Postoperative Computed Tomography Scans Research Articles

Surgical approach of T-type acetabular fractures does not affect quality of reduction on postoperative CT or the likelihood of postoperative complications

IntroductionT-type acetabular fractures are rare but challenging injuries. The purpose of this study was to evaluate for associations between chosen surgical approach for T-type acetabular fracture fixation, reduction quality, and complications. MethodsRetrospective, single institution study of T-type acetabular fractures who underwent surgical fixation. Surgical interventions included open reduction and internal fixation (ORIF) through an anterior intrapelvic approach (AIP) (modified Rives-Stoppa) and/or posterior (Kocher-Langenbeck [KL]), or percutaneous screw fixation. The primary outcome was reduction quality on routine postoperative computed tomography (CT) scan and postoperative complications. ResultsDuring the study period (March 2016 – October 2022), 22 patients presented with T-type acetabular fractures. Surgical approaches included AIP [31.8% (7/22)], percutaneous [27.3% (6/22)], AIP+KL [22.7% (5/22)], and KL [18.2% (4/22)]. On CT scans, 9.0% (2/22) had anatomic reductions, 27.2% (6/22) had fair reductions, and 63.6% (14/22) had poor reductions based on Matta Reduction Criteria. There was no observed difference in reduction quality between surgical approaches. Poor reductions (> 3 mm) were not associated with surgical approach, fracture classification, unstable pelvic ring injuries, posterior wall fractures, T-stem component, transverse component, preoperative articular displacement, preoperative femoral head protrusion, or surgeon experience. Complications occurred in 50.0% (11/22) of patients. No observed difference in complication rates was noted between the surgical approaches. ConclusionT-type acetabular fractures are challenging injuries with few patients achieving anatomic reduction on postoperative CT scans and half of patients developing complications.

Robotics Coupled With Navigation for Pediatric Spine Surgery: Initial Intraoperative Experience With 162 Cases.

This study assesses intraoperative efficacy, accuracy, and complications of pedicle screw placement using robotic-assisted navigation (RAN) in pediatric spine surgery. A retrospective review of patients who underwent spine deformity surgery using RAN at a single pediatric institution from 2019 to 2021 was conducted. Patient demographics, perioperative metrics, screw execution and accuracy, technical difficulties, and other outcomes were summarized. In cases with postoperative computed tomography scans, screws were classified using the Gertzbein and Robbins classification scale. Fisher exact tests were used to assess the relationship between procedural changes and lateral screw malposition. One hundred sixty-two cases with an average patient age of 15.1 years (range, 4 to 31y) were reviewed. The most common diagnosis was adolescent idiopathic scoliosis (n=80) with an average major curve of 65 degrees. Of 1467 screws attempted, 1461 were executed successfully (99.6%). All failures were in Type D pedicles and were lateral deviations recognized with routine intraoperative fluoroscopy. In cases with postoperative computed tomography imaging, 100% of screws (n=197) were placed with complete containment (Grade A). Remaining screws were graded as accurate by mirroring fluoroscopy and planned computer software positions. In 4% of cases, loss of registration was detected by a safety check before drilling at the planned level. There were no neurological deficits or returns to the operating room. Two changes occurred as part of the learning curve associated with this technique. (1) Adoption of a high-speed navigated drill: Change 1 (last 74 cases). (2) Drilling all pilot holes robotically first, then placing screws within the robotically established tracts to avoid motion and subsequent registration disruption: Change 2 (last 39 cases). Change 1 was less likely to result in screw malposition as no screws skived lateral with the technique ( P =0.03). Change 2 trended toward statistical significance for avoidance of screw malposition and loss of registration, as no loss of registration occurred after adopting this technique. This study highlights the safety and screw accuracy associated with the use of RAN in pediatric patients. Level III.

Accuracy Evaluation of a Novel Spinal Robotic System for Autonomous Laminectomy in Thoracic and Lumbar Vertebrae: A Cadaveric Study.

