External fixators (Hoffmann II®, Wuhan Constant Science and Technology Ltd. Hubei, China), steel plate and screws (Beijing BEST BIO Technical Co., Ltd. Beijing, China), K-wire (Suzhou Gemmed Medical Instrument Co., Ltd. Jiangsu, China), vacuum sealing drainage devices (VSD) (Wuhan VSD Medical Science and Technology Co. Ltd. Hubei, China).
The inclusion criteria for this study is as follow: (1) open fracture of distal tibia and fibula, fracture type: AO-42; (2) surgical methods: simple external fixation, external fixation combined with plate-screw osteosynthesis, external fixation combined with K-wire intramedullary fixation; (3) regular follow-up. Exclusion criteria: (1) ankle joint surface damaged severely, normal correspondence congruence and joint space can’t be restored through fixation; (2) associated with serious hypertension, heart disease and other serious diseases, reduced operative-tolerance; (3)associated with brain and spinal nerve functional impairment, severely affected the function of the lower limbs; (4)previous history of severe degenerative arthritis, rheumatoid arthritis, cerebral infarction, and dyskinesia in the lower extremities.
From January 2017 to July 2019, 91 cases of open fractures of distal tibia and fibula were enrolled into this study, among which 35 patients were treated by simple external fixation (group A, n=35), 30 patients were treated by external fixation combined with plate-screw osteosynthesis (group B, n=30), and 26 patients were treated by external fixation combined with K-wire(2.0-3.0mm) intramedullary fixation (group C, n=26). There was no significant difference in gender, age, cause of injury, Gustilo classification and AO classification among the three groups (P > 0.05) (Table 1).
All patients were given emergency debridement. After successful anesthesia, the patient was put in the supine position, plenty of 0.9% saline, hydrogen peroxide and iodophor were used to flushing the wound, disposable negative pressure washing gun could be choose if the wound was deep and polluted seriously. Pneumatic tourniquets are available for operations about the root of patient’s thigh and the lower limb may be prepared and draped before the tourniquet is applied. If necessary, the incision should be prolonged along the wound location to remove contaminated tissue and skin edges, inactivated or suspected inactivated tissue. Investigate the wound carefully and find out whether the fracture end is exposed and if there were vascular and nerve injuries, marked the injured vessels and nerves with silk thread, and reconstructed them after the fracture was fixed. The patients injured in 8 hours were fixated according to the general condition after debridement. For patients who were injured over 8 hours, calcaneal traction was given temporarily, and fracture fixation should be completed within 7 days.
Three groups of patients were treated respectively with simple external fixator (Group A), external fixator combined with plate-screw osteosynthesis (Group B), external fixator combined with K-wire intramedullary fixation (Group C) for fracture reduction and fixation.
In group A, closed reduction was performed first, fracture ends were antagonized traction and restored with the help of C-arm. If the reduction is not ideal, cut a 3-4 cm incision for exposing fracture ends of tibia and cleaning soft tissue and blood clots embedded in the fracture site. Then the fracture end could be reduced by traction and temporary fixation assisted with bone-holder or K-wire. After the initial reduction of the fracture, inserted screws into the proximal and distal segments of tibia fracture end, the calcaneus or the first metatarsal bone depending on the location of the fracture, installed the fixation clips for each screw and connected them with a biplanar external fixators. The C-arm fluoroscopy was used to examine and adjust the reduction to be in good alignment, then the screw of the fixator was fastened completely. Fracture ends of fibula were not fixed (Figure 2).
For patients in group B, fracture ends of tibia were fixed with external fixator first in the same way with group A. Then an incision about 10 cm was made centered on the fracture ends of fibula, cut the skin and subcutaneous tissue layer by layer, peeled off the periosteum locally, exposed the fracture ends of fibula, checked the fracture situation, cleaned up the fracture ends and fixed the fracture reduction with bone-holder temporarily, then fixed the fractures with an appropriate length locked plate. The anterior-posterior and lateral views should both be checked and rotary restoration should be confirmed. Once functional reduction is accomplished, the locking screws are driven in (Figure 3).
External fixation combined with K-wire intramedullary fixation was conducted in group C. Firstly, fracture ends of fibula were fixed intramedullary with a K-wire. A 0.5cm incision was made 2.0 cm above the tip of fibula, and a K-wire of 2.0-3.0 mm diameter was inserted retrograde into the fibular marrow cavity from the bottom to the top. If necessary, a hammer could be used to tap the tail of the Kirschner needle to help insert the needle. During the process of inserting the needle, the K-wire should be parallel to the long axis of the tibia, the multi-segment fractures of fibula were restored in turn with the help of assistant. Adjust the K-wire under the C-arm examination until the fracture of the fibula was in good alignment. The tip of the K-wire should be 10.0cm more passed through the proximal end of the fibula fracture so as to achieve an effective fixation. The tail of the needle is reflexed outside the skin for easy daily disinfection and care. After fibula fracture was fixed, external fixator was used to fix tibia fracture in the same way with group A (Figure 4).
Treatment of complications
After the fracture was fixed, washing the wound with plenty of saline, then reconstructed the injured blood vessels and nerve. Made primary suture for Gustilo I and Gustilo II patients with less pollution and soft tissue contusion. The patients of type III A, type III B and type III C were treated with partial tension reduction suture because of the large wound and serious pollution. Covered the wound with VSD membranes and connected to a negative pressure drainage tube. For patients with large area of skin and soft tissue defects, Shengjigao (Tianjin Hospital, Tianjin, China) was applied to the wound after 2 weeks from operation to promote rehabilitation. Flap transfer or skin grafting should be performed in the second stage after the improvement of the soft tissue condition of the wound.
Postoperative treatment and follow-up
All the patients were given routine antibiotics in the perioperative period to prevent infection, and postoperative analgesia, improving circulation, bone strengthening, prevention of thrombosis and other symptomatic supportive treatment. The wound was treated by dressing change or replacement of VSD regularly and the tail of the K-wire was disinfected with iodophor every day to prevent the infection of wound and pin tract. The patient's contact information was registered at the time of discharge, and the patient was reviewed periodically. Fracture healing of the tibial and fibula has been observed with X-ray diagnostic techniques. After 8~12 weeks of follow-up, the K-wire was removed according to the status of external fixation and fracture healing. Later, the patients were followed-up every 3 months and the external fixator was removed when the clinical healing of the fracture was confirmed. During the subsequent visit, professional rehabilitation training guidance should be given according to the different stages of the patients' recovery. The patient's limb function was evaluated at the last follow-up.
Data collection and analysis
The operation time, intraoperative blood loss, surgical and implants costs, fracture healing time, postoperative complications and AOFAS scores at the last follow-up were recorded in the three groups. Fracture healing was assessed by X-ray examination and union was defined as dense callus bridging at least three of four cortices on positive and lateral X-ray examination. Delayed union was defined as radiographic union after >8 months. Nonunion was defined as lack of any healing within 12 months. Data analysis was performed by SPSS software, version 25.0 (SPSS, Inc., Chicago, IL, USA). Continuous variables were expressed as mean ± SD and differences in continuous variables among groups were examined using analysis of variance (ANOVA) and repeated measure of ANOVA. Pearson’s chi-squared analysis (χ2 test) and Fisher’s exact test were used for categorical variables. The level of significance was set at P<0.05.