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Background and Objectives: This study is a retrospective analysis aimed at understanding the incidence and risk factors of proximal junctional kyphosis (PJK) following long-instrumented spinal fusion from L1 to the sacrum in patients with mild to moderate sagittal imbalance. Materials and Methods: It recruited consecutive patients undergoing instrumented fusion from L1 to the sacrum for degenerative lumbar disease between June 2006 and November 2019 in a single institution. The patients' preoperative clinical data, muscle status at T12-L1 on magnetic resonance images, and sagittal spinopelvic parameters were analyzed. Univariate analysis was used to compare clinical and radiographic data between PJK and non-PJK patients. Logistic regression analysis was used to investigate the independent risk factors for PJK. Results: A total of 56 patients were included in this study. The mean age at surgery was 67.3 years and mean follow-up period was 37.3 months. In total, 10 were male and 46 were female. PJK developed in 23 (41.1%) out of 56; of these patients, 20 (87.0%) developed PJK within 1 year postoperatively. In the univariate analysis between PJK and non-PJK patients, the PJK group showed more frequent osteoporosis, lower body mass index, smaller cross-sectional area (CSA) and more fat infiltration (FI) in erector spinae muscle at T12-L1 and larger preoperative TLK and PT with statistical significance ( p < 0.05). In the logistic regression analysis, severe (>50%) FI in erector spinae muscle (OR = 43.60, CI 4.10-463.06, R 2 N = 0.730, p = 0.002) and osteoporosis (OR = 20.49, CI 1.58-264.99, R 2 N = 0.730, p = 0.021) were statistically significant. Conclusions: Preexisting severe (>50%) fat infiltration in the erector spinae muscle and osteoporosis were independent risk factors associated with PJK following instrumented fusion from L1 to the sacrum, but age was not a risk factor.

During lateral lumbar interbody fusion (LLIF), unintended intraoperative endplate injury (IEPI) can occur and thereafter lead cage subsidence. The aim of this study was to investigate the incidence of IEPI during LLIF, and its predisposing factors. A retrospective review was conducted on consecutive patients (n = 186; mean age, 70.0 ± 7.6 years) who underwent LLIF at 372 levels. Patient's demographic and surgical data were compared between patients with and without IEPI. Also, the radiographic data of each level were compared between intact and IEPI segments. IEPI was identified at 76 levels (20.4%) in 65 patients. The incidences of IEPI at every 100 consecutive segments were not different. When 372 segments were analyzed independently, sagittal disc angle (DA) in the extended position (4.3° ± 3.6° at IEPI segments vs. 6.4° ± 4.0° at intact segments), the difference between sagittal DA in the extended position and cage angle (- 2.2° ± 4.0° vs. 0.0° ± 3.9°), and the difference between preoperative disc height and cage height (- 5.4 mm ± 2.4 mm vs. - 4.7 mm ± 2.0 mm) were different significantly. Also, endplate sclerosis was more common at intact segments than IEPI segments (33.2% vs. 17.3%). Multivariate analysis showed that male sex (odds ratio [OR] 0.160; 95% confidence interval [CI] 0.036-0.704), endplate sclerosis (OR 3.307; 95% CI 1.450-8.480), and sagittal DA in the extended position (OR 0.674; 95% CI 0.541-0.840) were significant associated factors for IEPI. IEPI was correlated not with surgeon's experience, but with patient factors, such as sex, preoperative disc angle, and endplate sclerosis. Careful surgical procedures should be employed for patients with these predisposing factors., (© 2021. The Author(s).)

Objective: Recently, new patient-reported outcome measures (PROMs) of the spine were designed to overcome the limitations of previous spinal PROMs and to consider the whole spine as a single kinetic functional unit. Owing to the significance of spine-hip-knee and global body balance, the spine and lower extremities cannot be considered separately. However, no reports have evaluated lower-extremity functional outcome using PROMs after lumbar spine surgery. The authors aimed to elucidate changes in hip and knee PROMs after lumbar interbody fusion and to evaluate the sagittal spinopelvic radiographic parameters that were most strongly correlated with lower-extremity PROMs., Methods: In 2018, the authors consecutively evaluated patients who underwent lumbar interbody fusion surgery with at most three levels. Preoperative and 1-year postoperative clinical and radiographic data were assessed. Spinal functional outcomes were measured with the Oswestry Disability Index (ODI), visual analog scale (VAS) for pain, and Scoliosis Research Society-22r (SRS-22r) questionnaire. Lower-extremity functional outcomes were evaluated with the Harris Hip Score (HHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Linear regression was used to evaluate the relationship between spinal and lower-extremity PROMs and spinopelvic radiographic parameters., Results: The authors enrolled 67 patients, with a mean age of 66.4 years. The average number of surgical levels was 1.7. All assessed PROMs improved significantly after surgery (p < 0.001 for ODI, p < 0.001 for VAS, p = 0.017 for SRS-22r, p = 0.042 for HHS, and p = 0.033 for WOMAC). Spinopelvic parameters, including lumbar lordosis (LL), pelvic tilt (PT), C7 sagittal vertical axis, and sagittal radiographic parameters of hip and knee, significantly improved after surgery. On linear regression analysis, HHS and WOMAC correlated with LL and PT, respectively (β = 0.554 and p = 0.043 for correlation of HHS with LL; β = 1.573 and p = 0.021 for correlation of WOMAC with PT)., Conclusions: The current study demonstrated that lumbar fusion surgery may induce postoperative improvements in lower-extremity functional and radiological outcomes. However, among radiographic parameters, changes in LL and PT were the most strongly associated with lower-extremity PROMs.

Background: More caudal osteotomy is believed to lead to greater sagittal correction; however, the osteotomy level and whether or not to use iliac screw fixation (ISF) are topics of on-going debate. The aim of this study was to compare clinical and radiographic outcomes after revisional lumbar pedicle subtraction osteotomy (PSO) for fixed sagittal imbalance (FSI) according to the osteotomy level and ISF., Methods: All consecutive patients who underwent revisional PSO (at L3 or L4) for FSI in a single institute from July 2006 to January 2014 were investigated retrospectively. Thirty-eight patients with at least 2-year follow-up were finally included. Clinical outcomes including the visual analogue scale (VAS) and Oswestry Disability Index (ODI) were investigated. Radiographic spinopelvic parameters were analyzed according to the level of PSO, the degree of correction, and the use of ISF., Results: The mean number of fused segments after PSO was 6.6 ± 1.8. Sagittal vertical axis (SVA) was restored after the surgery (12, 2.5, and 5.2 cm at preoperative, postoperative, and the last follow-up, respectively). PSO was performed at L3 in 16 patients and at L4 in 22 patients. The osteotomy level was not associated with any changes of spinopelvic parameters (pelvic tilt [PT] or lumbar lordosis) or sagittal alignment (T1-pelvic angle [TPA] or SVA). However, better TPA restoration was achieved with more osteotomy resection angle (P = 0.031). ISF group showed significant improvement in postoperative pelvic orientation (PT and ratio of PT to pelvic incidence) which was maintained until the last follow-up., Conclusions: Although postoperative sagittal alignment was different in FSI patients according to the osteotomy level, pelvic orientation improved in ISF group. Also, the degree of correction showed significant associations with sagittal alignment. When performing revisional PSO for FSI, spine surgeon should carefully consider how to correct rather than where to do the osteotomy, and the role of ISF., Competing Interests: Declaration of Competing Interest All authors declare no conflict of interest., (Copyright © 2020 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Objective: We investigated the characteristics and revision rate of junctional failure after surgical correction for thoracolumbar kyphosis in patients with ankylosing spondylitis., Methods: A total of 230 patients had undergone surgical correction for thoracolumbar kyphosis from 2010 to 2019. The state of ankylosis between the uppermost instrumented vertebra (UIV) and UIV+1 and between the lowermost instrumented vertebra (LIV) and LIV-1 was analyzed using a modified Stoke ankylosing spondylitis spine score. Proximal junctional failure (PJF) and distal junctional failure (DJF) were defined as any type of symptomatic junctional failure., Results: Of the 230 patients, 23 (10.0%) had developed junctional failure. Of these 23 patients, 16 had had partial ankylosis and 7 had had complete ankylosis. PJF had developed in 10 patients and DJF in 13. The most common type of junctional failure was a junctional fracture, which developed in 12 patients. PJF had developed by UIV fracture in 4 patients, UIV+1 fracture in 1 patient, and UIV+2 in 1 patient. DJF had developed by LIV fracture in 6 patients, metallic failure in 5, and progression of DJF in 2 patients. The average time to the development of PJF and DJF was 13 months and 12.4 months, respectively. All 10 patients with PJF and 7 of 13 patients with DJF (53.8%) had required reoperation. Of the 12 patients with junctional fracture, 11 (91.7%) had undergone reoperation., Conclusions: Of the 23 patients with junctional failure, 16 had had immature ossification of the anterior longitudinal ligament. Therefore, to prevent junctional failure, the state of ankylosis seems to be important for selecting the fusion level after osteotomy. Once junctional failure has developed, however, reoperation should be considered owing to the stress concentration at the UIV or LIV., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Study Design: A retrospective study., Objective: The aim of this study was to investigate proximal junctional kyphosis (PJK) after lumbosacral long fusion according to preoperative Roussouly and lumbar degenerative kyphosis (LDK) types., Summary of Background Data: Although previous studies have suggested some risk factors for PJK, the effects of preoperative grade of sagittal imbalance and paraspinal muscles degeneration on PJK remain unclear., Methods: Eighty-seven patients who had undergone lumbosacral fusion more than five levels with available clinical and radiological data were enrolled. The presence of PJK defined as sagittal Cobb angle ≥20° between the uppermost instrumented vertebra (UIV) and two supra-adjacent vertebrae at postoperative 2-year radiographs was recorded. Its occurrence was compared according to preoperative Roussouly and LDK types (Takemistu type) and the degree of paraspinal muscle degeneration at the upper level of UIV. Other sagittal radiographic parameters were also measured., Results: In this series, 28 patients (group I, 32.2%) showed radiological PJK, whereas 59 patients did not show radiological PJK (non-PJK patients, group II, 67.8%) at postoperative 2 years. PJK presented more prevalence in type III and type IV of LDK types (26/27, 96.3%). However, Roussouly types did not show any significant difference in PJK prevalence. In radiological parameters, a larger preoperative SVA (P = 0.018) and PI-LL (P = 0.015) were associated with PJK. Also, smaller quantity and lower quality of paraspinal muscles at T12-L1 level showed significant (P < 0.001) relationship with PJK. On multivariate logistic regression, higher LDK type (odds ratio [OR]: 2.11, 95% confidence interval [CI]: 1.24-3.56), smaller quantity (OR: 1.03, 95% CI: 1.00-1.07), and higher degree of paraspinal muscle degeneration (OR: 1.46, 95% CI: 0.92-2.31) were independent predictors of postoperative PJK., Conclusion: Although various factors are related to PJK following long segment fusion, preoperative conditions such as LDK types and degree of paraspinal muscle degeneration might be related to the development of PJK.Level of Evidence: 3., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

