Proximal Humerus Fractures

Surena Namdari, MD, MSc

Gerald R. Williams Jr, MD

Dr. Namdari or an immediate family member has received royalties from DJ Orthopaedics and Miami Device Solutions; is a member of a speakers’ bureau or has made paid presentations on behalf of DJ Orthopaedics; serves as a paid consultant to DJ Orthopaedics, Integra Life Sciences, and Miami Device Solutions; has received research or institutional support from Arthrex, Integra, and Zimmer; has received nonincome support (such as equipment or services), commercially derived honoraria, or other non-research–related funding (such as paid travel) from Saunders/Mosby-Elsevier; and serves as a board member, owner, officer, or committee member of the American Journal of Orthopedics and the Bone & Joint 360. Dr. Williams or an immediate family member has received royalties from DePuy, A Johnson & Johnson Company, DJ Orthopaedics, and IMDS; has stock or stock options held in CrossCurrent Business Analytics, Force Therapeutics, For MD, In Vivo Therapeutics, and OBERD; has received research or institutional support from DePuy, A Johnson & Johnson Company, Synthasome, and Tornier; and has received nonincome support (such as equipment or services), commercially derived honoraria, or other non-research–related funding (such as paid travel) from Wolters Kluwer Health–Lippincott Williams & Wilkins.

Introduction

Fractures of the proximal humerus are relatively common injuries, accounting for 5% of all fractures. The incidence increases rapidly with age, with more than 70% of proximal humerus fractures occurring in patients older than 60 years of age. Upper extremity fractures can considerably limit independence and function in an elderly individual, and may lead to a permanent move to a nursing home in 6% of patients. The male-to-female gender ratio for proximal humerus fractures has been estimated at 3:7. Approximately 20% to 50% of proximal humerus fractures are displaced or unstable. Given the risks of malunion and nonunion, the preference in unstable fracture patterns is for surgical intervention to reduce fracture fragments and generate the stability necessary for early motion. Despite this, nonoperative treatment for displaced fractures may be indicated for low-demand or medically debilitated patients. Some patients who undergo nonoperative treatment of a displaced proximal humerus fracture can achieve satisfactory pain relief and very functional results; however, the results may be less predictable than anatomic reconstruction.

While many options for fixation exist, the selected treatment must be able to withstand the loads placed on the proximal humerus while motion is initiated and fracture healing is taking place. The rotator cuff, deltoid, pectoralis major, latissimus, and teres major muscles invoke substantial deforming forces on the fracture fragments of the proximal humerus. The combination of multiple deforming forces and poor bone quality can lead to complications, including fracture malunion, hardware failure, and a poor clinical result. Possible fixation techniques include locked plating, percutaneous fixation with screws and pins, intramedullary nailing, and external fixation. Hemiarthroplasty and reverse arthroplasty are both used as treatment options for proximal humerus fractures that are not amenable to nonoperative treatment or surgical fixation. Arthroplasty can be technically challenging, requiring anatomic placement of the prosthesis and anatomic healing of the tuberosities to achieve an optimal functional result. Rehabilitation following surgical management of the proximal humerus is similar, regardless of the type of surgical procedure, and is dependent on achieving stable fixation. In this chapter, we will discuss the surgical treatment of proximal humerus fractures with an emphasis on surgical details that facilitate rehabilitation.

Surgical Procedures

Locked Plate Fixation

Indications

Locked plating can be utilized for all fractures that meet the indications for operative treatment as outlined by Neer (angulation of the articular surface of >45° or displacement of >1 cm between the major fracture segments) or are unstable. Locked plating provides for enhanced axial stability of the fracture fixation. The determination of whether a fracture is amenable to surgical fixation or is better suited for arthroplasty is controversial and based on multiple variables, including age, activity level, bone quality, comminution, and
fracture displacement. In general, locked plating is indicated in two-part surgical neck fractures (especially those with medial comminution), three-part fractures, and selected four-part fractures (patients under the age of 50). Minimally invasive osteosynthesis techniques, such as percutaneous pin or screw fixation, are less rigid forms of fixation and are not generally performed in cases of substantial calcar comminution or fracture displacement.

