Spinopelvic parameters in degenerative spondylolisthesis

The purpose of this study was to compare various sagittal spinopelvic parameters between patients with and without degenerative lumbar spondylolisthesis (DLS). A total of 165 patients who underwent surgery for low back and/or radicular pain were divided into two groups: those without DLS (non-DLS group; n = 85) and those with DLS (DLS group; n = 80). In all sagittal spinopelvic parameters, no significant difference was found between the non-DLS and DLS groups. The mean pelvic incidence (PI) value of the DLS group (56.4°) was almost similar to that of the non-DLS group (57.5°). The cross-sectional ratio of lumbar musculature was significantly smaller in the DLS group than in thenon-DLS group (p = 0.046). Contrary to the results of previous studies, a high PI may not be a predisposing factor for DLS development. Atrophy of back extensor muscles may play a role in the pathogenesis of DLS.

Does stopping at C7 in long posterior cervical fusion accelerate the symptomatic breakdown of cervicothoracic junction?

OBJECT

To compare the clinical and radiological outcomes between patients with long posterior cervical fusion (PCF) in which fusion stopped at C7 versus patients in which fusion crossed the cervicothoracic junction (CTJ).

METHODS

The patients were divided into 2 groups on the basis of the lower-most instrumented vertebra (LIV); C7 group patients (n = 25) and upper thoracic (UT) group (n = 21). We analyzed the visual analogue scale of arm/neck pain, Japanese Orthopedic Association (JOA) score, and neck disability index (NDI). And we also measured the following parameters: (1) pseudomotion of fused segments; (2) C2-C7 sagittal vertical axis; (3) T1 slope; and (4) C2-C7 lordosis.

RESULTS

Arm and neck pain were similar in both groups pre- and postoperatively. Interestingly, mean postoperative NDI score in the UT group was significant worse when compared with the C7 group (9.7±4.6 vs. 14.2±3.7, p = 0.006). Although UT patients had longer fusion levels, the fusion rates were not significantly different between the C7 and UT groups (96.0% vs. 90.5%; p = 0.577). The radiographic parameters did not show any significant differences between the groups at final follow-up.

CONCLUSIONS

Our study demonstrates that multi-level PCF stopping at C7 does not negatively affect C7-T1 segment failure, fusion rate, neck pain, neurologic outcomes, and global sagittal alignment of the cervical spine. Hence, it is unnecessary to extend the long PCF levels caudally across the healthy CTJ for fear of development of adjacent segmental disease (ASD) at the C7-T1 segment.

Effect of osteoporosis on the clinical and radiological outcomes following one-level posterior lumbar interbody fusion

BACKGROUND

Cage subsidence or pedicle screw loosening following lumbar fusion surgery is frequently reported in osteoporotic patients. However, few studies have analyzed clinical as well as radiological outcomes after such surgeries as a function of bone mineral density. We aimed to evaluate the impact of osteoporosis on the clinical and radiological outcomes of patients who underwent one-level posterior lumbar interbody fusion (PLIF).

METHODS

Fifty-five non-osteoporotic (T-score ≥ -1.0) and 31 osteoporotic (T-score ≤ -2.5) patients who underwent one-level PLIF were followed up for >2 years. Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and EuroQol 5-Dimension (EQ-5D) parameters were assessed. Fusion success was identified with dynamic plain radiographs and computed tomography. Pedicle screw loosening and cage subsidence were evaluated. The clinical and radiological parameters were compared between osteoporotic and non-osteoporotic patients. Subgroup analysis was performed on cage subsidence or screw loosening.

RESULTS

Although VAS score for back pain was higher in osteoporotic patients than in non-osteoporotic patients at 6 months postoperatively (3.3 vs. 2.2, P = 0.062), this difference disappeared at 1 year postoperatively (2.9 vs. 2.5, P = 0.606). However, no differences were noted between the groups in ODI and EQ-5D grades. Cage subsidence (65.4% vs. 17.6%, P < 0.001) and screw loosening rates (32.3% vs. 12.7%, P = 0.029) were significantly higher in osteoporotic patients than in non-osteoporotic patients, but fusion rate did not differ between the groups. Although clinical outcomes did not differ between those who had cage subsidence or screw loosening and those who did not, fusion rate was lower in those who showed screw loosening than those who did not (71.4% vs. 93.9%, P = 0.038).

CONCLUSIONS

Higher cage subsidence and pedicle screw loosening rates in osteoporotic patients did not significantly affect the clinical outcomes, but screw loosening, which occurred more frequently in older patients, significantly reduced the fusion success rate. Thus, PLIF procedure may be a good surgical treatment option to achieve good clinical outcomes, even in osteoporotic patients despite higher rates of cage subsidence and pedicle screw loosening. However, surgeons should monitor screw loosening because of its significant association with non-union.

L1 incidence reflects pelvic incidence and lumbar lordosis mismatch in sagittal balance evaluation

Retrospective study.To investigate the radiologic and geometrical association between L1 incidence (L1I) with pelvic incidence/lumbar lordosis (PI/LL) mismatch and T1 incidence (T1I) with PI/LL/thoracic kyphosis (TK) mismatch.The relationship between PI and LL is not clear, and it might be because of the absence of a direct radiologic parameter to represent PI/LL mismatch. To the best of our knowledge, this is the first report on a direct radiologic parameter for representing PI/LL mismatch.This study is a retrospective review of 146 patients who underwent anteroposterior and lateral standing radiographs of the whole spine. L1I was defined as the angle between the line perpendicular to the L1 upper endplate and the line connecting the midpoint of the sacral endplate to the center of both femoral heads. T1I was defined as the angle between the line perpendicular to the T1 upper endplate and the line connecting the midpoint of the sacral endplate to the center of both femoral heads. Both were validated using the Pearson correlation coefficient and linear regression analysis.Radiologically measured L1I and T1I were coterminous with calculated measurements of ΔPI/LL and ΔPI/LL/TK in terms of means and standard deviations, respectively. Excellent correlations were found between L1I and ΔPI/LL, and T1I and ΔPI/LL/TK (R = 0.997, P < .01; R = 0.981, P < .01, respectively). In linear regression analysis, the slope and intercept of L1I were 0.991 and -0.041, with a predictability of 99.4% (R = 0.994), and those of T1I were 0.990 and -0.026, with a predictability of 99.0% (R = 0.990), respectively.L1I and T1I were strongly correlated with PI/LL mismatch and PI/LL/TK mismatch, respectively. L1I and T1I are direct parameters that represent PI/LL mismatch and PI/LL/TK mismatch. They would be useful in analyzing sagittal balance.

