It is normal to have residual pain after most back surgeries. This is generally caused by the formation of scar tissue, which is a natural part of the healing process, reports back.com.
Scar tissue does not have nerve endings, but as it forms, it usually presses against nerve roots that cause recurring or worsened pain 6-12 weeks after surgery. This scar tissue formation is referred to as epidural fibrosis. This type of pain may be managed through physical therapy, specifically postoperative stretches that break up scar tissue and improve mobility, says back.com. However, if the pain persists longer and is more intense, the dissection of the nerve root may have exacerbated the original injury. It would be wise to consult one's doctor for more information on pain relief and postoperative physical therapy.