Investigational growth factors utilized in animal models of spinal fusion: Systematic review

Table 3 Demographic characteristics for all included studies

Animal model	Studies (n)
Dog	1[32]
Rat	8[33,36,38,47-49,51,56]
Rabbit	7[34,35,37,40,42,52,54]
Macaque	1[20]
Sheep	7[41,43-45,50,53,55]
Baboon	1[39]
Goat	1[46]
Spinal levels fused
C3 – C4	4[43-46]
L1 – L2	1[32]
L2 – L3	1[55]
L3 – L4	3[20,50,56]
L4 – L5	12[32,35,36,38,39,41,47-49,51,54,55]
L3 – L5	2[33,53]
L5 – L6	7[20,34,37,40,42,50,52]
L6 – L7	1[35]
Spinal region
Cervical	4[43-46]
Lumbar	22[20,32-42,47-56]
Biomechanical location
Mobile segments	11[20,32,33,43-46,50,53,55,56]
Junctional segments	21[20,32-42,47-55]
Number of levels fused
1-Level fusion	19[34,36-49,51,52,54,56]
Two separate 1-level fusions	5[20,32,35,50,55]
2-Level fusion	2[33,53]
Surgical approach
Anterior	8[20,43-46,50,53,55]
Posterior	18[32-42,47-49,51,52,54,56]