My son is 12 years old. his recent xray shows primary thoracolumbar scoliosis of 13.2 concave to the left. does he need a back brace or what would the treatment be?

Depends on details: The pediatric orthopedic spine doctors usually consider a brace if the angle has reached 20-25 degrees and the teen still has significant years of growth left, or if the angle is less than 20-25 degrees but has rapidly progressed at least 5 degrees at the 4 to 6-month follow-up appointment. That means a follow-up scoliosis x-ray is important to do, usually twice a year.