Rate Of Facet Joint Violation Research Articles

Comparison of minimally invasive transforaminal lumbar interbody fusion and midline lumbar interbody fusion in patients with spondylolisthesis

BackgroundThis study aimed to compare surgical outcomes, clinical outcomes, and complications between minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) and midline lumbar interbody fusion (MIDLIF) in patients with spondylolisthesis.MethodsThis study retrospectively compared the patients who underwent MIS TLIF (n = 37) or MIDLIF (n = 50) for spinal spondylolisthesis. Data of surgical outcomes (postoperative one-year fusion rate and time to bony fusion), clinical outcomes (visual analog scale [VAS] for pain and Oswestry Disability Index [ODI] for spine function), and complications were collected and analyzed.ResultsThere was more 2-level fusion in MIDLIF (46% vs. 24.3%, p = 0.038). The MIS TLIF and MIDLIF groups had similar one-year fusion rate and time to fusion. The MIDLIF group had significantly lower VAS at postoperative 3-months (2.2 vs. 3.1, p = 0.002) and postoperative 1-year (1.1 vs. 2.1, p = < 0.001). ODI was not significantly different. The operation time was shorter in MIDLIF (166.1 min vs. 196.2 min, p = 0.014). The facet joint violation is higher in MIS TLIF (21.6% vs. 2%, p = 0.009). The other complications were not significantly different including rate of implant removal, revision, and adjacent segment disease.ConclusionIn this study, postoperative VAS, operation time, and the rate of facet joint violation were significantly higher in the MIS TLIF group. Comparable outcomes were observed between MIDLIF and MIS TLIF in terms of fusion rate, time to fusion, and postoperative ODI score.

Comparison of the S8 navigation system and the TINAVI orthopaedic robot in the treatment of upper cervical instability.

The objective isto compare the clinical efficacy and safety of the S8 navigation system and the Tinavi orthopaedic surgery robot in the treatment of upper cervical instability. The research methods adopted are as follows. The clinical data of patients with upper cervical instability who underwent surgery from May 2021 to December 2021 were analysed retrospectively. Patients were divided into a navigation group (assisted by the S8 navigation system) and a tinavi group (assisted by the Tinavi robot) according to the auxiliary system used. Computed tomography and digital radiography were performed after the operation. The accuracy of pedicle screw placement was evaluated using the criteria put forward by Rampersaud. Degree of facet joint violation, visual analogue scale score, neck disability index and Japanese orthopaedic association score were recorded and assessed during follow-up examinations in both groups. Record two groups of surgery-related indicators. Record the complications of the two groups. A total of 50 patients were included. 21 patients in the navigation group and 29 in the tinavi group. The results of the study are as follows.The average follow-up time was 12.1months. There was no significant difference in nail placement accuracy between the navigation and tinavi groups (P > 0.05); however, the navigation group had a significantly higher rate of facet joint violation than that of tinavi group (P < 0.05), and the screws were placed closer to the anterior cortex (P < 0.05). Significantly more intraoperative fluoroscopies were performed in the tinavi group than in the navigation group, and the operation time was significantly longer in the tinavi group than in the navigation group (P < 0.05). The time of single nail implantation, intraoperative blood loss and incision length in navigation group were significantly longer than those in tinavi group. There were no statistically significant differences in other indicators between the two groups (P > 0.05). We come to the following conclusion.The Stealth Station S8 navigation system (Medtronic, USA), which also uses an optical tracking system, and the Tinavi Orthopedic robot have shown the same high accuracy and satisfactory clinical results in the treatment of upper cervical instability. Although the S8 navigation system still has many limitations, it still has good application prospects and is a new tool for spine surgery.

Comparing Three-dimensional and Two-dimensional Preoperative Planning for Lumbar Transpedicular Screw Placement: A Retrospective Study.

