Hi dear thanks for the query
During the period of three months the fractures
might have healed and in near normal position. The remnant pain could be due to some form fibrous healing around the sacral joints. Some times could be for prolonged periods
but it is not a serious problem. Regarding the weakness in you legs I would advice you get nerve
conduction studies of both lower limbs
after consulting your orthopaedic doctor. Continue the recommend exercises and do not loose hope. You will be having good recovery.