Asian Spine Journal最新文献

Study design: A prospective experimental study.

Purpose: This biomechanical in vitro study aimed to examine the extent to which the use of a rod persuader (RP) leads to additional mechanical stress on the screw-rod system and determine its influence on the bony anchoring of primary pedicle screws.

Overview of literature: Degenerative spine diseases and deformities are the most common indications for the stabilization and fusion of spinal segments. The pedicle screw-rod system is considered the gold standard for dorsal stabilization, and an RP is also increasingly being considered to fit the spondylodesis material.

Methods: Ten lumbar spines from body donors were examined. Bisegmental dorsal spinal lumbar interbody fusion of the L3-L5 segments was performed using a pedicle screw-rod system (ROCCIA Multi-LIF Cage; Silony Medical, Germany). In group 1, the titanium rod was inserted without tension, whereas in group 2, the rod was attached to the pedicle screws at the L4 and L5 levels, creating a 5-mm gap. To attach the rod, the RP was used to press the rod into the pedicle screw. The rod was left in place for 30 minutes and then removed.

Results: The rod reduction technique significantly increased the mechanical load on the overall construct measured by strain gauges (p<0.05) and resulted in outright implant failure with pedicle screw pullout in 88.9%.

Conclusions: In cases where the spondylodesis material is not fully attached within the pedicle screw, an RP can be used with extreme caution, particularly in osteoporotic bones, to avoid pedicle screw avulsion and screw anchor failure.

Both anterior and posterior approaches have shown insignificant differences in good clinical outcomes with one over another advantages and disadvantages. This review aimed to provide evidence for the best management of subaxial cervical spine injuries and discuss the clinical outcomes and complications. Clinical studies of anterior versus posterior and anterior versus anterior-posterior (combined) approaches to subaxial cervical spine injury were searched electronically from PubMed, Medline, ScienceDirect, Cochrane Library, and other Internet databases. Clinical improvement, complication rates, and mortality rates showed no significant differences with an odds ratio of 1.09 (95% confidence interval [CI], 0.79-1.49; p=0.61) for the anterior versus posterior approach and an odds ratio of 1.05 (95% CI, 0.35-3.18; p=0.93) for the anterior versus the combined approach. Surgical duration and blood loss were significantly different between the anterior and posterior groups with a mean difference of -42.84 (95% CI, -64.39 to 21.29; p<0.0001); -212.91 (95% CI, -417.60 to 8.22; p=0.04), respectively, whereas the length of hospitalization did not (p=0.16). No difference was found between the groups when compared by clinical improvement and complication rate. Meanwhile, the anterior approach was superior to the posterior approach in terms of surgical duration, blood loss, and hospitalization length.

Study design: A descriptive, quantitative cross-sectional study of the atlantic part (V3) of the vertebral artery (VA).

Purpose: This study aimed to bridge the research gap in the morphometry of the V3 segment of the VA in the South Indian population.

Overview of literature: The microsurgical anatomy of this segment of the VA has been explored in various populations, and a thorough understanding of the anatomy and course of the VA, particularly the V3 segment, is essential to prevent iatrogenic complications. Several computed tomography studies but a few cadaveric studies have explored the V3 segment of the VA in the South Indian population.

Methods: This study examined 40 VAs from 20 embalmed cadavers that were obtained from the voluntary donation program, and Institutional Ethical Clearance was obtained before the study. The length, diameter, and angle of the vertical, horizontal, and exit parts of the V3 segment of the VA were documented after its exposure.

Results: The mean lengths of the right and left VAs on each part were nearly similar, except for the mean length of the horizontal part (right: 38.937 mm, left: 40.237 mm) and total length of the V3 segment (right: 66.870 mm, left: 70.350 mm).

Conclusions: These morphometric parameters are essential to spine surgeons who intend to operate on a small part (vertical, horizontal, or exit part) of the V3 segment of the VA. The mean values of the parameters obtained in this study give average measurements or safe limits to surgeons for safe surgical procedures such as the occipital condyle screw technique and C1 laminectomy.

Study design: Retrospective study of data abstracted from the Diagnosis Procedure Combination (DPC) database.

Purpose: This study aimed to investigate the effects of surgery in the early phase.

Overview of literature: The optimal timing of surgery for cervical fracture dislocation (CFD) remains unclear because only a few clinical studies with approximately 100 patients have been published.

