Transforaminal Lumbar Interbody Fusion Clinical and Radiologic Results and Complications in 50 Consecutive Patients

Transcription

1 Med. J. Cairo Univ., Vol. 80, No., March: 5-0, 0 Transforaminal Lumbar Interbody Fusion Clinical and Radiologic Results and Complications in 50 Consecutive Patients MOHAMED Y. EL-QAZAZ, M.D., Ph.D. and TARIQ ELEMAM ELSHAFEY, M.D., Ph.D. The Department of Neurosurgery, Faculty of Medicine, Suez Canal University, Ismailia, Egypt Abstract Objectives: To assess fusion rate and clinical outcomes in patients with degenerative segmental instability who were operated by transforaminal lumbar interbody fusion. Methods: Fifty consecutive adult patients were analyzed. Patient participation was based on the presence of degenerative segmental instability. They were operated for instrumented spinal stabilization with screws and TLIF between February 007 and September 0. Participants were evaluated preoperatively and post-operatively at,6,9, and month intervals. Pain was scored by a VAS for both lower limb and back pain both preoperatively and postoperatively. The clinical outcomes were assessed using the Prolo economic and functional rating scale and the fusion status was assessed using radiological criteria. Results: A total of 50 patients were included. Patients had preoperative symptoms duration for. ±. years. Of the 50 patients, 4 underwent single-level fusion: Seven patients underwent a two-level fusion and one patient underwent a three-level fusion from L-S. The average hospital stay was 4.7±.8 days. By months follow-up period, 74% of the study group expressed clinical success. Seventy percent of patients were considered to have undergone successful fusion. Conclusions: TLIF is safe, fusion rate is high and patient outcome compares favorably to literature series. Proper patient selection remains the key to satisfactory spinal fusion outcome. Key Words: Degenerative disc disease Transforaminal lumbar interbody fusion (TLIF) Spinal stabilization Spinal fusion Segmental instability. Introduction LUMBAR interbody fusion has many advantages over other forms of stabilization and fusion. An interbody graft is better suited to resist axial loads, Abbreviations used in this paper: LBP = Low back pain. TLIF = Transforaminal lumbar interbody fusion. PLIF = Posterior lumbar interbody fusion. VAS = Visual analogue scale. Correspondence to: Dr. Mohamed Youssef El-Qazaz, myalqazaz@hotmail.com prevent movement across a motion segment, and provide structural support because the graft is placed in vicinity of the instantaneous axis of rotation. Despite theoretical advantages of an interbody fusion, whether one type of the interbody graft or implant is superior to the other in terms of fusion rate and, more important, clinical outcome is an area of great debate []. In 98, Harms and Rolinger [] suggested the placement of bone graft, via a transforaminal route, into disc space that previously had been distracted using pedicle screw instrumentation (transforaminal lumbar interbody fusion [TLIF]). Such an approach can be accomplished without exposing more than the ipsilateral foramen, and retraction on the thecal sac is minimal. This approach can be particularly advantageous in the face of scarring after prior surgery. Moreover, the pedicle screw construct can be used dynamically to restore lumbar lordosis, while maintaining disc height with bone graft [- 5]. The ability to achieve a circumferential fusion, without substantial risk to neurological function or the need for sequential operations, would significantly broaden surgical options in the treatment of degenerative disease of the lumbar spine [6,7]. We present our clinical experience using the TLIF procedure, focusing on technique, clinical and radiological outcomes and safety. Material and Methods This study was designed as prospective, clinical study. Patients were selected to receive TLIF in an instrumented lumbar fusion. Between February 007 and September 0, at Suez Canal University Hospital (Ismailia, Egypt) a total of 50 consecutive patients indicated for TLIF with screw fixation were included. 5

