Objective To investigate the clinical results of minimally invasive fixation of the sacroiliac triangle for vertically unstable pelvic posterior ring injury. Methods A retrospective study was conducted of 20 patients who had been treated for vertically unstable pelvic posterior ring from January 2014 to August 2016. They were 12 males and 8 females, aged from 20 to 58 years ( average, 35 years ) . According to Tile classification for pelvic fractures, there were 4 cases of type C1. 1, 6 cases of type C1. 2, 7 cases of type C1. 3 and 3 cases of type C2. Their posterior rings were treated by fixation through posterior paraspinal approach with S1-iliac pedicle screws plus percutaneous sacroiliac screws, and their anterior rings by closed reduction and internal fixation with cannulated screws, Infix or plate following open reduction. The incision length, operation time and intraoperative blood loss were recorded. Postoperative reduction quality was assessed by Matta radio-logical criteria and pelvic function by Majeed criteria at the final follow-ups. Results Altogether 20 fixation systems of S1-iliac pedicle screws and 37 sacroiliac joint screws were inserted in this series. The length of incision ranged from 5. 5 to 7. 6 cm ( average, 6. 2 cm ) , the operation time from 89 to 130 minutes ( average, 98 minutes) and the intraoperative blood loss from 110 to 320 mL (average, 195 mL). According to Matta ra-diological criteria, reduction was excellent in 13, good in 5 and fair in 2 cases, with an excellent and good rate of 90％. The follow-up time for the 20 patients ranged from 6 to 15 months ( average, 9 months ) . The healing time ranged from 10 to 14 weeks ( average, 12. 5 weeks ) . At the final follow-ups, X-ray and CT three-dimensional reconstruction showed fine fracture union. By the Majeed criteria, the pelvic function was excellent in 11 cases, good in 5, fair in 3, and poor in one, with an excellent and good rate of 80％. No loosening, breakage or pull-out of pedicle screws or sacroiliac screws happened. Conclusion Minimally invasive fixation of the sacroiliac triangle for vertically unstable pelvic posterior ring injury can lead to precise placement, quick recovery, small incision and good functional outcome.

Objective To investigate the value of pelvic CT sagittal reconstruction for percutaneous insertion of iliosacral screws.Methods Data of 32 patients who had been treated for pelvic posterior ring injury from June 2015 to March 2017 were retrospectively analyzed.There were 21 males and 7 females,aged from 21 to 75 years (average,43.2 years).According to Tile classification for pelvic fractures,there were 23 cases of type B (type BI in 4,type B2 in 13 and type B3 in 6),and 9 cases type C (type C1 in 6,type C2 in 2 and type C3 in 1).The pelvic CT three-dimensional reconstruction was performed before operation,and the reconstructed layer of CT sagittal position was overlapped,and preset S1,S2 sacroiliac joint hollow.Insert the screws according to the preset needle point and passage under the perspective of C-arm X-ray machine during the operation.In 32 cases of patients,3 cases of type C1,1 case of type C2 and 1 case of type C3 fractures in sacroiliac joint hollow combined with S1-ilium pedicle screw internal fixation,and the rest of 27 patients were treated by iliosacral screws.The time for each screw placement and the times of X-ray projection were recorded.The position of cannulated screw was observed by CT scan and compared with the preset channel after the operation.Postoperative reduction quality was assessed using Matta radiological criteria and Majeed criteria was used at the final follow-ups to evaluate the pelvic function.Results The operations time was ranged from 40 to 240 min (average,130 min);and the blood loss was ranged from 20 to 150 ml (average,80 ml).Altogether 58 iliosacral screws were inserted in 32 patients.The time for each screw placement was ranged from 5 to 15 min (average,9.5 min);and the number for each screw X-ray projection was ranged from 7 to 15 times (average,10.2 times).Postoperative CT scan and vascular ultrasound showed that all the iliosacral screws did not penetrate the cortical bone or damaged the vascular nerves,and the error of the preset channel was from 0 to 5 mm (average,2.2 mm).All fractures healed successfully,and the healing time was 12 to 18 weeks (average,14.2 weeks).According to Matta radiological criteria,reduction was excellent in 26,good in 3 and fair in 3,with an excellent to good rate of 90.6％ (29/32).The follow-up time for the 32 patients was ranged from 6 to 15 months (average,11.3 months).At the latest follow-ups,Xray and CT examination showed fine fracture union and no loosening or breakage of screws in all.By the Majeed criteria,the pelvic function was excellent in 21 cases,good in 8 cases,fair in 3 cases,with a good to excellent rate of 90.6％ (29/32).Conclusion Preoperative pelvic CT sagittal reconstruction for preset of iliosacral screw insertion point,angle and length can achieve more accurate placement,shorter operative time and less time of X-ray projections.

