[Future of bone allografts in massive bone resection for tumor]. / Avenir des allogreffes osseuses dans les résections osseuses massives pour tumeur.

Currently cryopreservation offers the best means of preserving bone tissue for allografts. At -196 degrees C all enzyme activity is halted and tissue preservation is unlimited. Perfect sterilization, adapted cryoprotection and controlled freezing and thawing are now part of the well-controlled process of bone preservation in bone banks. At implantation, the mechanical properties of cryopreserved bone is as good as or better than fresh bone, although the diaphyseal cortical bone is more fragile. Anatomic and physiologic reconstruction of the graft area is a major factor in graft resistance. It takes approximately three weeks for vessels to penetrate cancellous allografts and at least one month for total revascularization. The delay may reach several years for cortical bone. The immune response of the host is determined by the antigenic properties of the leukocytes in the bone marrow as well as the blood vessels and nerves. The protein-mineral complex itself has little antigenic effect. A certain number of non-specific immune reactions result from transfusions almost always performed with bone grafting. At the present time, there is no artificial material capable of providing a mechanically acceptable substitute for allograft bone in limb reconstruction. Allograft bone currently stocked in bone banks provides a biologically and clinically acceptable means of reconstruction after major bone loss. Other factors such as public acceptance and administrative authorizations will also play an important role in the future of massive reconstruction with bone allografts.

[Assessment of activity in bone tumours by telethermography (author's transl)]. / Surveillance téléthermographique des tumeurs osseuses irradiées.

The assessment of activity in bone tumours after irradiation is somewhat uncertain. In most cases, the process of healing cannot be assessed. The authors propose the use of tele-thermography, which was used 14 patients. In 8 cases, amputation was performed when tele-thermography showed persistent activity. In all cases, secondary microscopic examination of the amputated limb showed remaining active tumour in spite of negative radiological appearances. In 6 cases, in which tele-thermography was negative, the limb was not amputated with no recurrence up to the present time. The follow up study has varied from 15 months to 5 years. The authors consider that this technique is of great value in the assessment of the activity of irradiated sarcomata.

[Fractures of the shaft of the humerus: systematic plate fixation. Anatomic and functional results in 156 cases and a review of the literature]. / Fractures diaphysaires de l'humérus : ostéosynthèse systématique par plaque. Résultats anatomiques et fonctionnels d'une série de 156 cas et revue de la littérature]

PURPOSE OF THE STUDY: Based on our experience with plate fixation of humeral shaft fractures and an analysis of the international literature, we attempted to answer the following questions. What functional outcome and what complications can be expected after surgery? Are the classical complications of open fracture surgery (screw fixation, wiring, plate fixation without compression.) as frequent after plate fixation using the Müller technique? MATERIAL AND METHODS: We reviewed our series of 156 humeral shaft fractures (61 p. 100 men, mean age 45 years) including 21 cases of multiple trauma and 24 multiple fractures. A floating elbow was present in 8 cases and skin opening in 16. Initial radial deficiency was observed in 28 cases. Plate fixation was the only method used for the humeral shaft fractures. We used the modified Stewart and Hundley classification. RESULTS: Postoperative paralysis occurred in 8 cases (5.1 p. 100, 5 complete paralysis); only one patient suffered persistent severe sequelae. There were also 8 malunions and 3 late consolidations. Consolidation rate was 94.2 p. 100, sepsis rate was 1.5 p. 100. Good or very good outcome was achieved in 86.6 p. 100 of the cases. DISCUSSION: In the literature, (71 series, 5 000 patients), plate fixation of humeral shaft fractures has given very good functional results with few initial failures, malunions or cases of sepsis. Radial paralysis is cited as a complication in 6.5 p. 100 of all plate fixations but is reversible in 90 p. 100 of cases. Classical orthopedic methods and centromedullar techniques produce more stiffness. The Sarmiento cuff can give good results after rigorous patient selection. CONCLUSION: Plate fixation according to the Müller technique is a reliable osteosynthesis method with few initial failures or malunions as evidenced by data in the literature. Infection is also rare. Although the radial nerve risk makes this technique rather difficult, excellent functional results can be achieved.

