Effectiveness of free gracilis muscle flaps in the treatment of chronic osteomyelitis with purulent fistulas at the distal third of the tibia in children.

BACKGROUND: Chronic purulent infection at the distal third of the tibia resulting from of a previous hematogenous osteomyelitis in children is a severe infection which is seldom reported in the literature and remains a difficult challenge for orthopaedic surgeons. METHODS: A 6-year retrospective review from September 2001 to October 2006 (institutional review board-approved) was performed to evaluate postoperative surgical results of this type of infection using a free gracilis muscle flap. RESULTS: A total of 6 children with an average age of 9.8 years were included. The infective period of purulent fistulas ranged from 6 to 31 months (mean 17.7). Staphylococcus aureus were reported in all wounds (6/6) and were commonly combined with Escherichia coli (5/6). All of the free gracilis muscle transfers were successful (6/6 flaps). No postoperative recurrence of infection was observed with an average postoperative follow-up period of 3 years. All patients were also able to satisfactorily demonstrate walking and standing functions. CONCLUSIONS: Both the radical debridement of infected tissues and restoration of ample blood supply using free muscle flaps are the keys to success. Based on its favorable form, the free gracilis muscle flap can be considered a suitable muscle for use in reconstruction. LEVEL OF EVIDENCE: IV.

Neovascularization and free microsurgical transfer of in vitro cartilage-engineered constructs.

Cartilage tissue engineering shows to have tremendous potential for the reconstruction of three-dimensional cartilage defects. To ensure survival, shape, and function, in vitro cartilage-engineered constructs must be revascularized. This article presents an effective method for neovascularization and free microsurgical transfer of these in vitro constructs. Twelve female Chinchilla Bastard rabbits were used. Cartilage-engineered constructs were created by isolating chondrocytes from auricular biopsies, amplifying in monolayer culture, and then seeding them onto polycaprolactone scaffolds. In each prefabricated skin flap, three in vitro cartilage-engineered constructs (2 x 2 x 0.5 cm) and one construct without cells (served as the control) were implanted beneath an 8 x 15 cm random-pattern skin flap, neovascularized by implantation of an arteriovenous vascular pedicle with maximal blood flow. Six weeks later, the neovascularized flaps with embedded cartilage-engineered constructs were completely removed based on the newly implanted vascular pedicle, and then freely retransferred into position using microsurgery. Macroscopic observation, selective microangiography, histology, and immunohistochemistry were performed to determine the construct vitality, neovascularization, and new cartilage formation. The results showed that all neovascularized skin flaps with embedded constructs were successfully free-transferred as free flaps. The implanted constructs were well integrated and protected within the flap. All constructs were well neovascularized and showed histologically stability in both size and form. Immunohistology showed the existence of cartilage-like tissue with extracellular matrix neosynthesis.