2 6 Transforaminal Lumbar Interbody Fusion Clinical & Radiologic Inclusion criteria required all patients to present with degenerative segmental instability on clinical and radiological basis. Patients may have degenerative disc disease, degenerative spondylolisthesis or retrolisthesis (grade or ), previous laminectomy or discectomy, Pseudoarthrosis after other types of lumbar spine fusion. Patients should have been unresponsive to conservative management for a minimum of months. Exclusion criteria ruled out patients with general diseases that preclude surgical management (severe osteoporosis, immune suppression, malignancy and active local and/or systemic infection). Patients with morbid obesity as measured by body mass index >40, with spondylolisthesis of grades higher than grade or with epidural scarring and prior CSF leak were also excluded. Surgical technique: Patients are operated under general anesthesia in the prone position, to maintain the lumbar lordosis. Posterior midline incision is done extending slightly beyond the levels to be approached, followed by subperiostal dissection of the muscles until complete exposure of the transverse processes. Posterior decompression of the canal and vertebral foramen, as far as necessary is done. Unilateral resection of the inferior articular facet of the superior vertebra and the superior articular facet of the inferior vertebra is accomplished exposing unilaterally the intervertebral foramen. Then We Expose the posterolateral portion of the ipsilateral disc space in the topography of the vertebral foramen. Coagulation (with bipolar) of the small epidural vessels, and visualization and protection of the dura medially was followed. Pedicle screws are placed in the standard fashion followed by removal of the disc through the vertebral foramen, and also of the end plates. We distract the involved segment using rod over the screws on the opposite side, then completing the removal of the cartilagenous material inside the disc space. Harvested local bone combined with corticocancellous iliac crest autograft is packed in the disk space transforaminally. Final rods of desired length were contoured to the appropriate lordotic curve and are applied over the pedicle screws in compression. A drainage catheter is inserted. Facial, subcutaneous, and skin layers are closed. Post-operative care: The patients were advised to begin to walk one day after the surgery, wearing vest or elastic belt for comfort for months, and were usually discharged on the third or fourth day after surgery. We prescribed analgesic and muscle relaxant, and we avoided the use of anti inflammatory and tobacco. Perioperative data: Duration of surgery, blood loss, and duration of inpatient treatment were recorded. Intraoperative and perioperative complications were assessed. Clinical follow-up: Patients were followed weeks,,6,9 and months after surgery. During follow-up visit the following data were collected: Location of pain; intensity of leg and back pain according to the VAS; neurological symptoms; pain medication, complications, subsequent spinal surgery and assessment of the patient economic (activity) and functional (pain) statuses were assessed and the clinical outcome was evaluated using the Prolo economic and functional rating scale (Table ), in which there is a maximum score of 0 points. (Poor, -4; fair, 5-6; good, 7-8; and excellent, 9-0 points). Good and excellent results were considered a clinical success [8-0]. Finally patients were asked to rate their condition as improved, unchanged, or worse; they were also questioned as to whether they would undergo the same procedure again under the same circumstances. Radiological follow-up: Radiological fusion was assessed at individual levels as observed on plain radiographs that were obtained postoperatively every months to evaluate fusion. Radiological fusion was assessed according to the criteria approved by the FDA for evaluation of lumbar intervertebral fusions. (Table ) Fusion was defined as a continuous bone bridge between the vertebrae seen in at least one sagittal reconstruction []. Results Preoperative data: A total of 50 patients were included in this study. The demographic data of the study group are presented in (Table ). On average, patients had preoperative symptoms duration for. ±. years (range -0) (Table ). According to indication for surgery, patients may be separated into three subgroups. Group consisted of 4 patients with no history of surgery but with evidence of translational instability on preoperative radiographs. Group contained 7 patients with neither a history of surgery nor the presence of spondylolisthesis but with signs of degenerative disc disease. Group contained 9

