Clinical Application Of 3D Printed Metal Pad In Acetabular Defect Reconstruction

Objective:In hip revision surgery,how to deal with complex acetabular defects is the most challenging problem in joint surgery.Residual bone mass in patients with complex acetabular defects is not sufficient to provide adequate initial stability.Traditional treatments have limitations in reconstructing the acetabulum and accurately matching.With the development of 3D printing technology,personalized prostheses and pads have brought new ideas for the treatment of complex acetabular defects.This study reviewed the short-term efficacy of 3D printing in the treatment of acetabular defects in joint surgery in our hospital,and analyzed the clinical application of 3D printing in complex acetabular defect hip revision surgery.Methods:From January 2013 to December 2017,the clinical data of 39 patients with 39 hips of Paprosky type III acetabular defect who underwent hip revision surgery in the Department of Joint Surgery,Second Hospital of Jilin University were collected.33 cases of 33 hips were completely followed up,there were 17 males and 16 females,with an average age of 62.6±11.3 years(range 30—83 years).The average duration from primary arthroplasty to revision arthroplasty is 8.5±6.0 years(range 0.5-25 years).There were 17 left hips and 16 right hips.According to the treatment method,the patients were divided into three groups,and the control group 1 was treated with a large acetabular prosthesis(Jumbo cup)combined with bone graft treatment.Control group 2 was treated with cages combined with bone grafting.The observation group is a patient who is treated with 3D printed metal pad.We compared and analyzed harris score,VAS score and the mean vertical position of hip center of rotation from the inter teardrop line.We evaluated the hip function recovery and acetabular reconstruction and evaluated the early clinical efficacy of the technique.Results:The average follow-up was 13.3 ± 7.6 months(range: 3-39 months).Functional evaluation: In the 3D printing pad group,the Harris score improved from 29.6±8.5 preoperatively to 86.4±4.2 postoperatively,the difference was statistically significant(P<0.05).VAS score changed from 8.0±0.7 preoperatively to 1.0±1.2 postoperatively,the difference was statistically significant(P<0.05).In the jumbo cup group,the Harris score improved from 38.3±12.4 preoperatively to 73.9±7.1 postoperatively,the difference was statistically significant(P<0.05).VAS score changed from 7.1±1.0 preoperatively to 1.5±1.2 postoperatively,the difference was statistically significant(P<0.05).In the cages group,the Harris score improved from 36.6±8.4 preoperatively to 74.4±6.8 postoperatively,the difference was statistically significant(P<0.05).VAS score changed from 7.6±0.9 preoperatively to 1.1±1.0 postoperatively,the difference was statistically significant(P<0.05).There were no significant differences in preoperative Harris score and VAS score between the 3 groups(P>0.05).In the postoperative harris score,the 3D print pad group was higher than the other two groups(P<0.05).There was no significant difference between the Jumbo cup group and the cages group(P>0.05).There were no significant differences in postoperative VAS score between the 3 groups(P>0.05).Image evaluation: In the 3 groups,the X-ray showed that no cases suffered aseptic loosening and migration.In the 3D printing pad group,The mean distance of the HCOR to the inter-teardrop line changed from 39.8±8.0mm preoperatively to 14.6±6.4mm postoperatively,the difference was statistically significant(P<0.05).The mean distance of the HCOR to the inter-teardrop line was 14.8±6.1mm at the last follow-up,There was no significant difference between the last follow-up and postoperative(P>0.05).In the jumbo cup group,The mean distance of the HCOR to the inter-teardrop line changed from 37.4±3.2mm preoperatively to 33.9±4.2mm postoperatively,the difference was statistically significant(P<0.05).The mean distance of the HCOR to the inter-teardrop line was 34.2±4.1mm at the last follow-up,There was no significant difference between the last follow-up and postoperative(P>0.05).In the cages group,The mean distance of the HCOR to the inter-teardrop line changed from 40.1±9.5mm preoperatively to 21.1±7.9mm postoperatively,the difference was statistically significant(P<0.05).The mean distance of the HCOR to the inter-teardrop line was 21.2±7.8mm at the last follow-up,There was no significant difference between the last follow-up and postoperative(P>0.05).There were no significant differences in preoperative that the mean distance of the HCOR to the inter-teardrop line score between the 3 groups(P>0.05).Among the 3 groups,the 3D print pad group had the largest drop rate of HCOR,followed by the cages group,and the Jumbo cup group had the smallest HCOR drop distance.The comparison between the three groups was statistically significant(P<0.05).Conclusion:1.For Paprosky III complex bone defects,hip joint function and hip rotation center recovery in patients treated with Jumbo cup combined with bone graft,cages combined with bone graft and 3D printed pad can be compared with preoperative Significantly improved,can relieve pain and improve the quality of life of patients.2.Compared with other treatment methods,3D printing pad treatment can better restore the hip function of the patient and reconstruct the anatomical position of the hip rotation center,maximize the preservation of residual bone mass in the acetabulum,improve patient satisfaction and provide protection for the long-term survival rate of the prosthesis.