What might be going on? hip replaced anterior 2019. lately i've been having pain at top of thigh, anterior. today was very sharp and lasted about 5 minutes. pain is like a cramp and sometimes happens when i stretch that leg. 8/10 pain when it occurs?

Anterior approach can involve the cutaneous or the femoral nerve itself. The nerve can be cut or the nerve could become entangled with scar tissue. Your symptoms are more consistent with the later. The nerve could be more involved with scaring creating more and constant symptoms . Ultrasound treatments followed by deep message to loosen the scar tissue. Unusual to take this many years to present