VASCULAR VOLUME DETERMINATION OF ARTICULAR TISSUES IN NORMAL AND ANTERIOR CRUCIATE LIGAMENT-DEFICIENT RABBIT KNEES

The vasculature of diarthroidal joints has been well documented; howev er, the volume of vessels supplying different articular tissues is unk nown. Angiogenesis, the formation of new vessels from preexisting ones , is difficult to quantify in joints due to the unavailability of a su itable technique. Although angiogenesis is known to occur in rheumatoi d arthritis, the development of new vessels following joint injury has not been ascertained. A vascular easting technique was developed usin g carmine red dye to measure the vascular volume of the medial collate ral ligament (MCL), lateral collateral ligament (LCL), menisci, medial capsule, and infrapatellar fat pad of the rabbit knee joint. Vascular volume determinations were repeated at 4 weeks in a group of anterior cruciate ligament (ACL)-transected animals and in a sham-operated con trol group. The volume of vessels supplying the MCL was estimated to b e 0.22 +/- 0.07 mu l (mean +/- S.E.M.), the LCL volume was 0.25 +/- 0. 05 pi, the medial meniscus volume was 0.19 +/- 0.03 mu l, the lateral meniscus volume was 0.40 +/- 0.08 mu l, the medial capsule volume was 0.14 +/- 0.05 mu l, and the infrapatellar fat pad volume was 1.90 +/- 0.62 mu l. Following ACL transection, angiogenesis was found to occur in the MCL only. All other tissue vascularities were not significantly different from sham-operated controls. A quantifiable method for meas uring vascular volume of knee joint tissues has been described. Joint instability stimulates angiogenesis in the ipsilateral MCL; however, t he absence of angiogenic activity in other articular tissues might hel p explain the lack of posttraumatic healing associated with these join ts. (C) 1998 Wiley-Liss, Inc.