Frailty is not an independent risk factor for worse clinical outcomes in lumbar spinal surgery: a prospective cohort study.

PURPOSE: Recently, many studies revealed that frailty affects unfavorably on postoperative outcomes in lumbar spinal diseases. This study aimed to investigate the relationship between frailty and clinical outcomes while identifying risk factors associated with worse clinical outcomes following lumbar spinal surgery. METHODS: From March 2019 to February 2021, we prospectively enrolled eligible patients with degenerative lumbar spinal diseases requiring surgery. Frailty was assessed preoperatively. To identify the impact of frailty on lumbar spinal diseases, clinical outcomes, which were measured with patient-reported outcomes (PROs) and postoperative complications, were compared according to the frailty. PROs were assessed preoperatively and one year postoperatively. In addition, risk factors for preoperative and postoperative worse clinical outcomes were investigated. RESULTS: PROs were constantly lower in the frail group than in the non-frail group before and after surgery, and the change of PROs between before and after surgery and postoperative complications were not different between the groups. In addition, frailty was a persistent risk factor for postoperative worse clinical outcome before and after surgery in lumbar spinal surgery. CONCLUSION: Frailty persistently affects the clinical outcome negatively before and after surgery in lumbar spinal surgery. However, as the change of the clinical outcome is not different between the frail group and the non-frail group, it is difficult to interpret whether the frail patients are vulnerable to the surgery. In conclusion, frailty is not an independent risk factor for worse clinical outcome in lumbar spinal surgery.

Effectiveness of intraoperative table modification for achieving lumbar lordosis in multilevel lumbar fusion surgery: a propensity score-matched study.

BACKGROUND: In multilevel posterior lumbar interbody fusion (PLIF) with posterior screw fixation, obtaining sufficient lumbar lordosis (LL) is difficult, especially in patients with osteoporosis. We performed intraoperative table modification (TM) using gravitational dropping of the patient's lumbar spine, to improve restoration of LL. METHODS: We retrospectively reviewed the medical records of patients who underwent three- or four-level PLIF between 2005 and 2019. One hundred eleven patients were enrolled, with 96 patients receiving non-TM-PLIF and 15 patients receiving TM-PLIF. Radiological parameters, including segmental lordosis (SL), LL, sacral slope (SS), pelvic incidence, and pelvic tilt, were measured. Clinical outcomes were measured using a visual analogue scale (VAS) for the back and leg preoperatively and at the last follow-up. Additionally, the correlation between the bone mineral density (BMD) and the radiological parameters was calculated for TM-PLIF. We performed propensity score matching between the groups to control the baseline difference. RESULTS: We found a statistically better correction between immediate and last follow-up postoperative SL (p = 0.04), as well as between preoperative and last follow-up SL (p < 0.01) in the TM-PLIF group compared to that in the non-TM-PLIF group. VAS for the back and leg were not significantly different between the two groups. Additionally, the efficacy of lordosis correction in the TM-PLIF group showed a statistically significant negative correlation between BMD and the SS change both before and after the surgery (rho = -0.60, p = 0.02). CONCLUSION: Whilst further study is required to conclusively establish its efficacy, TM-PLIF (table modification using gravitational dropping) shows potential advantages for restoring and maintaining LL in multilevel lumbar fusion, particularly in cases with low BMD.

Role of gamma knife radiosurgery for recurrent or residual World Health Organization grade II and III intracranial meningiomas.