The purpose of this study was to report the characteristics of SIFs after ILSF and discuss its management focusing on pelvic deformation. We retrospectively reviewed all consecutive patients who underwent ILSF for degenerative disc diseases during the period between 2000 and 2017 and were diagnosed as SIF at our institute. The clinical and radiographic data were reviewed on their medical charts. Treatment outcomes for SIF were also investigated. Eight patients (all females) were included in this study. Mean age at SIF diagnosis was 72 years, and the mean follow-up period was 3.8 years (range 1-7 years). SIF developed average 7.5 years (range 1 month-17 years) after the index ILSF. Fracture patterns were unilateral vertical in four, bilateral vertical in three, and horizontal in 1 patient. Unlike patients with unilateral vertical SIF, patients with bilateral vertical or horizontal SIF showed a marked increase of pelvic incidence (PI) by mean 17.0°±5.0° and sagittal vertical axis (SVA) by mean 4.5 ± 2.2 cm, compared to the respective values before the onset of abrupt pain. All patients with unilateral vertical SIF were treated favorably by conservative management, however sacropelvic fixation was inevitable in patients with bilateral vertical or horizontal SIF. Bilateral vertical or horizontal SIF showed marked changes on sagittal radiographic parameters including PI and SVA. Although unilateral vertical SIF has benign courses that responded well to conservative management, bilateral vertical or horizontal SIF is likely to need surgical treatment. Treatment plan should be determined depending on fracture pattern and pelvic deformation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Study Design: Retrospective case-control study., Objective: To investigate the effects of postoperative sagittal alignment on radiographic adjacent segment degeneration (ASD) after lumbar fusion surgery., Summary of Background Data: ASD is one of inherent problems with fusion surgery. Many confounding factors are related to the development of ASD. Recently, sagittal alignment has been emphasized for its significance on ASD., Methods: Seventy-three patients who underwent four-level lumbar fusion surgery (L2-S1) were divided into two groups according to postoperative sagittal alignment (pelvic incidence-lumbar lordosis [PI-LL] ≥ or <9°): 44 patients (matched group, including 10 patients who underwent pedicle subtraction osteotomy [PSO] at L4) and 29 patients (mismatched group). The general demographics, radiographic parameters, and clinical outcomes were recorded. Preoperative disc degeneration at L1-2 was evaluated by Pfirrmann grade and Kellgren-Lawrence (K-L) grade. Disc degeneration at L1-2 was evaluated by the K-L grade on 2-year postoperative X-rays., Results: The incidence of radiographic ASD (11 [25%] vs. 16 patients [55%], P = 0.02) and Oswestry Disability Index (ODI) scores (36.9 ± 19.9 vs. 49.4 ± 20.7, P = 0.015) at postoperative 2 years were significantly higher in the mismatched group. There were no significant differences in other demographic and radiographic parameters between the two groups. On subgroup analysis between 10 PSO patients and the mismatched group, the mismatched group showed a higher incidence of radiographic ASD (16 [55%] vs. 1 patient [10%], P = 0.041) and worse ODI scores (49.7 ± 20.5 vs. 39.0 ± 20.7, P = 0.040). Preoperative Pfirrmann grade at L1-2 (odds ratio [OR] = 4.191, 95% confidence interval [CI]: 1.754-10.013, P = 0.001) and postoperative PI-LL mismatch (OR = 4.890, 95% CI: 1.550-15.427, P = 0.007) showed significant relationships with the development of radiographic ASD at postoperative 2 years., Conclusion: The restoration of optimal sagittal alignment, even with PSO, may provide a protective effect on the development of radiographic ASD, although the preoperative disc degeneration grade was a risk factor for radiographic ASD., Level of Evidence: 3.

Background: Decompressive laminectomy alone for degenerative lumbar scoliosis (DLS) is not recommended because it can lead to further instability. However, it is uncertain whether instability at the decompressed segments is directly affected by laminectomy or the natural progression of DLS. The purpose of this study was to evaluate the surgical outcome of decompressive laminectomy alone for DLS with spinal stenosis and to determine whether the procedure leads to post-laminectomy instability (PLI)., Methods: We retrospectively reviewed 60 patients with DLS. They were divided into 2 groups according to PLI criteria: stable group and PLI group. The PLI group was subdivided into 2 groups based on the level of PLI: the first group that showed PLI at the index laminectomy level (PLI-I) and the second group that showed PLI at another level other than the laminectomy level (PLI-NI). Radiological evaluation was performed to determine factors associated with the progression of DLS. Pain and disability outcomes were assessed., Results: There were 34 patients (56.7%) in the stable group and 26 patients (43.3%) in the PLI group. Twelve patients (20.0%) underwent revision surgery. Eleven patients (18.3%) showed PLI at the index segments (PLI-I group), and 15 patients (25%) showed PLI at the adjacent or cephalad segments, not related to the laminectomy site (PLI-NI group). Four patients underwent revision surgery in the stable group and 8 in the PLI group. Survivorship analyses revealed that the predicted survivorship of DLS was 90.0% at 12 months and 86.4% at 24 months after laminectomy., Conclusions: The development of PLI was not always related to laminectomy at the index level. However, PLI developed more rapidly at the index level, compared to the natural progression of the scoliotic curve at the adjacent segments., Competing Interests: CONFLICT OF INTEREST: No potential conflict of interest relevant to this article was reported., (Copyright © 2020 by The Korean Orthopaedic Association.)

Study Design: This was a retrospective comparative study., Objective: The main objective of this article was to evaluate the clinical and radiologic efficacies of minimally invasive lateral lumbar interbody fusion (LLIF) for clinical adjacent segment pathology (ASP)., Summary of Background Data: Minimally invasive techniques have been increasingly applied for spinal surgery. No report has compared LLIF with conventional posterior lumbar interbody fusion for clinical ASP., Methods: Forty patients undergoing LLIF with posterior fusion (hybrid surgery) were compared with 40 patients undergoing conventional posterior lumbar interbody fusion (posterior surgery). The radiologic outcomes including indirect decompression in hybrid surgery group, and clinical outcomes such as the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) were assessed. Postoperative major complications and reoperations were also compared between the 2 groups., Results: Correction of coronal Cobb's angle and segmental lordosis in the hybrid surgery were significantly greater postoperatively (2.8 vs. 0.9 degrees, P=0.012; 7.4 vs. 2.5 degrees, P=0.009) and at the last follow-up (2.4 vs. 0.5 degrees, P=0.026; 4.8 vs. 0.8 degrees, P=0.016) compared with posterior surgery. As regards indirect decompression of the LLIF, significant increases in thecal sac (83.4 vs. 113.8 mm) and foraminal height (17.8 vs. 20.9 mm) were noted on postoperative magnetic resonance imaging. Although postoperative back VAS (4.1 vs. 5.6, P=0.011) and ODI (48.9% vs. 59.6%, P=0.007) were significantly better in hybrid surgery, clinical outcomes at the last follow-up were similar. Moreover, intraoperative endplate fractures developed in 17.7% and lower leg symptoms occurred in 30.0% of patients undergoing hybrid surgery., Conclusions: Hybrid surgery for clinical ASP has advantages of segmental coronal and sagittal correction, and indirect decompression compared with conventional posterior surgery. However, LLIF-related complications such as endplate fracture and lower leg symptoms also developed. LLIF should be performed considering advantages and approach-related complications for the clinical ASP.

Case: A 73-year-old man with instrumented fusion of L3-4-5 underwent the removal of previous pedicle screws and posterior instrumented fusion of L1-2-3. The solid dorsal fusion mass of L3-5 was identified intraoperatively and preoperatively. At 3 years after the second surgery, he presented with abrupt radiating pain in the left leg. Plain radiographs showed a collapse of the intervertebral disc space, and magnetic resonance imaging showed disc herniation of L3-4., Conclusions: Disc herniation even in solid fused segments may occur. Removal of pedicle screws and cranial extension of interbody fusion may increase the intradiscal stress associated with physiologic cantilever motion of the disc.

Study Design: This was a randomized clinical trial., Objective: To compare the efficacy and safety of nonsteroidal anti-inflammatory drug and opioid for acute pain management after lumbar decompressive surgery., Summary of Background Data: Multimodal analgesia is associated with synergistic effects while reducing opioid-related adverse effects. However, there is no consensus on the ideal multimodal analgesic regimen. We assumed that each agent in various multimodal regimens under different conditions may have different effects., Materials and Methods: This prospective randomized clinical trial recruited adult patients who underwent single-level lumbar decompressive surgery. Patients were randomized to receive our postoperative analgesic regimen including either nonsteroidal anti-inflammatory drug (celecoxib) or opioid (extended-release oxycodone) from postoperative day 3 to 14. The Visual Analog Scale (VAS) and Oswestry Back Pain Disability Index (ODI) were used to evaluate effectiveness preoperatively and on postoperative days 2, 3, 7, and 14, and at 6 months. Drug-related adverse effects were also recorded., Results: One hundred patients were enrolled and 93 patients (46 patients with celecoxib vs. 47 patients with oxycodone) were randomized. No differences were observed in patient demographics and preoperative VAS and ODI between the 2 groups. VAS and ODI were not different at all postoperative time points. However, subanalysis according to sex and age, revealed significant differences in efficacy: celecoxib was effective in female individuals and oxycodone was effective in male individuals on postoperative days 7 and 14; oxycodone was effective in patients aged above 65 years on postoperative days 7 and 14. Although nausea/vomiting and constipation were more common in the oxycodone group than in the celecoxib group, other adverse effects were not different., Conclusions: In patients who underwent single-level lumbar decompressive surgery, treatment with celecoxib and oxycodone for postoperative pain management showed no significant differences in efficacy. However, subanalysis showed that each drug was effective in different ages and sex groups., Level of Evidence: Level II.

