Objective To biomechanically compare the maximum pull-out strengths among two pedicle screws and three salvage techniques using poly methylmethacrylate (PMMA) augmentation in osteoporotic sacrum, and to determine which PMMA augmentation technique could serve as the salvage fixation for loosening sacral pedicle screws. Methods Eleven sacra were harvested from fresh adult donated cadavers, aged from 66 to 83 years (average 74.4 years) and included 5 men and 6 women. Radiography was used to exclude sacra that showed tumor or inflammatory or any other anatomic abnormal ities. Following the measurement of bone mineral density, five sacral screw fixations were sequentially establ ished on the same sacrum as follows: unicortical pedicle screw (group A), bicortical pedicle screw (group B), unicortical pedicle screw with the traditional PMMA augmentation (group C), ala screw with the traditional PMMA augmentation (group D), and ala screw with a kyphoplasty-assisted PMMA augmentation technique (group E). According to the sequence above, the axial pull-out test of each screw was conducted on a MTS-858 material testing machine. The maximum pull-out forces were measured and compared. The morphologies of PMMA augmented screws after being pulled-out were also inspected. Results The average bone mineral density of 11 osteoporotic specimens was (0.71 ± 0.08) g/cm2 . By observation of the pull-out screws, groups C, D, E showed perfect bonding with PMMA, and group E bonded more PMMA than groups C and D. The maximum pull-out forces of groups A, B, C, D, and E were (508 ± 128), (685 ± 126), (846 ± 230), (543 ± 121), and (702 ± 144) N, respectively. The maximum pull-out strength was significantly higher in groups B, C, and E than in groups A and D (P lt; 0.05), and in group C than in groups B and E (P lt; 0.05). There was no significant difference in pull-out strength between groups A and D, and between groups B and E (P gt; 0.05). Conclusion For sacral screw fixation of osteoporotic patients with bone mineral density more than 0.7 g/cm2, bicortical pedicle screw could acquire significantly higher fixation strength than the unicortical. Once the loosening of pedicle screw occurs, the traditional PMMA augmentation or ala screw with kyphoplasty-assisted PMMA augmentation may serve as a suitable salvage technique.
Objective To compare the effectiveness of spinal robot-assisted pedicle screw placement through different surgical approaches and to guide the clinical selection of appropriate robot-assisted surgical approaches. MethodsThe clinical data of 14 patients with thoracolumbar vertebral diseases who met the selection criteria between January 2023 and August 2023 were retrospectively analyzed, and all of them underwent pedicle screw placement under assistant of the Mazor X spinal surgery robot through different surgical approaches. The patients were divided into posterior median approach (PMA) group (n=6) and intermuscular approach (IMA) group (n=8) according to the surgical approaches, and there was no significant difference in age, gender, body mass index, disease type, and fixed segment between the two groups (P>0.05). The operation time, intraoperative blood loss, screw-related complications, and reoperation rate were recorded and compared between the two groups; the inclination angle of the screw, the distance between the screw and the midline, and the caudal inclination angle of the screw were measured based on X-ray films at immediate after operation. Results There was no significant difference in operation time and intraoperative blood loss between the two groups (P>0.05). There was no screw-related complication such as nerve injury in both groups, and no patients underwent secondary surgery. At immediate after operation, the inclination angle of the screw, the distance between the screw and the midline, and the caudal inclination angle of the screw in the IMA group were significantly greater than those in the PMA group (P<0.05). ConclusionThere are differences in the position and inclination angle of screws placed with robot-assisted surgery through different surgical approaches, which may be due to the obstruction of the screw path by soft tissues such as skin and muscles. When using spinal robot-assisted surgery, selecting the appropriate surgical approach for different diseases can make the treatment more reasonable and effective.
