LARGE BONE DEFECT REPAIR MODELS USING CELL-BASED CONSTRUCTS : A TRANSLATIONAL LACK OF EVIDENCE

Despite a constant improvement in the restoration of bony disorders, the treatment of skeletal defects in long bones remains a challenge for orthopaedic surgeons. The available surgical options enable them to restore the integrity of the skeleton, but with considerable morbidity due to a prolonged treatment with multiple surgical interventions in most cases. The holy grail of bone reconstruction by simply filling the defect with suitable biological potent stemcellscaffold combinations, usually classified as Advanced Therapy Medicinal Products (ATMPs), does not seem to be within a short term reach. Clinical attempts are scarce and often reported as case reports. A uniform protocol does not exist and experimental data are usually heterogenous and not comparable. Moreover their experimental design is not always ideal resulting in data that do not withstand the translation from bench to bedside. This may explain why most scientific results remain silent publications that never make their way to the clinic. The ‘ideal’ conditions in which the experiments were performed allow for an outcome that cannot be expected to occur in the clinical situation were the biological conditions are less favorable.