Surgical treatment for lower lumbar burst fractures

English Keywords:Burst fractures  Low lumbar spine  Surgical treatment

English Abstract:

  【Abstract】 Objective：To investigate the surgical treatment for lower lumbar（L3-L5） burst fractures.Method：The clinical data of 14 patients with lower lumbar burst fractures from January 1996 to October 2006 treated surgically were reviewed retrospectively.There were 12 males and 2 females with the age ranging from 18 to 63 years（mean age，32.7 years）.At time of admission，1 patient had no neurological deficit，4 patients had radiculopathy，1 patient had conus medullaris syndrome and 8 had cauda equina injuries which included grade A in 2，B in 1，C in 3 and D in 2 according to ASIA classification.7 fractures were identified at L3，5 at L4 and 2 at L5.The mean initial Cobb′s angle ranged from -20° to 12°（mean angle，-4.1°，negative value means lordosis）.8 patients were complicated with other injuries which included 4 additional spine stable fractures，1 pelvic fracture，1 subtrochanteric fracture，2 rib fractures，3 tibial and fibular fractures and 2 calcaneus fractures.1 patient with L3 burst fracture and cauda equina injury（ASIA grade C） underwent anterior corpectomy，intervertebral fusion and Kaneda instrumentation.13 patients experienced posterior decompression，pedicle screws instrumentation and posterolateral（12 cases） or intervertebral fusion（1 case）.Neurological function，radiographs and ambulatory status were evaluated at final follow-up.Result：The operation time ranged from 3.5 to 7 hours（average，5 hours） with blood loss ranging from 600ml to 2200ml（average，1258ml）.No patients presented with neurological deterioration regardless of surgical approach.2 patients suffered cerebrospinal fluid leakage.No skin incision infection and other severe complication were noted.At 2 weeks after operation，the Cobb′s angle ranged from -27° to 7°（average，-12.4°），which showed statistical significance compared with preoperation（P＜0.01）.4（28.6%） patients required revision surgery after initial surgical stabilization.2 cases had internal fixation removal due to low back pain.1 patient undergoing anterior surgery initially experienced posterior nerve exploration due to pain in lower extremities.1 patient required posterior exploration and nerve root release because of incorrect reduction and anal pain after initial surgery.All patients had symptoms improved partially after revision surgery.The followed up period ranged from 24 to 42 months（average，34.1 months）.At final follow-up muscle strength in patients with radiculopathy improved one or two grade.Patient with conus medullaris syndrome recovered to routine activity and bladder function.Neurological function of 3 patients with cauda equina injuries remained no change.The other 5 patients had at least one ASIA grade improvement of neurological function.There was 1.7° loss of lordosis at final follow-up，but no statistical significance was noted compared with that at 2 weeks postoperation（P＞0.05）.13 patients got bony union.1 patient suspected to having pseudarthrosis was left alone due to no discomfort.No instrument failure was noted.All patients were able to community ambulation with or without brace at final follow-up.Conclusion：When surgical treatment is indicated for lower lumbar burst fractures，posterior approach should be considered first.Surgical stabilization can ensure good deformity correction，but reoperation can not be avoided due to high rate of low back pain and low extremity and anal pain.