The main function of robots in spine surgery is to assist with pedicle screw placement. Laminectomy, which is as important as pedicle screw placement, lacks a mature robot-assisted system. The aims of this study were to introduce the first autonomous laminectomy robot, to explore the feasibility of autonomous robotic laminectomy, and to validate its accuracy using a cadaveric model. Forty vertebrae from 4 cadavers were included in the study; 7 thoracic and 3 lumbar vertebrae were randomly selected in each cadaver. The surgeon was able to plan the laminectomy path based on computed tomographic (CT) data before the surgical procedure. The robot performed the laminectomy autonomously, and a postoperative CT scan was made. The deviation of each cutting plane from the plan was quantitatively analyzed, and the accuracy and safety were qualitatively evaluated. The time required for the laminectomy was also recorded. Cuts were performed in 80 laminectomy planes (56 for thoracic vertebrae and 24 for lumbar vertebrae). The mean time for 1-sided laminectomy was 333.59 ± 116.49 seconds, which was shorter for thoracic vertebrae (284.41 ± 66.04 seconds) than lumbar vertebrae (448.33 ± 128.65 seconds) (p < 0.001). The mean time for single-level total laminectomy was 814.05 ± 302.23 seconds, which was also shorter for thoracic vertebrae (690.46 ± 165.74 seconds) than lumbar vertebrae (1,102.42 ± 356.13 seconds) (p = 0.002). The mean deviation of the cutting plane from the plan was 0.67 ± 0.30 mm for the most superior cutting point and 0.73 ± 0.31 mm for the most inferior point. There were no significant differences in the deviation between thoracic vertebrae (0.66 ± 0.26 mm) and lumbar vertebrae (0.67 ± 0.38 mm) at the superior cutting point (p = 0.908) and between thoracic vertebrae (0.72 ± 0.30 mm) and lumbar vertebrae (0.73 ± 0.33 mm) at the inferior cutting point (p = 0.923). In the qualitative analysis of the accuracy of the 80 laminectomy planes, 66 (83%) were classified as grade A, 14 (18%) were grade B, and none was grade C. In the safety analysis, 65 planes (81%) were considered safe and the safety of the other 15 planes (19%) was considered uncertain. The results confirmed the accuracy of this robotic system, supporting its use for laminectomy of thoracolumbar vertebrae. Therapeutic Level V . See Instructions for Authors for a complete description of levels of evidence.

Reintervention of Residual Aortic Dissection after Type A Aortic Repair: Results of a Prospective Follow-Up at 5 Years.

Background After a type A aortic dissection repair, a patent false lumen in the descending aorta is the most common situation encountered, and is a well-known risk factor for aortic growth, reinterventions and mortality. The aim of this study was to analyze the long-term results of residual aortic dissection (RAD) at a high-volume aortic center with prospective follow-up. Methods In this prospective single-center study, all patients operated for type A aortic dissection between January 2017 and December 2022 were included. Patients without postoperative computed tomography scans or during follow-up at our center, and patients without RAD were excluded. The primary endpoint was all-cause mortality during follow-up for patients with RAD. The secondary endpoints were perioperative mortality, rate of distal aneurysmal evolution, location of distal aneurysmal evolution, rate of distal reinterventions, outcomes of distal reinterventions, and aortic-related death during follow-up. Results In total, 200 survivors of RAD comprised the study group. After a mean follow-up of 27.2 months (1-66), eight patients (4.0%) died and 107 (53.5%) had an aneurysmal progression. The rate of distal reintervention was 19.5% (39/200), for malperfusion syndrome in seven cases (3.5%) and aneurysmal evolution in 32 cases (16.0%). Most reinterventions occurred during the first 2 years (82.1%). Twenty-seven patients were treated for an aneurysmal evolution of RAD including aortic arch with hybrid repair in 21 cases and branched aortic arch endoprosthesis in six cases. In the hybrid repair group, there was no death, and the rate of morbidity was 28.6% (6/21) (one minor stroke, one pulmonary complication, one recurrent paralysis with complete recovery and three major bleeding events). In the branched endograft group, there was no death, no stroke, and no paraplegia. There was one case (16.7%) of carotid dissection. Complete aortic remodeling or complete FL thrombosis on the thoracic aorta was found in 18 cases (85.7%) and in five cases (83.3%) in the hybrid and branched endograft groups, respectively. Conclusions: Despite a critical course in most cases of RAD, with a high rate of aneurysmal evolution and reintervention, the long-term mortality rate remains low with a close follow-up and a multidisciplinary management in an expert center.

Evaluation of pure subarachnoid hemorrhage after mechanical thrombectomy in a series of 781 consecutive patients.

