Screw Insertion Research Articles

Assessment of two entry points for S2 alar-iliac screw in a Japanese cohort using three-dimensional computed tomography scan

Lumbosacral fusion supplemented with sacropelvic fusion has recently been increasingly employed for correcting spinal deformity and is associated with lower incidence of pseudarthrosis and implant failure. To date, few studies have evaluated anatomical parameters and technical feasibility between different entry points for S2 alar-iliac screws. To compare anatomical parameters and technical feasibility of two entry points for the S2 alar-iliac screw (S2AIS) in a Japanese cohort using three-dimensional (3D) computed tomography (CT). Retrospective cohort study. Fifteen men and 15 women aged 50-79 years who underwent pelvic CT at our hospital in 2013. Screw length, lateral angulation, caudal angulation, angle range, distance from the entry point to the sacroiliac joint, distance from the S2AIS to the acetabular roof, distance from the S2AIS to the sciatic notch, and insertion difficulty. We used 30 pelvic CT images (15 men and 15 women). We selected two entry points from previous studies: one was 1 mm distal and 1 mm lateral to the S1 dorsal foramen (A group) and the other was the midpoint between the S1 and S2 dorsal foramen (B group). We resliced the plane in which the pelvis was sectioned obliquely from these entry points to the anterior inferior iliac spine in the sagittal plane. We placed the shortest and longest virtual S2AISs bilaterally in this plane using a 4-mm margin. We measured screw length, lateral angulation, caudal angulation, angle range, distance from the entry point to the sacroiliac joint, distance from the S2AIS to the acetabular roof, distance from the S2AIS to the sciatic notch, and insertion difficulty. These measurements were compared between Groups A and B. In group A, the angle in the sagittal plane was significantly smaller and the distance from the entry point to the sciatic notch was significantly longer than in group B. Group B demonstrated a significantly longer screw length, longer distance from the entry point to the sacroiliac joint, and longer distance from the entry point to the acetabular roof than group A. The rate of insertion difficulty of S2AIS was much higher in group A. Insertion of S2AIS from the midpoint between the S1 and S2 dorsal foramen compared with the entry at distal and lateral to S1 foramen enables insertion of longer screws with low insertion difficulty.

C2 pedicle screw insertion assisted by mobilization of the vertebral artery in cases with high-riding vertebral artery

Objective: To examine the feasibility, safety, and efficacy of mobilization of the vertebral artery for C2 pedicle screws in cases with high-riding vertebral artery (HRVA). Methods: The clinical data of 12 patients with basilar invagination and atlantoaxial dislocation underwent atlantoaxial reduction and fixation in the Department of Neurosurgery, the First Affiliated Hospital of University of Science and Technology of China between January 2020 and November 2021 were retrospectively analyzed. All patients had high-riding vertebral artery on at least one side that prohibited the insertion of C2 pedicle screws. There were 2 males and 10 females aged (48.0±12.8) years (range: 17 to 67 years). After correction of vertical dislocation during the operation, the C2 pedicle screw insertion and occipitocervical fixation and fusion were performed using the vertebral artery mobilization technique. Neurological function was assessed using the Japanese Orthopedic Association (JOA) scale. The preoperative and postoperative JOA score and the main radiological measurements, including the anterior atlantodental interval (ADI), the distance of the odontoid tip above the Chamberlain line, the clivus-canal angle, were collected and compared by paired t-test. Results: Mobilization of the high-riding vertebral artery was successfully completed, and C2 pedicle screws were then fulfilled after the vertebral artery was protected. There was no injury to the vertebral artery during the operation. Meanwhile, no severe surgical complications such as cerebral infarction or aggravated neurological dysfunction occurred during the perioperative period. Satisfactory C2 pedicle screw placement and reduction were achieved in all 12 patients. All patients achieved bone fusion 6 months after surgery. No looseness and shift in internal fixation or reduction loss was observed during the follow-up period. Compared to the preoperative, the postoperative ADI decreased from (6.1±1.9) mm to (2.0±1.2) mm (t=6.73, P<0.01), the distance of the odontoid tip above Chamberlain line decreased from (10.4±2.5) mm to (5.5±2.3) mm (t=7.12, P<0.01), the clivus-canal angle increased from (123.4±11.1) ° to (134.7±9.6) ° (t=2.50, P=0.032), the JOA score increased from 13.3±2.1 to 15.6±1.2 (t=6.99, P<0.01). Conclusion: The C2 pedicle screw insertion assisted by mobilization of the vertebral artery is safe and considerably effective, providing a choice for internal fixation in cases with high-riding vertebral arteries.

