The legacy constrained condylar knee prosthesis (LCCK, Zimmer.) is designed for primary and revision total joint arthroplasties that need additional stability due to ligament deficiency and to compensate for bone defects. In this follow-up we present our mid term results. Between November 1999 and January 2006 59 patients were provided with 67 LCCK knee endoprotheses. 38 prostheses were implanted in cases of revision surgery and 29 as primary implants. The mean patient age was 76 years (range 22–93). Indications for revisions were 20 aseptic loosenings, 11 late infections, 7 instabilities (5 cases due to polyethylene wear). Indications for primary arthroplasties were 16 severe valgus and 7 severe varus deformities, 5 cases of osteoarthritis after infection and 1 posttraumatic deformity. 36 femur components (54%) and 34 tibia components (51%) were augmented. 31 stems were fixed cementless, 15 stems were cemented (6 with an intermedullary plug). We evaluated the results prospectively with a clinical inspection and x-ray. Clinical rating systems used were the Knee society, SF-36 Quality of life and Womac score. The mean follow up was 5.6 years. 42 patients were examined, 10 questioned on the telephone, 3 deceased, 12 had to be revised and 2 were lost for follow-up.Introduction
Methods and Material
The operations were performed by 11 surgeons, with more than 80% done by 5 surgeons. 162 (74%) femur components and 181 (83%) tibia components were cemented. Patella resurfacing was performed in 135 (62%) cases. We evaluated the results prospectively with a clinical inspection, radiographs (AP and lateral, longleg standing, patella sunrise view), and the use of the Knee Society Score, Quality-of-Life Short Form-36 and WOMAC rating score. 149 patients were examined at a mean follow up of 5,9 years (range 4,1–8,2 years). 29 were questioned on the telephone, 29 deceased, 7 revisions had to be performed and 4 (2%) were lost to follow up.
Early complications included 12 haematoma, 10 wound healing problems, 5 early infections, 2 thrombosis and 1 non lethal pulmonary embolism. 7 revisions had to be performed: 3 late infections (2 one-stage revisions with synovectomy and exchange of polyethylene inlay, one two-stage revision with semi-constrained implant LCCK© Zimmer Inc.), 3 patella resurfacing due to anterior knee pain and 1 exchange of cemented tibia plateau due to aseptic loosening. Survivorship at 6 years including any reason of failure was 96,5%.