Pedicle Screw Fixation Research Articles

Posterior Spinal Fusion for Severe Kyphosis in a Child with Gaucher Disease: A Case Report and Review of the Literature

Background: Skeleton involvement is one of the most significant aspects of Gaucher disease (GD). However, the treatment for spinal involvement in GD among patients undergoing enzyme replacement therapy (ERT) is poorly characterized. We present a case of progressive kyphotic spinal deformity in a young child caused by vertebral involvement, which was managed by posterior spinal fusion without anterior spinal release under ERT. Case presentation: This is a retrospective study. A 10-year-old boy presenting with progression kyphosis (thoracic kyphotic angle of 113°) associated with type-IIIb GD had undergone posterior spinal fusion with segmental pedicle screw fixation (from T6-L3) and Ponte osteotomy. The patient went back to school without further brace protection. Proximal junctional kyphosis (PJK) was observed at 4 months postoperatively. Revision surgery was performed to prevent neurological impairment. Additional posterior spinal fusion from T2–T6 and decompressive laminectomy were performed during the revision surgery. A 2-year follow-up showed no recurrence of PJK and solid fusion was achieved in the patient under ERT and brace protection. Conclusions: Posterior spinal fusion without anterior spinal release is a good treatment option for severe spinal deformity in patients with GD. However, the fusion level and reinforced fixation require careful consideration. Revision surgery and brace protection is needed as long as PJK is observed.

A novel technique for C1-C2 posterior screw insertion using patient-specific guides created by CT-based 3D printing.

C1-C2 fixation has been developed for the rigid fusion of atlantoaxial instability. C1 lateral mass screw (C1 LMS)-C2 pedicle screw fixation is used more frequently due to its rigid fixation and high bone fusion rate. However, C1 screw placement is relatively unsafe even with recently developed image-based navigation systems. Patient-specific screw guide templates (PSGT) were developed to improve the accuracy and safety of C1 screw placement. Herein, we investigated the outcomes of the C1-C2 posterior fixation technique using PSGT. This was a retrospective study of six patients who underwent posterior cervical spinal fusion using the PSGT between January 2022 and April 2023. Operative time, estimated blood loss, intraoperative radiation dose, surgical cost, and screw placement accuracy were evaluated and compared with those achieved with preoperative CT-based navigation (navigation group, n = 15). Screw accuracy was assessed using Neo's classification. PSGT showed good results, although the differences were not statistically significant (operation time: 104.3 ± 9.7 min vs 116.4 ± 20.8 min; estimated blood loss: 56.7 ± 72.4 mL vs 123.2 ± 162.3 mL; and radiation dose: 1.8 ± 1.2 mSv vs 2.6 ± 0.8 mSv, respectively). PSGT was particularly better in terms of the accuracy of C1 LMS (PSGT: 100%, navigation: 83.3%). The deviation at the entry point was minimal, and the difference between the sagittal and transversal angles from the preoperative plan was small. We investigated the clinical efficacy of using the PSGT for C1-C2 posterior fixation. PSGT improved the accuracy of C1 LMS insertion.

Comparison of rostral facet joint violations in robotic- and navigation-assisted pedicle screw placement for adult lumbar spine instrumentation

BACKGROUND CONTEXTFacet joint violation by pedicle screws may lead to adjacent-segment disease and postoperative pain. Previous studies have reported the incidence of rostral facet joint violation using various pedicle screw insertion techniques. However, the incidence of facet joint violations with robotic guidance has not been determined. PURPOSETo investigate and compare the incidence of rostral facet joint violation by pedicle screws under robotic guidance and computerized tomography (CT) navigation guidance. STUDY DESIGN/SETTINGRetrospective matched cohort. PATIENT SAMPLEAll patients who underwent robotic-assisted lumbar fusion at a major spine center up until 2023 were retrospectively identified and matched 1:3 to patients undergoing CT navigation guidance based by on age, sex, rostral vertebral level, and length of construct. Inclusion criteria consisted of age greater than 18 years, bilateral pedicle screw fixation, and presence of a postoperative CT scan of the lumbar spine or abdomen/pelvis at any point in the post-operative period. OUTCOME MEASURESRostral facet joint violations. METHODSDescriptive statistics were used to compare cohorts: frequencies, chi-squared analysis for categorical variables, and t-test for continuous variables. RESULTSA total of 408 rostral pedicle screws were implanted in 204 patients (Robot: 102; Navigation: 306). Overall, 13 (12.3%) rostral facet joint violations were observed in the robot cohort and 75 (24.5%) in the navigation cohort (p=.01). Specifically, fewer robotic violations were observed at the L2 (3.5% vs. 32.1%, p=.003) and L3 levels (3.9% vs. 18.1%, p=.08) compared to navigation. No difference was observed at L4 and L5. Bilateral violations are significantly reduced with robotic approaches (5.3% vs. 14.4%, p=.03). Lastly, more facet joint violations were observed during open approaches (robot: 18.8%, navigation: 27.3%) than percutaneous approaches (robot: 11.6%, navigation: 7.1%) in both groups (p<.001). The rate of L4 facet violations was 18.8% in the robotic cohort and 27.3% in the navigation cohort. The rate of L5 facet violations was 31.3% in the robotic cohort and 29.2% in the navigation cohort. CONCLUSIONSUse of robotic assistance in lumbar pedicle screws significantly reduced the rate of rostral facet joint violations compared to navigation guidance at L2 and L3 levels, but not at L4 and L5, with facet violations approaching nearly one-third of the patients at L5 screws. Rostral facet violations can play a significant role in adjacent segment degeneration and disease. Technical factors and trajectory issues likely play a role and addressing these components should minimize unintended facet violation and proximal adding on.

