[Osteoid Osteoma of the Vertebral Column]

The peculiarities of osteoid osteoma of the spine occurring most frequently during adolescence are pointed out and contrasted to the benigne osteoblastoma, based on 5 observations and on studies of the literature. The nidus is usually located excentrically and exceptionally even intrarticular. Two foci may occur side by side or one after another, and the adjacent vertebral end plates may be involved. Spontaneous subsiding of pain is possible. The dorsal portions of the lumbar spine are diseased occasionally under the clinician picture of tight hamstrings, most often, however, with a painful reactive scoliotic position of the spine with the concavity always to the involved side. Spontaneous pain and local joint tenderness do precede the x-ray manifestations for many months. The history of pain prior to diagnosis still exceeds one year in the average. The x-ray findings are extraordinary polymorphe. A high awareness of suspicion ought initiate repeated examinations with x-ray and scintigraph. Lack of pains and disappearance of the reactive malpositions of the trunk may be expected only after resection of the nidus. It's preoperative detection may cause considerable difficulties as well as the correct postoperative histological diagnosis in the absence of the relevant material. The most frequent misdiagnosis is low grade osteomyelitis which has been true with the authors who describes first the syndrome of tight hamstrings.