Study Design: A retrospective comparative cohort study., Objective: To investigate the causes of jack-knife posture (JKP) without proximal junctional kyphosis (PJK) and to compare the causes of PJK and JKP without PJK., Summary of Background Data: PJK causing stooping posture could be inevitable after long instrumented lumbar fusion for degenerative sagittal imbalance. However, few studies have addressed JKP without PJK, which is a different type of sagittal malalignment., Methods: Ninety-four adult patients who underwent long instrumented lumbar fusion for degenerative sagittal imbalance were divided into three groups depending on the presence of a postoperative sagittal deformity: JKP, PJK, or none. JKP was defined as a sagittal vertical axis of at least 8 cm anterior to the posterosuperior corner of S1 upper endplate without PJK. PJK was defined as a proximal kyphotic angle ≥10° and at least 10° greater than the preoperative measurement., Results: Seventeen patients (18.1%) showed JKP, and 39 patients (41.5%) showed PJK. The mean age at the surgery of JKP and PJK patients was 70.0 and 65.5 years, respectively (p = .05). JKP developed more frequently if the preoperative pelvic tilt was <25° or the sagittal vertical axis was >8 cm (p = .048, 0.004, respectively). PJK developed more frequently if the preoperative pelvic tilt was >25°, surgically corrected lumbar lordosis was >30°, or the lumbar lordosis to thoracic kyphosis angle was <0° (p = .002, .010, .031, respectively). JKP was more likely to develop in patients without sacropelvic fixation (p = .042), although they had a more degenerative L5-S1 segment (p = .010)., Conclusions: Postoperative sagittal deformity can be classified into two types: JKP and PJK. JKP is caused mainly by hip and back extensor muscle weakness even though the cause of postoperative sagittal decompensation could be multifactorial. However, PJK developed mainly due to spinopelvic malalignment. Therefore, hip and back extensor weakness, which is age-dependent, may explain why older patients experienced more postoperative sagittal deformity., Level of Evidence: Level IV., (Copyright © 2018 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Rationale: Traumatic bilateral facet dislocation in the lumbar (L) spine has rarely been reported. All reported cases were presented with acute facet dislocation. However, we present the first case of delayed bilateral facet dislocation at L4-5., Patient Concerns: A 34-year-old woman presented with back pain after a head-on collision. The patient was treated conservatively for 3 months with rigid orthosis and activity restriction. Even after this conservative treatment, she continued to suffer from persistent back pain that radiated down her left leg and a progressively kyphotic posture., Diagnoses: Initial imaging studies revealed a fracture of the left L5 superior articular process with a posterior ligament complex (PLC) injury. Subsequent radiographs showed the locked facet dislocation with kyphotic changes., Interventions: The patient underwent surgical reduction and fusion, and the operative findings revealed the L4-5 bilateral facet dislocation and rupture of the PLC at the index level., Outcomes: After surgical reduction and fusion at L4-5 by posterior interbody fusion, we achieved a satisfactory clinical outcome., Lessons: Injury of the PLC in the lower lumbar region deserves careful attention for the development of sequelae. The anatomic transition from lordosis to kyphosis, in the lumbosacral region may be related to this type of injury.

Study Design: A retrospective cohort study., Objective: To evaluate the clinical and radiological efficacies of supplementing minimally invasive lateral lumbar interbody fusion (LLIF) with open posterior spinal fusion (PSF) in adult spinal deformity (ASD)., Summary of Background Data: Minimally invasive techniques have been increasingly applied for surgery of ASD. Few reports have been published that directly compare LLIF combined with PSF to conventional PSF for ASD., Methods: To evaluate the advantages of minimally invasive LLIF for ASD, patients who underwent minimally invasive LLIF followed by open PSF (combined group) were compared with patients who only underwent PSF (only PSF group). The clinical and radiological outcomes for deformity correction and indirect decompression were assessed. The occurrence of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) were also evaluated., Results: No significant differences were observed in the clinical outcomes of the Oswestry Disability Index (ODI), visual analog scale, and major complications including reoperations between the groups. No additional advantage was found for coronal deformity correction, but the restoration of lumbar lordosis in the combined group was significantly higher postoperatively (15.3° vs. 8.87°, P = 0.003) and last follow-up (6.69° vs. 1.02°, P = 0.029) compared to that of the only PSF group. In the subgroup analysis for indirect decompression for the combined group, a significant increase of canal area (104 vs. 122 mm) and foraminal height (16.2 vs. 18.5 mm) was noted. The occurrence of PJK or PJF was significantly higher in the combined group than in the only PSF group (P = 0.039)., Conclusion: LLIF has advantages of indirect decompression and greater improvements of sagittal correction compared to only posterior surgery. LLIF should be conducted considering the above-mentioned benefits and complications including PJK or PJF in ASD., Level of Evidence: 4.

Study Design: A retrospective comparative study., Objective: The aim of this study was to analyze the exact distal fusion level in the treatment of major thoracolumbar and lumbar (TL/L) adolescent idiopathic scoliosis (AIS) using rod derotation (RD) and direct vertebral rotation (DVR) following pedicle screw instrumentation (PSI)., Summary of Background Data: Proper determination of distal fusion level is a very important factor in deformity correction and preservation of motion segments in the treatment of major TL/L AIS., Methods: AIS patients with major TL/L curves (n = 64) treated by PSI with RD and DVR methods with a minimum 2-year follow-up were divided into AL3 (flexible) and BL3 (rigid) according to the flexibility and rotation by preoperative bending radiographs., Results: There was no significant difference in TL/L (major) curve between the AL3 and BL3 groups postoperatively (P = 0.933) and at the last follow-up (P = 0.144). In addition, there was no significant difference in thoracic (minor) and compensatory (caudal) curve postoperatively (thoracic curve: P = 0.828, compensatory curve: P = 0.976); however, there was a significant difference in compensatory (caudal) curve at the last follow-up (P = 0.041). The overall prevalence of unsatisfactory results was 28.1% (18/64 patients), and the prevalence was 15.2% (7/46) in the AL3 group and 61.1% (11/18) in the BL3 group, which was significantly different (P < 0.05)., Conclusion: Lowest instrumented vertebra (LIV) would be selected at L3 (EV) when the curve is flexible; L3 crosses CSVL with a rotation of less than grade II in preoperative bending radiographs. However, if the curve is rigid, LIV should be extended to L4 (EV + 1) in order to prevent the adding-on phenomenon in the treatment of major TL/L AIS using RD and DVR following PSI., Level of Evidence: 4.

Study Design: A retrospective comparative study., Objective: To compare pedicle subtraction osteotomy (PSO) and iliac fixation (ILF) without osteotomy as methods of correcting lumbar spine deformities due to degenerative sagittal imbalance (DSI) through the evaluation of the changes in spinopelvic alignment., Summary of Background Data: Many papers have reported the surgical results after PSO and ILF for patients with fixed adult deformities. However, little is known about the difference between PSO and ILF corrections of spinopelvic alignment in adults with DSI., Methods: DSI patients who had undergone PSO or ILF with a minimum of 2-year follow-up (FU) were retrospectively studied in PSO (n=30) or ILF (n=25) groups. Lumbar lordosis (LL), thoracic kyphosis (TK), and sagittal vertical axis (SVA) were measured as spinal parameters and pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) were used as measurements of pelvic parameters. Clinical outcomes were evaluated using a visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores., Results: There were no statistically significant differences between the PSO and ILF groups with regard to age and fused segments, but there were significant differences in operative time and estimated blood loss. Concerning spinal parameters, there were significant increases of LL and TK in PSO group immediate postoperatively (LL: P=0.014, TK: P=0.017) and at the 2-year FU (LL: P=0.021, TK: P=0.022), but no significant difference in SVA was evident between the 2 groups. Within the pelvic parameters, there was a significant increase of SS and decrease of PT in the ILF group immediate postoperatively (SS: P=0.013, PT: P=0.009) and at the 2-year FU (SS: P=0.024, PT: P=0.027), but the PI in both groups was not changed after surgery and there was no significant difference between 2 groups. VAS and ODI were significantly improved after surgery in both groups., Conclusions: The PSO group was better than the ILF group in the correction of the LL and TK, but not with regard to the pelvic parameters. The ILF group was superior in the correction of the pelvic orientation as compared with the PSO group when the PI was constant after surgery. Ultimately, ILF effectively achieves better correction of the pelvic parameters (SS and PT).

Purpose: To analyze pre- and postoperative spinopelvic parameters and sagittal profiles in lumbar degenerative kyphoscoliosis (LDK) patients who underwent surgery using iliac screw (IS) and the incidence and risk factor of radiological adjacent segment degeneration (ASD)., Methods: A total of 32 patients, who had undergone surgical correction and lumbar/thoracolumbar fusion with pedicle screws and IS instrumentation for LDK with a minimum 2-year follow-up, were included. Ten cases with ASD (group 1) and 22 cases without ASD (group 2) were compared to see pre- and postoperative change in sagittal view of spine and adjacent segment. Parameters of both groups were analyzed before and after surgery with each parameters being tested on correlativity. All deformity types of patients were classified using Scoliosis Research Society (SRS)-Schwab classification. Risk factors of ASD were evaluated using variables of SRS-Schwab classification., Results: Group 1, rather than group 2, showed significant increment in pelvic incidence (PI). Curve types, classified using SRS-Schwab classification, were all corrected using IS; and after correction, coronal curve type was N curve and PI minus lumbar lordosis (LL) and pelvic tilt showed tendency to decrease. Cases with preoperative sagittal vertical axis (SVA) more than 10 cm and with postoperative PI minus LL more than 20° were at higher risk of developing ASD., Conclusion: For those with high PI, it might be a risk to cause ASD. Maintaining normal thoracic and lumbar angle, correction of SVA less than 4 cm, and PI minus LL below 20° are proper ways to avoid ASD after surgery.

