Objective To analyze the effectiveness of transforaminal lumbar interbody fusion (TLIF) for failed back surgery syndrome (FBSS). Methods Between October 2003 and December 2007, 36 patients with FBSS were treated with TLIF. There were 19 males and 17 females with an average age of 52.6 years (range, 46-68 years) and an average disease duration of 1.6 years (range, 3 months-15 years). Of 36 patients, reoperation was performed in 25, 10 received 3 operations,and 1 had 5 operations. A total of 50 segments were involved in fusion, including L4, 5 in 12 cases, L5, S1 in 10 cases, L3, 4 and L4, 5 double segments in 8 cases, and L4, 5 and L5, S1 double segments in 6 cases. According to X-ray films, CT, and MRI examination, 12 patients were diagnosed as having lumbar instabil ity secondary to total laminectomy, 18 as having recurrence of lumbar disc protrusion, and 6 as having recurrence of lumbar spondylol isthesis. Results Dural rupture occurred in 1 case and was repaired by suturing without cerebrospinal fluid leakage was observed; 1 had deep incision infection of Staphylococcus; and 1 had transient single irritation sign because of hematoma formation and was cured after symptomatic treatment. The other incisions healed by first intention. No patients had permanent nerve injury or deterioration. Thirty-three cases were followed up 18-72 months (mean, 35.2 months). At 12 months, all the operated segments reached interbody fusion, and no breakage of screw or Cage dislocation occurred. Japanese Orthopaedic Association (JOA) scores showed significant difference (t=2.45, P=0.01) between before operation (14.2 ± 4.1) and 18 months after operation (23.9 ± 2.6). The rate of cl inical improvement was 90.9% (23 cases of excellent, 7 cases of good, 3 cases of acceptable). Conclusion The TLIF simpl ifies the manipulation of lumbar revision surgery and decreases the operation risk and the operative compl ications for the treatment of FBSS.
Objective To analyze the cl inical effects of modified transforaminal lumbar interbody fusion (TLIF) for the treatment of lumbar degenerative disease. Methods From October 2003 to December 2006, 33 patients with lumbar degenerative disease (L3-S1) were treated by modified TLIF. There were 14 males and 19 females with an average age of 52.2 years(33 to 70 years). The median disease course was 1.8 years (4 months to 15 years). A total of 42 levels were fused, including 24 cases of single level and 9 cases of double levels. The results of preoperative diagnosis were lumbar degenerative spondylol isthesis with stenosis (8 cases), isthmic spondylol isthesis (5 cases), degenerative lumbar stenosis (16 cases), huge herniated disc with segmental instabil ity (3 cases) and failed back surgery syndrome (1 case). During the modified TLIF procedure, total inferior facet process and inner half summit of superior facet process of TLIF side were resected to make the posterior wall of foramen opened partly. After the bone graft (3 to 5 mL) was placed into the interbody space, a single rectangle Cage was inserted obl iquely from 30° to 40° toward the midl ine. Combined with pedicle screw instrumentation, TLIF was accompl ished. Middle canal and opposite side nerve root decompression were performed simultaneously when necessary. Results Intraoperative dura mater rupture, postoperative cerebral spinal fluid leakage, deep wound infection and transient nerve root stimulation occurredin 1 case respectively, and were all recovered after treatment. No patients had permanent neurologic deficit or aggravation. All patients were followed up for 20 to 58 months (mean 27.2 months). At the follow-up after 1 year postoperatively, all the operated segments achieved fusion standard and no broken screw or Cage dislocation occurred. All 13 cases of spondylol isthesis were reduced thoroughly and maintained satisfactorily. Nineteen patients remained sl ight chronic back pain. There was significant difference (P lt; 0.05) in JOA score between preoperation (14.9 ± 5.1) and postoperation (25.9 ± 3.0). The rate of cl inical improvement was 80.5% (excellent in 24 cases, good in 7 cases, and fair in 2 cases). Conclusion The modified TLIF carries out the less invasive principles in opening operations, simpl ifies the manipulation and expands the indication of TLIF to some extent, and the cl inical results for the treatment of lumbar degenerative disease is satisfactory.
Objective To investigate the cl inical appl icabil ity and value of internal fixator for the reconstruction of lumbar isthmus in the treatment of lumbar vertebral spondylolysis and to lay a fundation for its cl inical appl ication. Methods Sixteen healthy goats weighing 22.65-31.22 kg were selected to establ ish the models of vertebral spondylolysis at L5, which thereafter were randomized into two groups (n=8): bone graft group in which 0.8-1.1 g fresh autogenous bone was transplanted into the isthmus spondylolysis area, and internal fixation with bone graft group in which internal fixator was installed before transplanting 0.8-1.1 g fresh autogenous bone into the isthmus spondylolysis area. All animals were killed 8 weeks after operation to receive imaging, topographic anatomy and histology detection. Meanwhile, biomechanics test was performed by using 5 donated vertebral body specimens (4 males and 1 female aged 35-51 years old). The left isthmus of L5 vertebra was transected to serve as lumbar vertebral spondylolysis model. A mini-displacement sensor was put at the transected ends of the isthmus. Then loading was conducted with a constant velocity of 2 mm/min by electronic omnipotent tester simulating the direction of fixation force of the internal fixator, and the deformation value of the transected ends was collected by a dynamic data collector and analyzer. The loading wascontinued until the vertebra specimens were damaged. The deformation of displacement sensor and the closure of transected ends of the lumbar isthmus were observed. Results All the goats behaved normally shortly after operation, and no nerve injury induced by operation and no wound infection occurred. Bilaterally obl ique X-ray films of lumbar vertebra and topographic anatomy 8 weeks after operation showed the fusion rate of the internal fixation and bone graft group and the bone graft group was 100% and 62.5%, respectively, indicating there was a significant difference (P lt; 0.05). Histology observation showed 3 goats in the bone graft group presented empty bone trabecula, empty bone lacuna and the disappearance of osteocytes at the transected ends of lumbar isthmus; while in the internal fixation and bone graft group, the bone trabecula grew into cancellous structures with hematopoietic and fatty bone marrow tissue inside, and parts of the bone trabecula had various degrees of mosaic-l ike pattern. During the upload, the biomechanics test and data processing results showed when the external load was 40 N, the deformation of displacement sensor was identified and the gap between the transected ends of lumbar isthmus started to close; then with the increase of external load, the displacement sensor tended to ascend in a l inearity manner; while when the external load was 212 N, the displacement sensor had no further deformation, the gap between the transected ends of lumbar isthmus wascompletely closed, and the pressor effect appeared. Conclusion The internal fixator for the reconstruction of lumbar isthmus has mechanical effects of stabil izing and elevating pressure with a high fusion rate.