Subarachnoid hyperdensity is commonly seen on postoperative computed tomography scans within 24 h after mechanical thrombectomy. The impact on patients' outcomes remains uncertain. We present a real-world experience evaluating periprocedural factors associated with the development of subarachnoid hemorrhage (SAH) and its impact on outcomes of patients with acute stroke undergoing mechanical thrombectomy. A single-center, retrospective analysis was performed between January 2016 and August 2021, including all consecutive patients who underwent thrombectomy. Our study aimed to evaluate periprocedural factors associated with subarachnoid hemorrhage within 24 h of the intervention, and the potential impact on patients' outcome. Of 781 patients, 44 patients (5.63%) demonstrated pure SAH within 24 h of the intervention. Patients from the SAH group were more likely to have tandem occlusion (15.9% vs. 5.2%, p = .003), aspiration using reperfusion pump system (81.4% vs. 66.8%, p = .047), intraoperative complications (9.1% vs. 0.9%; p < .001), longer puncture-to-recanalization times (45 min vs 29 min, p = .042) and a higher median number of passes to achieve recanalization (1 vs. 3, p = .002). There was no statistically significant difference in the long-term functional outcome between the groups. We suggest that dual-energy computed tomography could better distinguish between blood and pure contrast stagnation. Still, SAH was not associated with an unfavorable outcome in stroke patients undergoing thrombectomy.

Accuracy and Safety of Fluoroscopy-Assisted Transpedicular Screw Insertion in Thoracolumbar Spine Surgery: Evaluation of 122 Screws.

The objective of this study is to determine the accuracy and safety of trans-pedicular screws' insertion in the thoracolumbar spine using a fluoroscopy-assisted surgical technique. We retrospectively evaluated all patients who underwent a postoperative computed tomography scan to assess the location of the pedicular screws following thoracolumbar spinal surgery, at the Mohammed Vth Military Training Hospital-Rabat, from January 2020 to April 2022. We used Gertzbein's classification to grade pedicular cortex breaches. A screw penetration greater than 4 mm (grades D-E) was considered critical and one less than 4 mm was classified as noncritical (grades A-C). A total of 122 screws inserted in the T1 to L5 vertebrae were included from 25 patients. The average age was 46 years old. Pathologies included degenerative disorders (5 patients), tumors (8 patients), and trauma (12 patients). All screws were inserted using lateral and anteroposterior fluoroscopic guidance. A total of 11 transpedicular screws breaches were identified. The breaches incidence was significantly higher in thoracic pedicles (8 screws) than in lumbar pedicles (3 screws). Of these, three critical cases occurred in two patients and one of them required reintervention. The remaining eight exceedances were not critical and were closely monitored and followed up. Transpedicular screws fluoroscopy-assisted surgical fixation can be performed for the stabilization of the thoracolumbar spine with satisfactory safety and precision.

Routine postoperative computed tomography (CT) scans following acetabulum open reduction internal fixation (ORIF): A survey of orthopaedic traumatologists

ObjectiveThe purpose of this study was to assess the practices related to obtaining postoperative pelvic CT scans following acetabular ORIF and revision surgery rates. DesignA 20-question survey published on the Orthopaedic Trauma Association (OTA) website assessed each surgeon's preference and rationale for or against the routine use of postoperative CT scans for acetabular fractures. ParticipantsFellowship-trained orthopaedic traumatologists. Main outcome measurementsWe examined the percentage of surgeons ordering routine postoperative CT scans, surgeon demographics, and revision surgery rates based on these routine CT scan results. ResultsResponses were received from 57 surgeons. Practices varied regarding postoperative CT scans, with 16 surgeons (28%, Group A) routinely ordering them and 41 surgeons (72%, Group B) not ordering them on all patients. No significant difference in surgeon demographics were found between the groups. Majority of Group A report a revision surgery rate of <1% based on the results of the postoperative CT.Group A report routine postoperative scans were obtained to assess reduction, hardware placement, identify intra-articular fragments, and for educational purposes. Group B did not obtain routine postoperative CTs due to the following: unlikely to change postoperative treatment, adequate reduction and instrumentation placement assessed intraoperatively and by postoperative radiographs, and increased radiation exposure and cost to patients. Group B did report obtaining postop CT scans on select patients, with inadequate intraoperative imaging and postoperative neurological changes being the most common indications. ConclusionThe routine use of postoperative CTs following open reduction internal fixation of acetabular fractures is a controversial topic. While we recognize the role for postoperative CT scans in select patients, our study questions the clinical utility of these scans in all patients and in conclusion do not recommend this protocol.

Comparison of the accuracy of intraoperative lateral fluoroscopy versus postoperative computed tomography in spinal fusions.

