Radiologic Comparison of the Sacroiliac Joint Degeneration Following Lumbar or Lumbosacral Fusion / 대한척추외과학회지

STUDY DESIGN: Retrospective study.OBJECTIVES: To compare the degeneration of sacroiliac joint (SIJ) following lumbar or lumbosacral fusion.SUMMARY OF LITERATURE REVIEW: The SIJ is adjacent to lumbosacral junction and its degeneration can be the potential cause of pain. However, the study addressing SIJ degeneration following lumbar or lumbosacral fusion is very limited.MATERIALS AND METHODS: From June 2002 to June 2012, 98 patients who underwent posterior decompression and posterolateral fusion were included in this study. The study group was divided into 2 groups according to the range of fusion. Group A had fusion to L5 and included 34 patients. Group B had fusion to S1 and included 64 patients. We evaluated the five years postoperative radiologic and clinical outcomes retrospectively.RESULTS: There was no statistically significant difference of bilateral preoperative subchondral sclerosis and osteophytes of the SIJ between group A and group B. However, group B revealed statistically significant subchondral sclerosis and osteophyte formation of the SIJ than group A on every radiographs after postoperative 1 year. In group B, the number of fusion segments and age were statistically positively correlated with the degeneration of the SIJ.CONCLUSIONS: Degeneration of the SIJ revealed more rapid and more severe progression in lumbosacral fusion group than in lumbar fusion group. The number of fusion segments and age were positively correlated with the degeneration of the SIJ in lumbosacral fusion group. Therefore, these facts should be taken into account when performing spinal fusion.

Lumbar fusion with collagen type I and polyvinylpyrrolidone in combination with autograft. An experimental study in New Zealand rabbits / Colágena tipo I y polivinilpirrolidona en combinación con autoinjerto para artrodesis lumbar. Estudio experimental en conejos de Nueva Zelanda

Abstract: Introduction: Multiple strategies have been developed looking for upgrading the consolidation rate of spine arthrodesis with autolog bone graft, but no evidence exists that adhesion with Collagen type 1 and polyvinylpyrrolidone (FibroquelMR) have application on this field. Objective: Determine if collagen type 1 + Polyvinylpyrrolidone are effective as bone enhancer in posterolateral arthrodesis on rabbits. Method: Posterolateral arthrodesis in 15 New Zealand rabbits on level L5-L6 using autolog bone graft in left side (control group) and autolog bone graft + 1 ml FibroquelMR (study group) in right side of arthrodesis. Euthanasia and block resection of lumbar segment eight weeks post surgery. Radiographic analysis, manual exploration and light microscopy of fussed segments. Results: Radiographic consolidation was observed in 80% in control group and 95% in study group, interleaved trabecular pattern with bone continuity and normal characteristics in 12 left sides and 14 right sides. Conclusion: Collagen type 1 and polyvinylpyrrolidone use is likely to have positive effect in bone consolidation process, therefore it can be recommended to use it as a bone enhancer.

Resumen: Introducción: Existen diversas estrategias para aumentar la tasa de consolidación de la artrodesis de columna en presencia de injerto óseo autólogo, sin aún comprobar si la adhesión de Colágena tipo I y polivinilpirrolidona (FibroquelMR) tienen aplicaciones en este campo. Objetivo: Determinar la efectividad de la colágena tipo I con polivinilpirrolidona como potenciador óseo en artrodesis posterolateral de conejos. Métodos: Artrodesis posterolateral en 15 conejos de Nueva Zelanda L5-L6 colocando injerto autólogo del lado izquierdo (Control) e injerto autólogo + 1 ml FibroquelMR (Estudio) en el lado derecho de la artrodesis. Eutanasia con resección en bloque del segmento lumbar a las ocho semanas del postoperatorio. Análisis radiográfico, palpación manual y por microscopia de luz de los segmentos fusionados. Resultados: Se observó consolidación radiográfica en 80% en grupo control y 93% en el estudio, continuidad ósea con patrón trabecular intercalado y hueso de características normales en 12 del lado izquierdo y 14 en el lado derecho. Conclusiones: La utilización de Colágena tipo I y polivinilpirrolidona puede tener efectos positivos en el proceso de consolidación ósea por lo que se puede recomendar su utilización como reforzador óseo.

