The effect of vascularization on avian flexor tendon repair. A biochemical study.

Although it has been demonstrated in experimental animals that vascular perfusion functions less effectively than diffusion as a nutrient pathway to the uninjured flexor tendon, it is recognized that the nutritional requirements of an injured flexor tendon may be different. The present study examines several biochemical parameters of avian flexor tendon repair, during a six-week period, in the presence of an intact vinculum longum and with the vinculum longum ligated. Formation of collagen/noncollagen protein, glycosaminoglycan synthesis, and tissue levels of both DNA and hexosamine were quantified. The absence of the vincular blood supply did not affect the levels of total DNA and hexosamine, did not alter the pattern of either protein or glycosaminoglycan formation in the early healing phase, and did not impair the overall synthesis of collagen and noncollagen protein throughout the six-week study period. However, the pattern of collagen and noncollagen protein synthesis differed in lacerated tendons during the period of repair; noncollagen protein synthesis peaked at ten days, while collagen synthesis increased uniformly throughout the 42-day period of study. There was a notable decrease in total matrix hydroxyproline (collagen) during repair, which continued throughout the entire first three weeks after laceration. Thus, the actual percentage of collagen synthesis decreased during the first three weeks of repair and began to return to its normal uninjured level by the sixth week.(ABSTRACT TRUNCATED AT 250 WORDS)