Most likely your husband will have an MRI with a contrast dye to see what’s going on inside the spinal canal. There could be many potential problems causing this new development.
The symptoms suggest pressure on the spinal cord. Although very rare, a hematoma could be the source of the problem. A hematoma is a pocket of blood from internal bleeding during the operation. Usually patients have symptoms with this right away in the postoperative period.
But in some very unusual cases, delayed hematoma can cause the kind of symptoms you reported. Neurologic deficits can occur days to weeks after the spinal surgery. You were right to bring him to the hospital quickly. Immediate surgery may be needed to relieve the pressure and prevent permanent damage.
Your husband will likely have a short stay in the hospital until he is stabilized. He may go to a transition unit where he will be in a rehab program. Or he may be sent home and attend rehab as an out-patient.