Evaluation of three-dimensional printing for internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach: a preliminary report

Abstract

Objective: The aim of this study is to evaluate the efficacy and feasibility of three-dimensional printing (3D printing) assisted internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach.

Methods: A total of 38 patients with unstable pelvic fractures were analyzed retrospectively from August 2012 to February 2014. All cases were treated operatively with internal fixation assisted by three-dimensional printing from minimal invasive para-rectus abdominis approach. Both preoperative CT and three-dimensional reconstruction were performed. Pelvic model was created by 3D printing. Data including the best entry points, plate position and direction and length of screw were obtained from simulated operation based on 3D printing pelvic model. The diaplasis and internal fixation were performed by minimal invasive para-rectus abdominis approach according to the optimized dada in real surgical procedure. Matta and Majeed score were used to evaluate currative effects after operation.

Results: According to the Matta standard, the outcome of the diaplasis achieved 97.37% with excellent and good. Majeed assessment showed 94.4% with excellent and good. The imageological examination showed consistency of internal fixation and simulated operation. The mean operation time was 110 minutes, mean intraoperative blood loss 320 ml, and mean incision length 6.5 cm. All patients have achieved clinical healing, with mean healing time of 8 weeks.

Conclusion: Three-dimensional printing assisted internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach is feasible and effective. This method has the advantages of trauma minimally, bleeding less, healing rapidly and satisfactory reduction, and worthwhile for spreading in clinical practice.

Keywords: 3D printing; internal fixation; minimally invasive; para-rectus abdominis approach; pelvic fracture.

Figure 1

Virtual implantation of internal fixiation. A 44-year-old woman, pelvic fractures caused by high falling injury. Tile’s classification is type B. Preoperative digital virtual diaplasis and design of plate and screw are showed.

Figure 2

Simulated operation by 3D printed pelvic model. Bending plates on the reduction model find its design position; Fixing plates on the reduction models. The model came from the patient showed in Figure 1.

Figure 3

The operative process of pelvic fracture. The case in Figure 3 is the same patient as showed in Figures 1 and 2. A. Incision mark; B. Expose aponeurosis of obliquus externus abdominis and rectus abdominis anterior sheath; C. Expose the iliac crest; D. Place the plate in iliac crest; E. Exposed greater sciatic notch and iliopubic eminence, and placed the plate; F. Exposed superior ramus of pubis and placed the plate.

Figure 4

Imageological comparison between preoperation and postoperation. Preoperative three-dimensional CT scan (A) showed fracture displacement and postoperative X-ray examination (B) showed good reduction of the fracture for the case in Figure 1.