Objective To explore the feasibilities, methods, outcomes and indications of atlas pedicle screw system fixation and fusion for the treatment of upper cervical diseases. Methods From October 2004 to January 2006, 17 patients with upper cervical diseases were treated with atlas pedicle screw system fixation and fusion. There were 13 males and 4 females, ageing 19 to 52 years. Of 17 cases, there were 14 cases of atlantoaxial dislocation(including 3 cases of congenital odontoid disconnection，4 cases of old odontoid fracture，2 cases of new odontoid fracture(typeⅡC), 3 cases of rupture of the transverse ligament, and 2 cases of atlas fracture； 2 cases of tumor of C2; 1case of giant neurilemoma of C2,3 with instability after the resection oftumors. JOA score before operation was 8.3±3.0. Results The mean operative time and bleeding amount were 2.7 hours (2.1-3.4 hours) and 490 ml (300-750 ml) respectively. No injuries to the vertebral artery and spinal cord were observed. The medial-superior cortex of lateral mass was penetrated by 1 C1 screw approximately 3 mmwithout affecting occipito-atlantal motions. All patients were followed up 3-18 months. The clinical symptoms were improved in some extents and the screws were verified to be in a proper position, no breakage or loosening of screw and rob occurred. All patients achieved a solid bone fusion after 3-6 months. JOA score 3 months after operation was14.6±2.2. JOA improvement rates were 73%-91%(mean 82%). Conclusion The atlas pedicle screw system fixation and fusion is feasible for the treatment of upper cervical diseases and has betteroutcomes, wider indications if conducted properly.
Objective To assess the treatment effect of intra-articular fracture with absorbable screws and rods.Methods From June 1998 to August 2004， 35 patients with intra-articular fracture were treated by absorbable screws and rods made of self-reinforcedpolyglycolicacid (SR-PGA) and self-reinforcedpoly-L-Lacticacid (SR-PLLA). Of 35 patients, 30 were males and 5 were females (aged from 4 to 62 years). All cases had intra-articular or periarticular fracture. The interval between injury and operation was 3 hours to 29 days. Fracture were fixed with full thread screws of SR-PGA in 9 cases, with tensile screws of SR-PLLA in 26 cases, with rods of SR-PLLA in 15 cases. Bone traction orplaster external fixation were carried out postoperatively. Results The patients were followed from 3 months to 60 months with an average of 28 months．The wounds healed by first intention, and the healing time of bone was 1－3 months. No dislocation, infection and local effusion occurred. Functional recovery was satisfactory．According to AASO articular function standard, the results were excellentin 26 cases, good in 7 cases, fair in 1 case, and poor in 1 case; the total excellent and good rate was 94.3%. Conclusion Internal fixationof absorbable screws and rods are a perfect procedure in treating intraarticular and periarticularfracture, which can avoid the pain of taking out internal fixation materials because of second operation．
Objective To explore the reduction and support effect of the subchondral screw compression technique for residual or secondary collapse of the lateral tibial plateau during operation. Methods Between January 2020 and June 2021, 11 patients with residual or secondary collapse of the lateral tibial plateau during operation were treated with the subchondral screw compression technique. There were 6 males and 5 females, aged 52.3 years old (range, 27-64 years). The fractures were caused by traffic accident in 10 cases and falling from height in 1 case and located at the left knee in 6 cases and the right knee in 5 cases. According to Schatzker classification, there were 5 cases of type Ⅱ fractures, 4 cases of type Ⅲ fractures, and 2 cases of type Ⅴfractures. According to the three columns classification, there were 5 cases of lateral column, 4 cases of lateral column and posterior column, and 2 cases of three columns. The time from injury to operation was 4.5 days (range, 3-7 days). During the follow-up, X-ray films were obtained and the Rasmussen standard was used to evaluate the quality of fracture reduction, meanwhile fracture healing was observed. The medial proximal tibial angle (mPTA), posterior tibial slope angle (pTSA), and articular surface collapse were measured at immediate and 12 months after operation. The knee joint range of motion was evaluated at last follow-up, and the knee joint function was evaluated using the Hospital for Special Surgery (HSS) score. Results All operations were successfully completed, with a mean operation time of 71.4 minutes (range, 55-120 minutes), and a mean hospital stay of 8.0 days (range, 5-13 days). The incisions all healed by first intention, without complications such as infection, flap necrosis, or vascular and nerve injury. All patients were followed up 16.5 months on average (range, 12-24 months). X-ray films showed that the fracture reduction score was 14-18 (mean, 16.7) according to Rasmussen score criteria; and 5 cases were rated as excellent and 6 as good. All fractures healed clinically with a mean clinical healing time of 14.9 weeks (range, 12-16 weeks), and there was no complications such as plate or screw loosening. At 12 months after operation, the mPTA and pTSA were (87.5±1.7)° and (6.2±3.1)°, respectively; there was no significant difference when compared to the values at immediate after operation [(87.6±1.8)° and (6.5±3.1)°] (P>0.05). The articular surface of the tibial plateaus was effectively supported, and it collapsed again by 0-1.0 mm at 12 months, with an average of 0.4 mm. At last follow-up, the knee joint range of motion was 115°-135° (mean, 126.8°) and the HSS score for knee joint function was 87-98 (mean, 93.9). Five patients underwent secondary operation to remove the internal fixator at 12-18 months after operation.ConclusionThe subchondral screw compression technique is helpful for the reduction of residual or secondary collapse of the lateral tibial plateau during operation, and can provide good support for osteochondral blocks.
