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Study Design Retrospective cohort studyObjectives The criteria for determining completion of intervertebral stability after posterior lumbar interbody fusion (PLIF) remain controversial. Several new radiological indicators of bone growth and osteointegration have been established. We compared computed tomography (CT) findings related to osteointegration after PLIF with interbody cages of two different materials and designs.Methods We retrospectively analyzed data from 103 patients who underwent PLIF with three-dimensional porous tantalum (Tn) cages or titanium-coated polyetheretherketone (TiP) cages. CT images obtained 3 months and 1 year after surgery were examined for trabecular bone remodeling (TBR), cancellous condensation (CC), and vertebral endplate cyst (VEC) formation. The incidences of each finding were compared by cage type, and rates of instrument failure and pseudarthrosis were determined.Results Three months postoperatively, 87% of the levels with Tn cages exhibited TBR, whereas 96% of those with TiP cages did not (P < .001). Most levels with Tn cages levels exhibited TBR and no CC 3 months (81%) and 1 year (94%) after surgery. Although 78% of levels with TiP cages exhibited CC and no TBR 3 months after surgery, 59% exhibited both CC and TBR 1 year after surgery. Significantly fewer VECs formed around the Tn cages than around the TiP cages both 3 months (P = .002) and 1 year (P < .001) after surgery. Implant-related problems occurred at levels that exhibited neither TBR nor CC.Conclusions The porous tantalum cage may enable intervertebral stability that is comparable to bony fusion soon after surgery.

Study Design Retrospective multicenter studyObjectives To investigate changes over a 10-years period in the profile of cervical spine and spinal cord injuries among the elderly in Japan.Methods The current multicenter study was a retrospective analysis of inpatients aged ≥65 years, suffering cervical fracture (CF) and/or cervical spinal cord injury (CSCI). We analyzed 1413 patients’ epidemiology (from 2010 to 2019). Moreover, 727 patients who underwent surgical treatment were analyzed in 2 groups: the early (2010-2014) and late period (2015-2019).Results Both the number of patients and number of surgical patients showed a significant increasing trend (P< .001), while the mean age, the distribution of injury levels and paralysis severity, and the proportion of surgical indications remained the same. The number of surgical patients doubled from 228 to 499 from the early to late periods. Posterior surgery was the most common approach (90.4%), instrumentation surgery with screws increased significantly, and the range of fusion was significantly longer in the late period (2.1 vs 2.7 levels, P= .001). Significantly worsening neurological symptoms were recorded in the late period (1.3% vs 5.8%, P= .006), with C5 palsy being the major one. Otherwise, perioperative, major, and other complications, including mortality, did not differ significantly in incidence.Conclusions Both the number of elderly CF and/or CSCI patients and number of patients undergoing surgery increased dramatically over the decade without any change in profile. Instrumentation surgeries with screws increased, without an increase in systemic complications.

Study Design Retrospective cohort study.Objectives We newly found that trabecular bone remodeling (TBR) often appeared in the fixed adjacent vertebrae during bony fusion. Thus, TBR might indicate osteointegration. Hence, we aimed to investigate whether TBR in the early postoperative period could predict future bony fusion after posterior lumbar interbody fusion (PLIF).Methods We retrospectively analyzed 78 patients who underwent one-level PLIF. Demographic data were reviewed. Using computed tomography (CT) images taken at 3 months and 1 year postoperatively, we investigated the vertebral endplate cyst (VEC) formation, TBR in the vertebral body, cage subsidence, and clear zone around pedicle screw (CZPS).Results TBR had high interobserver reliability regardless of cage materials. VECs, TBR, and both were found in 30, 53, and 16 patients at 3 months postoperatively and in 30, 65, and 22 patients at 1 year postoperatively, respectively. The incidence of VEC, which indicates poor fixation, was lower in early (3 months postoperatively) TBR-positive patients, with a significant difference at 1 year postoperatively (3 months, P= .074; 1 year, P= .003). Furthermore, 3 (5.7%) of the 53 early TBR-positive patients had CZPS without instability at 1 year postoperatively. In 25 TBR-negative patients, 1 (4.0%) had pedicle screw cutout requiring reoperation, 1 (4.0%) had pseudarthrosis, and 4 (16%) had CZPS.Conclusions Patients with early TBR (3 months) did not experience pedicle screw cutout nor pseudarthrosis and had significantly fewer VECs than those without early TBR. Thus, TBR may be a new radiological marker of initial fixation after PLIF.

