ABSTRACT
INTRODUCTION: While odontoid fractures frequently lead to non-union in elderly population, they are relatively rare in the younger age group. We present our management of a rare case of neglected odontoid fracture in an ankylosed spine of a young female. CASE REPORT: A 28-year-old female presented to our emergency department with neck deformity after a history of fall 1 year back. She presented with clinical symptoms and signs of cervical myelopathy. Diagnostic imaging confirmed ankylosis of the cervical spine with a non-union of the odontoid fracture with atlantoaxial instability and kyphosis. She was treated with anterior release of the odontoid through a standard Smith-Robinson approach, anatomical reduction, and posterior occipitocervical stabilization and fusion. CONCLUSION: Non-union with a malpsitioned odontoid fracture in an ankylosed spine can be addressed by an anterior release and reduction with posterior fusion with good functional outcome.
ABSTRACT
INTRODUCTION: Cervical spine injuries in the children are unusual, and an incidence rate of 1.5-3% of all the spinal fractures has been reported. The cartilaginous end plate between the dens and the body of the axis usually ossifies at the age of 5-7 years. This anatomical characteristic has been attributed to odontoid synchondrosis fractures in young children. However, odontoid process fractures are rare in children and only few cases have been reported in literature. CASE REPORT: We report a case of a displaced odontoid synchondrosis fracture in a 2-year-old girl with anterior subluxation of C1 over C2 vertebra. This was treated with a posterior atlantoaxial fusion using sublaminar wiring. Immediate post-operative radiography showed partial reduction of the displaced odontoid fragment on C2 body with residual step deformity with angulation at the fracture site. Follow-up at 1 year showed excellent remodeling. CONCLUSION: Synchondrosis fractures of the odontoid are rare and usually found in children under 7 years of age. Most of these patients can be treated by external immobilization alone. However, in small children with significant displacement and angulation, posterior C1-C2 fusion is a better option providing more stability. Furthermore, one can expect significant remodeling of the fracture within this population.
ABSTRACT
OBJECTIVE: To evaluate 3-dimensional magnetic resonance imaging (MRI) of Kambin's safe zone to calculate maximum cannula diameter permissible for safe percutaneous endoscopic lumbar discectomy. METHODS: Fifty 3D MRIs of 19 males and 31 females (mean, 47 years) were analysed. Oblique, axial and sagittal views were used for image analysis. Three authors calculated the inscribed circle (cannula diameter) individually, within the neural (original) and bony Kambin's triangle in oblique views, disc heights on sagittal views and root to facet distances at upper and lower end plate levels on axial views and their averages were taken. RESULTS: The mean root to facet distances at upper end plate level measured on axial sections increased from 3.42±3.01 mm at L12 level to 4.57±2.49 mm at L5S1 level. The mean root to facet distances at lower end plate level measured on axial sections also increased from 6.07±1.13 mm at L12 level to 12.9±2.83 mm at L5S1 level. Mean maximum cannula diameter permissible through the neural Kambin's triangle increased from 5.67±1.38 mm at L12 level to 9.7±3.82 mm at L5S1 level. The mean maximum cannula diameter permissible through the bony Kambin's triangle also increased from 4.03±1.08 mm at L12 level to 6.11±1 mm at L5S1 level. Only 2% of the 427 bony Kambin's triangles could accommodate a cannula diameter of 8mm. The base of the bony Kambin's triangle taken in oblique view (3D MRI) was significantly higher than the root to facet distance at lower end plate level taken in axial view. CONCLUSION: The largest mean diameter of endoscopic cannula passable through "bony" Kambin's triangle was distinctively smaller than the largest mean diameter of endoscopic cannula passable through "neural" Kambin's triangle at all levels. Although proximity of exiting root to the facet joint is always taken into consideration before PELD procedure, our 3D MRI based anatomical study is the first to provide actual maximum cannula dimensions permissible in this region.
