The Incidence of Posterior Malleolar Involvement in Distal Spiral Tibia Fractures: Is it Higher than We Think?

OBJECTIVES:
To investigate the incidence of concomitant posterior malleolar fractures (PMFs) in operative, distal-third, spiral tibia fractures.

DESIGN:
Prospective protocol with retrospective review of data.

SETTING:
Single, Level 1 trauma center.

PATIENTS/PARTICIPANTS:
One hundred ninety-three consecutive, skeletally mature patients with operatively treated fractures of the distal-third, tibial shaft and metaphysis. Pilon fractures were excluded.

INTERVENTION:
Computed tomography (CT) scans were obtained in all distal-third, spiral fractures of the tibia to determine fracture morphology and presence of a PMF.

MAIN OUTCOME MEASUREMENTS:
The incidence of concurrent PMFs in operative spiral fractures of the distal tibia.

RESULTS:
Twenty-six distal-third, spiral fractures were identified with an ipsilateral PMF diagnosed in 92.3% of cases (24 cases). PMFs were over 25 times more likely to occur in distal-third, spiral fractures when compared with other distal-third fracture patterns (relative risk = 25.7, 95% confidence interval, 11.6-56.8). PMFs were treated with supplemental fixation in 23/24 (95.8%) cases.

CONCLUSIONS:
There is a high incidence of concomitant, ipsilateral fractures of the posterior malleolus in patients presenting with operative distal-third, spiral fractures of the tibia. A preoperative ankle computed tomography should be strongly considered in all cases with this specific fracture morphology.

LEVEL OF EVIDENCE:
Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.