Clinical Outcomes of Percutaneous Endoscopic Lumbar Discectomy for Adjacent Lumbar Disc Herniation after Lumbar Posterolateral Fusion by Radiologic Evaluations

STUDY DESIGN: A retrospective study. OBJECTIVE: To analyze the effectiveness of percutaneous endoscopic lumbar discectomy (PELD) for adjacent lumbar disc herniation through radiologic evaluations. SUMMARY OF LITERATURE REVIEW: PELD minimizes posterior structural damage, allowing rapid rehabilitation. SUBJECTS AND METHODS: This study was conducted on 45 patients who were followed up for 1 year after PELD for adjacent lumbar disc herniation from March 2014 to February 2016. The modified Macnab criteria, the modified Suezawa and Schreiber score (MSS score), and visual analogue scales for the back (VAS-B) and legs (VAS-L) were evaluated. The disc height ratio and segmental angulation change were compared before posterolateral fusion and before PELD. Moreover, spinal stenosis was confirmed on magnetic resonance imaging (MRI) before PELD. RESULTS: Based on the modified Macnab criteria, 53.3% patients received an evaluation of at least “good,” and the mean MSS score improved from 4.77 to 6.99 at 1 year after the operation. The mean VAS-B score decreased from 7.02 to 4.67, and the mean VAS-L score decreased from 8.15 to 4.24 at 1 year after the operation. The mean disc height ratio was 87.1%, and the mean segmental angulation change was 6.5°, with a greater change in the “fair” or “poor” group, and the rate of spinal stenosis on MRI was also higher in the “fair” or “poor” group. CONCLUSION: The clinical outcomes of PELD, which is accompanied by degenerative changes on simple radiographic images such as disc space narrowing and increased segmental angulation or spinal stenosis on MRI, may not be satisfactory. Therefore, decisions regarding surgery should be made carefully in such cases.

Outcomes of Revision Surgery Following Instrumented Posterolateral Fusion in Degenerative Lumbar Spinal Stenosis: A Comparative Analysis between Pseudarthrosis and Adjacent Segment Disease

STUDY DESIGN: Retrospective study. PURPOSE: We examined the clinical and radiological outcomes of patients who received revision surgery for pseudarthrosis or adjacent segment disease (ASD) following decompression and instrumented posterolateral fusion (PLF). OVERVIEW OF LITERATURE: At present, information regarding the outcomes of revision surgery for complications such as pseudarthrosis and ASD following instrumented PLF is limited. METHODS: This study examined 60 patients who received PLF for degenerative lumbar spinal stenosis and subsequently developed pseudarthrosis or ASD leading to revision surgery. Subjects were divided into a group of 21 patients who received revision surgery for pseudarthrosis (Group P) and a group of 39 patients who received revision surgery for ASD (Group A). Clinical outcomes were evaluated using the visual analogue scales for back pain (VAS-BP) and leg pain (VAS-LP), the Korean Oswestry disability index (K-ODI), and each patient's subjective satisfaction. Radiological outcomes were evaluated from the extent of bone union, and complications in the two groups were compared. RESULTS: VAS-LP at final follow-up was not statistically different between the two groups (p =0.353), although VAS-BP and K-ODI at final follow-up were significantly worse in Group P than in Group A (all p <0.05), and only 52% of the patients in Group P felt that their overall well-being had improved following revision surgery. Fusion rates after the first revision surgery were 71% (15/21) in Group P and 95% (37/39) in Group A (p =0.018). The rate of reoperation was significantly higher in Group P (29%) than in Group A (5%) (p =0.021) due to complications. CONCLUSIONS: Clinical and radiological outcomes were worse in patients who had received revision surgery for pseudarthrosis than in those who had revision surgery for ASD. Elderly patients should be carefully advised of the risks and benefits before planning revision surgery for pseudarthrosis.

Comparison of Clinical and Radiological Results of Posterolateral Fusion and Posterior Lumbar Interbody Fusion in the Treatment of L4 Degenerative Lumbar Spondylolisthesis

STUDY DESIGN: Multicenter analysis of two groups of patients surgically treated for degenerative L4 unstable spondylolisthesis. PURPOSE: To compare the clinical and radiographic outcomes of posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) for degenerative L4 unstable spondylolisthesis. OVERVIEW OF LITERATURE: Surgery for lumbar degenerative spondylolisthesis is widely performed. However, few reports have compared the outcome of PLF to that of PLIF for degenerative L4 unstable spondylolisthesis. METHODS: Patients with L4 unstable spondylolisthesis with Meyerding grade II or more, slip of >10degrees or >4 mm upon maximum flexion and extension bending, and posterior opening of >5 degree upon flexion bending were studied. Patients were treated from January 2008 to January 2010. Patients who underwent PLF (n=12) and PLIF (n=19) were followed-up for >2 years. Radiographic findings and clinical outcomes evaluated by the Japanese Orthopaedic Association (JOA) score were compared between the two groups. Radiographic evaluation included slip angle, translation, slip angle and translation during maximum flexion and extension bending, intervertebral disc height, lumbar lordotic angle, and fusion rate. RESULTS: JOA scores of the PLF group before surgery and at final follow-up were 12.3+/-4.8 and 24.1+/-3.7, respectively; those of the PLIF group were 14.7+/-4.8 and 24.2+/-7.8, respectively, with no significant difference between the two groups. Correction of slip estimated from postoperative slip angle, translation, and maintenance of intervertebral disc height in the PLIF group was significantly (p<0.05) better than those in the PLF group. However, there was no significant difference in lumbar lordotic angle, slip angle and translation angle upon maximum flexion, or extension bending. Fusion rates of the PLIF and PLF groups had no significant difference. CONCLUSIONS: The L4-L5 level posterior instrumented fusion for unstable spondylolisthesis using both PLF and PLIF could ameliorate clinical symptoms when local stability is achieved.