LEVEL OF EVIDENCE

Level 3.

Radiological risk factors for progression of ossification of posterior longitudinal ligament following laminoplasty

BACKGROUND CONTEXT

Research shows the progression of ossification of the posterior longitudinal ligament (OPLL) following decompressive surgery for cervical myelopathy, particularly in cases presenting with continuous or mixed radiographic types. To date, no study has investigated OPLL progression within each motion segment.

PURPOSE

To evaluate progression of cervical OPLL in each motion segment using a novel system of classification, and to identify risk factors for OPLL progression following laminoplasty.

STUDY DESIGN/SETTING

Retrospective case series.

PATIENT SAMPLE

This study included 34 patients (86 segments) with cervical myelopathy secondary to OPLL.

OUTCOME MEASURES

Clinical and radiological data (plain radiographs and computed tomography [CT]) were obtained.

METHODS

Clinical data from 34 patients (86 segments) with cervical myelopathy secondary to OPLL were evaluated retrospectively. All subjects had undergone laminoplasty at a single center. Sagittal reconstructive CT images were used to measure OPLL thickness in each segment. Ossified masses were classified into four types according to the degree of disc space involvement: type 1 (no involvement); type 2 (involving disc space but not crossing); type 3 (crossing disc space but not fused); and type 4 (complete bridging). Range of motion (ROM) for each segment was measured using dynamic radiographs. Statistical analyses were performed to determine the degree of OPLL progression according to the four disc space involvement types and ROM.

RESULTS

Mean OPLL progression was significantly higher in types 2 (1.3 mm) and 3 (1.5 mm) than in type 1 (0.5 mm) (p<.001). Severe progression (change in thickness >2 mm) was more frequent in types 2 (8 of 29) and 3 (7 of 16) than in types 1 (1 of 35) or 4 (0 of 6) (p=.002). In types 2 or 3, ROM>5° was correlated with severe OPLL progression (52% vs. 8%; p=.035).

CONCLUSIONS

Type 2 or 3 disc involvement and segmental ROM>5° were risk factors for OPLL progression. Classification of cervical OPLL according to disc involvement may help predict OPLL progression following laminoplasty. Close follow-up is warranted in cases of type 2 or 3 with greater segmental motion.

A novel anterior decompression technique (vertebral body sliding osteotomy) for ossification of posterior longitudinal ligament of the cervical spine

BACKGROUND CONTEXT

Conventional anterior decompression surgery for cervical myelopathy, including anterior corpectomy and fusion, is technically demanding and is known to be associated with a higher incidence of surgery-related complications, including cerebrospinal fluid (CSF) leakage, neurologic deterioration, and graft failure compared with posterior surgery.

PURPOSE

We introduce a novel anterior decompression technique (vertebral body sliding osteotomy [VBSO]) for cervical myelopathy caused by ossification of posterior longitudinal ligament (OPLL) and evaluate the efficacy and safety of this procedure.

STUDY DESIGN

This is a case series for novel surgical technique.

PATIENT SAMPLE

Fourteen patients (M:F=11:3, mean age 56.9±10) with cervical myelopathy caused by OPLL who underwent VBSO by a single surgeon were included.

OUTCOME MEASURES

The surgical outcome was evaluated according to the Japanese Orthopaedic Association score for cervical myelopathy (C-JOA score), and the recovery rate of the C-JOA score was calculated. Patients were also evaluated radiographically with plain and dynamic cervical spine radiographs and pre- and postoperative computed tomography images.

METHODS

Fourteen patients were followed up for more than 24 months, and operation time, estimated blood loss, neurologic outcomes, and surgery-related complications were investigated. Radiological measurements were also performed to analyze the following parameters: (1) canal-occupying ratio and postoperative canal widening, and (2) pre- and postoperative sagittal alignment.

RESULTS

The mean recovery rate of C-JOA score at the final follow-up was 68.65±17.8%. There were no perioperative complications, including neurologic deterioration, vertebral artery injury, esophageal injury, graft dislodgement, and CSF leaks, after surgery except for pseudarthrosis in one case. An average spinal canal compromised ratio by OPLL decreased from 61.5±8.1% preoperatively to 16.5±11.2% postoperatively. An average postoperative canal widening was 5.15±1.39 mm, and improvement of cervical alignment was observed in all patients, with average recovery angle of 7.3±6.1° postoperatively.

CONCLUSIONS

The VBSO allows sufficient decompression of spinal cord and provides excellent neurologic outcomes. Because surgeons do not need to manipulate the OPLL mass directly, this technique could significantly decrease surgery-related complications. Furthermore, as VBSO is based on the multilevel discectomy and fusion technique, it would be more helpful to restore a physiological lordosis.

Referral patterns and patient characteristics at the first visit to a scoliosis center: a 2-year experience in South Korea without a school scoliosis-screening program

OBJECTIVE The need for scoliosis screening remains controversial. Nationwide school screening for scoliosis has not been performed in South Korea, and there are few studies on the referral patterns of patients suspected of having scoliosis. This study aimed to examine the referral patterns to the largest scoliosis center in South Korea in the absence of a school screening program and to analyze the factors that influence the appropriateness of referral. METHODS The medical records of patients who visited a single scoliosis center for a spinal deformity evaluation were reviewed. Among 1895 new patients who visited this scoliosis center between April 2014 and March 2016, 1211 with presumed adolescent idiopathic scoliosis were included in the study. Patients were classified into 4 groups according to the referral method: non-health care provider, primary physician, hospital specialist, or school screening program. The appropriateness of referral was labeled as inappropriate, late, or appropriate. In total, 213 of 1211 patients were excluded because they had received treatment at another medical facility; 998 patients were evaluated to determine the appropriateness of referral. RESULTS Of the 998 referrals of new patients with presumed adolescent idiopathic scoliosis, 162 (16.2%) were classified as an inappropriate referral, 272 (27.3%) were classified as a late referral, and 564 (56.5%) were classified as an appropriate referral. Age, sex, Cobb angle of the major curve, and skeletal maturity were identified as statistically significant factors that correlated with the appropriateness of referral. The referral method did not correlate with the appropriateness of referral. CONCLUSIONS Under the current health care system in South Korea, a substantial number of patients with presumed adolescent idiopathic scoliosis are referred either late or inappropriately to a tertiary medical center. Although patients referred by school screening programs had a significantly lower late referral rate and higher appropriate referral rate than the other 3 groups, the referral method was not a significant factor in terms of the appropriateness of referral.

