A bump on the back after lumbar spine surgery may be related to normal postoperative wound swelling, poor wound drainage, abnormal coagulation mechanism, wound infection and other factors. 1. Normal postoperative wound swelling: During the recovery period after surgery, due to the newborn of granulation tissue, inflammatory factor exudation and other factors, it may lead to local incision swelling, which is manifested as the phenomenon of a bulging bag on the back. If there are no other abnormalities, there is generally no need to intervene in the treatment, and the swelling will gradually subside with the passage of time. 2. Poor wound drainage: improper care after lumbar spine surgery, poor drainage of exudate, resulting in the accumulation of exudate in the incision, can also cause the phenomenon of the wound bulge in the operation area, usually need to drain the treatment. 3. Abnormal coagulation mechanism: after lumbar surgery, there is more blood seepage in the wound and blood accumulation, which is manifested as the phenomenon of a raised bag on the back. A small amount of blood can be absorbed and disappear on its own. If the symptoms continue to be unrelieved, the patient should go to the hospital as soon as possible for puncture to discharge the blood. 4. Wound infection: when the waist wound secondary bacterial infection, abscess can be formed in the wound, resulting in bulging bag phenomenon, accompanied by wound pain, skin temperature and other symptoms. You need to incise and drain the pus, remove the necrotic tissue, change the dressing regularly, and take amoxicillin, cefaclor and other antibiotics, intravenous ceftriaxone sodium and other drugs if necessary. The waist did a minimally invasive surgery two months wound a bag may also be other reasons, please go to the local hospital in time, active diagnosis and treatment.