Treatment strategy for osteoporotic vertebral body fractures in the lumbar spine: a case report and literature review

This report describes the successful treatment of an osteoporotic compression fracture. A 74-year-old woman presented with severe low back pain and left sciatica that had lasted for 6 weeks. Four week of conservative treatment was not effective. The patient was bedridden and had difficulty walking. A past history of osteoporosis was noted. Multilevel compression fractures, central stenosis, and spondylolisthesis with overt instability were evident in the preoperative images. Decompression and fusion surgery, vertebroplasty, and preoperative and postoperative teriparatide administration were planned. A severe endplate injury in the lower vertebral body was detected during interbody fusion surgery using an anterior approach. Additional screw insertion with posterolateral fusion was planned to prevent aggravation of cage subsidence. Postoperative magnetic resonance imaging, computed tomography (CT), and X-ray images revealed sufficient decompression, no cement leakage, and no nerve injury. On the first postoperative day, the patient reported that the left sciatica symptoms had improved. Satisfactory ambulation was observed at the outpatient department after 6 months. Fusion in progress was evident on follow-up CT and X-ray images. This case offers insights into possible treatment strategies for osteoporotic compression fractures with severe endplate injury, overt instability, and radiculopathy of the lower lumbar spine.

Functional outcome of type 4 Pipkin classification of femoral head fracture operated by open reduction internal fixation by ganz safe surgical dislocation approach management: a case report

Fracture of the femoral head is a severe, relatively uncommon injury; typically, it may have associated with traumatic posterior dislocation of the hip joint with or without acetabulum fracture. The Pipkin classification is the most commonly used classification system. Controversies include the preferred surgical approach (anterior versus posterior) versus ganz safe surgical dislocation approach and whether to perform femoral head fragment excision or internal fixation. Presenting a case report of 28 years old young male with a motor vehicle road traffic accident and suffered a head of femur fracture on right hip joint with posterior wall of right acetabulum fracture with Judet-Letournel type posterior wall and type 4 Pipkin’s classification of femoral head fracture. This patient was undergone for emergency surgical intervention of open reduction, internal fixation through Ganz approach and insertion of Herbert screws for femoral head and interfragmentary screw for trochanteric osteotomy. The patient was followed up for 1 year and have a complete range of motion at hip joint with painless daily lifestyle. Type 4 Pipkin classification of femoral head fracture managed timely and with surgical intervention by ganz safe surgical dislocation approach provides visualization to femoral head and whole acetabulum with internal fixation of femur head by herbert screw which preserves normal anatomic contour of femoral head shows appropriate reduction of fracture fragments and it may also avoid hemiarthroplasty surgeries. Fracture of the femoral head has been associated with a relatively poor functional outcome and requires timely management and surgical intervention. Specially type 4 Pipkin classification of femoral head fracture treated by ganz safe surgical dislocation approach with internal fixation of femur head by herbert screw shows better outcome and avoid risk of AVN of femoral head. Complications associated with fracture of the femoral head and subsequent treatment include osteonecrosis, post-traumatic osteoarthritis, heterotopic ossification and implant failure.

Learning curves for robotic-assisted spine surgery: an analysis of the time taken for screw insertion, robot setting, registration, and fluoroscopy.