Objective: To explore the performance of three-dimensional (3D) isotropic T2-weighted turbo spin-echo (TSE) sampling perfection with application optimized contrasts using different flip angle evolution (SPACE) sequence on a 3T system, for the evaluation of nerve root compromise by disc herniation or stenosis from central to extraforaminal location of the lumbar spine, when used alone or in combination with conventional two-dimensional (2D) TSE sequence., Materials and Methods: Thirty-seven patients who had undergone 3T spine MRI including 2D and 3D sequences, and had subsequent spine surgery for nerve root compromise at a total of 39 nerve levels, were analyzed. A total of 78 nerve roots (48 symptomatic and 30 asymptomatic sites) were graded (0 to 3) using different MRI sets of 2D, 3D (axial plus sagittal), 3D (all planes), and combination of 2D and 3D sequences, with respect to the nerve root compromise caused by posterior disc herniations, lateral recess stenoses, neural foraminal stenoses, or extraforaminal disc herniations; grading was done independently by two readers. Diagnostic performance was compared between different imaging sets using the receiver operating characteristics (ROC) curve analysis., Results: There were no statistically significant differences ( p = 0.203 to > 0.999) in the ROC curve area between the imaging sets for both readers 1 and 2, except for combined 2D and 3D (0.843) vs. 2D (0.802) for reader 1 ( p = 0.035), and combined 2D and 3D (0.820) vs. 3D including all planes (0.765) for reader 2 ( p = 0.049)., Conclusion: The performance of 3D isotropic T2-weighted TSE sequence of the lumbar spine, whether axial plus sagittal images, or all planes of images, was not significantly different from that of 2D TSE sequences, for the evaluation of nerve root compromise of the lumbar spine. Combining 2D and 3D might possibly improve the diagnostic accuracy compared with either one.

Purpose: To assess the efficacy of a novel preemptive multimodal analgesic regimen for reducing postoperative pain and complications after primary lumbar fusion surgery. Preemptive multimodal analgesia is revealed to be an effective alternative to conventional morphine administration providing improved postoperative pain control with diminished side effects. However, an optimal regimen for spinal fusion surgery remains unknown., Methods: After Institutional Review Board approval, 80 patients who underwent primary lumbar 4-5 fusion surgery were randomly assigned to receive either only intravenous morphine or a preemptive multimodal (celecoxib, pregabalin, extended-release oxycodone, and acetaminophen) analgesic regimen. Postoperative pain and functional levels were measured by the visual analog scale (VAS) and Oswestry Disability Index (ODI), respectively, and intraoperative blood loss, postoperative Hemovac drain output, and nonunion rates were evaluated for complications., Results: No differences were observed in the patient demographics, intraoperative blood loss, postoperative Hemovac drain output, or nonunion rate between two groups. The VAS and ODI were lower at all postoperative time points, except the ODI on postoperative day 1 in patients randomized to receive the preemptive multimodal analgesic regimen. No major identifiable postoperative complications were observed in either treatment group., Conclusions: The preemptive multimodal analgesic combination in this study appears to be safe and effective after lumbar fusion surgery.

Purpose: To investigate volumetric changes in lumbar disc herniation (LDH) using three-dimensional measurements obtained by magnetic resonance imaging (MRI) and to identify possible factors affecting such changes., Methods: Between January 2004 and December 2011, 43 patients who underwent conservative treatment for LDH were enrolled. In all, 56 disc levels were investigated. MRI was performed on two or more occasions (minimally, at the initial visit and 6 months later). The volume of each herniated disc was determined. For each patient, disc migration, morphology, initial LDH size, and clinical outcome were evaluated., Results: The mean volumes of herniated discs at the initial and follow-up visits were 1,304.57 ± 837.99 and 993.84 ± 610.04 mm(3), respectively. The mean change in volume from the initial to the follow-up visit was 310.73 ± 743.60 mm(3). Volumes decreased at 35 disc levels and increased at 21 levels. The disc containment, the extent of LDH, the initial size of the herniated disc, and the degree of intactness of the posterior longitudinal ligament were significantly correlated with disc resorption and an increase in disc volume (p = 0.01, p = 0.018, p = 0.001, and p < 0.001, respectively). No significant association was evident between disc volumetric change and clinical outcome., Conclusions: We observed that LDH is a dynamic disease and that a herniated disc is not always spontaneously resorbed, in contrast to what has been reported previously. Alleviation of clinical symptoms can be achieved via conservative treatment even if the volume of the herniated disc changes. Spinal surgeons should not only present an option of initial non-surgical treatment to LDH patients but should also inform them that the LDH may change in size during daily activity or exercise.

The etiology of congenital scoliosis and its development remains unclear and has not yet been fully identified, even there are theories that congenital scoliosis could be derived from the failure of formation or failure of segmentation, which are etiologically heterogeneous with genetic, epigenetic, and environmental factors contributing to their occurrence. We reported a case of long-term follow-up after posterior vertebral column resection (PVCR) in both identical twins with similar congenital kyphoscoliosis at thoracolumbar levels. Twin I had been noticed by his parents to have asymmetry of his back at age 5 years, but no treatment was given. Twin II was first noticed to have a spinal problem at 11 years of age by his parents. Overtime, spine of both twins became further deviated to the left with kyphosis and was referred to our hospital. Both monozygotic twins were treated by PVCR and satisfactory results were demonstrated at 10-year follow-up.This case is the first report on the surgical treatment with PVCR, almost simultaneously, in both identical twins who had similar congenital vertebral anomalies causing kyphoscoliosis. Both identical twins with congenital kyphoscoliosis had undergone surgical correction by PVCR, anterior support with a mesh cage and posterior fusion using pedicle screws at the age of 14 years and achieved a satisfactory correction and a stable spine without curve progression with 10-year follow-up., Competing Interests: The authors have no funding and conflicts of interest to disclose. Institutional Review Board approval of Inje University Sanggye Paik Hospital (IRB No. 2015-02-019) was obtained before data collection and analysis.

Study Design: Retrospective cohort study., Objective: The aim of this study was to evaluate the clinical relevance of the SRS-Schwab classification for degenerative lumbar scoliosis (DLS)., Summary of Background Data: The SRS-Schwab classification has been presented and validated as a useful tool for adult spinal deformity (ASD). This classification includes various types of ASD (degenerative de novo scoliosis or adult form of idiopathic scoliosis). However, DLS has different clinical characteristics and pathophysiology compared with other forms of ASD., Methods: In this retrospective cohort study, 216 (146 conservatively treated and 70 surgically treated) DLS patients were enrolled. The average patient age was 72.1 ± 7.4 years. Clinical parameters for disability were measured using Oswestry disability index (ODI) and back and leg pain numerical rating scale. Radiographic parameters included SRS-Schwab sagittal modifiers (pelvic tilt [PT]; sagittal vertical axis [SVA];pelvic incidence-lumbar lordosis [PI-LL]), T1 pelvic angle, and coronal parameters (Cobb's angle [CA]; coronal imbalance [CI]; coronal deviation distance [CDD]; tilting angle [TA]). Correlations between clinical parameters and radiographic parameters were assessed and surgical rates along the SRS-Schwab sagittal modifiers were evaluated., Results: Only PI-LL as a sagittal radiographic parameter showed a weak correlation with clinical parameters (r = 0.137-0.176) (P < 0.05). Coronal parameters such as CA, CI, CDD, and TA also showed weak correlation with clinical parameters (r = 0.137-0.202) (P < 0.05). Multiple regression analysis identified CA, CI, CDD, and PI-LL to be correlated with clinical parameters. On analysis for clinical outcomes (surgical rates and patient self-reported disability) along the grades of the SRS-Schwab sagittal modifiers, PT and SVA were not related to higher surgical rates or disability., Conclusion: Even though some radiological parameters showed statistically significant results, correlation between radiological and clinical parameters was weak. Not only deformity but also other clinical factors should be considered when evaluating DLS., Level of Evidence: 4.

Purpose: 1. To investigate the incidence of closed-type PSIS in the Korean population. 2. To categorize the morphological features of Korean sacrum. 3. To measure the safe marginal length and angle for screw fixation considering the PSIS and course of the external iliac vein, using a Korean sacrum model., Methods: We performed our study in 160 sacra including the pelvic ring obtained from 80 Korean cadavers. The bony measurements were obtained by performing 1-mm computed tomography cuts from the L5 lumbar vertebra to the pelvic ring and excluding other structures. We evaluated the incidence of anatomic variation of the PSIS and measured the safe marginal length and angle for screw fixation considering the PSIS and course of the external iliac vein, using a Korean sacrum model., Results: Our study showed that the closed type of PSIS is more frequent in males than in females. The optimal angle for screw fixation is 16.91 ± 6.85 (°), while the left side S1 pedicle insertion angle is 16.00 ± 6.20 (°). The average Korean optimal screw length is 58.35 ± 14.90 (cm) for the right side and 55.89 ± 16.16 (cm) for the left side., Conclusion: With reference to these parameters, the optimal screw length and angle can be chosen and bicortical anteromedial screw fixation can be easily and safely performed.

Study Design: A retrospective study., Objective: To evaluate the surgical outcomes of posterior hemivertebra resection and short segment fusion with segmental pedicle screw fixation in congenital scoliosis in children younger than 10 years., Summary of Background Data: This is the first long-term follow-up on surgical outcomes of posterior hemivertebra resection and short segment fusion using segmental pedicle screw fixation in children younger than 10 years with congenital scoliosis., Methods: Patients with congenital scoliosis (n = 18) younger than 10 years at the time of the surgery were treated by posterior hemivertebra resection and bilateral pedicle screw fixation. The mean age at the time of surgery was 6.6 years (range, 2.6-9.8 yr). They were retrospectively studied with a mean follow-up of 11.4 years (range, 7.1-17.3 yr)., Results: The mean Cobb angle of the main curve was 34.4° before surgery, 8.6° after surgery, and 12.9° at last follow-up. In the compensatory cranial curve, the preoperative Cobb angle of 14.5° was corrected to 5.9° postoperatively and was 8.4° at last follow-up. In the compensatory caudal curve, the preoperative Cobb angle of 17.4° improved to 4° postoperatively and 6.6° at last follow-up. There were no crankshaft phenomena and no clinical and radiographical features suggestive of spinal stenosis during follow-up. There were no major vascular or neurological complications related to the pedicle screws., Conclusion: Posterior hemivertebra resection after pedicle screw fixation in congenital scoliosis is a safe and effective procedure that can achieve rigid fixation and deformity correction and restore spinal balance. This study showed that early posterior hemivertebra resection of congenital scoliosis before structural changes occur above or below can reduce fusion length, prevent curve progression, and effectively achieve a more satisfactory correction without hazardous iatrogenic spinal stenosis, crankshaft phenomena, or neurological complications., Level of Evidence: 3.

