Objective:By comparing the clinical effect of minimally invasive hollow screw internal fixation Assisted by orthopedic robot (TiRobot) and O-arm navigation in the treatment of pelvic fractures, and practicability and security of both treatments were evaluated.Methods:Retrospective analysis of data of 42 cases of Tile C type pelvic fractures was employed during June 2017 to June 2020. Among them, 32 cases, twenty-four men, eight women, aged 34±6.2 years (range 24-68 years), were treated with percutaneous screw fixation guided by O-arm X wire instrument. According to Tile classification, there were 3 cases of C1.1 type, 8 cases of C1.2 type and 21case of C1.3 type. According to the Denis classification of sacral fractures, 17 cases were in zone I, and 8 cases in zone II. Ten patients, eight males and two females, aged 36±5.2 years (range 19-62 years) were treated by percutaneous screw fixation assisted by orthopedic robot. According to Tile classification, there were 1 case of C1.1 type, 2 cases of C1.2 type and 7 cases of C1.3 type. According to the Denis classification of sacral fractures, there were 5cases in zone I, 2 cases in zone II. For those who got obviously displaced pelvic fractures, Starr frames were used and then internal fixation was used to fix pelvic anterior ring and posterior ring injury respectively. Based on the times of needle adjustments, intraoperative fluoroscopy time, good screw position and incidence of complications two groups were statistically analysed. Matta score was employed to evaluate the quality of fracture reduction, while the Majeed score was employed to evaluate the clinical efficacy. Through the two groups of cases guide needle adjustment times, intraoperative fluoroscopy time, screw position excellent and good rate and the incidence of complications, which were statistically analyzed.Results:All screw positions were confirmed by CT scan after operation. The average time required for each screw placement of the O-arm group was 7.36±2.63 s, of the robot group was 6.80±3.20 s, so difference was not statistically significant ( P<0.05). An average of screw adjustments per one screw was 1.56±0.02 times by O-arm, and by the robot group was 0.34±0.06 times, so differences between the two groups were statistically significant ( P>0.05). The average operating time of O-arm group was 53.86±15.06 min, while the robot group was 52.52±15.14 min, so differences between the two groups were not statistically significant ( P>0.05). Position distribution of screw placement in two groups, all screws in O-arm group of position evaluations were excellent, excellent rate was 100%, all screw position evaluations by robot were excellent, excellent rate was 100%, so difference in screw distribution between the two groups was not statistically significant ( P>0.05). All cases were followed up for 6-12 months. Fracture healing time: 34.6±8.6 weeks for O-arm group, 33.4±9.4 weeks for robot group. Comparison between the two groups was not statistically significant ( P>0.05). Majeed score of O-arm group was 55-87, including Excellence of 17 cases, goodness of 9, fairness of 6. The rate of excellence and goodness was 81.2%, while robot group was 76-95, and that were excellent 7 cases,1 good, and the excellent and good rate was 80%, there was no significant difference between Matta and Majeed score between the two groups ( P>0.05). The incidence of complications between the two groups were no statistically significant ( P>0.05). Conclusion:Orthopedic robot system and O-arm navigation system assisted by percutaneous hollow screw fixation treatment of pelvic anterior and posterior ring injury, which are accurate, safe, minimally invasive, can reduce radiation damage to patients and surgeons. The efficacy were satisfactory. Both treatments are ideal for minimally invasive treatment of pelvic fractures, and the orthopedic robot have advantages of being programmed, standardized, stable and it’s learning curve is shorter.

Objective:To investigate the feasibility and clinical efficacy of percutaneous screw fixation for acetabular anterior column fracture with laser-assisted axial fluoroscopy.Methods:Data of 20 patients (22 sided) with acetabular anterior column fracture treated by percutaneous screw fixation with laser-assisted axial fluoroscopy from January 2017 to December 2018 were retrospectively analyzed. There were 11 males and 9 females with an average of 42.1±3.2 years (range, 24-68 years). There were 7 cases of unilateral acetabular anterior column fracture, 2 cases of bilateral acetabular anterior column fracture (4 sides), 7 cases of anterior column with ipsilateral sacral fracture, and 4 cases of anterior column with sacroiliac joint injury. There were 3 hips of Area I, 6 Area II, 13 Area III of acetabular anterior column fractures according to Nakatani partition. The time from injury to surgery was 5 days (range, 3-11 days). All patients with acetabular anterior column fractures were fixed by percutaneous screw fixation with laser-assisted axial fluoroscopy, and patients with sacral fracture or sacroiliac joint injury were fixed by percutaneous sacroiliac screws with Starr frame-assisted reduction. The time of operation, the number of intraoperative fluoroscopy and the amount of intraoperative bleeding were recorded. Matta scoring criteria were used to assess fracture reduction quality, and hip function was assessed at the last follow-up according to the modified Merle D' Aubigné and Postel scoring system.Results:The average operative time was 22±10 min (range, 20-40 min) with an average times of intraoperative fluoroscopy of 30±8 times (range, 21-45 times), and the amount of intraoperative blood loss was 20±5 ml (range, 10-40 ml). 20 patients were followed up after operation for a period of 14±3.1 months (range, 12-18 months). The quality of postoperative fracture reduction was assessed according to the Matta acetabular fracture reduction criteria: anatomical reduction in 18 hips, satisfactory reduction in 2 hips, unsatisfactory reduction in 2 hips, with an excellent and good rate of 91% (20/22). The fracture healing time was 13±2.2 weeks (range, 11-16 weeks). At the lastest follow-up, hip function was assessed according to the modified Merle D' Aubigné and Postel scoring system: excellent 18, good 3, fair 1, and the satisfactory rate was 95%(21/22). No major neurological, vascular injury, wound infection and ectopic ossification were found during follow-up.Conclusion:Using laser-assisted axial fluoroscopy percutaneous screw to treat acetabular anterior column fracture, the operation is simple. And there is low risk to damage important blood vessels and nerves. This method can shorten the operation time of acetabular anterior column fracture, reduce the amount of blood loss during the operation, and the outcome is satisfactory.

