Diagnosis and treatment of idiopathic necrosis of the femoral head.

Fifteen cases, 27 hips, of idiopathic necrosis of the femoral head (INFH) were included in our series. The roles of radiography, isotopic bone scanning, intraosseous pressure measurement and intraosseous venography in the diagnosis of INFH were evaluated. Radiological examination could not reveal early cases, while isotopic bone scanning was more sensitive. There was an increase of intraosseous pressure in most of the diseased hips, and intraosseous venography showed abnormalities in all examined hips. The latter two tests could therefore detect early INFH. Core decompression was performed in 23 hips, 21 of which were followed for 7 to 27 months. Functional evaluation was good or excellent in 18 hips. Radiological re-examination remained unchanged in 19 hips. Postoperative intraosseous pressure measurement and intraosseous venography revealed a decrease of intraosseous pressure and improvement of venous drainage. Core decompression is therefore an ideal method of treatment for early INFH.