Object: This retrospective study was designed to evaluate the clinical outcomes and radiological findings after open lumbar discectomy (OLD) in patients who were followed up for 10 years or longer., Methods: The authors classified 79 patients who had a mean age (±SD) of 53.6±13.6 years (range 30-78 years) into 4 groups according to the length of their follow-up. Patients in Group 1 were followed up for 10-14 years, in Group 2 for 15-19 years, in Group 3 for 20-24 years, and in Group 4 for more than 25 years. In all of these patients, the clinical outcomes were assessed by using patients' self-reported scores on visual analog scales (VASs) measuring back and leg pain and by using scores from the Oswestry Disability Index (ODI). In addition, 10 radiological parameters suggesting degenerative changes or instability at the operated segment were recorded at various time points and used to calculate a numeric radiological finding (NRF) score by rating a presence for each finding of spinal degeneration or instability as 1., Results: The authors observed that OLD decreased pain and disability scores in all groups. Numeric radiological findings were highest in Group 4, and a significant correlation was detected between NRFs and VAS scores of back pain (p=0.039). In this cohort, the reoperation rate was 13.9% during a mean follow-up period of 15.3 years. Clinical outcomes tended to be most favorable in Group 1, representing patients who had OLD most recently, and they tended to deteriorate in the other 3 groups, indicating some worsening of outcomes over time. Degeneration of the spine at the operated level measured with radiographic methods tended to increase over time, but some stabilization was observed. Although spinal degeneration was stable, clinical outcomes deteriorated over time., Conclusions: This cross-sectional assessment of a retrospective cohort indicates that outcomes after OLD deteriorate over time. Increased back pain indicated a worsening of clinical outcomes, and this worsening was correlated with radiological findings of degeneration at the operated segment.

Background: Three-dimensional (3D) fast spin-echo sequence with variable flip-angle refocusing pulse allows retrospective alignments of magnetic resonance imaging (MRI) in any desired plane., Purpose: To compare isotropic 3D T2-weighted (T2W) turbo spin-echo sequence (TSE-SPACE) with standard two-dimensional (2D) T2W TSE imaging for evaluating lumbar spine pathology at 3.0 T MRI., Material and Methods: Forty-two patients who had spine surgery for disk herniation and had 3.0 T spine MRI were included in this study. In addition to standard 2D T2W TSE imaging, sagittal 3D T2W TSE-SPACE was obtained to produce multiplanar (MPR) images. Each set of MR images from 3D T2W TSE and 2D TSE-SPACE were independently scored for the degree of lumbar neural foraminal stenosis, central spinal stenosis, and nerve compression by two reviewers. These scores were compared with operative findings and the sensitivities were evaluated by McNemar test. Inter-observer agreements and the correlation with symptoms laterality were assessed with kappa statistics., Results: The 3D T2W TSE and 2D TSE-SPACE had similar sensitivity in detecting foraminal stenosis (78.9% versus 78.9% in 32 foramen levels), spinal stenosis (100% versus 100% in 42 spinal levels), and nerve compression (92.9% versus 81.8% in 59 spinal nerves). The inter-observer agreements (κ = 0.849 vs. 0.451 for foraminal stenosis, κ = 0.809 vs. 0.503 for spinal stenosis, and κ = 0.681 vs. 0.429 for nerve compression) and symptoms correlation (κ = 0.449 vs. κ = 0.242) were better in 3D TSE-SPACE compared to 2D TSE. 3D TSE-SPACE with oblique coronal MPR images demonstrated better inter-observer agreements compared to 3D TSE-SPACE without oblique coronal MPR images (κ = 0.930 vs. κ = 0.681)., Conclusion: Isotropic 3D T2W TSE-SPACE at 3.0 T was comparable to 2D T2W TSE for detecting foraminal stenosis, central spinal stenosis, and nerve compression with better inter-observer agreements and symptom correlation., (© The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Study Design: Retrospective cohort study., Objective: To investigate the fate of sclerosis and anterior osteophytes in the fused segments after instrumented lumbar fusion for degenerative lumbar disorders., Summary of Background Data: Sclerosis and osteophytosis are well-known radiographical findings, but little is known of their significance with regard to spontaneous resorption after spine fusion., Methods: Thirty patients (9 males, 21 females; 60 vertebra; mean age of 66.9 yr [45-86 yr]) were divided into a posterolateral fusion group (n = 14, 28 vertebrae) and a posterior lumbar interbody fusion group (n = 16, 32 vertebrae). Using serial radiographs obtained preoperatively; postoperatively at 3, 6, 12, and 24 months; and last follow-up, sclerotic areas of each involved vertebra were mapped and osteophyte lengths were measured., Results: Sclerosis and osteophytes decreased with time for the instrumented fusion. The decrease in sclerotic areas and osteophytes length was observed as early as 3 months postoperatively, and the significant changes between each time point were noted in initial 3- and 6-month intervals. In terms of the type of surgery, similar changes were noted in the posterolateral fusion and posterior lumbar interbody fusion groups., Conclusion: Resorption of osteophytes and sclerosis after instrumented spine fusion were observed. Significant resorption was noted at 3 and 6 months postoperatively. As well, most graft bone would be incorporated in postoperative 6 months. Resorption of osteophytes and sclerosis after instrumented spine fusion could be helpful to confirm the successful union., Level of Evidence: 4.

Study Design: A retrospective comparative study., Objective: To investigate adjacent segment pathology (ASP) after limited lumbar fusion in the treatment of degenerative lumbar scoliosis (DLS)., Summary of Background Data: The assessment of appropriate surgical techniques for DLS remains one of the most controversial topics in spinal surgery. So far, there has been no study specifically addressing why ASP shows different patterns with respect to different fusion levels after instrumented lumbar fusion for DLS., Methods: Fifty-nine patients were enrolled and divided into 2 groups with respect to the proximal fusion level: group I consisted of 29 patients who underwent fusion below the proximal neutral vertebrae, and group II consisted of 30 patients who underwent fusion to the proximal neutral vertebrae. Clinical and radiological assessments were performed with an average of 59.4 months of follow-up. The number of radiological findings for ASP was determined on the basis of a 7-point scale that gave 1 point for each radiological finding. The 2 groups were analyzed according to radiological ASP (RASP). The Oswestry Disability Index and visual analogue scale scores were recorded prospectively., Results: Overall, RASP developed in 16 (27.1%) patients. In group I, 12 (41.4%) of 29 patients, and in group II, 4 (13.3%) of 30 patients showed RASP. Group I yielded an average of 4.5 points, and group II, 1.8 points. RASP scores were much higher in group I than in group II, with statistical significance (P = 0.000). In group I, 4 patients underwent revision surgery, but in group II, only 1 patient did so., Conclusion: RASP displayed variance according to different fusion levels. RASP in group I showed similar patterns to the natural progression of DLS. It is suggested that fusion be included at least at the proximal neutral vertebrae to reduce RASP although RASP with different patterns is unavoidable., Level of Evidence: 4.

Introduction: Pure hyperextension thoracolumbar spinal fractures are unusual and occur primarily in patients with ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis due to the rigidity of the spine., Material and Methods: A 62-year-old female with osteoporosis presented with a significantly displaced fourth vertebral body fracture after being hit by a motorcycle. An imaging study showed widening of the vertebral height of L4 anteriorly with a horizontal fracture extending across the vertebral body. An in situ instrumented lumbar fusion from the second to fifth lumbar vertebrae was performed. Postoperatively, the patient complained of abdominal pain and difficulty in voiding. Computed tomography and intravenous pyelography showed that the right ureter was impinged between the fractured gaps of the vertebral body of L4., Results: Solid bony union was obtained with surgical intervention., Conclusions: This case reports a rare distractive extension injury in the lower lumbar spine with ureteral impingement. One should be aware of possible complications such as ureteral impingement following a pure hyperextension injury in the lower lumbar spine.

Study Design: Retrospective study., Objectives: To investigate the clinical feasibility and outcomes from direct lateral interbody fusion (DLIF) using autogenous bone grafts and percutaneous posterior instrumentation (PPI) for infectious spondylitis., Summary of Background Data: As one of the minimally invasive techniques, PPI has been attempted for various degenerative lumbar spine disorders combined with anterior lumbar interbody fusion or transforaminal lumbar interbody fusion. PPI has been played more roles recently as an internal fixation method for infectious spondylitis. However, the clinical outcomes of DLIF using an autogenous bone graft combined with PPI for infectious spondylitis have been rarely reported., Materials and Methods: Sixteen patients (mean age, 60.3 ± 18.8 y) who suffered from pyogenic spondylitis underwent single-stage DLIF using an autogenous iliac bone graft combined with PPI. Clinical and radiologic outcomes were evaluated by visual analog scale (VAS), Oswestry Disability Index (ODI), and eradication of primary disease. Radiologic outcomes were evaluated by changes of affected segmental lordosis and fusion status., Results: Bony fusion and eradication of primary disease were obtained in all patient except 1 case during the follow-up (mean, 31.3 ± 13.1 mo; range 14-46 mo). Preoperative VAS (7 ± 1.2) and ODI (61.3 ± 5.4) scores improved significantly at the last follow-up (VAS, 3.4 ± 1.5; ODI, 32.3 ± 15.4). C-reactive protein normalized at postoperative 20.1 ± 0.7 days (range, 15-28 d). Although height and lordosis in the affected segment were restored by surgery, all patients showed loss of the restored lordosis and height at the final follow-up. Loss of the restored lordosis and height were related to subsidence of the grafted bone., Conclusions: Minimally invasive PPI followed by debridement and DLIF was a feasible surgical alternative in our consecutive 16 cases of pyogenic spondylitis. In most cases, however the subsidence of anteriorly grafted fusion was inevitable despite successful fusion and eradication of the primary lesion.