Outcomes of Thoracolumbar Burst Fractures Treated With Open Versus Minimally Invasive Percutaneous Posterior Spinal Stabilization: A Retrospective Study at a Rural Teaching Hospital in South India.

Background Thoracolumbar spine fractures are the most prevalent type of axial skeleton fractures, with approximately two-thirds occurring between T11 and L2. Percutaneous pedicle screw fixation has been reported to be an effective treatment for thoracolumbar fractures. Minimally invasive percutaneous pedicle screw fixation yields outcomes comparable to those of the standard open procedure and has the advantages of less stress, bleeding, and pain, as well as rapid postoperative recovery. The main objective of this research was to compare the clinical and radiological outcomes of two surgical approaches (open and percutaneous posterior spinal stabilization), concentrating on nonosteoporotic AO Spine Type A3 thoracolumbar burst fractures between T11 and L2. Materials and methods We conducted a retrospective study in our hospital, where cases of thoracolumbar burst fractures meeting the inclusion criteria were chosen retrospectively from April 2022 to March2023. A total of 54 patients (aged 18-60 years) who underwent spinal stabilization were included in this investigation. The population was divided into two cohorts, with 27 patients in each: Group A underwent open posterior spinal stabilization, and Group B underwent percutaneous posterior spinal stabilization. Data retrieved from medical records were analyzed with at least a six-month follow-up, mainly assessing the demographic data, intraoperative parameters, duration of hospitalization, clinical outcomes (Visual Analog Scale, Oswestry Disability Index, and McGill Pain Questionnaire scores), and radiological outcomes (vertebral wedge angle and correction loss). Results Both groups had a male preponderance. There were statistically meaningful distinctions between both groups regarding intraoperative parameters (blood loss and surgical duration) and primary clinical outcome parameters (Visual Analog Scale, Oswestry Disability Index, and McGill Pain Questionnaire scores) in the early phase of the study. However, there were no statistically significant differences concerning radiological parameters (vertebral wedge angle and correction loss) or primary clinical outcome parameters at the last follow-up. Conclusion The treatment modalities (open and percutaneous posterior spinal stabilization surgery) were equally safe and effective. However, the percutaneous group demonstrated significant reductions in the length of the surgical procedure, blood loss during surgery, duration of hospital stay, and immediate postoperative pain scores, all of which could potentially benefit patients.

Accuracy and Safety of Freehand Placement of Upper Thoracic Pedicle Screws Supported Solely by Anteroposterior, i.e., Frontal, X-Ray Fluoroscopy (C-Arm): Technical Note Including 23 Patients