ObjectiveTo explore the efficacy of percutaneous pedicle screw internal fixation and minimally invasive lateral small incisions lesion debridement and bone graft fusion via dilated channels in the treatment of lumbar tuberculosis.MethodsThe clinical data of 22 cases of lumbar tuberculosis treated with percutaneous pedicle screw internal fixation combined with dilated channels with minimally invasive lateral small incision lesion debridement and bone graft fusion between January 2016 and June 2018 were retrospectively analyzed. There were 12 males and 10 females, with an average age of 47.5 years (range, 22-75 years). The affected segments were L2, 3 in 5 cases, L3, 4 in 8 cases, and L4, 5 in 9 cases, with an average disease duration of 8.6 months (range, 4-14 months). Preoperative neurological function was classified according to the American Spinal Injury Association (ASIA), with 3 cases of grade C, 9 cases of grade D, and 10 cases of grade E. The operation time, intraoperative blood loss, and postoperative complications were recorded. At preoperation, 3 months after operation, and last follow-up, the C reactive protein (CRP) and erythrocyte sedimen- tation rate (ESR) were tested to evaluate tuberculosis control; the pain visual analogue scale (VAS) score was used to evaluate the recovery of pain, and the Oswestry disability index (ODI) was used to evaluate the function recovery of the patient’s lower back; the kyphosis Cobb angle was measured, and the loss of Cobb angle (the difference between the Cobb angle at last follow-up and 3 months after operation) was calculated. At last follow-up, the ASIA classification was used to evaluate the recovery of neurological function, and the effectiveness was evaluated according to the modified MacNab standard.ResultsThe operation time was 110-148 minutes (mean, 132.8 minutes) and the intraoperative blood loss was 70-110 mL (mean, 89.9 mL). Two patients experienced fat liquefaction of the incision and delayed healing; the incisions of the remaining patients healed by first intention. All patients were followed up 18-24 months, with an average of 21.3 months. All bone grafts achieved osseous fusion, the pedicle screws were fixed in reliable positions, without loosening, displacement, or broken rods. There was no recurrence of tuberculosis. The ESR, CRP, VAS scores, ODI scores, and kyphosis Cobb angle of the affected segment at 3 months after operation and last follow-up were significantly improved (P<0.05); there were no significant differences between at last follow-up and 3 months after operation (P>0.05), and the loss of Cobb angle was (0.6±0.5)°. The patient’s neurological function recovered significantly. At last follow-up, the ASIA grades were classified into 1 case with grade C, 1 case with grade D, and 20 cases with grade E, which were significantly improved when compared with preoperative grading (Z=?3.066, P=0.002). According to the modified MacNab standard, 16 cases were excellent, 3 cases were good, 2 cases were fair, and 1 case was poor. The excellent and good rate was 86.4%.ConclusionPercutaneous pedicle screw internal fixation combined with dilated channels with minimally invasive lateral small incisions lesion debridement and bone graft fusion has the advantages of less bleeding, less trauma, and faster recovery, which is safe and effective in the treatment of lumbar tuberculosis.
ObjectiveTo evaluate the clinical efficacy of domestic minimally-invasive percutaneous screw system for thoracolumbar fractures without neurological damage. MethodsSixty patients suffering from unstable thoracolumbar fractures without obvious neurologic deficits treated from January 2011 to April 2012 were studied retrospectively. The patients were divided into two groups:group A (domestic minimally-invasive percutaneous screw system) and group B (imported minimally-invasive percutaneous screw system). Perioperative parameter, pre-and post-operative imaging indexes, visual analog scale (VAS) and modified MacNab evaluation standard were studied for comparison. ResultsAll the patients were followed up from 6 to 18 months with an average of (12.2±3.0) months. The Cobb's angle and anterior height of the fracture vertebral body changed significantly in each group (P<0.05). There was no significant difference in incision size, surgical time, postoperative improvement of Cobb's angle, anterior height of the fracture vertebral body and accuracy of pedicle screw placement between the two groups (P>0.05). ConclusionDomestic minimally-invasive percutaneous screw system is reliable with minimal invasion, which is comparable to imported minimally-invasive percutaneous screw system.
