Objective      To evaluate the bone cement distribution and biomechanical stability of self-designed bone cement injectable canulated pedicle screw (CICPS).       Methods      CICPS

DTPS

TM

and solid pedicle screws were implanted into osteoporotic bone models (density: 0.16 g/cm

3

n=7) according to the clinical standard procedure. Four different volumes of bone cement (1

2

3 and 5 ml) were used to reinforce CICPS and DTPS

TM

respectively

and the solid pedicle screws were used as control. X-ray and CT were applied to observe the bone cement distribution in different groups. Maximum axial pullout strength test was used to analyze the relationship between the bone cement volume and maximum axial pullout strength

and the biomechanical stabilities of CICPS

DTPS

TM

and solid pedicle screws were compared.       Results      X-ray showed that there was no bone cement rear leakage in all screws. Three-dimensional reconstruction of X-ray and CT showed bone cement well and widely distributed through the three side holes of the CICPS in bone models. Bone cement flowed out mainly through the proximal side hole of the DTPS

TM

but rarely through the distal side hole. The maximum axial pullout strength of each group was as follows: solid pedicle screws: (28.5±4.0) N; CICPS: 1 ml (140.3±15.9) N

2 ml (197.1±9.8) N

3 ml (215.4±10.7) N and 5 ml (237.0±23.6) N; and DTPS

TM

: 1 ml (114.3±17.7) N

2 ml (180.5±13.6) N

3 ml (207.2±30.0) N and 5 ml (291.3±25.1) N. The maximum axial pullout strength of the CICPS and DTPS

TM

after reinforced by bone cement was significantly greater than that of the control group

and the strength increased along with the increase of bone cement volume. When the volume of bone cement was 1

2 and 3 ml

the biomechanical stability of the CICPS was higher than that of the DTPS

TM

(P0.05). When the volume of bone cement was 5 ml

the biomechanical stability of the DTPS

TM

was higher than that of the CICPS (P0.05).       Conclusion      It is effective to enhance the biomechanical stability of CICPS by bone cement reinforcement in osteoporotic bone model. When the volume of bone cement for clinical treatm

ent was 1-3 ml

the CICPS is proved safer and more stable than other products.