Abstract
Introduction
Total knee arthroplasty (TKA) has proven clinical success with reported longterm survivorship of 92% in the elderly population. Concerns regarding increased loosening rates and potential need for multiple revision surgeries in patients younger than 60 years have traditionally discouraged TKA in younger patients. The purpose of this study was to review the longterm clinical and radiographic results of patients under the age of 45 yrs who underwent a total knee replacement.
Materials and Methods
A retrospective review of our institutional database was performed between January 1996 and December 2004 The criteria for inclusion in the study were as follows: age 45 years or younger at index arthroplasty, cemented condylar prosthesis, and a minimum follow-up of 9 years. A total of 39 consecutive primary cemented condylar knee arthroplasties in patients with end stage arthritis were performed in 36 patients who were 45 years or younger. The median length of followup was 13.6 years. There were 18 men and 21 women. The mean age was 40.6 years (range, 28–44). There were 23 right, 16 left, and 3 bilateral procedures. The mean body mass index was 31.2 kg/m2
Clinical and radiological evaluations were performed before surgery and at 6 weeks, 3 months, 1 year and every 2 years subsequently. Knee scores were calculated using the Knee Society Clinical Rating Scores (KSCRS), SF-12 and WOMAC scores to assess pre, and post-operative function. Postoperative anteroposterior and lateral views were assessed for femoral and tibial component position, alignment, and presence or progression of radiolucent lines at the bone-cement and prosthesis-cement interfaces
Statistical analysis was performed using the 2-sample test or Wilcoxon rank sum test for comparison of continuous variables. Kaplan-Meier analysis of implant survival was performed with failure defined as femoral component revision due to any cause.
Results
There was a statistically significant improvement in clinical outcome measures between pre and post-operative SF-12, WOMAC, and KSCRS validated scoring systems. 41% of patients had previous surgery prior to the TKA with 87% of patients receiving a cruciate sacrificing TKA and 64% of patients receiving a patellar resurfacing. There were 4 revisions in total, 2 patients were revised for pain, 1 for instability and 1 for infection treated with a single stage revision, the average time to revision was 3 years. There were no cases of aseptic loosening with an overall survival of 89.8% at an average follow-up of 13.6 yrs. The Kaplan-Meier estimated survival rate to revision was estimated to be % at 10 years and % at 15 years Radiographic assessment did not reveal any evidence of component migration, malalignment or radiolucencies at final follow up. There was no evidence of progressive radiolucencies noted on zonal analysis around both tibial and femoral components on serial radiographs in any patient.
Conclusion
Excellent clinical outcomes are reported for patients 45 years of age or less who have undergone TKA. For the young patient who is not a candidate for other joint conserving or preserving procedures, Total Knee Replacements provide a successful longterm outcome.
