A tissue-resecting end effector includes an outer shaft having a hub housing, an inner shaft including a sun gear, and a drive assembly disposed within the hub housing. The drive assembly includes a first and second drivers disposed about the inner shaft distally and proximally of the sun gear, respectively. The drive assembly further includes a plurality of planetary gears radially disposed about and in meshed engagement with the sun gear between the drivers, and a locking clip proximal of the planetary gears and the sun gear, rotationally keyed to the second driver, and engaged with the first driver via at least one snap-fit engagement. The locking clip retains the drivers and the planetary gears in operable engagement with one another and the sun gear such that a rotational input provided to the second driver drives rotation of the inner shaft.