Intra-osseous pressure and oxygen tension in avascular necrosis

and osteoarthritis of the hip.

Kiaer-T; Pedersen-NW; Kristensen-KD; Starklint-H

J-Bone-Joint-Surg-Br. 1990 Nov; 72(6): 1023-30

AB: The intra-osseous pressure, PO2, and PCO2 were measured in 32 hips

(21 patients) which were painful but showed no severe degenerative

changes. Pre-operative scintigraphy and radiography was performed in

all patients. Thirteen hips showed early osteoarthritis, eight had

early osteonecrosis, and 11 had no changes. Core biopsies were

performed and the bone was examined histologically and graded for

necrosis. Histologically, necrosis was present in 27 specimens.

Scintigraphic findings did not correlate with the histological results

but were more closely related to the radiographic findings. The

intra-osseous pressure in hips with histological necrosis (mean 47

mmHg) was significantly higher than in hips without necrosis (mean 26

mmHg). The PO2 was lower in bone with histological necrosis (mean 44

mmHg) than in bone without (mean 71 mmHg). PO2 increased and

intra-osseous pressure decreased after decompression. The results

confirm that ischaemia plays a central role in the development of

necrotic changes in bone. Histological necrosis was found in hips with

radiographic signs of osteonecrosis and in those with osteoarthritis.

Radiography, and scintigraphy are shown to be insensitive methods for

differentiating between those disorders.