CLINICAL IMPACT OF TIBIAL MALALIGNMENT

Tibial component malalignment has been specifically associated with adverse clinical events. In a study of 2,125 patients (3,152 knees) undergoing TKA between the years of 1983– 2000, it was found that tibial malalignment was a strong predictor of the need for revision, with more than 3° of tibial component varus alignment increasing the odds of implant failure by roughly 17x (Hazard Ratio = 17.2, p < 0.0001).¹⁶  This same study found that the combination of tibial malalignment and obesity indicated an especially strong risk for revision, with a relative risk of approximately 168 (p < 0.0001), suggesting that a well-aligned tibial component could significantly reduce revision rate among obese patients.¹⁷

Given that approximately 87% of Canadian TKA patients are obese or overweight¹⁸ (with the U.S. likely sharing similar statistics), achieving accurate tibial component alignment is particularly important.

Moreover, relatively little clinical research has been done regarding posterior-slope alignment (an angle which the KneeAlign^® system enables the surgeon to measure and set), with available data suggesting that the prevalence of malalignment in this dimension may even be worse than varus/valgus malalignment.¹⁹