[Digital study on proximal clavicle anatomical plate based on 3D printing technology].

OBJECTIVE: To explore feasibility of 3D metal printing technology combined with virtual design proximal clavicle anatomical plate. METHODS: A 52-year-old male healthy volunteer was retrospectively selected to design proximal clavicle anatomical plate system by using Mimics15.01,NX12.0 and other software. STL data were input into 3D printer to print 1:1 clavicle model and proximal clavicle anatomical plate. The fit of the plate was tested in vitro and the accuracy of screw position was evaluated by imaging. Printing time of model,nail path design and fabrication time of the anatomical plate at proximal clavicle were recorded. RESULTS: The 3D metal printing proximal clavicle anatomical plate fitted well to clavicle model,orientation of proximal clavicle locking screw was accurate,and X-ray and CT scan showed the screw position was good. Printing time of model,the time of nail path design,and the time of making anatomical plate of proximal clavicle were 120,15 and 300 min respectively. CONCLUSION: The proximal clavicular anatomical plate system based on 3D metal printing technology could achieve good lamination of proximal clavicular fracture plate and precise screw placement,providing a new and accurate surgical method for the treatment of the proximal clavicular fracture.

Preoperative simulated surgery on 3D model assists osteotomy feasibility verification and surgical guidance for patients with cubitus valgus/varus deformity: a retrospective observational study.

BACKGROUND: As the common delayed complication of supracondylar fractures in children, cubitus valgus/varus deformity might lead to pain and loss of motion of the elbow. The current corrective treatment might not be accurate enough and even contribute to postoperative deformity. This study retrospectively analyzed the clinical value of preoperative simulated surgery on 3D model-assisted osteotomy feasibility verification and surgical guidance for cubitus valgus/varus deformity. METHODS: Seventeen patients were selected from October 2016 to November 2019. Deformities were analyzed from imaging data and 3D models and corrected after the simulated operations. The radiographic evaluation comprised osseous union, carrying angle, and anteversion angle of the distal humerus. The clinical evaluation was performed according to the Hospital for Special Surgery (HSS) scoring system. RESULTS: All patients underwent the operation successfully and had no postoperative deformity. The carrying angle was significantly improved postoperatively (P < 0.001). The anteversion angle of the distal humerus did not change significantly (P > 0.05). The HSS score rose after surgery (P < 0.001). The function of the elbow joint was excellent in seven cases and good in ten cases. CONCLUSION: Simulated surgery on 3D model plays an important role in osteotomy plan and surgical guidance, contributing to good surgical efficacy.

[Meta-analysis of direct anterior approach and other approaches for hemiarthroplasty in elderly patients with femoral neck fracture].

OBJECTIVE: To systematically evaluate the clinical efficacy of high-quality direct anterior approach (DAA) and other approaches for the treatment of elderly patients with femoral neck fracture. METHODS: Literatures published in English or Chinese about the direct anterior approach and other approaches for hemiarthroplasty in femoral neck fracture were searched on Cochrane Library, PubMed, EMBASE, Web of science, Wanfang, CNKI databases from their establishment to May 2019. According to the inclusion and exclusion criteria, two researchers independently screened the literatures, and extracted the data. The quality of RCT were evaluated by Cochrane Risk of Bias Assessment Tool, and non-RCT were evaluated by the NOS scale. Meta-analysis was performed using the RevMan 5.3 software. RESULTS: A total of 9 articles were included with 901 cases, in which 429 cases used DAA, and 472 used other approaches. DAA had a significantly lower dislocation rate compared to subgroup of posterior and posterolateral approach [OR=0.19, 95%CI (0.06, 0.61), P=0.005]. No significant differences were found between DAA group and subgroup of direct lateral and anterolateral approach[OR=1.08, 95%CI(0.20, 5.76), P=0.93]. Also there were no relevant differences between the DAA group and control in infection rate[OR=1.07, 95%CI(0.47, 2.43), P=0.88], perioperative fracture rate[OR=0.95, 95%CI(0.36, 2.50), P=0.92], re operation rate[OR=0.76, 95%CI(0.30, 1.89), P=0.55], overall complication rate [OR=0.88, 95%CI (0.63, 1.22), P=0.44], mortality [OR=1.33, 95%CI (0.84, 2.11), P=0.23], operative time[MD=1.43, 95%CI(-5.85, 8.71), P=0.70]. CONCLUSION: The current evidenceindicates that the DAA was associated with a significantly lower dislocation rate compared to posterior capsular approaches for hemiarthroplasty. There was no significant difference in dislocation rate with the lateral and anterolateral approach.