SLR - January 2016 - Ashley Bowles

Title: Preliminary Results of the Induced Membrane Technique for the Reconstruction of Large Bone Defects

Reference: Mansour TM, Ghanem IB. Preliminary Results of the Induced Membrane Technique for the Reconstruction of Large Bone Defects. J Pediatr Orthop. 2015 Oct 13.

Scientific Literature Review

Reviewed By: Ashley Bowles, DPM
Residency Program: Bethesda Health System

Podiatric Relevance: Large bone voids are often encountered in the lower extremity after bone resection secondary to infection, neoplasm or trauma. The most common methods for reconstruction of large bone defects are external fixation and vascularized fibula or rib grafts. These traditional methods for large bone defects are often challenging and lengthy procedures with potential donor site complications and residual deformities. In this article the authors present the induced membrane technique as an alternative therapy for reconstruction of large bone deficits in children.

Methods: This article presents the induced membrane technique for the treatment of lower extremity bone defects in eight children age 3 to 16 years with deficits ranging from 5 to 14cm. Three were congenital pseudarthroses of the fibula, one of the tibia, one Ewing sarcoma of the tibia, one of the ulna, one fibular osteosarcoma and onechronic diffuse tibial osteomyelitis.

The reconstruction technique described by Masquelet in 1986 is a two-staged approach. The first operation involves soft tissue and bony debridement with implantation of a polymethyl-methacrylate(PMMA) cement spacer to provoke a reaction to a foreign body at the site of bone defect. The limb is then stabilized with internal or external fixation and the soft tissue envelope carefully repaired. The second stage, occurring approximately six to eight weeks later, involves having the spacer removed and the defect filled with cancellous autologous bone graft. The biomembrane is then closed and the limb stabilized with internal fixation over the graft site.

Results: From 2006 to 2013, eight children underwent reconstruction for large bone defects with average follow-up of four years. Among the eightpatients, six healed uneventfully and two required revision with additional grafting or stronger internal fixation. Three cases used an autograft fibula to supplement cancellous graft but the authors recommend the use of a nonvascularized fibular graft and a locking plate when the bone defect is larger than 4 to 5cm. Histologic examination of the membrane showed clear osteoid activity and literature has show this membrane to be hypervascular and impermeable. This study had a mean interval of 60 days between the first and second surgeries. The authors believe the quality and stability of bone fixation is a key contributor in the success of this technique.

Conclusions: The delayed graft technique for significant bone loss after initial placement of a cement spacer serves as a viable alternative in complicated extremity reconstruction. The bioactivity of the membrane created around the cement spacer leads to an ideal environment for bone growth and remodeling. The authors advocate intramedullary nailing for short diaphyseal defects with cancellous grafts and plating with nonvascularized fibular graft and cancellous bone in larger defects.

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