In '99, spiral fractured one lower leg bone and shattered the other. Dr says it's healing nicely still. Still, on occassion have extreme pain in leg. Have lots of pins and metal in leg. This why?

X-ray . This is really impossible to answer intelligently without looking at good quality ap and lateral x-rays of your tibia and/ or ankle.A second opinion is never a bad idea. Gl!
Severe Injuries. Regardless of the ijury, it never heals perfect. As an expected long term complication of your injury, chronic pain may be expected. The expectation of healing perfectly and not having any pain is not realistic. Occasional pain and some dysfunction is a realistic expectation.