Background: To analysis the role of gamma knife radiosurgery (GKRS) in treatment of the recurrent or residual World Health Organization (WHO) grade II and III meningiomas.Methods: Between 1995 and 2015, a total of 1163 meningioma patients were treated with GKRS at our single institute; 26 atypical and 6 anaplastic meningiomas were enrolled. The group consisted of 16 men and 16 women with a median age of 59.5 years (range 30-78 years). The median follow-up was 106.5 months (range 40-216 months). All were cases of tumour recurrence except 7 cases of residual lesions. Six patients were given fractionated radiotherapy before the initial course of GKRS (median dose, 56 Gy).Results: The median tumour volume was 3035 mm3 (range 247-11400 mm3). The median prescribed dose to high grade meningioma margin was 14 Gy (range 12-20 Gy,). The median prescribed dose to WHO II and III meningioma were 14 Gy (range 12-18 Gy) and 15 Gy (range 14-20 Gy), respectively. After radiosurgery, local tumour control rate was 50%. Tumour progression was observed in 28 patients; 16 recurrences were local (12 atypical and 4 anaplastic), 8 were marginal (7 atypical and 1 anaplastic), and 4 were distal (3 atypical and 1 anaplastic). Seven patients (21.88%) developed adverse radiation effects after GKRS. WHO grade was strongly associated with survival, with grade II showing a much longer survival (p = 0.01), and a prior history of radiation was associated with decreased survival (p = 0.003). Multivariate analysis showed that WHO grade (hazard ratio, HR: 5.051, p = 0.01) and prior radiation (HR: 5.763, p = 0.004) were independently associated with survival.Conclusions: WHO grade and a prior history of radiation therapy are reliable long-term predictors of overall outcome when treated with GKRS.

Clinically significant radiographic parameter for thoracic myelopathy caused by ossification of the ligamentum flavum.

PURPOSE: To investigate radiographic parameters to improve the accuracy of radiologic diagnosis for ossification of ligamentum flavum (OLF)-induced thoracic myelopathy and thereby establish a useful diagnostic method for identifying the responsible segment. METHODS: We classified 101 patients who underwent surgical treatment for OLF-induced thoracic myelopathy as the myelopathy group and 102 patients who had incidental OLF and were hospitalized with compression fracture as the non-myelopathy group between January 2009 and December 2016. We measured the thickness of OLF (TOLF), cross-sectional area of OLF (AOLF), anteroposterior canal diameter, and the ratio of each of these parameters. RESULTS: Most OLF cases with lateral-type axial morphology were in the non-myelopathy group and most with fused and tuberous type in the myelopathy group. Most grade-I and grade-II cases were also in the non-myelopathy group, whereas grade-IV cases were mostly observed in the myelopathy group. The AOLF ratio was found to be the best radiologic parameter. The optimal cutoff point of the AOLF ratio was 33.00%, with 87.1% sensitivity and 87.3% specificity. The AOLF ratio was significantly correlated with preoperative neurological status. CONCLUSIONS: An AOLF ratio greater than 33% is the most accurate diagnostic indicator of OLF-induced thoracic myelopathy. In cases of multiple-segment OLF, confirmation of cord signal change on MRI and an AOLF measurement will help determine the responsible segment. AOLF measurement will also improve the accuracy of diagnosis of OLF-induced thoracic myelopathy in cases of grade III or extended-type axial morphology. These slides can be retrieved under Electronic Supplementary Material.

Importance of the preoperative cross-sectional area of the semispinalis cervicis as a risk factor for loss of lordosis after laminoplasty in patients with cervical spondylotic myelopathy.

PURPOSE: To investigate the effect of the preoperative cross-sectional area (CSA) of the semispinalis cervicis on postoperative loss of cervical lordosis (LCL) after laminoplasty. METHODS: A total of 144 patients who met the inclusion criteria between January 1999 and December 2015 were enrolled. Radiographic assessments were performed to evaluate the T1 slope, C2-7 sagittal vertical axis (SVA), cephalad vertebral level undergoing laminoplasty (CVLL), preoperative C2-7 Cobb angle, and preoperative CSA of the semispinalis cervicis. RESULTS: The T1 slope and the summation of the CSAs (SCSA) at each level of the semispinalis cervicis correlated with LCL, whereas the C2-7 SVA, CVLL, and preoperative C2-7 Cobb angle did not. Multiple regression analysis demonstrated that a high T1 slope and a low SCSA of the semispinalis cervicis were associated with LCL after laminoplasty in patients with cervical spondylotic myelopathy (CSM). The CSA of the semispinalis cervicis at the C6 level had the greatest association with LCL, which suddenly decreased with a LCL of 10°. The best cutoff point of the CSA of the semispinalis cervicis at the C6 level, which predicts LCL > 10°, was 154.5 mm2 (sensitivity 74.3%; specificity 71.6%; area under the curve 0.828; 95% confidence interval 0.761-0.895). CONCLUSION: Preoperative SCSA of the semispinalis cervicis was a risk factor for LCL after laminoplasty. Spine surgeons should evaluate semispinalis cervicis muscularity at the C6 level when planning laminoplasty for patients with CSM. These slides can be retrieved under Electronic Supplementary Material.