The purpose of this study was to clarify the learning curve for robotic-assisted spine surgery. We analyzed the workflow in robotic-assisted spine surgery and investigated how much experience is required to become proficient in robotic-assisted spine surgery. The data were obtained from consecutive 125 patients who underwent robotic-assisted screw placement soon after introducing a spine robotic system at a single center from April 2021 to January 2023. The 125 cases were divided into phases 1-5 of sequential groups of 25 cases each and compared for screw insertion time, robot setting time, registration time, and fluoroscopy time. There were no significant differences in age, body mass index, intraoperative blood loss, number of fused segments, operation time, or operation time per segment between the 5 phases. There were significant differences in screw insertion time, robot setting time, registration time, and fluoroscopy time between the 5 phases. The screw insertion time, robot setting time, registration time, and fluoroscopy time in phase 1 were significantly longer than those in phases 2, 3, 4, and 5. In an analysis of 125 cases after the introduction of the spine robotic system, the screw insertion time, robot setting time, registration time, and fluoroscopy time were significantly longer in the 25 cases in the period initially after introduction. The times were not significantly different in the subsequent 100 cases. Surgeons can be proficient in robotic-assisted spine surgery after their experience with 25 cases.

Parameters Governing the Fate of Fracture Fixation With Proximal Femoral Nailing (PFN) for Intertrochanteric Femur Fractures.

A high mortality rate is associated with hip fractures in the elderly. This is because their bones are osteoporotic with implants having less hold and there are more co-morbidities associated with the elderly.Osteosynthesis with the proximal femoral nail (PFN) features the advantages of high rotational stability of the head-neck fragment. However, the use of the nail is technically ambitious and is accompanied by some risks of error, which can lead to failure.This study aims to understand the technical difficulties related to PFN and methods to mitigate them and radiological indicators for successful outcomes of PFN. Our study aims to analyze the radiological parameters as indicators for the successful outcome of intertrochanteric fractures fixed using PFN and also the factors responsible for intraoperative conversion to dynamic hip screw (DHS). This is a prospective, observational study conducted from January 2020 to December 2020, on all the patients with intertrochanteric fractures who were planned to be treated by PFN and consented to be part of the study group at our institute. This study includes 99 cases of intertrochanteric fractures classified according to AO (Arbeitsgemeinschaft für Osteosynthesefragen)/Association of the Study of Internal Fixation (ASIF) and Evan's classification systems and followed postoperatively at regular intervals up to one year. Different methods of fracture reduction, intraoperative radiological parameters, and postoperative radiological parameters dictating the fate of PFN along with factors responsible for the intraoperative conversion to DHS were analyzed and discussed. Out of 99 patients planned for PFN, four were converted to DHS intraoperatively and 15 patients expired within the follow-up period of one year, leaving only 80 patients in the study group. Of them, seven patients (11.4%) had implant-related complications. According to Chang's reduction quality criteria (CRQC), two cases have CRQC 1 (poor reduction), 11 cases have CRQC 2 (acceptable reduction), 39 cases have CRQC 3 (acceptable reduction), and 28 cases have CRQC 4 (excellent reduction). Though PFN is technically challenging, with proper guidelines and technique,it gives excellent results. Most importantly, a nonvarus reduction, proper nail insertion and accurate placement of lag screws are the crucial factors for a successful outcome. Biomechanically stable reduction, by closed, percutaneous, or open means, is the key to treating unstable intertrochanteric fracture successfully.

Using a 3D Navigation Template to Increase the Accuracy of Thoracic Pedicle Screws in Patients with Scoliosis.

This study compares the accuracy and safety of pedicle screw placement using a 3D navigation template with the free-hand fluoroscopy technique in scoliotic patients. Fifteen scoliotic patients were recruited and divided into a template group (eight cases) and a free-hand group (seven cases). All patients received posterior corrective surgeries, and the pedicle screw was placed using a 3D navigation template or a free-hand technique. After surgery, the positions of the pedicle screws were evaluated using CT. A total of 264 pedicle screws were implanted in 15 patients. Both the two techniques were found to achieve satisfactory safety of screw insertion in scoliotic patients (89.9% vs. 90.5%). In the thoracic region, the 3D navigation template was able to achieve a much higher accuracy of screw than the free-hand technique (75.3% vs. 60.4%). In the two groups, the accuracy rates on the convex side were slightly higher than on the concave side, while no significance was seen. In terms of rotational vertebrae, no significant differences were seen in Grades I or II vertebrae between the two groups. In conclusion, the 3D navigation template technique significantly increased the accuracy of thoracic pedicle screw placement, which held great potential for extensively clinical application.

Incidence of and Risk Factors for Screw Loosening after Iliosacral Screw Fixation for Posterior Pelvic Ring Injury.

