Die Anwendung des injizierbaren Knochenzements Norian�SRS bei Tibiakopffrakturen

Radiographic and Histological Analysis of a Synthetic Bone Graft Substitute Eluting Gentamicin in the Treatment of Chronic Osteomyelitis

Introduction: Managing chronic osteomyelitis can be challenging and attention to the osseous dead-space left following resection is an important part of successful treatment. We assess radiographic bone healing following implantation of a gentamicin-eluting synthetic bone graft substitute (gBGS) used at chronic osteomyelitis (cOM) resection. We also describe histological carrier changes from biopsies in nine cases at various time points. Methods: This was a retrospective review of a prospectively collected consecutive series of 163 patients with Cierny-Mader Type III or IV cOM who underwent single-stage excision, insertion of gBGS and definitive soft-tissue closure or coverage. Bone defect filling was assessed radiographically using serial radiographs. Nine patients had subsequent surgery, not related to infection recurrence, allowing opportunistic biopsy between 19 days and two years after implantation. Results: Infection was eradicated in 95.7% with a single procedure. 138 patients had adequate radiographs for assessment with minimum one-year follow-up (mean 1.7 years, range 1.0-4.7 years). Mean void-filling at final follow-up was 73.8%. There was significantly higher void-filling in metaphyseal compared to diaphyseal voids (mean 79.0% versus 65.6%; p=0.017) and in cases with good initial interdigitation of the carrier (mean 77.3% versus 68.7%; p=0.021). Bone formation continued for more than two years in almost two-thirds of patients studied (24/38; 63.2%). Histology revealed active biomaterial remodelling. It was osteoconductive with osteoblast recruitment, leading to the formation of osteoid, then woven and lamellar bone on the substrate's surface. Immunohistochemistry demonstrated osteocyte specific markers, dentine matrix protein-1 and podoplanin within the newly formed bone. Conclusion: This antibiotic-loaded biomaterial is effective in managing dead-space in surgically treated cOM with a low infection recurrence rate (4.3%) and good mean bone void-filling (73.8%). The radiographic resolution of the bone defect is associated with bone formation, as supported by histological analysis.

Autograft transfer from the ipsilateral femoral condyle in depressed tibial plateau fractures

Introduction :

The rationale for operative treatment of depressed tibial plateau fractures is anatomic reduction, stable fixation and grafting. Grafting options include autogenous bone graft or bone substitutes.

Methods :

The autograft group included 18 patients with depressed tibial plateau fractures treated with autogenous bone grafting from the ipsilateral femoral condyle following open reduction and internal fixation. According to Schatzker classification, there were 9 type II, 4 type III, 2 type IV and 3 type V lesions. The average time to union and the hospital charges were compared with the bone substitute group. The latter included 17 patients who had an excellent outcome following treatment of split and/or depressed lateral plateau fractures, using a similar surgical technique but grafting with bone substitutes (allografts).

Results :

Excellent clinical and radiological results were detected in the autograft group after an average follow-up of 28 months (range 12-37). The average time to union in the autograft group was 14 weeks (range 12-16), while in the bone substitute group it was 18 weeks (range 16-20). The mean total cost was 1276 Euros for the autograft group and 2978 Euros for the bone substitute group.

Discussion :

The use of autogenous graft from the ipsilateral femoral condyle following open reduction and internal fixation of depressed tibial plateau fractures provided enough bone to maintain the height of the tibial plateau and was not associated with any donor site morbidity. Using this method, the surgical time was not significantly elongated and the rehabilitation was not affected. It also exhibited faster fracture healing without postoperative loss of reduction and it was less expensive than the use of bone substitutes.

Bone graft substitutes currently available in orthopaedic practice: the evidence for their use

We reviewed 59 bone graft substitutes marketed by 17 companies currently available for implantation in the United Kingdom, with the aim of assessing the peer-reviewed literature to facilitate informed decision-making regarding their use in clinical practice. After critical analysis of the literature, only 22 products (37%) had any clinical data. Norian SRS (Synthes), Vitoss (Orthovita), Cortoss (Orthovita) and Alpha-BSM (Etex) had Level I evidence. We question the need for so many different products, especially with limited published clinical evidence for their efficacy, and conclude that there is a considerable need for further prospective randomised trials to facilitate informed decision-making with regard to the use of current and future bone graft substitutes in clinical practice.