Factors Affecting Outcomes of Hindfoot Fusion Nails for Acute Injury: A Multicenter Study

To evaluate the effect of joint preparation and patient factors on outcomes and complications in patients treated acutely with hindfoot fusion nails for ankle and pilon fractures.

Retrospective chart review.

Thirteen US trauma centers and 2 UK trauma centers.

Ankle and pilon fractures (AO-OTA types A-C) from 2010 to 2020 acutely treated definitively with hindfoot fusion nail were reviewed. Patients at least 18 years old and with minimum 6 months follow-up or earlier diagnosis of complication were included. Exclusion criteria included nonambulatory at baseline, prior internal fixation that failed and underwent revision, and prior tibiotalar or subtalar arthrodesis.

The primary outcome was final postoperative ambulatory status. Secondary outcomes were infectious and fracture-related complications.

One hundred forty-nine patients (75 men; 74 women; age 20-99; median 63 years) were treated for ankle (104) or pilon (45; 8A, 13B, 24C) fractures. Eighty-five patients (44%) had open fractures and 55 (37%) had diabetes. Thirty-six patients (24%) had joint preparation at the time of surgery. Forty-five (30%) were made weight bearing as tolerated postoperatively; the median time to mobilize was 1.5 days (0-210) and to full weight bearing was 35 days (0-1462). Fifty-seven patients (85%) returned to their preinjury ambulatory status, which was not affected by joint preparation (50% vs. 59%, P = 0.327). Joint preparation led to higher articular fusion rates (94% vs. 24%; P = 0.001) and fewer hardware removals (19% vs. 42%, P = 0.013), but trended toward a higher fracture nonunion rate (19% vs. 8%, P = 0.053). Forty-five patients (30%) had infectious complications, 60 (40%) had a fracture-related complication, and 67 (45%) had additional procedures. Open fractures did not lead to any differences in superficial or deep infection. Insulin-dependent diabetes was associated with higher rates of infectious complications (31% vs. 15%, P = 0.028) and amputation (17% vs. 4%, P = 0.029).

Hindfoot fusion nails for acute ankle and pilon injuries had high complication rates. More complications occurred in patients with insulin-dependent diabetes. While 95% regained ambulation, only 57% returned to preoperative status. Joint preparation led to higher rates of articular fusion (94% vs. 24%, P < 0.001) but not fracture union (81% vs. 66%, P = 0.106).

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.