Is Far Cortical Locking More Effective Than Bicortical Locking in Treating AO 43A1-3 Fractures?

Extra-articular distal tibia fractures are uncommon; it constitutes less than 10% of all lower extremity fractures, but even if the fracture is closed, contusion and fracture blisters may accompany these fractures, which can be very effective in deciding the type of treatment because the soft tissue envelope surrounding the tibia is very thin. Discussions on the method of fixation of these fractures continue and seem to never end. Since comparative studies with two popular methods, intra-medullary nailing (IMN) and minimally invasive plate osteosynthesis (MIPO), eventually yielded similar results, the choice based on experience and patient-specific characteristics, described as surgeon comfort, has been more accepted.

Malunion after IMN is a common problem and may be caused by the gradual enlargement of the canal after the isthmus or the incomplete centering of the proximal insertion site of the nail. On the contrary, the most common complications reported after MIPO are delayed union, nonunion and infection. In the MIPO technique, angle-stable locked plates are used, which can prevent shear displacement and provide more than 0.2 mm of axial interfragmentary movement, allowing the formation of natural callus tissue. Different methods can be applied to make the partially rigid mechanical environment created by these plates more flexible. These can be diaphyseal fixation with conventional non-locking screws or far cortical locking (FCL), lengthening the bridging plate, or dynamizing the plate with active plates. The FCL method, which changes the axial load with the more parallel interfragmentary method and provides progressive symmetrical mineralization of the callus tissue, is based on the principle that a system that works like an external fixator but works as an internal fixator.

It is thought that this method, which can be defined biomechanically in this way, can prevent the formation of insufficient callus, which may occur especially between plate and bone, in the treatment of periarticular fractures. However, studies on this subject are insufficient in number. Therefore, we aimed to compare the radiological and clinical results of two different diaphyseal fixation models that we performed in the treatment of extra-articular distal tibial metaphyseal fractures with the MIPO method. Our hypothesis is that fixation with the FCL method will provide faster complete union compared to the classical locking plate technique, where the diaphyseal fixation is fixed at all three points with locking screws.

Inclusion criteria

• closed extra articular AO 43A1-3 distal tibial fractures
• Skeletally mature patients
• giving informed consent
• competent neurological and vascular status

Exclusion criteria

• open fractures
• intraarticular extension,
• pathological fractures
• with poor medical health
• patients with deep abrasion or extensive skin contusion and crush injury preventing one-satge MIPPO