Introduction: The induced membrane technique for the treatment of large bone defects is a two-step procedure. In the first operation, a foreign body membrane is induced around a spacer, then, in the second step, several weeks or months later, the spacer is removed and the Membrane pocket is filled with autologous bone material. Induction of a functional biological membrane might be avoided by initially using a biological membrane. In this study, the effect of a human acellular dermis (hADM, Epiflex, DIZG gGmbH) was evaluated for the treatment of a large (5 mm), plate-stabilised femoral bone defect.
Material and methods: In an established rat model, hADM was compared to the two-stage induced membrane technique and a bone defect without membrane cover. Syngeneous spongiosa from donor animals was used for defect filling in all groups. The group size in each case was n = 5, the induction time of the membrane was 3-4 weeks and the healing time after filling of the defect was 8 weeks.
Results: The ultimate loads were increased to levels comparable with native bone in both membrane groups (hADM: 63.2% ± 29.6% of the reference bone, p < 0.05 vs. no membrane, induced membrane: 52.1% ± 25.8% of the reference bone, p < 0.05 vs. no membrane) and were significantly higher than the control group without membrane (21.5%). The membrane groups were radiologically and histologically almost completely bridged by new bone formation, in contrast to the control Group where no closed osseous bridging could be observed.
Conclusion: The use of the human acellular dermis leads to equivalent healing results in comparison to the two-stage induced membrane technique. This could lead to a shortened therapy duration of large bone defects.
Keywords: Acellular dermis; Induced membrane technique; Masquelet technique.