2 Days Ago I Was In Bed Reaching For Something

2 days ago I was in bed reaching for something on the floor when I got the worse Charlie horse in thigh and calf. left leg since then the knee has been very swollen it hurts to straighten out the leg. And now it is very painful to walk on it. I had a partial knee replacement 3 yrs ago was told that it needs to be converted to a total replacement and there are bone spurs. What do you think? behind the knee is swelled up also.