Screw loosening is a common complication of iliosacral screw fixation, with subsequent loss of stability and fracture re-displacement. This study aimed to investigate the incidence of and risk factors for screw loosening after iliosacral screw fixation for posterior pelvic ring injury. A total of 135 patients with posterior pelvic ring injuries who were treated with iliosacral screw fixation in our department between July 2015 and April 2021 were selected for this retrospective analysis. The possible risk factors for screw loosening were investigated using univariate and multivariate logistic regression analyses of patient demographics and trauma-related and iatrogenic variables, including age, sex, body mass index, Osteoporosis Self-Assessment Tool for Asians (OSTA) index, mechanism of injury, Young-Burgess classification, site of injury, type of injury, type of screw, mode of fixation, numbers of guidewire adjustments, accuracy of screw position, and quality of fracture reduction. The incidence of screw loosening was 15.6% (n = 21). The mean duration for screw loosening was 3.2 ± 1.5 months after operation. Univariate analysis results showed that the Young-Burgess classification, type of injury, site of injury, type of screw, mode of fixation, and OSTA index might be related to screw loosening (p < 0.05). According to the multivariate logistic regression, vertical shear injuries (Odds ratios [OR] 9.80, 95% Confidence intervals [CI] [1.96-73.28], p = 0.008), type of injury (OR 0.25, 95% CI [0.13-0.79], p = 0.027), common screws (OR 6.94, 95% CI [1.53-31.40], p = 0.012), screws insertion only at the level of the first sacral segment (S1) (OR 8.79, 95% CI [1.18-65.46], p = 0.034), injury site located in the medial sacral foramina (OR 6.28, 95% CI [1.16-34.06], p = 0.033), and lower OSTA index [OR 0.41, 95% CI [0.24-0.71], p = 0.001] were significantly related to screw loosening. Vertical shear injuries, sacral fractures, injury site located in the medial sacral foramina, and lower OSTA index are significantly associated with the postoperative occurrence of screw loosening. Transiliac-transsacral screw fixation and screws insertion both at the level of the S1 and second sacral segment can prevent screw loosening.

All-Arthroscopic Glenoid Bone Augmentation Using Iliac Crest Autograft Procedure for Recurrent Anterior Shoulder Instability: Button Fixation Is a Feasible and Satisfactory Alternative to Screw Fixation

To investigate the efficacy of all-arthroscopic glenoid bone augmentation surgery using the iliac crest autograft procedure. Furthermore, we sought to compare the clinical and radiographic outcomes of using screw versus button fixation, in patients with recurrent anterior shoulder instability. Between 2015 and 2019, 134 shoulders with persistent instability were surgically treated with an arthroscopically placed autologous iliac crest bone graft transfer procedure. Preoperative and postoperative clinical follow-up data were evaluated using the range of motion, and the Walch-Duplay, American Shoulder and Elbow Society, and Rowe scores. Radiologic assessment on 3-dimensional computed tomography scans was performed preoperatively, immediately after surgery, as well as postoperatively, at 3months, 6 months, 1 year, and at the final follow-up stage. Graft positions, healing, and resorption were evaluated from postoperative images. This study included 102 patients who underwent arthroscopic iliac crest bone grafting procedure with 2 screws fixation (n= 37; group 1) and 2 button fixation (n= 65; group 2). The mean follow-up period was 37 months. There were no significant differences between groups in terms of clinical scores, shoulder motion range, graft healing, or graft positions on computed tomography scans (P>.05). In group 1, 1 patient showed mechanical irritation and persistent pain around the screw insertion site, being treated through the arthroscopic removal of the screws. The average postoperative bony resorption percentages were 20.3% and 11.2% at 6 months, and 32.4% and 19.3% at 12 months, in group 1 and group 2, respectively. A statistically significant difference was detected between the two groups (P<.05). In the arthroscopic iliac crest bone grafting procedure for the treatment of chronic osseous anterior shoulder instability, excellent functional results were obtained after both button fixation and screw fixation techniques. In addition, less graft resorption and no hardware-related complications were detected with suture button fixation technique. Level III, retrospective comparative therapeutic trial.

Operative Effect Comparison of Flexible Drill Guiding vs. Traditional Drill Guiding Template for Lower Cervical Pedicle Screw Insertion: A Retrospective Analysis.