This study compared the accuracy of intraoperative lateral fluoroscopic images versus postoperative computed tomography (CT) 3D studies in the treatment of thoracolumbar spinal fusions. In a tertiary care hospital (study duration 6 months), we compared the use of lateral fluoroscopic images with the postoperative CT scans in 64 patients with thoracic or lumbar fractures undergoing spinal fusions. Out of the 64 patients, 61% were lumbar followed by 39% thoracic fractures. In the lumbar spine, the accuracy of screw placement utilizing lateral fluoroscopy versus postoperative CT 3D was 97.4%, while in thoracic spine, accuracy was reduced to 84.4%. Of the 64 patients, just 4 (6.2%) patients demonstrated lateral pedicle cortex penetration, 1 (1.5%) patient had a medial pedicle cortex breach, while none exhibited anterior vertebral body cortex penetration. This study documented the efficacy of lateral fluoroscopy in intraoperative thoracic and lumbar spinal fixation as confirmed by postoperative CT 3D studies. These findings support the continued use of fluoroscopy rather than CT intraoperatively to lower the risk of radiation exposure to both patients and surgeons.

Clinical Significance of Lateral Pedicle Screw Malposition in Lumbar Spine Fusion.

Retrospective cohort study. Our objective was to determine whether lateral pedicle screw breach affects fusion rates and patient-reported outcomes in lumbar fusion surgery. Although lateral pedicle screw malposition is considered relatively benign, few studies have focused specifically on clinical outcomes or fusion rates associated with lateral screw malposition. Twelve-month postoperative computed tomography scans were reviewed for lateral breach, severity of breach, and fusion status. Patients with lateral breach were compared with patients with no breach. Outcome measures included Numerical Pain Rating Scale for back and leg pain, Oswestry Disability Index, and SF-36 physical function (SF-36 PF). Multivariable linear and logistic regression and were adjusted for age, procedure, level, and/or baseline pain score. Forty-five patients (31%) demonstrated 1 or more lateral breaches as compared with 99 patients without breach. After adjusting for baseline scores and fusion level, patients with 2 or more screw breaches experienced SF-36 PF score improvements that were 3.43 points less ( P =0.016) than patients with no lateral breach. After adjusting for baseline Numerical Pain Rating Scale, there was also a significant decrease in the odds of achieving minimally clinical important difference in back pain relief in these patients. There was no observed effect of lateral breach on the odds of successful fusion. The current study did not observe an association between laterally malpositioned pedicle screws and nonunion. However, results are consistent with a negative effect on SF-36 PF scores and self-reported back pain at 12 months.

Three-dimensional-printed patient-specific instrumentation is an accurate tool to reproduce femoral bone tunnels in multiple-ligament knee injuries

PurposeMultiple-ligament knee reconstruction techniques often involve the creation of several bone tunnels for various reconstruction grafts. A critical step in this procedure is to avoid short tunnels or convergences among them. Currently, no specific template guide to reproduce these angulations has been reported in the literature, and the success of the technique still depends on the experience of the surgeon. The aim of this study is to analyze the accuracy and reliability of 3D-printed patient-specific instrumentation (PSI) for lateral and medial anatomical knee reconstructions.MethodsTen cadaveric knees were scanned by computed tomography (CT). Using specific computer software, anatomical femoral attachments were identified: (1) on the lateral side the lateral collateral ligament (LCL) and the popliteal tendon (PT) and (2) on the medial side the medial collateral ligament (MCL) and the posterior oblique ligament (POL). Four bone tunnels were planned for each knee, and PSI with different directions were designed as templates to reproduce the planned tunnels during surgery. Twenty 3D-printed PSI were used: ten were tailored to the medial side for reconstructing MCL and POL tunnels, and the other ten were tailored to the lateral side for reconstructing LCL and PT tunnels. Postoperative CT scans were made for each cadaveric knee. The accuracy of the use of 3D-printed PSI was assessed by superimposing post-operative CT images onto pre-operative images and analyzing the deviation of tunnels performed based on the planning, specifically the entry point and the angular deviations.ResultsThe median entry point deviations for the tunnels were as follows: LCL tunnel, 1.88 mm (interquartile range (IQR) 2.2 mm); PT tunnel, 2.93 mm (IQR 1.17 mm); MCL tunnel, 1.93 mm (IQR 4.26 mm); and POL tunnel, 2.16 mm (IQR 2.39). The median angular deviations for the tunnels were as follows: LCL tunnel, 2.42° (IQR 6.49°); PT tunnel, 4.15° (IQR 6.68); MCL tunnel, 4.50° (IQR 6.34°); and POL tunnel, 4.69° (IQR 3.1°). No statistically significant differences were found in either the entry point or the angular deviation among the different bone tunnels.ConclusionThe use of 3D-printed PSI for lateral and medial anatomical knee reconstructions provides accurate and reproducible results and may be a promising tool for use in clinical practice.