Transpedicular screw (TPS) misplacement is still a nightmare for spine surgeons. Preoperative planning is one of the methods that a surgeon could use to minimize this complication. This study aims to compare the efficacy of three-dimensional (3D) and two-dimensional (2D) preoperative planning in posterior lumbar TPSs placement performed using the freehand technique. Patients who underwent posterior TPSs placement for degenerative lumbar spondylolisthesis or spinal stenosis using the freehand technique between November 2021 and October 2022 were evaluated retrospectively. In total, 33 and 30 patients who met the inclusion criteria were consecutively operated on with preoperative 2D and 3D planning, respectively. The patients were divided into the 2D preoperative planning group (2DG) and 3D preoperative planning group (3DG) and the two groups were compared. Sixty-three patients were operated during the study period. There was no significant difference between the groups regarding blood transfusion, operation time, and radiation exposure. Although the accuracy of TPSs positioning was 94.2 and 96.5% in the 2DG and 3DG, respectively, the difference between the groups was not statistically significant. The upper facet joint violation rate was 12.8% (n = 20) in the 2DG versus 3.5% (n = 5) in the 3DG (p = 0.006). All L4 TPSs were inserted with their standard entry points without any modification (p < 0.0001; relative/risk ratio = 0.64). The modification rate was higher in L1, L2, and L5 TPSs (p < 0.0001; χ 2 = 24.7). For patients with degenerative lumbar diseases, 3D preoperative planning in posterior lumbar instrumentation surgeries performed with the freehand technique decreased the upper facet joint violation rate.

Comparison of screw placement guided by O-arm navigation and ultrasound volume navigation in minimally invasive transforaminal lumbar interbody fusion

To compare the effectiveness of O-arm navigation and ultrasound volume navigation (UVN) in guiding screw placement during minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery. Sixty patients who underwent MIS-TLIF surgery for lumbar disc herniation between June 2022 and June 2023 and met the selection criteria were included in the study. They were randomly assigned to group A (screw placement guided by UVN during MIS-TLIF) or group B (screw placement guided by O-arm navigation during MIS-TLIF), with 30 cases in each group. There was no significant difference in baseline data, including gender, age, body mass index, and surgical segment, between the two groups ( P>0.05). Intraoperative data, including average single screw placement time, total radiation dose, and average single screw effective radiation dose, were recorded and calculated. Postoperatively, X-ray film and CT scans were performed at 10 days to evaluate screw placement accuracy and assess facet joint violation. Pearson correlation and Spearman correlation analyses were used to observe the relationship between the studied parameters (average single screw placement time and screw placement accuracy grading) and BMI. The average single screw placement time in group B was significantly shorter than that in group A, and the total radiation dose of single segment and multi-segment and the average single screw effective radiation dose in group B were significantly higher than those in group A ( P<0.05). There was no significant difference in the total radiation dose between single segment and multiple segments in group B ( P>0.05), while the total radiation dose of multiple segments was significantly higher than that of single segment in group A ( P<0.05). No significant difference was found in the accuracy of screw implantation between the two groups ( P>0.05). In both groups, the grade 1 and grade 2 screws broke through the outer wall of the pedicle, and no screw broke through the inner wall of the pedicle. There was no significant difference in the rate of facet joint violation between the two groups ( P>0.05). In group A, both the average single screw placement time and screw placement accuracy grading were positively correlated with BMI ( r=0.677, P<0.001; r=0.222, P=0.012), while in group B, neither of them was correlated with BMI ( r=0.224, P=0.233; r=0.034, P=0.697). UVN-guided screw placement in MIS-TLIF surgery demonstrates comparable efficiency, visualization, and accuracy to O-arm navigation, while significantly reducing radiation exposure. However, it may be influenced by factors such as obesity, which poses certain limitations.

Influence of the facet joint angle on facet joint degeneration following pedicle screw fixation without fusion in thoracolumbar fractures.

Posterior approach pedicle screw fixation without fusion is widely used in the treatment of neurologically intact type A3 thoracolumbar fractures. To analyze the influence of the facet joint (FJ) angle on FJ degeneration following posterior approach pedicle screw fixation without fusion in neurologically intact type A3 thoracolumbar fractures. Fifty-eight patients who underwent pedicle screw fixation via the traditional posterior approach (n= 28) or the Wiltse approach (n= 30) were enrolled. A CT scan was performed before fixation and before fixation removal (Within 1.5 to 2 years after fixation) to evaluate the FJs parameters, including FJ inclination (FJI), FJ tropism (FJT), FJ violation, and FJ degeneration grade (FJDG), of three fixed segments and the adjacent segment below the fixed segments. There was no significant difference in FJ violation rate, FJDG deterioration, or FJ angle between the two groups (P> 0.05). FJDG deterioration showed a weak positive correlation with FJI and FJT before fixation, and the angular change in FJI (P< 0.05); and FJT before fixation and the angular change in FJI were risk factors for FJDG deterioration (P< 0.01). The Wiltse approach did not increase the rate of FJDG deterioration and FJs angle changes. However, the FJT before fixation and the angular change in FJI were risk factors for FJDG deterioration.