Objective To explore the clinical effect of PSIS-A robot-assisted percutaneous screw in the treatment of thoracolumbar fracture. Methods Patients with thoracolumbar fracture who were hospitalized in Mianyang Orthopedic Hospital between August 2022 and January 2024 and required percutaneous pedicle screw f ixation were selected. Patients were divided into robot group and free hand group by random number table. Operative time, intraoperative bleeding, intraoperative radiation dose and time, implant accuracy rate, small joint invasion rate, Visual Analogue Scale score for pain and other indexes were compared between the two groups. Results A total of 60 patients were included. Among them, there were 28 cases in the robot group and 32 cases in the free hand group. On the third day after surgery, the Visual Analogue Scale score of the robot group was better than that of the free hand group (P=0.003). Except for intraoperative bleeding and radiation frequency (P>0.05), the surgical time, average nail implantation time, and intraoperative radiation dose in the robot group were all lower than those in the free hand group (P<0.05). The accuracy and excellence rate of nail planting in the robot group were higher than those in the free hand group (94.6% vs. 84.9%; χ2=7.806, P=0.005). There was no statistically significant difference in the acceptable accuracy rate (96.4% vs. 91.1%; χ2=3.240, P=0.072) and the incidence of screw facet joint invasion (7.2% vs.14.1%; χ2=3.608, P=0.058) between the two groups. Conclusion The application of PSIS-A type robot assisted percutaneous minimally invasive pedicle screw fixation in the treatment of thoracolumbar fr actures is promising.
Objective To analyze the therapeutic effect of the posterior pedicle screw system combined with interbody fusion cage on lumbarspondylolisthesis. Methods From February 2003 to March 2006, 37 lumbar spondylolisthesis patients were treated with this operation, including21 males and 16 females and aging 3969 years.The affected lumbars were L3(3cases)，L4(23 cases), and L5(11 cases). According to the Meyerdingevaluating system, 12 cases were lassified as degree Ⅰ, 20 cases as degree Ⅱ,and 5 cases as degree Ⅲ. Taillard index, Boxall index, slipping angle, lumbar lordosis angle and intervertebral height index were measured before operation, and 2 weeks and 3 months after operation. Results All patients were followed up 336 months. There were statistically significant differences in Taillard index, Boxall index, slipping angle, lumbar lordosis angle and intervertebral height index between before operation and 2 weeks after operation (P＜0.05),and no statistically significant differences between 2 weeks and 3 months afteroperation(P＞0.05). According to Dewei Zhou’s creterior for scoring, the results were excellent in 27 cases， good in 8 cases，and fair in 2 cases. Theexcellent and good rate was 94.6%. All of the embedded osseous were fused. Thefusing time was from 3 to 8 months (mean 3-9 months). There were no breakageof screw and rod. The position and configuration of the whole cages were good. Conclusion Applying the posterior pedicle screw system combined with interbody fusion cage may achieve synergism in the treatment of lumbar vertebral spondylolisthesis. Above procedure is served as solid internal fixationand offers a satisfactory reduction, and can improve the fusion rate of the spine. So it is an ideal procedure and worthily recommended method for treatment oflumbar vertebral spondylolisthesis.
