L'analyse de 70 cas d'ostéotomie tibiale de valgisation par addition médiale d'un coin de phosphate tricalcique de synthèse β (β TCP) (Biosorb^®) avec un recul moyen de 18 mois a montré la bonne tolérance clinique, biologique et radiologique de ce biomatériau.

La correction obtenue, malgré une légère perte angulaire était excellente dans 80,5 % des cas. La tolérance du matériel d'ostéosynthèse en position sous-cutanée était moyenne puisque nous avons constaté 1 infection et 12 cas d'agrafe douloureuse nécessitant l'ablation du matériel 8 fois.

La consolidation de l'ostéotomie était acquise dans 98,5 % des cas autour du 3^e mois. L'ostéo-intégration était bonne dans 96 % des cas. La résorption était complète et rapide lorsque le substitut était sous forme de granulés en zone spongieuse, elle était partielle pour un substitut sous forme de coin massif.

We report our experience with a β tricalcium phosphate ceramic to fill open-wedge tibial osteotomy gaps.

Seventy high tibial open-wedge osteotomies were performed in 70 patients (47 men and 23 women). Ostotomy was performed for osteoarthritis in 56 knees, Ahlback classification stage I (n = 18), stage II (n = 32), stage III (n = 6) and for congenital varus in 14. Mean patient age was 45.2 years (16-69). We used a wedge-shaped piece of ceramic with an appropriate angle, which was associated with granulated material to complete the gap filling for the last 20 cases. One or two staples were used for fixation. Clinical and radiological outcome was assessed at 6 weeks, 3 months, 6 months, and at last follow-up. Mean follow-up was 18 months.

There were no biological or clinical complications related to biomaterial intolerance. Tolerance to the osteosynthesis material was mediocre since we observed one infection and 12 cases of pain related to the staples which required material removal in 8 patients. Bone healing was achieved in 98.5%. Final correction was between 3° and 6° valgus in 80.5%. There was a loss of correction angle between the postoperative film and the bone healing film. Factors related to sustained correction were: non-fractured wedge, intact lateral tibial cortical, osteosynthesis with two staples. Osteointegration was good and rapid in 96%. We found two complete lucent lines at last follow-up but with variable resorption depending on the shape of the bone substitute.

Use of a ceramic wedge to fill high tibial medial open-wedge osteotomy gap is a reliable reproducible technique providing correction without formation of a malalignment callus. Bone healing is achieved in 98.5% of the cases at about three months. Osteointegration is good in 96%. Resorption is complete and rapid when the substitute is implanted in granular form in a cancellous zone and is partial and slow when implanted as a massive wedge.