Previous clinical studies have shown the efficacy of a foreign body-induced membrane combined with bone autograft for the reconstruction of traumatologic or pathologic large bone defects or, bone non union. This membrane, rich in mesenchymal stromal cells (MSC), avoids bone autograft resorption and promotes consolidation by revascularisation of the bone and secretion of growth factors. Reconstruction requires two different surgical stages: firstly, insertion of a cement spacer in the defect, and secondly, removal of the spacer, preservation of the foreign body-induced membrane and filling of the cavity by bone autograft. The optimal time to perform the second surgical stage remains unclear.

So, we aimed to correlate bone healing and, phenotype and function of cells isolated from the induced membrane, in patients whose second surgery was performed on average after 6 months (i.e. beyond the recommended time of one month). Cell phenotype was determined by flow cytometry and cell function by: alkaline Phosphatase enzyme activity, secretion of calcium and von Kossa staining. Second, using histological and immunohistochemistry studies, we aimed to determine the nature and function of induced membrane over time. Seven patients were included with their consent.

Results showed Treated patients achieved in all cases bone union (except for one patient) and in in vitro and histology and immunohistochemistry gave some indications which need to be completed in the future. First, patient age seemed to be an indicator of bone union speed and recurrent infection, appeared to influence in vitro MSC osteogenic potential and induced membrane structure. Second, we reported, in bone repair situation, the commitment over time in osteogenic lineage of a surprising multipotent tissue (induced membrane) able of vascularisation/ osteogenesis/ chondrogenesis at a precocious time. Finally, best time to perform the second stage (one month) could be easily exceeded since bone union occurred even at very late times.

Summary

Human amniotic membrane has interesting properties for regenerative medicine. To use it as an Advanced Therapeutic Medicinal Product in bone surgery, we are evaluating: the necessity of its osteodifferentiation and the impact on immunogenicity; its optimal condition for storage.

Introduction: The aim of the study is to assess the complication rate in lengthening of the femur and to analyze the main factors inducing complications.

Materials & method: A retrospective study of 151 cases of lengthening with different methods (External Fixator of Judet 9, Callotasy with Orthofix :89, Ilizarov 9, External Fixator of Wagner 9, Lengthening Albizzia Nail 29) was investigated. The mean age was 13, 21 years (ET : 4,82, max : 38, min : 4). The aetiologies of femoral length discrepancy were congenital in 85 cases, post traumatic in 30, Post infectious in 22 and neurologic in 13 cases. One girl had Still’s Disease. The mean elongation was 55,17mm (ET : 17,3, Max ; 130, min : 20) except with the Ilizarov method with a mean lengthening of 91,8 mm. The mean percentage of elongation was 21 %

Classification of the Complications was in three grades :

- I : Benign complication without any unexpected surgery or anaesthesia

The complications were recorded in four periods: surgery, elongation, consolidation and late complications

Results: There were 151 complications (78 Grade I, 59 grade III, 14 grade III). There were only three complications during first surgical procedure, 95 during elongation 49 during consolidation and 4 late complications. Analysis of the different pathologies shows that the rate of complications is the same for each etiology (around 100%) but the rate of complications of grade 2 and 3 shows a significant difference with a higher rate for neurological and congenital aetiologies. Benign complications are found in the post infection group. Analysis of the different methods used shows the same rate of complications in benign conditions except for the Albizzia Nail with a significant lower rate. Complications of grade 2 are seen in the ancient Judet method and in the Albizzia Nail due to the multiple general anaesthesia . Complications of grade 3 are seen in the Wagner method due to a high rate of congenital pathology and to a mean lengthening of 35 % of femoral initial length.

Articular complications do not show any significant difference between the different methods. The main complications are seen in neurological and post infectious diseases. The mean percentage of lengthening in these complications is not different of the mean percentage of the series.

Conclusion: Lengthening of the femur is still a difficult problem with a mean rate of complications of 100 % The type of method used is not the main determinant in the appearance of these complications. We want to emphazise the difficulties in performing lengthenings in neurological and congenital pathologies.

We present an original method for the treatment of neglected Monteggia fractures using the Ilizarov technique. This method allows reduction without accessing the radial head by progressive ulnar lengthening after proximal subperiosteal osteotomy of the ulnar bone. We used this method in a six and a half year old girl and achieved excellent radiographical and functional results with normal joint amplitudes. In our opinion, the quality of the outcome is related to the progressiveness of the bone lengthening enabled by this technique which allows restoration of the ulnar length, preservation of the axes of both forearm bones, and controlled reduction of the radial head.