Testing of Novel Total Elbow Prostheses Using Active Motion Experimental Setup

Abstract

Purpose: The goal of this study was to test a novel uncemented and unconstrained total elbow arthroplasty (Kaufmann total elbow) design that is stabilized through a ligament reconstruction.

Methods: We quantified the implant stability after 25,000 cycles, which represents the time between implantation and when ligament and bone healing has occurred. We used an active motion experimental setup that applies tendon loads via pneumatic cylinders and reproduces the forearm-originating dynamic stabilizers of the elbow. The novel total elbow arthroplasty was actuated for 5,000 full flexion-extension cycles at 5 different shoulder positions. Four Sawbones and 4 cadaver elbows were employed. Angular laxity and implant stability were recorded prior to testing and after each 5,000-loading cycle.

Results: Four Sawbones and 4 cadaver elbows were implanted with the uncemented total elbow arthroplasty and did not demonstrate fixation failure or substantial laxity after 25,000 cycles of loading imparted at different shoulder positions.

Conclusions: Our findings demonstrate that the Kaufmann total elbow replacement implanted into cadaver and Sawbones specimens did not exhibit fixation failure or excessive laxity after 25,000 cycles.

Clinical relevance: An uncemented, nonmechanically linked total elbow arthroplasty that gains component fixation using intramedullary screws and employs a ligament reconstruction to stabilize the elbow has the potential to be a valuable management option, particularly in younger patients.

Keywords: Active; arthroplasty; cadaver; testing; uncemented.