Masquelet and Begue describe the two-stage induced membrane technique for reconstructing large long bone diaphyseal defects, in use since 1986. The paper presents the biological basis of the technique, a 35-case retrospective series, and a prospective 11-case series testing rhBMP-7 augmentation. The central question: can a PMMA-induced biological chamber reliably regenerate defects too large for conventional autograft?
For defects above 4–5 cm, plain autograft reliably fails due to resorption — even in a well-vascularized bed. Before the Masquelet technique, defects of this size required vascularized free fibula transfer or Ilizarov transport, both technically demanding and associated with significant morbidity.
When you encounter a segmental tibial defect after debridement of an infected nonunion, the decision framework is: Stage 1 places a PMMA spacer (6–8 week interval); Stage 2 fills the membrane with morcellized cancellous autograft, leaving the membrane intact. The membrane must not be excised. The sheep data show resorption in 100% of cases when it is removed.
For defects up to 15–20 cm, harvest from all four iliac crests. If autograft is insufficient, bone substitute at ≤1:3 ratio is acceptable without compromising outcomes.
Do not add rhBMP-7 to the graft: the prospective data show worse outcomes, likely because the membrane already concentrates BMP-2 locally, and exogenous addition may create supraphysiologic concentrations that inhibit osteoblast activity.
Masquelet and Begue describe the two-stage induced membrane technique for reconstructing large long bone diaphyseal defects, in use since 1986. The paper presents the biological basis of the technique, a 35-case retrospective series, and a prospective 11-case series testing rhBMP-7 augmentation. The central question: can a PMMA-induced biological chamber reliably regenerate defects too large for conventional autograft?
For defects above 4–5 cm, plain autograft reliably fails due to resorption — even in a well-vascularized bed. Before the Masquelet technique, defects of this size required vascularized free fibula transfer or Ilizarov transport, both technically demanding and associated with significant morbidity.
When you encounter a segmental tibial defect after debridement of an infected nonunion, the decision framework is: Stage 1 places a PMMA spacer (6–8 week interval); Stage 2 fills the membrane with morcellized cancellous autograft, leaving the membrane intact. The membrane must not be excised. The sheep data show resorption in 100% of cases when it is removed.
For defects up to 15–20 cm, harvest from all four iliac crests. If autograft is insufficient, bone substitute at ≤1:3 ratio is acceptable without compromising outcomes.
Do not add rhBMP-7 to the graft: the prospective data show worse outcomes, likely because the membrane already concentrates BMP-2 locally, and exogenous addition may create supraphysiologic concentrations that inhibit osteoblast activity.