Risk factors related to adjacent segment degeneration: retrospective observational cohort study and survivorship analysis of adjacent unfused segments.

Object: Adjacent segment disease (ASD) has been described as a frequent complication after a lumbar spinal fusion procedure, though its incidence and the factors related to its appearance are not well established. The radiographic signs that identify ASD in unfused segments may be a consequence of biomechanical changes induced by the fusion procedure. This study sought to analyse the incidence of radiographic changes (radiographic ASD) in all adjacent unfused segments, the clinical changes that require a second procedure (clinical ASD), and the risk factors of their appearance evaluated at different follow-up times.

Ossifying fibroma of long bones in adults: a case report.

Ossifying fibroma (osteofibrous dysplasia) is a rare fibro-osseous lesion made up of fibrous tissue with woven bone formation. It is most commonly found in the tibia and fibula of children ten years of age or younger. The most important differential diagnosis is monostotic fibrous dysplasia, which is radiologically similar but without woven bone rimmed by active osteoblasts like ossifying fibroma on histological examination.