Grid and Image Intensifier Improve Arthroscopic ACL Tunnel Position and Patient-Reported Outcomes

To evaluate the accuracy in the femoral and tibial tunnel placement after the use of fluoroscopy along with an indigenously designed grid method to assist in arthroscopic anterior cruciate ligament reconstruction as compared with the tunnel placement without using them and to validate the findings with computed tomography scan performed postoperatively along with assessing the functional outcome at a minimum of 3 years of follow-up. This was a prospective study conducted on patients who underwent primary anterior cruciate ligament reconstruction. Patients were included and segregated into a nonfluoroscopy (group B) and a fluoroscopy group (group A), and both had postoperative computed tomography scans so that femoral and tibial tunnel position could be evaluated. Scheduled follow-up occurred 3, 6, 12, 24, and 36 months' postoperatively. Patients were evaluated objectively with the Lachman test, measurement of range of motion, and functional outcome using patient-reported outcome measures, i.e., Tegner Lysholm Knee score, Knee injury and Osteoarthritis Outcome Score, and International Knee Documentation Committee subjective knee score. A total of 113 subjects were included. There were 53 in group A and 60 in group B. The average location of femoral tunnel showed significant differences between the 2 groups. However, the variability in femoral tunnel location was significantly lower in group A as compared with group B for proximal-distal planes only. The average location of the tibial tunnel as per the grid of Bernard etal. showed significant differences in both the planes. The variability in tibial tunnel was greater in the medial-lateral plane as compared with the anterior-posterior plane. There was a statistically significant difference in mean value of the 3 scores among the 2 groups. The variability of the scores was greater in group B as compared with group A. None of the patient was reported as a failure. The results of our study suggests that fluoroscopy-guided positioning using a grid technique increases the accuracy of anterior cruciate ligament tunnel positioning with decreased variability and is associated with better patient-reported outcomes 3 years after surgery compared with tunnel positioning using landmarks. Level II, prospective, comparative therapeutic trial.

Replacing cutting guides with an augmented reality-based navigation system: A feasibility study in the maxillofacial region.

The work presents outcomes of simulated maxillofacial skeleton osteotomies supported with cutting guides or one of two AR-based intraoperative navigation systems. The series of osteotomies supported with a cutting guide, simple AR (sAR) or navigated AR (nAR) module were carried out on 15 (five per each method) skull models according to the virtual surgical plan (VSP). Each method was used to support 40 osteotomies involving the upper jaw and 40 involving the orbital region (16 osteotomies on each model). Postoperative computed tomography scans were fused with the VSP to analyse angular deviations from the planned cutting trajectory (°) and the deviations of labelled control points (mm). Guides provided the highest accuracy, with a mean osteotomy angular deviation of 3.73±2.94° and a mean control point deviation of 1.30±0.73 mm. Mean angular deviations for the sAR- and nAR-assisted osteotomies were 5.93±5.12° and 6.75±5.33°, and mean control point deviations amounted to 1.86±0.88 mm and 1.97±0.70 mm.

Clinical and anatomical outcomes of isolated coracoclavicular fixation after acromioclavicular joint injury: is it stable enough or is additional horizontal fixation necessary?

Recently, an emphasis has been put on anatomical reduction of acromioclavicular (AC) joint both in vertical and hortizontal planes for management of AC joint injuries due to persisting horizontal instability. Therefore, an additional AC fixation in horizontal plane has been recommended. However, relation between horizontal AC joint instability and clinical outcomes is still controversial. This study aims to evaluate outcomes of isolated coraco-clavicular fixation using arthroscopic assisted single coraco-clavicular tunnel technique in grade III and V AC joint injuries and to investigate the correlation between anatomical and clinical outcomes. This study was conducted with 19 patients with grade III or V AC joint injury. Clinical outcomes included postoperative pain intensity and functional outcomes (Constant Score, American Shoulder and Elbow Surgeons, and Subjective Shoulder Value). Radiological evaluations were performed using radiographs and postoperative computed tomography scans. Degree of initial injury and postoperative stability both on axial and coronal planes were evaluated after radiological assessment. Correlations between anatomical and clinical outcomes were investigated using Pearson's correlation test. At the final follow-up assessment, the mean pain score was 1.8±1.8, mean American Shoulder and Elbow Surgeons score was 81.0±15.4, mean Subjective Shoulder Value was 81.3±19.6, and mean Constant Score was 86.3±14.8. The mean loosening ratio and AC distance were 43.5±30.6% and 4.3±12.4 mm, respectively. No correlation was observed between postoperative anatomical and clinical outcomes (P>.05). Additional AC fixation on horizontal plane is not a prerequisite for all injuries, there is no significant association between horizontal instability and clinical outcomes and indications of an additional AC fixation needs to be determined.