Objective To investigate the feasibility and short term clinical efficacy of early minimally invasive treatment of complex pelvic trauma with Starr reduction frame combined with O?arm navigation system. Methods From June 2017 to De?cember 2018, thirty two patients with Tile C complex pelvic fractures were prospectively divided into two groups according to the random number table. The open treatment group included 17 cases (open reduction and internal fixation group; 10 males and 7 fe?males, age 24-60 years, average 37±6.5 years;according to Tile classification, 8 cases of C1 type, 8 cases of C2 type and 1 case of C3 type; according to the Denis classification of sacral fractures, 9 cases in zone I, 6 cases in zone II and 2 cases in zone III). The combined treatment group included 15 cases (Starr reduction frame group combined with O?arm navigation system, 8 males and 7 females, age 32-57 years, average 40±5.2 years; according to Tile classification, 8 cases of C1 type, 6 cases of C2 type and 1 case of C3 type; according to the Denis classification of sacral fractures, 8 cases in zone I, 5 cases in zone II and 2 cases in zone III). The ilioinguinal and Stoppa approaches were used in the open treatment group, and the anterior and posterior ring injuries were fixed with reconstruction plate screws and hollow screws, respectively. In the combined treatment group, starr frame was used to assist reduction, combined with "O" arm navigation technique, infix internal fixation frame, superior pubic branch screw, sacro?ilium screw were used to fix the anterior and posterior ring injury. The quality of pelvic fracture reduction was evaluated by the Matta scoring system, and the Majeed score was used to evaluate the clinical efficacy. Results All patients were followed up for 6 to 12 months. The hospitalization time (45±11 d), operation time (220.0±49.4 min) and fracture healing time (24.0±5.6 weeks) in the open treatment group were longer than those in the combined treatment group (21±9 d, 180.0±24.2 min, 16.1±3.8 weeks), and the intraoperative blood loss (820.0±140.4 ml) was significantly higher than that in the combined treatment group (24.0±10.4 ml) (t=6.651, 2.772, 6.128, 22.874; all P<0.05). According to Matta scoring system, in the open treatment group, there are 8 excellent cases, 6 good cases, 2 fair cases, 1 poor case, thus the excellent and good rate was 82.4%(14/17). While 9 cases were excellent, 5 good, 1 fair, and the excellent and good rate was 93.3% (14/15) in the combined treatment group. At the latest follow?up, Majeed score was 51-85 points in the open treatment group, including excellent in 8 cases, good in 6 cases, fair in 2 cases, poor in 1 case, thus the excellent and good rate 82.4% (14/17), and the Majeed score was 75-95 points in the combined treatment group, includ?ing excellent in 9 cases, good in 5 cases, fair in 1 case, thus excellent and good rate 93.3% (14/15). There was a statistically signifi?cant difference between the two groups of Matta score and Majeed score (χ2=0.034, 0.040; P<0.05). Surgical infection occurred in 4 cases in the open treatment group and healed after debridement and treatment with sensitive antibiotics. The incidence of compli?cations was 23.5% (4/17). In the combined treatment group, 2 cases had anterolateral thigh skin sensory loss after operation, and the symptoms were relieved after mannitol, mecobalamine treatment and removal of internal fixations. One patient had hematoma of the gluteus maximus muscle after operation. The result of angiography showed that the INFIX screw was too long and perforated near the foramen of the ischium, resulting from the injury of the superior gluteal artery. After stopping the use of anticoagulant, in?travenous infusion of tranexamic acid, blood transfusion, etc., the patient was cured and discharged from hospital. The incidence of complications was 20.0% (3/15). There was no significant difference in the incidence of complications between the two groups. Conclusion With the help of starr reduction frame, the early reduction and minimally invasive treatment of pelvic fracture can be realized, and the amount of intraoperative bleeding can be reduced. The combined application of "o" arm navigation can im?prove the accuracy and safety of sacroiliac screw and anterior column screw placement, reduce the radiation dose and frequency of operators and patients, shorten the operation time and improve the curative effect.