Accurately inserting pedicle screws is the key point of posterior pedicle screw fixation for lower cervical spine (C3-C7) instability. 3D printing technology can improve the accuracy of screw placement. This study compared the safety of 3D-printed flexible drill guiding template vs. traditional rigid drill guiding template for lower cervical pedicle screw insertion. This was a retrospective study. A total of 34 patients who underwent lower cervical pedicle screw fixation from March 2018 to May 2021 were enrolled in this study, and they were divided into the flexible drill flexible drill group and the traditional drill group. A total of 18 patients in the flexible drill flexible drill group underwent pedicle screw fixation assisted by 3D printed flexible drill guiding templates for the lower cervix, and 16 patients in the traditional drill group underwent pedicle screw fixation assisted by 3D printed regular drill guiding templates for the lower cervix. The length of the incision and intraoperative blood loss during surgery were recorded and compared for the two groups. The grade, deviation of the screw entry point, deviation of the screw medial angle and screw length were measured and compared after surgery for the two groups by independent-sample tests. There was a significant difference in the length of the incision and blood loss between the two groups (P < 0.05). There was a significant difference between the two groups for grade (P = 0.016). The deviation of the screw entry point was 0.65 ± 0.50 mm in the flexible drill group and 0.78 ± 0.83 mm in the traditional drill group. The deviation of the screw medial angle was 2.14 ± 1.78 in the flexible drill group and 4.23 ± 2.51 in the traditional drill group, with a significant difference between the two groups (P < 0.05). Compared with regular guiding techniques, lower cervical pedicle screw placement assisted by multistep navigation templates and flexible K-wires results in less trauma and better safety.

Safety of robotic-assisted screw placement for spine surgery: Experience from the initial 125 cases

BackgroundThe present study aimed to evaluate the safety of robot-assisted screw placement in 125 cases after introducing a spinal robotics system and to identify the situations where deviation was likely to occur. MethodsThe subjects were 125 consecutive patients who underwent robotic-assisted screw placement using a spinal robotics system (Mazor X Stealth Edition, Medtronic) from April 2021 to January 2023. The 1048 screws placed with robotic assistance were evaluated. We investigated intraoperative adverse events of the robotics system and complications occurring within 30 days after surgery. We evaluated screw accuracy and deviation and compared them for vertebral levels, screw insertion methods (open traditional pedicle screw [Open-PS], cortical bone trajectory screw [CBT], percutaneous pedicle screw [PPS], and S2 alar iliac screw [S2AIS]), diagnosis, and phases of surgical cases. ResultsThe deviation rate of robotic-assisted screw placement for spine surgery was 2.2%. Complications were reoperation due to implant-related neurological deficit in 0.8% and surgical site infection in 0.8%. There was significant difference in the deviation rate between vertebral levels. The deviation rate of the T1–T4 level was high at 10.0%. There was significant difference in the deviation rate between Open-PS, CBT, PPS, and S2AIS. The PPSs had a high deviation rate of 10.3%. The deviation rates were not significantly different between patients with and without deformity. The deviation rate did not change depending on the experience of surgical cases, and the deviation rate was favorable from the onset. ConclusionAlthough the robotic-assisted screw placement was safe, we should be extra vigilant when placing screws in the upper thoracic region (deviation rate 10.0%) and when using PPSs (deviation rate 10.3%).

Comparative study on the accuracy, safety and clinical effect of CT navigation and traditional open screw placement in the Treatment of Thoracic Fracture.

To explore the accuracy, safety and clinical effect of descending thoracic pedicle screw fixation assisted by computer CT three-dimensional navigation in the treatment of single segmental compression thoracic fracture. This study was a retrospective analysis. From June 2020 to June 2022, eighty patients with thoracic vertebral fractures admitted to Affiliated Hospital of Beihua University were were divided into observation group and control group according to different methods of screw placement, with 40 cases in each group. The navigation system was used to insert pedicle screws, and the control group used traditional open X-ray to insert pedicle screws by hand. Further comparison was carried out in terms of the operation time, intraoperative blood loss, perioperative complications, accuracy and safety rate of screw placement, and vertebral compression ratio between both the groups. The average intraoperative blood loss in the observation group was significantly less than the control group, the average screw insertion time was significantly shorter than the control group, the postoperative average vertebral body compression ratios was significantly better than the control group, the excellent rate of screw insertion was better than the control group, while the incidence of complications was lower than the control group, and the difference was statistically significant (all P<0.05). Intraoperative CT navigation for pedicle screw placement can reduce the time of screw placement and intraoperative blood loss, improve the excellent rate of screw placement and the compression ratio of the anterior edge of the injured vertebra, the complication rate was low.

