A320-200 pilot reported during the landing flare around 50 feet they lost all lateral control authority and upon touchdown they transferred aircraft control to the captain who was able to stop the aircraft and taxi to the gate.

Narrative

After an uneventful flight; we were landing with a gusting to 15 knot crosswind on XXC. When I put in my de-crab crosswind controls in the flare around 50 feet; my rudder pedals broke/unlocked and I lost all lateral control authority. This lack of control resulted in a slightly firmer than normal touchdown and I quickly transferred aircraft control to the Captain who was able to uneventfully and without issue bring the aircraft to a stop and to the gate. Upon inspection; I found that the FO's rudder pedals moved forward/aft with no resistance and it appeared some aspect of the spring adjuster had broken or become disconnected. We gave the aircraft to maintenance and wrote up the issue. A following write up included that the FO's brake reservoir had become completely depleted. The aircraft experienced a serious control malfunction with the FO's controls; which in a different phase of flight or with slower pilot action to react and transfer aircraft control could have had potentially disastrous results. I wanted to highlight it to safety via this report in case this becomes a trend; because of the severity of the malfunction. Should this occur on both sets of rudder pedals simultaneously; complete loss of control on the ground would result.