The exact mechanism by which flexor tendons heal after injury is still not completely clear. Understanding the response of tendon to injury and repair is important to the practicing surgeon who seeks better clinical results. This stuty was intended to determine the course of tendon healing and the gain of tensile strength in the circumstance of normal conditions.
Materials and Methods
Flexor tendons on both lower extermities were divided and repaired with mersilene 4-0 in rabbits and after 2,4,6,8, weeks we obtained the pieces of tendons and have studied the histologic changes and measured tensile strength as time passed.
Results
Histologically fibrobalst-like cells were proliferated on the epitenon and migrated into the suture site and produced collagen fibers in the central area. Tensile strength was proportionately increased until 8 weeks and well correlated with histologic findings.
In conclusion, healing of the repaired tendon was initiated on the surface area and gained tensile strength with time passed.
Reports suggesting that the tendon itself could play is a significant part in the repair process without provision of microcirculation. To investigate the importance of nutritive environment in the healing of reconstructed tendons, the morphology of sutured free tendons in the synovial fluid of the knee joint, without resstablishment of micrecirculation,was studied in rabbits.
Material and Methods
The strip of flexor tendon was harvested and divided 2 pieces and repaired with interrupted suture. The knee joit then opened medially through a small incision and repaired tendon strip was transplanted into the open knee joint. After 2 weeks(n=10), 4 weeks(n=10), 6 weeks(n=10) and 8 weeks(n=10), the sutured tendon was removed from the joint and examined histology and measured tensile strength.
Results
Mactoscopically the surface of all piece was smooth and glistening. Fibroblasts were appeared in the sutured gap and produced collagen fiber and after 6 weeks many portions of collagen fibers were maturated. The gain of tensile strength was proportional to the time till 8 weeks.
The findings indicate that diffusion of nutrients may be important for the survival and reconstresstablishment of the microcirculation.