Clinical Efficacy of a Stand-Alone, Threaded-Titanium Fusion Cage for Single-Level Degenerative Lumbar Spinal Disorders / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical and radiologic efficacy of posterior lumbar interbody fusion (PLIF) using a threaded fusion cage (TFC) alone with autogenous iliac corticocancellous bone graft for single-level degenerative lumbar spinal disorders. MATERIALS AND METHODS: Thirty-eight consecutive patients receiving PLIF with TFC alone were evaluated with at least three years of follow-up. Clinical outcome and satisfaction were assessed using Ragab's measurements. Radiological outcomes were analyzed in terms of lumbar lordosis, segmental lordosis, disc height, and fusion rates. RESULTS: Disc height was 6.18+/-2.54 mm, 11.71+/-1.60 mm and 9.94+/-1.94 mm on average for preoperative, postoperative, and final follow-up, respectively. Lumbar lordosis was 27.46+/-11.47degrees, 31.41+/-8.89degrees on average for preoperative and at final follow-up, respectively. Segmental lordosis was 11.51+/-9.35degrees preoperatively, and 10.86+/-7.49degrees at final follow-up. Satisfactory clinical outcome were obtained in 89.2% of patients with successful bone fusion in 73.0% of patients. CONCLUSION: Stand alone TFC is an effective treatment modality in maintenance of disc height and lumbar lordosis, with satisfactory long term clinical outcomes in the treatment of single-level degenerative lumbar spinal disorders.

Posterior Lumbar Interbody Fusion with Threaded Fusion Cage: Long-term Follow-up Results

OBJECTIVES: Of all fusion techniques in the lumbar spines, PLIF has the best theoretical opportunity in achieving spinal fusion by way of load sharing effect of the anterior column but it is taken to be a technically demanding procedure and frequent problems have been reported. Threaded Fusion Cage(TFC) has been used as a substitute for autologous bone grafts during posterior lumbar interbody fusion in degenerative lumbar diseases since 1992. The purpose of this study is to evaluate the long-term efficacy of TFC in achieving a spinal fusion and the clinical outcome. METHODS: Total 597 patients underwent PLIF with TFC using laminectomy bone chips as bone graft during the last 7 years. Among them, 351 patients could be followed-up for more than 3 years and their clinical and radiographic data were reviewed retrospectively. Total 497 segments of PLIF with TFC were done in those 351 patients, their mean follow-up period were 59.8+/-9.1 months. RESULTS: The clinical success according to Prolos scale were achieved in 83.2% of the patients. When observed according to the disease entities, however multiple spondylotic stenosis patients showed significantly less favorable outcome(p<0.05). In the radiologic evaluation, bony fusion was achieved in 92.0% but when observed according to the disease entities, the fusion rate was significantly lower in the spondylolytic spondylolisthesis patients(p<0.05). CONCLUSION: The PLIF with TFC has been found to be an effective and safe procedure for lumbar spine fusion, demonstrating a high fusion rate and clinical success with rare complications. In addition, using the laminectomy bone chips as the bone graft in the TFC seemed to provide successful bony fusion without further invasive and painful procedure to obtain iliac bone graft.

Long Term Follow up Results of Threaded Fusion Cage(T.F.C.) in Surgical Treatment of Spondylolisthesis

The goal of operation in spondylolisthesis is improving radiculopathy and relieving lower back pain preventing further progression of the slip, through decompression of neural elements and fusion of spinal pseudoarthrosis, respectively. The author performed the posterior lumbar interbody fusion technique using a Threaded Fusion Cage(T.F.C.) for 41 patients as the surgical treatment for mild spondylolisthesis. All patients enrolled in the study were implanted with a T.F.C. at a single unstable level. We have investigated the outcome results for at least one year(mean 25.8 months). Of these patients 95% have shown solid fusions. Using the Prolo scale for economic and functional rating, the combined results of excellent, good score is 51%, but clinically symptomatic improvement is 66%. Therefore, posterior lumbar interbody fusion using T.F.C. was useful in treatment of mild degree spondylolisthesis.