The Effect of Teriparatide in Women with Osteoporosis after Lumbar Posterolateral Fusion or Posterior Lumbar Interbody Fusion

STUDY DESIGN: Retrospective study. OBJECTIVES: To investigate radiologic and clinical outcomes of teriparatide in women with osteoporosis after instrumented lumbar posterolateral fusion (PLF) or posterior lumbar interbody fusion (PLIF). SUMMARY OF LITERATURE REVIEW: Teriparatide accelerated lumbar posterolateral fusion in women with postmenopausal osteoporosis. MATERIALS AND METHODS: Eighty-six women older than 65 years old with osteoporosis underwent PLF or PLIF with bone graft between Februar, 2011 ato May, 2012 pPatients were divided into four group: teriparatide group with local bone (A-1: 13 patients;, teriparatide group with composite bone (A-2: 27 patients; non-teriparatide group with local bone (B-1: 14 patients; and non-teriparatide group with composite bone (B-2: 32 patients). At 3, 6, and 12 months postoperatively, the Oswestry Disability Index (ODI), visual analog scale (VAS), fusion rate, and period of bone union were evaluated. RESULTS: VAS and ODI improved after surgery in all groups, but no significant differences were notell among the groupses Further, there was no significant difference among the groups for agef fusion level, and fusiops(p>0.05). Fusion rate was 94.44% in the A-1 group, 92.59% in the A-2 group, 79.17% in the B-1 group, and 76.92% in the B-2 group. Average period of bone union was 3.25 months, 3.65 months, 5.67 months, anand 5.65 months respectively. Fusion rate and average bone union time made no significant differeneen among the groups divided by graft materials (p>0.05). However, those in the teriparatide group were significantly superior to those in the non-teriparatide group (p<0.05). CONCLUSIONS: In women with osteoporosis after PLF or PLIF with bonegraft, teriparatide showed superiority in the rate of fusion and the period of bone union.

Union Rates of Autologous Bone Marrow, Local Autobone and Biphasic Calcium Phosphate Mixed Graft in Lumbar Posterolateral Fusion

STUDY DESIGN: A retrospective study. OBJECTIVES: We examined union rates and clinical outcomes to evaluate the efficacy of using autologous bone marrow along with a local autobone and biphasic calcium phosphate mixed graft with posterolateral fusion in spinal stenosis and spondylolisthesis. SUMMARY OF LITERATURE REVIEW: In lumbar posterolateral fusion, union rates of biphasic calcium phosphate and local autobone mixed graft are low compared to union rates of autogenous iliac bone graft. MATERIALS AND METHODS: Among the patients who had lumbar posterolateral fusion with autologous bone marrow along with local autobone and biphasic calcium phosphate mixed graft between February 2013 and January 2014, we analyzed 40 patients who were available for at least one year of follow-up. There were 22 cases with spinal stenosis and 18 cases with spondylolisthesis. Bone fusion was determined along with the fusion rates based on Lenke's criteria (citation). All patients were evaluated postoperatively at one year, using 3D CT. and the clinical outcomes were assessed using Kim's method (citation). RESULTS: In spinal stenosis, bone union was observed in 19 cases out of 22 (86.4%), and in case of spondylolisthesis, bone union was observed in 16 cases out of 18 (88.9%). In spinal stenosis, the clinical outcomes were: 2 excellent, 16 good, 3 fair, and 1 poor; in other words 18 cases (81.8%) displayed good or excellent outcomes. In spondylolisthesis, 2 excellent, 12 good, 4 fair and 0 poor; in other words, 14 cases (77.8%) showed good or superior outcomes. CONCLUSIONS: Posterolateral fusion using autologous bone marrow along with a local autobone and biphasic calcium phosphate mixed graft showed similar bone fusion rates to using autogenous iliac bone graft. Therefore, this method could serve as an alternative to using autogenous iliac bone graft in posterior lumbar fusion.