3 Mohamed Y. Al-Qazaz & Tariq E. Elshafey 7 patients who had already undergone disc surgery or posterolateral fusion. A total of 58 levels were surgically treated. Of the 50 patients, 4 (84%) underwent singlelevel fusion: L4-5 ( patients), L-4 (8 patients) and L5-S ( patients). Seven (4%) patients underwent a two-level fusion: L-L5 (4 cases) and L4-S ( cases). One patient underwent a threelevel fusion from L-S. The mean values of preoperative back pain as determined by VAS (0-0) were 7.7 ±0.. The mean values of radicular pain were 8. ±.4. The mean values of preoperative economic and functional state as determined by Prolo Scale (-0) were 5. ±0.7. Perioperative data: The average operating time was 75 ±40 minutes. Average blood loss in the study group was 00± 60cm. The average hospital stay was 4.7±.8 days. Clinical outcome: In the study group, at year follow up and in comparison to the preoperative level, the mean back pain on VAS decreased significantly to.6±0.4 (range 0-6) (p<0.0) and the mean lower limb pain on VAS also decreased significantly to.5 ±0.5 (range 0-4) (p<0.0). When the outcome was evaluated by more objective means, such as the Prolo economic and functional scale, 4% ( of 50) of all the patients experienced excellent results, 50% (5 of 50) had good results, 4% ( of 50) had fair results, and 6% ( of 50) had poor results. Clinical success was considered if the patient got good or excellent score on Prolo scale ( 7 points). By months follow up period, 74% of the study group expressed clinical success. In months follow-up visit, when the patients were asked if, under the same circumstances, they would undergo the procedure again, 8% of the patients (4 patients) answered affirmatively and this is reflects their satisfaction with the results of their surgeries. Fusion outcome: Of a total of 58 levels evaluated, 7.4% (4 of 58) of these were radiographically shown to have fused at months follow-up according to the criteria mentioned in Table (). We considered a fusion to be successful in one patient when all the operated levels were fused. Seventy percent of patients were considered to have undergone successful fusion. The distribution of successful fusion was as follows: At L-4, 9 of levels; at L4-5, of 8; and at L5-S, of 7. The distribution of successful fusion for the level of the construct was as follows: One-level construct: of 4; two-level construct: of 7; and three-level construct none of one. Association between the clinical and the fusion outcomes: The fusion status was associated with the clinical outcome in the whole series. This is clear as 5/7 of patients who achieved clinical success showed fusion at months follow-up and all of the patients who achieved clinical failure showed non-fusion at months follow-up. Table (): Prolo functional economic rating scale [,]. Score Economic status: E E E E4 E5 Functional status: F F F F4 F5 Description Complete invalid No gainful occupation (including ability to do housework or continue retirement activities) Able to work but not at previous occupation Working at previous occupation on parttime or limited basis Working at previous occupation w/no restrictions of any kind Total incapacity (or worse than preoperative) Mild to moderate level of LBP &/or sciatica (or pain same as pre-operative but able to perform all daily tasks of living) Low level of pain & able to perform all activities except sports No pain, but has had or more recurrences of LBP or sciatica Complete recovery, no recurrent LBP, & able to perform all previous sports activities Table (): Radiographic observations of fusion [4]. Fusion failure 0 = No fusion done. = Collapse of construct. = Resorption of graft. = Large lucency (> mm) around entire graft. 4 = Small lucency (< mm) partially around graft. Fusion success 5 = Bone bridging fusion area. 6 = Increased density of bone. 7 = Continuous trabecular bone bridging the fusion bed.

