Page 72 - Reconstructive Techniques in Musculoskeletal Tumor Surgery

Chapter 4
Abstract
Background: Reconstruction of periacetabular defects after pelvic tumor resection ranks among the most challenging procedures in orthopaedic oncology, and reconstructive techniques are generally associated with dissatisfying mechanical and non-mechanical complication rates. In an attempt to reduce the risk of dislocation, aseptic loosening, and infection, we introduced the LUMiC prosthesis (implantcast, Buxtehude, Germany) in 2008. The LUMiC prosthesis is a modular device, built of a separate stem (hydroxyapatite-coated uncemented or cemented) and acetabular cup. The stem and cup are available in di erent sizes (the latter of which is also available with silver coating for infection prevention) and are equipped with sawteeth at the junction to allow for rotational adjustment of cup position after implantation of the stem. Whether this implant indeed is durable at short-term follow-up has not been evaluated.
Questions/purposes: (1) What proportion of patients experience mechanical complications and what are the associated risk factors of periacetabular reconstruction with the LUMiC after pelvic tumor resection? (2) What proportion of patients experience non-mechanical complications and what are the associated risk factors of periacetabular reconstruction with the LUMiC after pelvic tumor resection? (3) What is the cumulative incidence of implant failure at 2 and 5 years and what are the mechanisms of reconstruction failure? (4) What is the functional outcome as assessed by Musculoskeletal Tumor Society (MSTS) score at nal follow-up?
Methods: We performed a retrospective chart review of every patient in whom a LUMiC prosthesis was used to reconstruct a periacetabular defect after internal hemipelvectomy for a pelvic tumor from July 2008 to June 2014 in eight centers of orthopaedic oncology with a minimum follow-up of 24 months. Forty-seven patients (26 men [55%]) with a mean age of 50 years (range, 12 – 78 years) were included. At review, 32 patients (68%) were alive. The reverse Kaplan-Meier method was used to calculate median follow-up, which was equal to 3.9 years (95% con dence interval [CI], 3.4 – 4.3). During the period under study, our general indications for using this implant were reconstruction of periacetabular defects after pelvic tumor resections in which the medial ilium adjacent to the sacroiliac
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