Study Design Retrospective analysis of prospectively databaseObjective Implant-related complications are an extremely important issue because they pose a burden to patients who underwent surgery. An understanding of these complications can help improve the postoperative management of patients undergoing spinal surgery. The current large-scale multicenter study aimed to identify postoperative implant-related complications that may require revision surgery.Methods In total, 3447 patients who underwent spinal fusion surgery were included in the analysis. Data about age at surgery, sex, preoperative diagnosis, surgical level, type of implant-related complications, causes of reoperation, and time from the initial to revision surgery were reviewed. Moreover, the characteristics of reoperation in 3 periods (within 30, 31–90, and over 90 days) were assessed.Result The overall incidence of implant-related complications was 4.6%. Adult spinal deformity was the most common diagnosis (9.9%), and thoracic-lumbar-sacral (42.9%) was the most common surgical level among patients with implant-related complications. Further, screw malposition was the most frequent implant-related complication (42.8%). In total, 89 (2.6%) patients underwent reoperation due to implant-related complications. The main causes of reoperation within 30, 31–90, and over 90 days were screw malposition (72.2%), screw loosening or pull out (81.8%), and rod or screw fracture (60.9%), respectively.Conclusion To the best of our knowledge, this was the first large-scale multicenter study that assessed the characteristics of patients who underwent reoperation due to spinal implant-related complications. The study results could improve the preoperative informed consent procedure about spinal fusion.

Study Design Retrospective multicenter cohort studyObjectives We aimed to clarify the efficacy of multimodal intraoperative neuromonitoring (IONM), especially in transcranial electrical stimulation of motor-evoked potentials (TES-MEPs) with spinal cord-evoked potentials after transcranial stimulation of the brain (D-wave) in the detection of reversible spinal cord injury in high-risk spinal surgery.Methods We reviewed 1310 patients who underwent TES-MEPs during spinal surgery at 14 spine centers. We compared the monitoring results of TES-MEPs with D-wave vs TES-MEPs without D-wave in high-risk spinal surgery.Results There were 40 cases that used TES-MEPs with D-wave and 1270 cases that used TES-MEPs without D-wave. Before patients were matched, there were significant differences between groups in terms of sex and spinal disease category. Although there was no significant difference in the rescue rate between TES-MEPs with D-wave (2.0%) and TES-MEPs (2.5%), the false-positivity rate was significantly lower (0%) in the TES-MEPs-with-D-wave group. Using a one-to-one propensity score-matched analysis, 40 pairs of patients from the two groups were selected. Baseline characteristics did not significantly differ between the matched groups. In the score-matched analysis, one case (2.5%) in both groups was a case of rescue (P= 1), five (12.5%) cases in the TES-MEPs group were false positives, and there were no false positives in the TES-MEPs-with-D-wave group (P= .02).Conclusions TES-MEPs with D-wave in high-risk spine surgeries did not affect rescue case rates. However, it helped reduce the false-positivity rate.

Study Design: Cross-sectional study.Objectives: To investigate the effects of pelvic compensation on standing balance in healthy volunteers.Methods: The 180 healthy volunteers were recruited at a basic health checkup. The inclusion criteria were: 1) age ≥ 65 years, 2) underwent a whole spine radiograph and stabilometry, 3) well-balanced standing posture with a sagittal vertical axis <50 mm, and 4) a visual analog scale of lower back pain of <20 mm. Based on the pelvic incidence (PI) and lumbar lordosis (LL) mismatch, subjects were divided into harmonious (PI–LL ≤ 10°) or unharmonious (PI–LL > 10°) groups.Results: Participants in the unharmonious group were significantly older compared with the harmonious group (70.2 ± 4.4 vs. 72.0 ± 4.6 years, P< .01). The PI minus LL values were −2.2° ± 7.5° and 16.6° ± 7.0° in the harmonious and unharmonious groups, respectively (P< .001). Anteroposterior LNG/TIME (average center of pressure sway speed) was significantly greater in the unharmonious group with both open and closed eyes (1.04 ± 0.38 cm/s vs. 1.25 ± 0.47 cm/s, P< .001 and 1.22 ± 0.54 cm/s vs. 1.58 ± 0.77 cm/s, P< .001, respectively). Lateral LNG/TIME was significantly greater in the unharmonious group only with closed eyes (1.24 ± 0.54 cm/s vs. 1.47 ± 0.79 cm/s, P= .03).Conclusions: Healthy elderly subjects with poor spinopelvic harmony had relatively unstable standing balance. The “cone of economy” was demonstrated, showing that unharmonious spinopelvic balance had a non-economic effect on standing.

