STAGED SURGICAL RECONSTRUCTION OF MASSIVE PELVIC DEFECT

Abstract

Purpose of the study— to illustrate on a particular clinical case an option of treatment for patients with severepelvic defects by a staged surgery: vascularized bone grafting and revision arthroplasty using custom made implant produced by laser sintering based on layered 3D-visualisation. Material and Methods.Female, 61 years old, was admitted to clinic in 2016 with aseptic loosening of acetabularcomponent and polyethylene insert wear following arthroplasty with total cementless prosthesis. Revision arthroplasty was made with hemispherical augment and anti-protrusion ring. On day 7th after the surgery a dislocation of prosthesis head, pubic bone fracture, migration of acetabular component and bone defect with pelvic discontinuity occurred due to trauma. To restore continuity of the pelvic ring and supportability of the lower limb the authors performed a staged multisession procedure: removal of prosthesis, free vascularized bone grafting by costal vascular pedicle graft and plating fixation of the pelvis. 6 months after the first stage a custom made prosthesis was implanted. Such prosthesis was produced based on a 3D pelvis reconstruction model by layered visualization and with evaluation of bone density on the Hounsfield scale and was printed on 3D-printer by laser sintering from LPW-TI64-GD23-TYPE5 titanium. Results.The authors did not observe any septic complications, dislocations and components migration in theearly postoperative period. Function was assessed by Harris Hip Score. Scores prior to arthroplasty by a custom made implant was 12 points, one month postoperatively — 30 points, three months postoperatively — 51 points, six months postoperatively — 74 points. Life quality scores by SF-36 were reported as follows: prior to surgery РН — 21.32; МН — 40.92; one month postoperatively РН — 40.66; МН — 55.80; three months postoperatively РН — 52.14; МН — 57.81; six months postoperatively РН — 62.46; МН — 72.08. Conclusion.Vascularized bone autoplasty allows to restore pelvic continuity, and the use of custom madeimplants — to restore supportability of the lower limb and hip function in case of an extensive pelvic defect.