Purpose: Several authors have described methods to predict the sural nerve pathway with non‐proportional numerical distances, but none have proposed a person‐proportional, reproducible method with anatomical references. The aim of this research is to describe ultrasonographically the distance and crossing zone between a surface reference line and the position of the sural nerve.Methods: Descriptive cross‐sectional study, performed between January and April 2022 in patients requiring foot surgery who met inclusion criteria. The sural nerve course in the posterior leg was located and marked using ultrasound. Landmarks were drawn with a straight line from the medial femoral condyle to the tip of the fibula. Four equal zones were established in the leg by subdividing the distal half of the line. This way, areas based on simple anatomical proportions for each patient were studied. The distance between the marking and the ultrasound nerve position was measured in these 4 zones, creating intersection points and safety areas. Location and distances from the sural nerve to the proposed landmarks were assessed.Results: One‐hundred and four lower limbs, 52 left and 52 right, assessed in 52 patients were included. The shortest median distance of the nerve passage was 2.9 mm from Point 2. The sural nerve intersection was 60/104 (57.7%) in Zone B, 21/104 (20.1%) in Zone C and 19/104 (18.3%) in Zone A. Safety zones were established. Average 80.5% of coincidence in sural nerve localization was found in the distal half of the leg, in relation to the surface reference line when comparing both legs of each patient.Conclusions: This study proposes a simple, reproducible, non‐invasive and, for the first time, person‐proportional method, that describes the distance and location of the main areas of intersection of the sural nerve with points and zones (risk and safe zones) determined by a line guided by superficial anatomical landmarks. Its application when surgeons plan and perform posterior leg approaches will help to avoid iatrogenic nerve injuries.Level of evidence: IV.

Background: Tibiotalocalcaneal (TTC) arthrodesis is a procedure commonly used as salvage surgery for various pathologic processes that compromise the ankle and subtalar joints. It is a reasonably standardized procedure when performed as a primary surgery in advanced stages of TTC arthritis. For such cases, there are several alternative approaches, fixation materials, and bone substitutes that can be used. Most represent valid options with similar results in the literature. However, in highly complex cases requiring TTC arthrodesis, the options for the approach and fixation material can be limited. Understanding the alternative approaches and techniques is of great help to the surgeon when faced with highly complex cases, such as patients with multiple previous operations, lack of bone stock, severe deformities, or compromise of associated soft tissues. In this article, we describe the role of the posterior approach with some technical variation that allows extra-articular arthrodesis in highly complex cases, and we present a series of patients with tibiotalocalcaneal arthrodesis who were operated on using this technique. Methods: Retrospective review of all patients who underwent tibiotalocalcaneal arthrodesis via posterior approach between 2008 and 2016. The surgeries were performed by 2 different surgeons with the same technique (posterior approach with sliding graft) but 2 different fixation methods. Radiographs and computed tomographic (CT) studies were reviewed and patient satisfaction was rated using the Coughlin scale. Mean follow-up was 38 months. We identified 20 patients. The mean age was 51.2 years; 11 patients had post-traumatic arthritis whereas the others had other causes of arthritis (inflammatory disease, neurologic deformity, etc). Results: The arthrodesis was performed using a tibiotalocalcaneal plate in 9 patients and retrograde intramedullary nail in 11 patients. Radiographic fusion was observed at an average of 3.1 months. Four patients had complications and 15 reported good or excellent results after surgery. Conclusion: Our study found a fusion rate comparable to other studies in highly complex cases. There were no operative wound complications. We observed that the posterior approach, with an extra-articular fusion procedure, was a valid option for salvage surgery in highly complex cases that require tibiotalocalcaneal fusion. Level of Evidence: Level IV, retrospective case series.