Posterior Lumbar Apophyseal Fracture / 대한정형외과학회잡지

ABSTRACT

Posterior lumbar apophyseal fracture characterized by osteochondral fragments from posterior rim of a lumbar vertebral body, has often been misdiagnosed as herniated disc or spinal stenosis due to its similarity of symptoms. But recent use of CT scan facilitated the diagnosis of the lesion as a separate entity. This study was performed to verify the clinical characteristics, to find out the mechanism of injury and to determine the most effective method of diagnosis and treatment. Authors reviewed 17 patients(14 male, 3 female) who were subjected to surgical treatment at Department of Orthopaedic Surgery, Seoul National University Hospital for posterior lumbar spophyseal fracture during the period of 1990-1992, and followed up for average of 1 year and 6 months(range 1 to 3 years). Thirteen patients (76%) were related to a history of trauma or strenuous physical activity prior to the onset of symptoms. The mechanism of injury was the rapid flexion with axial compression in 7, hyperextension in 4, and pure axial compression in 2 patients. The mean age at the time of injury was 20 years(range 10 to 31 years). All patients presented low-back pain radiating to lower extremities and 11 patients showed neurogenic intermittent claudication. The mean age at the time of surgical intervention was 23 years and 10 months(range 15 to 31 years), and the mean duration of symptoms was 3 years(range 2 months to 13 years). Simple X-ray revealed the lesion in only 3 cases but CT scan demonstrated the characteristic osteochondral fragment displaced posteriorly into the spinal canal and the corresponding defect with degenerative changes in all patients. The fracture occured through the superior apophyseal rim of L5 in 9 superior rim of L4 in 3, inferior rim of L4 in 2, inferior rim of L5 in, superior rim of L2 in 1, and superior rim of L1 in 2 patients. Two patients had concomitant fractures at two levels. All patients except one were treated with posterior decompression including the removal of the displaced fragment and posterolateral fusion with pedicular screws was carried out to prevent further degenerative change and instablilty. One patient with the lesion at the superior rim of L1 was treated by anterior decompression and fusion. All patients showed relief of pain and claudication with satisfactory results. One patient had partial tear of L4 root with slight weakness of greater toe dorsiflexion, but it recovered in 4 months. In conclusion, posterior lumbar spophyseal fracture predominantly affected young males and the most common causative mechanism was rapid flexion with axial compression. The CT scan facilitated identification of the lesion. The most frequently affected site was the superior rim of L5. Satisfactory results could be achieved bvy adequate posteriior decompression with the removal of the fragment and posterolateral fusion with pedicular screws.