Ultrasound-guided Jamshidi needle puncture to reduce radiation exposure during percutaneous pedicle screw placement: study protocol for a randomised controlled trial

IntroductionPercutaneous pedicle screw placement (PPSP) is a minimally invasive procedure highly dependent on fluoroscopic guidance, which results in increased radiation exposure and prolonged operative time. Ultrasound can image the lumbar...

Superior facet joint violation between open and minimally invasive techniques in lumbar fusion surgery: An updated systematic review and meta-analysis.

Superior facet joint violation (FJV) is a potential risk factor for adjacent segment disease following lumbar fusion surgery. We sought to conduct a systematic review and meta-analysis to compare screw-related superior FJV rates between the open and different minimally invasive (MI) techniques-fluoroscopy-based, 3D-image navigation, and navigation with robotic assistance-in adult lumbar fusion surgery. We searched original articles comparing the rates of screw-related FJV between the open and different MI techniques in adult lumbar fusion surgery for lumbar degenerative diseases in PubMed, EMBASE, and the Cochrane Library from inception to September 2021. We compared the numbers of top-level pedicle screws and associated superior FJVs in the main analyses and performed subgroup analysis based on different MI techniques to examine whether individual MI approaches differed in superior FJV rate. Risk ratio (RR) and 95% confidence interval (CI) were calculated in a random-effect meta-analysis. Included in the meta-analysis were 16 articles with 2655 patients and 4638 top-level pedicle screws. The pooled analysis showed no significant difference in superior FJV rates between the MI and open groups (RR: 0.89, 95% CI: 0.62-1.28). The subgroup analysis demonstrated that the overall rates of superior FJV were 27.1% (411/1518) for fluoroscopy-based, 7.1% (43/603) for 3D-image navigation, and 3.2% (7/216) for navigation with robotic assistance. Compared with the open method, the overall RRs were 1.53 (95% CI: 1.19-1.96) for fluoroscopy-based, 0.41 (95% CI: 0.22-0.75) for 3D-image navigation, and 0.25 (95% CI: 0.08-0.72) for navigation with robotic assistance. Among the three common MI techniques, fluoroscopy-based can be associated with a higher risk of superior FJV, while both 3D-image navigation and navigation with robotic assistance may be associated with lower risks as compared with the open method. Considering the limitations of the study, more trials are needed to prove these clinical findings.

Incidence and risk factors associated with superior-segmented facet joint violation during minimal invasive lumbar interbody fusion