Multilevel posterior foraminotomy with laminoplasty versus laminoplasty alone for cervical spondylotic myelopathy with radiculopathy: a comparative study

BACKGROUND CONTEXT

Conventional laminoplasty is useful for expanding a stenotic spinal canal. However, it has limited use for the decompression of accompanying neural foraminal stenosis. As such, an additional posterior foraminotomy could be simultaneously applied, although this procedure carries a risk of segmental kyphosis and instability.

PURPOSE

The aim of this study was to elucidate the long-term surgical outcomes of additional posterior foraminotomy with laminoplasty (LF) for cervical spondylotic myelopathy (CSM) with radiculopathy.

STUDY DESIGN/SETTING

A retrospective comparative study was carried out.

PATIENT SAMPLE

Ninety-eight consecutive patients who underwent laminoplasty for CSM with radiculopathy between January 2006 and December 2012 were screened for eligibility. This study included 66 patients, who were treated with a laminoplasty of two or more levels and followed up for more than 2 years after surgery.

OUTCOME MEASURES

The Neck Disability Index (NDI), Japanese Orthopedic Association (JOA) scores, JOA recovery rates, and visual analog scale (VAS) were used to evaluate clinical outcomes. The C2-C7 sagittal vertical axis distance, cervical lordosis, range of motion (ROM), and angulation and vertebral slippage at the foraminotomy level were used to measure radiological outcomes using the whole spine anterioposterior or lateral and dynamic lateral radiographs.

METHODS

Sixty-six patients with CSM with radiculopathy involving two or more levels were consecutively treated with laminoplasty and followed up for more than 2 years after surgery. The first 26 patients underwent laminoplasty alone (LA group), whereas the next 40 patients underwent an additional posterior foraminotomy at stenotic neural foramens with radiating symptoms in addition to laminoplasty (LF group). In the LF group, the foraminotomy with less resection than 50% of facet joint to avoid segmental kyphosis and instability was performed at 78 segments (unilateral-to-bilateral ratio=57:21) and 99 sites. Clinical and radiographic data were assessed preoperatively and at 2-year follow-up and compared between the groups.

RESULTS

The NDI, JOA scores, JOA recovery rates, and VAS for neck and arm pain were improved significantly in both groups after surgery. The improvement in the VAS for arm pain was significantly greater in the LF group (from 5.55±2.52 to 1.85±2.39) than the LA group (from 5.48±2.42 to 3.40±2.68) (p<.001). Although cervical lordosis and ROM decreased postoperatively in both groups, there were no significant differences in the degree of reduction between the LF and LA groups. Although the postoperative focal angulation and slippage were slightly increased in the LF group, this was not to a significant degree. Furthermore, segmental kyphosis and instability were not observed in the LF group, regardless of whether the patient underwent a unilateral or bilateral foraminotomy.

CONCLUSIONS

Additional posterior foraminotomy with laminoplasty is likely to improve arm pain more significantly than laminoplasty alone by decompressing nerve roots. Also, performing posterior foraminotomy via multiple levels or bilaterally did not significantly affect segmental malalignment and instability. Therefore, when a laminoplasty is performed for CSM with radiculopathy, an additional posterior foraminotomy could be an efficient and safe treatment that improves both myelopathy symptoms and radicular arm pain.

Cervical sagittal alignment in patients with adolescent idiopathic scoliosis: is it corrected by surgery?

OBJECTIVE Cervical sagittal alignment (CSA) is related to function and quality of life, but it has not been frequently studied in patients with adolescent idiopathic scoliosis. This study aimed to reveal the change in CSA following corrective surgery, compare the cervical sagittal parameters according to curve types, and assess related factors for postoperative aggravation of CSA. METHODS The authors studied 318 consecutive patients with adolescent idiopathic scoliosis who underwent corrective surgery at a single center. Occiput-C2 and C2-7 lordosis, C2-7 sagittal vertical axis (SVA), T-1 slope, thoracic kyphosis, and lumbar sagittal profiles were measured preoperatively and postoperatively. Scoliosis Research Society Outcomes Questionnaire (SRS-22) scores were used as clinical outcomes. Each radiological parameter was compared preoperatively and postoperatively according to curve types (double major, single thoracic, and double thoracic curves). Patients were grouped based on preoperative CSA: the lordotic group (group L) and the kyphotic group (group K). Each radiological parameter was compared between the groups. Related factors for postoperative aggravation of CSA were assessed using multivariate logistic analysis. RESULTS Of the total number of patients studied, 67.0% (213 of 318) and 54.4% (173 of 318) showed cervical kyphotic alignment preoperatively and postoperatively, respectively. C2-7 lordosis increased (from -5.8° to -1.1°; p < 0.001) and C2-7 SVA decreased (from 24.2 to 20.0 mm; p < 0.001) postoperatively regardless of curve types. Although group K showed improvement in C2-7 lordosis (from -12.7° to -4.8°; p < 0.001), group L showed no difference (from 9.0° to 6.9°; p = 0.115) postoperatively. Clinical outcomes were not related to the degree of cervical kyphosis in this cohort. C2-7 lordosis (p < 0.001) and pelvic tilt (p = 0.019) were related to postoperative aggravation of CSA. CONCLUSIONS Regardless of the trend of improvement in CSA, many patients (54.4%) still showed cervical kyphotic alignment postoperatively. C2-7 lordosis and C2-7 SVA improved postoperatively in all curve types. However, postoperative changes in C2-7 lordosis showed different results based on preoperative CSA, which could be related to T-1 slope and thoracic kyphosis. However, clinical outcomes showed no difference based on CSA in this study cohort. Greater C2-7 lordosis and proximal thoracic curve preoperatively were risk factors for postoperative aggravation of CSA (p < 0.001 and p = 0.019, respectively).

Analgesic Efficacy and Safety of Prolonged-Release Oxycodone/Naloxone in Korean Patients with Chronic Pain from Spinal Disorders

Background

A prolonged-release formulation of oxycodone/naloxone has been shown to be effective in European populations for the management of chronic moderate to severe pain. However, no clinical data exist for its use in Korean patients. The objective of this study was to assess efficacy and safety of prolonged-release oxycodone/naloxone in Korean patients for management of chronic moderate-to-severe pain.

