ABSTRACT
Prefabricated osteomusculocutaneous flaps using free calvarial bone were examined
and evaluated in a rat model. The animals were divided into two groups according to
prefabrication time: 14 days in Group 1 (n = 10) and 28 days in Group 2 (n = 10).
Nine of 10 preparations demonstrated neovascularization in Group 1, and all flaps
showed neovascularization in Group 2. One flap was lost in Group 1 as a result of
infection. Each group was evaluated histopathologically before the second stage of
the experiment. Muscles without atrophy and osteocytes were noted in Group 1; however,
Group 2 animals had both muscle atrophy and nonviable bone. The prefabricated osteomusculocutaneous
flaps were then transferred as both island and free flaps. Flap viability was assessed
on postoperative day 7 by macroscopic observation. Although all flaps survived in
the island-flap group, two flaps failed to survive due to technical error in the free-flap
group. Neovascularization was clearly evident by 2 weeks in the osteomusculocutaneous
flaps; after 4 weeks, complete atrophy of the muscle meant that the flaps could no
longer be characterized as osteomusculocutaneous. Clinically, it might be possible
to use the outer table alone, in which case both thin skin and bone would be desirable.
This study may provide a model for this approach.
