Development of an injectable and bone-inducing cage for transforaminal lumbar interbody fusion under Xtube system and its anatomic study

English Keywords:Xtube  Interbody fuaion cage  Injectable artificial bone  Transforaminal lumbar interbody fusion

English Abstract:

  【Abstract】 Objective：To investigate relative anatomic issues of a new injectable and bone-inducing cage for miniamlly invasive transforaminal interbody fusion.Method：A minimally invasive cage together with injectable artificial bone was developed for TLIF，its size was determined by anatomic measurements.40 Chinese human cadver lumbar specimens were used to measure the idea length of cage placed obliquely as well as the ideal oblique angle（α） across middle-line at L3/4、L4/5 and L5/S1 respectively，and the introversion angle for instrument placement under the Xtube system（μ） were recorded either.Result：The α angle was 23.9°±3.8°（21.3°-28.2°），25.8°±3.1°（22.2°-29.2°） and 28.8°±3.8°（26.9°-33.6°） respectively for L3/4，L4/5 and L5/S1.The ideal lengths for the cages under correspondence α angle was 28.7±4.4mm（26.8-31.2mm），29.3±3.8mm（27.3-31.8mm） and 30.4±4.6mm（28.6-30.8mm） for L3/4，L4/5 and L5/S1 respectively.The μ angle for Xtubes was 22.3°±2.5°（18.3°-27.5°）.Conclusion：When performing minimaly invasive transforminal interbody fusion using single cage，larger introversion angle in L5/S1 than in L3/4 and L4/5 is recommended，and theoretically larger the length of cage in L4/5 and L5/S1 is larger than in L3/4.