Objective To evaluate the clinical efficacy of our self-made minimally invasive pelvic channel instrument in the treatment of pelvic ring fracture-dislocation.Methods A retrospective study was conducted of the 35 patients who had been treated for pelvic ring fracture-dislocation from December 2015 to November 2017 and fully followed up at Department I of Orthopaedis,Beijing Chaoyang Emergency Rescue Center.They were 25 males and 10 females,aged from 20 to 73 years (average,41.3 years).According to the Tile classification for pelvic fractures,there were 26 cases of type B (type B1 in 8,type B2 in 12 and type B3 in 6) and 9 cases of type C(type C1 in 5,type C2 in 3 and type C3 in 1).Infix or anterior plate combined with percutaneous internal fixation with sacroiliac cannulated screws was used in 11 patients,sacroiliac triangle fixation combined with percutaneous internal fixation with anterior ring cannulated screws in 5 ones,and internal fixation with cannulated screws for anterior and posterior rings in 19 ones.All the channels were established using our self-made minimally invasive pelvic channel instrument for internal fixation with cannulated screws.The time for each screw placement and the number of X-ray projection were recorded.Postoperative reduction,pelvic function at the final follows-ups and complications were recorded.Results A total of 84 cannulated screws were inserted in the 35 patients.The time for each cannulated screw placement ranged from 5 to 13 minutes (average,8.1 minutes);the number of X-ray projection for each screw placement ranged from 7 to 15 times (average,10.3 times).Postoperative CT showed that all the cannulated screws were located in the preset channels.According to the Matta radiological criteria,postoperative reduction quality was excellent in 29,good in 4 and fair in 2,giving a good to excellent rate of 94.3％.The follow-up time for the 35 patients ranged from 6 to 15 months (average,12.3 months).At the final follow-ups,all the patients showed fine fracture union.There was no loosening or breakage of screws in all but one patient in whom one sacroiliac screw became loose 3 months after surgery.By the Majeed criteria,the pelvic function was excellent in 27 cases,good in 5,fair in 3 and poor in one,giving a good to excellent rate of 91.4％.Conclusion Our self-made minimally invasive pelvic channel instrument can be used to establish pelvic channels,leading to more accurate placement,shorter operative time and less X-ray projection.

Objective:To investigate the clinical effect of Infix combined with hollow screws for the treatment of pelvic injuries with pubic symphysis separation in middle-aged and elderly patients.Methods:Data of 8 middle-aged and elderly patients with pelvic injuries due to pubic symphysis separation undergone treatment from January 2017 to December 2020 were retrospectively analyzed.Results:The average operating time of 8 patients was (46.0±6.2)min(range: 40-62min); the average intraoperative blood loss was (32.0±5.6)ml(range: 25-50 ml); the average length of incisions at the iliac screw was(2.6±0.4)cm(range: 2.0-3.5 cm); the average length of incisions at the hollow screw was (1.1±0.3)cm(range: 0.8-1.5 cm); and the average times of fluoroscopy were (36.0±6.0)times(range: 28-52 times). Postoperative X-ray and CT examinations showed that the reduction of the pubic symphysis was good, the inserted iliac screws and cannulated screws were positioned accurately, and the incision healed well.Based on Matta's criteria, postoperative radiological outcomes were evaluated, with 7 cases rated as excellent and 1 as good, giving an excellent to good rate of 100%(8/8). The average followed up time for all 8 patients was (15.0±4.2)months(range: 6-24 months). Pelvic X-ray and CT examinations at the last follow-up showed that the fractures healed well and the pubic symphysis reduction did not fail.Infix and cannulated screws in the pubic symphysis were removed 10-12 weeks after surgery[average: (10.5±0.5)weeks]. According to the Majeed Pelvic Score, 5 cases were rated as excellent, 2 cases as good and 1 as fair, with an excellent to good rate of 87.5%(7/8). One patient had symptoms related to the lateral femoral cutaneous nerve that disappeared after 3 months.One patient developed deep venous thrombosis after surgery, and the filter was placed and removed 10 weeks later.Conclusions:Using Infix plus cannulated screws for the treatment of pelvic injuries in middle-aged and elderly patients with pubic symphysis separation has the advantages of limited trauma and intraoperative blood loss, good fixation and few complications.