Study Design: A retrospective review of clinical data and costs was performed for surgeries for adolescent idiopathic scoliosis (AIS) conducted from 2008 to 2017.Objective: Cost containment and healthcare value have become focal points in Japanese health care policy. The purpose of the study was to investigate trends over time in medical costs for surgery for AIS.Methods: A total of 83 patients underwent surgery for AIS from 2008 to 2017 at our hospital. Clinical data and length of stay were collected, and medical costs for surgery, local bone grafting, fees per day, and surgical instruments were evaluated.Results: There were slight year-by-year decreases in fees per day and decreases in costs of surgical instruments. The average length of stay was 16.4 days and gradually decreased over time. In contrast, scoliosis surgery costs increased about 1.6 times in 10 years from $9515 to $15 130.Conclusion: The trends for decreases in fees per day and prices for surgical instruments reflect recent government medical cost control policies. The cost for scoliosis surgery is also defined by the government, and the increase over 10 years may reflect the perspective of valuing effective and advanced surgeries. This study of cost trends of operative spinal intervention provides an assessment of surgical benefit and is likely to influence health care costs.

The goal of this prospective study was prospectively to investigate the relationship between obesity and spinal sagittal alignment.

Study Design: Retrospective study.Objectives: To elucidate risk factors for early-onset (2 months after initial kyphoplasty) adjacent vertebral fracture (EO-AVF) after kyphoplasty.Methods: A total of 108 vertebral bodies (95 patients) were included in this study. We examined patient backgrounds, the spinal level of EO-AVFs, surgery-related factors, and imaging findings. We divided the cases into 2 groups: patients with EO-AVF and patients without EO-AVF. Univariate, correlation, and multivariate analyses were conducted to reveal the risks factors for EO-AVFs for these 2 groups.Results: EO-AVFs developed in 28 vertebral bodies; they did not develop in 80 vertebral bodies. The overall EO-AVF incidence rate was 26%. The spinal level was the thoracolumbar junction for 93% of patients and another level for 7%, thus demonstrating the concentration of EO-AVFs in the thoracolumbar junction. For patients without EO-AVF and those with EO-AVF, there were significant differences in age (76 and 80 years, respectively), preoperative vertebral angles (VAs) (17.8° and 23°, respectively), and corrected VAs (7.3° and 12.7°, respectively). Significant differences were not observed for other factors. Pearson’s correlation coefficient was 0.661 (P< .000), thereby showing a significantly positive correlation between preoperative VAs and corrected VAs. Logistic regression analysis indicated that age (odds ratio, 1.112; 95% CI, 1.025-1.206) and preoperative VAs (odds ratio, 1.08; 95% CI, 1.026-1.135) were covariates and that the presence of an EO-AVF was a dependent variable. Therefore, both were predictable risk factors for EO-AVFs.Conclusion: Age, preoperative VAs, and corrected VAs are risk factors for EO-AVFs after kyphoplasty.

