Treatment of lumbar degenerative disease with modified transforaminal lumbar interbody fusion

[Objective] To explore the clinical application and result of modified transforaminal lumbar interbody fusion(TLIF)for the treatmentof lumbar degenerative disease.[Method] From October 2003 to May 2005,25 patients(29 levels)suffering from lumbar degenerative disease were treated with modified TLIF.The modification included expansile decompression of vertebral canal combination with TLIF and pedicle screw instrumentation.There were 17 males and 8 females with average age of 54.6 years,ranging from 24 to 65 years.The preoperative diagnosis included lumbar degenerative spondylolisthesis(11 cases,GradeⅠtoⅡ),lumbar intervertebral disc protrusion combined with segmental instability(6 cases)and lumbar spinal stenosis(8 cases).Expansile decompression of vertebral canal was applied as follows:total inferior facet process and inner half superior facet process of the trouble side were resected firstly,the compression for the nerve root caused by degenerative articular process and lateral recess stenosis was relieved.Then half spinous process and lamina were resected while decompression of the vertebral canal was expanded to opposite side until the never root was decompressed satisfactorily.Care must be taken to avoid over resecting which lead to isthmic breaking.In the end,TLIF was performed according to normal procedure after the decompression of vertebral canal being accomplished.[Result]The lateral,AP,flexion-extension X-ray films were taken at 3,6 months and 1 year after operation to evaluate the fusion,Simmons method and Denis pain measurement and JOA scoring were adopted to determine the results.The intraoperative blood loss ranged from 310 to 820ml(mean,530ml),and total operative time ranged from 110 to 210min(mean,165min).Blood transfusion was carried out in 6 patients(range,400 to 800 ml).All patients were followed up for 12 to 36 months(mean,18.4 months),no failure of pedicle screws and cage migration occurred.One cage subsidence and 2 nonunion were shown in plain X-ray films,3 patients complained of worsening numbness in legs in side which TLIF was performed.The rate of improvement was 92% in all patients according to above evaluation methods.[Conclusion]The modified TLIF expands the indications for TLIF.Operative procedure can be performed more easily and safely with less complications.The clinical results are satisfactory in some selected patients suffering from lumbar degenerative disease according to the author's experience.