Study Design: Retrospective cohort study., Objective: To identify the effect of cement augmentation for cephalad vertebral fracture after instrumented lumbar fusion., Summary of Background Data: Osteoporosis may contribute to cephalad vertebral fractures by an altered biomechanics in the adjacent segments due to the loss of motion at the fused segments. However, few studies on the treatment for cephalad fractures using bone cement augmentation after instrumented lumbar fusion have been published., Methods: Seventeen patients who had cephalad vertebral fractures after instrumented lumbar fusion underwent percutaneous vertebroplasty (PVP). All patients were divided into 2 groups according to the presence of intravertebral vacuum clefts (IVC) on plain radiographs and magnetic resonance imaging: group 1 consisted of 9 patients without an associated IVC and group 2 consisted of 8 patients with an IVC. The Oswestry Disability Index and the Visual Analogue Scale were recorded prospectively. The radiologic parameters of kyphotic deformity, vertebral height changes, and leakage of cement were studied., Results: The Oswestry Disability Index and Visual Analogue Scale scores in group 1 decreased after PVP, but the mean score in group 2 was higher than in group 1 at the last follow-up. The mean kyphosis measured 15.7±7.4 degrees preoperatively and 15.6±7.1 degrees at the final follow-up in group 1, and 16.9±8.8 degrees preoperatively and 27.2±8.8 degrees at the final follow-up in group 2.The mean preoperative anterior and posterior vertebral height ratio measured 0.6±0.2 preoperatively and 0.6±0.2 at the final follow-up in group 1, and 0.6±0.2 preoperatively and 0.5±0.2 at the final follow-up in group 2.The mean preoperative middle and posterior vertebral height ratio measured 0.5±0.1 preoperatively and 0.6±0.1 at the final follow-up in group 1, and 0.5±0.1 preoperatively and 0.4±0.2 at the final follow-up in group 2. Four patients underwent revision surgery in group 2 and 1 in group 1., Conclusions: Although PVP treatment may be a useful method for cephalad vertebral fractures after instrumented lumbar fusion in elderly patients with persistent unremitting back pain, recollapse of the vertebral body can occur after a PVP for cephalad or adjacent vertebral fractures with an IVC.

Object: The authors undertook this study to investigate the validity of the rationale for posterior dynamic stabilization using the Device for Intervertebral Assisted Motion (DIAM) in the treatment of degenerative lumbar stenosis., Methods: A cohort of 31 patients who underwent single-level decompression and DIAM placement for degenerative lumbar stenosis were followed up for at least 2 years and data pertaining to their cases were analyzed prospectively. Of these patients, 7 had retrolisthesis. Preoperative and postoperative plain lumbar radiographs obtained in all patients and CT images obtained in 14 patients were analyzed. Posterior disc heights; range of motion (ROM) of proximal, distal, and implant segments; lordotic angles of implant segments; percentage of retrolisthesis; and cross-sectional area and heights of intervertebral foramina on CT sagittal images were analyzed. Clinical outcomes were evaluated using visual analog scale scores and Oswestry Disability Index scores., Results: The mean values for posterior disc height before surgery, at 1 week after surgery, and at the final follow-up visits were 6.4 ± 2.0 mm, 9.7 ± 2.8 mm, and 6.8 ± 2.5 mm, respectively. The mean lordotic angles at the implant levels before surgery, at 1 week after surgery, and at the final follow-up visits were 7.1° ± 3.3°, 4.1° ± 2.7°, and 7.0° ± 3.7°, respectively. No statistically significant difference was found between the preoperative values and values from final follow-up visits for posterior disc height and lordotic angles at implant levels (p = 0.17 and p = 0.10, respectively). There was no statistically significant difference between the preoperative and final follow-up visit values for intervertebral foramen cross-sectional area and heights on CT images. The ROMs of proximal and distal segments also showed no significant decrease (p = 0.98 and p = 0.92, respectively). However, the ROMs of implant segments decreased significantly (p = 0.02). The average 31.4-month improvement for all clinical outcome measures was significant (p < 0.001)., Conclusions: Based on radiological findings, the DIAM failed to show validity in terms of the rationale of indirect decompression, but it did restrict motion at the instrumented level without significant change in adjacent-segment ROM. The clinical condition of the patients, however, was improved, and improvement was maintained despite progressive loss of posterior disc height after surgery.

Fractalkine (CX3CL1) and its receptor (CX3CR1) comprise a chemokine system involved in leukocyte recruitment and adhesion in chronic inflammatory disease, but its role in spinal diseases is unknown. The purpose of this study is to investigate the role of CX3CL1/CX3CR1 chemokine on hypertrophy of the ligamentum flavum (LF) in degenerative lumbar stenosis (DLS) compared with that of non-degenerative spinal condition (NDS) of the lumbar spine and correlation between expression of CX3CL1/CX3CR1 chemokine and thickness of LF. The mRNA concentrations of CX3CL1/CX3CR1 chemokine were analyzed in the surgically obtained LF specimens from DLS (n = 10) and NDS (n = 11) by real-time PCR. The localization of CX3CL1/CX3CR1 chemokine within the LF was determined using immunohistochemical study. Plasma levels of soluble FKN (sFKN) were measured by enzyme-linked immunosorbent assay, respectively. The thickness of the LF was measured with axial T1-weighted MRI. The cells that express CX3CL1/CX3CR1 chemokine ratio in the LF observed in DLS group were substantially higher than in NDS group. In ELISA, the plasma levels of sFKN was significantly increased in DLS compared with patients in the other groups (p = 0.006). There was greater CX3CL1/CX3CR1 expression in DLS as quantified by RT-PCR (p = 0.004, 0.010). Thickness of LF in patients was significantly correlated with serum CX3CL1 level (R(2) = 0.824, p = 0.003) and with mRNA expression of CX3CL1/CX3CR1 (R(2) = 0.671, p = 0.000) (R(2) = 0.514, p = 0.001). This study identified for the first time that increases in CX3CL1 and CX3CR1-expressing cells are significantly related to LF hypertrophy.

Purpose: To (1) clarify the role of various risk factors in the development of ASD, (2) compare instrumentation configuration with the development of ASD, (3) correlate the radiological incidence of ASD and its clinical outcome and (4) compare the clinical outcome between patients with radiological evidence of ASD and without ASD., Methods: This study prospectively examined 74 consecutive patients who underwent instrumented lumbar/lumbosacral fusion for degenerative disease with a minimum follow-up of 5 years. Among the patients, 68 were enrolled in the study. All of the patients had undergone preoperative radiological assessment and postoperative radiological assessment at regular intervals. The onset and progression of ASD changes were evaluated. The patients were divided in two groups: patients with radiographic evidence of ASD (group 1) and patients without ASD changes (group 2). Comprehensive analysis of various risk factors between group 1 and group 2 patients was performed. The Visual Analog Scale (VAS) was used to evaluate the clinical outcome and the functional outcome was evaluated using the Oswestry Disability Index (ODI) before and after surgery along with radiological assessment., Results: Radiographic ASD occurred in 20.6% (14/68) of patients. Preoperative disc degeneration at an adjacent segment was a significant risk factor for ASD. Other risk factors such as the age of a patient at the time of surgery, gender, preoperative diagnosis, length of fusion, instrumentation configuration, sagittal alignment and lumbar or lumbosacral fusion were not significant risk factors for the development of ASD. There was no correlation between ASD and its clinical outcome as determined at the final follow-up session. In addition, clinical outcome of patients with ASD and without ASD were not comparable., Conclusions: Patients with preoperative disc degeneration at an adjacent segment were more at risk for the development of ASD. Other risk factors including instrumentation configuration were not significantly associated with ASD. There was no correlation between both the radiological development of ASD and its clinical outcome and the clinical outcome of patients with and without ASD.

Object: In this paper the authors' goal was to determine the factors associated with the progression of degenerative lumbar scoliosis (DLS)., Methods: Twenty-seven patients (3 men and 24 women; mean age 64.9 years) with more than 10° of lumbar scoliosis at baseline were monitored for a mean period of 10 years. The radiological evaluation included measurement of the scoliosis angle using the Cobb method, the direction of the scoliosis, the relationship between the intercrest line and the L-5 vertebra, lateral listhesis, segmental angle, distance from the center of the sacral line to the apical vertebra, degenerative listhesis anteriorly or posteriorly or both, and lordosis angle. In addition, the lateral osteophyte difference, disc index, and severity of osteoporosis were measured. The pain and disability outcomes were assessed using the visual analog scale and the Oswestry Disability Index (ODI) relative to severity of the angle of scoliosis., Results: The mean initial and final scoliosis angles were 14° ± 5.4° and 25° ± 8.5°, respectively. The initial disc index at the L-3 vertebra (Spearman ρ = 0.7, p < 0.001), the sum of the segmental wedging angles above and below the L-3 vertebra (ρ = 0.6, p < 0.001), and the initial disc index at the apical vertebra (ρ = 0.6, p < 0.001) were correlated with the last follow-up angle of the scoliosis. By contrast, there was no statistically significant correlation between the initial segmental angles at L2-3 and L3-4 and the final follow-up scoliosis angle (ρ = 0.2, p = 0.67; and ρ = 0.1, p = 0.22; respectively). When the authors separated the patients into 3 groups according to the sum of the segmental angles above and below L-3 (< 5°, 5° to 10°, and > 10°), they found that 3 (42.9%) of 7, 8 (66.7%) of 12, and 6 (75.0%) of 8 patients in the 3 groups showed increases of greater than 10° in scoliosis angle. The mean distance from the center of the sacral line to the apical vertebra was 36.0 ± 9.7 mm, and the distance correlated with the measurement of the last follow-up angle of the scoliosis (ρ = 0.6, p < 0.001). The mean angle of the scoliosis was significantly greater when the intercrest line passed through the L-5 or L4-5 disc space than when the line passed through the L-4 vertebral body (31.4° ± 7.9° vs 21.8° ± 6.7°, p = 0.01). The ODI correlated with the measurement of the angle of the scoliosis (ρ = 0.6, p < 0.001). Age, sex, osteoporosis, the direction of the scoliosis, listhesis of coronal and sagittal planes, the lateral osteophyte difference, and the vertebral body index did not correlate with curve progression., Conclusions: The findings of this study demonstrated that the progression of DLS was affected by the relationship between the intercrest line and the L-5 vertebra. When L-5 was deep seated, progression of DLS was found. Asymmetrical change in the disc space above and below the L-3 or apical vertebra may also be an important predictor of curve progression.