Clinical application of short-segment nail-stick system combined with annular fusion in lumbar spondylolisthesis / 重庆医学

Objective To investigate the clinical effect of the bone graft fusion of the posterior lumbar interbody fusion (PLIF) combined with posterolateral fusion(PLF) in treating lumbar spondylolisthesis .Methods 63 cases of lumbar spondylolisthesis were performed the posterior unilateral or bilateral vertebral plate resection ,nerve root canal decompression ,clearing the slippage space , reduction ,fixation short-segment vertebral pedicle nail-stick system for reduction and fixation ,bone graft fusion with the interverte-bral space Cage and posterior-lateral bone graft fusion ,vertebral pedicle isthmus cracking was performed the clearance and bone graft fusion(PLIF combined with PLF ) .The JOA scores ,lumbar lordosis ,segment lordosis ,intervertebral space height ,slippage rate and complications were recorded before operation ,in postoperative 1 week ,6 ,12 months .Results All cases had no serious complications .The JOA scores were increased to some different degrees from the beginning of postoperative 1 week ,with the reha-bilitation time extension ,the JOA scores were gradually increased ,the improvement rate of the postoperative JOA score averaged 85 .00% .The lumbar lordosis ,segment lordosis ,intervertebral space height and slippage rate after operation were significantly im-proved compared with before operation ,the fusion failure rate was 4 .76% .Conclusion The bone graft fusion of PLIF combined with PLF is one of ideal methods to treat lumbar spondylolisthesis .

Biphasic Calcium Phosphate and Local Autobone Mixed Graft in Lumbar Posterolateral Fusion

STUDY DESIGN: Retroprospective study. OBJECTIVES: To evaluate the efficacy of biphasic calcium phosphate and local autobone mixed graft in cases of spinal stenosis and spondylolisthesis in posterolateral fusion by examining radiologic union rates and clinical outcomes. SUMMARY OF LITERATURE REVIEW: It can be a practical alternative to the use of tricalcium phosphate in hydroxyapatite as a graft aid since using hydroxyapatite mixture in lumbar spine fusion has been reported to lead to a high rate of bone union. MATERIALS AND METHODS: From July 2011 to February 2013, we followed up 107 patients who had lumbar posterolateral fusion using biphasic calcium phosphate composed of HA/TCP (60:40) and local autobone mixed graft. Of these patients, 64 had spinal stenosis and 43 had spondylolisthesis. The bone fusion rate was determined using Lenke's criteria and clinical outcomes were evaluated using Kim's method. RESULTS: In spinal stenosis, bone union was presented in 53 patients (of 64; 82.8%) and in spondylolisthesis, 35 patients (of 43; 81.4%). In spinal stenosis, the clinical outcomes resulted in 20 excellent, 34 good, 9 fair and 1 poor. (84.4%, excellent or good) In spondylolisthesis, the clinical outcomes resulted in 10 excellent, 25 good, 7 fair and 1 poor. (81.4%, excellent or good). CONCLUSION: Posterolateral fusion using biphasic calcium phosphate and local autobone mixed graft showed high rates of bone union and acceptable clinical outcomes, and is considered a satisfactory bone graft aid.

Clinical and Radiological Comparison of Posterolateral Fusion and Posterior Interbody Fusion Techniques for Multilevel Lumbar Spinal Stabilization In Manual Workers

STUDY DESIGN: Eighty-four patients who had been treated for degenerative spinal diseases between January 2006 and June 2009 were reviewed retrospectively. PURPOSE: We aimed to compare the clinical and radiologic findings of manual workers who underwent posterolateral fusion (PLF) or posterior interbody fusion (PLIF) involving fusion of 3 or more levels of the spine. OVERVIEW OF LITERATURE: Previous studies have concluded that there is no significant difference between the clinical outcome of PLF and PLIF techniques. METHODS: After standard decompression, 42 patients underwent PLF and the other 42 patients underwent PLIF. Radiologic findings, Oswestry disability index (ODI) scores, and visual analogue scale (VAS) scores were assessed preoperatively and at 6-month intervals postoperatively and return to work times/rates were assessed for 48 months. RESULTS: Patients who underwent PLF had significantly shorter surgical time and less blood loss. According to the 48-month clinical results, ODI and VAS scores were reduced significantly in the two groups, but the PLIF group showed better results than the PLF group at the last follow-up. Return to work rate was 63% in the PLF group and 87% in the PLIF group. Union rates were found to be 81% and 89%, respectively, after 24 months (p=0.154). CONCLUSIONS: PLIF is a preferable technique with respect to stability and correction, but the result does not depend on only the fusion rates. Discectomy and fusion mass localization should be considered for achieving clinical success with the fusion technique. Before performing PLIF, the association of the long operative time and high blood loss with mortality and morbidity should be taken into consideration, particularly in the elderly and disabled patients.

