Functional Outcomes of Patients Undergoing Anterolateral versus Anteromedial Approaches of the Ankle for Pilon Fractures

Tyler J. Jenkins BS, Michael Khazzam MD, Gregory J. Della Rocca, MD, PhD, Allison M Wade MD, Yvonne M. Murtha MD, and Brett D. Crist MD

Introduction:Pilon fractures involve the distal tibia and are often associated with a corresponding fibula fracture. These fractures mainly result from high energy accidents such as falling from a high surface or motor vehicle accidents. Pilon fractures continue to challenge even the most experienced orthopedic traumatologists. Many studies have been published showing the high incidence of complications as well as the difficulties in treating this fracture. The current treatment protocol for open reduction and internal fixation (ORIF) of pilon fractures uses a two-staged approach and has been shown to decrease the risk of complications compared to primary ORIF. This two-staged protocol involves external fixation of the tibia and usually ORIF of any fibula fracture (Fig 1B). Once the swelling and soft-tissue injury resolve (10-21 days) the second stage is completed with definitive open reduction and internal fixation of the tibia(Fig 1C).

Careful preoperative planning is crucial to achieving desirable clinical outcomes, but currently the literature does not reach a consensus on which surgical approach is optimal. This study examines the functional outcomes of two of the most common surgical approaches for pilon fractures, the traditional anteromedial approach and the more recently described anterolateral approach. The anterolateral approach is thought to produce better outcomes because of the greater amount of visualization in the articular surface and greater soft-tissue coverage for the implant.

Results:23 of the 39 patients had undergone fixation using the anterolateral approach and had an average AO/OTA pilon fracture classification of C2-C3. 14 of the 39 patients had fracture fixation using the anteromedial approach and had an average AO/OTA pilon fracture classification of B3-C1. 2 of the 39 patients in the study had fracture fixation with both the anterolateral and anteromedial approach with an average fracture classification of C2-C3. The was no significant difference (p=0.9270) in MFA scores between the anterolateral and anteromedial groups (35.26 AL and 32.64 AM) but the patients that had both approaches had a significantly worse outcome of 40. Likewise there was no significant difference (p=0.9170) for in FFI scores between the groups (45.56 and 42.13 respectively) and the group that had both approaches had a higher value of 57.15.

AL (23) AM (14) AM & AL (2)

Total MFA Score 35.26 32.64 40

Patient Rating Subscore 2.41 2.33 3.03

Move Stand. Score 39.57 38.21 60

Fine Stand. Score 8.7 12.25 0

Home Stand. Score 46.86 37.3 55.56

ADL Stand. Score 17.39 17.06 8.34

Sleep Stand. Score 45.65 42.86 58.34

Leisure Stand. Score 69.57 58.93 75

Relationship Stand. Score 17.39 26.43 20

Cognition Stand. Score 28.26 28.57 0

Emotion Stand. Score 50 41.67 58.34

Job Stand. Score 50 41.07 62.5

FFI Total Score 45.56 42.13 57.15

FFI Pain Subscore 45.96 49.61 67

FFI Disability Subscore 46.23 42.38 67.78

FFI Activity Limitation 44.78 34.4 36.67

Time From Surgery to Survey 3.28 yr 3.54 yr 3.35 yr

Average Fracture Classification C2-C3 (2.580) B3-C1 (1.90) C2-C3 (2.50)

Table 2: Functional Outcome Comparison between the Anterolateral and Anteromedial Approaches to Pilon Fracture Fixation

Pilon Fracture AO Morphological Classification

Numerical Value

A1 1/3A2 2/3A3 3/3B1 4/3B2 5/3B3 6/3C1 7/3C2 8/3C3 9/3

Discussion:The outcomes of the two different approaches did not produce a statistically different outcome (p-values of .9270 for MFA comparison and .9170 for FFI comparison). Yet the significantly higher fracture classification of the anterolateral approach patients (C2-C3 compared to B3-C1) would be expected to produce worse clinical outcomes than the anteromedial group. The improved long-term functional outcomes from the anterolateral incision may result from the greater amount of soft tissue coverage for the implant and better visualization of the articular surface. The improved soft-tissue coverage decreases the incidence of soft tissue complications. Visualization enhancement of the articular surface allows easy access to the distal tibia and tibiotalar joint where all class C fractures appear. It is also worth noting that a majority of AO/OTA classified C3 fractures occur on the anterolateral side of the tibia and therefore this approach will yield better visualization for the worst possible classified pilon fractures. Although the sample size may be relatively small and a larger series may prove significant differences, we can conclude that the anterolateral approach does improve long-term functional outcomes of patients with pilon fractures. Although fracture pattern and soft tissue coverage are the primary issues that determine surgical approach, it appears that in C-type pilon fractures that have anterolateral comminution, the anterolateral approach will produce functional outcomes similar to less complicated pilon fractures addressed through the traditional anteromedial approach.