Three-dimensional printing for fabricating individualized endplate matching cervical cage

Objective To explore the feasibility of fabricating individualized cervical cage by three-dimensional printing and to verify the endplate matching of cage.Methods Ten fresh adult cervical specimens(5males and 5females,C1-C7)were subjected to CT-scan.The original Dicom data were fed into the Mimics software to create the fifth and sixth cervical vertebra and disc model,which was used to prepare individualized cervical cage using three-dimensional printing technique.All the specimens received anterior cervical discectomy and fusion in C5/6 disc,and CT-scan was taken postoperatively to access the endplate matching of cage.The matching degree was accessed at 36 points in each cage;excellent matching was defined as the distance between endplate and cage being less than 1mm,good as the distance being greater than or equal to 1mm while less than 2mm,and poor as the distance being greater than or equal to 2mm.Results Gross observation found that the cage well fit the veterbral disc,with satisfactory stability,with no cage being too large for implanting into the veterbral disc or cage dropout.Six(60%)specimens had excellent matching on all the 36 points.Three specimens had 14(3.89%)points matched good,including one with 6points and two with 4points each;the last specimen had 3(0.83%)points matched poor.A total of 343points(95.28%)had excellent matching in the present study.Conclusion Mimics software can well present the anatomical structures of cervical vertebral body and intervertebral disc,enabling individualized design of cervical cage.Three-dimensional printing can achieve rapid prototyping of individualized cage,which can well match the host endplate.