Comparison of Optic Canal Diameter in Children With Malignant Infantile Osteopetrosis and Normal Children and the Effects of Hematopoietic Stem Cell Transplantation on the Optic Canal Diameter

Three-dimensional anatomical analysis of the optic nerve canal with virtual model based on CBCT

The optic nerve canal (ONC) is a fine skeletal structure that contains the optic nerve. However, it has not been thoroughly examined. This necessitates establishing a baseline knowledge of the geometrical and volumetric parameters of the ONC. The data of twenty patients who received a cone beam computed tomography examination were prepared using a voxel-based segmentation. The measurement was performed separately by two examiners on virtual skull models in stereolithography format in Geomagic Wrap®. The results showed that the volume of the ONC varied between 92.48 mm3 and 162.7 mm3 (M = 123.46 mm3, SD = 26.61 mm3). Sex-specific statistically significant differences in volume were detected only for the right side. The angle of the ONC to the skull base was independent of the diameter of the canal. Both the intrarater and interrater comparisons of the measurements showed high values of reproducibility of the results. This study showed that a virtual anatomical model provides a feasible and reliable method to investigate the ONC. The examination technique could have a wider range of application in anthropology and application in clinical medicine. Advances in the automation of radiological diagnostics and the digital analysis of X-ray images could help to reduce examination times.

Optic Canal Diameters According to Age in the Pediatric Population

PURPOSE

To determine the normal range of optic canal diameters in the Turkish pediatric population.

METHODS

Brain, orbital, and maxillofacial computed tomography examinations were evaluated retrospectively. Children with cranial bone disorders affecting the bone structure of the optic canal were excluded from the study. Oblique axial and oblique sagittal multiplanar reformatted images were created in accordance with the axis of the optic canal on both sides, and measurements were taken from the shortest transverse and craniocaudal diameters of the optic canal in these images.

RESULTS

Two hundred computed tomography examinations were evaluated. One hundred two of the patients were female and the rest were male. Patient ages ranged from 1 to 211 months (mean ± standard deviation: 86.42 ± 65.39 months). There was no significant difference between the transverse and craniocaudal optic canal diameters between sexes (P > .05). Therefore, the analyses were reevaluated in the entire patient series, regardless of sex. No significant correlation was found in the correlation test performed between optic canal diameters according to the age of the patients. No statistically significant difference was observed between the right and left optic canal diameters.

CONCLUSIONS

The determination of normal values of tissues, structures, and organs that differs with age has an important role in pediatric radiology. The authors believe that the determination of normal optic canal diameters according to certain age groups will meet the needs of daily practice. [J Pediatr Ophthalmol Strabismus. 2021;58(5):319-323.].

Successful total hip arthroplasty for autosomal dominant osteopetrosis complicated by hip osteoarthritis: A case report and review of the literature

Osteopetrosis is a rare congenital bone disorder, characterized by systemic osteosclerosis due to a deficiency of or functional defect in osteoclasts. Autosomal dominant osteopetrosis (ADOP) is the most common form with a late onset, a stable condition, relatively few symptoms and a good prognosis. Few studies to date have reported successful total hip arthroplasty (THA) in patients with ADOP and its operative difficulties. We herein describe a case of left hip osteoarthritis in a patient with OP via THA in order to share our experience during the treatment process. The patient was a 52-years-old female with osteopetrosis who was referred to our department due to a history of left hip pain with activity limitation for 20 years. The patient reported no history of fracture or family history. The patient underwent THA in the left hip. At the 6-month, 1- and 2-year follow-up, the components were in a good position and the patient remained asymptomatic and pain-free. Therefore, THA may be a feasible treatment option when patients with ADOP suffer from painful hip osteoarthritis.