Robotic-Assisted Minimally Invasive Spinopelvic Fixation for Traumatic Sacral Fractures: Case Series Investigating Early Safety and Efficacy

High-energy traumatic sacral fractures, particularly U-type or AOSpine classification type C fractures, may lead to significant functional deficits. Traditionally, spinopelvic fixation for unstable sacral fractures was performed with open reduction and fixation, but robotic-assisted minimally invasive surgical methods now present new, less invasive approaches. The objective here was to present a series of patients with traumatic sacral fractures treated with robotic-assisted minimally invasive spinopelvic fixation and discuss early experience, considerations, and technical challenges. Between June 2022 and January 2023, 7 consecutive patients met the inclusion criteria. Intraoperative fluoroscopic images were merged with intraoperative computed tomography images using a robotic system to plan the trajectories for placement of bilateral lumbar pedicle and iliac screws. Intraoperative computed tomography was performed after pedicle and pelvic screw insertion to confirm appropriate placement before insertion of rods percutaneously without the need for a side connector. The cohort consisted of 7 patients (4 female, 3 male) with ages ranging from 20 to 74. Intraoperatively, the mean blood loss was 85.7 ± 84.0 mL, and mean operative time was 178.4 ± 63.9 minutes. There were no complications in 6 patients; 1 patient experienced both a medially breached pelvic screw and a complicated rod pullout. All patients were safely discharged to their homes or an acute rehabilitation facility. Our early experience reveals that robotic-assisted minimally invasive spinopelvic fixation for traumatic sacral fractures is a safe and feasible treatment option with the potential to improve outcomes and reduce complications.

Biomechanical comparison of compact versus standard flute drill bits, and interlocking versus buttress thread self-tapping cortical bone screws in cadaveric equine third metacarpal condyle.

To compare (1) performance of compact versus standard flute drill bits, (2) screw insertion properties and (3) pullout variables between interlocking thread (ITS) and buttress thread (BTS) self-tapping screws in third metacarpi. In vitro experimental study. Paired third metacarpi from 11 Thoroughbreds aged 2-4 years. Screws were inserted into the lateral condylar fossae following bone preparation using the respective drill bit for each screw type. Screw pullout was achieved using a mechanical testing system. Density and porosity of bone surrounding screw holes was measured with microcomputed tomography following each pullout test. Drilling, screw insertion and pullout variables were compared between drill bit and screw types using repeated measures ANOVA. Linear regression analyses were used to characterize relationships between bone tissue properties and drill bit and screw outcomes. Maximum torque power spectral density (PSD) was lower for compact flute drill bits. Insertion torque was 50% higher for ITS. BTS had 33% greater preyield stiffness and 7% greater mean yield force. Bone tissue properties affected measured variables similarly for both screw and drill bit types. Lower torque PSD may increase durability of the compact flute drill bit. ITS had greater insertional torque, which may reflect greater bone engagement. BTS had greater resistance to axial pullout forces. Metacarpal bone provides a simple model for comparison of drill bit and screw designs. Use of ITS to repair equine fractures subject to predominantly tensile forces is not justified based on the results of this study.

The Child's Age and the Size of the Curvature Do Not Affect the Accuracy of Screw Placement with the Free-Hand Technique in Spinal Deformities in Children and Adolescents.