[Secondary internal osteosynthesis after external fixation for recent or old open fracture of the lower limb]. / Ostéosynthèse interne secondaire après fixation externe pour fracture ouverte, récente ou ancienne, du membre inférieur.

PURPOSE: The purpose of our study is to analyse the indications, results and limits of secondary internal fixation after external fixation for open fracture of the lower limb. MATERIAL: Our series covered 21 patients treated between 1991 and 1994. There were 17 men and 4 women. Tibia was affected 17 times and femur 5 times (one bifocal fracture). In Gustilo's classification, we had 1 case of type 1, 12 of type II and 8 of type III. METHODS: We used 15 times the FESSA External Fixator and 6 times a monotube external fixator in emergency. We have done secondary 11 intra medullary nailing and 11 patients were treated by plating (one patient had both) 13 patients had a bone graft (cortico-cancellous graft). In the first group of patients (10 cases), the initial treatment gave us good results for both skin and bone healing. The external fixation was replaced by an internal one in order to accelerate bone consolidation and to allow an early weight-bearing. Removal of the external fixation was made at an average of 4 months postoperative. In the Second group (11 cases) the internal fixation was proposed because of an insufficiency of the external fixation leading to complications as: non union, mal union and bone defects. External fixation was removed in a mean time of 8 months. Internal fixation was completed by local bone autograft. RESULTS: 17 patients have been reviewed. Consolidation occurred with an average of 6 months after internal fixation 1 to 24 months. We had no deep infection but only 2 superficial ones. DISCUSSION: We chose 2 types of indication, and we called them programmed and for necessity. The first group of 10 patients whose stain was moderate and whose initial setting up had permitted a perfect anatomic reduction with a rapid wound healing. Internal fixation was performed after a short duration of external fixator. An early weight bearing was allowed so that the functional recovery could be obtained quickly. The second group is represented by patients whose internal fixation was done for non union, malunion or bone defect. In such a case autogenous cancellous graft was used to fill the defect.

[Bone biomaterial]. / L'os biomatériau.

The use of deep frozen allografts is not a recent technic. The evolution of the conservative technics authorize a sufficient preservation of osseous and cartilaginous structure. The clinical results are considered as good in most of the cases. The intra medullary cells are most involved in immunological responses but clinically speaking only 10% to 20% of the case treated has a reject. The becoming of the grafted tissue is best if the recipient is young, the graft well fixed and the muscular surrounding well vascularized. 454 grafts and 64 massive osteochondral allografts have been archived between 1979 and 1993 for traumatic, tumoral, and surgical diseases. The results have been considered as good or excellent in 85% of the cases. The actual problems are the biomechanical behaviour of the ligamentary revascularization and fixation which gives in numerous cases a high percentage of loosening.

[Reconstruction of the acetabulum after iterative surgery of the hip (report of 38 cases)]. / Les reconstructions de cotyle après chirurgie itérative de la hanche (à propos de 37 cas).

UNLABELLED: The hip revision surgery like oncology surgery may need massive allografts to rebuilt the acetabulum or an hemi pelvis. Since 1982 we have chosen to use deep frozen massive allografts instead of massive metallic prosthesis, resection, or osteosynthesis of the femur to the iliac bone or the sacrum. These last proposal seems for our patients too heavy, the functional results being always bad. PATIENTS AND METHODS: --37 Acetabulum reconstruction has been performed. (18 hemi-pelvis). --The follow-up is from 1 to 12 years with a medical of 5 years and 2 months. --The tumoral pathology (14 cases) was for 50% chondrosarcomas [7]. 6 infections (1 massive echinococcosis and 5 osteomyelitis) --17 hip reconstruction for revision surgery. We use deep frozen allografts cryopreserved with Dimethylsulfoxide 10%. No secondary irradiation. The allografts were used after securisation (after the 6th month after the procurement). Most for the time we used 2 platres, one posterior outside the pelvis, one anterior inside the pelvis. Screwed on the contralateral pubis bone and the sacrum. A hip prosthesis was used in almost all the cases. In tumoral cases, the results were excellent with chondrosarcomas but in the other cases metastasis and death were usually seen in the 2 or 3 years following the surgery. --3 instability of the prosthesis. --2 fractures of the allograft. In the non tumoral cases, the integration of the graft was excellent. --1 instability of the prosthesis needed a antiluxent crescent. --1 fracture of the graft needed adjonction of autografts and new osteosynthesis. --1 superficial infection. Good functional results has been obtained with the use of massive allografts. The fracture of the allografts can heal without a new operation. In some cases we have had some liquid surrounding the grafts which can be a immunological response.