Delayed Retroperitoneal Hemorrhage due to Lumbar Artery Pseudoaneurysm after Lumbar Posterolateral Fusion

A 55-year-old female patient presented with lower back pain and neurogenic intermittent claudication and underwent L3-L4 posterolateral fusion. To prepare the bone fusion bed, the transverse process of L3 and L4 was decorticated with a drill. On the 9th post-operative day, the patient complained of a sudden onset of severe abdominal pain and distension. Abdominal computed tomography revealed retroperitoneal hematoma in the right psoas muscle and iatrogenic right L3 transverse process fracture. Lumbar spinal angiography showed the delayed hematoma due to rupture of the 2nd lumbar artery pseudoaneurysm and coil embolization was done at the ruptured lumbar artery pseudoaneusyrm. Since then, the patient's postoperative progress proceeded normally with recovery of the hemodynamic parameters.

Correlation of Adjacent Segmental Disease with Tilt Angles of the Upper and Lower Instrumented Vertebra in the Degenerative Lumbar Scoliosis

STUDY DESIGN: Retrospective study. OBJECTIVES: To evaluate the correlation of adjacent segmental disease with tilt angles of the upper and lower instrumented vertebra after instrumented posterolateral fusion for degenerative lumbar scoliosis. SUMMARY OF LITERATURE REVIEW: There has been no study of radiologic measurement and decision of fusion level using the angle of pedicle screws inserted for treatment of degenerative lumbar scoliosis. MATERIALS AND METHODS: From 2004 to 2008, 74 patients that underwent decompression and posterolateral fusion for degenerative lumbar scoliosis were included in this study. In all cases, instrumentation and posterolateral fusion were both performed. The sex ratio was 31:43, the mean age was 68.7 years and the mean follow up duration was 37.4 months. The angle between each upper end plate of the upper vertebral body and lower end plate of the lower vertebral body of the fusion, and the line parallel to the axis of the sagittal line of vertebrae was each defined as UIV-a and LIV-b. The correlation of development of adjacent segment disease and UIV-a, and LIV-b angle was investigated. RESULTS: Sum of the absolute value of UIV-a and LIV-b had a statistically significant positive correlation with that of adjacent segment disease. Also, UIV-a alone, had a statistically positive correlation with the development of proximal adjacent segment disease. CONCLUSIONS: Since it is proven that adjacent segment disease has positive correlation with the sum of the absolute value of UIV-a and LIV-b, the extent of fusion should be adjusted to make the line parallel to the line perpendicular to the sagittal surface.

The Comparison of Clinical and Radiologic Results Classified by Translation Type and Fusion Method in the Isthmic Spondylolisthesis

STUDY DESIGN: A retrospective study. OBJECTIVES: To examine the radiologic and clinical results of patients classified as excessive translation and excessive angulation, treated by posterolateral fusion only, or posterolateral fusion with posterior lumbar interbody fusion in isthmic spondylolisthesis. SUMMARY OF LITERATURE REVIEW: Isthmic spondylolisthesis is usually treated by PLF only or PLF with PLIF. But it is not reported the clinical and radiologic results classified by translation type. MATERIALS AND METHODS: Patients who had received surgery for spondylolisthesis between January 2005 to January 2010, there were 56 for whom follow-up observations were possible for 2 years. According to the fusion methods and preoperative flexion-extension simple radiograph, we classified as excessive translation and excessive angulation by segmental instability and as PLF and PLIF by surgical methods. We examine the clinical results(Visual Analogue Scale, Oswestry Distability Index, operation time, blood loss, complication rate) and the radiologic results(reduction rate of slippage, change of segmental angle, reduction ratio of disc height, bone union). RESULTS: In radiologic results, excessive angulation(group II) did not show significant difference from excessive translation(group I) in terms of reduction rate of slippage, change of segmental angle, reduction ratio of disc height, bone union. But we found excessive translation-PLIF(group I-B) was better than excessive translation-PLF(group I-A) and excessive angulation-PLIF(group II-B) was better than excessive angulation-PLF(II-A) in terms of reduction ratio of disc height(P<0.05). In clinical results, both sides group did not show significant difference in operation time, blood loss, complication rate. CONCLUSIONS: In spondylolisthesis patients, excessive translation group(I) and excessive angulation group(II) did not show significant difference in radiologic results and clinical results. But both sides group showed the PLF with PLIF was better than the PLF only in terms of reduction ratio of disc height.

