Improving outcomes after total hip arthroplasty: the impact of patient factors, surgical approach & implant design

Abstract

This thesis contributes to the evidence-base of the influence of patient factors, surgical approach and implant design on outcomes after total hip replacement (THA).

A systematic review (SR) shows that there is strong evidence for BMI, age, comorbidity, preoperative functioning and mental health as predictors of physical functioning. A predictive model based on data from this thesis emphasizes preoperative functioning, mental health and pain as predictors.

To treat hip fractures, the posterolateral (PLA) and direct lateral surgical approach (DLA) are the most commonly used. The PLA may cause more dislocations, but seems to result in less walking problems and abductor insufficiency than the DLA. All investigated surgical approaches for primary THA resulted in a significant improvement in patient reported outcome measures (PROMs). The anterior and posterolateral approaches provided greater improvement in physical function and pain, but clinical differences were small.

A multicenter randomized trial comparing two hip stems is described. No significant difference has been demonstrated between the Collum Femoris Preserving (CFP) and Zweymüller stem in physical function at 5 years or implant survival at 12 years, although CFP may be inferior in cup revisions. A SR suggests lower dislocation rates and revisions for dual mobility cups in THA, but high quality evidence is lacking. Therefore, we designed an RCT comparing dual mobility cups with unipolar cups in older patients. In addition to providing insights into the influence of patient, surgical and implant characteristics on outcome after (total) hip arthroplasty, this thesis provides suggestions for the design of future clinical trials.