IntroductionThe biomechanical resistance and the surgical morbidity of spinal posterior pedicle screw fixation relies on the intraosseous position of the implants. Upper thoracic pedicle screws are particularly demanding given their convergence and thin character. We present our experience as military surgeons of free hand placement of upper thoracic pedicle screws supported by antero-posterior, i.e. frontal X-ray fluoroscopy solely. Materials and methodsMonocentric retrospective analysis at Sainte-Anne Military Teaching Hospital between 2017 and 2024 of patients operated on using upper thoracic pedicle screws (levels T1 to T5) using antero-posterior fluoroscopy solely. Results23 patients were included (mean age 59, male/female 3.6), 16 traumas and 7 neoplastic lesions), with 15 cervicothoracic junction fixation and 8 upper thoracic spine surgeries. 124 screws were inserted (T1 to T5). 85% (106/124) were graded 0 (Gertzbein-Robbins scale) whereas 14.5% (18/124) displayed some degree of misplacement (grade 1 to 3): all the T1 screws (22/22) were accurately placed compared to 83% (20/24) of T2 screws, 88% (30/34) of T3 screws, 85% (17/20) of T4 screws, and finally 71% (17/24) of T5 screws, without any clinical consequences. There were 3 surgical revisions (1 asymptomatic misplaced screw, 2 mechanical failures in trauma). Last, 92.7% (n=51/55) of the screws inserted during working hours were accurately placed compared to 79.7% (n=55/69) during after-hours surgeries (p=0.039) ConclusionClinically speaking, placement of upper thoracic pedicle screws using antero-posterior fluoroscopy solely appears safe. The surgical technique is simple enough to be used in strained resources settings such as a mobile field surgical team.

Results of cement-augmented pedicle screw surgery in the treatment of thoracic and lumbar spine collapse in severe osteoporosis patients

Objective: This 2023 study aimed to assess pain relief, functional recovery, and kyphosis correction following pedicle screw surgery with cement augmentation in severe osteoporosis patients with vertebral collapse. Methods: Seventy-one patients underwent surgery and were evaluated for postoperative pain reduction (VAS score), functional improvement (ODI score), vertebral kyphosis angle, pre- and postoperative spinal curvature angles, and complications. Results: The study included 71 participants (13 males, 58 females; mean age 67.6±6.7 years). Trauma sources included falls (47.9%), heavy lifting (17%), and unclear mechanisms (35.2%). Mean hospital stay was 12±6.5 days. Preoperative, postoperative, and 1/6-month VAS scores were 8.7, 2.2, 1.5, 0.9 respectively (p&lt;0.001). ODI scores were 77.6, 52.8, 43.0, 37.9 respectively (p&lt;0.001). Kyphotic angle (vertebral body) decreased from preop 12.9° to postop 9.9°, 1/6 months 10.1° (p&lt;0.001); at surgical site, preop 15.4° to 1/6 months 11.9° (p&lt;0.001). Cement leakage occurred in 36.6% of cases, mostly asymptomatic, with distribution in the disc space (2.8%), blood vessels (8.5%), around vertebral body (12.7%), spinal canal (14.1%), and lungs (2.8%). Conclusion: Pedicle screw fixation with enhanced cement augmentation effectively manages severe osteoporotic vertebral compression fractures, providing significant pain relief, improved postoperative function, and spinal alignment. Symptomatic cement leakage is rare.

The comparison study of laminectomy with unilateral and bilateral pedicle screws fixation and laminectomy alone without fusion interbody in young patients with lumbar spinal stenosis: A randomized clinical trial

BackgroundThere are many reports about the risk factors for recurrence after laminectomy surgery. Some surgeons use unilateral and bilateral fusion to provide sufficient stability to the lumbar spine. However, its strength, safety, and effectiveness in young patients are not widely known. Therefore, this study was conducted to compare surgical methods of laminectomy with unilateral and bilateral fixation and laminectomy alone without interbody fusion in young patients with lumbar spinal stenosis. Methods90 patients eligible for lumbar spinal stenosis surgery were selected through convenience sampling and randomly divided into three groups: laminectomy without fixation (A), laminectomy with unilateral fixation (B), and bilateral fixation (C). Pain, functional disability, quality of life, recurrent disc, adjacent segment disease (ASD), and fusion rate were evaluated and compared among the three groups six months post-surgery. The data were analyzed using SPSS version 16. ResultsSix months after surgery, the mean score of functional disability in the bilateral group was significantly higher than the other groups (12.92 (3.30) vs 5.52 (1.91) and 4.30 (1.84), P < 0.05). Also, the highest mean score of pain after surgery was observed in the bilateral group (4.33 (0.70) vs 1.81(0.68) and 1.63(0.56), P < 0.05). The mean score of quality of life in the unilateral group was significantly higher than the other groups (87.81 (5.67) vs 68.58 (3.08) and 56.07 (4.04), P < 0.05). No significant difference was observed between the groups (P > 0.05) regarding fusion, recurrent disc herniation, and adjacent segment disease. ConclusionsUnilateral fixation provides the same benefits as bilateral fixation but has the additional benefits of being less invasive and minimizing the disadvantages of other investigated techniques during and after surgery.

Higher Accuracy and Better Clinical Outcomes in Navigated Thoraco-Lumbar Pedicle Screw Fixation Versus Conventional Techniques : A Systematic Review and Meta-Analysis.