Study Design: Comparative genomic hybridization (CGH) microarrays., Objective: To identify genomic copy number variations (CNVs) in degenerative lumbar scoliosis (DLS) patients, and investigate the possibility of genetic predisposition in DLS., Summary of Background Data: Genome scanning technology enables search for presence of CNVs. CGH microarray is a useful procedure in a genome-wide study., Methods: Among 45 consecutive patients who were diagnosed as DLS, 15 patients who manifested greatest Cobb's angle were selected for the array-CGH based CNV analysis. Control group was blood samples from 58 individuals without DLS. Oligonucleotide CGH microarray was utilized to analyze the CNV. Gene searches were performed for CNV DNA with significant gene-dosage difference. Validation qualitative PCR(qPCR) was performed at 3 genetic loci: at chromosome 2--TMEM163 gene, at chromosome 16--ANKRD 11 gene, and at chromosome 18--NFATC1 gene., Results: Genomic gains and losses were observed using the oligonucleotide CGH microarray. Identified CNVs were 446 ± 129 per individual. Gain- and loss-CNVs were identified as 196 ± 24 and 250 ± 110, respectively. The length of total CNV per individual was 30,946,730 ± 31,658,175 bp, and mean CNV-length was 61,017 ± 40,620 (median length 6411 ± 1994). Comparison with control group revealed 260 CNVs, which were significant (P < 10(-3)). Validation qPCR for gene-dosage comparison of DLS group DNA versus control group DNA in TMEM163 (P < 0.001); ANKRD 11 (P = 0.000); and NFATC1 (P = 0.000) gene showed significant difference., Conclusion: Various whole-genome CNVs specific to DLS patients were observed. Validation qPCR confirmed significantly different gene-dosages for TMEM163, ANKRD 11, and NFATC1 genes. We consider that the expression of DLS is supported by various typical CNV-associated structural variants of the genome.

Study Design: A case report and review of the literature., Objectives: To report a rare case of a vertebral compression fracture in the middle of fused segments in the absence of a history of trauma, and to investigate the contributory factors., Summary of Background Data: Few articles have been published on vertebral fractures among fused segments. However, several articles have addressed fractures at juxtafused segments after implant removal. To the best of the authors' knowledge, only one case of compression fracture within fused segments has been previously reported., Methods: This study involved the case of a 62-year-old woman with vertebral compression fracture of L4 within a solid fused segment region after implant removal. An investigation was conducted to identify the factors that contributed to this compression fracture., Results: Plain radiographs and bone scanning showed a compression fracture of L4 within a region of fused segments (L3-S1) after implant removal without the history of injury. BMD revealed osteopenia of -2.3 SD on the neck of the femur. The patient's symptoms were relieved by conservative treatment. The contributory factors may have been persistent anterior motion, osteopenia and/or osteoporosis, and a subcortical substance defect associated with screw tracks after implant removal., Conclusion: Vertebral compression fractures in solid fused segments may occur as a complication of implant removal. Accordingly, if spinal implant removal is needed for revision surgery, surgeons should be aware of this significant complication.

Study Design: Prospective cohort study., Objective: To determine: (1) patterns of bone graft volumetric changes, (2) whether different fusion methods, numbers of fusion segments, and range of fusion affect bone graft volumetric changes, and (3) whether these changes affect clinical and functional outcomes after surgery., Summary of Background Data: Bone graft volumetric change is likely to importantly determine successful fusion. However, despite the importance of graft volumetric changes, little information is available on bone graft volumetric changes after instrumented fusion., Methods: Thirty-one patients with lumbosacral disease who underwent decompression and instrumented spinal fusion using autologous iliac bone graft were included in this study. Patients were classified into 3 major categories, based on fusion methods, the number of fusion segments, and range of fusion, namely, (1) the posterolateral fusion and the posterior lumbar interbody fusion groups, (2) the one-segment fusion and 2-segment fusion groups, and (3) the floating fusion (fusion to L5) and fixed fusion (fusion to S1) groups. To evaluate bone graft volumetric changes, computed tomography scans were performed. Group graft volumes were compared, and Oswestry Disability Index and visual analogue scales scores were obtained to evaluate clinical and functional outcomes., Results: Initial graft volumes had decreased by 8% at 6 months and by 26.3% between 6 and 12 months after surgery (P = 0.0025, P = 0.0001, respectively). Mean group bone graft volume losses at 5 years after surgery were not significantly different between the posterolateral fusion and posterior lumbar interbody fusion groups or the floating fusion and fixed fusion groups (P = 0.722, P = 0.076, respectively). However, mean bone graft volume loss was significant greater in the 2-segment fusion group than in the one-segment fusion group (P = 0.007). No statistical difference in visual analogue scales and Oswestry Disability Index score decreases were observed between the groups. Mean graft bone volume loss during 5 years increased with initial graft volume (r = 0.525, P = 0.003). However, ratios of volume loss over 5 years versus initial graft volume decreased with initial graft volume (r = -0.459, P = 0.011)., Conclusion: One-third of initial bone grafts were found to be resorbed over 5 years and the majority of this resorption was found to occur between 6 months and 1 year after instrumented lumbar/lumbosacral fusion. Furthermore, bone graft volumetric changes were not affected by fusion methods or ranges of fusion, and did not affect clinical or functional outcomes. Although bone graft volume loss was found to increase with initial graft volume, larger bone grafts were found to result in a larger fusion mass.

Objectives: The surgical approach that should be used for degenerative spondylolisthesis (DS) is a controversial issue. Decompression and posterolateral fusion (PLF) with or without lumbar interbody fusion is widely used. Many studies have compared the outcomes of these 2 approaches, but the appropriate indications for these approaches are still unclear. The authors retrospectively studied the effects of posterior lumbar interbody fusion (PLIF) after PLF for the treatment of DS., Methods: Forty patients who underwent single level decompression and posterior instrumentation for DS at L4-5 and were followed for at least 2 years were retrospectively studied. The patients were divided into 4 groups: the stable PLF group (S-PLF, n=13); the stable PLF with additional PLIF group (S-PLIF, n=11); the unstable PLF group (U-PLF, n=8); and the unstable PLF with additional PLIF group (U-PLIF, n=8). Clinical and radiographic comparisons were carried out between the S-PLF and S-PLIF groups, and between the U-PLF and U-PLIF groups., Results: Clinical assessments, using the improvements of the Oswestry Disability Index (ODI) and the Visual Analog Scale (VAS), were statistically significantly different between the 2 unstable groups (DeltaU-PLF DeltaS-PLIF, P=0.029), and the disc height increment was significantly different between the 2 stable groups (DeltaS-PLF

Study Design: A prospective cohort study., Objective: To determine the cause-effect relationship between fusion and sacroiliac joint (SIJ) degeneration after instrumented posterolateral lumbar or lumbosacral fusion., Summary of Background Data: Adjacent segment degeneration following spinal fusion has attracted considerable attention. However, little attention has been paid to the SIJ, which is one of the adjacent joints., Methods: This study prospectively examined 37 patients, who underwent instrumented posterolateral lumbar/lumbosacral fusion from July 1997 to October 1998. Among them, 32 patients were included in this study and defined as the fusion group (male/female: 10/22, mean age: 64 years). The fusion group was divided into 2 subgroups according to the range of fusion. Group 1 had floating fusion (fusion to L5) and included 22 patients (male/female: 7/15, mean age: 65.6 years). Group 2 had fixed fusion (fusion to S1) and included 10 patients (male/female: 3/7, mean age: 60.5 years). Thirty-four age-matched normal individuals (male/female: 18/16, mean age: 64.5 years) were recruited as a control group. SIJ degeneration was assessed by confirming the absence of degeneration in the SIJ by computed tomography scans before surgery and 2 weeks after surgery. The SIJ was evaluated again by taking computed tomography scans at 1 year and 5 years after surgery. The incidence of SIJ degeneration was evaluated and compared (fusion group vs. control group; group 1 vs. group 2). The clinical outcomes were evaluated using the Visual Analog Scales (VAS) and Oswestry Disability Index (ODI) before surgery and at the final follow-up., Results: The incidence of SIJ degeneration in the fusion group was 75% (24/32), which was significantly higher than that of the control Group 38.2% (13/34) (P < 0.05). The incidence of SIJ degeneration (bilateral and unilateral) and bilateral SIJ degeneration was higher in group 2 than in group 1 (P = 0.028 and 0.04, respectively). The incidence of SIJ degeneration was not associated with the number of fusion segments. At the 5-year follow-up, the patients in groups 1 and 2 reported significant improvements in the VAS and ODI scores compared with the preoperative scores. However, there was no significant difference in the decrease in VAS and ODI scores between the 2 groups (P = 0.145 and 0.278, respectively)., Conclusion: Instrumented posterolateral lumbar/lumbosacral fusion can be a cause of SIJ degeneration. SIJ degeneration develops more often in patients undergoing lumbosacral fusion regardless of the number of fusion segments.

Study Design: A retrospective clinical study., Objective: To assess the results of anterior strut grafting and the loss of the reduction in anterior interbody fusion and anterior interbody fusion combined with posterior instrumental fusion in pyogenic spondylodiscitis., Summary of Background Data: Resorption of the anterior graft is an ominous sign following most anterior surgery. Thus, additional posterior instrumentation has been used to prevent collapse of the anterior graft. However, its effect is controversial, and few studies have examined the fate of the anterior strut graft., Methods: Twenty-four consecutive patients underwent surgical treatment for pyogenic spondylodiscitis. The patients were divided into Group I (anterior interbody fusion) and Group II (anterior interbody fusion + posterior instrumented fusion). The sagittal angle, intervertebral height, and complications relating to the anterior graft were compared., Results: Solid bone fusion was achieved in 23 (95.8%) patients. The sagittal angle and the intervertebral height were similar in Groups I and II (P = 0.61, P = 0.89, respectively). In Groups I and II, the postoperative sagittal angle was maintained until 1 month after surgery (P > 0.05), but it decreased significantly by 3 months after surgery (P < 0.05). In Groups I and II, intervertebral height correction was maintained until 1 month after surgery (P > 0.05), but by 3 months after surgery, it had collapsed significantly (P < 0.05). Subsidence of the graft occurred through the damaged endplate. Group I included 1 case of graft dislodgement necessitating revision; there were no such cases in Group II. There were no recurrences of infection in either group., Conclusion: Reduction of intervertebral height and loss of sagittal profile occurred in both groups. Complications relating to the bone graft were more common in Group I than in Group II. Despite loss of correction, both groups had a high fusion rate without recurrence of infection. The reduction of intervertebral graft height appears to be the result of destruction of the endplate either due to surgical debridement or the infective process.