Methods

In this multicenter, single-arm, open-label, phase IV study, Korean adults with moderate-to-severe spinal disorder-related pain that was not satisfactorily controlled with weak opioids and nonsteroidal anti-inflammatory drugs received prolonged-release oral oxycodone/naloxone at a starting dose of 10/5 mg/day (maximum 80/40 mg/day) for 8 weeks. Changes in pain intensity and quality of life (QoL) were measured using a numeric rating scale (NRS, 0–10) and the Korean-language EuroQol-five dimensions questionnaire, respectively.

Results

Among 209 patients assessed for efficacy, the mean NRS pain score was reduced by 25.9% between baseline and week 8 of treatment (p < 0.0001). There was also a significant improvement in QoL from baseline to week 8 (p < 0.0001). The incidence of adverse drug reactions was 27.7%, the most common being nausea, constipation, and dizziness; 77.9% of these adverse drug reactions had resolved or were resolving at the end of the study.

Conclusions

Prolonged-release oxycodone/naloxone provided significant and clinically relevant reductions in pain intensity and improved QoL in Korean patients with chronic spinal disorders. (ClinicalTrials.gov identifier: NCT01811238)

Effect of one- or two-level posterior lumbar interbody fusion on global sagittal balance

BACKGROUND CONTEXT

Sagittal imbalance is associated with poor clinical outcomes in patients with degenerative lumbar disease. However, there is no consensus on the impact of posterior lumbar interbody fusion (PLIF) on local and global sagittal balance.

PURPOSE

To reveal the effect of one- or two-level PLIF on global sagittal balance.

DESIGN/SETTING

A retrospective case-control study.

PATIENTS SAMPLE

This study included 88 patients who underwent a one- or two-level PLIF for spinal stenosis with spondylolisthesis.

OUTCOME MEASURES

Clinical and radiological parameters were measured pre- and postoperatively.

METHODS

All patients were followed up for >2 years. Clinical outcomes included a visual analog scale, Oswestry Disability Index, and EuroQol 5-dimension questionnaire (EQ-5D). Radiological parameters were measured using whole-spine standing lateral radiographs. Fusion, loosening, subsidence rates, and adverse events were also evaluated. Patients were divided into two groups according to their preoperative C7-S1 sagittal vertical axis (SVA): Group N: SVA≤5 cm vs Group I: SVA>5 cm; they were also divided according to postoperative changes in C7-S1 SVA. Clinical and radiological outcomes were compared between the groups.

RESULTS

All clinical outcomes and radiological parameters improved postoperatively. C7-S1 SVA improved (-1.6 cm) after L3-L5 fusion, but it was compromised (+3.6 cm) after L4-S1 fusion (p=.001). Preoperative demographic and clinical data showed no difference except in the anxiety or depression domain of EQ-5D. No differences were found in postoperative clinical outcomes. Lumbar lordosis, pelvic tilt, and thoracic kyphosis slightly improved in Group N, whereas C7-S1 SVA decreased from 9.5 cm to 3.8 cm (p<.001) in Group I. Furthermore, all sagittal parameters improved in Group I. On comparing the postoperative changes in C7-S1 SVA, we found that the decreasing trend in the postoperative C7-S1 SVA was related to a larger preoperative C7-S1 SVA (p=.030) and a more proximal level fusion (L3-L5 vs L4-S1, p=.033).

CONCLUSIONS

Global sagittal balance improved after short-level lumbar fusion surgery in patients having spinal stenosis with spondylolisthesis who showed preoperative sagittal imbalance. Restoration of sagittal balance predominantly occurred after L3-L4, L4-L5, or L3-L5 PLIF. However, no such restoration was observed after L5-S1 or L4-S1 PLIF. Thus, we could anticipate sagittal balance restoration after performing PLIF at L3-L4 or L4-L5 level. However, caution is required when planning for L5-S1 fusion if preoperative sagittal imbalance is present.

Efficacy of Escherichia coli-derived recombinant human bone morphogenetic protein-2 in posterolateral lumbar fusion: an open, active-controlled, randomized, multicenter trial

BACKGROUND CONTEXT

The efficacy and safety of recombinant human bone morphogenetic protein-2 (rhBMP-2) as a bone graft substitute in spinal fusion has been widely researched. However, no study of the efficacy and safety of Escherichia coli-derived rhBMP-2 (E.BMP-2) with a hydroxyapatite (HA) carrier has been proposed.

PURPOSE

This study aimed to compare the efficacy and safety of fusion materials between E.BMP-2 and autogenous iliac bone graft in posterolateral fusion (PLF).

STUDY DESIGN/SETTING

An open, active-controlled, randomized, multicenter trial was carried out.

PATIENT SAMPLE

This study included 93 patients who underwent single-level lumbar or lumbosacral PLF.

OUTCOME MEASURES

The primary outcome measure was computed tomography (CT)-based fusion rate at 12 and 24 weeks. Secondary outcome measures were fusion grade by radiographs and CT at 12 and 24 weeks and changes in Oswestry Disability Index (ODI), Short Form-36 (SF-36) Health Survey, and visual analogue scale (VAS).

METHODS

Patients who underwent 1-level PLF (between L1 and S1) for severe spinal stenosis or grade 1 spondylolisthesis were randomized to receive E.BMP-2 with an HA carrier (E.BMP-2 group) or autogenous iliac bone graft (AIBG group). Thin-section CT (<2 mm), VAS, ODI, and SF-36 were obtained pre- and postoperatively at 12 and 24 weeks. Outcome measures were compared between the groups.

RESULTS

A total of 100 patients were enrolled in this trial. Among them, 93 patients underwent planned surgery. Preoperative demographic and clinical data showed no difference between groups. CT-based fusion rates were 100.0% (41/41) for the E.BMP-2 group and 90.2% (46/51) for the AIBG group (p=.062) at 12 weeks and 100.0% (41/41) and 94.1% (48/51) (p=.251) at 24 weeks, respectively. Fusion grade based on radiographs and CT showed non-inferiority of the E.BMP-2 group compared with the AIBG group. All clinical parameters improved postoperatively. However, there was no difference in changes in VAS, ODI, or SF-36 between the groups. No serious adverse event related to E.BMP-2 was found.

