Morphological Study of the Proximal Fibular Articular Surface Using Computed Tomography: Which Side Is Preferred for Proximal Fibular Flap in Wrist Arthroplasty?

Although proximal fibular flaps have been widely applied in wrist arthroplasty, controversy remains regarding which side of the proximal fibula is better for reconstruction of the distal radius. If the articular surface of the proximal fibula shows dorsal tilting, the ipsilateral (right) proximal fibula should be harvested in right wrist arthroplasty because the articular surface of the distal radius normally has volar tilt. This study investigated anatomical similarities between the proximal fibular articular surface and the distal radius articular surface based on morphologic analysis of the proximal fibula using computed tomography (CT).  A total of 18 proximal fibulae from 18 adult volunteers were analyzed using CT. Tilt and length of the proximal fibular articular surface were measured in the section plane parallel to the proximal tibiofibular articular surface (simulated sagittal plane). The inclination angle of the articular surface was measured in the section plane perpendicular to the proximal tibiofibular articular surface (simulated coronal plane).  In the simulated sagittal plane, the articular surface of the proximal fibula showed a mean dorsal tilt of 4.1 degrees; the articular surface for each scan was 17.1 mm. In the simulated coronal plane, two articular surfaces were studied. The inclination angle of these surfaces was measured as 32.2 and 54.4 degrees, respectively.  CT analysis of the proximal fibular articular surfaces suggested that ipsilateral proximal fibular transfer can result in improved anatomic restoration of normal volar tilt of the distal radius due to dorsal tilt of the proximal fibular articular surface.