Finite Element Study On Arthroscopic Anchor Design Aspects

This research aims to study arthroscopic anchors design parameters. Prototypes were manufactured by new parameters values. The the performance of the prototypes was also tested.

Five 3D arthroscopic anchor models were created to evaluate the role of some design aspects. Thread type, pitch and tip angle were tested as variable parameters. These models were produced on engineering CAD software then imported into ANSYS for finite element analysis. A tensile load of 300 N was applied to each model while the simplified bone base was fixed-in-place as a boundary condition. The finite element results were compared with prototypes tensile testing.

The finite element analyses showed stresses within physiological limits on the bone with all tested models. Thread type and pitch affected stresses on bone and anchor body. From stress point of view, two critical zones appeared on anchor body, anchor cortical bone connection and eyelet zone, while thread geometry (depth) affect the cortical bone response only. Laboratory tests matched finite element results and literature.

Increasing thread pitch of arthroscopic anchors decreases stress on the bone, while increases stress on anchor body. Arthroscopic anchors thread type has a negligible effect on bone, while it reduces stresses on anchor body if it placed more material around eyelet in internal drive mechanism and suture eyelet type of anchors. Anchor tip angle has a negligible effect on bone and anchor body.