Quick ball joint question

If the threaded ball joint stud turns with the nut, then does that mean that I need to replace it? And if so, for the lower ball joint do I need to replace the steering knuckle or can I remove the joint from the knuckle? This is for an 89 crx and these are on the front.

This is an old thread, but for future referance: Yes and Yes (the balljoint is shot and you can remove it from the knuckle)