Abstract
1. Experiments were performed to measure the partial pressure of oxygen in the synovial fluid (Ps,O2) of the normal rabbit knee joint and assess the extent to which this varied with changes in knee joint blood flow. 2. With the hypodermic needle oxygen electrode sited just within the synovial cavity, Ps,O2 values ranged from 25 to 72 mmHg with a mean of 48.2 +/- 3.1 (S.E.M.; n = 18). 3. Ps,O2 was found to decrease with increasing depth of penetration of the oxygen electrode. Lowest values were observed close to the articular cartilage. 4. Electrical stimulation of the posterior articular nerve (PAN) of the knee resulted in vasoconstriction of knee joint blood vessels which was accompanied by a decrease in Ps,O2. The frequency-response and voltage-response profiles to electrical stimulation of PAN, although differing in magnitude, showed a high degree of correlation between blood flow and Ps,O2. 5. As judged by the conduction velocity, the vasoconstrictor response to nerve stimulation was mediated by unmyelinated nerve fibres, presumed to be sympathetic postganglionic fibres. 6. In view of the low Ps,O2 values occurring deep within the joint, avascular structures such as cartilage could be subject to injury if sustained reduction in synovial blood flow occurred. This could be a contributory factor in the pathogenesis of degenerative and inflammatory joint diseases.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.