Purpose: Bone grafting of subchondral voids during ORIF of tibial plateau fractures is commonly performed. The efficacy of various graft materials to resist post-operative articular displacement and stimulate bone regeneration in the grafted zone, remains largely unstudied. Studies in animals with a new composite material have shown that this composite material leads to greater bone formation and stronger bone versus autograft at 13 and 26 weeks. This study was designed to determine whether this material helps resist articular fragment displacement and leads to stronger bone regeneration and better functional outcome in the treatment of tibial plateau fractures.

Methods: Thirty four patients with unilateral tibial plateau fractures (OTA 41A-B), were enrolled in a prospective multicenter single cohort study. The treatment protocol included ORIF and defect augmentation with a composite bone graft substitute (PRODENSE®, Wright Medical Technology). Reduction and bone formation was evaluated and followed with both plain radiographs and CT scans obtained immediately postop and at 12 and 24 weeks. Functional outcome was assessed using the SMFA scores. CT analysis was performed by an independent musculoskeletal radiologist who quantified maintenance of reduction of the articular surface and bone density within the grafted area.

Results: Eighteen of the 34 enrolled patients were eligible for follow-up at 24 weeks (sixteen were not yet eligible for the 24 week time point). Mean change in articular reduction was 0.75mm, Density measures in the region of the initial subchondral void decreased from a mean of 1400 Hounsfield units at baseline (immediately post-op) to 600 at 24 weeks, suggesting bone regeneration and normal remodeling. Short form Musculoskeletal Function Assessment activity scores improved from 55.15 (SD=42.8) at baseline to 20.92 (SD=18.09) at 24 weeks. Complications include 1 DVT, 3 infections and 1 cellulitis, all of which resolved. There was an additional infection that required revision of the ORIF.

Conclusions and Significance: Serial CT evaluations revealed maintenance of post-operative reduction with displacement of less than 1mm. Bone density, in the region of the grafted area was near normal and confirms that the composite graft material promotes strong bone regeneration. Functional outcomes improved with time from surgery and approached that of uninjured cohorts.

This study documents the use of bone graft harvested by the RIA system and used in treating segmental bone loss in the femur and tibia following trauma.

Eight patients with segmental defects of the tibia or femur were enrolled in the study. The segmental defects were optimized for bone grafting by repeated debridements and muscle flap coverage as required. Graft was harvested from the ipsilateral femur via a percutaneous technique. Volumes of bone graft were recorded and then placed to the defect site during the same surgical procedure.

The average age of the patients was twenty-nine years (sixteen to forty-one years). In the five tibiae and three femora there were four grade IIIA, three grade IIIB and One grade IIIC injuries. Muscle flap coverage was required in four patients. The average size of defect was 7 cm (1–14.5 cm). The RIA grafting was performed at an average of three months (2.5 – 5 months) post injury. The average bone graft volume obtained was 73cc(45–90 cc). The average hemoglobin drop was 4.4g/dl(2.3 – 8.0 g/dl) and the average hematocrit drop was 12.3%(6–21%). One patient required transfusion. Donor site complications were limited to one post-operative bleed. Defect site complications included one wound dehiscence and two infections. Radiographic union of the defects was achieved at an average time of four months (two to twelve months).

Grafting of large segmental defects using RIA bone graft has resulted in union at an average of four months. This technique represents an alternative to bone transport for treatment of segmental defects.

Reamed Irrigation Aspirator (RIA) allows access to large volumes of bone graft from the femur through percutaneous technique. The grafting technique was utilized to obtain graft for eight segmental defects in the tibia and femur. These healed at an average of four months.