Objective:To investigate the clinical efficacy of using INFIX combined with hollow nail in the treatment of anterior pelvic ring injury with symphyseolysis.Methods:Data of 12 patients with anterior pelvic ring injury and symphyseolysis who were treated from January 2016 to December 2018 were retrospectively analyzed. They were 8 males and 4 females with an average age of 39.5 years (range, 23-64 years). There were 4 cases of traffic injury, 3 cases of falling injury and 5 cases of crush injury; all the cases were combined with front and rear crush injury. According to Tile classification for pelvic fractures, there were 6 cases of type B1 , 3 cases of type B3, 1 case of type C1 and 2 cases of type C2. Six cases of B1 and 3 cases of B3 patients used percutaneous inter fixation with sacroiliac joint cannulated screw in posterior ring; 1 case of C1 and 2 cases of C2 used spinal-pelvic fixation. Every patients' operating time of INFIX combined with the pubic symphysis hollow nail , amount of hemorrhage, length of incisions and number of X-ray projections were recorded. Pelvic X-ray and CT scan were taken postoperatively to observe the reduction and screw position. Postoperative reduction quality was assessed using Matta radiological criteria and Majeed criteria was used at the final follow-up to evaluate the pelvic function.Results:The average operating time for 12 patients was 42 min (range, 35-56 min) ; the average amount of hemorrhage was 28 ml (range, 15-40 ml); the average length of incision at INFIX nail placement on both sides were 2.7 cm (range, 2.2-3.5 cm); the average length of incisions at the pubic symphysis hollow nail placement was 0.8 cm (range, 0.6-1.2 cm) and the average number of X-ray projections was 38 times (range, 26-55 times). Postoperative X-ray and CT scan showed that all the hollow screws are located accurately and firmly, and pubic symphysis had good reduction and no infection occurred in the surgical incision at the screw placement site. Postoperative reduction quality was evaluated according to Matta radiological criteria, and there were excellent in 10 and good in 2, giving an excellent to good rate of 100% (12/12). The average follow-up time for the 12 patients was 12 months (range, 6-15 months). At the final follow-up, all patients showed fine fracture union and no looseness of pubic symphysis occurred according to imaging test. According to the Majeed criteria, the pelvic function was excellent in 8 cases, good in 3 cases and fair in 1 case, giving a good to excellent rate of 91.7% (11/12). One case developed symptoms of femoral nerve compression after surgery and returned to normal after removal of the INFIX. Another case had damage to the lateral femoral cutaneous nerve and the symptoms disappeared after three months.Conclusion:Using INFIX combined with hollow nail in the treatment of symphyseolysis can lead to more minimally invasive with excellent postoperative efficacy and markedly reduced the morbidity of complication.

Objective:To investigate the clinical effect of using combined lumbar pelvis fixation device in the treatment of old vertical unstable fracture dislocation of posterior pelvic ring.Methods:Data of 7 patients with old vertical unstable fracture dislocation of posterior pelvic ring admitted and followed up from January 2017 to April 2020 were retrospectively analyzed, including 4 males and 3 females with an average age of 42.4 years old (range, 22-73 years old). There were 3 cases of traffic injury, 3 cases of falling injury and 1 case of tumble injury. According to Tile classification for pelvic fractures, there were 5 cases of type C1, 1 case of type C2 and 1 case of type C3. The average time from fracture to surgery was 5.4 weeks (range, 3-10 weeks). Among the 7 patients, 4 patients' posterior ring fractures were fixed by combined lumbar pelvic triangle fixation, and 3 patients' posterior ring fracture were fixed by combined lumbar pelvic fixation. 4 patients' anterior ring injury were not treated, 2 patients' anterior ring injury were treated by closed cannulated screw and internal fixation, and 1 patient's anterior ring injury was fixed by INFIX and cannulated screw. Every patient's operating time, intraoperative blood loss, length of incision and times of X-ray fluoroscopy were recorded. Pelvic X-ray and CT scan were taken postoperatively to observe the condition of reduction and screw position. Postoperative fracture reduction quality was assessed by Matta radiological criteria and Majeed criteria was used at the final follow-ups to evaluate the degree of functional recovery after pelvic fracture.Results:The average operating time of 7 patients was 143 min (range, 96-205 min); the intraoperative average blood loss was 579 ml (range, 300-1 650 ml); the average length of incisions was 12.9 cm (range, 9-15 cm) and the average time of X-ray fluoroscopy was 27 times (range, 15-52 times). Postoperative X-ray and CT scan showed that the displacements of the posterior rings were reset well and all the hollow screws were located accurately and firmly. Postoperative radiation quality was evaluated according to Matta radiological criteria, and there were 4 cases of excellent, 2 cases of good and 1 case of fair, with an excellent and good rate of 85.7% (6/7). Seven patients had good fracture union. The average followed up time for all 7 patients was 12 months (range, 6-16 months). At the last follow-up, imaging examination showed good reduction of the sacroiliac joint, and the reduction of anterior and posterior rings were not lost. The healing time was 14.2 weeks (range, 12-20 weeks). Majeed score: postoperative 4.90±6.64 points (range, 48-58 points), postoperative 3 months 71.40±7.32 points (range, 67-75 points), postoperative 6 months 84.90±8.14 points (range, 68-96 points), the difference was statistically significant ( F=0.614, P=0.004). Majeed score 6 months after operation showed that 5 cases were excellent, 1 case was good and 1 case was fair, and the excellent and good rate was 85.7% (6/7). Conclusion:Using combined lumbar pelvis fixation device in the treatment of old vertical unstable fracture dislocation of posterior pelvic ring has good reduction quality, high fixed strength and good postoperative effect.