Proximal humerus fractures are common injuries, especially among older osteoporotic women. Restoration of function requires a thorough understanding of the neurovascular, musculotendinous, and bony anatomy. This paper addresses the relevant anatomy and highlights various management options, including indication for arthroplasty. In the vast majority of cases, proximal humerus fractures may be treated nonoperatively. In the case of displaced fractures, when surgical intervention may be pursued, numerous constructs have been investigated. Of these, the proximal humerus locking plate is the most widely used. Arthroplasty is generally reserved for comminuted 4-part fractures, head-split fractures, or fractures with significant underlying arthritic changes. Reverse total shoulder arthroplasty is reserved for patients with a deficient rotator cuff, or highly comminuted tuberosities.
Proximal humerus fractures are commonly encountered fractures in general orthopaedic practices. Treatment should focus on maximizing a patient’s functional outcome and minimizing pain. Understanding the functional anatomy of the proximal humerus as it relates to fracture is paramount to achieving these goals. Intervention options range from nonoperative modalities to osteosynthesis, and in select cases arthroplasty. This paper will review relevant anatomy, common fixation constructs, appropriate indications for prosthetic replacement, and the authors’ preferred treatment algorithm.
The glenohumeral joint is the most mobile joint in the body, resulting from a series of complex interactions among bone, muscle, and soft tissue forces. An appreciation for this anatomy enables the surgeon to effectively restore function in the setting of fracture.
The proximal humerus includes the humeral head, greater tuberosity, lesser tuberosity, and the humeral shaft. In the sagittal plane, the humeral head is retroverted an average of 30 degrees relative to the humeral shaft [
In neutral rotation, the greater tuberosity forms the lateral border of the proximal humerus. The lesser tuberosity, which sits directly anterior in this position, becomes profiled medially when the humerus is internally rotated—this creates a rounded silhouette “lightbulb sign” on radiograph. The long head of the biceps passes between the two tuberosities in the intertubercular groove, approximately 1 cm lateral to the midline of the humerus, and its relationship is an important landmark during fracture reduction [
When fractured, the greater and lesser tuberosities are deformed by their musculotendinous rotator cuff attachments (Figure
This drawing demonstrates the deforming forces on the proximal humerus in the setting of fracture. The supraspinatus (A) exerts a force posteromedially. The infraspinatus and teres minor (B) pull posteromedially and externally rotate. The subscapularis (C) exerts an anteromedially directed force on the lesser tuberosity. The pectoralis major (D) internally rotates and adducts, while the deltoid (E) pulls superiorly on the metadiaphysis of the humerus. (Reprinted with permission from Gruson et al. [
The supraspinatus muscle, innervated by the suprascapular nerve, attaches to the superior facet of the greater tuberosity with a force vector that pulls predominantly in a medial direction. The infraspinatus muscle, also innervated by the suprascapular nerve, inserts on the middle facet of the greater tuberosity. The teres minor muscle, innervated by the axillary nerve, attaches to the inferior facet. Together, these three externally rotate and yield a posteromedially directed deforming force. Therefore, if the greater tuberosity is fractured, it is displaced posteromedially. If it remains intact, and there is a surgical neck fracture, the resulting deformity is typically varus and external rotation. Anteriorly, the subscapularis, innervated by the upper and lower subscapular nerves, attaches to the lesser tuberosity, resulting in anteromedial displacement of this osseous fragment if fractured [
The average distance from the pectoralis major tendon (PMT) insertion to the tangent to the humeral head is 5.6 cm. (Reprinted with permission from Murachovsky et al. [
Torrens and colleagues confirmed this relationship and added that hemiarthroplasty rotation could also be estimated based on the insertion of this tendon [
Humeral head vascularity comes from the anterior and posterior humeral circumflex arteries. The anterior humeral circumflex artery (AHCA) runs with its two venae comunicantes as the “three sisters” before anastomosing with the posterior humeral circumflex artery (PHCA). The AHCA gives off an anterolateral ascending branch that crosses the subscapularis tendon anteriorly and runs superiorly along the lateral border of the intertubercular groove before terminating as the arcuate artery [
The PHCA runs posteriorly along with the axillary nerve through the quadrangular space, defined by the subscapularis and teres minor muscles superiorly, the teres major inferiorly, the long head of the triceps medially, and the humeral surgical neck laterally [
Classically, the AHCA has been considered the most important blood supply to the proximal humerus, with secondary contributions from the PHCA and muscular attachments of the proximal humerus [
The anterior humeral circumflex is seen adherent to the proximal humerus (a), whereas the posterior humeral circumflex artery (PCA) seen in (b) is less adherent with several perforating branches along its course, making this vessel less vulnerable to injury in the case of proximal humerus fracture. (Reprinted with permission from Hettrich [
The axillary nerve is the most frequently injured nerve in proximal humerus fractures, and the suprascapular nerve is the second most commonly injured [
The axillary neurovascular structure (AN) can be palpated as a cordlike structure within the anterior deltoid raphe located an average of 3.5 cm from the greater tuberosity (GT) prominence or 6 cm from the anterolateral (AL) border of the acromion, the latter of which is more reliable in the setting of proximal humerus fracture.