Procedure

A deltopectoral or anterolateral (deltoid-split) exposure can be used to expose the proximal humerus. In both procedures, we routinely identify and protect the axillary nerve. Rehabilitation protocol is not affected by the approach utilized. We prefer a deltopectoral approach. After development of the deltopectoral interval, the biceps is routinely tenodesed to the upper border of the pectoralis major and is resected proximal to this tenodesis site. Heavy nonabsorbable sutures are placed in the subscapularis, supraspinatus, and infraspinatus tendons at the myotendinous junction to control fracture fragments. Sutures are placed in the stronger rotator cuff tendons rather than through the soft bone of the tuberosities to improve fixation strength. Secure tuberosity fixation is among the most important factors that allow early rehabilitation. A low-profile proximal humeral locking plate with angular stable locking screws and suture eyelets is selected to provide fracture fixation (Figure 10.1). A provisional reduction of the surgical neck and humeral head fragment can be obtained using blunt elevators or joysticks and held with Kirschner wires. The tuberosities are reduced via the traction sutures with minimal manipulation and impaction of the cancellous bone underlying the tuberosities. The plate is secured to the humeral head and/or the shaft using Kirschner wires. The initial screw should be diaphyseal, bicortical, and nonlocking. This allows compression of the plate against the humeral shaft and allows subsequent reduction of the tuberosities to the shaft via the plate. It is critical not to reduce a fracture in internal rotation, as this will limit the patient’s ability to regain functional external rotation postoperatively. To ensure that this does not occur, reduction and plating are performed with the arm in 30° of external rotation. In addition, the biceps groove can be identified in the proximal fragment and in the distal shaft, and can be used as a guide to reduction alignment. Plate height should be confirmed fluoroscopically so that the plate is not too proximal to impinge with shoulder abduction. Similarly, if using a plate with fixed-angled locking screws, accurate plate position ensures the correct location and trajectory for the inferior humeral head screw(s), which is critical to the stability of the construct. Once plate position is confirmed, fixation into the head is performed with five or more locking screws. Care is taken to avoid intra-articular screw penetration. In general, three nonlocking, bicortical screws are placed in the humeral shaft. Finally, separate tuberosity sutures are passed through the plate eyelets and tied. Ideally, a superior suture is placed for the supraspinatus tendon, an anterior suture for the subscapularis, and a posterior suture for the infraspinatus tendon. The augmentation of fixation constructs with intramedullary fibular grafts, calcium phosphate or sulfate cement, and/or cancellous bone chips is determined subjectively at the time of the procedure and is dictated primarily by the bone quality. Multiple fluoroscopic views are utilized to ensure that screws have not violated the glenohumeral joint.

Figure 10.1 Illustration of low-profile proximal humeral locking plate (Miami Device Solutions, Miami, FL) with angular stable locking screws and suture eyelets (red arrow).

Complications

Complications of proximal humeral locking plate fixation include malreduction, intra-articular screw penetration, primary screw cutout and loss of reduction, malunion, nonunion, avascular necrosis, and infection. A typical failure mode involves loss of fixation in the humeral head, varus collapse of the head fragment, and screw cutout (Figure 10.2). Screw cutout and intra-articular screw penetration can result in rapid glenoid destruction and need for arthroplasty. Excessive superior plate placement can result in pain and motion limitation from acromial impingement. Alternatively, excessively inferior plate placement can result in inadequate fixation in the humeral head and/or ineffective buttress fixation of the greater tuberosity fragment. Overly aggressive rehabilitation may result in fixation failure. Therefore, the timing and intensity of rehabilitation should be adjusted based on bone quality and stability of fixation.

Arthroplasty

Indications

Arthroplasty is indicated in proximal humerus fractures that are not amenable to surgical fixation. This includes certain three-part and four-part fractures, fracture-dislocations, and head-splitting fractures. The decision to proceed with arthroplasty is dependent on multiple patient-specific and
fracture-specific factors, including patient age, activity level, medical comorbidities, expectations of treatment, fracture pattern, displacement, bone quality, comminution, and chronicity of the injury. Indications for reverse arthroplasty versus hemiarthroplasty are controversial. In general, reverse arthroplasty is indicated in selected patients over the age of 70 or in patients younger than 70 with pre-existing rotator cuff tears, extreme tuberosity comminution, or poor bone quality. Although the popularity of hemiarthroplasty has decreased as the use of reverse arthroplasty has increased, there remains a role for hemiarthroplasty in younger patients (over 50 and under 70 years of age) whose fractures cannot be reduced and fixed adequately (Figure 10.3).

Figure 10.2 Plain radiograph of example of a failed proximal humerus ORIF with varus collapse of the head segment and screw cutout.

Figure 10.3 A, Plain radiograph of proximal humerus fracture with displacement of the greater tuberosity, lesser tuberosity, and impaction of the humeral head. B, Plain radiograph of hemiarthroplasty with anatomic reduction of the greater tuberosity fragment.