Methods: This study included 4,653 adult patients with a definitive diagnosis of CFD from the DPC database. The database contains nationwide inpatient data collected from >1,000 acute care hospitals in Japan. The DPC database contains information regarding hospitalization, such as diagnosis, treatment, medical history, complications, and hospitalization outcomes. This study identified 460 pairs of patients after one-to-one propensity-score matching (PSM). Treatment outcomes were compared between patients who underwent surgery for CFD within 72 hours (early group) and later (delayed group) after admission. The main outcomes included 30-day mortality, inhospital death, and major complications. The secondary outcomes were improvement in the Barthel index, length of hospital stay, and discharged home rate.

Results: After adjusting for PSM, the early group had a significantly higher 30-day mortality rates than the delayed group (3.0% vs. 0.4%, p=0.006). In the multivariate logistic regression analysis after PSM, the early group was associated with an increased risk of 30-day mortality (odds ratio, 8.05; 95% confidence interval, 2.15-5.26; p=0.007).

Conclusions: This study indicated that early surgery for CFD resulted in increased 30-day mortality.

Study design: A post-hoc analysis of a prospective cohort study.

Purpose: This study aimed to identify factors at the time of injury associated with declining activities of daily living (ADLs) in the chronic phase of osteoporotic vertebral fractures (OVFs) managed conservatively.

Overview of literature: Although a conservative approach is the treatment of choice for OVFs, ADLs do not improve or eventually decrease in some cases. However, the risk factors for ADL decline after the occurrence of OVFs, particularly the difference between those with or without initial bed rest, are unknown.

Methods: A total of 224 consecutive patients with OVFs aged ≥65 years who received treatment within 2 weeks after the occurrence of injury were enrolled. The patients were followed up for 6 months thereafter. The criteria for evaluating the degree of independence were applied to evaluate ADLs. Multivariable analysis with a logistic regression model was performed to evaluate the risk factors for ADL decline.

Results: In total, 49/224 patients (21.9%) showed a decline in ADLs. Of these, 23/116 patients (19.8%) in the rest group and 26/108 patients (24.1%) in the no-rest group experienced a decline in ADLs. In the logistic regression analyses, a diffuse low signal on T2- weighted magnetic resonance imaging (MRI) (odds ratio, 5.78; 95% confidence interval, 2.09-16.0; p=0.0007) and vertebral instability (odds ratio, 3.89; 95% confidence interval, 1.32-11.4; p=0.0135) were identified as independent factors in the rest and no-rest groups, respectively.

Conclusions: In patients with acute OVFs, a diffuse low signal on T2-weighted MRI and severe vertebral instability were independently associated with ADL decline in patients treated with and without initial bed rest, respectively.

Study design: A retrospective cohort study using the Kaplan-Meier method with propensity-score matching.

Purpose: To evaluate whether the presence of prevalent morphometric vertebral fractures (VFs) poses a risk for subsequent clinical VFs after short-fusion surgery in women aged ≥60 years with degenerative spondylolisthesis.

Overview of literature: VFs are common osteoporotic fractures and are associated with a low quality of life. Subsequent VFs are a complication of instrumented fusion in patients with degenerative lumbar disorders. Thus, risk factors for subsequent VFs after fusion surgery must be analyzed. Population-based studies have suggested that prevalent morphometric VFs led to a higher incidence of subsequent VFs in postmenopausal women; however, no studies have investigated whether prevalent morphometric VFs are a risk factor for subsequent VFs after fusion surgery in patients with degenerative spondylolisthesis.

Methods: The study enrolled a total of 237 older female patients: 50 and 187 patients had prevalent morphometric VFs (VF [+] group) and nonprevalent morphometric VFs (VF [-] group), respectively. The time to subsequent clinical VFs after fusion surgery was compared between the two groups using the Kaplan-Meier method. Moreover, 40 and 80 patients in the VF (+) and VF (-) groups, respectively, were analyzed and matched by propensity scores for age, follow-up duration, surgical procedure, number of fused segments, body mass index, and number of patients treated for osteoporosis.

Results: Kaplan-Meier analysis indicated that the VF (+) group had a higher incidence of subsequent clinical VFs than the VF (-) group, and Cox regression analysis showed that the presence of prevalent morphometric VFs was an independent risk factor for subsequent clinical VFs before matching. Kaplan-Meier analysis demonstrated comparable results after matching.

Conclusions: The presence of prevalent morphometric VFs may be a risk factor for subsequent clinical VFs in older women with degenerative spondylolisthesis who underwent short-fusion surgery.