BACKGROUND CONTEXTThe trend of minimally invasive lumbar interbody fusion is increasing, and adjacent segmental degeneration (ASD) is one of the complications of the procedures in which facet joint violation (FJV) is a cause. FJVs can occur during percutaneous instrumentation. This study aimed to identify the risk factors that affect FJV during minimally invasive lumbar interbody fusion. PURPOSETo identify the risk factors for FJVs and the factors that have a strong impact on the violation. STUDY DESIGNRetrospective study. PATIENT SAMPLEPatients who underwent minimally invasive lumbar interbody fusion with percutaneous screw fixation between June 2018 and December 2019. OUTCOME MEASURESPrevalence of the FJV was reviewed by CT scans which obtained within 6 months after surgery, and the axial, coronal, and sagittal cuts of the scans were evaluated. The FJV was defined as the screw being visible in the facet joint in at least one plane of the CT scan. Radiographic parameters were measured using CT scans including diameters of the facet joints in the axial, coronal, and sagittal planes defined by the facet diameter. The facet angle (FA), the pedicle angle (PA), the screw-facet angle (SFA), the screw-endplate angle (SEA), and the superior margin of the facet joint in the sagittal plane (SD) differed from the head of the screw. At Last, the depth of back muscle was measured in the axial cut of the MRI. METHODSThis study analyzed 119 patients who underwent minimally invasive lumbar interbody fusion between June 2018 and December 2019. Facet joint violation at the uppermost level was examined using CT in all dimensions. Radiographic parameters (facet diameter, facet angle, pedicle angle, screw-facet angle, screw-endplate angle, and distance between the head of the screws and the facet) were measured. BMI, age, diagnosis, and navigation assistance were included in the study. Risk factors were analyzed to determine which factors had an effect on FJV, and the cut-off was calculated for each parameter. RESULTSThis study included 119 patients, with a mean age of 63 years. FJV occurred in 13/119 (10.9%) patients and 15/238 (6.3%) joints, respectively. No FJV occurred in 120 joints operated with navigation-assistance and 15/178 (8.4%) joints operated without navigation (p=.01). We found an increasing proportion of violations at more caudal levels: no violations occurred in eight patients with lumbar at L1 or L2, and 1/40 (2.5%), 7/158 (4.4%), and 7/32 (21.9%) of violations occurred at L3, L4, and L5, respectively (p=.01). The diameter of the facet in the axial cut, facet angle, screw facet angle, and distance between the head of the screw and facet were statistically significant in determining the increasing rate of FJV after multivariate analysis was performed (AROC=0.9486, p≤.05). The cutoff point for each radiographic parameter were diameter of facet in the axial ≥17.5 mm, diameter of facet in coronal plane ≥19.5 mm, facet angle ≥41.5o, screw-facet angle ≥39o, and distance between facet and the screw ≥-2.6 mm. The estimated probability of FJV was 96.9% when every parameter was greater than the cut-off point. CONCLUSIONSAn increase in the facet diameter in the axial plane, coronal plane, facet angle, screw facet angle, and the distance between the dome of the screw and facet are risk factors for FJV. Surgeons can avoid violations when radiographic considerations are done. Careful screw placement and good entry points for instrumentation may decrease the rate of facet violation.

Comparison of adjacent segment disease after minimally invasive versus open lumbar fusion: a minimum 10-year follow-up.

The object of this study was to compare, after a long-term follow-up, the incidence and features of adjacent segment disease (ASDis) following lumbar fusion surgery performed via an open technique using conventional interbody fusion plus transpedicular screw fixation or a minimally invasive surgery (MIS) using a tubular retractor together with percutaneous pedicle screw fixation. The authors conducted a retrospective chart review of patients with a follow-up period > 10 years who had undergone instrumented lumbar fusion at the L4-5 level between January 2004 and December 2010. The patients were divided into an open surgery group and MIS group based on the surgical method performed. Baseline characteristics and radiological findings, including factors related to ASDis, were compared between the two groups. Additionally, the incidence of ASDis and related details, including diagnosis, time to diagnosis, and treatment, were analyzed. Among 119 patients who had undergone lumbar fusion at the L4-5 level in the study period, 32 were excluded according to the exclusion criteria. The remaining 87 patients were included as the final study cohort and were divided into an open group (n = 44) and MIS group (n = 43). The mean follow-up period was 10.50 (range 10.0-14.0) years in the open group and 10.16 (range 10.0-13.0) years in the MIS group. The overall facet joint violation rate was significantly higher in the open group than in the MIS group (54.5% vs 30.2%, p = 0.022). However, in terms of adjacent segment degeneration, there were no significant differences in corrected disc height, segmental angle, range of motion, or degree of listhesis of the adjacent segments between the two groups during follow-up. The overall incidence of ASDis was 33.3%, with incidences of 31.8% in the open group and 34.9% in the MIS group, showing no significant difference between the two groups (p = 0.822). Additionally, detailed diagnosis and treatment factors were not different between the two groups. After a minimum 10-year follow-up, the incidence of ASDis did not differ significantly between patients who had undergone open fusion and those who had undergone MIS fusion at the L4-5 level.

Comparison of facet joint violation in lumbar posterior spinal instrumentation using different techniques including cortical bone trajectory