A systematic review and meta-analysis. This study aims to compare pedicle screw accuracy, clinical outcomes, and complications between navigated and conventional techniques. In the last decades, intraoperative navigation has been introduced in spinal surgery to prevent risks and complications. The search was executed on Cochrane Central Library, PubMed, and Scopus on April 30, 2023. Randomized controlled trials, prospective and retrospective studies that compared pedicle screw accuracy in the thoracic-lumbar-sacral segments, blood loss, operative time, hospital stay, intraoperative and postoperative revision of screws, neurological and systemic complications, Visual Analogue Scale (VAS), and Oswestry Disability Index (ODI) between navigated and freehand or fluoroscopy-assisted techniques were included in this study. The meta-analysis was performed using Review Manager software. Clinical outcomes were assessed as continuous outcomes with mean difference, while pedicle screw accuracy and complications were assessed as dichotomous outcomes with odds ratio, all with 95% CIs. The statistical significance of the results was fixed at P <0.05. This meta-analysis included 30 studies for a total of 17,911 patients and 24,600 pedicle screws. Statistically significant results in favor of the navigated technique were observed for the accuracy of pedicle screws ( P =0.0001), hospital stay ( P =0.0002), blood loss ( P <0.0001), postoperative revision of pedicle screws ( P <0.00001), and systemic complications ( P =0.0008). In particular, the positioning of the screws was clinically acceptable in 96.2% of the navigated group and 94.2% with traditional techniques. No significant differences were found in VAS, ODI, and operative time between the two groups. Navigated pedicle screw fixation has been demonstrated to be a safe and effective technique with high improvement in clinical outcomes and accuracy in patients undergoing spinal fusion compared with conventional techniques. Level III.

Application of polyetheretherketone rod semi-rigid pedicle screw internal fixation in lumbar non-fusion surgery

To investigate the effect of Polyetheretherketone (PEEK) rod semi-rigid pedicle screw fixation system in lumbar spine non-fusion surgery. A total of 74 patients with tow-level lumbar degenerative diseases who underwent surgery from March 2017 to December 2019 were divided into PEEK rod group and titanium rod group. In the PEEK rod group, there were 34 patients, including 13 males and 21 females, aged from 51 to 79 years old with an average of (62.4±6.8) years old;There were 1 patient of L1-L3 segments, 7 patients of L2-L4 segments, 20 patients of L3-L5 segments and 6 patients of L4-S1 segments. In the titanium rod group, there were 40 patients, including 17 males and 23 females, aged from 52 to 81 years old with an average of (65.2±7.3) years old;There were 3 patient of L1-L3 segments, 11 patients of L2-L4 segments, 19 patients of L3-L5 segments and 7 patients of L4-S1 segments. The general conditions of operation, such as operation time, intraoperative blood loss, postoperative drainage was recorded. The visual analogue scale (VAS) for low back pain and Oswestry disability index (ODI) were compared in preoperatively and postoperatively(3 months, 12 months and last follow-up) between two groups. The change of range of motion (ROM) was observed by flexion and extension x-ray of lumbar. All patients successfully completed the operation. The follow-up time ranged from 22 to 34 months with an average of(26.8±5.6) months. The operative time (142.2±44.7) min and intraoperative blood loss(166.5±67.4)ml in PEEK group were lower than those in titanium group [(160.7±57.3) min、(212.8±85.4) ml](P<0.05). There was no significant differences in postoperative drainage between the two groups (P>0.05). At the final follow-up visit, in PEEK group and titanium group VAS of low back pain[(0.8±0.4) points vs (1.0±0.5) points], VAS for leg pain [ (0.7±0.4) points vs (0.8±0.5) points] and ODI [(9.8±1.6)% vs (12.1±1.5)%] were compared with preoperative [ (5.8±1.1) points vs (6.0±1.1)points], [ (7.2±1.7) points vs (7.0±1.6) points], [(68.5±8.9)% vs(66.3±8.2)%] were significantly different(P<0.05). There was no significant difference in VAS scores between the two groups at each postoperative time point (P>0.05). At 3 months after surgery, there was no difference in ODI between the two groups (P>0.05). There were significant differences in ODI between PEEK group and titanium rod group at 12 months [(15.5±2.1)% vs (18.4±2.4)%] and at the last follow-up [(9.8±1.6)% vs (12.1±1.5)%] (P<0.05). The total range of motion (ROM) of lumbar decreased in both groups after surgery. At 12 months after surgery and the last follow-up, the PEEK group compared with the titanium rod group, the total range of motion of lumbar was statistically significant (P<0.05). The range of motion (ROM) of the fixed segments decreased in both groups after surgery. The ROM of the fixed segments in PEEK group decreased from (9.5±4.6)° to (4.1±1.9)° at the last follow-up (P<0.05), which in the titanium rod group was decreased from (9.8±4.3)°to (0.9±0.5)° at the last follow-up (P<0.05). The range of motion (ROM) of upper adjacent segment increased in both groups, there was statistical significance in the ROM of upper adjacent segment between the two groups at 12 months after surgery and the last follow-up, (P<0.05). There was no screw loosening and broken rods in both groups during the follow-up period. The PEEK rod semi-rigid pedicle screw internal fixation system used in lumbar non-fusion surgery can retain part of the mobility of the fixed segment, showing comparable short-term clinical efficacy to titanium rod fusion. PEEK rod semi-rigid pedicle screw internal fixation system is a feasible choice for the treatment of lumbar spine degenerative diseases, and its long-term efficacy needs further follow-up observation.

