Hemodynamics of the femoral head.

Scintimetry of hip joint tamponade in dogs

“…In earlier canine studies (Launder et al 1981, Lucht et al 1983) the blood flow to the femoral head epiphysis was promptly reduced when the intraarticular pressure was raised above the venous pressure. We found, however, that with scintimetry no signs of avascular necrosis could be demonstrated after 2 and 4 weeks.…”

“…No information was given about the arterial blood pressure of the investigated children, but presumably the highest intraarticular pressures must have been above the mean arterial blood pressure. In experimental studies (Tachdjian & Grana 1968, Borgsmiller et al 1980, Launder et al 1981, it has been shown that intraarticular pressures exceeding the mean arterial blood pressure are harmful to the blood supply of the femoral head. Woodhouse (1964) demonstrated the development of femoral head necrosis in puppies after 12 h of continual intraarticular tamponade at a pressure of 50 mm Hg.…”

“…The supine position with flexion-abduction of the hip was chosen to ensure the lowest possible intraosseous pressure (Krebs et al 1982) and a normal intraosseous blood flow (Launder et al 1981). The relationship between the intraarticular and the intraosseous pressure has been demonstrated by Lucht et al (1981).…”

“…Reports differ concerning the degree and duration of intraarticular pressure required to induce necrosis of the femoral capital epiphysis (Woodhouse 1964, Tachdjian & Grana 1968, Borgsmiller et al 1980, Launder et al 1981, Ganz et al 1981, Lucht et al 1983). These disagreements have stimulated further studies on the relationship between intraarticular pressure and the occurrence of femoral head necrosis.…”

Intraarticular pressure during operation of cervical hip fractures

“…The circulation of the femoral head is dependent on the intraarticular pressure being well below the diastolic blood pressure (Launder et al 1981, Drake & Meyers 1984, Tachdjian and Grana 1968. The intraarticular pressure, however, is dependent on the position of the hip; it is low in flexion and outward rotation and high in extension and inward rotation (Lloyd-Roberts 1953, Drake andMeyers 1984).…”