Study background: A retrospective study to compare the rate of facet joint violation (FJV) in lumbar posterior spinal instrumentation using open pedicle screw, percutaneous pedicle screw, and cortical bone trajectory (CBT) technique. CBT is a new posterior spinal instrumentation technique in which a more caudal entry point can minimize iatrogenic damage to the cranial facet joint. Only one recent study reports incidence of FJV of 11%; however, no previous reports comment on radiological outcomes comparing to traditional open and percutaneous screws. Methods: We reviewed 90 patients who underwent lumbar posterior spinal instrumentation from January 2016 to June 2017. Postoperative computer tomography scans were performed to evaluate FJV. Incidence of FJV was graded by three reviewers according to Seo classification. Results: Totally, 446 screws (open 43.4%, percutaneous 37.8%, CBT 18.9%) were inserted. Among these, 6.3% (28/446) had screw head or rod in contact with facet joint and 0.9% (4/446) had screws directly invaded the facet joint. Overall, FJV was 7.2% (CTB = 3.4%, open = 10.4%, and percutaneous = 4.5%, p = 0.075). Conclusion: CBT technique has potential advantage in reducing FJV. It has a unique entry site at lateral aspect of pars interarticular with a caudomedial to craniolateral pathway. It is a reasonable alternative to open or percutaneous techniques in lumbar posterior spinal instrumentation.

Facet angle and its importance on joint violation in percutaneous pedicle screw fixation in lumbar vertebrae: A retrospective study.

This is a retrospective study of case records. The aim of this study was to investigate the relationship between the facet angle (FA) at the pedicle level and facet joint violation (FJV) in percutaneous pedicle screw fixation (PPSF) in lumbar vertebrae.Current PPSF technique has a high facet violation rate than open surgery, and the relationship of FJV and FA has not been studied.Retrospective imaging analysis was conducted for 115 cases who underwent PPSF from December 2013 to November 2016 by the same group of surgeons using the same technique, in the spine surgery center of our hospital. The FA at the pedicle level was measured by computed tomography, and diagnosis and evaluation of FJV grade were performed postoperatively. The effect of the variant FA and lumbar segment (L1-L5) on FJV, and the correlation between FA and the FJV and FJV grade in PPSF were evaluated.A total of 476 percutaneous pedicle screws were included: 144 L1, 136 L2, 64 L3, 72 L4, and 60 L5 screws, with a total FJV rate of 30.46% (145/476). The FJV rate was 28.78% in upper lumbar group with 344 screws (99/344), and 34.85% in lower lumbar group with 132 screws (46/132). There was no significant difference between groups with regards to FJV rate, and age, sex, or BMI index. Evaluation of variant FA and lumbar segment on FJV rate indicated that FJV rate increased dramatically when FA >35 degree; however, FJV rate was not significantly related to the lumbar segment. There was a positive correlation between FA and FJV rate, as well as FA and FJV grade.There was a positive correlation between the increase of the FA at the pedicle level, and the FJV rate and FJV grade. The FJV risk increased remarkably when the FA was >35 degree.

Percutaneous pedicle screw placements: accuracy and rates of cranial facet joint violation using conventional fluoroscopy compared with intraoperative three-dimensional computed tomography computer navigation.

The goal of this study was to compare the accuracy and cranial facet joint violation rates between percutaneous pedicle screw placements using conventional fluoroscopy and intraoperative 3-D CT (O-arm) computer navigation. We reviewed 194 pedicle screw of 28 consecutive patients who underwent minimally invasive lumbar or thoracic spinal stabilization. The accuracy of screw placement was evaluated according to two criteria published by Neo et al. and Upendra et al. Facet joint violation was evaluated according to the classification described by Babu et al. Upon Neo grading, CFT group had 19.4% (14/72) pedicle breach rate and CT-IGN group had a 5.7% (7/122) pedicle breach rate (p<0.005). The same sets of screws were also assessed using the outcome-based classification established by Upendra. There were no screw caused neurovascular injuries (type 3=0) in both groups. The results showed that 87.5% (63/72) screws had acceptable placements (type I) and 12.5% (9/72) had unacceptable placements (type II) in CFT group. In contrast, 94.3% (115/122) screw had acceptable placements (type I) and only 5.7% (7/122) had unacceptable placements (type II) in CT-IGN group. Additionally, CFT group had a significantly higher facet joint violation rate of 30.5% (11/36) than CT-IGN group that had a 3.8% (3/79) violation rate (p<0.005). This study indicated the use of intraoperative CT imaging (O-arm) navigation in PPS placement have very beneficial implications for MIS.