Coronal malalignment (CM) has recently gained focus as a key predictor of functional outcomes in patients with adult spinal deformity (ASD). The kickstand rod technique has been described as a novel technique for CM correction using an accessory rod on the convex side of the deformity. This review aimed to evaluate the surgical technique and outcomes of corrective surgery using this technique. The literature search was conducted on three databases (PubMed, EMBASE, and Scopus). After reviewing the search results, six studies were shortlisted for data extraction and pooled analysis. Weighted means for surgical duration, length of stay, amount of coronal correction, and sagittal parameters were calculated. The studies included in the review were published between 2018 and 2023, with a total sample size of 97 patients. The mean age of the study cohort was 61.1 years, with female preponderance. The mean operative time was 333.6 minutes. The mean correction of CM was 5.1 cm (95% confidence interval [CI], 3.6-6.6), the mean sagittal correction was 5.6 cm (95% CI, 4.1-7.1), and the mean change in lumbar lordosis was 17° (95% CI, 10.4-24.1). Preoperative coronal imbalance and mean correction achieved postoperatively were directly related with age. The reoperation rate was 13.2%. The kickstand rod technique compares favorably with conventional techniques such as asymmetric osteotomies in CM management. This technique provides an additional accessory rod that helps increase construct stiffness. Because of limited data, definitive conclusions cannot be drawn from this review; however, this technique is a valuable tool for a surgeon dealing with ASD.

Study design: A retrospective analysis.

Purpose: To investigate the occurrence of central sensitization (CS) in patients with osteoporotic vertebral compression fractures (OVCFs) and identify the association between CS and residual back pain (RBP).

Overview of literature: RBP is a vexing complication that affects 6.3%-17.0% of patients with OVCFs who underwent percutaneous vertebroplasty (PVP). Given the negative effect of RBP on patients' psychological and physiological statuses, efforts to preoperatively select patients who are at risk for RBP development have a high priority to offer additional treatment and minimize this complication.

Methods: Preoperatively, all 160 patients with OVCFs underwent pressure-pain threshold (PPT), temporal summation (TS), conditioned pain modulation (CPM), and imaging assessments. Pain intensity and pain-related disability were evaluated before and after PVP.

Results: Preoperatively, patients with OVCFs had lower PPTs in both local pain and pain-free areas and lower CPM and higher TS in pain-free areas than healthy participants (p<0.05). Unlike patients with acute fractures, patients with subacute/chronic OVCFs showed higher TS with or without lower CPM in the pain-free area compared with healthy participants (p<0.05). Postoperatively, RBP occurred in 17 of 160 patients (10.6%). All preoperative covariates with significant differences between the RBP and non-RBP groups were subjected to multivariate logistic regression, showing that intravertebral vacuum cleft, posterior fascia edema, numeric rating pain scale scores for low back pain at rest, and TS were independently associated with RBP (p<0.05).

Conclusions: Augmented central pain processing may occur in patients with OVCFs, even in the subacute stage, and this preexisting CS may be associated with RBP. Preoperative assessment of TS in pain-free areas may provide additional information for identifying patients who may be at risk of RBP development, which may be beneficial for preventing this complication.

Study design: A retrospective case-control propensity score-matching study.

Purpose: This study aimed to longitudinally evaluate whether preoperative ligamentous stenosis at the spondylolisthetic segments could affect the incidence of symptomatic adjacent canal stenosis following one-segment fusion surgery.

Overview of literature: Several risk factors for symptomatic adjacent canal stenosis following fusion surgery have been assessed. Patients with lumbar canal stenosis mainly due to ligamentum flavum (LF) hypertrophy (ligamentous stenosis) also have LF hypertrophy in other segments.

Methods: In total, 76 patients participated in this case-control study (neurologically symptomatic adjacent canal stenosis, n=33; neurologically asymptomatic cases at follow-up, n=43). Their risk factors during surgery and magnetic resonance (MR) images before the surgery and at follow-up were evaluated. Data from the two groups (n=25 each) were matched using propensity scores for age, sex, time to MR imaging at follow-up, surgical procedure, and LF hypertrophy in adjacent segments before the surgery and analyzed.

Results: Compared with the asymptomatic group, the symptomatic adjacent canal stenosis group had a significantly larger LF area/spinal canal area in the spondylolisthetic segments before the surgery. During the follow-up periods (in months), they had a larger LF area/ spinal canal area in the adjacent segments: the two values were significantly correlated. The sensitivity, specificity, and positive and negative predictive values for determining symptomatic adjacent canal stenosis were high compared with on the cutoff value for the LF area/spinal canal area at the spondylolisthetic segments before the surgery. These results were the same after matching.

Conclusions: Symptomatic adjacent canal stenosis is mainly caused by LF hypertrophy. Ligamentous stenosis at the spondylolisthetic segments before fusion surgery might be strongly associated with symptomatic adjacent canal stenosis at follow-up.