Analysis of the Risk Factors Associated with Prolonged Intubation or Reintubation after Anterior Cervical Spine Surgery.

BACKGROUND: Standardized postoperative airway management is essential for patients undergoing anterior cervical spine surgery (ACSS). The paucity of clinical series evaluating these airway complications after ACSS has been resulted in a significant limitation in statistical analyses. METHODS: A retrospective cohort study was performed regarding airway distress (intubation for more than 24 hours or unplanned reintubation within 7 days of operation) developed after ACSS. If prevertebral soft tissue swelling was evident after the operation, patients were managed with prolonged intubation (longer than 24 hours). Preoperative and intraoperative patient data, and postoperative outcome (time to extubation and reintubation) were analyzed. RESULTS: Between 2008 and 2016, a total of 400 ACSS were performed. Of them, 389 patients (97.25%) extubated within 24 hours of surgery without airway complication, but 11 patients (2.75%) showed postoperative airway compromise; 7 patients (1.75%) needed prolonged intubation, while 4 patients (1.00%) required unplanned reintubation. The mean time for extubation were 2.75 hours (range: 0-23 hours) and 50.55 hours (range: 0-250 hours), respectively. Age (P = 0.015), diabetes mellitus (P = 0.003), operative time longer than 5 hours (P = 0.048), and estimated blood loss (EBL) greater than 300 mL (P = 0.042) were associated with prolonged intubation or reintubation. In prolonged intubation group, all patients showed no airway distress after extubation. CONCLUSION: In ACSS, postoperative airway compromise is related to both patients and operative factors. We recommend a prolonged intubation for patients who are exposed to these risk factors to perform a safe and effective extubation.

Radiosurgical decompression for benign perioptic tumors causing compressive cranial neuropathies: a feasible alternative to microsurgery?

Several studies have reported the efficacy and safety of hypofractionated stereotactic radiosurgery (hSRS) in the treatment of benign perioptic tumors. This study went further and evaluated the feasibility of hSRS in the treatment of those causing compressive cranial neuropathies (CCNs) among perioptic tumors with special consideration of functional improvement. Twenty-six patients with CCNs (CN II = 19; CN III/IV/VI = 9; CN V = 3) caused by perioptic tumors underwent hSRS between 2011 and 2015. hSRS was delivered in five fractions with a median marginal dose of 27.8 Gy (≈14 Gy in a single fraction, assuming an α/ß of three) to a tumor volume of 8.2 ± 8.3 cm3. All tumors except one shrank after treatment, with a mean volume decrease of 35 % (range 4-84 %) during the mean follow-up period of 20 months. In 19 patients (38 eyes) with compressive optic neuropathy, vision improved in 55.3 % of eyes (n = 21), was unchanged in 36.8 % (n = 14), and worsened in 7.9 % (n = 3) (2.6 % after excluding two eyes deteriorated due to transient tumor swelling). A higher conformity index (p = 0.034) and volume of the optic apparatus receiving >23.0 Gy (p = 0.019) were associated with greater tumor shrinkage. A greater decrease in tumor volume (p = 0.035) was associated with a better improvement in vision. Ophthalmoplegia and facial hypesthesia improved in six of nine (66.7 %) and three of three (100 %) patients, respectively. There was no newly developed neurological deficit. Decompressive SRS for benign perioptic tumors causing CCN is feasible using hypofractionation, representing a useful alternative to microsurgical resection.

Clinical analysis of C5 palsy after cervical decompression surgery: relationship between recovery duration and clinical and radiological factors.

