Low back pain: Author's reply

EDITOR—Bamji's views reflect the ongoing active discussion on the contribution of the sacroiliac joint to pain in this region. Although, as he points out, the sacroiliac joint has extreme mechanical strength, it exists within the pelvic ring; instability at the symphysis (common in women and active men) may result in pain further along the kinetic chain—including the innervated and partly synovial sacroiliac joint. Sacroiliac pain may arise through dysfunction through minute laxity or instability, or pain due to ligamentous irritation without any instability.

Any further comments are based on differences in clinical perspective in the face of a vacuum of evidence. It is a difficult joint to assess. The history, including potential mechanisms for injury (such as hurdling, or football), and examination, in particular to exclude other sources of pain, are crucial. Approaches to examination of the joint have been proposed but remain unvalidated. Pain truly arising from the sacroiliac joint should, in my view, be considered as one of the differential diagnoses of pain in the pelvic region, particularly in young and active patients. Nevertheless, “sacroiliac pain” is an overdiagnosed condition, and it should be diagnosed only in the absence of any other cause for pain, although conditions can coexist.