Lumbar Pedicle Dimensions Using CT Scan in Adults of South-Eastern Nigeria as Related to Transpedicular Fixation.

Transpedicular fixation depends on accuracy of the entry points, angle of insertion and pedicular isthmus width for adequate screw insertion. Preoperative measurements of pedicle dimensions reduce the chances of failure during insertion. These pedicle dimensions (transverse diameter, longitudinal diameter, and maximum length of purchase [MLP]) vary with sex and race. Such data, from a large-scale study, are not available for our population. The study aims to evaluate the dimensions of pedicle that are relevant for pedicle screw fixation in Southeast Nigerian population. A prospective multi-slice CT based clinical anatomy study done at Memfys Hospital for Neurosurgery, Enugu. This study is on the lumbar pedicle dimensions that are related to transpedicular fixation (transverse and longitudinal diameters of the pedicle, MLP, pedicle transverse and longitudinal angles of inclination). Sample size (273) was calculated with the confidence interval formula based on the number of patients that present for images. Consent and ethical approval were obtained. The mean values are as follow: LD1 8.22 mm, LD2 7.73 mm, LD3 7.40 mm, LD4 7.16 mm, LD5 6.87 mm TD1 5.05 mm, TD2 5.31 mm, TD3 6.72 mm, TD4 8.27 mm, TD5 11.31 mm, MLP1 46.60 mm, MLP2 47.97 mm, MLP3 47.14 mm, MLP4 45.54 mm, MLP5 43.47 mm TA1 17.8°, TA2 19.34°, TA3 20.80°, TA4 22.00°, TA5 25.70° LA1 19.42°, LA2 18.61°, LA3 18.00°, LA4 17.09°, LA5 16.40°. Unlike transverse diameter, transverse angle, longitudinal dimension, longitudinal angle (LA), MLP there was significant correlation between age and mean LA. The mean values also correlated significantly with the gender. The mean values varied with the different vertebral levels and was good correlations between some of the parameters with age and gender.

Reply to "Concerning the Article Feasibility of C2 Pedicle Screw Fixation with the "in-out-in" Technique for Patients with Basilar Invagination".

Reply to "Concerning the Article Feasibility of C2 Pedicle Screw Fixation with the "in-out-in" Technique for Patients with Basilar Invagination".

Unilateral versus bilateral pedicle screw fixation with anterior lumbar interbody fusion: a comparison of postoperative outcomes.

To determine of the impact of ALIF with minimally invasive unilateral pedicle screw fixation (UPSF) versus bilateral pedicle screw fixation (BPSF) on perioperative outcomes, radiographic outcomes, and the rates of fusion, subsidence, and adjacent segment stenosis. All adult patients who underwent one-level ALIF with UPSF or BPSF at an academic institution between 2015 and 2022 were retrospectively identified. Postoperative outcomes including length of hospital stay (LOS), wound complications, readmissions, and revisions were determined. The rates of fusion, screw loosening, adjacent segment stenosis, and subsidence were assessed on one-year postoperative CT. Lumbar alignment including lumbar lordosis, L4-S1 lordosis, regional lordosis, pelvic tilt, pelvic incidence, and sacral slope were assessed on standing x-rays at preoperative, immediate postoperative, and final postoperative follow-up. Univariate and multivariate analysis compared outcomes across posterior fixation groups. A total of 60 patients were included (27 UPSF, 33 BPSF). Patients with UPSF were significantly younger (p = 0.011). Operative time was significantly greater in the BPSF group in univariate (p < 0.001) and multivariate analysis (ß=104.1, p < 0.001). Intraoperative blood loss, LOS, lordosis, pelvic parameters, fusion rate, subsidence, screw loosening, adjacent segment stenosis, and revision rate did not differ significantly between fixation groups. Though sacral slope (p = 0.037) was significantly greater in the BPSF group, fixation type was not a significant predictor on regression. ALIF with UPSF relative to BPSF predicted decreased operative time but was not a significant predictor of postoperative outcomes. ALIF with UPSF can be considered to increase operative efficiency without compromising construct stability.

