Abstract
Introduction:
20 cases of bone defect have been treated by the induced membrane technique avoiding allograft, microsurgery and amputation
Material and Methods:
9 cases of long bone defect (humerus and forearm) and 11 cases of bone defect at the hand have been included in this multicentre prospective study (3 centers). The aetiology in 11 cases was trauma, 7 cases were septic nonunions and 2 cases followed tumors. In the hand the bone loss was at least one phalanx, and for long bones the mean defect was 5 cm (3–11). All cases were treated by the induced membrane technique which consists in stable fixation, flap if necessary and in filling the void created by the bone defect by a cement spacer (PMMA). This technique needs a second stage procedure at the 2nd month where the cement is removed and the void is filled by cancellous bone. The key point of this induced membrane technique is to respect the foreign body membrane which appeared around the cement spacer and which creates a biologic chamber for the second procedure. Bone union was evaluated prospectively in each case by a surgeon not involved in the treatment, by X-ray and CT scan. Failure was defined as a nonunion at 1 year, or an uncontrolled sepsis at 1 month.
Results:
3 cases failed to achieve bone union, 2 in the hand and 1 in a long bone. No septic complications occurred and all septic cases healed. In 14 cases bone union was achieved with a delay of 5 months (1, 5–12). 2 biopsies allowed us to prove that osteoid tissue was created by the technique. At hand level all fingers have included. At shoulder and elbow level, function reached 75% of motion of the contralateral side.
Discussion:
Masquelet first reported 35 cases of large bone defect of tibia nonunion treated by the induced membrane technique which allow filling a bone defect with cancellous bone alone. The cement spacer induces a foreign body membrane (neo periosteum) which constitute a biological chamber. Animal models showed the properties of the membrane: secretion of growths factors (VEGF, TGFbéta1, BMP2) and osteoinductive activitie of the cells.
Conclusion:
This technique is useful in emergency or in septic condition where a bone defect cannot be solved by shortening. The technique avoids the use of microsurgery and the limit is the quantity of available cancellous bone.
