A COMPARISON OF IMPLANTATION QUALITY BETWEEN NAVIGATED AND CONVENTIONALLY IMPLANTED MOBILE BEARING UNICOMPARTMENTAL KNEE REPLACEMENTS

Abstract

The purpose of our study was to compare the alignment achieved by navigated mobile bearing unicompartmental arthroplasty with that of standard instrumentation. We looked at postoperative X-Rays of 18 unicompartmental mobile bearing arthroplasties performed by two surgeons. 12 of these performed by one surgeon, consisting of 6 navigated E-Motion™ mobile bearing knees and 6, Phase 3 Oxford™ unicompartmental mobile bearing knees. The remaining 6 were Phase 3 Oxford™ unicompartmental mobile bearing knees, performed by a different surgeon. Radiological measurements using the criteria in the Oxford™ manual were taken. All navigated E-motion™ components were within the defined Oxford™ parameters, while a quarter of both all the femoral and all tibial implants were malaligned using standard instrumentation. Our study shows that better and more consistent alignment was achieved when navigation was used for mobile bearing unicompartmental arthroplasty as opposed to the use of standard instrumentation.