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

Abstract

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 followup (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 scapulaetrochanter). 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. Introduction Humeral shaft fractures account for approximately 3% of all orthopaedic injuries.1 Most of the humeral shaft fractures can be treated nonoperatively: studies in literature reported excellent results with high rates of bone union and functionally and aesthetically acceptable residual deformities.1-3 Operative treatment has gained popularity for displaced, open or pathological fractures, fractures of the proximal or distal third of the shaft and fractures with ipsilateral brachial plexus or vascular injuries, and several options exist based on bone quality, type of fracture, its location, associated soft tissue injuries.1,4 Proximal and middle one-third diaphyseal humeral fractures, instead, are barely described in literature and controversies exist about the ideal treatment. Studies analyzing the intramedullary nail technique showed a higher risk of fixation failure in comminuted and osteoporotic bones and in fractures extending into the tuberosity or metaphysis;5,6 moreover, some clinical series reported debilitating shoulder complications due to nail insertion through the rotator cuff.1,4 Alternatively, locking plate fixation in humeral fractures has spread given its less amount of interference with elbow and shoulder function, rapid functional recovery and its stable fixation.5 However, in proximal and middle third diaphyseal fractures plates have some limitations:5 the radial nerve is at risk during the surgical approach at the middle diaphysis and detachment of the deltoid from its tuberosity is a common maneuver to accommodate the plate adequately, but it may slow functional recovery.7,8 The iatrogenic radial nerve injury is described in about 7% of cases (2.7%-20%),9 secondary to intraoperative traction rather than direct plating compression; this susceptibility is due to its fixed position in the sulcus radialis and its direct contact with the periosteum of the humerus after passing the medial intermuscular septum. Regarding the deltoid detachment, in the past some authors have proposed manually twisting straight plates to avoid the deltoid insertion: despite satisfied results, it is unknown to what extent the twisting weaken the plate, and the twisted head may accommodate fewer screws for the humeral head.7-11 Other reports describe the application of helical plates on the humerus originally designed for other anatomical areas.5 The literature that deals with helical plates is however scarce. With our study we describe our experience using helical plates specifically designed for the humerus (A.L.P.S.® Proximal Humeral Plating System, Zimmer Biomet) for managing proximal and middle one-third diaphyseal fractures, reporting clinical evaluation of patients based on the range of motion measurement, DASH Questionnaire and Constant score. Material and Methods From 2019 to 2021, we have evaluated a consecutive series of patients who were admitted to our institution for humeral fractures involving the proximal third diaphysis and caused by high energy traumas or falls. [Surgical Techniques Development 2021; 10:9175] [page 1] Surgical Techniques Development 2021; volume 10:9175 Giulia Nicolaci, Department of Orthopaedics and Traumatology, Università degli Studi di Torino, Via Gianfranco Zuretti 29, 10126 Torino, Italy. E-mail: [email protected]