Objective To explore the clinical application value of the spinal robot-assisted surgical system in mild to moderate lumbar spondylolisthesis and evaluate the accuracy of its implantation. Methods The clinical data of 56 patients with Meyerding grade Ⅰ or Ⅱ lumbar spondylolisthesis who underwent minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) between January 2017 and December 2017 were retrospectively analysed. Among them, 28 cases were preoperatively planned with robotic arm and percutaneous pedicle screw placement according to preoperative planning (group A); the other 28 cases underwent fluoroscopy-guided percutaneous pedicle screw placement (group B). There was no significant difference in gender, age, body mass index, slippage type, Meyerding grade, and surgical segmental distribution between the two groups (P>0.05). The screw insertion angle was measured by CT, the accuracy of screw implantation was evaluated by Neo’s criteria, and the invasion of superior articular process was evaluated by Babu’s method. Results One hundred and twelve screws were implanted in the two groups respectively, 5 screws (4.5%) in group A and 26 screws (23.2%) in group B penetrated the lateral wall of pedicle, and the difference was significant (χ2=9.157, P=0.002); the accuracy of nail implantation was assessed according to Neo’s criteria, the results were 107 screws of degree 0, 3 of degree 1, 2 of degree 2 in group A, and 86 screws of degree 0, 16 of degree 1, 6 of degree 2, 4 of degree 3 in group B, showing significant difference between the two groups (Z=4.915, P=0.031). In group B, 20 (17.9%) screws penetrated the superior articular process, while in group A, 80 screws were removed from the decompression side, and only 3 (3.8%) screws penetrated the superior articular process. According to Babu’s method, the degree of screw penetration into the facet joint was assessed. The results were 77 screws of grade 0, 2 of grade 1, 1 of grade 2 in group A, and 92 screws of grade 0, 13 of grade 1, 4 of grade 2, 3 of grade 3 in group B, showing significant difference between the two groups (Z=7.814, P=0.029). The screw insertion angles of groups A and B were (23.5±6.6)° and (18.1±7.5)° respectively, showing significant difference (t=3.100, P=0.003). Conclusion Compared to fluoroscopy-guided percutaneous pedicle screw placement, robot-assisted percutaneous pedicle screw placement has the advantages such as greater accuracy, lower incidence of screw penetration of the pedicle wall and invasion of the facet joints, and has a better screw insertion angle. Combined with MIS-TLIF, robot-assisted percutaneous pedicle screw placement is an effective minimally invasive treatment for lumbar spondylolisthesis.
Objective To investigate the effectiveness of injured vertebra fixation with inclined-long pedicle screws combined with interbody fusion for thoracolumbar fracture dislocation with disc injury. Methods Between January 2017 and June 2022, 28 patients with thoracolumbar fracture dislocation with disc injury were underwent posterior depression, the injured vertebra fixation with inclined-long pedicle screws, and interbody fusion. There were 22 males and 6 females, with a mean age of 41.4 years (range, 22-58 years). The causes of injury included falling from height in 18 cases, traffic accident in 5 cases, and bruise in 5 cases. Fracture segment included 1 case of T11, 7 cases of T12, 9 cases of L1, and 11 cases of L2. According to the American Spinal Injury Association (ASIA) scale, the spinal injuries were graded as grade A in 4 cases, grade B in 2 cases, grade C in 11 cases, and grade D in 11 cases. Preoperative spinal canal encroachment ratio was 17.7%-75.3% (mean, 44.0%); the thoracolumbar injury classification and severity score (TLICS) ranged from 9 to 10 (mean, 9.9). Seventeen patients were associated with other injuries. The time from injury to operation ranged from 1 to 4 days (mean, 2.3 days). The perioperative indicators (operation time, intraoperative blood loss, and the occurrence of complications), clinical evaluation indicators [visual analogue scale (VAS) score and Oswestry Disability Index (ODI)], radiologic evaluation indicators [anterior vertebral height ratio (AVHR), kyphosis Cobb angle (KCA), intervertebral space height (ISH), vertebral wedge angle (VWA), displacement angle (DA), and percent fracture dislocation displacement (PFDD)], neurological function, and interbody fusion were recorded. Results The operation time was 110-159 minutes (mean, 130.2 minutes). The intraoperative blood loss was 200-510 mL (mean, 354.3 mL). All incisions healed by first intention, and no surgical complications such as wound infection or hematoma occurred. All patients were followed up 12-15 months (mean, 12.7 months). The chest and lumbar pain significantly relieved, VAS scores and ODI after operation were significantly lower than those before operation, and further decreased with the extension of postoperative time, with significant differences (P<0.05). At last follow-up, the ASIA classification of neurological function of the patients was grade A in 3 cases, grade B in 1 case, grade C in 1 case, grade D in 10 cases, and grade E in 13 cases, which was significantly different from preoperative one (Z=?4.772, P<0.001). Imaging review showed that AVHR, KCA, ISH, VWA, DA, and PFDD significantly improved at 1 week, 3 months and last follow-up (P<0.05). There was no significant difference between different time points after operation (P>0.05). At last follow-up, according to the modified Brantigan score, all patients achieved good intervertebral bone fusion, including 22 complete fusion and 6 good intervertebral fusion with a few clear lines. No complications such as internal fixation failure or kyphosis occurred during follow-up.Conclusion The injured vertebra fixation with inclined-long pedicle screws combined with interbody fusion is an effective treatment for thoracolumbar fracture dislocation with disc injury, which can correct the fracture dislocation, release the nerve compression, restore the injured vertebral height, and reconstruct spinal stabilization.