Study Design Prospective multicenter study.Objective To investigate the validity of transcranial motor-evoked potentials (Tc-MEP) in thoracic spine surgery and evaluate the impact of specific factors associated with positive predictive value (PPV).Methods One thousand hundred and fifty-six cases of thoracic spine surgeries were examined by comparing patient backgrounds, disease type, preoperative motor status, and Tc-MEP alert timing. Tc-MEP alerts were defined as an amplitude decrease of more than 70% from the baseline waveform. Factors were compared according to preoperative motor status and the result of Tc-MEP alerts. Factors that showed significant differences were identified by univariate and multivariate analysis.Results Overall sensitivity was 91.9% and specificity was 88.4%. The PPV was significantly higher in the preoperative motor deficits group than in the preoperative no-motor deficits group for both high-risk (60.3% vs 38.3%) and non-high-risk surgery groups (35.1% vs 12.8%). In multivariate logistic analysis, the significant factors associated with true positive were surgical maneuvers related to ossification of the posterior longitudinal ligament (odds ratio = 11.88; 95% CI: 3.17–44.55), resection of intradural intramedullary spinal cord tumor (odds ratio = 8.83; 95% CI: 2.89–27), preoperative motor deficit (odds ratio = 3.46; 95% CI: 1.64–7.3) and resection of intradural extramedullary spinal cord tumor (odds ratio = 3.0; 95% CI: 1.16–7.8). The significant factor associated with false positive was non-attributable alerts (odds ratio = .28; 95% CI: .09–.85).Conclusion Surgeons are strongly encouraged to use Tc-MEP in patients with preoperative motor deficits, regardless of whether they are undergoing high-risk spine surgery or not. Knowledge of PPV characteristics will greatly assist in effective Tc-MEP enforcement and minimize neurological complications with appropriate interventions.

Study Design Retrospective multicenter study.Objective The purpose of this study was to compare the prognosis of elderly patients with injuries related to cervical diffuse idiopathic skeletal hyperostosis (cDISH) to matched control for each group, with and without fractures.Methods The current multicenter study was a retrospective analysis of 140 patients aged 65 years or older with cDISH-related cervical spine injuries; 106 fractures and 34 spinal cord injuries without fracture were identified. Propensity score–matched cohorts from 1363 patients without cDISH were generated and compared. Logistic regression analysis was performed to determine the risk of early mortality for patients with cDISH-related injury.Results Patients with cDISH-related injuries with fracture did not differ significantly in the incidence of each complication and ambulation or severity of paralysis compared to matched controls. In patients with cDISH-related injury without fracture, those who were nonambulatory at discharge comprised 55% vs 34% of controls, indicating significantly poorer ambulation in those with cDISH-related injuries (P= .023). There was no significant difference in the incidence of complications and ambulation or paralysis severity at 6 months as compared with controls. Fourteen patients died within 3 months. Logistic regression analysis identified complete paralysis (odds ratio [OR] 36.99) and age (OR 1.24) as significant risk factors for mortality.Conclusions The current study showed no significant differences in the incidence of complications, ambulation outcomes between patients with cDISH-related injury with fracture and matched controls, and that the ambulation at discharge for patients with cDISH-related injury without fractures were significantly inferior to those of matched controls.

Sufficient internal fixation for occipitocervical (OC) or C1–C2 instability in pediatric patients with Down syndrome is difficult owing to small osseous structures, congenital deformities, and immature ossification. The purpose of this study was to evaluate the clinical outcomes of patients aged 8 years or younger with Down syndrome who underwent OC or C1–C2 fusion using freeze-dried allograft as bone graft substitute. The participants included seven consecutive patients aged 8 years or younger with Down syndrome who were treated for upper cervical disorders with posterior OC or C1–C2 fusion using freeze-dried allografts at our hospital between 2007 and 2016 and had a minimum follow-up of 1 year. Postoperative flexion/extension cervical radiography and computed tomography were repeated at 3 months after surgery before removal of the collar. The modified McCormick scale was used to grade functional status. The seven patients had an age range of 5–8 years (mean: 5.9 years). The mean follow-up period was 36 months (12–120 months). Six patients had os odontoideum and one had basilar invagination. Three patients underwent C1–C2 fusion, and in all cases, bilateral C1 lateral mass screws and bilateral C2 pedicle screws were used. Four patients underwent OC fusion, and in three of these cases, occipital and bilateral pedicle screws were used. One patient underwent reoperation because of occipital screw back-out with autograft; therefore, C2 lamina screws were added to pedicle screws. Solid bony fusion was achieved, and stable constructs were maintained on radiography in all patients, without infection or implant failure. In this study, we used freeze-dried allograft as a bone graft substitute, and we were able to detect bony trabeculae at the graft–recipient interface on lateral cervical radiographs and on reconstructed sagittal computed tomographic images in all patients. These results suggest that use of allograft is effective for treatment of upper cervical spine abnormalities in pediatric patients with Down syndrome.