4 8 Transforaminal Lumbar Interbody Fusion Clinical & Radiologic Table (): Demographic data, primary indication for surgery and surgically treated disc levels in the operated group of patients. Gender: Male Female Mean age/years Age group: Age 0- Age 40- Age 50- Age 60- Occupation: Light-duty work Heavy-duty work Smoking: Non-smokers Smokers Secondary Gain Issue Body mass index: * Average Non-obese Obese Previous Lumbar Surgery Diagnosis primary indication for surgery ( per patient): Degenerative spondylolisthesis Degenerative retrolisthesis Degenerative disc disease Recurrent disc herniation Pseudoarthrosis after fusion Surgically treated disc levels: One-Level Fusion L-4 L4-5 L5-S Two-Level Fusion: L-5 L4-S Three-Level Fusion: L-S Total Number of Operated levels Mean Preoperative Symptoms Duration/ Years drop postoperatively and was partially improved with physiotherapy. Five misplacement of the traspedicular screws were recorded. (Table 4) This was adjusted by repositioning of the trajectory or insertion of larger size pedicle screw if the pedicle 7 is partially violated. 49.5±9. B- Early postoperative complications: Seven neurological complications were record- 7 9 ed. Five of these were radicular pain and dysthesia 5 that had resolved within - months. Two patients 9 suffered increasing motor deficit. One of them was described before due to root injury and the other 40 one suffered added weakness of the extensor Hal- 0 lucis longus tendon that improved over the follow up. There were five superficial wound infections 4 and deep infection that required culture and 9 treatment with intravenous antibiotics. Also one 5 patient suffered iliac crest wound infection. One patient experienced postoperative DVT and the 8.4± ±. * Obesity is defined as BMI that is higher than 7.5 of the body mass index. Complications: Complications in the study group (Table 4) are divided into: A- Intraoperative complications: Three dural tears were recorded. Dural tears were repaired primarily, not requiring reoperation but prolonged the hospital stay. One patient suffered intraoperative L5 root injury during insertion of the graft. The patient developed added partial foot patient improved with the standard anticoagulation therapy. C- Late postoperative complications during the follow-up period: Three patients suffered continuous low back pain. In addition, patients needed further surgical interventions due to failure of the system of fixation. Collapse of the construct was also noted in patients most probably was caused by small amount of the bone graft in the disc space. Table (4): Complications recorded in the study group. Complications Intraoperative complications: Dural tear Root injury Hard ware related complications: Screws misplacement Early postoperative complications: Neurological complications: Radicular pain and dysthesia Increased Motor weakness Sphincter disturbance Infection: Superficial wound infection Deep wound infection Iliac crest wound infection DVT: Late postoperative complications during the follow-up: Continuous low back pain Hard ware complications: Broken Transpedicular screws Broken rod of fixation Collapse of intervertebral space No

5 Mohamed Y. Al-Qazaz & Tariq E. Elshafey 9 Fig. (): Preoperative radiology of 57-year-old male patient. To the left, MRI lumbosacral spine, T-weighted image with degenerative spondylolisthesis of the L-4 and L4-5 levels. To the right Postoperative months follow-up plain X- ray lumbosacral spine, lateral view, with transpedicular screw fixation L-5 and TLIF in both levels. There is continuous bone bridging the fusion bed. Fig. (): Preoperative radiology of a 45 year old female patient. To the left, MRI lumbosacral spine, T-weighted image with degenerative disc the L4-5 level. In the middle plain X-ray lumbosacral spine, lateral view with anterior sublaxation of the L4 vertebra over the L5. To the right, Postoperative months follow-up plain X-ray lumbosacral spine, lateral view, with transpedicular screw fixation L4-5 and TLIF. Discussion There are several different techniques of lumbar circumferential fusion. Among those, ALIF, PLIF, and more recently TLIF. In these techniques, ALIF is done through anterior approach, while PLIF and TLIF are done posteriorly. The difference is that in PLIF the access to the disc is through the canal, and in TLIF is through the inferior portion of the neurovertebral foramen. The TLIF arose as an improvement of PLIF, access sing the intervertebral disc through the far lateral portion of the vertebral foramen, by avoiding access to the disc through the vertebral canal, close to the dural sac and nerves. Lowe and Tahermia [] evaluated the cases of 40 patients operated by the TLIF technique. Twenty three patients had DDD, had spondylolysis and 4 had recurrent disc herniation. In 4 cases the arthodesis was limited to one level and in 6 it cases was done in levels. Radiological fusion was demonstrated in 95% of the cases. The clinical result was good to excellent in 88% of the patients.