CONCLUSIONS

The fusion rate of E.BMP-2 was comparable with that of AIBG following PLF. Good clinical efficacy and safety of E.BMP-2 in spinal fusion were also revealed. It was also suggested that HA shows suitability as a carrier for E.BMP-2. Thus, E.BMP-2 with an HA carrier can be an alternative bone graft material in spinal fusion.

Progression of trunk imbalance in adolescent idiopathic scoliosis with a thoracolumbar/lumbar curve: is it predictable at the initial visit?

OBJECTIVE Progression of trunk imbalance is an important finding during follow-up of patients with adolescent idiopathic scoliosis (AIS). Nevertheless, no factors that predict progression of trunk imbalance have been identified. The purpose of this study was to identify parameters that predict progression of trunk imbalance in cases of AIS with a structural thoracolumbar/lumbar (TL/L) curve. METHODS This study included 105 patients with AIS and a structural TL/L curve who were followed up at an outpatient clinic. Patients with trunk imbalance (trunk shift ≥ 20 mm) at the initial visit were excluded. All patients were followed up for more than 2 years. Patients were divided into the following groups according to progression of trunk imbalance: 1) Group P, trunk shift ≥ 20 mm at the final visit and degree of progression ≥ 10 mm; and 2) Group NP, trunk shift < 20 mm at the final visit or degree of progression < 10 mm. Radiological parameters included Cobb angle, upper end vertebrae and lower end vertebrae (LEV), LEV tilt, disc wedge angle between LEV and LEV+1, trunk shift, apical vertebral translation, and apical vertebral rotation (AVR). Each parameter was compared between groups. Radiological parameters were assessed at every visit using whole-spine standing anteroposterior radiographs. RESULTS Among the 105 patients examined, 13 showed trunk imbalance with progression ≥ 10 mm at the final visit (Group P). Multivariate logistic regression analysis identified a lower Risser grade (p = 0.002) and a greater initial AVR (p = 0.020) as predictors of progressive trunk imbalance. A change in LEV tilt during follow-up was associated with trunk imbalance (p = 0.001). CONCLUSIONS Risser grade and AVR measured at the initial visit may predict progression of trunk imbalance. Surgeons should consider the risk of progressive trunk imbalance if patients show skeletal immaturity and a greater AVR at the initial visit.

Five major controversial issues about fusion level selection in corrective surgery for adolescent idiopathic scoliosis: a narrative review

BACKGROUND CONTEXT

Shoulder imbalance, coronal decompensation, and adding-on phenomenon following corrective surgery in patients with adolescent idiopathic scoliosis are known to be related to the fusion level selected. Although many studies have assessed the appropriate selection of the proximal and distal fusion level, no definite conclusions have been drawn thus far.

PURPOSE

We aimed to assess the problems with fusion level selection for corrective surgery in patients with adolescent idiopathic scoliosis, and to enhance understanding about these problems.

STUDY DESIGN

This study is a narrative review.

METHODS

We conducted a literature search of fusion level selection in corrective surgery for adolescent idiopathic scoliosis. Accordingly, we selected and reviewed five debatable topics related to fusion level selection: (1) selective thoracic fusion; (2) selective thoracolumbar-lumbar (TL-L) fusion; (3) adding-on phenomenon; (4) distal fusion level selection for major TL-L curves; and (5) proximal fusion level selection and shoulder imbalance.

RESULTS

Selective fusion can be chosen in specific curve types, although there is a risk of coronal decompensation or adding-on phenomenon. Generally, wider indications for selective fusions are usually associated with more frequent complications. Despite the determination of several indications for selective fusion to avoid such complications, no clear guidelines have been established. Although authors have suggested various criteria to prevent the adding-on phenomenon, no consensus has been reached on the appropriate selection of lower instrumented vertebra. The fusion level selection for major TL-L curves primarily focuses on whether distal fusion can terminate at L3, a topic that remains unclear. Furthermore, because of the presence of several related factors and complications, proximal level selection and shoulder imbalance has been constantly debated and remains controversial from its etiology to its prevention.

CONCLUSIONS

Although several difficult problems in the diagnosis and treatment of adolescent idiopathic scoliosis have been resolved by understanding its mechanism and via technical advancement, no definite guideline for fusion level selection has been established. A review of five major controversial issues about fusion level selection could provide better understanding of adolescent idiopathic scoliosis. We believe that a thorough validation study of the abovementioned controversial issues can help address them.

A novel technique to correct kyphosis in cervical myelopathy due to continuous-type ossification of the posterior longitudinal ligament

OBJECTIVE

Although posterior decompressive surgery is widely used to treat patients with cervical myelopathy and multilevel ossification of the posterior longitudinal ligament (OPLL), a poor outcome is anticipated if the sagittal alignment is kyphotic (or K-line negative). Accordingly, it is mandatory to perform anterior decompression and fusion in patients with cervical kyphosis. However, it can be difficult to perform anterior surgery because of the high risk of complications. This present report proposes a novel “greenstick fracture technique” to change the K-line from negative to positive in patients with cervical myelopathy, OPLL, and kyphotic deformity.

METHODS

Four patients with cervical myelopathy, continuous-type OPLL, and kyphotic sagittal alignment (who were K-line negative) were indicated for surgery. Posterior laminectomy and lateral mass screw insertions using a posterior approach were performed, followed by anterior surgery. Multilevel discectomy and thinning of the OPLL mass by bur drilling was performed, then an intentional greenstick fracture at each disc level was made to convert the cervical K-line from negative to positive. Finally, posterior instrumentation using a rod was carried out to maintain cervical lordosis.

RESULTS

MRI showed complete decompression of the cord by posterior migration in all cases, which had been caused by cervical lordosis. Restoration of neurological defects was confirmed at the 1-year follow-up assessment. No specific complications were identified that were associated with this technique.

CONCLUSIONS

A greenstick fracture technique may be effective and safe when applied to patients with cervical myelopathy, continuous-type OPLL, and kyphotic deformity (K-line negative). However, further studies with more cases will be required to reveal its generalizability and safety.

Preoperative embolization in patients with metastatic spinal cord compression: mandatory or optional?

Background

The contribution of preoperative embolization in reducing intraoperative blood loss and its clinical importance are unclear. So, we aimed to compare the perioperative clinical outcomes based on whether preoperative embolization was performed and assess the role and safety of preoperative embolization in metastatic spinal cord compression (MSCC) patients.