BACKGROUND: Postoperative C5 palsy is a widely known complication of cervical decompression surgery. Many studies have focused on its etiology and factors affecting it. However, no study to date has evaluated the association between the clinical outcome and recovery duration of post-operative C5 palsy. We evaluated this in our current report. METHODS: A retrospective analysis was conducted for 710 consecutive degenerative cervical spine decompression surgeries performed in a single institution. We included all patients who underwent any type of surgical procedure for cervical spinal stenosis, ossification of posterior longitudinal ligament (OPLL), or cervical spondylotic myelopathy (CSM). Demographic, radiologic, clinical information was recorded. Finally, correlation analysis was conducted to identify demographic, radiologic, or clinical factors related with recovery duration (within or after 6 months). RESULTS: The incident rate of postoperative C5 palsy was 5.1 % (36/710 cases). Analysis of recovery duration revealed that 18 patients had recovered within 6 months and 33 (91.7 %) within 2 years, whilst 3 individuals (8.3 %) had not fully recovered within the follow-up period. Factors related to longer recovery (>6 months) included motor grade ≤2 (p < 0.001), presence of multi-segment paresis involving more than the C5 root (p = 0.002), loss of somatic sensation with pain (p = 0.008), and the degree of posterior spinal cord shifting (p = 0.040). Furthermore, multivariate analysis revealed that motor grade ≤2 (p = 0.010) had a significant effect on a recovery duration beyond 6 months. CONCLUSIONS: A motor grade ≤2, the presence of multi-segment paresis involving more than the C5 root, the loss of somatic sensation with pain, and the degree of posterior spinal cord shifting significantly influence whether the duration of recovery from postoperative C5 palsy will take longer than 6 months.

Prognostic factor analysis after surgical decompression and stabilization for cervical spinal-cord injury.

INTRODUCTION: Several studies have demonstrated the role of decompression surgery in preventing secondary injury and improving the neurological outcome after spinal cord injury (SCI). We retrospectively analyzed the prognostic factors affecting the outcomes of decompression surgery in patients with SCI. METHODS: We performed one-level decompression and fusion surgery on 73 patients with cervical SCI. We classified all patients based on their interval to decompression, sex, age, surgical level, presence of high signal intensity, American Spinal Injury Association Impairment scale (AIS) before surgery, blood pressure at admission, the amount of cord compression, surgical time, estimated blood loss during surgery, and steroid use. We considered an improvement to have occurred if the patient showed an AIS improvement of ≥1 grade. RESULTS: Among the 73 patients with SCI we analyzed, 27 and 35 showed ≥1 grade of AIS improvement immediately and 3 months after surgery, respectively. Using multivariate analysis, the mean arterial blood pressure (MAP) was a significant prognostic factor affecting recovery in the SCI patients during the immediate post-operative period. In the late recovery period at 3 months after surgery, the AIS before surgery and the MAP were significant prognostic factors affecting recovery. CONCLUSIONS: Prognostic factors for AIS improvement include the initial neurological status before surgery and hemodynamic MAP at admission. The interval between decompression surgery and trauma does not affect the neurological outcome.

Symptomatic adjacent segment degeneration at the L3-4 level after fusion surgery at the L4-5 level: evaluation of the risk factors and 10-year incidence.

PURPOSE: There have been few studies on revision surgery for clinically symptomatic adjacent segment degeneration (CASD). We aimed to find the incidence of revision surgery due to CASD and to analyze the factors that affected CASD at the L3-4 level after L4-5 or L4-5-S1 level fusion surgery over a long-term follow-up period. METHODS: Between January 2001 and October 2009, fusion surgeries were performed on 401 patients with spondylolisthesis at the L4-5 or L4-5-S1 level; 378 patients were followed up for a minimum of 2 years. We assessed CASD-free survival using Kaplan-Meier survival analysis. We also analyzed factors affecting the development of CASD, including sex, age, pelvic incidence, overall lordosis, segmental lordosis, lamina inclination angle, facet tropism, and the extent of disc and facet degeneration. Isthmic spondylolisthesis treated using total laminectomy or degenerative spondylolisthesis treated using subtotal laminectomy and interbody fusion (IBF) or posterolateral fusion (PLF) were also included in the risk factor analysis. The difference in disc height before and after initial surgery was also analyzed, as was inclusion of the sacrum in the fusion level. RESULTS: Fusion extension surgery was performed on 33 of these patients due to CASD at the L3-4 level during the follow-up period. Kaplan-Meier survival analysis indicated 3-, 5-, and 10-year disease-free survival rates of 99.20, 96.71, and 76.93 %. Statistically significant factors affecting CASD included old age, low overall lordosis, low segmental lordosis, progression of facet degeneration, total laminectomy-treated isthmic spondylolisthesis, and PLF-alone rather than IBF alone or IBF + PLF. CONCLUSION: We determined six significant factors affecting CASD development. Among these risk factors, facet degeneration, isthmic-type spondylolisthesis, and the type of fusion show higher hazard ratios and seem to be clinically more relevant than the other three factors (age, overall lordosis, and segmental lordosis).

