Objective
To compare the effectiveness of cortical bone trajectory screw (CBTS) and conventional pedicle screw for posterior lumbar interbody fusion (PLIF) in the treatment of single segment lumbar degenerative disease.
Methods
Between May 2013 and May 2016, a total of 97 patients with single segment lumbar degenerative disease were treated with PLIF. Fifty-one patients were fixed with CBTS in PLIF (trajectory screw group) and 46 with pedicle screw (pedicle screw group). There was no significant difference in age, gender, body mass index, preoperative diagnosis, lesion segment, and preoperative visual analogue scale (VAS) score, Oswestry dysfunction index (ODI) between 2 groups (P>0.05). The operation time, intraoperative blood loss, postoperative drainage, bed rest time, length of hospital stay, serum creatine kinase (CK) concentration, total amount of diclofenac sodium, perioperative complications, ODI, VAS score, and interbody fusion rate were recorded and compared between 2 groups.
Results
All patients were followed up 12 months. The patients in trajectory screw group had a significantly less operation time, intraoperative blood loss, postoperative drainage, and serum CK concentration when compared with the patients in pedicle screw group (P<0.05). Thirty-five patients (68.6%) in trajectory screw group and 46 patients (100%) in pedicle screw group were given diclofenac sodium within 48 hours after operation, showing significant difference between 2 groups (χ2=89.334, P=0.000). There was no significant difference in the incidence of perioperative complications between trajectory screw group and pedicle screw group (3.9% vs. 8.7%, P=0.418). There was no significant difference in the VAS score, ODI, and interbody fusion rate at 12 months after operation between 2 groups (P>0.05).
Conclusion
For the single segment degenerative lumbar disease, the use of CBTS or conventional pedicle screw for PLIF can obtain satisfactory clinical function and interbody fusion rate. But the former has the advantages of less blood loss, less intraoperative muscle damage, less perioperative pain, shorter length of hospital stay and bed rest time.
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 evaluate the biomechanical stability of a newly-designed Y type pedicle screw (YPS) in osteoporotic synthetic bone.
Methods
The osteoporotic synthetic bone were randomly divided into 3 groups (n=20). A pilot hole, 3.0 mm in diameter and 30.0 mm in deep, was prepared in these bones with the same method. The YPS, expansive pedicle screw (EPS), and bone cement-injectable cannulated pedicle screw (CICPS) were inserted into these synthetic bone through the pilot hole prepared. X-ray film examination was performed after 12 hours; the biomechanical stability of YPS, EPS, and CICPS groups was tested by the universal testing machine (E10000). The test items included the maximum axial pullout force, the maximum running torque, and the maximum periodical anti-bending.
Results
X-ray examination showed that in YPS group, the main screw and the core pin were wrapped around the polyurethane material, the core pin was formed from the lower 1/3 of the main screw and formed an angle of 15° with the main screw, and the lowest point of the inserted middle core pin was positioned at the same level with the main screw; in EPS group, the tip of EPS expanded markedly and formed a claw-like structure; in CICPS group, the bone cement was mainly distributed in the front of the screw and was dispersed in the trabecular bone to form a stable screw-bone cement-trabecular complex. The maximum axial pullout force of YPS, EPS, and CICPS groups was (98.43±8.26), (77.41±11.41), and (186.43±23.23) N, respectively; the maximum running torque was (1.42±0.33), (0.96±0.37), and (2.27±0.39) N/m, respectively; and the maximum periodical anti-bending was (67.49±3.02), (66.03±2.88), and (143.48±4.73) N, respectively. The above indexes in CICPS group were significantly higher than those in YPS group and EPS group (P<0.05); the maximum axial pullout force and the maximum running torque in YPS group were significantly higher than those in EPS group (P<0.05), but there was no significant difference in the maximum periodical anti-bending between YPS group and EPS group (P>0.05).
Conclusion
Compared with EPS, YPS can effectively enhance the maximum axial pullout force and maximum rotation force in the module, which provides a new idea for the design of screws and the choice of different fixation methods under the condition of osteoporosis.