Methods

We enrolled 52 patients (men, 37; women, 15) who underwent palliative decompression for MSCC. Demographic data, neurologic status, surgery-related data (operation time, estimated blood loss, and transfusion), complications, and survival time were recorded. Patients were categorized based on whether they received preoperative embolization: groups E (embolization) (n = 18) and NE (non-embolization) (n = 34) and the clinical parameters were compared. Subgroup analysis was performed specifically for cases of hypervascular tumors (23/52, 44%).

Results

The transfusion degree was greater in the NE group (4.6 pints) than in the E group (2.5 pints, P = 0.025); the other parameters did not differ between the groups. However, massive bleeding (>2000 mL) was more frequent in the NE group (10/34) than in the E group (0/18, P = 0.010). Subgroup analysis indicated that intraoperative blood loss was greater in the NE group (1988 mL) than in the E group (1095 mL, P = 0.042) in hypervascular tumor patients. Although massive bleeding was more frequent among hypervascular tumor patients, 3 patients with non-hypervascularized tumors also exhibited massive bleeding (P = 0.087).

Conclusions

Intraoperative blood loss and perioperative transfusion can be reduced by preoperative embolization in MSCC patients. Neurologic recovery, operation time, and complications did not differ according to the application of embolization. As preoperative embolization is relatively safe and effective for controlling intraoperative bleeding without any neurologic deterioration, it is highly recommended for hypervascular tumors. Moreover, it may also be effective for non-hypervascular tumors as massive bleeding may be noted in some cases.

Association between Sacral Slanting and Adjacent Structures in Patients with Adolescent Idiopathic Scoliosis

Background

Sacral slanting is a frequent unique phenomenon in patients with adolescent idiopathic scoliosis (AIS) and may be important for selecting the distal fusion level. However, the reason of the phenomenon remains unknown. The purpose of this study was to determine the association between sacral slanting and adjacent structures in patients with AIS.

Methods

A total of 303 AIS patients who underwent both whole spine standing anteroposterior (AP) and whole leg standing AP radiography were included. The degree of sacral slanting, pelvic obliquity, lumbar curve angles (L1-L4), and L4 tilt were assessed on whole spine standing AP radiographs. Whole leg standing AP radiographs were used to assess the degree of leg length discrepancy (LLD). Demographic data and radiological parameters were analyzed descriptively. Pearson correlation analysis and partial correlation analysis of the parameters were performed. A p-value of less than 0.05 was considered statistically significant.

Results

The proportion of patients with ≥ 5° of sacral slanting among those with < 3° of pelvic obliquity was 8.9% (27/303). Thirty-two patients (10.6%, 32/303) showed more than 10 mm of LLD. Sacral slanting was positively correlated with pelvic obliquity and lumbar curve (r = 0.445 and r = 0.325, respectively). Pelvic obliquity was also correlated with LLD and L4 tilt (r = 0.123 and r = 0.311, respectively). However, partial correlation analysis showed that LLD was not directly correlated with sacral slanting (r = −0.034).

Conclusions

Sacral slanting can be thought to be a compensatory mechanism for large lumbar curves, which is accompanied by pelvic obliquity. In contrast, a congenitally slanted upper sacrum may contribute to scoliosis in some cases. LLD was not directly correlated with sacral slanting.

A CT-Based Simulation Study to Compare the Risk of Facet Joint Violation by the Cervical Pedicle Screw Between Degenerative and Nondegenerative Cervical Spines

STUDY DESIGN

A retrospective case-control study.

OBJECTIVE

This study aimed (A) to compare entry points and trajectories of the cervical pedicle screw (CPS) between degenerative and nondegenerative spines, and (B) to evaluate the risk of facet joint violation by the CPS according to the degree of facet degeneration.

SUMMARY OF BACKGROUND DATA

Entry point, trajectories, and risk of misplacement of the CPS have been widely researched; however, its application to degenerative cervical spine has to be elucidated.

METHODS

Sixty patients who underwent cervical surgeries at our institution were classified into two groups according to cervical facet joint degeneration. A simulation program with 0.7-mm thickness axial computed tomographic images was used to evaluate facet joint violation by the CPS from C3 to C6. Horizontal and vertical offsets of entry points were measured from two different anatomical landmarks on lateral mass, namely the lateral notch and the center of the superior ridge. The transverse and sagittal angles of the screws were also measured. Facet joint violation was evaluated and classified into either "minor" (<50% of screw diameter) or "major" (≥50% of screw diameter).

RESULTS

The mean transverse and sagittal angles showed no difference between the two groups. However, a more superior vertical offset from the superior ridge in terms of entry point was observed in the degenerative cervical spine group at all levels (P = 0.001-0.026). In addition, facet joint violation was more frequently found in severely degenerated facet joints than in mild to moderately degenerated facet joints (P = 0.011).

CONCLUSION

The entry point of CPS was moved more superiorly in the degenerative cervical spine in this study, which increased the risk of facet joint violation in our patients. Thus, surgeons need to modify the insertion technique of the CPS or to insert lateral mass screw instead of the CPS when it is considered to insert screws at the uppermost vertebra in the degenerative cervical spine.

LEVEL OF EVIDENCE

4.

Treatment Outcomes for Patients with Failed Back Surgery

BACKGROUND

Failed back surgery syndrome (FBSS) is a frequently encountered disease entity following lumbar spinal surgery. Although many plausible reasons have been investigated, the exact pathophysiology remains unknown. Various medications, reoperations, interventions such as spinal cord stimulation, epidural adhesiolysis or epidural injection, exercise therapy, and psychotherapy have been suggested treatment options. However, the evidence of the clinical outcome for each treatment has not been clearly determined.

OBJECTIVES

To evaluate the outcomes of each treatment modality and to present treatment guidelines for patients with FBSS.

STUDY DESIGN

A systematic review of each treatment regimen in patients with FBSS.

METHODS

The available literature regarding each modality for the treatment of refractory back pain or radiating pain for FBSS was reviewed. The quality assessment and the level of evidence were analyzed using the "Methodology Checklist" of SIGN (Scottish Intercollegiate Guidelines Network). Data sources included relevant English language literature identified through searches of Pubmed, EMBASE, and Cochrane library from 1980 to Feb 2016. The primary outcome measure was pain relief of back pain or radiating pain for at least 3 months. Secondary outcome measures were improvement of the patient's functional status, health-related quality of life, return to work, and reduction of opioid use.

