Evaluation of 3D-printed patient-specific guides to facilitate fluoroscopic-assisted Kirschner wire stabilization of simulated capital physeal fractures in 3D-printed dog femur models.

Objective: To compare the efficiency and accuracy of freehand and three-dimensionally printed (3DP) guide-facilitated fluoroscopic-assisted Kirschner wire placement in the femoral capitis performed by novice and experienced surgeons.

Sample population: 3DP models of five skeletally immature dog femurs were replicated.

Methods: Virtual surgical planning was done to position three parallel, virtual Kirschner wires inserted from the lateral subtrochanteric surface of the femur, coursing proximomedially through the femoral neck to engage the central capitis without penetrating the subchondral bone. Patient-specific guides were designed and 3DP to facilitate optimal Kirschner wire placement in each femoral model. Four faculty surgeons and four surgery residents performed freehand fluoroscopic-assisted wire placement in the femoral models. Wire placement was repeated ≥1 month later using the 3DP guides. Surgical time, number of times wires were redirected, number of fluoroscopy images acquired and Likert scores from the participants were recorded. Post-procedural CTs of the femur models were used to assess wire placement by 3D analysis.

Results: The number of fluoroscopy images was greater (p < .001) and procedure time was longer (p < .001) for freehand applications, while Likert scores were greater (p < .001) for 3DP-guide applications. Wire placement was more accurate with 3DP guides. Subchondral bone penetration occurred more frequently during freehand applications (p < .01).

Conclusion: 3DP patient-specific guides resulted in faster, simpler, and more accurate Kirschner wire placement than freehand placement for both novice and experienced surgeons. Further cadaveric and clinical studies are warranted to evaluate the utility of 3DP patient-specific guides to facilitate minimally invasive fluoroscopic-assisted femoral capital physeal fracture stabilization in dogs.