Implant Malposition Resulting in Early Failures
- Concerns with UKA are early failure of the femoral or tibial components.
- The main cause of early failure is malpositioning of components with overcorrection or undercorrection of limb alignment.
Failure of UKA
Tibial Component Malalignment
- Coronal malalignment of the tibial component beyond 3° predisposed to failure
Femur Component Malalignment
- Malalignment of the femoral component has been found to cause femoral fracture, patellar impingement and tibial component loosening.
Excessive Posterior Slope
- Excessive posterior slope (>7°) of the tibial component has been linked to tibial component loosening, anterior cruciate ligament (ACL) rupture and abnormal stress forces on the periprosthetic bone.