How to treat proximal and middle one-third humeral shaft fractures: The role of helical plates

Complex proximal third diaphyseal humeral fractures are uncommon patterns of injury mainly caused by high energy trauma. The anatomical shape of the humerus, the presence of the deltoid tuberosity and the close proximity of the radial nerve into the radial groove represent challenge elements to deal with. Historically, straight plates were manually twisted; subsequently, helical plates created for other anatomical sites (as distal tibia) were used in humeral fractures. In both these experiences surgeons observed several disadvantages. More recently, dedicated helical plates have been created. In this study, we expose our surgical technique for using helical humeral plates (A.L.P.S.® Proximal Humeral Plating System, Zimmer Biomet), with its advantages and operative recommendation.

From 2019 to 2021, nine patients who were admitted to our institution for humeral fractures involving the proximal third diaphysis have been treated with humeral helical plates. At one and six months after surgery, standard antero-posterior and lateral radiographs were obtained, and at last follow-up (fourteen months on average) clinical evaluation was performed through range of motion assessment, Constant score and DASH score questionnaires. At six months, all fractures have healed. At last follow-up (fourteen months on average, 6-22) the average range of motion were flexion 135° (90°-180°); abduction 124° (85°-180°); external rotation 52° (20°-80°), internal rotation at L3 (between scapulae-trochanter). Average Constant Shoulder Score was 70 (33-96), average Dash score was 21 (range 1,7-63). Three patients experienced temporary radial nerve palsy from injury, with subsequently improvement at EMG analysis within eight months from surgery. In our opinion this strategy avoids the deltoid tuberosity and reduces the risk of radial nerve injury, increasing the possibility of a rapid functional recovery after surgery.