1.1 Inclusion and exclusion criteria
Inclusion criteria: 1. Patients with simple tibial shaft fractures (Type A, B and C1, C2 according to the AO classification); 2. No open wound discovered around the fracture area; 3. No significant ipsilateral displacement that affecting reduction of ankle and knee fractures; 4. Normal cardiopulmonary function and stable hemodynamics; 5. No obvious osteoporosis;
Exclusion criteria: 1. Patients with complex, comminuted or multi-segment tibial shaft fracture; 2. Complicated with open injury involved the operation area; 3. Ipsilateral knee and ankle joint injury and/or fracture displacement that affecting the operation method; 4. Patients with refractory severe hypertension (>180/110mmHg); patients with refractory blood sugar> 13.9mmol/L; patients with severe cardiopulmonary, liver and kidney insufficiency; patients with systemic diseases and immunodeficiency; patients with severe malnutrition or conditions unsuitable for surgery; patients with infection, bacteremia, and/or sepsis; other conditions which might render the patient intolerable for surgery; 5. patients with severe osteoporosis that affect the stability of intramedullary nail fixation; 6. patients who refused to participate the study; 7. Patients with severe mental illness or other cognitive disorders that might seriously affect postoperative functional evaluation; 8. Patients with pathological fractures;
1.2 Surgical procedures
All patients were operated on by the same experienced orthopedic and trauma surgeon. To prevent biases, all records were examined by two independent orthopedic surgeons who had no relation with the patient‟s treatment.
All patients were in the supine position and received spinal anesthesia. All intramedullary nails were non-reamed locking tibial interlocking intramedullary nail system (CanTN) provided by CANWELL.
In this study, all surgeries used infrapatellar approach. Some other studies[9, 10] might argue that the suprapatellar approach was a better approach but this study was not powered to examine the difference between different approaches.
The observation group (small incision reduction intramedullary nail fixation method): Centered by the end of the fracture, a small incision, usually 3 cm, was made with limited stripping of the periosteum before reducing the fracture end and temporarily fixing with bone clamp. Another longitudinal incision about 5cm above the tibial tubercle was carried out and the patellar ligament was split longitudinally to expose the "slope" of the tibial plateau. The medial side of the intercondylar crest of the tibial plateau was used as the entry point, and the platform was opened to the medullary cavity with a triangular pyramidal. Then the guide pin was inserted into the medullary cavity, followed by the selected intramedullary nail along the guide pin under C-arm fluoroscopy. After inserting the intramedullary nail, the temporarily fixed bone clamp was removed and the remote locking nail was installed followed by 2 suitable locking nails through the sleeve of the remote sight. Draw with the intramedullary nail backwards, and appropriately pressurize the fracture area. Insert 2 or 3 proximal locking nails through the sleeve of the proximal sight and remove the bracket and screw in the tail cap before the completion of the surgery.
The control group (closed reduction intramedullary nail fixation ): The closed reduction operation was used to reduce the fracture end, and the intramedullary nail was inserted after C-arm fluoroscopy identified the ideal position of the fracture end. The rest of the operation was carried out the same as the observation group.
1.3 Postoperative management
One day after the operation, antibiotics was given to prevent infection as well as other supportive treatments to relieve pain and other symptoms. On the second day after the operation, active flexion and extension exercises of knee joint, ankle joint and toe were performed in bed. After clinical and X-ray examinations showing clinical healing of the fracture, crutches can be gradually abandoned. Series of imaging were regularly taken to monitor the fracture healing process.
1.4 Observation indicators:
The operation time, blood loss and intraoperative complications (such as whether there is blood vessel or nerve damage) were documented. Patient was followed up at 2 weeks, 1 month, 3month and 6 months after the operation by either on-site or telephone follow-up. At two weeks and one month after the operation, the local incision healing of the patients was evaluated as well as the presence or absence of postoperative incision infection. The fracture healing and the function of the affected limb were observed at 1 month, 3month and 6 months after the operation (according to the Johner-Wruhs scoring standard and was graded into four levels: excellent, good, moderate, and poor).
1.5 Statistical methods:
All data was processed by statistical software SPSS12.0. The comparison between groups was examined by t test and χ2 test. P<0.05 indicated that the difference was statistically significant.
1.6 Safety indicators:
The two surgical methods applied in the study were verified for safety and the surgical technology was mature. In the process of closed reduction of the fracture end, the posterior tibial blood vessels and nerves might be damaged when the bone clamp was applied, but the incidence was extremely low. In this experiment, 3 patients with vascular and nerve damage were selected for safety indicators. If the adverse event exceeded the predetermined index, the experiment would be immediately terminated.
This study complies with relevant ethical standards and was approved by the hospital ethics committee.