Abstract
Purpose
To identify the modes of failure after total knee arthroplasty (TKA) in patients ≤ 55 years of age and to compare with those ≥ 56 years of age in patients who underwent revision TKA.
Materials and Methods
We retrospectively reviewed 256 revision TKAs among patients who underwent TKA for knee osteoarthritis between January 1992 and December 2012. The causes of TKA failure were analyzed and compared between those ≤ 55 years of age and those ≥ 56 years of age. The age at the time of primary surgery was ≤ 55 years in 30 patients (31 knees) and ≥ 56 years in 210 patients (225 knees).
Results
A total of 453 TKAs were performed in ≤ 55-year-old patients between 1992 and 2012. Of these, 31 cases (7%) were revised. Their mean age was 50.6 years (range, 40 to 55 years) at primary surgery and the interval from primary TKA to revision was 8.6 years (range, 1 to 17 years). In the ≤ 55 years of age group, the most common modes of TKA failure was polyethylene wear in 14 cases (45%) followed by infection in 8 cases (26%) and component loosening in 5 cases (17%). The other conditions led to TKA failure were stiffness, periprosthetic fracture, malalignment, and osteolysis in one case each (3%).
Of the 11,363 TKAs that were performed in ≥ 56-year-old patients, 225 cases (2%) required a revision. The mean interval between the operations was 5.3 years (range, 0.1 to 18 years). The major modes of failure of primary TKA include polyethylene wear in 99 cases (44%), infection in 91 cases (40%), and component loosening in 26 cases (12%).
In both groups, the most common cause of failure was polyethylene wear, which was followed by infection and component loosening. There were relatively lower infection rate and higher loosening rate in patients ≤ 55 years of age, but the difference was not statistically significant (p > 0.05). The mean interval between the operations was shorter in the ≥ 56 years of age group (5.3 years; range, 0.1 to 18 years) than in the younger patient group (8.6 years; range, 1 to 17 years), but there was no notable intergroup difference (p > 0.05).
Conclusion
The main modes of failure after TKA in patients ≤ 55 years of age were polyethylene wear, infection and loosening, and there was no significant difference in the modes of failure after TKA between the two groups.