[Spontaneous perforation of the hepatic duct during biliary lithiasis complicated by acute pancreatitis]. / Perforation spontanée du canal hépatique au cours d'une lithiase biliare compliquée de pancréatite aiguë

The association of perforation of the common bile duct, cholecystitis and acute pancreatitis, should be emphasized. Physiopathology of perforation of the bile duct may be compared with that of pancreatitis. Repair of the bile duct may be delicate requiring hepatico-jejunostomy on an isolated loop.

[Massive reconstruction of acetabulum and proximal femur]. / Reconstructions massives du cotyle et du fémur proximal.

In revision hip surgery, allografts are useful for restoring the bone stock and allow the muscle fixation avoiding the use of massive metallic prothesis. MATERIAL AND METHODS: We have reviewed 51 hip reconstructions with a follow up of 4 years and half (1982 - 1991). Indications were: - revision arthroplasties with destroyed acetabulum, - bone tumors (mainly chondrosarcoma). RESULTS: The results are good for pain, articular movement and the consolidation of the allograft host bone junction. Some complications were encountered: - Post-operative death (early or late for tumoral extension) in case of major surgery for tumor (4 cases). - Deep infections (2 cases). - Weakness of the gluteus medius with hip dislocation needing anti-dislocation device. - Aseptic serous fluid leak meaning immunobiologic reaction of bone grafts (3 cases). DISCUSSION: This surgery has to be compared to massive reconstruction prostheses, arthrodesis with limb shortening, femoral head and neck resection and in some cases inter ilio-abdominal amputation which gives also major post-operative complication.

[Use of allografts in oncology and traumatology]. / Utilisation des allogreffes en oncologie et en traumatologie.

Fresh allografts of bone are commonly used for repairing small defects, but preserved grafts are required for replacing large sections of long bones. We have collected these grafts in sterile conditions and then preserved the specimens in liquid nitrogen at minus 196 degrees Celsius. Biological, histological and biomechanical studies have confirmed the value of this technique. The method preserves the normal architecture of bone and viable cartilage cells. The medullary cells are gradually destroyed in situ leaving a protein matrix to which mineral components are fixed. Neither of these are antigenic in allografts and immunological problems are rarely encountered. When the recipient site is well vascularised the graft becomes fully integrated within two or three years. Doubt has been expressed as to the functional viability of the cartilage in large allograft joint replacements, and is has been suggested that metal prostheses might be better. Research is in progress in the use of ligament allografts and on the use of bank bone with large prostheses. The functional results are satisfactory in more than 90% of patients treated with these large allografts.

[Analysis of stress in the knee using the finite element method]. / Analyse des contraintes dans le genou par la méthode des éléments finis.

The increase in the number of the studies of the stress around the anatomic prosthesis by the finite element method incited the authors' work. Our purpose was to study the methodology of a technic with simple cases. The finite element method is a method of calculation which allow the calculation of the displacement under the stresses of each element that we created in the structure. Before this calculation, we needed to define the exact geometry of the structure, the elementary properties of the material and the conditions of the experimentation, particularly the strains that exist in the structure. Three simple examples are given: an osteosynthesis plate with an hole, a knee model that Maquet studied with the photoelasticimetry method and a bidimensional knee model. The results are traduced by different colours or by coloured ligns. The conclusion is to warn the orthopaedic surgeons to look carefully what model is behind the pretty coloured results.