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.

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.

Pre-rheumatoid arthritis （Pre-RA） is the asymptomatic state of rheumatoid arthritis （RA）， and its progression showed complexity， dynamics and significant individual differences. The dynamic prediction model is valuable in identifying individual risks and taking timely preventive and control measures. It is believed that applying the dynamic prediction model to traditional Chinese medicine （TCM） clinical studies of Pre-RA is expected to predict the critical state of Pre-RA to RA， reveal the evolution of Pre-RA， reflect the external authenticity of the TCM clinical studies， and complement the clinical efficacy evaluation method. Accordingly， it is envisioned to construct a dynamic prediction model for Pre-RA progression based on TCM clinical trial data through the dynamic prediction model algorithm， and to apply long-term follow-up cohort data for external validation， thereby providing a basis for scientific warning and clinical decision-making on the evolution of Pre-RA.