Study Design: Prospective clinical study.Objective: Many oral surgeons use platelet-rich plasma (PRP) for bone defects, but the efficacy of PRP for spinal arthrodesis remains uncertain. The objective was to compare the efficacy of autologous local bone graft and PRP with local bone graft alone for promotion of bony union in posterolateral lumbar fusion (PLF) surgery, with investigation of the safety of PRP over 10 years.Methods: A prospective study was conducted in 29 consecutive patients who underwent one-level PLF at L4/5 for degenerative lumbar disease. Local bone on the left (control) side and local bone with PRP on the right side were grafted. The fusion area and absorption of grafted bone at 58 regions were determined using computed tomography at 2 weeks and 3, 6, and 12 months after surgery.Results: Average bone fusion areas on the PRP side were significantly wider at 3 and 6 months after surgery (P< .05). Average absorption values were significantly lower on the PRP side than on the control side at 3 and 6 months after surgery (P< .05). The PRP/control ratio was significantly different at 3 and 6 months compared to that at 2 weeks (P< .005). No adverse events related to PRP occurred with good clinical outcome over 10 years follow-up.Conclusions: Local application of PRP combined with autologous local bone graft has a positive impact on early fusion for lumbar arthrodesis with no adverse events over 10 years, and thus is a safe and low cost autologous option in spinal fusion.

Study Design: Prospective study.Objective: Investigate factors associated with preoperative motor paresis, recovery, ambulatory status, and intraoperative neurophysiological monitoring (IONM) among patients with no preoperative paresis (N group), complete preoperative motor recovery (CR group), and no complete recovery (NCR group) in patients with intramedullary spinal cavernous hemangioma to determine the optimal timing of surgery.Methods: The study evaluated 41 surgical cases in our institute. Disease duration, tumor lesion, manual muscle testing (MMT), and gait at onset, just before surgery, and final follow-up (FU), tumor and lesion volume, IONM, extent of tumor resection, and tumor recurrence were evaluated among N, CR, and NCR groups.Results: Motor paresis at onset was found in 26 patients (63%), with 42% of those in CR group. Disease duration from onset negatively affected stable gait just before surgery and FU as well as lower preoperative MMT (P< .05). Thoracic tumors were associated with patients with unstable gait before surgery (P< .05). Tumor volume was larger in NCR group (P< .05). IONM significantly decreased in NCR and CR groups than in N group (P< .05). The NCR group had residual mild motor paresis at FU (P< .05). Stable gait at FU was similar in N group and CR group, though lower in NCR group (P< .05).Conclusions: Early surgery is generally recommended for thoracic tumors and large tumors during stable gait without motor paresis before long disease duration. Surgery may be postponed until patients recover from preoperative motor paresis to allow optimal surgical outcome. IONM should be carefully monitored in patients with a history of preoperative paresis even with preoperative complete motor recovery.

BACKGROUND:Thoracic ossification of the posterior longitudinal ligament (T-OPLL) is treated surgically with instrumented posterior decompression and fusion. However, the factors determining the outcome of this approach and the efficacy of additional resection of T-OPLL are unknown.OBJECTIVE:To identify these factors in a prospective study at a single institution.METHODS:The subjects were 70 consecutive patients with beak-type T-OPLL who underwent posterior decompression and dekyphotic fusion and had an average of 4.8 years of follow-up (minimum of 2 years). Of these patients, 4 (6%; group R) had no improvement or aggravation, were not ambulatory for 3 weeks postoperatively, and required additional T-OPLL resection; while 66 (group N) required no further T-OPLL resection. Clinical records, gait status, intraoperative ultrasonography, intraoperative neurophysiological monitoring (IONM), plain radiography, computed tomography and magnetic resonance imaging findings, and Japanese Orthopaedic Association (JOA) score were compared between the groups.RESULTS:Preoperatively, patients in group R had significantly higher rates of severe motor paralysis, nonambulatory status, positive prone and supine position test, no spinal cord floating in intraoperative ultrasonography, and deterioration of IONM at the end of surgery (P< .05). In preoperative radiography, the OPLL spinal cord kyphotic angle difference in fused area, OPLL length, and OPLL canal stenosis were significantly higher in group R (P< .05). At final follow-up, JOA scores improved similarly in both groups.CONCLUSION:Preoperative severe motor paralysis, nonambulatory status, positive prone and supine position test, radiographic spinal cord compression due to beak-type T-OPLL, and intraoperative residual spinal cord compression and deterioration of IONM were associated with ineffectiveness of posterior decompression and fusion with instrumentation. Our 2-stage strategy may be appropriate for beak-type T-OPLL surgery.