The suprascapular nerve runs posteroinferiorly through the suprascapular notch to supply the supraspinatus and infraspinatus muscles. The motor branch of the nerve arises about 1 cm from the base of the scapular spine and courses 2 mm posterior to the glenoid rim [
Evaluation of a proximal humerus fracture begins with a thorough history and physical examination. While one may focus attention on the shoulder, it is important to consider associated injuries and concomitant pathology of the shoulder girdle, upper extremity, and cervical spine. The most common mechanism is a fall from standing in an elderly, osteoporotic woman [
The patient’s baseline level of function, hand dominance, functional demand, and ability to participate in rehabilitation must be assessed as these factors contribute to clinical management decisions. Patients with proximal humerus fractures commonly present with a swollen, ecchymotic shoulder with pain and limited range of motion. The skin should be inspected for associated lesions, ecchymosis, and prior surgical scars. Gross deformity may indicate glenohumeral dislocation. A diligent neurovascular exam is crucial, with particular attention paid to axillary nerve function. Although rare, acute neurovascular compromise may indicate the need for emergent surgical intervention, especially in high-energy injures [
The trauma series of the shoulder consists of three set views: true AP, the lateral or scapular-Y, and axillary views. These allow for adequate evaluation of fracture anatomy, comminution, and fragment displacement. The true AP radiograph is taken perpendicular to the glenohumeral joint by angling the beam 40 degrees away from midline to account for scapulothoracic and glenoid version. The axillary view provides an accurate view of the glenohumeral relationship and is critical to confirm location of the humeral head. Alternatively, in patients who are unable to tolerate this view secondary to pain, a Valpeau view may be substituted. Computed tomography (CT) is a very useful imaging modality. It is helpful for surgical planning as it allows improved delineation of fracture displacement, assessment of comminution, and evaluation of the articular surface [
Radiograph (a) of a proximal humerus fracture. The CT scan with 3D reconstruction (b) adds significant detail and aids in preoperative planning. Osteosynthesis was carried out (c) with the use of intramedullary fibulas (asterisks) and particular attention paid to restoration of the medial calcar (arrow).
The AO classification for proximal humerus fractures was initially described by Muller in 1988 and divides the fracture patterns into the classic 27 subgroups based on the location, type, and severity of the fracture [
Nondisplaced and minimally displaced fractures may be treated conservatively. Following two weeks of sling immobilization, passive motion of the shoulder commences. Shorter periods of immobilization are associated with lower pain scores in the short term; however, at 6 months, there was no difference [
The literature supports good to excellent outcomes for nonoperative management of these minimally displaced fractures in the elderly population. Particularly with regard to valgus impacted fracture patterns, 80% of patients report good to excellent outcomes. Further, patients regained approximately 80% of the abduction and flexion strength compared with the contralateral extremity [
In a subset of patients, elderly, low demand, or those with significant medical comorbidities, even more complex fractures patterns may be treated without surgery. Outcomes in nonoperatively managed 3- and 4-part fractures found that age was the most significant factor influencing outcomes, and no significant correlation was found based on fracture pattern or even radiographic outcomes after union [
Percutaneous pinning is a minimally invasive technique with limited indications. Amenable fracture patterns include 2-part proximal humerus fractures, ideally of the surgical neck, and 3- or 4-part fractures with adequate bone stock [
Better outcomes are reported using percutaneous fixation in patients with good bone quality, an intact medial calcar, lack of proximal shaft comminution, and stable fixation under dynamic fluoroscopy [
Intramedullary devices can be used for fixation of 2-, 3-, and 4-part fractures. Most successful outcomes occur in 2-part fractures. Intramedullary nail fixation with indirect reduction has the benefit of decreased soft tissue stripping. A retrospective review of 2-, 3-, and 4-part fractures treated with a Polarus nail reported that lateral metaphyseal comminution and a lateralized starting point into the greater tuberosity increased the risk of fixation failure [
At our institution, intramedullary nailing of proximal humerus fractures is rarely indicated. However, Konrad et al. have shown equivalent outcomes with plate compared with nail fixation of three-part proximal humerus fractures [
Osteosynthesis is indicated for 2-, 3-, and 4- part fractures in appropriate patients. Exceptions include some 4-part fractures, head-splitting fractures, and fracture-dislocations, which are indicated for prosthetic replacement. While plate fixation has been shown to have superior patient outcome scores when compared with nonoperative treatment in elderly patients, a recent randomized controlled trial showed better radiographic outcomes for plate fixation but equivalent functional outcomes in three- and four-part fractures [
