded the neighboring bone, and in other cases, the osteophyte increased the strains.

Cervical spinal cord infarction due to impingement of an anomalous right vertebral artery by thoracic osteophyte

INTRODUCTION

Spinal cord infarction in a young, otherwise healthy individual is a rare occurrence. The anterior spinal artery and posterior spinal arteries are the primary contributors to the vascular supply of the cervical supply, and these arteries arise as descending branches of the vertebral arteries. Historically, many cases have demonstrated individual variations in the vertebral arteries, such as differences in dominancy, patency, origin, and insertion. The clinical significance of these variations remains poorly understood.

CASE PRESENTATION

We present a patient who sustained a spinal cord infarction at C2-C5 resulting in incomplete quadriplegia. The mechanism of injury was unclear, although the patient reported an awkward jumping motion earlier that day that preceded the onset of upper extremity weakness. After resolution of the acute phase, he was diagnosed with "Man-in-the-Barrel" syndrome. Angiographic evaluation revealed an anomalous non-dominant right vertebral artery with several pathological features: origin at the descending aorta, insertion into the right posterior inferior cerebellar artery, and impingement along its course by an anterior thoracic osteophyte.

DISCUSSION

The vertebral arteries play an important role in the vascular supply of the cervical spine. While vertebral artery pathology such as dissection or occlusion have been documented in rare cases to result in spinal cord infarction, this case illustrates an example of clinically significant sequelae that can occur in the setting of anomalous vertebral arteries even in the absence of occlusion or dissection. Furthermore, to our knowledge this is the first reported case of a spinal cord infarction resulting from osteophytic vertebral artery impingement.

A Case of a Paracardial Osteophyte Causing Atrial Compression

Osteophytes are pointed or beaked osseous outgrowths at the margins of articular surfaces that are often associated with degenerative changes of articular cartilage. They are the most common aspect of osteoarthritis and they infrequently cause symptoms by compression of the adjacent anatomic structures, such as nerves, vessels, bronchi, and esophagus. We present here a rare case of a patient with a left atrial deformation by a large osteophyte.

A new osteophyte segmentation algorithm using partial shape model and its applications to rabbit femur anterior cruciate ligament transection via micro-CT imaging

Osteophyte is an additional bony growth on a normal bone surface limiting or stopping motion at a deteriorating joint. Detection and quantification of osteophytes from CT images is helpful in assessing disease status as well as treatment and surgery planning. However, it is difficult to distinguish between osteophytes and healthy bones using simple thresholding or edge/texture features due to the similarity of their material composition. In this paper, we present a new method primarily based active shape model (ASM) to solve this problem and evaluate its application to anterior cruciate ligament transection (ACLT) rabbit femur model via CT imaging. The common idea behind most ASM based segmentation methods is to first build a parametric shape model from a training dataset and apply the model to find a shape instance in a target image. A common challenge with such approaches is that a diseased bone shape is significantly altered at regions with osteophyte deposition misguiding an ASM method and eventually leading to suboptimum segmentations. This difficulty is overcome using a new partial ASM method that uses bone shape over healthy regions and extrapolates it over the diseased region according to the underlying shape model. Finally, osteophytes are segmented by subtracting partial-ASM derived shape from the overall diseased shape. Also, a new semi-automatic method is presented in this paper for efficiently building a 3D shape model for an anatomic region using manual reference of a few anatomically defined fiducial landmarks that are highly reproducible on individuals. Accuracy of the method has been examined on simulated phantoms while reproducibility and sensitivity have been evaluated on CT images of 2-, 4- and 8-week post-ACLT and sham-treated rabbit femurs. Experimental results have shown that the method is highly accurate ( R2 = 0.99), reproducible (ICC = 0.97), and sensitive in detecting disease progression (p-values: 0.065,0.001 and < 0.001 for 2- vs. 4, 4- vs. 8- and 2- vs. 8-weeks, respectively).