The findings of our study revealed that the unstable ITF group had a significantly higher Hb drop after adjusting for other factors (β = 0.51; p = 0.04). There were no significant differences between the two groups with respect to sex, age, time interval between injury and surgery, operation time, BMD, ASA classification, BMI, and the number of patients taking anticoagulants. ITFs are one of the most common fractures in the elderly. Patients with ITFs can have blood loss from the fracture itself and can become dehydrated before the fracture is diagnosed and repaired. Therefore, the preoperative Hb level may not reflect the real blood loss and is frequently underestimated (9). There are some factors that affect the total blood loss after ITF. First, blood loss due to trauma is the most significant reason and likely causes of the greatest Hb drop (9, 10). Second, the surgical approach also affects the total blood loss; in particular, the blood loss increases when reduction with an intramedullary nail is performed (11). Intramedullary nail reduction is a common treatment for ITF and it can also cause a greater hidden blood loss than other approaches (11).
Compared to femoral neck fractures, ITFs are extracapsular, which means they are associated with greater blood loss. Blood loss from cancellous bones in ITFs is usually significant (10), and the total blood loss affects the pre- to postoperative Hb drop. Therefore, the Hb drop in ITFs is more obvious than that in femoral neck fractures (10).
There are several risk factors that affect the Hb level when patients sustain ITFs and undergo intramedullary nail fixation (12-14). A comminuted fracture usually causes more blood loss than a simple fracture (15, 16). In their case series, Ronga et al. and Torres et al (15, 16). reported more blood loss in AO 31-A2 fractures than in AO 31-A1 fractures. Our study showed a greater Hb drop in the unstable group, according to the AO classification. The unstable group of ITFs also revealed a greater Hb drop during the perioperative period. The risk factors for greater blood loss and hidden blood loss are age, time interval between injury and surgery, operation time, BMI, presence of diabetes mellitus, and the use of anticoagulants (15-20).
In our study, ITFs were defined according to the Sonawane’s criteria (8), which classified them into two groups: AO 31-A1.1 through A2.1 (commonly described as stable) and AO 31-A2.2 through A3.3 (described as unstable). In our study, we excluded the AO 31-A3 group due to the small number of patients and the different trauma biomechanics of patients with this fracture type (fracture line away from the greater and lesser trochanters) compared to AO 31-A1 and A2 fractures. AO 31-A3 fractures are reverse oblique fractures, simple transverse fractures, or shaft and subtrochanteric extensions. Moreover, a study showed that ITFs classified as AO 31-A3 with intramedullary nail reduction have a lower operation time and are less likely to require blood transfusion (21). Therefore, including these fractures in the unstable group might have prevented us from identifying a greater Hb drop.
The unstable group showed a higher Hb drop compared to the stable group (β = 0.51; p = 0.04). However, the other analyzed factors showed no significant differences in our study. This might be due to the small number of cases. On the other hand, we excluded all patients who immediately received blood transfusion at the emergency room. Therefore, we could have excluded patients with major blood loss and this could have affected our findings. We also excluded patients <60 years old because we wanted to focus on the older population, with a higher prevalence of ITF.
Due to the aforementioned risk factors, a greater Hb drop will cause more complications. The Hb drop in the ITF perioperative period is affected by the amount of blood loss due to the fracture and the severity of dehydration (19). The Hb drop is a significant postoperative complication; previous studies have shown that it may be a predictive factor of mortality rate after ITF (22, 23).
The presence of anemia, either pre- or postoperatively, causes significant effects in older patients after ITF reduction (12, 24-26). Anemia within the ITF preoperative period and greater perioperative blood loss are poor prognosis factors associated with higher postoperative mortality rate, higher risk of bed-related complications (i.e., pneumonia, urinary tract infections, and deep vein thrombosis), increased length of hospital stay, increased readmission rate, poor physical performance, and poor functional recovery (27, 28). ITFs have a higher mortality rate than femoral neck fractures, particularly during the first year after discharge (10). We did not analyze the postoperative follow-up in these patients; therefore, we could not confirm that a higher mortality rate is associated with unstable ITFs. Our study could serve as a reference for future studies that will compare the one-year mortality rates between stable and unstable fractures.
The ITF mortality rate has been associated with anemia and surgical delay (29, 30). The appropriate time for ITF surgery is within 24 and 72 hours of the occurrence of trauma (31-33). Surgery within 48 hours of admission after ITF will reduce the hospital stay, mortality rate, and perioperative complications (29, 30). If the length of time between admission and surgery is >24 hours, patients will have lower blood loss. The hematoma formation may produce local pressure at the fracture site to reduce the total blood loss (15). Postoperative anemia is correlated with an inferior functional recovery and a detrimental effect on mortality. Therefore, aggressive pre-surgical management, such as blood transfusion, may improve the overall outcome in patients who are expected to have more blood loss (34).
Preoperative and trauma-related blood loss is unavoidable; however, if more attention is paid to patients who have a greater bleeding risk and higher complication rate, they can be treated aggressively, for example, with preoperative blood transfusion, intraoperative blood transfusion, and reduced surgery time. This may lead to a better prognosis by reducing postoperative complications, the average length of hospital stay, average medical costs, and one-year mortality rate. However, the preferred transfusion regimen, especially in patients with pre-existing cardiorespiratory diseases, remains controversial (35, 36). A liberal blood transfusion may result in pro-inflammatory, immunomodulating, and prothrombotic effects (37), which could cause serious systemic complications, such as cardiovascular events. Carow J et al. (38) reported that a liberal blood transfusion causes higher cardiorespiratory complications in patients with trochanteric femoral fractures. We believe that the prediction of Hb drop will be helpful when blood transfusion is being considered in such fragile patients.
The Hb level considered to be a “trigger” for blood transfusion remains controversial, especially in elderly patients (39). For elderly patients, careful transfusion practices to maintain Hb thresholds of 9–10 g/dl are indicated (39). Therefore, we could consider aggressive blood transfusion before surgery to reduce postoperative anemia (hemoglobin < 9 g/dl).
Diabetic or other medical statuses may influence Hb values especially in fragile elderly patients. However, our study exclusively focused on the parameters that may have a direct impact on significant hemorrhage, such as fracture type, age, BMI, and anticoagulation agents; the influences of these medical issues were not evaluated in our study.
Both Hb and Hct are used as evaluation methods for anemia. According to previous studies, Hb level provides a direct measure of the oxygen-carrying capacity while Hct provides an indirect measure (40). Therefore, Hb level is routinely used for anemia assessment at our institution, and we used this measure in our study.
The small number of cases is the greatest limitation to our study. Patients who underwent blood transfusion and were excluded accounted for about one-third of all cases at the period of initial data collection. The technical performance of the surgeons and their overall experience also affects the outcomes in AO 31-A3 fractures, in terms of reduction in skill and operation time. Furthermore, the external validity of this study could only be applied to the older patients (> 60 years old) who had unstable ITFs. Also, due to the small number of cases included in this study, the external validity may be limited by age, AO classification, and number of cases. Future studies should include more cases and a longer follow-up time to assess the mortality rate between a preoperative aggressive blood transfusion group and nonaggressive blood transfusion group.