Restoration of Anatomic Parameters and Syndesmotic Reduction After Intramedullary Nailing of Distal Fibular Fractures

Abstract

Background: Intramedullary nailing of the fibula (FN) is a method of fixation that has proven to be useful for treating distal fibular fractures (DFs). FN minimizes soft tissue complications and provides similar stability to plating, with fewer hardware-related symptoms. Nevertheless, FN has been associated with syndesmotic malreduction and the incapacity of restoring length and rotation of the fibula. We aimed to evaluate the fibular position and syndesmotic reduction after fixation with FN compared with the uninjured ankle in the immediate postoperative period.

Methods: Prospective cohort study. Patients with DF fractures treated with IN between January 2017 and January 2020 were included. Immediate postoperative bilateral ankle CT was obtained in all cases. Fibular rotation, length, and translation as well as syndesmotic diastasis were measured on both ankles and compared by 3 independent observers.

Results: Twenty-eight patients were included (16 women). The mean age was 46 years (range 16-91). Fracture type distribution according to AO/ASIF classification included 19 patients with 44.B (67.9%), 8 patients with 44.C (28.6%), and 1 patient with a 44.A fracture (3.6%). No significant differences were identified considering fibular rotation (P = .661), syndesmotic diastasis (P = .147), and fibular length (P = .115) between the injured and uninjured ankle. Fibular translation had statistical differences (P = .01) compared with the uninjured ankle. The intraclass correlation coefficient showed an excellent concordance between observers except for fibular translation on the injured ankle.

Conclusion: In this cohort, fixation of DF fractures with FN allows restoration of anatomical parameters of the ankle in terms of fibular rotation, length, and syndesmotic diastasis. However, fibular translation had significant differences compared with the uninjured ankle based on bilateral CT scan evaluation.

Level of evidence: Level II, prospective cohort study.

Keywords: distal fibular fracture; fibular nail; intramedullary fixation; syndesmosis.

Figure 1.

Fibular nailing of displaced malleolar fracture. (A, B) Anteroposterior and lateral radiograph of a Weber B ankle fracture. (C, D) Percutaneous reduction using clamps before nail installation. (E, F) Final intraoperative result.

Figure 2.

Postoperative bilateral computed tomographic scan imaging. (A) Coronal views. (B) Axial views. A slight anterior translation and overcompression is noted.

Figure 3.

Diastasis and anteroposterior translation measurements. (A) Line A unites the middle point of the 2 lines crossing the longest diameter both on the tibia and the fibula. (B) Tibiofibular diastasis was measured along with line A between the medial cortex of the tibia and the lateral cortex of the fibula. (C) Line B is drawn parallel to line A along with the most anterior point of the tibial cortex. Line C is drawn along the most lateral point of the anterior and posterior colliculi of the tibia. Anteroposterior translation (APT) corresponds to the distance between the most anterior aspect of the fibula and line B, parallel to line C. Redrawn from Prior CP, Widnall JC, Rehman AK, Weller DM, Wood EV. A simplified, validated protocol for measuring fibular reduction on ankle CT. Foot Ankle Surg. 2017;23(1):53-56.

Figure 4.

Fibular length and rotation measurements. (A) Line D is drawn following the anatomical axis of the fibula and a second line perpendicular to line D at the level of the most lateral region of the tibial plafond (line E). Fibular length corresponds to the distance between the tip of the fibula and line E. (B) Fibular rotation was determined using the angle conformed by the line that unites the anterolateral and posterolateral distal tibia tuberosities and the line that unites the anterior and posterior fibular tuberosities. Redrawn from Prior CP, Widnall JC, Rehman AK, Weller DM, Wood EV. A simplified, validated protocol for measuring fibular reduction on ankle CT. Foot Ankle Surg. 2017;23(1):53-56.