A Prospective Randomized Controlled Trial on the Use of Bone Morphogenetic 7 (BMP-7) (OP-1®) and Demineralized Bone Matrix in Tibial Non-union

Inclusion Criteria: * Diaphysary tibial non-unions will be included (9 months after first surgery) * Major surgery includes exchange nailing, bone grafting, internal fixation, amputation and soft-tissue coverage procedures, such as delayed primary closure and free flaps * Surgery is classified as minor for removal of external fixator pins for local infection and removal of a static locking screw from intramedullary nails, a procedure known as dynamization * ASA 1 and ASA 2 * Gap length/bone contact detected (1-5 cm): largest cortical gap in any radiographic incidence * Subject or legal guardian is willing and able to understand, sign and date the study specific Patient Informed Consent, which has been approved by the Institutional Review Board * Agrees to participate in post-operative evaluations and required rehabilitation regimen Exclusion Criteria: * Patients with known hypersensitivity to the active substance or collagen * Gap more than 5 cm * Immature skeleton * Known auto-immune disease, including rheumatoid arthritis, systemic lupus erythematosus, scleroderma, Sjögren's syndrome and dermatomyositis/polymyositis * Active infection on unhealed site or active systemic infection * Non-healing resulting from pathological fractures, tumours or metabolic bone diseases * Presence of tumour in vicinity of non-union * Patients receiving chemotherapy, radiotherapy or immunosuppressant treatment or excessive steroids * Patients with severely compromised soft tissue coverage or vascularisation at the non-union site, sufficient to impair bone healing * Patients with congenital non-union * Pregnancy and lactation * Non-union of multiple bones interfering with walking * Patients with neuromuscular diseases or conditions interfering normal weight bearing * Patients who, judged by the surgeon, are candidates for just internal fixation alone