Free Flap Fat Volume is Not Associated With Recurrence or Wound Complications in Oral Cancer.

Adipose stem cells (ASCs) have been shown in many preclinical studies to be potent suppressors of the immune system. Prior studies suggest that ASCs may promote cancer progression and wound healing. However, clinical studies investigating the effects of native, or fat-grafted adipose tissue on cancer recurrence have generated mixed results. We investigated whether adipose content in reconstructive free flaps for oral squamous cell carcinoma (OSCC) is associated with disease recurrence and/or reduction in wound complications. Retrospective chart review. Academic medical center. We performed a review of 55 patients undergoing free flap reconstruction for OSCC over a 14-month period. Using texture analysis software, we measured the relative free flap fat volume (FFFV) in postoperative computed tomography scans and compared fat volume with patient survival, recurrence, and wound healing complications. We report no difference in mean FFFV between patients with or without recurrence: 13.47 cm3 in cancer-free survivors and 17.99 cm3 in cases that recurred (p = .56). Two-year recurrence-free survival in patients with high and low FFFV was 61.0% and 59.1%, respectively (p = .917). Although only 9 patients had wound healing complications, we found no trend in the incidence of wound healing complications between patients with high versus low FFFV. FFFV is not associated with recurrence or wound healing in patients undergoing free flap reconstruction for OSCC, suggesting adipose content should not be of concern to the reconstructive surgeon.

Does unenhanced computerized tomography as imaging standard post-retrograde intrarenal surgery paradoxically reduce stone-free rate and increase additional treatment for residual fragments? Outcomes from 5395 patients in the FLEXOR study by the TOWER group.

Assessment of residual fragments (RFs) is a key step after treatment of kidney stones. To evaluate differences in RFs estimation based on unenhanced computerized tomography (CT) versus X-rays/ultrasound after retrograde intrarenal surgery (RIRS) for kidney stones. A retrospective analysis of data from 20 centers of adult patients who had RIRS was done (January 2018-August 2021). Exclusion criteria: ureteric stones, anomalous kidneys, bilateral renal stones. Patients were divided into two groups (group 1: CT; group 2: plain X-rays or combination of X-rays/ultrasound within 3 months after RIRS). Clinically significant RFs (CSRFs) were considered RFs ⩾ 4 mm. One-to-one propensity score matching for age, gender, and stone characteristics was performed. Multivariable logistic regression analysis was performed to evaluate independent predictors of CSRFs. A total of 5395 patients were included (1748 in group 1; 3647 in group 2). After matching, 608 patients from each group with comparable baseline and stone characteristics were included. CSRFs were diagnosed in 1132 patients in the overall cohort (21.0%). Post-operative CT reported a significantly higher number of patients with RFs ⩾ 4 mm, before (35.7% versus 13.9%, p < 0.001) and after matching (43.1% versus 23.9%, p < 0.001). Only 21.8% of patients in the matched cohort had an ancillary procedure post-RIRS which was significantly higher in group 1 (74.8% versus 47.6%, p < 0.001). Age [OR 1.015 95% confidence interval (CI) 1.009-1.020, p < 0.001], stone size (OR 1.028 95% CI 1.017-1.040, p < 0.001), multiple stones (OR 1.171 95% CI 1.025-1.339, p = 0.021), lower pole stone (OR 1.853 95% CI 1.557-2.204, p < 0.001) and the use of post-operative CT scan (OR 5.9883 95% CI 5.094-7.037, p < 0.001) had significantly higher odds of having CSRFs. CT is the only reliable imaging to assess the burden of RFs following RIRS and urologist should consider at least one CT scan to determine the same and definitely plan reintervention only based on CT rather than ultrasound and X-ray combination.

