In a shearing type
of muscle injury, scar formation prevents restoration of myofiber
continuity and the transected myofibers may become permanently divided
into two separate myofibers. We have analysed whether the injured
myofiber stumps can fuse and continuity of the transected fibers be
re-established, if the stumps are surgically closely apposed immediately
after injury. 55 rat soleus muscles were transected, after which the
epimysium was carefully sutured and the leg was immobilised for seven
days. The animals were sacrificed at 2, 5, 7, 10, 14 and 25 days after
surgery. All muscles were analysed by light and electron microscopy as
well as by immunohistochemistry. Mechanical strength was also measured
at day 10 and 25. We observed that suturing reduced the extent of the
intervening scar and accelerated healing. More importantly our results
indicate that fusion of the stumps and thus restoration of myofiber
continuity, is possible after myofiber transection injury.