Surgical strategies for removal of intra- and extraforaminal dumbbell-shaped schwannomas in the subaxial cervical spine.

PURPOSE: Spinal dumbbell-shaped schwannoma is common neoplasm, usually occurring in the cervical spine. Posterior or anterolateral approaches are frequently used to remove this benign tumor. We analyzed how much amount of tumor could be possible to be totally removed with posterior approach. METHOD: Surgery was performed on 41 cases of cervical, dumbbell-shaped subaxial schwannomas with both intra- and extraforaminal involvement. The same surgeon performed all the procedures. Mean follow-up was 42.5 months (24-108 months). A combined anterolateral and posterior approach was used if the extraforaminal tumor was larger than 10 mm. A posterior approach and unilateral facet removal were used if it was smaller than 10 mm. We performed MRI and serial dynamic X-rays for postoperative 2 years. RESULTS: We used the posterior approach with facetectomy in 35 cases and the combined approach in six. Complete removal was achieved with the combined approach in all six, and with the posterior approach in 28 of 35 cases. With the posterior approach, the extraforaminal dimension of totally resected tumors ranged from 3 to 5.4 mm. Subtotal resection was limited to extraforaminal tumors larger than 5.7 mm. On follow-up, instability on dynamic X-ray was not observed before 24 months in any patient after unilateral facetectomy. CONCLUSION: Total removal of intra- and extraforaminal cervical subaxial schwannomas could be possible using a posterior approach with facet removal if the size of extraforaminal tumor was less than 5.4 mm.

Experiences on two different stereotactic radiosurgery modalities of Gamma Knife and Cyberknife in treating brain metastases.

BACKGROUND: In this study, we compared the dosimetric properties between Gamma Knife (GK) and Cyberknife (CK), and investigated the clinical implications in treating brain metastases (BMs). METHODS: Between 2011 and 2013, 77 patients treated with either single-fraction GK for small BMs (n = 40) or fractionated CK for large BMs >3 cm (n = 37) were analyzed. Among a total of 160 lesions, 81 were treated with GK (median, 22 Gy) and 38 (large lesions) with three- or five-fraction CK (median, 35 Gy). The median tumor volume was 1.0 cc (IQR, 0.12-4.4 cc) for GK and 17.6 cc (IQR, 12.8-23.7 cc) for fractionated CK. A lesion-to-lesion dosimetric comparison was performed using the identical contour set in both systems. RESULTS: The mean dose to tumor was significantly higher in GK by 1.25-fold (P < 0.001), whereas normal tissue volume receiving 90-10 % of prescription dose was significantly larger in CK by 1.26-fold (P < 0.001). Nevertheless, no differences were observed in local tumor control (rates at 1 year, 89.7 % vs 87.0 %; P = 0.594) and overall survival (median, 14 vs 16 months; P = 0.493) between GK and fractionated CK groups. The incidences of radiation necrosis were also not different (12.3 % vs 15.8 %; P = 0.443). CONCLUSIONS: Despite slightly inferior dosimetric properties of CK, fractionated CK for large BMs appears to be as effective and safe as single-fraction GK for small BMs, representing fractionation as an effective strategy for enhancing efficacy and moderating toxicity in stereotactic radiosurgery for BMs.

Progression of lumbar spinal stenosis is influenced by polymorphism of thrombospondin 2 gene in the Korean population.