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.
ObjectiveTo investigate the effectiveness of individual percutaneous cannulated screws fixation of computer-assisted design combined with three-dimensional (3D) guide plate by comparing with cast immobilization and open internal fixation for treatment of Herbert type Ib scaphoid fracture. MethodsBetween January 2010 and June 2015, 56 patients with fresh Herbert type Ib scaphoid fracture were treated with cast immobilization in 16 cases (external fixation group), with open reduction and internal fixation in 20 cases (open reduction group), and with individual percutaneous cannulated screws fixation of computer-assisted design combined 3D guide plate in 20 cases (minimal invasion group). There was no significant difference in gender, age, injury cause, side, disease duration, and classification of fractures between groups P>0.05).The time of bone union, bone nonunion rate, return-to-work time, wrist range of motion (ROM), and Mayo function score were recorded and compared. ResultsPrimary healing of incision was obtained in open reduction group and minimally invasion group, without related complications. The cases were followed up 10-24 months (mean, 16.6 months). The time of bone union and return-to-work time of minimal invasion group were significantly shorter than those of the other 2 groups (P<0.05), and the rate of bone nonunion was significantly lower than that of the other 2 groups (P<0.05). At last follow-up, the wrist ROM of minimal invasion group[(104.40±3.46)°] was significantly larger than that of external group[(94.20±2.42)°] and open reduction group[(96.40±2.66)°] (P<0.05). According to Mayo function score, the results were excellent in 6 cases, good in 5 cases, fair in 2 cases, and poor in 3 cases in external fixation group, with an excellent and good rate of 69%; the results were excellent in 9 cases, good in 7 cases, fair in 2 cases, and poor in 2 cases in open reduction group, with an excellent and good rate of 80%; the results were excellent in 16 cases, good in 3 cases, and fair in1 case in minimal invasion group, with an excellent and good rate of 95%; there was significant difference in excellent and good rate among groups (P<0.05). ConclusionIndividual percutaneous cannulated screws fixation of computer-assisted design combined with 3D guide plate has satisfactory effectiveness in the treatment of Herbert type Ib scaphoid fractures, with the advantages of mini-invasion, high accuracy, high rate of bone union, less complication, early return-to-work time.