Indications for open reduction internal fixation techniques of proximal humerus fractures have expanded with the introduction of locking plate technology. Initial data on specific locked fixation devices such as the PHILOS plate nearly eliminated complications due to hardware failure and subacromial impingement with good functional outcomes if correct surgical technique is employed. Constant scores in the long term for patients fixed with locked plates range from 70 to 76 [
The majority of complications seen in locked plating are related to surgical technique. The surgeon must therefore restore the medial calcar, avoid a varus malreduction, and prevent screw penetration to ensure best outcomes, decreasing revision rates and loss of fixation [
Optimal management of 4-part proximal humerus fractures is most controversial. A systematic review of the available evidence-based literature was inconclusive with regard to arthroplasty versus internal fixation for these fractures [
Arthroplasty for proximal humerus fractures is a good surgical option for low-demand elderly patients, or fractures that are not amenable to ORIF. Significant controversy exists as to the best surgical intervention for 3- or 4-part fractures in the elderly osteoporotic patient. As previously noted, 4-part valgus impacted fractures have a lower rate of osteonecrosis due to preservation of blood supply and may be more amenable to fixation compared with displaced 4-part fractures [
It is also important to consider the degree of underlying shoulder pathology, including symptomatic glenohumeral osteoarthritis, or rotator cuff arthropathy. If present, these could potentially predispose a patient to poor outcomes following osteosynthesis. Thus, the presence of osteoarthritis or rotator cuff pathology should influence the surgeon’s choice away from ORIF and towards arthroplasty (either hemiarthroplasty or reverse total shoulder arthroplasty).
Anatomic tuberosity healing enables a functional rotator cuff and is critical for patient satisfaction and functional outcomes following hemiarthroplasty. Boileau et al. [
There is debate in the literature as to hemiarthroplasty versus reverse total shoulder arthroplasty for acute proximal humerus fractures. Currently, indications for a reverse total shoulder arthroplasty in proximal humerus fracture are limited to rotator cuff deficiency and severe tuberosity comminution. Recently, outcomes data comparing hemiarthroplasty with reverse total shoulder arthroplasty for acute proximal humerus fractures showed superior function in patients who underwent reverse total shoulder arthroplasty [
Another important consideration is timing to intervention. Arthroplasty within the first 4 weeks following injury yields superior functional results when compared with delayed procedures or procedures for malunion [
As discussed ealier, intervention ranges from nonoperative treatment to osteosynthesis and arthroplasty. Our treatment algorithm is based upon both chronological age as well as physiologic age (Figure
Treatment algorithm for proximal humerus is based on patients chronological and physiological age. Young patients are treated more aggressively with osteosynthesis making every attempt to restore normal anatomy, while the older patient may benefit from an array of treatments ranging from nonoperative to prosthetic replacement.
Patients under the age of 50 should receive every effort to restore normal anatomy including those high-risk fracture patterns such as 4-part and some head splits or fracture-dislocations. Elderly patients are those over 70 years of age. These patients benefit from osteosynthesis of 2- and 3-part and some 4-part proximal humerus fractures. The majority of 4-part fractures, head splits, and fracture-dislocations should be treated with prosthetic replacement in this group. Patients aged 50 to 70 years represent a gray area. That is, patients who are physiologically young may be treated more aggressively with osteosynthesis. Conversely, the physiologically elderly should be treated as such.
If arthroplasty is to be employed, the decision between hemiarthroplasty and reverse total shoulder arthroplasty is based upon several factors (Figure
In patients indicated for prosthetic replacement, it is important to consider rotator cuff competency and risk of tuberosity nonunion. Patient with high risk of tuberosity nonunion (severe comminution, diabetes, smoking, or peripheral vascular disease) may benefit from primary reverse total shoulder arthroplasty.
Hemiarthroplasty requires an intact rotator cuff (or repairable rotator cuff) and tuberosities with a high likelihood of healing. Reverse total shoulder arthroplasty should be considered in patients with an irreparable rotator cuff, comminuted tuberosities, and those with comorbidities (diabetes, smoking, or peripheral vascular disease) that put them at risk for tuberosity nonunion.
Proximal humerus fractures are common injuries, especially among older osteoporotic women. Restoration of function requires a thorough understanding of the neurovascular, musculotendinous, and bony anatomy. In the vast majority of cases, proximal humerus fractures may be treated nonoperatively. In displaced fractures, however, surgical intervention may be pursued. While numerous constructs have been investigated, the proximal humerus locking plate is most widely used and effective. In our experience, with proper restoration of the medial calcar, even 3- and 4-part proximal humerus fractures may be effectively treated with ORIF. Arthroplasty is reserved for fractures that cannot be reconstructed, such as comminuted 4-part fractures, head-split fractures, or fractures with significant underlying arthritic changes. Reverse total shoulder arthroplasty is reserved for patients with a deficient rotator cuff, or highly comminuted tuberosities.