Anterior Cervical Discectomy and Fusion Using a Stand-Alone Polyetheretherketone Cage Packed with Local Autobone : Assessment of Bone Fusion and Subsidence

OBJECTIVE: It remains debatable whether cervical spine fusion cages should be filled with any kind of bone or bone substitute. Cortical and subcortical bone from the anterior and posterior osteophytes of the segment could be used to fill the cage. The purposes of the present study are to evaluate the clinical outcomes and radiological outcomes including bone fusion and subsidence that occurred after anterior cervical discectomy and fusion using a stand-alone cage packed with local autobone graft. METHODS: Thirty-one patients who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage packed with local autobone graft from July 2009 to december 2011 were enrolled in this study. Bone fusion was assessed by cervical plain radiographs and computed tomographic scan. Nonunion was evaluated according to the absence of bony bridge on computed tomographic scan. Subsidence was defined as a > or =2 mm decrease of the interbody height at the final follow-up compared to that measured at the immediate postoperative period. RESULTS: Subsidence was observed in 7 patients (22.6%). Of 7 patients with subsidence greater 2 mm, nonunion was developed in 3. Three patients with subsidence greater 2 mm were related with endplate damage during intraoperative endplate preparation. Solid bone fusion was achieved in 28 out of 31 patients (90.3%). CONCLUSION: With proper patient selection and careful endplate preparation, anterior cervical discectomy and fusion (ACDF) using a stand-alone PEEK cage packed with local autobone graft could be a good alternative to the standard ACDF techniques with plating.

Posterior Lumbar Interbody Fusion and Unilateral Posterolateral Fusion with Local Bone and Single Cage: Comparison with Posterolateral Lumbar Fusion and Autologous Iliac Bone / 대한정형외과학회잡지

PURPOSE: To evaluate the effectiveness of posterior lumbar interbody fusion (PLIF) using a single cage and unilateral posterolateral fusion (PLF) with local bone, and to compare the clinical and radiological results with those of posterolateral lumbar fusion (PLF) with autologous iliac bone. MATERIALS AND METHODS: Fifty patients with single segment degenerative lumbar disease were treated with spinal fusion. Twenty six patients, who underwent PLIF with single cage and local bone without autologous iliac bone, were classfied as the "cage group". The other 24 patients, who underwent PLF using autologous iliac bone, were classified as the "PLF group". The fusion rate, lumbar lordortic angle, segmental angle, and intervertebral disc height were compared in the radiograph between the two groups. The clinical outcomes were evaluated by the Oswestry Disability Index. Statistical analysis was performed using a T-test and Chi-Square test. RESULTS: The bony fusion rate was 80.8% in the cage group and 83.3% in the PLF group. The intervertebral disc height was restored better in the cage group, but there was no statistical difference between the two groups (p=0.10). Average intraoperative blood loss was similar in the two groups (565 ml in the cage group vs 567 ml in the PLF group). The average operation time was longer in the cage group but the difference was not significant (146.7 min vs 134 min). In the PLF group, 22 patients experienced pain at the iliac graft donor site in the early postoperative period that persisted for more than 6 months in 5 patients. CONCLUSION: PLIF using a single cage and local bone for single segment degenerative lumbar disease produced satisfactory bony fusion with none of the donor site morbidity at the iliac bone.

Comparison of Monosegment Instrumented Posterior Lumbar Interbody Fusion with and without a Metal Cage in Degenerative Spine / 대한정형외과학회잡지

PURPOSE: To compare the radiological and clinical results of a local bone graft with those of a single cage in monosegement instrumented posterior lumbar interbody fusion (PLIF) for a spinal stenosis or low-grade spondylolisthesis at the L4-5 level. MATERIALS AND METHODS: Eighteen patients underwent PLIF using a local bone block and a chip bone without a cage (no-cage group) and 24 patients underwent PLIF using a local bone graft with a single non-threaded metal cage (cage group). All the patients were followed up for a minimum of 2 years. The disc space height, disc lordosis, bone union and clinical results according to Lin's criteria of both groups were reviewed and compared retrospectively. RESULTS: The disc space heights of the no-cage and cage groups increased by 27% and 44% at the immediate postoperative and 12% and 27% at the latest follow-up, respectively. The cage group showed significantly better restoration of the disc space height (p0.05). Clinical satisfactory results were obtained in 72% of the no-cage group and 84% of the cage group without a significant difference (p>0.05). CONCLUSION: Both groups had a significant loss of restored disc space height 3 months after surgery. PLIF using a cage showed better restoration of the disc space height but there was significant loss of disc lordosis during the follow-up. A cage with sufficient height is recommended for restoring the disc space as well as preventing a loss of disc lordosis.

