In vitro evaluation of free-form biodegradable bone plates for fixation of distal femoral physeal fractures in dogs.
OBJECTIVE
To design and manufacture free-form biodegradable polycaprolactone (PCL) bone plates and to compare mechanical properties of femoral constructs with a distal physeal fracture repaired by use of 5 stabilization methods.


METHODS
40 canine femoral replicas created by use of additive manufacturing and rapid tooling.


METHODS
Surgery duration, mediolateral and craniocaudal bending stiffness, and torsional stiffness of femoral physeal fracture repair constructs made by use of 5 stabilization methods were assessed. The implants included 2 Kirschner wires inserted medially and 2 inserted laterally (4KW), a commercial stainless steel plate (CSP), a custom free-form titanium plate (CTP), thin (2-mm-thick) biodegradable PCL plates (TNP) placed medially and laterally, and thick (4-mm-thick) PCL plates (TKP) placed medially and laterally.


RESULTS
Surgical placement of 4KW was more rapid than placement of other implants The mean caudal cantilever bending stiffness of CTP and CSP constructs was greater than that for TNP TKP and 4KW constructs, and the mean caudal cantilever bending stiffness of TNP and TKP constructs was greater than that for 4KW constructs. The mean lateral cantilever bending stiffness of TKP constructs was greater than that for 4KW constructs. Differences among construct types were not significant in yield strength, ultimate strength, yield torque, and ultimate torque.


CONCLUSIONS
The mechanical properties of fracture repair constructs made from free-form PCL biodegradable plates compared favorably with those of constructs made from Kirschner wires. The impact of PCL plates on musculoskeletal soft tissues, bone healing, and bone growth should be evaluated before clinical use.
Department of Clinical Sciences, College of Veterinary Medicine, College of Engineering, North Carolina State University, Raleigh, NC 27606, USA. denis_marcellin@ncsu.edu
Denis J
DJ
Marcellin-Little
Brian J
BJ
Sutherland
Ola L A
OL
Harrysson
Erica S
ES
Lee
D020341:Absorbable Implants / Q000662:veterinary*; D000818:Animals; D001860:Bone Plates / Q000662:veterinary*; D001864:Bone Wires / Q000662:veterinary; D017076:Computer-Aided Design; D004283:Dog Diseases / Q000601:surgery*; D004285:Dogs; D004867:Equipment Design; D005264:Femoral Fractures / Q000601:surgery / Q000662:veterinary*; D005269:Femur / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000662:veterinary