Computational Modeling and Mechanical Testing of Calcaneus Fracture Plates: A Review.

This review article surveys all computational and experimental investigations that varied plate and/or screw variables to evaluate the mechanical effect on calcaneus (i.e., heel bone) fracture plates (CFPs). PubMed, Scopus, and Web of Science archives were examined for studies published on any date and in any language that (i) mechanically characterized the effect of changing plate and/or screw variables on CFP performance, rather than just comparing or augmenting CFPs with other types of implants and (ii) only analyzed calcaneus fractures, rather than other co-injuries of the ankle or foot. The 36 eligible studies evaluated various plate variables (i.e., geometry, hole type, number) and screw variables (i.e., geometry, number, distribution, angle), but not plate position or material. The studies reported engineering outcome metrics like (i) interfragmentary motion (0-11.24 mm; 0-1.20 deg), (ii) bone (2.6-502.6 MPa), plate (11.4-1084.0 MPa), or screw (19.7-524.5 MPa) stress, (iii) bone stress under the plate to evaluate "stress shielding" (0-50.0 MPa), (iv) the number of loading cycles to failure (1000-89,250 cycles), (v) overall stiffness (22-5108 N/mm), or (vi) failure strength (100-7867 N). This review also discusses future work for implant variables, bone variables, study methodologies, and clinical items, as well as recommending a particular CFP configuration for maximal mechanical stability. This review will help biomedical engineers and orthopedic surgeons to effectively design, analyze, or use CFPs.