title: Long-term followup after mobile-bearing total knee replacement.
abstract: Clinical and radiographic analyses and survivorship were done on the initial cementless series of 309 posterior cruciate-retaining meniscal-bearing and rotating-platform New Jersey LCS total knee replacements followed up for 10 to 20 years (mean, 12.4 years). Clinical results in patients surviving at least 10 years using a strict knee scoring scale were similar for posterior cruciate ligament-retaining and posterior cruciate ligament-sacrificing designs. Good to excellent results were seen in 97.9% of primary posterior cruciate-retaining-bearing prostheses and in 97.9% of primary rotating-platform prostheses. Radiographic analysis of minimum 10-year followup radiographs showed generally stable fixation of all components with gross migration seen in one tibial component (0.6%) in a patient with a failed high tibial osteotomy. Significant osteolysis was present requiring bearing exchange and bone grating in three patients with cementless rotating-platform prostheses (1.8%) who had multiple knee surgeries at an average of 10.2 years from the index surgery. Survivorship of the primary cementless posterior cruciate-retaining meniscal-bearing prostheses with an end point of revision for any mechanical reason was 97.4% at 10 years and 83% at 16 years; using an end point of a poor clinical knee score, the survivorship was 98.9% at 10 and 16 years, respectively. Survivorship of the primary cementless rotating-platform prostheses with end points of revision for any mechanical reason or a poor clinical knee score was 98.3% survivorship at 10 and 18 years, respectively. In the current study, no cementless rotating-bearing patella loosened, fractured, or dissociated in patients without prior knee surgery although one cementless rotating-bearing patella (0.6%) in a patient who had multiple knee surgeries wore through the inferior marker wire after 10.8 years, causing metallosis that required revision.
authors.affiliation: Departmentof Orthopaedic Surgery, UMDNJ-New Jersey Medical School, Newark, USA. fbuechelmd@hotmail.com
authors.forename: Frederick F
authors.initials: FF
authors.lastname: Buechel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation; D016019:Survival Analysis