Biomechanical Comparison of Corticopedicular Spine Fixation versus Pedicle Screw Fixation in a Lumbar Degenerative Spondylolisthesis Finite Element Analysis Model

To compare the stability of a corticopedicular posterior fixation (CPPF) device with traditional pedicle screws for decompression and fusion in adult degenerative lumbar spondylolisthesis. Finite element analysis (FEA) was used in a validated model of grade 1 L4-L5 spondylolisthesis to compare segmental stability after laminectomy alone, laminectomy with pedicle screw fixation, or laminectomy with CPPF device fixation. A 500-N follower load was applied to the model and different functional movements were simulated by applying a 7.5-Nm force in different directions. Outcomes included degrees of motion, tensile forces experienced in the CPPF device, and stresses in surrounding cortical bone. At maximum loading, laminectomy alone demonstrated a 1° increase in flexion range of motion, from 6.35° to 7.39°. Laminectomy with pedicle screw fixation and CPPF device fixation both reduced spinal segmental motion to ≤1° at maximum loading in all ranges of motion, including flexion (0.94° and 1.09°), extension (-0.85° and -1.08°), lateral bending (-0.56° and -0.96°), and torsion (0.63° and 0.91°), respectively. There was no significant difference in segmental stability between pedicle screw fixation and CPPF device fixation during maximum loading, with a difference of ≤0.4° in any range of motion. Tensile forces in the CPPF device remained ≤51% the ultimate load to failure (487 N) and stress in surrounding cortical bone remained ≤84% the ultimate stress of cortical bone (125.4 MPa) during maximum loading. CPFF fixation demonstrated similar segmental stability to traditional pedicle screw fixation whereas tensile forces and stress in surrounding cortical bone remained below the load to failure.

Novel MRI-Based Pedicle Bone Quality Score Independently Predicts Pedicle Screw Loosening after Degenerative Lumbar Fusion Surgery.

To introduce and evaluate an MRI-based PBQ score to determine its effectiveness in predicting pedicle screw loosening following lumbar fusion surgery. The retrospective study analyzed 244 patients who underwent posterior lumbar interbody fusion (PLIF) with pedicle screws between December 2017 and December 2021, with CT and MRI imaging before surgery. Data collected included patient demographics and preoperative radiological data. Radiographic screw loosening was measured at 12 months postoperatively. Clinical assessments included pain visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. The PBQ score was measured using MRI scans. We use univariate analysis for preliminary screening of the risk factors of screw loosening. Subsequent analysis involved multivariate logistic regression to identify independent predictive factors for screw loosening. We constructed the receiver operating characteristic (ROC) curve to ascertain the discriminative capacity of the PBQ score. The area under the curve (AUC) quantified its predictive accuracy. Additionally, we evaluated the association between PBQ score and screw loosening using Spearman's correlation analysis. Overall, 244 patients who underwent PLIF with pedicle screw fixation participated in this study, including 35 in the loosening group and 209 in the non-loosening group. PBQ score in the loosening group was significantly higher than that in the non-loosening group. On multivariate logistic regression, the higher PBQ score (OR = 8.481, 95% CI: 3.158-22.774; p < 0.001) and the lower mean Hounsfield unit (HU) value of L1-4 (OR = 0.967, 95% CI 0.951-0.984; p < 0.001) were the variables that significantly predicted screw loosening. The AUC for the PBQ score and HU value were 0.751 (95% CI: 0.673-0.828) and 0.702 (95% CI: 0.612-0.791). The PBQ score optimal cutoff to differentiate patients with loosening and with non-loosening was calculated as 3.045 with a sensitivity of 85.7% and specificity of 76.9%, while the optimal cutoff of the HU value was 151.5 with a sensitivity of 64.6% and specificity of 89.5%. The association between the PBQ score and the propensity for lumbar pedicle screw loosening was found to be substantial. As a predictive measure, the PBQ score outperformed the HU value in forecasting the likelihood of screw loosening post-posterior lumbar fusion.

