Enhanced external counterpulsation-assisted cannulated screw fixation promoted femoral neck fracture healing: a pilot randomized controlled trial.

BACKGROUND: Femoral neck fractures often lead to complications such as delayed union or nonunion due to limited blood supply to the femoral head. Enhanced external counterpulsation (EECP) is a non-invasive method that improves peripheral and tissue perfusion. This study aimed to evaluate whether postoperative EECP could promote fracture healing and improve hip function recovery after cannulated screw fixation for femoral neck fractures. METHODS: This single-center, prospective, randomized controlled trial included patients with acute femoral neck fractures eligible for cannulated screw fixation. Participants were randomized in a 1:1 ratio into two groups using a computer-generated random sequence. Group assignments were sealed in opaque envelopes to ensure allocation concealment. Baseline characteristics were comparable between groups. Three weeks postoperatively, patients in the EECP group underwent daily 1-hour EECP sessions for 7 consecutive weeks, while the control group received standard care without EECP. Color Doppler ultrasound was used to measure the peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI) of the medial femoral circumflex artery on the ipsilateral fracture side. Fracture union time, as well as the incidences of avascular necrosis of the femoral head (ANFH) and nonunion, were recorded. The Harris Hip Score (HHS) was assessed at 3, 6, and 12 months postoperatively. RESULTS: A total of 64 patients completed at least 24 months of follow-up, including 31 in the EECP group and 33 in the control group. After the final EECP session, the EECP group demonstrated significantly higher PSV and EDV values compared to the control group (both p < 0.0001; 95% CI: -10.55 to -7.42, -3.83 to -3.22, respectively), while RI values were significantly lower (p < 0.0001, 95% CI: 0.04 to 0.06). All fractures healed in both groups, but the mean healig time was significantly shorter in the EECP group (p < 0.0001, 95% CI: 1.24 to 2.72). There was no significant difference between the two groups in the occurrence rate of ANFH (p = 0.615, 95% CI: -3.08 to 0.54). At 3 months postoperatively, there was no significant difference in HHS between the two groups (p = 0.165, 95% CI: -3.08 to 0.54). However, at 6 and 12 months, the EECP group showed significantly higher HHS values compared to the control group (p < 0.0001, 95% CI: -10.91 to -7.36; p = 0.0006, 95% CI: -10.81 to -3.12, respectively). CONCLUSIONS: Enhanced external counterpulsation appears to be a safe and potentially beneficial adjunctive strategy for the management of femoral neck fractures treated with cannulated screw fixation. The application of enhanced external counterpulsation may promote fracture healing and facilitate hip function recovery by improving blood perfusion of the femoral head and the fracture site. NAME OF TRIAL REGISTRY: Chinese Clinical Trial Register (ChiCTR); Registration number: ChiCTR2000034312; Date of registration: 01/07/2020.