Finite Element Analysis of Hollow-stemmed Shoulder Implants in Different Bone Qualities Derived from a Statistical Shape and Density Model
Abstract
The incidence of total shoulder arthroplasty procedures (TSA) to treat osteoarthritis has experienced the most rapid growth among all human joint replacements. However, stress shielding of proximal bone following its reconstruction is a complication of TSA triggering unfavorable adaptive bone remodeling, especially for osteoporotic patients.
A better understanding of how the shape and density of the shoulder vary among members of a population can help design more effective population-based orthopedic implants. Therefore, finite element models representing healthy, osteopenic, and osteoporotic bone qualities in a population were developed using our statistical shape and density model. Bones were reconstructed with hollow- and solid-stemmed implants and resulting changes in bone stresses were calculated. We concluded that the use of more compliant stems, such as hollow stems, could marginally mitigate the effect of stress shielding at the proximal humerus. Further increasing the compliance of stems by making them porous could improve bone-implant mechanics.