PhD defence A. (Bart) ten Brinke

Dissertation in short:

Radiostereometric Analysis (RSA) is an accurate method to assess migration of orthopaedic implants. A relation between early migration and long-term implant loosening has been demonstrated in hip and knee arthroplasty. The aim of this thesis was to investigate the potential role of RSA in the upper extremity.   

In a systematic review we demonstrated that precision of RSA is high in shoulder and elbow arthroplasty, but low for the trapeziometacarpal (TMC) joint. In an experimental and clinical pilot study we demonstrated that precision of RSA in the TMC joint is high for translations but low for rotations.  

In a long-term study concerning the elbow we evaluated clinical outcomes and migration of an elbow implant up to fourteen years postoperatively. Short-term migrations did not differ between revised and non-revised implants. In a short-term RSA study analyzing the humeral  component in stemless shoulder arthroplasty we demonstrated continuous migration in 17% of the implants. These migration values raise concerns about implant safety and long-term follow-up is therefore essential.  

In conclusion, migration of implants in the upper extremity can be assessed with high precision, in particular in shoulder arthroplasty. We recommend routine evaluation of shoulder implants using RSA. Unlike the shoulder, concerns about the feasibility of RSA in the elbow and TMC joint have to do with the limited size of the surrounding bone. Before further RSA studies will be performed in these joints, we recommend to examine the feasibility of newly developed techniques as CT-based RSA.