<unk>  of the elbow, after comminuted fracture and arthroplasty. comminuted fracture and arthroplasty. During the early stage, an x-ray will not be helpful because there is no calcium in the matrix. (In an acute episode which is not treated, it will be 3– 4 weeks after onset before the x-ray is positive.) Early laboratory tests are not very helpful. Alkaline phosphatase will be elevated at some point, but initially may be only slightly elevated, rising later to a high value for a short time. Unless weekly tests are done, this peak value may not be detected. It is not useful in patients who have had fractures or spine fusion recently, as they will cause elevations. The only definitive diagnostic test in the early acute stage is a bone scan, which will show<unk>  7 – 10 days earlier than an x-ray. The three-phase bone scan may be the most sensitive method of detecting early<unk>  bone formation.<unk> wever, an abnormality detected in the early phase may not progress to the formation of<unk>  bone. Another finding, often misinterpreted as early<unk>  bone formation, is an increased (early) uptake around the knees or the ankles in a patient with a very recent spinal cord injury. It is not clear exactly what this means, because these patients do not develop<unk>  bone formation. It has been hypothesized that this may be related to the autonomic nervous system and its control over circulation. When the initial presentation is swelling and increased temperature in a leg, the differential diagnosis includes thrombophlebitis. It may be necessary to do both a bone scan and a venogram to differentiate between<unk>  and thrombophlebitis, and it is even possible that both could be present simultaneously. In<unk> , the swelling tends to be more proximal and localized, with little or no foot/ankle edema, whereas in thrombophlebitis the swelling is usually more uniform throughout the leg.
Heterotopic ossification
Intramembranous ossification
Metastatic calcification
Ectopic calcification
Dentin dysplasia
Exostosis
Hypercementosis
Osteophyte