Basilar invagination without atlantoaxial dislocation: treatment by correction of clivus canal angle with interfacet distraction and fixation

BackgroundThis study reports on the surgical technique used and clinical outcomes obtained during the treatment of basilar invagination (BI) without atlantoaxial dislocation (AAD) through the correction of the clivus canal angle (CCA) using interfacet distraction and fixation.MethodsNineteen cases with BI without AAD treated by the correction of the clivus canal angle were retrospectively analyzed. Pre- and postoperative computed tomography scans and three-dimensional reconstruction views were obtained to measure the size of the CCA, pB-C2 distance, and degree of BI. Chiari malformation and syringomyelia were evaluated by magnetic resonance imaging (MRI). The clinical outcomes for all patients were measured using the Japanese Orthopedic Association (JOA) scale. The CCA was corrected by using interfacet distraction and fixation techniques. The Wilcoxon test was used to compare pre- and postoperative measurements.ResultsAll the patients were followed up for 24.95 ± 5.22 months (range 12-36 months); no patient suffered intraoperative nerve or vascular injury. Clinical symptoms improved in 17 patients (89.5%). The mean JOA score increased from 12.32 ± 1.89 to 14.37 ± 1.30 (Z = -3.655, P < 0.001). The mean CCA improved from 129.34 ± 8.52° preoperatively to 139.75 ± 8.86° postoperatively (Z = -3.824, P < 0.001). The mean pB-C2 decreased from 7.47 ± 2.21 to 5.68 ± 3.13 (Z = -3.060, P = 0.002). Syringomyelia was significantly reduced in 10 out of 13 patients by the first follow-up year. All patients achieved bony fusion.ConclusionPosterior interfacet distraction and fixation to correct the CCA is a feasible and effective method for treating BI without AAD.

Accurate Deep Brain Stimulation Lead Placement Concurrent With Research Electrocorticography.

Using electrocorticography for research (R-ECoG) during deep brain stimulation (DBS) surgery has advanced our understanding of human cortical-basal ganglia neurophysiology and mechanisms of therapeutic circuit modulation. The safety of R-ECoG has been established, but potential effects of temporary ECoG strip placement on targeting accuracy have not been reported. To determine whether temporary subdural electrode strip placement during DBS implantation surgery affects lead implantation accuracy. Twenty-four consecutive patients enrolled in a prospective database who underwent awake DBS surgery were identified. Ten of 24 subjects participated in R-ECoG. Lead locations were determined after fusing postoperative computed tomography scans into the surgical planning software. The effect of brain shift was quantified using Lead-DBS and analyzed in a mixed-effects model controlling for time interval to postoperative computed tomography. Targeting accuracy was reported as radial and Euclidean distance errors and compared with Mann-Whitney tests. Neither radial error nor Euclidean distance error differed significantly between R-ECoG participants and nonparticipants. Pneumocephalus volume did not differ between the 2 groups, but brain shift was slightly greater with R-ECoG. Pneumocephalus volume correlated with brain shift, but neither of these measures significantly correlated with Euclidean distance error. There were no complications in either group. In addition to an excellent general safety profile as has been reported previously, these results suggest that performing R-ECoG during DBS implantation surgery does not affect the accuracy of lead placement.

Low-cost 3D Modeling Software for Generating Patient-specific Drill Guide Templates for Cervical Pedicle Screw Insertion: An In Vitro Study

Background. Instrumented posterior cervical spine surgery (IPCSS) can be conducted using screws inserted through the pedicles of the vertebra. A safe IPCSS method uses 3D-printing to produce templates that will serve as drill guides for screw placement.Objectives. This study describes the generation of 3D-printed drill guides using low-cost general purpose 3D modeling software and the comparison of screw insertion accuracy scores against the traditional landmark method and guides created using commercial grade software.Methods. Twenty-five (25) subaxial pedicles of five cadaveric spines were selected and scanned using computedtomography (CT). A digital reconstruction of the five cadaveric spines were created based on the CT DICOM data. A low-cost 3D modeling software, Rhinoceros 3D, was utilized for trajectory planning and generation of a patientspecific drill template using the digital reconstruction. The templates were then fabricated in ABS plastic using a fused deposition modeling (FDM) 3D printer. Insertion of cervical pedicle screws on the cadaveric spines was done by an orthopedic resident using the 3D printed guides. Postoperative CT scans were obtained, and placement accuracy of the screws were scored by two assessors utilizing a four-point rating system. Screws in correct placement were scored Grade 0 while misplaced screws with neurovascular damage were given a score of Grade 3.Results. Accuracy scores for the 3D-printed drill guides were 52% for assessor 1 and 44% for assessor 2. Forassessor 1, screw placement in C3, C6, and C7 received the highest scores. For assessor 2, the highest scores were achieved in C3 and C7. The hybrid method of Bundoc et al. achieved scores of 94% while 3D printed guides utilizing commercial software like Materialise Mimics, Geomagic Freeform, or UG Imageware achieved scores of 80-100%. The traditional landmark method had scores ranging from 12% to 94% depending on the skill of the surgeon.Conclusion. Commercial medical 3D image-based engineering software has high acquisition costs that might be beyond the reach of most institutions. A sub-$1000 general purpose 3D modeling software can be used to create drill templates. Several factors were identified in the design and fabrication of the template that can be addressed to increase accuracy. Trajectory planning can also be improved by automating the process. The researchers recommend further studies in these areas specially in the context of developing 3D printing as a support service for surgical operations in the Philippines.

