Partial transient osteoporosis

Abstract

Regional transient osteoporosis (algodystrophie décalcifiante) has been recognised as a clinical and radiological syndrome in a number of reports published between 1947 and 1968 [16, 17, 23, 24, 11]. The condition is characterised clinically by the development of severe and often incapacitating pain around a major joint, usually the ankle, the knee, or the hip in middle-aged and elderly adults. Haematological and biochemical studies are essentially unrewarding. Radiological examination initially reveals no abnormality, but one or two months after the onset of symptoms widespread osteoporosis is demonstrated around the affected joint. The clinical symptoms resolve spontaneously within approximately four to ten months with subsequent remineralisation of the osteoporotic areas. In about a third to a quarter of cases the cause is unknown (idiopathic form). In the remainder, a history of minor or major trauma, including surgery, is elicited in more than half the patients, suggesting the entity to be analogous to Sudeck's atrophy. Other apparent precipitating factors include neuralgia, herpes zoster, hemiplegia, and vascular disturbances. These ‘secondary’ or ‘reflex’ forms do not differ from the idiopathic form. Transient osteoporosis of the hip or knee is more commonly idiopathic, whereas involvement of the ankle or foot is often secondary to trauma. In most instances the osteoporosis spread ultimately to produce the classical pattern of diffuse peri-articular demineralisation, especially around the weight-bearing joints of the lower limb.

Two different radiological manifestations of partial transient osteoporosis have been observed. (1) The radial form, which involves only one or two rays of the hand or foot (two cases). (2) The zonal form in which the area of demineralisation is confined initially to such structures as one femoral condyle or one quadrant of a femoral head (six cases). These abnormalities developed one or two months after the onset of symptoms. Diagnostic detail was improved by tomography. Scintigraphy revealed an increased uptake of technetium-99m, not only in the demineralised area of bone but also—to a lesser degree—in the surrounding bone structures as well. Biopsy, performed in two cases, demonstrated diffuse osteoporosis alone. All the patients reported in this series became asymptomatic in approximately six months.