The prospective randomized study was presented in our medical center for the patients who diagnosed with tibial shaft fracture from July 2013 to December 2018. The study was approved by the Ethics Committee of the Affiliated Hospital of Medical College of Ningbo University, and written informed consent was obtained from each patient. all methods were performed in accordance with relevant guidelines and regulations.
Inclusion criteria:(1) closed tibial shaft fracture, (2) adult patients (older than 18 year), (3) treatment with Intramedullary nailing. Exclusion criteria:(1) open fracture, (2) vascular nerve injury,(3)associated intra-articular fracture of tibia, (4) pathological skeletal disease, (5) serious underlying diseases, (6) history of hormone use. After the patients were enrolled in this research, type of treatment was randomized by computer allocation. Each patient received a randomized numbered opaque envelops. The patients were divided into distraction support group (DS) and control group. All operations were performed by the same surgical team. An Angle greater than 5 degrees indicates malalignment.
Description of the device
As with the previous report12, the distraction support is a triangular stereoscopic bracket which contains femoral tray, tibial tray and base.(Fig. 1.) In the unfold station, keen joint support locates between femoral tray and tibial tray on the top of the triangle. Anterior nut is in the middle of tibial tray, which adjusts traction power and length during the surgery. Foot support is a square pedal in the distal of tibial tray. The posterior nut in the femoral tray is similar with the anterior one. The rang of knee flexion is depended on the choice of groove in the base. The pivot allows femoral tray, tibial tray and base to be folded in the same plane which facilitates antisepsis and storage.
Surgical treatment
Under adequate anaesthesia, the patient was positioned supine on a radiolucent fracture table. The distraction support was positioned beneath the operative limb. A sterile drape was placed on the keen joint support, which creating the barrier between the popliteal fossa and support. A sterile ankle strap was used to secure the ankle to tibial tray. The appropriate knee flexion was achieved by matching the suitable groove in the base. Simultaneously regulating the anterior nut on each side of tibial tray, persistently traction was applied to the fracture. The reduction was confirmed by fluoroscopy(Fig. 2). In conventional group, reduction was achieved by sustained traction from two assistants. All surgery adopt the same protocol of the transtendinous approach. 3.2 mm tibial guide wire was drilled into medullary space after lengthening incisal opening in the proximal tibia. Reaming was adopted when guide wire arrived the distal medullary space. The surgeon reamed 1 mm larger than the chosen nail’s diameter. Then, an appropriate intramedullary mail was inserted, which was confirmed by fluoroscopy. With oriented pin, Locking screws were fixed through stab incisions, both proximally and distally. Lastly, The distraction support was then removed. The incision was closed in a layered manner.
First-generation cephalosporin was administered to each patient pre-operatively and 24 hours postoperatively. Exercise was encouraged after operation immediately and weight-bearing walk was allowed after 4–6 weeks. The follow up was appointed at 1,3,6,9 and 12 months postoperatively.
Statistics
Statistical analysis was performed by SPSS software package (version 19). Shapiro-Wilk tests was used to assess normality and F test was adopted to measure variance homogeneity. Continuous variables are presented as mean ± standard deviations and compared via independent samples t-tests. Skewed variables are given as median and compared via Wilcoxon signed-rank tests. P < 0.05 indicated statistics significance.