Elbow Soft Tissue Apex as a Marker for the Anterior Humeral Line: An Anatomic Landmark for Pinning of Pediatric...

Three-dimensional awareness of humeral anatomy is paramount to the successful percutaneous pinning of pediatric supracondylar humerus fractures. Technical tips and anatomic landmarks can help residents develop basic surgical skills and understand the humerus's position within the soft tissue envelope. For patients with an extension-type supracondylar humerus fracture, the soft tissue apex of the elbow in full flexion (∼130°) serves as an anatomic correlate for the anterior humeral line. This novel anatomic landmark can assist trainees in visualizing the humeral shaft, estimating the pin placement angle, and achieving adequate fracture fixation.

A single-institution electronic medical record was reviewed for supracondylar humerus fracture fixation within the past two years. Fluoroscopic series were reviewed for reduction laterals. Injury films were reviewed for humeral measurements and fluoroscopic calibration. A line along the axis of the anterior humeral cortex was drawn through the soft tissue shadow on the reduction lateral and the distance from the line's intersection through the skin and the soft tissue apex was measured.

Thirty-two patients were studied, comprising 17 males and 15 females, with a mean age of 6.6 years (SD ± 1.69 years). Fractures were classified using the Gartland classification, with 16 classified as type II and 16 as type III. The average lateral cortical width measured 12.8 mm (SD ± 1.79 mm), while the intramedullary width averaged 7.4 mm (SD ± 1.23 mm). The mean distance between the soft tissue apex and the anterior humeral cortex was 0.85 mm (SD ± 1.09 mm).

The soft tissue apex of the elbow is a reliable landmark for the anterior humeral cortex, providing trainees with an intuitive and easily visualized reference for guiding pin placement. Utilization of this technique can enhance intraoperative efficiency and precision, making it a valuable tool to have in surgeon's armamentarium.

(1)While supracondylar humerus fractures are amongst the most common operative pediatric injuries, orthopaedic residents perform an average of only 19 of these cases during their training.(2)Identification of reproducible landmarks enhances outcomes, improves autonomy, and reduces fluoroscopy utilization, particularly for residents and early-career surgeons.(3)The soft tissue apex of the elbow serves as a reliable landmark for the anterior humeral cortex, regardless of patient age or BMI.

IV - Case series with no comparison group.