ObjectiveTo compare the parameters of screw implantation in capitolunate arthrodesis between the 2nd and 3rd metacarpal bones and via the distal dorsal capitate bone approach based on CT images of the normal wrist, and provide reference for the selection of surgical approaches and planning of screw insertion trajectory. MethodsCT data of 50 patients who met the criteria between February 2022 and April 2022 were selected as the study objects. There were 30 males and 20 females, and the age ranged from 18 to 69 years (mean, 37 years). The normal wrist alignment was conformed in all CT images. All CT data from the unilateral wrist of the patients was imported into Mimics Medical 20.0 software to construct a three-dimensional plane model, in which a virtual 3.5 mm screw was implanted between the 2nd and 3rd metacarpal bones and via the distal dorsal capitate bone approach. The angle between screw and coronal, sagittal, and transverse planes, the total length of the screw, the length of the screw in the lunate bone and the capitate bone were measured. The ratios of the length of the screw in capitate bone to the length of the long axis of the capitate bone, the length of the screw in lunate bone to the length of the long axis of the lunate bone, and the length of screw in lunate bone to the length of the screw in capitate bone were calculated. Assuming that the result of screw implantation between the 2nd and 3rd metacarpal bones was better than that via the distal dorsal capitate bone approach, the difference in length of the screw in the lunate bone between the two approaches was calculated, and the superiority test was performed. ResultsCompared with the distal dorsal capitate bone approach, the total length of the screw increased, the length of the screw in the capitate bone decreased, and the length of the screw in the lunate bone increased, the angle between the screw and coronal plane decreased, the angles between screw and sagittal, transverse planes increased after the screw was implanted between the 2nd and 3rd metacarpal bones. And the ratio of the length of the screw in capitate bone to the length of the long axis of capitate bone decreased, the ratio of the length of the screw in lunate bone to the length of the long axis of lunate bone increased, and the ratio of the length of the screw in lunate bone to the length of the screw in capitate bone also increased. All the differences were significant (P<0.05). The difference in the length of the screw in the lunate bone between the two approaches was 1.86 mm [95%CI (1.54, 2.18) mm], which was greater than the superiority margin (1.35 mm). The superiority hypothesis was supported. ConclusionCompared with the distal dorsal capitate bone approach, the screws implanted between the the 2nd and 3rd metacarpal bones in the capitolunate arthrodesis are longer in lunate bone and more vertical to the articular surface of the capitolunate joint. Theoretically, the capitolunate joint are more firmly fixed.
Objective To evaluate the fixation technique of using the cervical lateral mass plate in the cervical posterior approach operation. Methods Eight patients in this group were admitted from September 2001 to November 2006. Among the 8 patients, there were 6 males and 2 females, with their ages ranging from 28 to 78 years. Cervical vertebral fracture with dislocation was found in 4 patients, C2 spinal cord injury in 1, C1 fracture in 1, cervical spinal stenosis in 1, and C2-5 spinal cord neurofibroma in 1. Muscle strength 3-4. TheFrankel grading system was usedin 6 patients with traumatic injury. Before operation, Grade C was observed in 2patients，Grade D in 3，and Grade E in 1. All the operations were performed according to requirements of the Margel’s method. We positioned 40 screws in all the patients, including 4 screws at C2，6 screws at C3，12 screws at C4，4 screws at C5，4 screws at C6，2 screws at C7，and 6 screws at T1. Results The followingup for an average of 14.1 months (range,645 months) revealed that there was no malposition of the screws in the patients. One of the 8 patients developed spinal instability in the fixed segment at 3 months after operation. The headchestbrace was applied to the patient for 3 months, and the spinal fusion was achieved. The further followingup to 45 months indicated that there was no instability occurring. The remaining patients recovered to their spinal stability by the spinal fusion. The patients also recovered in their neurological function after operation. The Frankel assessment showed that 1 patient had Grade E, 3 from Grade D to Grade E, 1 from Grade C to Grade D, and 1 from Grade C to Grade E. Conclusion The cervical lateral mass plate fixation can provide the immediate and b segmental immobilization for the good cervical spine stability.
ObjectiveTo investigate the distance between the screw-out point and the middle sacral artery, and evaluate the safety when the S1 pedicle screw placed by the three cortical fixation techniques.MethodsFrom March to June 2018, randomized CT scan data of 98 adult pelvic angiography were selected to measure the distance from the middle sacral artery to the anterior edge of the vertebral body (a) and the distance from the middle sacral artery to the midline of the vertebral body (b). S1 screw entry point was set as the intersection of lines where extension of S1 facet joint inferior margin and lateral margin cross over. Introversion angles of 10, 15, 20, and 25° were used; the distance between the screw insertion point and the middle sacral artery (d) was measured.ResultsThe middle sacral artery was usually located on the left side of the upper endplate plane of S1. The distance a was (5.40±2.95) mm in 49 males and (4.43±2.32) mm in 49 females, and the difference between the males and females was not statistically significant (t=1.818, P=0.72). The distance b was (12.07±5.42) mm in 45 males and (14.12±4.88) mm in 48 females, and the difference between the males and females was not statistically significant (t=–1.914, P=0.59). The distance d was (12.67±6.00), (9.40±5.17), (7.50±3.76), and (8.10±3.64) mm when the nail was placed at a common internal inclination of 10, 15, 20, and 25°. The differences in the distance d at a common internal inclination of 10° vs. 15°, 10° vs. 20°, 10° vs. 25°, and 15° vs. 20° were all statistically significant (t=16.828, 11.609, 6.073, 6.254; P<0.008 3); there was no statistically significant difference in that at 15°vs. 25°, or 20° vs. 25° (t=2.034, –1.723; P>0.05).ConclusionBy analyzing the relationship between the middle sacral artery and the upper endplate plane of the S1 vertebra, the risk of middle artery injury is small while the biomechanical stability of the screw is increased when using the Lenham method.
