The availability of accurate and timely state predictions for objects in near-Earth orbits is becoming increasingly important due to the growing congestion in key orbital regimes. The Two-line Element Set (TLE) catalogue remains, to this day, one of the few publicly- available, comprehensive sources of near-Earth object ephemerides. At the same time, TLEs are limited by their corresponding low-fidelity physical models, introducing errors and uncertainty into state predictions. Previous literature has shown that filtering TLEs with batch least squares methods can yield significant improvements in long-term state prediction accuracy. However, this pro- cess can be highly sensitive to TLE quality which can vary throughout the year. It will be shown that remov- ing systematic biases in along-track position prior to state estimation can reduce post-fit position errors by an order of magnitude for selected satellites in the Medium Earth Orbit (MEO) regime.