Union Rates of Local Autobone and beta-Tricalcium Phosphate Mixed Graft in Lumbar Posterolateral Fusion

STUDY DESIGN: A retroprospective study. OBJECTIVES: We used a local autobone and beta-tricalcium phosphate mixed graft with posterolateral fusion in spinal stenosis and spondylolisthesis and evaluated union rates to verify the efficacy. SUMMARY OF LITERATURE REVIEW: Several reports have shown high union rates of posterolateral fusion using beta-tricalcium phosphate. However, in Korea, only one study reported a low union rate. MATERIALS AND METHODS: Forty-two patients who underwent lumbar posterolateral fusion with a local autobone and beta-tricalcium phosphate mixed graft from September 2010 to July 2011 were followed up. There were 32 cases with spinal stenosis and 10 cases with spondylolisthesis. Bone fusion was determined along with the fusion rates based on Lenke's criteria. Clinical outcomes were determined using Kim's method. RESULTS: In spinal stenosis, bone union was presented in 19 cases(59.4%) out of 32 cases and in spondylolisthesis, bone union was presented in 7 (70.0%) out of 10. In spinal stenosis, 12 cases showed excellent outcome, 16 good, 3 fair and 1 poor, 27 cases(87.5%) were superior to the good. In spondylolisthesis, 2 cases showed excellent outcome, 5 good, 3 fair and 0 poor, 8 cases(70.0%) were superior to the good. CONCLUSIONS: Posterolateral fusion using a local autobone and beta-tricalcium phosphate mixed graft showed lower bone fusion rates. We need further studies to enhance the fusion rate when using local autobone and beta-tricalcium phosphate mixed grafts.

Comparison of Posterior Fixation Alone and Supplementation with Posterolateral Fusion in Thoracolumbar Burst Fractures

OBJECTIVE: We compared the radiological and clinical outcomes between patients who underwent posterior fixation alone and supplemented with fusion following the onset of thoracolumbar burst fractures. In addition, we also evaluated the necessity of posterolateral fusion for patients treated with posterior pedicle screw fixation. METHODS: From January 2007 to December 2009, 46 consecutive patients with thoracolumbar burst fracture were included in this study. On the basis of posterolateral fusion, we divided our patients into the non-fusion group and the fusion group. The radiological assessment was performed according to the Cobb's method, and results were obtained at immediately, 3, 6, 12 months after surgery. The clinical outcomes were evaluated using the modified Mcnab criteria at the final follow-up. RESULTS: The demographic data and the mean follow-up period were similar between the two groups. Patients of both groups achieved satisfactory clinical outcomes. The mean loss of kyphosis correction showed that patients of both groups experienced loss of correction with no respect to whether they underwent the posterolateral fusion. There was no significant difference in the degree of loss of correction at any time points of the follow-up between the two groups. In addition, we also compared the effect of fixed levels (i.e., short versus long segment) on loss of correction between the two groups and there was no significant difference. There were no major complications postoperatively and during follow-up period. CONCLUSION: We suggest that posterolateral fusion may be unnecessary for patients with thoracolumbar burst fractures who underwent posterior pedicle screw fixation.

The Prognostic Factor of Posterolateral Fusion in Degenerative Spondylolisthesis

STUDY DESIGN: A retrospective analysis of the posterolateral fusion in degenerative spondylolisthesis. OBJECTIVES: Posterolateral fusion has been performed for patients about Meyerding grade1, 2 with degenerative spondylolisthesis in L4-5. We evaluated the prognostic factors of posterolateral fusion, alone for degenerative spondylolisthesis. SUMMARY OF LITERATURE REVIEW: It is reported that posterolateral fusion has almost equal postoperative clinical and radiographic results with the interbody or circumferential fusion for spondylolisthesis. However, there have been some unsatisfactory results after posterolateral fusion alone and the causes are yet unknown. MATERIAL AND METHODS: From January 2002 to July 2008, we analyzed postoperative clinical outcomes of 42 patients who were diagnosed with Meyerding 1 or 2 grade degenerative spondylolisthesis at L4-5. All the patients were classified into group I and group II, based on the clinical outcome evaluation method by Kirkaldy-Willis. Ten patients (Group I) were found to have poor or fair clinical outcomes, while 32 patients (Group II) were found to have excellent or good clinical outcomes. The mean duration of the follow up was 16.3 (12-23) months. We looked into postoperative body mass index and bone mass density, and found degenrative lumbar disc through preoperative MRI, retrospectively. We measured angular motion by dynamic radiographs and preoperative slip angle through a Taillard method. RESULTS: In group I, the average preoperative BMI was 25.7 (21.2~31.4) and the average T score of bone density was -3.0 (-1.9~-4.2). There was 1 case of Grade 3, 3 cases of Grade 4 and 6 cases of Grade 5 by preoperative Pfirmann classification. The average angular motion was 11.8 (9.1~14.2) and the average preoperative slip angle was 8.4 (6.9-9.6). In group II, the average preoperative BMI was 24.3 (20.72~28.1) and the average T score of bone density was -2.1 (-0.9~-3.1). There were 26 cases of Grade 3, 5 cases of Grade 4 and 1 case of Grade 5 by preoperative Pfirmann classification. The average angular motion was 8.8 (6.2~12.1) and the average preoperative slip angle was 6.2 (3.6-7.9). There were statistically significant differences between the two groups in BMI, stage of disc degeneration, preoperative angular motion, and slip angle. (p=0.04, 0.04, 0.05, 0.03, respectively) CONCLUSION: We concluded that posterolateral fusion has exhibited worse clinical results in cases of BMI less than -2.8, disc degeneration greater than grade 4, angular motion greater than 9.4 degrees, and slip angle greater than 7.1 degrees; as such, we need to consider other surgical methods.

