Preoperative CT Scans Prior to Distal Tibial Intramedullary Nailing Do not Change Treatment Decisions or Surgical Outcomes.

INTRODUCTION

Distal tibia shaft fractures have a high association with posterior malleolar fractures (PMFs); hence, a preoperative ankle CT scan is commonly obtained. The purpose of this study was to determine whether a CT scan for distal third tibia shaft fractures is associated with differences in recognition of a posterior malleolus fracture (PMF), treatment of an identified PMF, outcomes, and postoperative complications.

METHODS

We retrospectively reviewed cases of adult patients with distal third tibia shaft fractures treated with an intramedullary nail between 2018 and 2020. Patients were divided into 2 groups based on whether they received a preoperative ankle CT scan. Outcomes included surgical time, the rate of missed PMFs or postoperative PMF displacement, the treatment of the PMFs, postoperative weight-bearing restrictions, Patient-Reported Outcomes Measurement Information System Global-10 (PROMIS Global-10) scores, and unplanned revision surgeries.

RESULTS

124 patients (age 45 ± 18 years; 39.5% female) with distal third tibia shaft fractures treated with intramedullary nailing and with minimum 6 months of follow-up were reviewed. 26 patients received preoperative CT scans, and 98 patients did not have CT scans. The rate of detected PMF was 69.2% (N = 18) in patients with CT and 55.1% (N = 54) in patients without CT ( P = 0.19). No significant differences were observed in all outcomes between the 2 groups ( P > 0.05). 3 PMFs not visible on radiographs were identified on CT, and they did not require fixation and did not displace. PMFs that were greater than one-third of the joint surface were more likely to have a preoperative CT ( P < 0.01).

DISCUSSION

Preoperative CT scans for distal third tibia shaft fractures may be useful in characterizing large PMFs; however, this knowledge does not translate into shorter surgical time, increased fixation rates, decreased unplanned revision surgery, or improved patient-reported outcomes. Discovery of PMFs did not always lead to fixation, and PMFs without fixation did not become further displaced.