Intramedullary Bone Grafting for Open Tibial Shaft Fractures

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 increase rates of
union of the open cortex and consequently 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 exposed cortices in both groups at 3 and 6 month follow up.
For purposes of this study, union of the exposed cortex will be defined as bony callus
formation with obscuration of the initial fracture line. 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.

Inclusion Criteria:

- Patient age 18 or older

- Patient with a Gustillo I, II, or IIIa open tibia shaft fracture to be treated
primarily with an intramedullary nail

- Primary closure of the open fracture wound during the initial operation

- Consent to participate in the study.

- Are able and willing to return to the hospital or clinic for follow-up for a period of
6-9 months or until radiographic union.

Exclusion Criteria:

- Patients under the age of 18.

- Patients who are pregnant

- Patients with segmental tibia fractures or those with loss of bone

- Patients with skin defects over the tibia that cannot be closed primarily

- Patients with a pathologic fracture of the tibia

- Patient has quadriplegia or paraplegia