PURPOSE: The aim of this study is to determine the contribution of thrombospondin 2 (THBS2) polymorphisms to the development and progression of lumbar spinal stenosis (LSS) in the Korean population. METHODS: We studied 148 symptomatic patients with radiographically proven LSS and 157 volunteers with no history of back problems from our institution. Magnetic resonance images were obtained for all the patients and controls. Quantitative image evaluation for LSS was performed to evaluate the severity of LSS. All patients and controls were genotyped for THBS2 allele variations using a polymerase chain reaction-based technique. RESULTS: We found no causal single nucleotide polymorphism (SNPs) in THBS2 that were significantly associated with LSS. Two SNPs (rs6422747, rs6422748) were over-represented in controls [P = 0.042, odds ratio [OR] = 0.55 and P = 0.042, OR = 0.55, respectively]. Haplotype analysis showed that the ''AGAGACG'' haplotype (HAP4) and ''AAGGACG'' haplotype (HAP5) were over-represented in severe LSS patients (P = 0.0147, OR = 2.02 and P = 0.0137, OR = 2.48, respectively). In addition, the ''AAAGGGG'' haplotype (HAP1) was over-represented in controls (P = 0.0068, OR = 0.30). CONCLUSIONS: Although no SNPs in THBS2 were associated with LSS, haplotypes (HAP4 and HAP5) were significantly associated with progression of LSS in the Korean population, whereas another haplotype (HAP1) may play a protective role against LSS development.

Analysis on bilateral hindlimb mapping in motor cortex of the rat by an intracortical microstimulation method.

Intracortical microstimulation (ICMS) is a technique that was developed to derive movement representation of the motor cortex. Although rats are now commonly used in motor mapping studies, the precise characteristics of rat motor map, including symmetry and consistency across animals, and the possibility of repeated stimulation have not yet been established. We performed bilateral hindlimb mapping of motor cortex in six Sprague-Dawley rats using ICMS. ICMS was applied to the left and the right cerebral hemisphere at 0.3 mm intervals vertically and horizontally from the bregma, and any movement of the hindlimbs was noted. The majority (80%± 11%) of responses were not restricted to a single joint, which occurred simultaneously at two or three hindlimb joints. The size and shape of hindlimb motor cortex was variable among rats, but existed on the convex side of the cerebral hemisphere in all rats. The results did not show symmetry according to specific joints in each rats. Conclusively, the hindlimb representation in the rat motor cortex was conveniently mapped using ICMS, but the characteristics and inter-individual variability suggest that precise individual mapping is needed to clarify motor distribution in rats.

Is it necessary to use a cervical brace after single- or double-level ACDF?

Although anterior cervical discectomy and fusion (ACDF) is one of the most frequently performed spinal surgeries, there is no consensus regarding the necessity of prescribing a cervical brace after surgery. This study aimed to investigate any difference in radiological and clinical outcomes when wearing or not wearing cervical braces after single- or double-level ACDF. We examined 2 cohorts of patients who underwent single- or double-level ACDF surgery with and without a cervical brace: patients who underwent ACDF between March 2018 and December 2019 received a cervical brace, while patients who underwent ACDF between January 2020 and May 2021 did not. Each patient was evaluated radiologically and functionally using plain X-ray, modified Japanese Orthopedic Association score, and visual analog scale for neck and arm until 12 months after surgery. Fusion rate, subsidence, and postoperative complications were also evaluated. Eighty-three patients were included in the analysis: 38 were braced and 45 were not. The demographic characteristics and baseline outcome measures of both groups were similar. There was no statistically significant difference in any of the clinical measures at baseline. The modified Japanese Orthopedic Association score and visual analog scale for neck and arm were similar in both groups at all time intervals and showed statistically significant improvement when compared with preoperative scores. In addition, fusion rate, subsidence, and postoperative complications were similar in both groups. Our results suggest that the use of cervical braces does not improve the clinical outcomes of individuals undergoing single- or double-level ACDF.

Are There Advantages in Cervical Intrafacetal Fusion With Minimal Posterolateral Fusion (PLF) Compared to Conventional PLF in Posterior Cervical Fusion?