Clinical, Radiological Analysis of Threaded Fusion Cage(TFC) in Surgical Treatment of Spondylolisthesis

The indications for surgical treatment of spondylolisthesis are as follows:pain unrelieved by conservative treatment. Persistent neurologic signs. Progression of the slip or slip greater than 50 per cent. Postural deformity or walking difficulty due to tight hamstring muscles. The goal of operation for spondylolisthesis is to relieve radiculopathy and low back pain, and to prevent further progression of the slip through decompression of neural elements and fusion for pseudoarthrosis. The authors performed the posterior lumbar interbody fusion using Threaded Fusion Cage(TFC) on 23 patients with spondylolisthesis. All patients have been followed for 3 to 12 months. We then studied the clinical and radiological outcomes of these patients and verified the relationship between clinical outcomes and radiological findings. Summaries of the results are as followings. 1) Successful bone fusion was achieved in 20 out of 23 cases(87%). 2) Neurological signs were improved in 20 out of 23 cases(87%). 3) The majority of cases which demonstrated radiologic bone fusion also showed clinical improvement. Posterior lumbar interbody fusion using TFC was useful in the treatment of mild degree spondylolisthesis.

Posterior Lumbar Interbody Fusion with Threaded Fusion Cage(TFC)

Of all fusion techniques in the lumbar spines, posterior lumbar interbody fusion(PLIF) has the best theoretical opportunity to achieve fusion by way of compression loading of the bone graft between the well vascularized vertebral bodies. Even though the rationale for the PLIF is quite reasonable, it has been a very technically demanding procedure and frequent problems have been reported which include protrusion of bone grafts, settling of the interspace and pseudoarthrosis. A new deice, Threaded Fusion Cage(TFC) seems to be an ideal solution for the various technical problems which hindered greater success of PLIF in the past. Maintenance of stability and absence of loss of disc height are assured due to the threaded metal tube concept. We have operated PLIF with TFC in 60 patients since last December. The preoperative diagnoses were 27 degenerative disc diseases, 25 degenerative spondylolisthesis, 7 spondyloysis & listhesis and 1 FBSS. Our initial experience with the clinical results show that the most of the patient have marked improvement of low back pain and reduction is possible in almost cases of the spondylolisthesis. Long term follow up is needed as to the future of the threaded cage, but it would appear that once they have been in a stable position and fusion with the patients' own bone has occurred. In our opinion, the use of TFC in the future will be widely spread and represents an ideal method for the treatment of chronic low back pain and spinal instability.

Posterior Lumbar Interbody Fusion with Threaded Fusion Cage(TFC)

Of all fusion techniques in the lumbar spines, posterior lumbar interbody fusion(PLIF) has the best theoretical opportunity to achieve fusion by way of compression loading of the bone graft between the well vascularized vertebral bodies. Even though the rationale for the PLIF is quite reasonable, it has been a very technically demanding procedure and frequent problems have been reported which include protrusion of bone grafts, settling of the interspace and pseudoarthrosis. A new deice, Threaded Fusion Cage(TFC) seems to be an ideal solution for the various technical problems which hindered greater success of PLIF in the past. Maintenance of stability and absence of loss of disc height are assured due to the threaded metal tube concept. We have operated PLIF with TFC in 60 patients since last December. The preoperative diagnoses were 27 degenerative disc diseases, 25 degenerative spondylolisthesis, 7 spondyloysis & listhesis and 1 FBSS. Our initial experience with the clinical results show that the most of the patient have marked improvement of low back pain and reduction is possible in almost cases of the spondylolisthesis. Long term follow up is needed as to the future of the threaded cage, but it would appear that once they have been in a stable position and fusion with the patients' own bone has occurred. In our opinion, the use of TFC in the future will be widely spread and represents an ideal method for the treatment of chronic low back pain and spinal instability.