RESULTS

Twenty-three articles were finally identified and reviewed. Based on our analysis, epidural adhesiolysis showed a short-term (6 to 24 months) effect (grade A) and spinal cord stimulation showed a mid-term (2 or 3 years) effect (grade B). Epidural injections showed a short-term (up to 2 years) effect (grade C). However, other treatments were recommended as grade D or inconclusive.

LIMITATIONS

The limitations of this systematic review included the rarity of relevant literature.

CONCLUSIONS

Epidural adhesiolysis or spinal cord stimulation can be effective in order to control chronic back pain or leg pain due to FBSS, and its recommendation grades are A and B, respectively. Other treatments showed poor or inconclusive evidence.Key words: Failed back surgery syndrome, post spinal surgery syndrome, chronic low back pain, post lumbar surgery syndrome, epidural adhesiolysis, spinal cord stimulation, epidural injection, revision.

A retrospective study to reveal factors associated with postoperative shoulder imbalance in patients with adolescent idiopathic scoliosis with double thoracic curve

OBJECTIVE Postoperative shoulder imbalance (PSI) is a critical consideration after corrective surgery for a double thoracic curve (Lenke Type 2); however, the radiographic factors related to PSI remain unclear. The purpose of this study was to identify the radiographic factors related to PSI after corrective surgery for adolescent idiopathic scoliosis (AIS) in patients with a double thoracic curve. METHODS This study included 80 patients with Lenke Type 2 AIS who underwent corrective surgery. Patients were grouped according to the presence [PSI(+)] or absence [PSI(-)] of shoulder imbalance at the final follow-up examination (differences of 20, 15, and 10 mm were used). Various radiographic parameters, including the Cobb angle of the proximal and middle thoracic curves (PTC and MTC), radiographic shoulder height (RSH), clavicle angle, T-1 tilt, trunk shift, and proximal and distal wedge angles (PWA and DWA), were assessed before and after surgery and compared between groups. RESULTS Overall, postoperative RSH decreased with time in the PSI(-) group but not in the PSI(+) group. Statistical analyses revealed that the preoperative Risser grade (p = 0.048), postoperative PWA (p = 0.028), and postoperative PTC/MTC ratio (p = 0.011) correlated with PSI. Presence of the adding-on phenomenon was also correlated with PSI, although this result was not statistically significant (p = 0.089). CONCLUSIONS Postoperative shoulder imbalance is common after corrective surgery for Lenke Type 2 AIS and correlates with a higher Risser grade, a larger postoperative PWA, and a higher postoperative PTC/MTC ratio. Presence of the distal adding-on phenomenon is associated with an increased PSI trend, although this result was not statistically significant. However, preoperative factors other than the Risser grade that affect the development of PSI were not identified by the study. Additional studies are required to reveal the risk factors for the development of PSI.

Patterns of Treatment for Metastatic Pathological Fractures of the Spine: The Efficacy of Each Treatment Modality

BACKGROUND

Metastatic pathological fractures of the spine are a major problem for cancer patients; however, there is no consensus on treatment strategy. The purpose of this study was to evaluate various treatment options by analyzing their patterns for metastatic pathological fractures of the spine.

METHODS

In this study, 54 patients (male:female = 36:18) who were diagnosed with metastatic pathological fractures of spine were recruited. Demographic data, origin of cancer, type of treatment, and results were obtained from electronic medical records. Treatment options were divided into radiotherapy (RT), vertebroplasty (VP) or kyphoplasty (KP), operation (OP), and other treatments. Treatment results were defined as aggravation, no response, fair response, good response, and unknown. The survival time after detection of pathologic fractures was analyzed with the Kaplan-Meier method.

RESULTS

The mean age of the patients was 62.3 years. Hepatocellular carcinoma was the most common cancer of primary origin (n = 9), followed by multiple myeloma (n = 8). RT was the most common primary choice of treatment (n = 29, 53.7%), followed by OP (n = 13, 24.1%), and VP or KP (n = 10, 18.5%). Only 13 of 29 RT cases and 7 of 13 OP cases demonstrated a fair or good response. The mean survival time following detection of pathological spinal fractures was 11.1 months for 29 patients, who died during the study period.

CONCLUSIONS

RT was the most common primary choice of treatment for metastatic pathological fractures of the spine. However, the response rate was suboptimal. Although OP should be considered for the relief of mechanical back pain or neurologic symptoms, care should be taken in determining the surgical indication. VP or KP could be considered for short-term control of localized pain, although the number of cases was too small to confirm the conclusion. It is difficult to determine the superiority of the treatment modalities, hence, a common guideline for the diagnosis and treatment of metastatic pathological fractures of the spine is required.

The clinical importance of sacral slanting in patients with adolescent idiopathic scoliosis undergoing surgery

BACKGROUND CONTEXT

The phenomenon of sacral slanting has not been assessed in patients with adolescent idiopathic scoliosis (AIS). It could be important in determining distal fusion level.

PURPOSE

The purpose of this study is to clarify sacral slanting and to reveal frequency, character, and clinical importance of sacral slanting in AIS patients who underwent surgery.

STUDY DESIGN/SETTING

Retrospective review of radiographs.

PATIENT SAMPLE

The study included 389 patients who underwent surgery for AIS at a single center.

OUTCOME MEASURES

Slanted angles of sacrum, distal curve types, and postoperative decompensation were assessed in whole spine anteroposterior radiographs.

METHODS

This was a retrospective case series, which included 389 AIS patients who underwent corrective surgeries. The degree of sacral slanting was defined as the angle between the horizontal line and the upper end plate of the sacrum. Distal curves were classified according to the direction of L4 tilt (L4-left type and L4-right type). The frequency, direction, and relationship with curve types were analyzed descriptively. Postoperative changes of sacral slanting were compared by paired t test. Decompensation by distal fusion level and distal curve types was analyzed descriptively. The p value of less than .05 was considered as statistically significant.

RESULTS

The frequency of sacral slanting was 19.5% (76 of 389), 29.6% (115 of 389), and 40.6% (158 of 389) by using criteria of 5°, 4°, and 3°, respectively. The 86.7% showed sacral slanting on the left side. The combination of L4-left type with left-sided sacral slanting was the most frequent (124 of 158, 78.7%). Slanted angles were decreased in some cases after surgery. Decompensation in the coronal plane was observed in 2 of 22 patients (9.1%) with a distal fusion level of L4 but in none of the 70 patients with a distal fusion level of L3.

