Implant Migration and Failure in Total Knee Arthroplasty is Related to Body Mass Index and Tibial Component Size
Section snippets
Materials and Methods
This is a retrospective review of clinical and radiographic observations in 2 cohorts of primary AGC TKAs. First, we examined all primary AGC TKAs performed for osteoarthritis (OA) at our center between 1983 and 2004 with loosening and failure as the end point. Second, a cohort of 81 primary AGC TKAs, performed in Sweden, had previously had RSA beads implanted, and this data set served as a cohort with implant migration as the end point.
Statistics
Significant divisions in the stresses and tibial component alignments were determined with a regression tree analysis to determine break points in the data where failure rates were increased. These respective calculated tibial stresses and tibial component alignments and their respective failure rates were compared by Cox proportional hazards regression. A P value of .05 was considered significant.
Results
There were 22 MB and 32 AP revisions for aseptic loosening (overall failure rate, 0.8%) at a mean of 3.1 years post-TKA. The statistically significant breakdown of the effects of the stress categories and tibial component alignments is reported in Table 1. With only 524 knees in the AP cohort, tibial component alignment stratifications and stresses could not be compared independently. Therefore, all tibial component alignments were combined for the AP components and presented as estimated
Discussion
Aseptic failure of TKA implants is a multifactorial cascade of events with loosening as the final result. Polyethylene wear 3, 4, 13 with resulting debris and the ensuing inflammatory response have been a leading cause of implant loosening. Wear reductions have largely been achieved through improved sterilization techniques in oxygen-free inert environments [13], improved locking mechanisms, compression molding the polyethylene resin vs machining existing bar stock [7], and nonmodularity 8, 9.
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Modular Tibial Stem Use and Risk of Revision for Aseptic Loosening in Cemented Primary Total Knee Arthroplasty
2021, Journal of ArthroplastyCitation Excerpt :These factors were included as part of the propensity-score matching criteria prior to evaluation of the revision outcome to mitigate potential indication bias and confounding. While there have been reports of higher rates of aseptic loosening of the tibial component [14,19,34] and increased stress on the proximal tibia [17,18] in patients with obesity, Crawford et al [35] found only one case of aseptic loosening in 1859 patients with a BMI ≥35 kg/m2 who underwent primary TKA with a standard tibial base plate and high viscosity cement. Similarly Parratte et al [11] randomized primary TKA patients with a BMI >30 kg/m2 to either receive a tibial stem or not and failed to observe a difference in risk of all-cause revision and revision for aseptic loosening at 2 years.
The effect of surgical alignment and soft tissue conditions on the kinematics and wear of a fixed bearing total knee replacement
2019, Journal of the Mechanical Behavior of Biomedical Materials
Unrestricted research support came from Biomet, Inc, Warsaw, Ind.