Bone graft substitutes for the treatment of traumatic fractures of the extremities.

UNLABELLED: HEALTH POLITICAL AND SCIENTIFIC BACKGROUND: Bone graft substitutes are increasingly being used as supplements to standard care or as alternative to bone grafts in the treatment of traumatic fractures.

RESEARCH QUESTIONS: The efficacy and cost-effectiveness of bone graft substitutes for the treatment of traumatic fractures as well as the ethical, social and legal implications of their use are the main research questions addressed.

METHODS: A systematic literature search was conducted in electronic medical databases (MEDLINE, EMBASE etc.) in December 2009. Randomised controlled trials (RCT), where applicable also containing relevant health economic evaluations and publications addressing the ethical, social and legal aspects of using bone graft substitutes for fracture treatment were included in the analysis. After assessment of study quality the information synthesis of the medical data was performed using metaanalysis, the synthesis of the health economic data was performed descriptively.

RESULTS: 14 RCT were included in the medical analysis, and two in the heath economic evaluation. No relevant publications on the ethical, social and legal implications of the bone graft substitute use were found. In the RCT on fracture treatment with bone morphogenetic protein-2 (BMP-2) versus standard care without bone grafting (RCT with an elevated high risk of bias) there was a significant difference in favour of BMP-2 for several outcome measures. The RCT of calcium phosphate (CaP) cement and bone marrow-based composite materials versus autogenous bone grafts (RCT with a high risk of bias) revealed significant differences in favour of bone graft substitutes for some outcome measures. Regarding the other bone graft substitutes, almost all comparisons demonstrated no significant difference. The use of BMP-2 in addition to standard care without bone grafting led in the study to increased treatment costs considering all patients with traumatic open fractures. However, cost savings through the additional use of BMP-2 were calculated in a patient subgroup with high-grade open fractures (Gustilo-Anderson grade IIIB). Cost-effectiveness for BMP-2 versus standard care with autologous bone grafts as well as for other bone graft substitutes in fracture treatment has not been determined yet.

DISCUSSION: Although there were some significant differences in favour of BMP-2, due to the overall poor quality of the studies the evidence can only be interpreted as suggestive for efficacy. In the case of CaP cements and bone marrow-based bone substitute materials, the evidence is only weakly suggestive for efficacy. From an overall economic perspective, the transferability of the results of the health economic evaluations to the current situation in Germany is limited.

CONCLUSIONS: The current evidence is insufficient to evaluate entirely the use of different bone graft substitutes for fracture treatment. From a medical point of view, BMP-2 is a viable alternative for treatment of open fractures of the tibia, especially in cases where bone grafting is not possible. Autologous bone grafting is preferable comparing to the use of OP-1. Possible advantages of CaP cements and composites containing bone marrow over autogenous bone grafting should be taken into account in clinical decision making. The use of the hydroxyapatite material and allograft bone chips compared to autologous bone grafts cannot be recommended. From a health economic perspective, the use of BMP-2 in addition to standard care without bone grafting is recommended as cost-saving in patients with high-grade open fractures (Gustilo-Anderson grade IIIB). Based on the current evidence no further recommendations can be made regarding the use of bone graft substitutes for the treatment of fractures. To avoid legal implications, use of bone graft substitutes outside their approved indications should be avoided.