Sources and patterns of pain in lumbar disc disease: revisiting Francis Murphey's theory.

Object: Francis Murphey's theory was analyzed to determine whether or not his opinion is evidence-based medicine and whether or not it can be applied clinically.

Methods: The English literature was reviewed using Medline in reference to Dr. Murphey's theory of discogenic chronic LBP, which was first postulated in 1967. Deductive and inductive logic was utilized for the evaluation of his theory. We reviewed and analyzed his unprecedented study of the annulus fibrosus (AF) and posterior longitudinal ligament (PLL) under local anesthesia that was presented to the Congress of Neurological Surgeons in 1967 and 1972.

Results: He reported that: "It is found that the posterior longitudinal ligament and the remaining annulus fibrosus over the herniated discs are also exquisitely tender; even the slightest pressure on them produces pain." We noticed that in Dr. Murphey's presentation, he did not disclose any hard data, yet he concluded: "when an incomplete tear in the annulus occurs and if the tear is in the midline posterior, a fragment of nucleus will protrude in this tear, stretching the annulus and posterior longitudinal ligament, causing midline back pain. If the tear in the annulus is lateral, the pain is over the sacroiliac joint in the buttock and hip, and 20% of the patients in the lower abdomen, groin or testicle on that side."

Conclusions: Because of a flaw in his understanding, in our opinion the unproven mechanical theory of discogenic LBP is weak inductive logic and does not justify discography and intra-discal procedures.