Intramedullary Bone Grafting for Open Tibial Shaft Fractures

Overview

This study will examine if there is a difference between the time to full union between the control group and the study group. Each group will be composed of patients who have an open fracture in the mid tibia. Both groups will undergo primary fixation via reamed intramedulary nailing (IMN), a common treatment for tibia shaft fractures in adults. The study group will have a bone graft applied to the open cortex of the fracture. The bone graft will be composed of the intramedullary reamings, which are a byproduct produced when the intramedullary canal is reamed in preparation for insertion of the IMN.

Open fractures of the tibial diaphysis are known to have high rates of nonunion or delayed union, with widely varying nonunion rates reported to be between 15% and 60% even in lower Gustilo Anderson grade (types I, II, and IIIA) open fractures. Nonunions are costly as they require more healthcare services and result in increased patient pain and disability. A previous study has demonstrated that the use of bone morphogenic protein (BMP) at the time of definitive tibial shaft fracture fixation significantly reduced the risk of delayed union. However, BMP is costly and is rarely used for this purpose. Intramedullary bone graft (IMBG) collected by the reamer-irrigator-aspirator (RIA) technique has been shown to be effective for producing bone graft to stimulate healing and treat larger defects in long bones as well as in the treatment of nonunions. However, the RIA apparatus also introduces and extra expense to the operation and produces more bone graft than would be needed for packing of the open cortex in non-segmental fractures without bone loss. The investigator's study aims to determine if packing the exposed fracture cortex with a small volume of IMBG collected from the tip of a standard reamer during intramedullary nailing can effectively reduce rate of delayed union and nonunion in open tibia shaft fractures. This will be a prospective interventional study with two randomized, parallel groups. Patients with an open diaphyseal tibial fracture will be considered for study inclusion. Patients who consent to participate in the study will be randomized to one of two groups. The first will be the control group. This group will receive the standard of care for their injury, which consists of irrigation and debridement of the open fracture, reamed intramedullary nailing and primary wound closure. The second group, the intervention group, will also undergo irrigation and debridement of the open fracture with reamed intramedullary nailing, but will also receive a bone graft on the exposed cortex of the tibial fracture before primarily closing the wound. The bone graft will be made up of the product of the intramedullary reaming prior to the insertion of the intramedullary nail. This bone graft will be collected by wiping the reamings from the reamer tip into a sterile, pre-weighed container after each pass of the reamer through the medullary canal. Prior to introducing the graft into the exposed cortex, the graft will be weighed so that a record may be kept of the amount of graft collected and subsequently used in the procedure. Each group will then receive identical follow-up care with clinic visits at 2, 8, 16, and 24 weeks post operatively, and will receive X-rays at the 8, 16, and 24 week visits. Each radiograph will be evaluated and assigned a Radiographic Union Scale in Tibial fractures (RUST) score by an independent evaluator. Additionally, the Lower Extremity Functional Scale (LEFS) questionnaire will be administered at enrollment, 8, 16, and 24 week visit to objectively measure patient progress in functional outcomes. The primary outcome measurement will be the rate of union of the fracture in both groups at 3 and 6 month follow up. Radiographic union of the fracture will be defined as the presence of cortical bridging on at least 3 of the 4 cortices or RUST score \>10. Delayed union will be defined as failure to achieve cortical bridging on 3 of 4 cortices or a RUST score \>10 by 6 months. Nonunion will be defined as a fracture that in the opinion of the treating surgeon has no possibility of healing without further intervention.