Patients
This study was approved by the ethics committee of Bengal Medical College (Number: BYYFY-2019KY03). From February 2019 to June 2020, a total of 124 patients with pelvic fractures were treated in our hospital. The following were the inclusion criteria: 1. Age > 14 years; 2. Injury posterior pelvic ring instability (Tile B or C injury); 3. Sacral fracture: Denis zone 1 or zone 2; 4. Pelvic fractures may be minimized by preoperative or intraoperative traction. Exclusion criteria include: 1. Age < 14 years; 2. 0pen pelvic fracture; 3. Having a skin infection in the incision location. 4. Surgical incision and investigation are indicated when vascular and nerve damage is present. 41 patients with pelvic fractures who satisfied the inclusion criteria were divided into two groups at random: the traditional surgery group had 20 patients, whereas the preoperative planning group had 21.
According to the patient's ante-posterior, inlet and outlet X-rays, and a preoperative thin CT scan (0.625 mm thickness), the fracture type was diagnosed. The surgical procedure was determined based on the type of fracture.
All of the patients were supine for the procedure, which was carried out by the same skilled surgeon. The physician determined and utilized standard intraoperative lateral, inlet, and outlet radiographs of the pelvis. Simultaneously, a skilled radiologist operates the same C-arm machine and adjusts it to seek the optimal X-ray image.
According to the standards of screw position published by Smith et al. [16], the screw position was divided into four grades: grade 0, no perforation; grade 1, perforation less than 2 mm; grade 2, perforation of 2–4 mm; grade 3, perforation > 4 mm.
Gender, age, fracture type, mechanism of injury, time of screw placement (from the insertion of the guidewire into the skin to the completion of the screw placement), time of radiation exposure during screw placement, and postoperative screw position were all recorded.
Procedure
Preoperative planning group
After admission, the patient underwent a routine plain pelvic CT (Light speed VCT, GE, America) scan, and CT images of 0.625 mm thickness were obtained. CT images were imported into Mimics software (Materialise, Belgium) to obtain the patient's pelvic standard lateral views, and inlet and outlet views (Fig. 1a, b, c). The screw diameter was set to 6.5 mm using the Multiplanar reconstruction (MPR) function in the program to simulate the screw; a screw track was built according to the patient's situation, with the screw at a safe distance from the front, back, above, and below the sacrum. The X-ray simulation capability was utilized to model the screw entry and exit points on the conventional sacral lateral image after the screw was set. At the same time, the screw trace was preserved in conventional sacral lateral, inlet, and outlet images. The nine stages were created by artificially dividing standard sacral lateral images, inlet images, and outlet images. Standard lateral radiographs of the sacrum divided the first sacral vertebra into nine grids of 3 × 3 (classification criteria: Three portions of the sacral 1 upper endplate, three parts of the lower endplate, three parts of the prevertebral cortex, three parts of the posterior vertebral cortex, and the corresponding bisection sites of the upper and lower parts, as well as the anterior and posterior parts, were connected; Lateral radiographs(L), Fig. 1d). The inlet image is separated into nine parts artificially: the vertex of bilateral lateral recess was used to draw a sagittal line forward, and the intersection of the anterior border of sacral 1 vertebral body was indicated. The square area encircled by four points was divided into nine regions. (Inlet radiographs(I), Fig. 1e), and the output image split the medial edge of the bilateral sacral foramina as the parallel tangent line of the middle sagittal line and the top edge of the bilateral sacroforamina as the parallel tangent line of the horizontal line into nine grids. (Outlet radiographs(O) Fig. 1f). On standard lateral views of the sacrum (Fig. 1g), screw entry areas were found, and needle points were marked on the inlet and outlet images in simulated radiography (Fig. 1h, i). According to preoperative planning, screw tracks were simulated on lateral, inlet, and outlet images.
The iliosacral screw trajectory was generated using the patient's preoperative CT three-dimensional model. The patient's body and the operating table were adjusted so that the patient's body was parallel to the floor at the center of the operating table. After disinfection, the c-arm angle was adjusted to obtain standard lateral and inlet and outlet radiographs of the sacrum. The ground was marked and the rotation angle of the c-arm was recorded. The guiding needle tip was adjusted according to the pre-planned screw insertion location on standard lateral radiographs of the sacrum. The guide needle was gently hammered into the bone using a bone hammer once it had been adjusted to the proper insertion site. At this stage, the inlet and outlet views, as well as the guidewire pointing at the inlet and outlet views, were changed under the preoperative planning. To prevent the guidewire from altering the track, the bone hammer was gradually hammered into the region according to this angle, and fluoroscopy was conducted again after the cortex was penetrated. After the needle was placed along the preoperative trajectory, standard lateral and inlet and outlet radiographs of the sacrum were obtained again. After measuring the required length of the screw with a needle tester, a screw (Synthes Gmbh, Switzerland) of proper length was inserted (Fig. 2).
Conventional surgery group
The patient lay supine on a fluoroscopy carbon fiber operating table while the same surgeon used a C-arm machine to execute standard screw placement. The guidewire (diameter: 2.5 mm) was first put in a safe screw placement region after obtaining standard lateral imaging of the sacrum. The guidewire was then carefully hammered into the bone with a bone hammer to prevent the position of the guidewire from being lost. Adjust the guide wire's orientation at the inlet and outlet views, then hammer into it in this direction after it's found in the osseous suitable safe path at the inlet and outlet views. Measure the guide wire's length and insert it in the proper length (Fig. 3).
Anterior–posterior pelvic radiographs, inlet and outlet radiographs, and a postoperative CT scan were taken three days after surgery to determine screw placement and fracture reduction. The quadriceps femoris muscle in both lower limbs was intensively trained on the second day after surgery. One week after a type B fracture, the patient was able to sit up in bed. 2 weeks after surgery: partial weight-bearing; 3 weeks after surgery: full weight-bearing Sit up in bed two weeks after a type C fracture operation; partial weight-bearing four weeks after surgery; full weight-bearing six weeks after surgery. Patients returned to the hospital 1.5, 3, 6, and 12 months following surgery for follow-up.
Statistics
Following data collection, t-test and Chi-square tests were performed to compare the traditional surgery group to the preoperative planning group in terms of screw placement time, radiation exposure time, and precision. For categorical data, descriptive statistics are reported as ratios, and for continuous variables, mean plus standard deviation. Fisher's exact test was used to generate p values whenever the anticipated numbers of cell entries were less than 5. SPSS statistics software version 22.0 (SPSS, Chicago, IL) was used for all statistical analyses. Statistical significance was defined as p-value < 0.05.