Factors in Selection of Surgical Approaches for Lower Lumbar Burst Fractures

하부 요추 방출 골절의 수술방법 결정시 고려 요인들

Objectives : Burst fracture of the lower lumbar spine(L3-L5) is rare and has some different features compare to that of thoracolumbar junction. Lower lumbar spine is flexible segments located deeply, and has physiologic lordosis. All of these contribute to making surgical approach difficult. Generally, lower lumbar burst fracture is managed either anteriorly or posteriorly with various fixation and fusion methods. But there is no general guideline or consensus regarding the proper approach for such lesion. We have tried to find out the influencing factors for selecting the surgical approach through the analysis of lower lumbar burst fractures treated for last 4 years(1994.3-1998.3). Method : This study includes 15 patients(male : 10, female : 5, age range 20-59 years with mean age of 36.7 years, L3 : 8 cases, L4 : 5 cases, L5 : 2 cases). Patients were classified into anterior(AO) and posterior operated(PO) groups. We investigated clinical findings, injured column, operation methods, and changes in follow-up radiologic study (kyphotic angle) to determine the considerable factors in selecting the surgical approaches. Results : There were 5 AO and 10 PO patients. Anterior operation were performed with AIF with Kaneda or Z-plate and posterior operation were done with pedicle screw fixation with PLIF with cages or posterolateral fusion. Canal compression was 46.6% in AO and 38.8% in PO. The degree of kyphotic angle correction were 10.7 degree(AO) and 8.5 degree(PO), respectively. There was no statistical difference between anterior and posterior operation group. All patients showed good surgical outcome without complications. Conclusion : Anterior operation provided good in kyphotic angle correction and firm anterior strut graft, but it difficulty arose in accessing the lesions below L4 vertebra. While posterior approach showed less correction of kyphotic angle, it required less time and provided better results for accompanied adjacent lesion and pathology such as epidural hematoma. The level of injury, canal compression, biomechanics, multiplicity, and pathology are considered to be important factors in selection of the surgical approach.