New, Minimally Approach for Middle and Distal Third Humeral Shaft Fractures a Cadaveric Study and Clinical Case Series

Purpose: Fractures of the humeral shaft, especially the treatment of extraarticular fractures of the distal third of the humerus, which is a challenge. We hypothesize that a new feasibility and safety minimally invasive surgical approach can be used for the treatment of middle-and distal-third humeral fractures. The main purpose of this study was to evaluate this new approach and develop it. Methods: In 13 adult cadaver arms, a minimally invasive surgical approach to the anteromedial humerus was simulated, followed by fixation with a locking compression plate and the measurement of several sets of anatomical data to clarify the possible risk of iatrogenic vascular and nerve injury in this surgical approach. Between 2017 and 2019 in 18 patients with humeral fractures who were treated with this surgical approach. Results: Patients were followed for average 20.1 months (range, 15 – 34 months). The distance from the vertex of the medial epicondyle to the median nerve was 2.96 cm (range, 2.30 – 3.40 cm). The distance from the tip of the distal end of the screw in the medial epicondyle to the ulnar nerve was 1.7 mm (range, 0.00 – 4.00 mm). The shortest distance between the Olecranon Fossa and the tip of the screws at the distal end of the plate in the medial humeral epicondyle was 0.69 mm (range, 0.00 – 7.00 mm). The distance from the vertex of the epicondyle to the intersection of the median nerve and the distal end of the underlying steel plate was 6.28 cm (range, 5.70 – 6.90 cm). Conclusions: This approach does not cause iatrogenic neurovascular injury and provides sufficient strength for the fixation of fractures of the middle and distal thirds of the humerus. This approach can be used as an alternative in the treatment of extraarticular fractures of the middle and distal thirds of the humerus. Type of study/level of evidence Therapeutic Level IV.