Problems from the musculoskeletal system are one of the most common reasons for disability and sick leave. These problems include low back pain. Low back pain affects as many as 8 out of 10 individuals at some point in life. In most people it is quickly transient with little, or only short-term, impact on function and quality of life. In some individuals, the problems can become long-lasting and significantly impair the quality of life. When analgesic and physiotherapeutic treatment have been tried and the problems are still not manageable, and have lasted more than a year, surgical treatment consisting of fusion surgery of the painful part of the spine may come in question. In Sweden, approximately 600 fusion surgeries are performed annually for low back pain. There are a few randomized studies comparing fusion surgery for low back pain with non-surgical treatments, but these have showed different results. The effect of fusion surgery on low back pain is therefore uncertain. Surgical treatments brings with it a clear placebo effect. Other studies on pain in other parts of musculoskeletal system than the back has not been able to show that a surgical treatment is always better than placebo surgery. This has called into question the effect of surgery on many painful conditions of the musculoskeletal system. No placebo-controlled surgical studies have been done on fusion surgery for low back pain. A placebo surgical controlled study is the only way to ascertain whether fusion surgery is the right treatment for low back pain. In this study, 90 individuals will undergo surgical treatment for low back pain. After surgical exposure, the surgeon will be informed whether fusion surgery should be performed or not. Half of the patients will undergo a fusion procedure with implants and the other half will not undergo the fusion procedure and will not receive implants. Treatment randomization will be performed during surgery, and the individuals undergoing treatment and the staff taking care of the individual after surgery will be blinded for treatment allocation during 6 months. That means that the individuals participating in the study and the staff who meet the individuals after surgery won't know if the individual had fusion surgery or no fusion surgery until after the 6 month follow-up. The most important outcome of the study is the result of a questionnaire-based measure of back function answered by the participating individuals.