A randomized trial of steroid injections for back pain has shown that they are no more effective than a placebo. Because the long-term benefits of surgery remain unproven and pain medicines often have serious side effects, doctors have increasingly turned to steroid injections to treat lumbosacral radiculopathy, a common cause of back pain. The condition stems from damage to the discs between the vertebrae that often leads to sciatica, numbness or pain in the legs.