How Do Open Distal Tibia Fractures Differ from Open Tibial Shaft Fractures?

PURPOSE: The purpose of this study was to compare a cohort of open distal tibia fractures to open tibial shaft fractures in regards to injury severity, method of fixation, and outcomes. METHODS: This is a retrospective review of 49 open distal tibia fractures (group D) with a mean age of 8.7years and 56 open tibia shaft fractures (group S) with a mean age of 8.6years, treated from 2007-May2017 at a single level 1 pediatric trauma center. Mann Whitney test was used to compare means between groups. RESULTS: Extremely high energy trauma (ATV, GSW, vehicular collision, lawnmower, crush, fall >8 feet) was the mechanism of injury in 90% (44/49) in group D and 77% (43/56) in group S (p=0.119). Mean AIS lower extremity scores were significantly higher in group S compared to group D (2.74 vs 2.55, p=0.043), as were mean Injury Severity Scores (13.10 vs 9.36, p=0.053). There were more Gustilo type II fractures in group S (42% vs. 35%), and more Gustilo type III fractures in group D (51% vs 39%) which trended towards significance (p=0.0622). 88% (43/49) of open distal tibia fractures had ipsilateral fibular involvement, compared to 71% (40/56) of open tibial shaft fractures (p=0.054). Tibial fixation methods were statistically different between the 2 groups (Table 1, p=0.0377), but incidence of fibular fixation was not statistically different (group D-12% vs group S-5%, p=0.4348). While surgical time and fluoroscopy times were not significantly different between the two groups, group D had longer mean length of hospitalization (8.44vs6.36 days, p=0.006), mean duration of immobilization (135vs100 days, p=0.033), and longer mean time to full weight bearing (77vs40 days, p=0.006). Rate of hardware removal (group D-49%, group S-52%) and radiographic angulation at final follow-up were not statistically significantly different between the two groups (p>0.05). Mean time to union was prolonged for both groups (178 days group D-178 days, group S-139 days, p=0.231). CONCLUSIONS: Open distal tibia fractures are significant for extremely high energy of injury. Alternate methods of fixation for open distal tibia fractures such as external fixation, K wires, and ORIF are more likely to be utilized than flexible intramedullary nailing. Open distal tibia fractures have longer hospital stays, immobilization, and time to full weightbearing but radiographic outcomes and time to union are comparable. SIGNIFICANCE: This study increases awareness of the difference in injury severity, fixation methods, and clinical course between open distal tibia and open tibial shaft fractures.