A Prediction Nomogram for Fractured Vertebra Recollapse After Posterior Reduction and Pedicle Screw Fixation in Thoracolumbar Fractures

This study aimed to establish a predictive nomogram model for recollapse of fractured vertebra after posterior pedicle screw fixation in thoracolumbar fractures (TLFs). Patients undergoing posterior pedicle screw fixation for TLFs at our hospital between January 2016 and December 2021 were retrospectively reviewed. Patients were divided into 2 groups according to the presence or absence of recollapse of the fractured vertebra at the final follow-up. The predictors for fractured vertebra recollapse were identified by univariate and multivariable logistic regression analysis, and a nomogram model was developed. The prediction performance and internal validation were established. A total of 224 patients were included in this study. Of these, 46 (20.5%) patients developed recollapse of fractured vertebra. Age, thoracic and lumbar injury severity score, screw distribution in the fractured vertebra, and anterior vertebral height compression ratio were associated with vertebral recollapse. These predictors were used to construct a predictive nomogram. The area under the receiver operating characteristic curve of the nomogram model was 0.891. The concordance index was 0.891, and it was 0.877 with bootstrapping validation. The calibration curves and decision curve analysis also suggested that the nomogram model had excellent predictive performances for fractured vertebra recollapse. A clinical nomogram incorporating 4 variables was constructed to predict fractured vertebra recollapse after posterior pedicle screw fixation for TLFs. The nomogram demonstrated good calibration and discriminative abilities, which may help clinicians to make better treatment decisions.

Global trends and frontiers of research on Kümmell's disease: A bibliometric analysis.

The prevalence of Kümmell's disease (KD) has been increasing due to the aging population and the rise of osteoporotic vertebral compressibility fractures. As a result, there has been a growing concern about this condition. Despite the rapid advancements in its related research fields, the current research status and hotspot analysis of KD remain unclear. Therefore, our goal was to identify and analyze the global research trends on KD using bibliometric tools. All KD data were obtained from the Web of Science Core Collection. The information of research field was collected, including title, author, institutions, journals, countries, references, total citations, and years of publication for further analysis. From 1900 to 2022, a total of 195 articles and 1973 references have been published in this field, originating from 27 countries/regions and 90 journals, with China leading the contributions. The most significant institutional and author contributions come from Soochow University and Kim, HS, respectively. The journal with the highest number of published research and total citation frequency is Spine. The latest research focuses in this field include "risk factor," "osteoporotic vertebral compression fracture," "pedicle screw fixation," "percutaneous vertebroplasty," and "bone cement," and should be closely monitored. Additionally, we have conducted a comprehensive analysis of the 50 most-cited articles in KD, providing a valuable list of articles to guide clinical decision-making and future research for clinicians and researchers. In recent years, there has been a significant increase in scientific research on KD. Future research in KD is likely to focus on surgical treatment, risk factors, and complications.

Biomechanical Comparison Using 3-D Finite Element Method between Cortical Screw Trajectory Fixation and Pedicle Screw Fixation for Fusion of the Lumbar Degenerative Spine

Biomechanical Comparison Using 3-D Finite Element Method between Cortical Screw Trajectory Fixation and Pedicle Screw Fixation for Fusion of the Lumbar Degenerative Spine

Effective method of pedicle screw fixation in patients with neurologically intact thoracolumbar burst fractures: a systematic review of studies published over the last 20 years

ObjectiveTo conduct a systematic review of studies on various posterior pedicle screw fixation (PSF) methods used for treating neurologically intact thoracolumbar burst fractures and to identify the most effective and safe approaches. MethodsWe conducted a systematic review adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with the study registered in PROSPERO (CRD42024531093). The inclusion criteria were: (1) publication dates from January 1, 2004, to December 31, 2023; (2) availability of full-text articles in English; (3) thoracolumbar burst fractures without neurological deficits; (4) patients aged over 18; (5) reports on treatment outcomes or complications; (6) a mean follow-up period of at least 12 months. ResultsA total of 69 articles covering 116 patient groups were included. Our analysis highlighted the advantages of short-segment fixation without fusion over monosegmental, short-segment and long-segment fusion in terms of shorter operation times and reduced intraoperative blood loss (p = 0.001 and p < 0.001, respectively). Extensive fusion was associated with a significantly higher frequency of deep surgical site infections compared to other PSF methods (p = 0.043). Percutaneous pedicle screw fixation, applied to patients with lower body compression rates and kyphotic deformities, led to less potential for correction (p = 0.004), yet significantly decreased blood loss (p = 0.011), operation duration (p < 0.0001), and hospitalization duration (p < 0.0001). No significant benefits were observed with the use of additional intermediate screws in short-segment PSF. ConclusionsShort-segment pedicle screw fixation could be the optimal surgical treatment method for neurologically intact thoracolumbar burst fractures. The use of posterior lateral fusion in this context may increase the deep surgical site infection rate without reducing the frequency of implant-related complications or improving long-term treatment outcomes. The percutaneous approach remains the preferred technique; however, its limited reduction capabilities should be carefully considered during surgical planning for patients with severe kyphotic deformities. The application of intermediate screws in such patients has not demonstrated significant advantages. Removing the fixation system has not led to a significant decrease in implant-related complications or improvement in quality of life. The data obtained from the systematic review may assist surgeons in selecting the most appropriate surgical treatment method for patients with neurologically intact thoracolumbar burst fractures, thereby avoiding ineffective procedures and improving both short-term and long-term outcomes.