OBJECTIVE: We propose that cervical intrafacetal fusion (cIFF) using bone chip insertion into the facetal joint space additional to minimal PLF is a supplementary fusion method to conventional posterolateral fusion (PLF). METHODS: Patients who underwent posterior cervical fixation accompanied by cIFF with minimal PLF or conventional PLF for cervical myelopathy from 2012 to 2023 were investigated retrospectively. Radiological parameters including Cobb angle and C2-7 sagittal vertical axis (SVA) were compared between the 2 groups. In cIFF with minimal PLF group, cIFF location and PLF location were carefully divided, and the fusion rates of each location were analyzed by computed tomography scan. RESULTS: Among enrolled 46 patients, 31 patients were in cIFF group, 15 in PLF group. The postoperative change of Cobb angle in 1-year follow-up in cIFF with minimal PLF group and conventional PLF group were 0.1° ± 4.0° and -9.7° ± 8.4° respectively which was statistically lower in cIFF with minimal PLF group (p = 0.022). Regarding the fusion rate in cIFF with minimal PLF group in postoperative 6 months, the rates was achieved in 267 facets (98.1%) in cIFF location, and 244 facets (89.7%) in PLF location (p < 0.001). CONCLUSION: Postoperative sagittal alignment was more preserved in cIFF with minimal PLF group compared with conventional PLF group. Additionally, in cIFF with minimal PLF group, the bone fusion rate of cIFF location was higher than PLF location. Considering the concerns of bone chip migration onto the spinal cord and relatively low fusion rate in PLF method, applying cIFF method using minimized PLF might be a beneficial alternative for posterior cervical decompression and fixation.

Unilateral Pediculectomy and Reduction with Short-Segment Pedicle Screw Fixation for Thoracolumbar Burst Fracture: A Case Series.

BACKGROUND: This study aimed to evaluate the efficacy of unilateral pediculectomy and reduction with short-segment pedicle screw fixation for thoracolumbar burst fracture. METHODS: We retrospectively reviewed patients who underwent a unilateral pediculectomy and reduction with short-segment fixation and interbody fusion for thoracolumbar burst fracture. The unilateral pediculectomy created sufficient space to approach the ventral side of the spinal cord for removing bone fragments and insertion of an interbody cage to correct kyphosis. Lumbar lordosis (LL), pelvic incidence (PI) minus LL, and segmental Cobb angle were measured at 3 time points: preoperatively, postoperatively, and final follow-up. Furthermore, sagittal vertical axis (SVA) was measured to assess global sagittal balance at the final follow-up. RESULTS: A total of 10 patients, with a mean age of 39.8 ± 21.0, underwent the surgical procedure. All patients had a thoracolumbar injury classification and severity score > 5. The mean follow-up period was 15.8 ± 13.9 months. The mean postoperative LL (46.0 ± 5.8) was significantly higher (P = 0.008) than the preoperative measurement (32.8 ± 8.2). The mean postoperative PI minus LL (2.2 ± 8.4) was not significantly lower (P = 0.051) than preoperative measurement (15.4 ± 12.6). The mean postoperative segmental Cobb angle (11.4 ± 8.4) was significantly higher (P < 0.001) than the preoperative measurement (-11.6 ± 10.9). At the final follow-up, the mean sagittal vertical axiswas 10.0 ± 28.8 mm. CONCLUSIONS: Unilateral pediculectomy and reduction with short-segment fixation and interbody fusion served as an efficient surgical method for thoracolumbar burst fracture.

Quantitative Analysis of the Effect of Stereotactic Radiosurgery for Postoperative Residual Cervical Dumbbell Tumors: A Multicenter Retrospective Cohort Study.

OBJECTIVE: Stereotactic radiosurgery (SRS) has been performed for spinal tumors. However, the quantitative effect of SRS on postoperative residual cervical dumbbell tumors remains unknown. This study aimed to quantitatively evaluate the efficacy of SRS for treating postoperative residual cervical dumbbell tumors. METHODS: We retrospectively reviewed cases of postoperative residual cervical dumbbell tumors from 1995 to 2020 in 2 tertiary institutions. Residual tumors underwent SRS (SRS group) or were observed with clinical and magnetic resonance imaging (MRI) follow-up (observation group). Tumor regrowth rates were compared between the SRS and observation groups. Additionally, risk factors for tumor regrowth were analyzed. RESULTS: A total of 28 cervical dumbbell tumors were incompletely resected. Eight patients were in the SRS group, and 20 in the observation group. The mean regrowth rate was not significantly lower (p = 0.784) in the SRS group (0.18 ± 0.29 mm/mo) than in the observation group (0.33 ± 0.40 mm/mo). In the multivariable Cox regression analysis, SRS was not a significant variable (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.18-1.79; p = 0.336). CONCLUSION: SRS did not significantly decrease the tumor regrowth rate in our study. We believe that achieving maximal resection during the initial operation is more important than postoperative adjuvant SRS.