Comparative Study of Posterior Lumbar Interbody Fusion with Posterolateral Fusion in Degenerative Lumbar Spinal Disorders

STUDY DESIGN: A retrospective study. OBJECTIVES: The authors found that problems such as axial pain, donor site pain, loss of reduction, loosening or failure of fixation materials occurred relatively frequently after posterolateral fusion. For this, we had views on the ideas that the problems could be improved by an operation that fused vertebral bodies. Furthermore, we performed posterior lumbar interbody fusion and wanted to know the results. SUMMARY OF LITERATURE REVIEW: We performed posterior lumbar inter-body fusion as an alternative, due to complications of autoiliac bone graft that has complications, such as donor site pain. MATERIALS AND METHODS: Sixty patients with single segment degenerative lumbar disease were treated with decompression, pedicle screws fixation, and spinal fusion. The patients were followed-up for more than 2 years. Thirty patients, who had undergone posterolateral fusion with autologous iliac bone graft, were classified as the "group 1". The second 30 patients, who underwent posterior lumbar interbody fusion with cage and local bone graft, were classified as the "group 2". The operation time, blood loss, fusion rate, lumbar lordotic angle, segmental angle were compared between the 2 groups. The clinical outcomes were evaluated by Kim's functional evaluation scale. RESULTS: The operation time was shorter in group 2 (142.74 minutes vs 171.64 minutes), there was a statistical difference between the 2 groups. Intraoperative blood loss was more in group 2 (563.40 vs 551.78 mL), but total blood loss, including postoperative drained blood was less in group 2. The bony fusion rate was 90% in group 1, 97% in group 2. For the lumbar lordotic angle, the last outcome was less than the preoperative value. There was no statistical difference between the 2 groups. The segmental angle in group 1, the last outcome was less than the preoperative value. The segmental angle in group 2 was maintained the value through pre-operation to post-operation. Clinical outcomes were satisfactory in group 1 (96.67%) & in group 2 (100%). In group 1, 7 patients experienced pain at the iliac graft donor site. In group 2, there were 2 cases of retroposition of the cage. CONCLUSIONS: In the posterior lumbar interbody fusion group, operation time was shorter, total blood loss was less than in the posterolateral fusion group. Restoration and maintenance of the segmental angle in sagittal and coronal radiographs showed better outcomes, axial pain and iliac donor site pain were less. It is the authors' position that posterior lumbar interbody fusion is an alternative operation to supplement the faults of posterolateral fusion.

The First Clinical Trial of Beta-Calcium Pyrophosphate as a Novel Bone Graft Extender in Instrumented Posterolateral Lumbar Fusion