The current method of treatment of spinal deformities would be almost impossible without pedicle screws (PS) placement. There are only a few studies evaluating the safety of PS placement and possible complications in children during growth. The present study was carried out to evaluate the safety and accuracy of PS placement in children with spinal deformities at any age using postoperative computed tomography (CT) scans. 318 patients (34 males and 284 females) who underwent 6358 PS fixations for pediatric spinal deformities were enrolled in this multi-center study. The patients were divided into three age groups: less than 10 years old, 11-13 years old, and 14-18 years old. These patients underwent postoperative CT scans and were analyzed for pedicle screw malposition (anterior, superior, inferior, medial, and lateral breaches). The breach rate was 5.92% for all pedicles. There were 1.47% lateral and 3.12% medial breaches for all pedicles with tapping canals, and 2.66% lateral and 3.84% medial breaches for all pedicles without a tapping canal for the screw. Of the 6358 screws placed in the thoracic, lumbar, and sacral spine, 98% of the screws were accurately placed (grade 0, 1, and juxta pedicular). A total of 56 screws (0.88%) breached more than 4 mm (grade 3), and 17 (0.26%) screws were replaced. No new and permanent neurological, vascular, or visceral complications were encountered. The free-hand technique for pedicle screw placement in the acceptable and safety zone in pedicles and vertebral bodies was 98%. No complications associated with screw insertion in growth were noted. The free-hand technique for pedicle screw placement can be safely used in patients at any age. The screw accuracy does not depend on the child's age nor the size of the deformity curve. Segmental instrumentation with posterior fixation in children with spinal deformities can be performed with a very low complication rate. Navigation of the robot is only an auxiliary tool in the hands of the surgeons, and the result of the work ultimately depends on the surgeons.

Chronic sacroiliac joint dysfunction and CT-guided percutaneous fixation: a 6-year experience.

Reporting the clinical outcomes, patient satisfaction, and complications following an imaging-guided percutaneous screw fixation in the treatment of sacroiliac joint dysfunction and evaluating the safety and effectiveness of this method. We performed a retrospective study on a prospectively gathered cohort of patients with physiotherapy-resistant pain due to sacroiliac joint incompetence that underwent percutaneous screw fixation, between 2016 and 2022 in our center. A minimum of two screws were used in all patients to obtain fixation of the sacroiliac joint, using percutaneous screw insertion under CT guidance, coupled with a C-arm fluoroscopy unit. The mean visual analog scale significantly improved at 6months of follow-up (p < 0.05). One hundred percent of the patients reported significant improvement in pain scores at the final follow-up. None of our patients experienced intraoperative or postoperative complications. The use of percutaneous sacroiliac screws provides a safe and effective technique for the treatment of sacroiliac joint dysfunction in patients with chronic resistant pain.

Comparative Study on Accuracy of Intra-Operative Computed Tomography-Navigation Based Pedicle Screw Placement With Skin vs Bone Fixed Dynamic Reference Frame in Minimally Invasive Transforaminal Lumbar Interbody Fusion.

Retrospective comparative study. To compare the accuracy of intra-operative navigation-assisted percutaneous pedicle screw insertion between bone fixed and skin fixed dynamic reference frame (DRF) in Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Between October 2018 and September 2022, patients who underwent MIS-TLIF were included in this study with DRF fixed either on bone (group B) or skin (group S). Pedicle screws were inserted under the guidance of intra-operative Cone bean Computed tomography (cbCT) based navigation. Accuracy of pedicle screw placement was immediately checked by a final intra-operative cbCT Spin. Among 170 patients, group B included 91 patients and group S included 79 patients. Out of total 680 screws, 364 screws (group B) and 316 screws (group S) were placed. Patient's demographic data and distribution of screws showed no statistically significant difference. The accuracy showed no significant difference between both the groups (94.5% in group B and 94.3% in group S). Skin fixed DRF can serve as an alternate way for placement and avoids extra incision with similar accuracy in pedicle screw insertions with bone fixed DRF using intra-operative CT guided navigation in MIS TLIF.

Safety and accuracy of cannulated pedicle screw placement in scoliosis surgery: a comparison of robotic-navigation, O-arm-based navigation, and freehand techniques.