6 0 Transforaminal Lumbar Interbody Fusion Clinical & Radiologic Two patients had pseudo-arthodesis and one had transitory neuropraxia. Humphreys et al. [] made a comparative study of 4 PLIF with 40 TLIF cases. Of the 4 PLIF procedures, were single level, 0 were double level and was triple level. Of the 40 TLIF, 7 were single and were double level. There were no complications with the TLIF patients. However, with the PLIF, there were 4 cases of radiculitis, case of broken hardware, case of screw loosening, cases of screw removal, nonunion requiring additional fusion, and superficial wound infection. The authors concluded that the TLIF showed to be a good alternative to PLIF with relatively less risk of complications, less operating time and hospitalization, as well as significant reduction in blood loss during operation. Hence, TLIF offers the advantage of being an efficient circumferential arthodesis through single access with the minimum risk of neural and dural lesion. At the same time, it allows posterior and foraminal decompression. Therefore, we believe that this technique should be promoted and properly employed in selected cases, especially when posterior decompression and circumferential interbody fusion of the lumbar region are necessary, as well as in many cases of DDD, recurrent disc herniation, spinal stenosis and low grade spondylolisthesis [4]. Our cases show a good experience with TLIF. Evaluation of the patients during the first 8 to 8 months after surgery showed improvement in 70% of the cases. Therefore, we believe that this technique should be promoted and properly employed in selected cases, especially when posterior decompression and circumferential fusion of the lumbar region are necessary. TLIF demonstrated its efficiency in treating cases of chronic lumbar pain with or without radiation to lower limbs, from DDD, recurrent disc herniation, low grade spondylolisthesis and iatrogenic segmental instability, especially when posterior decompression of the canal and vertebral foramen is indicated. The use of this technique should be encouraged to be performed by spine surgeons. References - EGGER E., GOTTSAUNER-WOLF F., PALMER J., et al.: Effects of axial dynamization on bone healing. J. Trauma, 4: 85-9, HARMS J. and ROLINGER H.: A one-stage procedure in operative treatment of spondylolistheses: Dorsal traction-reposition and anterior fusion [in German]. Z. Orthop. Ihre. Grenzgeb., 0: 4-47, AGAZZI S., REVERDIN A., MAY D.: Posterior lumbar interbody fusion with cages: An independent review of 7 cases. J. Neurosurg. (Spine ), 9: 86-9, BAKER J.K., REARDON P.R., REARDON M.J. and HEGGENESS M.H.: Vascular injury in anterior lumbar surgery. Spine, 8: 7-0, BENZEL E.C.: Ventral exposures of the lumbar spine, in Benzel E.C. (ed): Surgical Exposure of the Spine: An Extensile Approach. Park Ridge, AANS, pp 99-6, FRASER R.D.: Interbody, posterior, and combined lumbar fusions. Spine 0 (Suppl 4): 67S-77S, GROB D., SCHEIER H.J., DVORAK J., SIEGRIST H., RUBELI M. and JOLLER R.: Circumferential fusion of the lumbar and lumbosacral spine. Arch. Orthop. Trauma. Surg., : 0-5, CHRISTENSEN F.B. and BUNGER C.E.: Retrograde ejaculation after retroperitoneal lower lumbar interbody fusion. Int. Orthop., : 76-80, HALVORSON T.L., KELLEY L.A., THOMAS K.A., WHITECLOUD T.S. III and COOK S.D.: Effects of bone mineral density on pedicle screw fixation. Spine, 9: 45-40, PROLO D.J., OKLUND S.A. and BUTCHER M.: Toward uniformity in evaluating results of lumbar spine operations. A paradigm applied to posterior lumbar interbody fusions. Spine, : , BRANTIGAN J.W.: Carbon fiber I/F Cage system for interbody vertebral Fusion. In Haid RW, Mclaughlin MR, Fessler RG. Lumbar Interbody Fusion Techniques. Cages, Dowels, and Grafts. Quality Medical publishing, Inc. ST. Louis, Missori. Ch., 9: pp 47-7, LOWE T., TAHERNIA A.D.: Unilateral transforaminal posterior interbody fusion. Scoliosis Research Society Annual Meeting, San. Diego, CA, HUMPHREYS S.C., HODGES S.D., PATWARDHAN A.G., ECK J.C., MURPHY R.B. and COVINGTON L.A.: Comparison of posterior and transforaminal approaches to lumbar interbody fusion. Spine, 6: , TRIBUS C.B.: Circumferential fusion techniques. In Resnick D.K., Haid R.W. (eds). The surgical management of low back pain. American Association of Neurological Surgeon, 7-, 00.