Study Design: Human intervertebral disc was obtained for the study of hypoxia inducible factor (HIF)-1alpha and apoptosis using immunohistochemical staining., Objective: To study the expression of HIF-1alpha and apoptosis in herniated lumbar discs., Summary of Background Data: The presence of HIF-1alpha in human chondrocytes and rat intervertebral discs has been proven; however, to our knowledge, its expression in human intervertebral disc cells has not been reported. Apoptosis of the human intervertebral disc appears as a degenerative change caused by the aging of the intervertebral disc. To our knowledge, there is no reported study showing the correlation between apoptosis and HIF-1alpha in the human intervertebral disc., Methods: There were 15 human intervertebral discs stained for HIF-1alpha immunohistochemically, and apoptosis was detected using the terminal deoxynucleotidyl transferase mediated-dUTP nick end labeling method. On average, the patients were 32.9 years old. The intervertebral discs were divided into noncontained (9 patients) and contained (6) groups. For the control group, 5 disc samples were used., Results: The expression of HIF-1alpha was visualized in every case, with an average of 62.2% +/- 9.5% in the noncontained group, 30.5% +/- 3.6% in the contained group, and 11.4% +/- 9.3% in the control group. Apoptosis occurred in 74.3% +/- 7.3% of the cells in the noncontained group, 42.8% +/- 5.5% of the cells in the contained group, and 28% +/- 8.4% of the cells in the control group. HIF-1alpha and apoptosis expressions were both observed more frequently in the noncontained disc herniation group (P < 0.001). The correlation analysis between the degree of HIF-1alpha expression and apoptosis was also statistically significant., Conclusions: HIF-1alpha and apoptosis physiologically occur in human beings. Their expression was the highest in the noncontained group. HIF-1alpha may play a crucial role for the survival of disc cells and resorption of the herniated disc in human intervertebral discs.

Study Design: Immunohistochemical study was done by harvesting articular cartilage of the facet joints during the decompressive surgery for spinal stenosis., Objectives: To observe the expression of estrogen receptor on the articular cartilage of the facet joints in degenerative spondylolisthesis (DS) SUMMARY OF BACKGROUND DATA: Few attempts have been made to evaluate the effect of sex-hormone, although DS is more common in females than in males., Methods: After harvesting the articular cartilage of the facet joints in 17 DS and in 15 spinal stenosis (SS) patients, the expression of estrogen receptor and the severity of facet arthritis were observed by H-E and immunohistochemical staining, respectively. Measurements of both staining were made by using a semiquantitative analysis., Results: The significantly increased expression of estrogen receptor correlated with the severity of facet arthritis (r = 0.78, P < 0.05). There was a significantly increased expression of estrogen receptor of the facet joint in DS compared with SS (P < 0.01). The histologic-histochemical grading of cartilage lesion in DS was 12.4 (SEM, 0.6), which was significantly higher than in SS (P < 0.05)., Conclusions: These findings suggest that the higher expression of estrogen receptor might aggravate degenerative change of the facet articular cartilage and might also be considered one of the causative factors for DS in postmenopausal women.

The recommended surgical options for postoperative wound infections after instrumented spine surgery include a wide debridement and irrigation with antibiotics. In most cases, implant removal is not recommended for a solid fusion. However, there are few reports on the treatment choices for persistent postoperative wound infections following a posterior lumbar interbody fusion (PLIF) using cages. This paper reviewed ten patients referred to our department, who underwent revision surgery for a postoperative, deep infection after a PLIF with cages. The surgery included an anterior radical debridement and interbody fusion with removal of all implants. The clinical and laboratory results, including a bacteriologic study for the causative organism and the radiological changes, were analyzed. All patients complained of persistent severe back pain after the primary surgery. MRSA was the main organism found in these patients (five cases). Complete bony fusion was obtained in nine patients (90%). In one patient, back pain and radiating pain prevented him from returning to his original work. Despite the anterior interbody fusion with an autogenous iliac bone graft, all cases had a complete collapse of the intervertebral disc space, without a dislodgement or collapse of the graft bone. The mean loss of the height and lordosis in the involved segment was 12.7 mm (range 4-46 mm) and 5.6 degrees (range 0-15 degrees ), respectively. Anterior radical debridement with the removal of all implants would be an effective way to manage patients with postoperative spondylitis after a PLIF using cages.

Study Design: A case of bilateral pedicle stress fracture is reported, and the literature is reviewed., Objectives: To report the rare case of bilateral pedicle stress fracture after instrumented posterolateral fusion, and to investigate the contributing factors., Summary of Background Data: A 62-year-old man underwent revision spinal surgery for adjacent-segment degeneration. Decompression and instrumented posterolateral fusion from L1 to L3 were performed after removal of the previously inserted pedicular screws. In the patient's history, he had undergone L3-L5 instrumented posterolateral fusion for spinal stenosis 6 years previously. At 1 year after the revision surgery, he presented with severe progressive low back pain. Computer-assisted tomogram and bone scan demonstrated bilateral L4 pedicle stress fracture. To the best of the authors' knowledge, only two cases of pedicle stress fracture after lumbar posterolateral fusion have been reported., Methods: This study reviewed the reported patient's medical record, his imaging studies, and related literature. The possible factors contributing to bilateral pedicle stress fractures were investigated., Results: In the reported case, the features of radiographic studies confirmed bilateral pedicle stress fracture. The involved vertebra was L4. In all three cases reported so far, including the current case, the site of the pedicle stress fracture was at the junction of the pedicle and vertebral bodies., Conclusions: Bilateral pedicle stress fracture occurs as a complication of posterolateral lumbar fusion. Pedicle weakening by prior inserted screws and persistent anterior motion after posterolateral fusion are the contributing factors.

Study Design: A case report and review of the literature are presented., Objective: To describe an unusual simple bone cyst involving the pedicle of lumbar spine., Summary of Background Data: To the authors' knowledge, only nine cases of a simple bone cyst involving the spine have been reported. Most of these reports have described mild back or neck pain because the presenting symptoms or cysts were found incidentally. In the reported case, acute severe back pain with radiating pain developed. Therefore, the study focus was on the unusual location, the presenting symptoms, and its spinal involvement., Methods: A cystic lesion involving the left pedicle of the first lumber vertebra was identified in a 53-year-old woman with sudden-onset severe back pain with pain radiating to the left leg. Surgical resection was undertaken along with review of the patient's medical record, imaging studies, microscopic findings of the lesion, and the related literature., Results: Microscopic examination of the cystic lesion corresponded with the findings of a simple bone cyst. A thin fibrous membrane with reactive bone formation was identified without evidence of hemorrhage. A favorable result was achieved by surgical resection., Conclusions: This case study suggests that a simple bone cyst may be found in any portion of the spine, including the pedicle. Severe resting pain would be elicited by a pathologic fracture of the pedicle. Direct nerve compression by the fractured fragment and chemical irritation by cystic fluid would be compatible with the observed clinical manifestations.

A study was performed to determine which magnetic resonance (MR) imaging findings are useful in discrimination between metastatic compression fractures and acute osteoporotic compression fractures of the spine. The MR imaging findings in 27 patients with metastatic compression fractures and 55 patients with acute osteoporotic compression fractures were compared by using the chi(2) test. MR imaging findings suggestive of metastatic compression fractures were as follows: a convex posterior border of the vertebral body, abnormal signal intensity of the pedicle or posterior element, an epidural mass, an encasing epidural mass, a focal paraspinal mass, and other spinal metastases. MR imaging findings suggestive of acute osteoporotic compression fractures were as follows: a low-signal-intensity band on T1- and T2-weighted images, spared normal bone marrow signal intensity of the vertebral body, retropulsion of a posterior bone fragment, and multiple compression fractures. The signal intensity on fast spin-echo T2-weighted images obtained without fat suppression played little role in distinguishing between metastatic compression fractures and acute osteoporotic compression fractures., (Copyright RSNA, 2003.)

Background: To investigate the incidence and risk factors of coronal vertical vertebral body fracture (CV-VBF) during lateral lumbar interbody fusion (LLIF) for degenerative lumbar disease. Methods: Clinical data, including age, sex, body mass index, and bone mineral density, were reviewed. Radiological assessments, such as facet joint arthrosis, intervertebral disc motion, index disc height, and cage profiles, were conducted. Posterior instrumentation was performed using either a single or staged procedure after LLIF. Demographic and surgical data were compared between patients with and without VBF. Results: Out of 273 patients (552 levels), 7 (2.6%) experienced CV-VBF. Among the 552 levels, VBF occured in 7 levels (1.3%). All VBF cases developed intraoperatively during LLIF, with no instances caused by cage subsidence during the follow-up period. Sagittal motion in segments adjacent to VBF was smaller than in others (4.6° ± 2.6° versus 6.5° ± 3.9°, P = 0.031). The average grade of facet arthrosis was 2.5 ± 0.7, indicating severe facet arthrosis. All fractures developed due to oblique placement of a trial or cage into the index disc space, leading to a nutcracker effect. These factors were not related to bone quality. Conclusions: CV-VBF after LLIF occurred in 2.6% of patients, accounting for 1.3% of all LLIF levels. A potential risk factor for VBF involves the nutcracker-impinging effect due to the oblique placement of a cage. Thorough preoperative evaluations and surgical procedures are needed to avoid VBF when considering LLIF in patients with less mobile spine. [ABSTRACT FROM AUTHOR]