Ultrasound propagation characteristics within the bone tissue of miniature ultrasound probes: implications for the spinal navigation of pedicle screw placement.

The accuracy of pedicle screw fixation is crucial for patient safety. Traditional navigation methods based on computed tomography (CT) imaging have several limitations. Therefore, this study aimed to investigate the ultrasonic propagation characteristics of bone tissue and their relationship with CT imaging results, as well as the potential application of ultrasound navigation in pedicle screw fixation. The study used three bovine spine specimens (BSSs) and five human vertebral allograft bones (HABs) to progressively decrease the thickness of the cancellous bone layer, simulating the process of pedicle screw perforation. Five unfocused miniature ultrasound probes with frequencies of 2.2, 2.5, 3, 12, and 30 MHz were employed for investigating the ultrasonic propagation characteristics of cancellous and cortical bone through ultrasound transmission and backscatter experiments. The CT features of the bone tissue was obtained with the Skyscan 1174 micro-CT scanner (Bruker, Billerica, MA, USA). The experimental results demonstrated that low-frequency (2-3 MHz) ultrasound effectively penetrated the cancellous bone layer up to a depth of approximately 5 mm, with an attenuation coefficient below 10 dB/cm. Conversely, high-frequency (12 MHz) ultrasound exhibited significant signal attenuation in cancellous bone, reaching up to 55.8 dB/cm. The amplitude of the backscattered signal at the cancellous bone interface exhibited a negative correlation with the bone sample thickness (average r=-0.84), meaning that as the thickness of the cancellous bone layer on the cortical bone decreases, the backscattered signal amplitude gradually increases (P<0.05). Upon reaching the cortical bone interface, there was a rapid surge in echo signal amplitude, up to 8 times higher. Meanwhile, the statistical results indicated a significant correlation between the amplitude of the echo signal and the micro-CT scanning results of bone trabecular structure. Theoretically, using multiple ultrasonic probes (≥3) and regions of interest (ROIs) (≥5) has the potential to provide surgeons with early warning signals for pedicle perforation based on three or more successive increases in echo signal amplitude or a sudden substantial increase. The statistical results indicate a significant correlation between the amplitude of the echo signal and the micro-CT scanning results of bone trabeculae, suggesting the potential use of ultrasound as opposed to CT for real-time intraoperative bone navigation.

Computational study of a dorsolumbar complete burst fracture and its fixation methods

PurposeDuring a fall, a significant part of the major forces is absorbed by the dorsolumbar column area. When the applied stresses exceed the yield strength of the bone tissue, fractures can occur in the vertebrae. Vertebral fractures constitute one of the leading causes of trauma-related hospitalizations, accounting for 15% of all admissions. Posterior pedicle screw fixation has become a common method for treating burst fractures. However, physicians remain divided on the number of fixed segments that are needed to improve clinical outcomes. The present work aims to understand the biomechanical impact of different fixation methods, improving surgical treatments.Design/methodology/approachA finite element model of the dorsolumbar spine (T11–L3) section, including cartilages, discs and ligaments, was created. The dorsolumbar stability was tested by comparing two different surgical orthopedic treatments for a fractured first lumbar vertebra on the L1 vertebra: the posterior short segment fixation with intermediate screws (PSS) and the posterior long segment fixation (PL). Distinct loads were applied to represent daily activities.FindingsResults show that both procedures provide acceptable segment fixation, with the PL offering less freedom of movement, making it more stable than the PSS. The PL approach can be the best choice for an unstable fracture as it leads to a stiffer spine segment.Originality/valueThis study introduces a novel computational model designed for the biomechanical analysis of dorsolumbar injuries, aiming to identify the optimal treatment approaches within both clinical and surgical contexts.