Reduction in Radiation Exposure in Minimally Invasive Pedicle Screw Placement Using a Tubular Retractor: A Pilot Study

Percutaneous pedicle screw (PPS) placement is a minimally invasive spinal procedure that has been rapidly adopted over the last decade. However, PPS placement has elicited fear of increased radiation exposure from some surgeons, medical staff, and patients. This is because PPS placement is performed using a K-wire, and the operator must perform K-wire insertion into the pedicle under fluoroscopy. In order to prevent erroneous insertion, there are many occasions when direct insertion is required during radiation exposure, and the amount of radiation exposure to hands and fingers in particular increases. Although these problems are being addressed by navigation systems, these systems are still expensive and not widely available. Attempts have been made to address this situation using instrumentation commonly used in spinal surgery. First, it was considered to visualize anatomical bone markers using a tubular retractor and a microscope. In addition, the use of a self-drilling pin was adopted to locate the pedicle in a narrower field of view. Based on these considerations, a minimally invasive and highly accurate pedicle screw placement technique was developed while avoiding direct radiation exposure. This study evaluated radiation exposure and accuracy of pedicle screw placement using this new procedure in one-level, minimally invasive, transforaminal lumbar interbody fusion (MIS-TLIF). Data were collected retrospectively to review pedicle screw placement in single-level MIS TLIFs using a tubular retractor under a microscope. The total fluoroscopy time, radiation dose, and screw placement accuracy were reviewed. Extension of operating time was also evaluated. Twenty-four patients underwent single-level MIS TLIFs, with placement of 96 pedicle screws. There were 15 females and 9 males, with an average age of 64.8 years and a mean body mass index of 25.5 kg/m2. The mean operating time was 201.8 min. The mean fluoroscopic time was 26.8 s. The mean radiation dose of the area dose product was 0.0706 mGy∗m2. The mean radiation dose of air kerma was 6.0 mGy. The mean radiation dose of the entrance skin dose was 11.31 mGy. Postoperative computed tomography scans demonstrated 93 pedicle screws confined to the pedicle (97%) and three pedicle screw breaches (3.2%; two lateral, one medial). A patient with screw deviation of the medial pedicle wall developed right-foot numbness necessitating reoperation. There were no complications after reoperation. The average added time with this combined procedure was 39 min (range 16-69 min) per patient. This novel pedicle screw insertion technique compares favorably with other reports in terms of radiation exposure reduction and accuracy and is also useful from the viewpoint of avoiding direct radiation exposure to hands and fingers. It is economical because it uses existing spinal surgical instrumentation.

Pedicle Screw-Associated Violation of the Adjacent Unfused Facet Joint: Clinical Outcomes and Fusion Rates.

Retrospective review of a prospective randomized trial. To compare outcome scores and fusion rates in patients with and without pedicle screw-associated facet joint violation (FJV) after a single-level lumbar fusion. Clinical outcomes data and computed tomography (CT) imaging were reviewed for 157 patients participating in a multicenter prospective trial. Post-operative CT scans at 12-months follow-up were examined for fusion status and FJV. Patient-reported outcomes (PROs) included Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) for leg and low back pain. Chi-square test of independence was used to compare proportions between groups on categorical measures. Two-sample t-test was used to identify differences in mean patient outcome scores. Logistic regression models were performed to determine association between FJV and fusion rates. Of the 157 patients included, there were 18 (11.5%) with FJV (Group A) and 139 (88.5%) without FJV (Group B). Patients with FJV experienced less improvement in ODI (P = .004) and VAS back pain scores (P = .04) vs patients without FJV. There was no difference in mean VAS leg pain (P = .4997). The rate of fusion at 12-months for patients with FJV (27.8%) was lower compared to those without FJV (71.2%) (P = .0002). Patients with FJV were 76% less likely to have a successful fusion at 12-months. Pedicle screw-associated violation of the adjacent unfused facet joint during single-level lumbar fusion is associated with less improvement in back pain, back pain-associated disability, and a lower fusion rate at 1-year after surgery.