Study Design Prospective clinical study.Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as “resection at an anterior site of the spinal cord from a posterior approach” (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL.Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases.Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications.Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis.

A prospective multicenter cohort study. To clarify the differences in the accuracy of transcranial motor-evoked potentials (TcE-MEPs) and procedures associated with the alarms between cervical anterior spinal fusion (ASF) and posterior spinal fusion (PSF). Neurological complications after TcE-MEP alarms have been prevented by appropriate interventions for cervical degenerative disorders. The differences in the accuracy of TcE-MEPs and the timing of alarms between cervical ASF and PSF noted in the existing literature remain unclear. Patients (n = 415) who underwent cervical ASF (n = 171) or PSF (n = 244) at multiple institutions for cervical spondylotic myelopathy, ossification of the posterior longitudinal ligament, spinal injury, and others were analyzed. Neurological complications, TcE-MEP alarms defined as a decreased amplitude of ≤70% compared to the control waveform, interventions after alarms, and TcE-MEP results were compared between the 2 surgeries. The incidence of neurological complications was 1.2% in the ASF group and 2.0% in the PSF group, with no significant intergroup differences (P-value was .493). Sensitivity, specificity, negative predictive value, and rate of rescue were 50.0%, 95.2%, 99.4%, and 1.8%, respectively, in the ASF group, and 80.0%, 90.9%, 99.5%, and 2.9%, respectively, in the PSF group. The accuracy of TcE-MEPs was not significantly different between the 2 groups (P-value was .427 in sensitivity, .109 in specificity, and .674 in negative predictive value). The procedures associated with the alarms were decompression in 3 cases and distraction in 1 patient in the ASF group. The PSF group showed Tc-MEPs decreased during decompression, mounting rods, turning positions, and others. Most alarms went off during decompression in ASF, whereas various stages of the surgical procedures were associated with the alarms in PSF. There were no significant differences in the accuracy of TcE-MEPs between the 2 surgeries.

A case-control clinical study.

This is a prospective study on surgical outcomes of double-door laminoplasty in patients with cervical spondylotic myelopathy (CSM).

Lumbar spine synovial cysts are becoming more frequent, and they are generally associated with degenerative lumbar spinal disease. They are common in lower lumbar lesions but rare in upper lumbar lesions. Several cases of hemorrhage into lower lumbar juxtafacet cysts after trauma or anticoagulation therapy have been reported in the literature. This article describes a case of subacute cauda equina syndrome resulting from spontaneous hemorrhage into an upper lumbar synovial cyst.A 65-year-old man presented with a 3-month history of intermittent bilateral lumbar pain. One week before, he experienced a sudden exacerbation of lumbar pain and began falling frequently; he also reported weakness and tingling in his lower limbs. A hematic collection associated with a large juxtafacet cyst at L2–L3 was suspected on magnetic resonance imaging. He underwent surgical decompression, and the cyst was resected. Microscopic examination was consistent with the diagnosis of a synovial cyst. Two days postoperatively, he was walking independently.Although several descriptions exist of hemorrhagic lumbar juxtafacet cysts after trauma or anticoagulant therapy, to the authors’ knowledge, this is the first documented case of hemorrhage in an upper lumbar synovial cyst with no previous traumatic event or medication use. Magnetic resonance imaging was essential in making the preoperative diagnosis. Surgical removal of the cyst was an effective treatment.

A case-control clinical study of preemptive analgesia for postoperative pain was conducted.

Little is known about the progression of Thoracolumbar kyphosis (TLK) in achondroplasia. The aim of the study was to evaluate natural progression of TLK and establish risk factors for progression.

The study aimed to establish the spinal cord occupation rate of the dural sac during flexion and extension.

The goal of spinal fusion in the reconstructive spinal surgery is to achieve solid bony fusion between vertebral segments. The purpose of this study was to investigate the efficacy of low-intensity pulsed ultrasound (LIPUS) in enhancing fusion rate and bone formation after one-level posterior lumbar interbody fusion (PLIF).