[Transient painful lumbar blocks].
Recurrent painful locking of the lower back is suggested as an appropriate term for designating sudden episodes of jabbing low back pain with locking of the spine occurring in the absence of unusual exertion, resolving within one or two minutes, and recurring many times over several weeks or months. This retrospective study included 20 outpatients classified as having recurrent painful locking of the lower back between 1978 and 1992. Inclusion criteria were availability of roentgenograms taken at the time of the acute symptoms and a follow-up of at least two years. Two typical cases are reported with diagrams to show the timing of recurrent painful locking of the lower back with respects to other low back symptoms. Mean age at onset was 56 years. Seventy per cent of patients were females. A 10-year to 30 year history of lumbago was found in every case. Recurrent painful locking of the lower back occurred substantially later than lumbago suggesting that it denoted more advanced damage to the lumbar spine. Pathophysiologic hypotheses are discussed: the causative lesion may be a mobile flap at the posterior aspect of the anulus. In most patients, the symptoms resolved within six months.