CONCLUSIONS

Sacral slanting in patients with AIS is a unique and frequently observed finding that has never been researched to date. Most importantly, sacral slanting is a critical consideration in selecting distal fusion level when planning corrective surgery in patients with AIS.

Feasibility of correction with instrumentation only in congenital scoliosis

BACKGROUND

Although effective correction of deformity in congenital scoliosis can often be achieved with instrumentation only and without more invasive techniques such as hemivertebrectomy (HV), reports of the feasibility of correction with instrumentation only (IO) are lacking.

OBJECTIVE

To compare the results of deformity correction using IO vs HV and to examine the feasibility of and indications for correction with IO in patients with congenital scoliosis.

METHODS

Twenty-five patients underwent correction with either IO (n = 14) or HV (n = 11). The 2 patient groups were compared in terms of age at the time of surgery, preoperative magnitude and flexibility of the main curve, correction rates after surgery and at the final follow-up, surgery time, estimated blood loss, and complications.

RESULTS

The 2 groups did not differ significantly in terms of average patient age or curve magnitude, but the correction with the IO group had greater preoperative curve flexibility (37.1%) than the HV group (21.0%). The correction rates immediately after surgery were high in both groups. The correction with IO group had a shorter mean operation time (308 minutes vs 366 minutes) and less blood loss (540 mL vs 1547 mL) than the HV group.

CONCLUSION

Satisfactory correction of congenital scoliosis can be obtained with IO if there is adequate flexibility in the main curve, thus avoiding the need for more invasive procedures such as HV.

Effects of transforaminal balloon treatment in patients with lumbar foraminal stenosis: a randomized, controlled, double-blind trial

BACKGROUND

Lumbar spinal stenosis is a common condition in the elderly. Although balloon treatment is a well-known therapeutic method in specific pain conditions, applying the balloon treatment in patients with lumbar spinal stenosis is not yet well established.

OBJECTIVES

We tested the therapeutic effect of transforaminal balloon treatment with a Fogarty balloon catheter on body pain and functional performance in patients with severe lumbar spinal stenosis.

STUDY DESIGN

Prospective, randomized, double-blinded, active control trial.

SETTING

A tertiary, interventional pain management practice, specialty referral center.

METHODS

Sixty-two patients with refractory unilateral radiculopathy aggravated by walking were enrolled and randomly assigned to receive transforaminal steroid injection after transforaminal balloon treatment using a 3 Fr balloon catheter (n = 32) or the same procedure without balloon treatment (n = 30). The patients were prohibited from making any alterations to their medications during the 12 weeks of their follow-up period. After the first 12 weeks, the patients who had persistent symptoms or unbearable pain were allowed to increase the dose of analgesics or to receive additional interventional treatment.

OUTCOME ASSESSMENT

Visual analogue scale (VAS) pain scores for the leg and lower back, Oswestry disability index (ODI), and claudication distance were measured at 2, 4, 8, and 12 weeks post procedure. During the 52 weeks of the overall follow-up period, the patients achieving ≥ 50% leg pain relief without additional treatment or increasing the dose of analgesics were evaluated.

RESULTS

Significant improvement occurred compared to baseline in VAS (P < 0.001), ODI (P < 0.001), and claudication distance (P < 0.001) in the balloon group during the overall follow-up period, whereas the improvement in ODI (P < 0.05) and claudication distance (P < 0.05) in the control group persisted for 8 weeks. The balloon group showed better improvement in leg VAS (P < 0.05), ODI (P < 0.05), and claudication distance (P < 0.05) than the control group at all post-procedure assessment points. Kaplan-Meier analysis of the duration of the patients achieving ≥ 50% leg pain relief without additional treatment or increasing the dose of analgesics showed a significant intergroup difference between the balloon and control (P = 0.003) groups. Six patients (18.8%) in balloon group maintained ≥ 50% pain relief for 52 weeks whereas no patient (0%) did in control group.

LIMITATIONS

Our study is an active-controlled randomized design with a relatively small number of patients.

CONCLUSION

Transforaminal balloon treatment leads to both significant pain relief and functional improvement in a subset of patients with refractory spinal stenosis. INSTITUTIONAL REVIEW: This study was approved by the Institutional Review Board of the Asan Medical Center.

Direct Repair of the Pars Interarticularis Defect in Spondylolysis

STUDY DESIGN:: This is a retrospective study analyzing the results of Buck's operation for spondylolysis. OBJECTIVE:: To analyze the results of Buck's method as a treatment for symptomatic spondylolysis clinically and radiographically. And propose a new classification system of spondylolysis. SUMMARY OF BACKGROUND DATA:: 50 defects of 25 patients was classified into 4 subtypes and the bone fusion rate of each subgroups was analyzed. MATERIALS AND METHODS:: From March 1992 to March 2008, 50 defects of 25 patients with symptomatic spondylolysis were treated with Buck's method of direct repair. Surgical indication was (1) under 30 years of age, (2) with intractable low back pain without sciatica who did not response to conservative treatment for over 6 months, (3) without disc degeneration in lumbar MRI, (4) without instability in lateral flexion-extension view. Twenty males and five females with an average age of 21.2 years were followed up for an average 5 years 1 month. Clinical assessment using the Kirkaldy-Willis Criteria and radiographic assessment using the simple radiography and bone SPECT were performed. The pars interarticularis defects were classified into 4 subtypes in accordance with radiographical and intraoperative findings. RESULTS:: Clinically, there were 13 "Excellent", 9 "Good", 1 "Fair", and 2 "Poor" cases. 22 cases achieved Good to Excellent results. Radiographically, a total of 36 (72%) of the 50 defects showed union. There were no loosening of screws, but two patients showed screw breakages and nonunion postoperatively. There were no cases of postoperative complications except two cases of screw breakages. Pars interarticularis defects were classified into 4 subtypes- simple, atrophic, hypertrophic, and defect (gap) type. CONCLUSIONS:: It is suggested that Buck's operation, one of the method of treatment of spondylolysis is simple and has low complication rates. It is our conclusion that Buck's operation, which is a method of treatment for spondylolysis and mild spondylolisthesis when performed selectively in younger patients, can provide satisfactory results.