DOS 2018

DOS Kongressen 2018 · 101 What is the Outcome of Bi-cruciate Versus Cruciate Retaining Total Knee Arthroplasty at 2-year Follow-up Assessed in a Randomized Controlled Trial? Anders Troelsen, Lina Holm Ingelsrud, Morten Grove Thomsen, Omar Muharemovic, Kristian Otte, Henrik Husted Department of orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Radiology, Copenhagen University Hospital Hvidovre Background: Bi-cruciate retaining (Bi-CR) total knee arthroplasty (TKA) intend to improve outcome by maintaining intrinsic ACL functions. Purpose / Aim of Study: The aim was to compare tibial implant migration and clinical outcomes of Bi- CR and CR TKA. Materials and Methods: This single-blinded parallel-group trial randomized 50 patients eligible for a CR TKA with intact ACL during surgery to receive a Bi-CR or CR TKA. Patients suspected to have ACL rupture were excluded. The primary outcome was the maximum total point motion (MTPM) measured with radiostereometric analyses at 2 years postoperatively. Patient-reported out- comes were assessed by the Oxford Knee Score (OKS; 0-48) and the Forgotten Joint Score (FJS; 0-100). Findings / Results: At 2 years postoperatively, RSA images were available for 45 patients and PROMs for 48 patients. The mean MTPM was 0.59 and 0.62 mm in the Bi- CR and CR groups, respectively (p=0.82). Two patients (2-year OKS: 41 and 43) receiving Bi-CR TKA were classified as migration outliers. The improvement in median OKS from preoperative to 2 years was 20.5 to 41.0 and 25.0 to 44.0 in the Bi-CR and CR groups, respectively. The mean FJS improved from 16.1 to 62.0 and 21.8 to 69.6 in the Bi-CR and CR groups, respectively. Neither absolute values at 2 years nor improvements showed statistically sig- nificant differences between the groups (p=0.07 and 0.96 for OKS; p=0.28 and 0.80 for FJS, respectively). Three patients (Bi-CR group) underwent ar- throscopically assisted manipulation between 3 and 4 months postoperatively. One patient sustained a tibial island fracture during primary surgery and was revised after 6 months. Conclusions: Stable fixation and excellent clinical outcomes of a Bi-CR TKA at 2 year follow-up, similar to a gold standard CR TKA, can be achieved, although a unique learning curve was identified. 42.