BACKGROUND: Porous beta-calcium pyrophosphate (beta-CPP) was developed to improve the fusion success of posterolateral lumbar fusion (PLF). The possibility of accomplishing PLF using a mixture of porous beta-CPP and iliac bone was studied. This paper reports the radiologic results of PLF using the beta-CPP plus autograft for lumbar degenerative disease as a bone graft extender. METHODS: A prospective, case-matched, radiographic study evaluating the results of short segment lumbar fusion using a beta-CPP plus autograft was performed to compare the efficacy of beta-CPP plus autograft with that of an autograft alone for short segment lumbar fusion. Thirty one consecutive patients (46 levels) underwent posterolateral fusion with pedicle screw fixation and additional posterior lumbar interbody fusion. In all patients, 3 mL of beta-CPP plus 3 mL of autogenous bone graft was placed randomly in one side of a posterolateral gutter, and 6 mL of autogenous iliac bone graft was placed on the other. The fusion rates, volumes of fusion masses, and bone absorption percentage were evaluated postoperatively using simple radiographs and 3 dimensional computed tomography (3D-CT) scans. RESULTS: The control sides treated with an autograft showed significantly better Lenke scores than the study sides treated with beta-CPP at 3 and 6 months postoperatively, but there was no difference between the two sides at 12 months. The fusion rates (confirmed by 3D-CT) were 87.0% in the beta-CPP group and 89.1% in the autograft group, which were not significantly different. The fusion mass volumes and bone absorption percentage at 12 months postoperatively were 2.49 mL (58.4%) and 1.89 mL (69.5%) for the beta-CPP and autograft groups, respectively, and mean fusion mass volume was significantly higher in the beta-CPP group. CONCLUSIONS: beta-CPP combined with an autograft is as effective as autologous bone for grafting during instrumented posterolateral spinal fusion. These findings suggest that beta-CPP bone chips can be used as a novel bone graft extender for short-segment posterolateral spinal fusion.

Risk Factors of Nonunion Demanding Surgical Treatment after Lumbar Posterolateral Fusion

STUDY DESIGN: This is a retrospective study for radiographically and clinically assessing nonunion after lumbar spine fusion. OBJECTIVES: We wanted to analyze the risk factors for nonunion that requires surgical treatment after lumbar spine fusion SUMMARY OF THE LITERATURE REVIEW: A diagnosis of the nonunion after lumbar spine fusion was made by using only the only radiologic images. The incidence of nonunion has been underreported because there are many asymptomatic patients. MATERIALS AND METHODS: The plain X-ray films were evaluated for 1317 patients who could be followed up more than 1 year after lumbar fusion. Nonunion was diagnosed at 1 year after fusion by instability seen on the flexion-extension radiograph and the clinical findings like as sustained pain and local tenderness at the surgical site. The risk factors we reviewed included age, the number of levels fused, associated diseases, smoking, alcohol drinking, the initial diagnosis, a previous history of spinal operation, infection, a clear zone and malposition of pedicle screws and metal failure. The relations between nonunion and the factors mentioned above were analyzed. RESULTS: Thirty-nine patients were diagnosed as having nonunion underwent reoperation and all had surgically confirmed nonunion. Smoking, infection and a previous history of spine operation had a significant influence on nonunion (p < 0.05). Clear zones persisting more than 1 year and metal failure also had a significant influence on nonunion (p < 0.05). Age, the number of fused levels, the initial diagnosis and alcohol drinking were not shown to influence the rate of nonunion (p < 0.05). CONCLUSION: A through clinical and radiologic evaluation is essential to diagnose nonunion, and this should not be done according to the radiologic images only. Risk factors such as a previous history of spine operation, infection, smoking, the development of a clear zone and metal failure all showed a statistically significant influence on nonunion. Additionally, preoperative and postoperative evaluation of these parameters is needed to achieve bone union.

Treatment Outcome of Lower Lumbar Fracture with Neurological Deficit

STUDY DESIGN: A retrospective study. OBJECTIVES: To evaluate the clinical results of surgical treatment for a lower lumbar fracture with a neurological deficit. SUMMARY OF LITERATURE REVIEW: There are several methods for treating lower lumbar fractures with neurological deficits but no definitive guidelines have been established. MATERIALS AND METHODS: From 2000 to 2008, this study reviewed 26 patients who had undergone surgery to treat a lower lumbar fracture with a neurological deficit and could be followed up for more than 12 months. The changes in the kyphotic angle, changes in the vertebral body height, compromise ratio of the spinal canal, recovery of neurological deficit, and clinical results were evaluated. RESULTS: There were 15, 7 and 4 cases with a third, fourth and fifth lumbar fracture, respectively. There are 19, 2 and 5 cases of an unstable bursting fracture, chance fracture and translational injury, respectively. The compromise ratio of the spinal canal improved from 67.2+/-9.4% to 16.4+/-4.6%, and the changes in the kyphotic angle improved from 14.5+/-3.2degrees to 7.6+/-2.4degrees postoperatively and 9.7+/-4.3degrees at the last follow-up. The changes in the vertebral body height improved from 41.3+/-8.4% to 23.4+/-6.3% and the bone union rate was 92.3%. The neurological deficit recovered with 1.27degrees according to the Frankel classification and good functional results were obtained in 84.6% of cases. CONCLUSIONS: Recovery of the neurological deficit and good clinical results were obtained with the recovery of the kyphotic angle and bone union with posterior decompression and instrumented posterolateral fusion in lower lumbar fractures with a neurological deficit.