The Effect of Demineralized Bone Matrix as a Graft Enhancer in Posterior Lumbar Interbody Fusion Using Cage and Local Bone Chips / 대한척추외과학회지

STUDY DESIGN: A randomized, controlled study OBJECTIVES: We wanted to investigate whether osteogenesis can be enhanced when a small amount of demineralized bone matrix (1 cc/segment) is mixed with local bone chips. SUMMARY OF LITERATURE REVIEW: Demineralized bone matrix (DBM) has been used for spinal arthrodesis. However, there are only a few reports about its use as a composite graft with local bone chips for posterior lumbar interbody fusion MATERIALS AND METHODS: Degenerative spine patients, who would normally be treated by decompression and posterior lumbar interbody fusion with using a pedicle screw system and one cage, were randomly, prospectively selected for whether they would be treated with using local bone chips mixed with 1cc of DBM (Group I: 15 patients and 19 segments) or local bone chips (Group II: 12 patients and 13 segments) for graft material. The sampling bias was investigated for gender, age, endocrine diseases, previous operation, habits (alcohol drinking, smoking), steroid medication, bone mineral density and the amount of local bone. The amount of bone formation was measured at 6 months after operation. On the sagittal and coronal reconstruction CT images, the bone formation outside of the cage was measured, and this was interpreted in a "blinded"fashion by 2 independent doctors who did not take part in the operations. RESULTS: There was no sampling bias between the 2 groups except for age (Group I= 65.3+/-7.1, Group II=58.9+/-6.0, p=0.010). The ratio of local bone chips and DBM was 5.98:1 in Group I. There was moderate concurrence between the 2 interpreters (kappa coefficiency= 0.494, p<0.001 for the sagittal plain images and kappa co-efficiency=0.467, p<0.001 for the coronal plain images) and Group I showed significantly more bone formation (p=0.003). CONCLUSION: DBM that is mixed with local bone chips, even with small amount, enhanced bone formation in the posterior lumbar interbody fusion. This is regarded to act as a graft enhancer to increase the fusion rate, even when using local bone chips for graft material, for the cases that show unfavorable conditions for fusion or for the cases that are prone to loosening of hardware.

Posterior Lumbar Interbody Fusion with Cage and Local Bone Graft in Spondylolisthesis: Unilateral-caged versus Bilateral-caged / 대한척추외과학회지

STUDY DESIGN: Retrospective, controlled study OBJECTIVE: To compare one and two-caged posterior lumbar interbody fusion (PLIF) with local bone grafting for spondylolisthesis. SUMMARY OF LITERATURE REVIEW: Even though there are many reports on PLIF using cages and local bone grafting, Studies comparing one and two-caged PLIFs are rare. MATERIALS AND METHODS: Sixty-three patients who underwent pedicle screw fixated PLIF using cages and local bone grafts were followed for more than 1 year. Twenty-five patients had one cage (group I), and 38 patients had two cages (group II). Sampling error, disc height, sagittal Cobb angle, coronal Cobb angle, fusion rate, Oswestry disability index (ODI), operation time, blood loss, and neurologic complications were assessed. RESULTS: There was no sampling error between the two groups, except with regard to diagnosis: degenerative spondylolisthesis, 15 cases in group I and 9 cases in group II; spondylolytic spondylolisthesis, 10 cases in group I and 29 cases in group II (p=0.004). Fusion rates were 87.5% and 88.2% for groups I and II, respectively (p=1.000). More disc height loss occurred in group I (0.6 mm) than in group II (0.0 mm) (p=0.041). Over-3mm-disc height-losses were noted more frequently in group I (20%) than in group II (2.6%) (p=0.022). ODI improved from 28.1 to 12.3 (72.1% improvement) in group I and from 29.2 to 12.7 (79.3% improvement) in group II. There were no significant differences in operation time, amount of blood loss, or neurologic complications between the two groups. CONCLUSION: Unilateral one-caged PLIF with local bone grafting and posterior instrumentation was no different from bilateral two-caged PLIF with regard to fusion rates or radiologic or clinical results. The statistically significant differences in disc height seemed to be clinically insignificant. Disc height loss of greater than 3 mm was much more common in group I, with one-caged PLIF.

Unilateral Transforaminal Lumbar Interbody Fusion in Spondylolisthesis: Comparison with Conventional Posterior Lumbar Interbody Fusion Through Bilateral Approach / 대한척추외과학회지

STUDY DESIGN: Retrospective controlled study. OBJECTIVES: The aim of this study was to determine if unilateral TLIF is comparable to conventional PLIF with regard to radiologic and clinical outcomes, and to examine the viability of local bone for bone grafting in lumbar interbody fusion. SUMMARY OF LITERATURE REVIEW: TLIF, a modified form of PLIF, is a new spinal fusion technique that avoids the typical complications of PLIF. MATERIALS AND METHODS: We analyzed 32 cases of single-level TLIF or PLIF in patients with degenerative or isthmic spondylolisthesis, who were followed for more than 1 year. The patients in group 1 underwent TLIF, and the patients in group 2 underwent PLIF. The fusion rate, changes in disc height, and degree of anterolisthesis in the fused segment were analyzed radiologically. The clinical results were evaluated using the Oswestry Disability Index and visual analog scale. We also analyzed operative time, blood loss, and complications in both groups. RESULTS: Radiologically and clinically, there were no significant differences between the two groups in terms of fusion rate, changes in disc height, or degree of anterolisthesis in the fused segment. The mean operative time was 200 minutes in group 1 and 240 minutes in group 2. The mean blood loss was 854 ml in group 1 and 1102 ml in group 2(p>0.05). CONCLUSIONS: TLIF is a potentially useful alternative to conventional PLIF in patients with degenerative or isthmic spondylolisthesis. Additionally, local bone may be a viable source of bone grafts for single-level TLIF and PLIF.

