DOS 2020

190 · DOS Abstracts Longterm follow-up with a Custom Triflanged Implant In Reconstruction Of Severe Acetabular Bone Loss With Pelvic Discontinuity After Total Hip Arthroplasty. Nikolaj Winther, Michael Mørk Petersen, Jens Styrup Department of Orthopaedic Surgery, Rigshospitalet Background: Revision of a failed total hip arthroplasty with massive acetabular bone loss and pelvic discontinuity is a reconstructive challenge. Treatment op- tions includes morselized bone graft and structural allograft used with unce- mented hemispherical acetabular components, cages, porous metal augments, and cup- cage reconstruction. A custom-made triflanged implant has recently been introduced as a new option of treatment. Purpose / Aim of Study: The purpose of this study was to evaluate the use of a Custom made Triflanged Implant in cases with pelvic discontinuity. We moni- tored healing rate, migration and overall survivorship defined as revision of the implant for any reason. Materials andMethods: We reviewed 42 consecutive patients, mean age 68.7 (48-85 years) with a failed THA and pelvic discontinuity. Mean follow-up was 45 (12-120) months. The implant for acetabular reconstruction was custom manufactured on the basis of a three- dimensional model of the hemi-pelvis created from computed tomography (CT). The Harris Hip score was performed and the acetabular bone defects were all classified as type V according to the Gross classification. Center of rotation (COR) was calculated. Postoperative ra- diographs were analyzed in relation to: Healed or unhealed discontinuity and stable/unstable fixation. Findings / Results: Mean per-operative blood loss was 1500 ml (235-6500) and mean surgery time was 147 min. (72-331). COR was established in 36 of the patients and no major intraoperative complications occurred. Mean Harris Hip score was 80 (47-96). The discontinuity healed in 40 (95%) of the cases. Thirty-five patients (83%) had no additional procedures. Seven patients ex- perienced dislocation (16%) five for these treated with a constrained liner. We observed two septic loosening (5 %) revised in 2 stage procedures, and one re- infection (2%) treated with life-long antibiotic. 40 (95%) of the implants was defined as stable without any revision for aseptic loosening. Conclusions: The 3D costum made Triflanged Implant makes it possible to op- timized screw and implant positioning with high accuracy and with rigid fit on bone fixation thus permitting healing of the discontinuity and biological fixation of the acetabular component. 169.