Lumbar fusion is recommended for the treatment of fractures, instability due to degenerative disease, tumours and other ailments that affect the stability of the spine. This is the latest promising measure when other treatments (such as girdles, massages, measures of postural improvement, anti-inflammatories and acquisition of an adequate weight) have not been successful. It is a delicate surgery that usually lasts from four to six hours and is performed under general anaesthetic. It also requires complementary postoperative rehabilitation.