ObjectiveTo compare the safety and accuracy of pedicle screw placement assisted by robot system with freehand pedicle screw placement in upper thoracic surgery.MethodsBetween December 2017 and December 2019, 39 cases with upper thoracic pedicle screw internal fixation were included in the study, including 19 cases in robot group (group A, robot assisted pedicle screw placement) and 20 cases in freehand group (group B, freehand pedicle screw placement). There were 104 screws implanted in group A and 108 screws in group B. There was no significant difference in age, gender composition, body mass index, disease type, number of screws implanted, and segmental distribution between the two groups (P>0.05). The operation time, intraoperative blood loss, and postoperative drainage were recorded and compared between the two groups. CT scan was performed in all patients at 2 days after operation to evaluate the screw accuracy based on the Gertzbein-Robbins grading standard.ResultsThe operation time of group A was significantly longer than that in group B (t=2.759, P=0.009). There was no significant difference in intraoperative blood loss and postoperative drainage between the two groups (t=?0.796, P=0.431; t=?0.814, P=0.421). At 2 days after operation, according to Gertzbein-Robbins grading standard, the accuracy of pedicle screw implantation in group A were grade A in 94 screws, grade B in 9 screws, and grade C in 1 screw; and in group B were grade A in 72 screws, grade B in 26 screws, grade C in 9 screws, and grade D in 1 screw; the difference between the two groups was significant (Z=4.257, P=0.000). The accuracy rate of group A was 99.04%, and that of group B was 90.74%, showing significant difference (χ2=7.415, P=0.006).ConclusionCompared with traditional freehand pedicle screw placement, robot-assisted pedicle screw placement significantly improves the accuracy and safety of screw placement without increasing the bleeding and postoperative drainage.
Objective To explore the feasibility and the effectiveness of the accurate placement of lumbar pedicle screws using three-dimensional (3D) printing navigational templates in Quadrant minimally invasive system. Methods The L1-5 spines of 12 adult cadavers were scanned using CT. The 3D models of the lumbar spines were established. The screw trajectory was designed to pass through the central axis of the pedicle by using Mimics software. The navigational template was designed and 3D-printed according to the bony surface where the soft tissues could be removed. The placed screws were scanned using CT to create the 3D model again after operation. The 3D models of the designed trajectory and the placed screws were registered to evaluate the placed screws coincidence rate. Between November 2014 and November 2015, 31 patients with lumbar instability accepted surgery assisted with 3D-printing navigation module under Quadrant minimally invasive system. There were 14 males and 17 females, aged from 42 to 60 years, with an average of 45.2 years. The disease duration was 6-13 months (mean, 8.8 months). Single segment was involved in 15 cases, two segments in 13 cases, and three segments in 3 cases. Preoperative visual analogue scale (VAS) was 7.59±1.04; Oswestry disability index (ODI) was 76.21±5.82; and the Japanese Orthopaedic Association (JOA) score was 9.21±1.64. Results A total of 120 screws were placed in 12 cadavers specimens. The coincidence rate of placed screw was 100%. A total of 162 screws were implanted in 31 patients. The operation time was 65-147 minutes (mean, 102.23 minutes); the intraoperative blood loss was 50-116 mL (mean, 78.20 mL); and the intraoperative radiation exposure time was 8-54 seconds (mean, 42 seconds). At 3-7 days after operation, CT showed that the coincidence rate of the placed screws was 98.15% (159/162). At 4 weeks after operation, VAS, ODI, and JOA score were 2.24±0.80, 29.17±2.50, and 23.43±1.14 respectively, showing significant differences when compared with preoperative ones (t=14.842,P=0.006;t=36.927,P=0.002;t=–36.031,P=0.001). Thirty-one patients were followed up 8-24 months (mean, 18.7 months). All incision healed by first intention, and no complication occurred. During the follow-up, X-ray film and CT showed that pedicle screw was accurately placed without loosening or breakage, and with good fusion of intervertebral bone graft. Conclusion 3D-printing navigational templates in Quadrant minimally invasive system can help lumbar surgery gain minimal invasion, less radiation, and accurate placement.
Objective To evaluate the therapeutic effects of expandable pedicle screw (EPS) combined with interbody fusion cage on lumbar spondylolisthesis. Methods From June 2004 to March 2008, 23 patients with lumbar spondylolisthesiswere treated, including 9 males and 14 females aged 24-72 years old (average 48.7 years old). The course of the disease varied from 6 months to 6 years (average 30.4 months). There were 18 cases of degenerative spondylol isthesis and 5 of isthmic spondylolisthesis, including 1 case at L3,4 level, 14 at L4,5 level, and 8 at L5 and S1 levels. There were 17 cases of grade I, 4 of grade II, and 2 of grade III (including 1 case of recurrent L5 spondylolysis) according to Meyerding classification system. Posterior lumbar interbody fusion was performed using 48 PLIVIOS interbody fusion cages, and spondylolisthesis reduction and internal fixation were conducted using 84 pieces of EPS. The indications for use of EPS were initial operation with bone mass reduction or osteoporosis, reoperation of previous pedicle instrumentation, intraoperative screw relocation, sacral anchoring, and construct reinforcement. Cl inical outcomes, radiographic reduction of spondylol isthesis and bone fusion of lumbar interbody were evaluated based on JOA score, Boxall index, and Cook criteria. Results The incision healed by first intension in all cases except for one revision case that suffered from postoperative cerebrospinal fluid leakage and obtained delayed-healing without infection 23 days after operation using conservative treatment. No operative compl ications such as nerve and organ injuries were found.All cases were followed up for 12-39 months (average 17.8 months). X-ray exams of spine AP, lateral, fully extended position and fully flexed position view showed all 84 EPS were fully expanded within vertebral body. The improvement rate of JOA at the final follow-up visit was markedly effective in 14 cases, and effective in 5 cases, and noneffective in 4 cases, with a total effective rate of 82.61%. Anatomic reduction was achieved in 14 cases, improvement was obtained in 6 cases, no improvement was observed in 3 cases, and the reduction rate was 86.69%. Lumber interbody fusion was achieved in 20 cases, fixation was achieved in 2 cases, failure was observed in 1 cases, and the fusion rate was 86.69%. Conclusion EPS in complex with interbody fusion cage provides effective reduction, internal fixation and interbody fusion for the reconstruction of lumbar spondylolisthesis.
