An apparatus to measure flexor tendon excursion and angular motion of the distal interphalangeal joint in a rabbit model.

Investigators evaluating flexor tendon adhesions have utilized visual, histological, and gross mechanical methods in reporting their results. We have developed a device to measure tendon excursion and distal interphalangeal joint motion for a small animal model. The device was tested for accuracy and reproducibility using the rabbit hindfoot. There was no statistical difference between the right and the left in 30 pairs of feet. This device provides an accurate method to quantify tendon excursion and relative adhesion formation in a rabbit model without destroying the specimen.

The stability of prostaglandin E1 in dilute physiological solutions at 37 degrees C.

The stability of prostaglandin E1 (PGE1) in three physiologic solutions was studied at body temperature (37 degrees C) over 32 days. The solutions were 100 mcg/ml PGE1 in isotonic saline (pH 4.5), 0.1 M phosphate buffered water (pH 7.4) or 0.01 M phosphate buffered isotonic saline (pH 4.7). PGE1 was found to be more stable in the saline and buffered saline solutions at the pH values of 4.5 and 4.7 respectively. Twenty-five per cent of the PGE1 remained at 32 days in these solutions while 95% of the PGE1 in the solution at pH 7.4 was degraded by day 14. The degradation of PGE1 in the acidic solutions appeared to be nearly linear when plotted on a semilog graph. This data allows one to use PGE1 in an aqueous, slightly acidic solution in a system that requires it to be kept at 37 degrees C for up to 30 days such as a biologically implantable pump. Investigators can use such a system in vivo to study the effect of known concentrations of PGE1 given over a period of time to a specific area of interest.