Objective To employ spinal virtual surgery system (SVSS) for preoperative planning of thoracolumbar pedicle screw fixation, and to establ ish the measurement method for pedicle screw-related parameters. Methods Eight thoracicand lumbar spine specimens (T11-L3) were selected. First of all, SVSS was used for the preoperative planning of pedicle screw and the parameters of both sides of pedicle were measured in every vertebral segment, including angle of axial view (Aa), angle of sagittal view (As), x-direction entrance (XE), total pedicle length of axial view (TLa), total pedicle length of sagittal view (TLs), pedicle height (PH), pedicle width (PW), and pedicle spongy width (PSW). Then the corresponding parameters of the right and left pedicle screws of the specimens were measured actually. Finally, its accuracy was verified by comparing the data by virtual measurement and actual measurement. Results There was no significant difference in the parameters of virtual measurement (Aa, As, TLa, TLs, XE, PW, PSW, and PH) and actual measurement (Aa, As, TLa, XE, PW, PSW, and PH) between the right and left sides (P gt; 0.05). Except XE of the L3 vertebral segment and PSW of T11 and T12 vertebral segments (P lt; 0.05), the differences in other parameters of other segments were not significant (P gt; 0.05). Conclusion After statistical analysis and comparison, the feasibil ity of preoperative planning of thoracolumbar pedicle screw fixation and the accuracy of the measurement of the SVSS is verified.
Objective To evaluate the effectiveness of lumbopelvic fixation using the combination of closed multi-axial screws (CMAS) iliosacral fixation system and the posterior segmental spinal fixation for unstable sacral fractures. Methods Between January 2013 and November 2014, 25 patients (39 sides) with unstable sacral fractures were treated with lumbopelvic fixation using the combination of CMAS iliosacral fixation system and the posterior segmental spinal fixation. There were 17 males and 8 females, aged 19-55 years (mean, 33.9 years). The causes were traffic accident injury in 15 cases, falling injury from height in 8 cases, and crushing injury in 2 cases. The interval of injury and operation was 1-13 days (mean, 3.5 days). Fracture was classified as Denis type I in 2 sides, type II in 20 sides, and type III in 17 sides; nerve injury was rated as Gibbons grade I in 2 cases, grade II in 2 cases, grade III in 7 cases, and grade IV in 9 cases. The reduction quality was evaluated by Matta criterion, the clinical function outcome by Majeed, and nerve function by Gibbons criterion. Results The average operation time was 110 minutes (range, 80-150 minutes). The average blood loss was 570 mL (range, 250-1 400 mL). Superficial wound infection occurred in 2 patients, and was cured after debridement and antibiotic therapy. All patients were followed up for an average of 18 months (range, 15-22 months). Postoperative X-ray and CT examination showed clinical healing of sacral fractures at 8-12 weeks after operation (mean, 10 weeks). The mean removal time of internal fixation was 13 months (range, 12-20 months). No screw loosening and fracture, adhesion of internal fixation to surrounding tissue, and obvious electrolysis phenomenon occurred. According to Matta criterion, reduction was rated as excellent in 32 sides, good in 6 sides, fair in 1 side, and the excellent and good rate was 97.5%. According to Majeed functional scoring at last follow-up, the mean score was 84.7 (range, 64-98); the results were excellent in 18 cases, good in 5 cases, and fair in 2 cases, and the excellent and good rate was 92.0%. The nerve function was significantly improved when compared with preoperative one; nerve injury was rated as Gibbons grade I in 8 cases, grade II in 8 cases, grade III in 3 cases, and grade IV in 1 case. Conclusion Lumbopelvic fixation using the combination of CMAS iliosacral fixation system and the posterior segmental spinal fixation is a relatively effective fixation for unstable sacral fractures. Not only is the fracture fixation rigid for early full weight-bearing, but also nerve decompression can be performed which facilitates nerve function recovery.