Complex primary or revision TKA may require the use of a resection type prosthesis to address major bone loss and soft tissue deficiencies. The aim of this retrospective study is to evaluate the clinical and radiographic outcomes of salvage knee reconstructions in a larger cohort and longer follow-up than previously reported. We therefore present the results of 66 cases treated with the Finn/OSS knee system with an average follow-up of 5years (range 2-12). Indications included 63 revision cases and three primary interventions with either massive bone loss and/or soft tissue deficiency. At final follow-up the average knee society score had significantly improved from 46 preoperatively to 73, and the function score improved from 27 to 47 points. Four cases needed to be revised: one for recurrent infection, two for aseptic loosening and one for implant breakage. Nine patients underwent minor reinterventions; including five cases with irrigation and debridement for prolonged wound drainage, two patellar realignment procedures and two extensor mechanism repairs. Two patients developed a peroneal nerve palsy. Overall implant survivorship with revision as the endpoint was 92% at 5 and 10years. We conclude that the use of a resection prosthesis in the complex primary and revision TKA leads to acceptable results, but the complication rate is relatively high.