Influencing factors of adjacent superior segment facet joint violation after transpedicular screw instrumentation during transforanal lumbar interbody fusion

To explore the influencing factors of pedicle screw instrumentation and provide theoretical rationales for decreasing facet joint violation rate by radiological evaluations of superior-segment facet joint violation after pedicle screw instrumentation in transforaminal lumbar interbody fusion (TLIF). A retrospective study was conducted for 101 patients undergoing lumbar fusion after failed conservative treatment between December 2011 and December 2013. According to the Seo classification, computed tomography was used for evaluating the position of pedicle screw with superior segment facet joint. And χ2 test was used to examine the associations between superior segment facet joint violation and gender, age, construct level, fusion length and transpedicular screw side. A total of 202 screws were evaluated. There were grade 0 (n =154, 76.2%), grade 1 (n = 43, 21.3%) and grade 2 (n = 5, 2.5%). In all screws, facet joint violation occurred in L5 segment more frequently than in any other segment (P < 0.05), left-side facet joint violation was more common than right-side one (P < 0.05). No statistical associations existed between violation rates and gender, age and fusion length. During TLIF, there is a higher incidence of facet joint violation at right side and in L5 segment compared with other lumbar segments.

Comparison of cranial facet joint violation rate between percutaneous and open pedicle screw placement: a systematic review and meta-analysis.

Percutaneous and open pedicle screw placements have been widely used in lumbar fusion surgery. However, there are conflicting reports of cranial facet joint violation rate for the 2 techniques.To better determine the rate of cranial facet joint violation, a systematic review and meta-analysis was performed in the present study.We searched the established electronic literature databases including MEDLINE, EMBASE, World of Science, and the Cochrane Central Register of Controlled Trials databases for trials involving the 2 pedicle screw placement techniques. Odds ratio (OR) and 95% confidence interval (CI) were calculated.Four comparative trials with a cumulative sample size of 881 patients and 1755 cranial pedicle screws were identified and analyzed. The results showed that cranial facet joint violation rate was 18.18% (154/847) in percutaneous group and 18.72% (170/908) in open group. The pooled data revealed that there was no significant difference in the violation rate (OR 0.75, 95% CI 0.24–2.30, P = 0.62). In addition, there was also no significant difference for the rate of severe violation between the 2 techniques (OR 1.20, 95% CI 0.55–2.62, P = 0.64, random effect model).Based on the current data, the meta-analysis shows that similar cranial facet joint violation rate occurs during the percutaneous and open pedicle screw placement techniques. In addition, taking the limitations of this study into consideration, it was still not appropriate to draw such a strong conclusion. More well-designed prospective randomized controlled trials are needed to assess violation rate for the 2 techniques in the future.

Comparison of Cranial Facet Joint Violation Rates Between Open and Percutaneous Pedicle Screw Placement Using Intraoperative 3-D CT (O-arm) Computer Navigation

Retrospective study comparing cranial facet joint violation rates of open and percutaneous pedicle screws inserted using 3-dimensional image-guidance. To determine the rate of cranial facet joint violation in intraoperative computed tomography (CT) image-guided lumbar pedicle screw instrumentation and compare facet joint violation rates between CT image-guided open and percutaneous techniques. Facet joint violation by pedicle screws can potentially result in a higher rate of adjacent segment degeneration. Reported cranial facet joint violation rates range from 7% to 100%. Intraoperative image-guidance, which has enhanced pedicle screw placement accuracy, may aid in avoiding impingement of the cranial facet joints. We reviewed 188 cases of 3-dimensional image-guided lumbar pedicle screw instrumentation from November 2006 to December 2011. The cranial screws of each construct were graded by 3 reviewers according to the Seo classification (0 = no impingement; 1 = screw head in contact/suspected to be in contact with joint; 2 = screw clearly invaded the joint) on intraoperative axial CT images. If there was a difference in evaluation, a consensus was reached to arrive at a single grade. The χ2 test was used to determine significance between the open and percutaneous group (α = 0.05). A total of 370 screws (245 open, 125 percutaneous) were graded. Overall facet joint violation rate was 18.9% (grade 1 = 16.2%, grade 2 = 2.7%). Open technique (grade 1 = 22.4%, grade 2 = 4.1%) had a significantly higher violation rate than percutaneous technique (grade 1 = 4%, grade 2 = 0%) (P < 0.0001). There is a trend of an increasing likelihood of facet joint violation from L1 to L5. The use of intraoperative CT image-guidance in lumbar pedicle screw placement resulted in a facet joint violation rate at the lower end of the reported range in literature. The percutaneous technique has a significantly lower facet violation rate than the open technique. 4.