RADIOLOGICAL EVALUATION OF THE INTERFACES AFTER CEMENTED TOTAL HIP-REPLACEMENT - INTEROBSERVER AND INTRAOBSERVER AGREEMENT

Three radiological methods are commonly used to assess the outcome of total hip replacement (THR), They aim to record the appearance of luce nt areas and migration of the prosthesis in a reproducible manner, Two of them were designed to monitor the implant through time and one to grade the quality of cementing, We have measured the level of inter- a nd intraobserver agreement in all three systems. We randomised 30 pati ents to receive either finger packing or retrograde gun cementing duri ng Charnley hip replacements, The postoperative departmental radiograp hs were evaluated in a blinded study by two orthopaedic trainees, two consultants and two experts in THR, The trainees and consultants repea ted the exercise at least two weeks later. We used the unweighted kapp a statistic to establish the levels of agreement. In general, intraobs erver agreement was moderate but interobserver agreement was poor, wit h levels similar to or less than those expected by chance. Our results indicate that such systems cannot provide reliable data from centres in different parts of the world, with various levels of surgeon evalua ting radiographs at differing time intervals, We discuss the problem a nd suggest some methods of improvement.