Objective To explore the feasibility and accuracy of ultrasound volume navigation (UVN) combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation through a prospective randomized controlled study. Methods Patients with thoracic and lumbar vertebral fractures scheduled for percutaneous pedicle screw fixation between January 2022 and January 2023 were enrolled. Among them, 60 patients met the selection criteria and were included in the study. There were 28 males and 32 females, with an average age of 49.5 years (range, 29-60 years). The cause of injury included 20 cases of traffic accidents, 21 cases of falls, 17 cases of slips, and 2 cases of heavy object impact. The interval from injury to hospital admission ranged from 1 to 5 days (mean, 1.57 days). The fracture located at T12 in 15 cases, L1 in 20 cases, L2 in 19 cases, and L3 in 6 cases. The study used each patient as their own control, randomly guiding pedicle screw implantation using UVN combined with X-ray fluoroscopy on one side of the vertebral body and the adjacent segment (trial group), while the other side was implanted under X-ray fluoroscopy (control group). A total of 4 screws and 2 rods were implanted in each patient. The implantation time and fluoroscopy frequency during implantation of each screw, angle deviation and distance deviation between actual and preoperative planned trajectory by imaging examination, and the occurrence of zygapophysial joint invasion were recorded. Results In terms of screw implantation time, fluoroscopy frequency, angle deviation, distance deviation, and incidence of zygapophysial joint invasion, the trial group showed superior results compared to the control group, and the differences were significant (P<0.05). Conclusion UVN combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation can yreduce screw implantation time, adjust dynamically, reduce operational difficulty, and reduce radiation damage.
ObjectiveTo investigate the accuracy of progressive three-dimensional navigation template system (abbreviated as progressive template) to assist atlas-axial pedicle screw placement. MethodsThe clinical data of 33 patients with atlas-axial posterior internal fixation surgery between May 2015 and May 2017 were retrospectively analyzed. According to the different methods of auxiliary screw placement, the patients were divided into trial group (19 cases, screw placement assisted by progressive template) and control group (14 cases, screw placement assisted by single navigation template system, abbreviated as initial navigation template). There was no significant difference in gender, age, cause of injury, damage segments, damage types, and preoperative Frankel classification between the two groups (P>0.05). The operation time and intraoperative blood loss of the two groups were compared. The safety of screw placement was evaluated on postoperative CT by using the method from Kawaguchi et al, the deviation of screw insertion point were calculated, the angular deviation of the nailing on coordinate systems XOZ, XOY, YOZ were calculated according to Peng’s method. ResultsAll patients completed the operation successfully; the operation time and intraoperative blood loss in the trial group were significantly less than those in the control group (t=–2.360, P=0.022; t=–3.006, P=0.004). All patients were followed up 12–40 months (mean, 25.3 months). There was no significant vascular injury or nerve injury aggravation. Postoperative immediate X-ray film and CT showed the dislocation was corrected. Postoperative immediate CT showed that all 76 screws were of grade 0 in the trial group, and the safety of screw placement was 100%; 51 screws were of grade 0, 3 of gradeⅠ, and 2 of gradeⅡ in the control group, and the safety of screw placement was 91.1%; there was significant difference in safety of screw placement between the two groups (χ2=7.050, P=0.030). The screw insertion point deviation and angular deviation of the nailing on XOY and YOZ planes in the trial group were significantly less than those in the control group (P<0.05). There was no significant difference in angular deviation of the nailing on XOZ between the two groups (t=1.060, P=0.290). ConclusionCompared with the initial navigation template, the progressive navigation template assisting atlas-axial pedicle screw placement to treat atlas-axial fracture with dislocation, can reduce operation time and intraoperative blood loss, improve the safety of screw placement, and match the preoperative design more accurately.