A prospective comparative study of radiological outcomes after instrumented posterolateral fusion mass using autologous local bone or a mixture of beta-tcp and autologous local bone in the same patient.

BACKGROUND: We previously reported a retrospective analysis of radiographic changes in instrumented posterolateral fusion mass (PLF) established using a mixture of local autologous bone and beta tricalcium phosphate (b-TCP) in lumbar spinal fusion surgery. Here, we report a prospective study to compare the use of local bone and a mixture of local bone and b-TCP in PLF in degenerative spinal surgery. METHODS: Radiological changes in the PLF mass in 42 patients were analyzed for 12 months. All patients had degenerative lumbar spinal disease and underwent instrumented fusion. Local autologous bone was used for PLF on the left side, and a mixture of local autologous bone and b-TCP was used for PLF on the right side. Lumbar spinal anterior-posterior (AP) images were performed immediately postoperative and at 1, 3, 6, and 12 months. Computed tomography (CT) was also done immediately postoperative and at 12 months. Fusion rate, radiodensity, and the dimensions of the PLF mass bilaterally on the AP X-ray were compared. The change in volume in both fusion bridges in the CT image was also compared. RESULTS: The overall fusion rates were 31/42 (73.8 %) and 24/42 (57.1 %) on the left and right sides, respectively. The decrease in radiodensity at 1 month postoperative was significantly greater on the left side than on the right side (from 0.79 to 0.74 versus from 0.81 to 0.78; p = 0.002). The mean immediate postoperative volume on the left side measured with CT was 5.1 cc (95 % CI, 4.94-5.34) and on the right side was 5.2 cc (95 % CI, 4.97-5.37). The mean volume at 12 months had decreased to 2.2 cc (95 % CI, 1.85-2.64) on the left side and 1.87 cc (95 % CI, 1.48-2.67) on the right side. The volume decrease on the right side was statistically greater than on the left side (p = 0.048). CONCLUSIONS: Based on the changes in radiodensity and fusion rate during follow-up, local bone seems to undergo earlier resorption and stabilization than the mixture of local bone and b-TCP..

Mid-term follow-up of clinical and radiologic outcomes in cervical total disk replacement (Mobi-C): incidence of heterotopic ossification and risk factors.

INTRODUCTION: Cervical arthroplasty has been shown to have successful, short-term and long-term radiologic and clinical outcomes. The incidence of and predisposing factors for heterotopic ossification (HO) have not been determined. We retrospectively assessed the intermediate-term clinical and radiologic outcomes, especially the incidence of HO and its risk factors. METHODS: Our patient population consisted of 75 patients (85 levels) with cervical disk herniation. Mean follow-up was 40 months, with a minimum follow-up of 24 months. The numeric rating scale scores of neck and arm pain, the neck disability index, and Odom criteria were measured preoperatively and at 24 months postoperatively. Cervical overall lordosis, segmental lordosis, and range of motion at the operative level were evaluated immediately after surgery and at 1, 3, 6, 12, and 24 months postoperatively. The incidence and location of HO were evaluated at 12 and 24 months postoperatively. Univariate and multivariate logistic regression analyses were performed to determine the risk factors for HO. RESULTS: The mean numeric rating scale scores and neck disability index scores decreased significantly over 24 months. According to Odom criteria, this represented an overall success rate of 86.7%. Mean segmental lordosis and motion increased and then decreased until 24 months. HO occurred in 67 levels at 12 months postoperatively, increasing to 80 levels at 24 months. The multivariate logistic regression test showed a statistically significant difference when using a different surgical technique (P = 0.049). CONCLUSIONS: Intermediate follow-up of cervical arthroplasty showed good clinical outcomes, although there was a trend toward reduction in alignment and motion at 24 months. The overall HO occurrence was 94.1% at 24 months. In our study, the most important factor affecting HO was the different surgical techniques.