Early prediction of tibial and femoral fracture healing: Are we reliable?

INTRODUCTION: To evaluate the ability of orthopaedic trauma subspecialists to predict early bony union in femoral and tibia shaft fractures. MATERIALS AND METHODS: Eight orthopaedic trauma subspecialists prospectively predicted the probability of bony union at 6 and 12 weeks post-operatively for an aggregate of 48 femoral and tibial shaft fractures treated at a Level 1 trauma centre. An additional orthopaedic trauma subspecialist was blinded to treating surgeon and adjudicated healing at 18 weeks. The Squared-Error Skill Score (SESS) determined the likelihood of accurate forecasting for bony union. RESULTS: Nine patients were lost follow-up, resulting in 39 fractures (81.25% retention) including 20 femoral and 19 tibial fractures. Fourteen fractures were open, 15 were not-yet united at final follow-up. SESS values were 0.25-0.77. The ability to predict union (sensitivity) was 1.000. The ability to predict nonunions (specificity) was 0.330-0.500. The probability of a correct predicted union was 0.727 and correct predicted nonunion at final follow-up was 1.000. AO/OTA type A fractures pattern predictions were highly accurate. As body mass index increased, predictions trended toward decreased accuracy (p=0.06). Tobacco use, age, gender, associated injuries, open fractures, and surgeons' years in clinical practice were not associated with accuracy of predictions. CONCLUSIONS: At 12-weeks post-operatively orthopaedic trauma subspecialists can confidently predict the union state in this patient population. This data is most useful in the nonunion patient, directing early intervention, thereby decreasing patient disability and discomfort.

Canine investigation of rhBMP-2, autogenous bone graft, and rhBMP-2 with autogenous bone graft for the healing of a large segmental tibial defect.

OBJECTIVE: The purpose of this study was to compare the effects of bone morphogenetic protein, bone morphogenetic protein with autogenous bone graft (ABG), and ABG alone on the healing of a large bone defect in the canine tibia. METHODS: Fifteen 45- to 55-lb canines were randomly assigned to 1 of 5 treatment groups, 3 per group. The groups included (1) recombinant human bone morphogenetic protein (rhBMP-2, 0.43 mg/mL)/absorbable collagen sponge (ACS) + collagen/ceramic matrix (CCM), (2) rhBMP-2 (0.22 mg/mL) ACS + CCM, (3) rhBMP-2 (0.43 mg/mL) ACS + ABG, (4) rhBMP-2 (0.22 mg/mL) ACS + ABG, and (5) ABG alone. A 5-mL defect was created in the right tibia and fixed with a 4.5 mm locking plate and 1 of the grafts described above implanted. X-rays were taken biweekly for 12 weeks and evaluated for radiographic union. Representative histology was also examined. RESULTS: All defects treated with rhBMP-2 (any combination) healed at 6.0 +/- 0.9 weeks. None of the ABG alone-treated defects were healed at 12 weeks. Dogs receiving rhBMP-2/ACS + CCM healed at 5.7 +/- 0.8 weeks, whereas rhBMP-2/ACS + ABG defects healed at 6.3 +/- 0.8 weeks. Histology showed healing consistent with 12-week radiologic results. CONCLUSIONS: Large segmental defects in canine tibiae can be effectively healed with stable fixation and rhBMP-2/ACS + ABG or CCM. These conclusions may offer insight into the clinical treatment of segmental defect nonunions in the human.