To compare the safety and accuracy of cannulated pedicle screw placement using a robotic-navigation technique, O-arm-based navigation technique, or freehand technique. This study analyzed 106 consecutive patients who underwent scoliosis surgery. Thirty-two patients underwent robotic-navigation-assisted pedicle screw insertion (Group 1), 34 patients underwent O-arm-based navigation-guided pedicle screw insertion (Group 2), and 40 patients underwent freehand pedicle screw insertion (Group 3). The primary outcome measure was the accuracy of screw placement. Secondary outcome parameters included operation time, blood loss, radiation exposure, and postoperative stay. A total of 2035 cannulated pedicle screws were implanted in 106 patients. The accuracy rate of the first pedicle screw placement during operation was significantly greater in Group 1 (94.7%) than in Group 2 (89.2%; P < 0.001). The accuracy rate of pedicle screw placement postoperatively decreased in the order of Group 1 (96.7%) > Group 2 (93.0%) > Group 3 (80.4%; P < 0.01). There were no significant differences in blood loss or postoperative stay among the three groups (P > 0.05). The operation times of Group 1 and Group 2 were significantly longer than that of Group 3 (P < 0.05). The robotic-navigation and O-arm-based navigation techniques effectively increased the accuracy and safety of pedicle screw insertion alternative to the freehand technique in scoliosis surgery. Compared with the O-arm-based navigation technique, the robotic-navigation technique increases the mean operation time, but also increases the accuracy of pedicle screw placement. A three-dimensional scan after insertion of the K-wire may increase the accuracy of pedicle screw placement in the O-arm-based navigation technique.

Let's think beyond the pedicle: A biomechanical study of a new conceptual extra pedicular screw and hook construct

BackgroundTranspedicular screws have proven the test of time, yet they are not devoid of complications. Many newer techniques such as 2 D and 3D fluoroscopy,O arm Navigation assisted surgery, robotic assisted surgery have come into existence to the increase precision in pedicle screw insertion. But, complications do occur in their presence. We propose an Extra pedicular screw and hook system (EPSH) system with similar biomechanical property, better safety profile and short learning curve compared to traditional pedicle screw. PurposeTo Compare the pull out strength of Traditional Pedicle screw Vs Extra pedicular screw and hook system(EPSH). MethodsBiomechanical testing was conducted according ASTM F543 guidelines to compare the pull-out strength of EPSH based construct and traditional pedicle screw construct. Six saw bone samples in each group considered. Screw of 5.5 mm diameter and length of 35 mm was used in both the groups. Pull out strength assessed by giving 5 mm/min axial load. The axial load Vs displacement of the screw were recorded and plotted. The maximum load required for screw failure is noted in both the group. Statistical analysis was done. ResultsThe mean peak load of pedicle screw group was found to be 1670.9 ± 393.2 N with mean displacement at peak load was found to be 13.44 ± 1.7 mm and in EPSH group it was 1416.4 ± 341.4 N and 15.78 ± 3.9 mm respectively. A paired t-test showed no statistical difference(p < 0.05) between 2 groups. ConclusionEPSH has shown to have almost similar biomechanical property as that pedicle screw construct. With Addition of the hook, it provides an extra rotational stability as well. Being an extra-pedicular screw it has high safety profile and needs less expertise for insertion.

최소침습 골절정복 수술에서 나사못 삽입 경로를 유도하는 시스템

In this paper, we propose a system to detect the location and direction of locking screw insertion using only a fluoroscopic image and guide screw insertion path, with a device that combines a SCARA robot arm and a conical remote center-of-motion (RCM) mechanism. In the proposed system, the target location and direction for screw insertion were derived from the fluoroscopic image of an intramedullary nail. The insertion guidance device comprise the SCARA robot arm and the RCM mechanism. The insertion guidance device calculated the current indicated path through forward kinematics analysis, and the target path and the current path were transmitted to the orthopedic surgeon through the control program. Moreover, the insertion guidance device set the insertion position and direction independently. The orthopedic surgeon first adjusted the SCARA robot arm to match the insertion position value to the target value and then sequentially adjusted the RCM mechanism so that the insertion direction matched the target value. After determining the insertion position and direction, the orthopedic surgeon inserted the surgical instrument through the path guided by the insertion guidance device and fastened the screw to the bone fragments and the intramedullary nail. When the proposed screw insertion guidance system was applied to fracture surgery, the locking screw was fastened with a minimum number fluoroscopic image, thus reducing surgery time and radiation exposure. The validity of the proposed method was confirmed through simulations and experiments using a fracture model.