Management of Bone Defects in Revision Total Knee Arthroplasty

Background: Bone defects remains a frequent complication of total knee arthroplasty (TKA). The management of these defect in the revision TKA is a surgical challenge. The aim of the work: This study aimed to evaluate the clinical and radiological outcome of the bone defects management in revision TKA (rTKA). Patients and Methods: Thirty patients with bone defects after TKA were included. All were classically evaluated by history taking, clinical examination, laboratory and radiological workup. Then submitted to rTKA with management of bone defects by different methods. They were followed up at 6 weeks, 3 months, 6 months then yearly. The clinical outcome was measured by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, range of motion (ROM), leg raising test and clinical assessment of limb alignment. The radiological outcome by limb & component alignment. In addition, any complications were recorded. Results: The side of surgery was mainly the right side (66.7%). The bone defect was mainly femoral (50.0%), then tibial (40.0%) The majority of cases were Anderson class IIA (53.3%) and aseptic loosening was the major cause (56.7%). Metal augments was the commonest treatment method (50% of cases) followed by bone graft in 16.7%. There was significant increase of postoperative ROM (100) and WOMAC score (85.9) after surgery than corresponding values before surgery (45 and 19 respectively). Deep infection was confined to cases with cone and metal block, while deep vein thrombosis (DVT) was confined to metal block and metal augments. The postoperative WOMAC score was significantly different between management methods (the highest score was recorded with metal augments and metal blocks (90 and 90.5 respectively), while the lowest was registered with the cone (70.7). Conclusion: The management method of bone defect had significant impact on complication type and operative time, but not on functional outcome following revision TKA.