ABSTRACT
PURPOSE: This study examined the morphological characteristics of the thoracic and lumbar vertebrae of normal Koreans and the factors causing breakage of the pedicular wall by measuring the thoracolumbar vertebrae relative to the pedicle screw insertion. MATERIALS AND METHODS: The effect of the pedicle screw shape on the pedicle wall integrity of 56 normal Koreans was examined by performing a computer simulation of the inserting pedicle screws into the pedicle wall by superimposing the graphical images of the screws onto the CT scan images. RESULTS: Because the inner pedicle diameters of the most thoracic vertebrae from T4 to T10 were <5 mm, most pedicles of the thoracic vertebrae were expected to be broken after inserting the 5 mm-diameter cylindrical screws. The pedicles of the thoracic and lumbar vertebrae were classified into 6 groups by performing the cluster analysis using morphometric parameters. Group 1 was labeled "relatively narrow". Group 2 "moderate". Group 3 "wide and angular". Group 4 "severly narrow and short", Group 5 "long", and group 6 "relatively wide and angular". The simulation showed the pedicles of groups 1 and 4 to be too narrow for the 5 mm-diameter cylindrical screws to preserve the pedicular wall integrity. CONCLUSION: The pedicles of the vertebra of Koreans are similar in size to those of Caucasians. Personal morphological characteristics of the pedicles as well as their sizes and levels of the vertebrae are believed to be the significant factors that can cause the breakage of the pedicular wall.
ABSTRACT
We have reviewed seven cases of fracture-separation of the distal humeral epiphysis, one of which was initially misdiagnosed as a fracture of the lateral condyle. There were difficulties in making the diagnosis. The injury must be distinguished from an elbow dislocation and a fracture of the lateral humeral condyle. All seven patients revealed posteromedial displacement of the distal humeral epiphysis on initial x-rays. Three patients were treated by closed reduction and cast immobilization, and four patients by open reduction and internal fixation. All three patients with conservative treatment had slight cubitus varus (under 5 degrees). Two patients with operative treatment had significant deformities of the elbow, one 25 degrees of valgus and one 20 degrees of varus. In treatment of these injuries, accurate evaluation of the state of reduction is most important. We got acceptable results with a conservative treatment.