PURPOSE OF THE STUDY

The surgical treatment of proximal tibia fractures requires a reduction and fixation of the split condyle, elevation of the depressed interfragment of articular surface. The golden standard is the application of autogenous bone grafts for filling in the defect in the cancellous bone of the tibial condyle. Bioactive glass-ceramics material may be successfully used for the filling. Gass-ceramics BAS-O is biocompatible and bioactive and has also suitable mechanical properties and therefore it was used in combination with autogenous bone marrow in order to speed up osteogenesis.

MATERIAL

The study covered 12 patients, 4 men and 8 women, with a fracture of the proximal tibia classified according to AO as type B3.1, B3.2 and C3.2. The average follow-up period was 5.5 years (range, 2 to 8 years).

METHOD

After the assessment of the type of fracture and revision of soft tissues the depressed interfragment of articular surface was elevated and the defect was completely filled with BAS-O granules in combination with 10 ml of autogenous bone marrow. The broken condyle was fixed by screws or buttress plate. During the first year the process of healing was checked by radiographs at 3-month intervals. All 12 patients were invited for a follow-up examination where the radiograph of the proximal tibia was assessed in two projections and the clinical condition was evaluated using Rasmussen criteria.

RESULTS

According to the Rasmussen criteria 12 patients achieved the value of 21-29 points with the average of 26.4 of 30 possible points. The volume of the BAS-O filling was 7.1-44.3 ccm and did not change throughout the whole period of the follow-up. The depression of an interfragment of articular surface prior to operation was 3-17 mm, average 6.3 mm. The residual depression after the operation was 0-4 mm, average 1.7 mm. No symptoms of loosening, extrusion or surrounding of the BAS-O material by fibrous tissue was found. The integration with the surrounding bone occurred during the first 3 months.

DISCUSSION

The bioactive coral hydroxyapatite has been successfully used to fill similar defects by a number of authors. Among the benefits of BAS-O granular system is an easy handling and a fast integration with the bone tissue of the recipient due to the development of a hydroxyapatite layer on its surface after the contact with tissue fluid. Autologous bone marrow was added to the system in order to initiate osteogenesis and a faster healing of the defect. The mentioned material is suitable also from the mechanical viewpoint as neither deformation nor resorption was found in the followed-up patients. We reduced the surgery duration and morbidity and improved the patients comfort.

CONCLUSIONS

Part of the surgical management of the fracture of the tibial plateau with a depressed segment of subchondral bone is its elevation. For filling in of the traumatic defect in the cancellous bone of the proximal tibia the bioactive, glass-ceramics, granular material BAS-O may be successfully used. Mechanical and chemical properties (compression strength, non-resorption) ensure its stable position in the filling as well as a constant volume. Osteointegration was accelerated by adding 10 ml of autologous bone marrow. The use of the glass-ceramics material reduces the surgery duration, improves the patient's comfort and decreases the probability of incidence of complications.