Little literature exists about how trauma-induced anemia affects bone healing. Moreover, the definition of anemia has now changed. Until recently, anemia was defined as peripheral Hemoglobin (Hgb) of less than 10 grams/deciliter (gm/dL). Contemporary literature defines anemia as Hgb < 8gm/dL.

This re-definition prompted three questions: (1) Does the presence of hemorrhagic anemia (Hgb< 10gm/dL) alter bone healing rates?; (2) If not, does the newer definition (Hgb< 8gm/dL) influence bone healing?; (3) If so, does the newer definition result in more profound changes in bone healing than those previously seen?

We reviewed the charts of patients treated for long bone, diaphyseal fractures over a ten-year period at a Level 1 Trauma Centre to determine rates of fracture healing when anemia by either definition was present. Patients who were skeletally immature, died during hospitalisation, or had incomplete medical records were excluded. All charts were reviewed for: development of anemia, need for blood transfusion, quantity of blood administered and subsequent association with bone healing. Inclusion criteria were met by 627 patients (700 individual fractures).

When anemia was defined as Hgb< 10gm/dL, there was an 81.5% healing rate among anemic patients vs 88.8% in non-anemic patients (p=0.013); with a definition of Hgb< 8gm/dL, healing rates were 81.3% and 86.2%, respectively (p=0.041). Tibial healing was especially noted to be influenced (p = 0.002 and 0.0001, respectively). Femoral healing was likewise, but less dramatically, affected (p = 0.0082 and 0.0843). ANOVA showed no significance for open vs closed status, or NSAID use.

Our study found a statistically significant difference in long bone healing between patients who developed anemia and those who did not. This is the first evidence based clinical review demonstrating that hemorrhagic anemia has a significant impact on the healing rates of long bone fractures, especially those of the tibia.