Posterior Lumbar Interbody Fusion Using Titanium Cages and Morselized Local Bone Autograft / 대한척추외과학회지

STUDY DESIGN: A retrospective study to evaluate the results of posterior lumbar interbody fusion (PLIF) using titanium cages filled with morselized local bone. OBJECTIVE: To verify the clinical and radiological results of the PLIF procedure using rectangular titanium cages filled with morselized local bone. SUMMARY AND LITERATURE REVIEW: Stabilization of the spine can be achieved by interbody arthrodesis through the posterior approach. However many significant problems including bone graft collapse, resorption, nonunion, and iliac donor site morbidity caused by the classic PLIF procedure need to be solved. The use of local bone and a titanium cage might be a solution. MATERIALS AND METHOD: Fifty-nine patients(average age at surgery, 51.3 years), who underwent surgery for degenerated low back disease, were enrolled in this study. The average follow-up duration was 19.9 months. The radiological fusion status, intervertebral disc heights, visual analogue scales, clinical outcomes were evaluated. RESULTS: Forty-three (73%) patients were classified as complete-union, 16 (27%) patients as probable-union, and no patients were classified as non-union. The average intervertebral disc height increased by 3.7 mm at immediate postoperatively, and the average subsidence was 1.1 mm at the final follow-up. The average visual analogue scale decreased from 5.5 to 1.4 for back pain and from 6.6 to 0.8 for radicular pain. Nineteen (32%) and 28 (48%) patients were classified as excellent and good, respectively, according to clinical outcome assessment by Kim and Kim criteria. The complications encountered were a dural tear in 8 patients, partial root injury in 1, and upper adjacent segment instability during follow-up in 2. CONCLUSION: PLIF using titanium cages filled with morselized local bone has the advantages of maintaining an intervertebral disc height, immediate stability, and the avoidance of donor site morbidity. However, longer-term results are needed, because the follow-up period of this study was relatively short

Local Bone versus Autogenous Iliac Bone Graft for Posterolateral Lumbar Fusion in the Same Patient / 대한척추외과학회지

STUDY DESIGN: A prospective study. OBJECTIVES: To determine the usefulness of local bone obtained from laminectomy and decortication as graft bone instead of autogenous iliac bone in posterolateral lumbar spinal fusion. MATERIALS AND METHODS: Thirty-one patients underwent posterolateral lumbar spinal fusion with pedicle screw instrumentation. Local bone was inserted in the right side of intertransverse space and autogenous iliac bone was in the left side. We compared fusion rate in the radiographs at postoperative 6 week, 3 month, 6 month and 1 year. RESULTS: Radiographic fusion grading of local bone was 20 cases of grade 1, 8 cases of grade 2, 2 cases of grade 3 and 1 case of grade 4. Fusion grading of autogenous iliac bone was 24 cases of grade 1, 4 cases of grade 2 and 3 cases of grade 3. Bone fusion was complete after 9.1 months in local bone and 7.2 months in autogenous iliac bone. No significant differences was found between the two groups. CONCLUSION: The local bone in posterolateral lumbar fusion is appropriate for satisfactory fusion instead of autogenous iliac bone if the amount of local bone is sufficient and decortication of the fusion bed is proper.

Comparison Between Allograft Mixed with Local Bone and Autograft in Posterolateral Lumbar Fusion / 대한척추외과학회지

STUDY DESIGN: A prospective study. OBJECTIVES: To determine the usefulness of allograft and compare the result of allograft mixed with local bone and autograft in posterolateral lumbar fusion. SUMMARY OF LITERATURE REVIEW: Allograft is used for the purpose of spinal fusion, especially in the scoliosis surgery. In some studies allograft is not recommended in posterior lumbar spinal fusion alone. MATERIALS AND METHODS: Fifteen patients underwent one level posterolateral lumbar fusion using freeze-dried allograft mixed with local bone. We compared them with twenty four patients using autogenous iliac bone graft mixed with local bone about radiographic fusion grading, duration of fusion and clinical outcomes. RESULTS: Radiographic fusion grading of allograft was 7 cases of grade 1, 5 cases of grade 2, 3 cases of grade 3, and grading of autograft was 21 cases of grade 1, 2 cases of grade 2, 1 cases of grade 3. Bone fusion was complete after 11.1 months in allograft and 6.7 months in autograft. Clinically, there were 4 excellent, 9 good, 2 fair cases in allograft and 10 excellent, 11 good, 3 fair cases in autograft. CONCLUSIONS: Allograft was inferior to autograft in posterolateral lumbar fusion because allograft mixed with local bone reduced radiographic fusion grading and prolonged duration of bone fusion.