Treatment of Tibial Bone Defects with Free Flap, PMM-a Spacer, and Secondary Bone Grafting

Traumatic composite tissue loss of the tibia is a very severe problem, the solution of which usually poses significant problems to the reconstructive surgeon.

A series of 35 patients with traumatic composite bone defects of the tibia was reported. Thirty-four were males, with ages ranging from 18 to 68 years. The segmental bone defects were 4 to 9 cm.

The tibia was temporarily stabilized with an external fixator, the wound debrided, the fibula internally fixed when suitable, and the wound covered with a free flap. A solid spacer of polymethyl metacrylate (PMM) with gentamycin and vancomycin was placed in the bone defect. Four to 6 weeks later, the flap was reelevated, the spacer was withdrawn, and a tricortical iliac bone graft was used to reconstruct the defect. The external fixator was withdrawn and plate fixation of the tibia was performed, along with proximal and distal tibioperoneal synostosis.

The free flap success was 100%. The infection rate after the first stage was 0%. The infection rate after the second stage was 20%. Infection was suppressed with long-term antibiotics until fracture healing and hardware removal usually resolved it. In one case, the infection necessitated bone graft debridement, hardware removal, Ilizarov conversion, with eventual BK amputation.

Bone defects less than 10 cm long can be managed in a number of ways. A two-stage approach, using a solid cement spacer and a free flap, permits primary closing of the wound and prevents tissue collapse, allowing bone graft and hardware placement at a second stage. The procedure is safe and efficient. The infection rate after the second stage is significant, although it usually does not interfere with fracture healing.