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.
Objective To explore some operative problems of correcting paralytic scoliosis(PS) by using vertebral pedicle screwsrods system. Methods From May 2000 to May 2005, 18 patients with PS were corrected by screwsrods system which were made of titanium alloy.There were 10 males and 8 females, aging from 11 to 26 years. The primary disease included poliomyelitis in 13 patients and myelodysplasia (MS) in 5 patients (2 cases for second correction) with scoliosis of an average 85° Cobb angle (55-125°). The pelvic obliquity was found in all patients with an average 24° angle (355°).Of the 18 patients,3 cases were given perioperative halo-pelvic traction, 2 cases were given vertebral wedge osteotomy and correction and fixation, the other patients were purely underwent the treatment of pedicle screwrods system implants. Fusion segment at operation ranged from 6 to 15 sections, applied screws the most was 16,the fewest was 6. Results There were no wound infections and neurologic complications, all wounds healed by the first intention. Allscoliosis obtained obvious correction (P＜0.001), the correction rate averaged 52.95% (44%-81%); the majority of lumbar kyphosis and pelvic obliquity were apparently corrected. The average clinical follow-up (16 cases) was 21 months(6-36 months),there was no implants failure. One patient with MS had a worse Cobb magnitude, the other patients had no curve progression (P＞0.05). Conclusion The use of vertebral pedicle screwsrods fixation to multiple vertebral bodys and short segment fusion for PS, the treatment method is reliable and the outcome is satisfactory. While performing the correcting operative procedures, the spinal, pelvic and lower extremity deformities and functions should be all considered as a whole.
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 evaluate the fixation strength of expansive pedicle screw (EPS) at different bone mineral density (BMD) levels, further to provide theoretical evidence for the clinical application of the EPS in patients with osteoporosis.
Methods
Fresh human cadaver spines (T12-L5 spines) were divided into 4 levels: normal BMD, osteopenia, osteoporosis, and severe osteoporosis according to the value of BMD, 12 vertebra in each level. Conventional pedicle screw (CPS) or EPS was implanted into the bilateral vertebra in CPS group and EPS group, respectively, 12 screws in each group per BMD level. Screw pullout tests were conducted. The maximum pullout strength, stiffness, and energy absorption were determined by an AG-IS material testing machine with constant rate of loading in a speed of 5 mm/ min.
Results
With the decline of BMD from normal to severe osteoporosis level, the maximum pullout strength and the stiffness correspondingly declined (P lt; 0.05). In CPS group, the energy absorption gradually decreased (P lt; 0.05); in EPS group, significant difference was found between other different BMD levels (P lt; 0.05) except between normal BMD and osteopenia and between osteoporosis and severe osteoporosis (P gt; 0.05). At the same BMD level, the maximum pullout strength of EPS group was significantly larger than that of CPS group (P lt; 0.05); the stiffness of EPS group was significantly higher than that of CPS group (P lt; 0.05) except one at normal BMD level; and no significant difference was found in the energy absorption between 2 groups (P gt; 0.05) except one at osteopenia level. No significant difference was found in maximum pullout strength, stiffness, and energy absorption between EPS group at osteoporosis level and CPS group at osteopenia level (P gt; 0.05); however, the maximum pullout strength, stiffness, and energy absorption of EPS group at severe osteoporosis level were significantly lower than those of CPS group at osteopenia level (P lt; 0.05).
Conclusion
Compared with CPS, the EPS can significantly improve the fixation strength, especially in patients with osteopenia or osteoporosis.
