Abstract
Background and purpose - The number of revision total knee arthroplasties (TKA) is continuously increasing, leading to a growing need for reliable management of metaphyseal bone loss. We evaluated patients operated with a TKA using metal metaphyseal sleeves for bone defects with a minimum 5-year follow-up. Patients and methods - 37 patients had been operated on. 3 patients died and 3 patients were lost during follow-up. Of the 31 remainders (20 women), 9 had been operated on with a primary TKA and 22 with a revision TKA at the index surgery. The mean age at surgery was 69 (54-89) years and the mean follow-up time was 7.4 (5-12) years. Bone defects were classified according to the Anderson Orthopaedic Research Institute classification (tibia: type I n = 9, type II n = 5 and type III n = 17; femur: type I n = 12, type II n = 3 and type III n = 16). Results - At final follow-up one-third experienced an improvement concerning walking aids and walking distance. Except for 1 patient, all had full extension and a mean knee flexion of 110 (90-140) degrees. VAS pain at rest was 13 (SD 25) and on movement 30 (SD 31). 7 patients were reoperated due to: infection (n = 4), periprosthetic fracture (n = 1), skin necrosis (n = 1), and wound rupture (n = 1). The cumulative 5-year survival rate for reoperation was 77% (CI 63-92) and for revision 97% (CI 91-100). At the time of final follow-up, the sleeves showed good osseointegration with no signs of progressive radiolucency or migration. Interpretation - Titanium sleeves are a promising option in managing difficult cases with metaphyseal bone defects in TKA, providing a stable construct with good medium-term radiographic outcome.