Goldie Sayers is to have surgery to repair a torn elbow ligament that cost her a chance of a medal at London 2012.
The 30-year-old had to watch the women's javelin final, won by Barbora Spotakova, from the sidelines after failing to qualify.
"I gave it everything to the point where I ripped a ligament off the bone, so I do need surgery now," she said.
Had she been able to take part, a repeat of her British-record throw of 66.17 metres would have won silver.
"It was quite a painful experience watching one of the lowest medal-winning distances for a long time, knowing I was in the best shape of my life three weeks ago," Sayers told BBC Radio Cambridgeshire.
"I wanted to watch, from a professional development standpoint you do learn a lot from watching very objectively, but it was hard.
"It's very easy to say I would have done x, y and z but knowing that I threw 66 metres in dreadful conditions, in rain and a headwind, I think there was a lot more in me."
Sayers indicated she would compete at the next Olympics in Rio de Janeiro following her gallant attempt to qualify for the final - but has now set herself another goal beyond 2016.
She continued: "I'm definitely going to carry on to Rio and I sat there reflecting 'wouldn't it be nice to win the World Championships in 2017 in this stadium?'
"I'm 30, but I'm improving every year and there's no reason why I can't medal in four years."
Sayers will have surgery next week and then faces several months of rehabilitation work.
"Whenever you have an injury, it does change the mechanics (of throwing) slightly," added Sayers.
"There'll be trials and tribulations along the way but I've had all sorts of surgery so I know the score on that."