Proximal Humerus Fracture Case File
Eugene C. Toy, MD, Andrew J. Rosenbaum, MD, Timothy T. Roberts, MD, Joshua S. Dines, MD
CASE 10
A 68-year-old right-hand dominant woman presented to the emergency room with a chief complaint of right shoulder pain and loss of motion. Earlier that morning, she sustained a mechanical fall onto her right side after slipping on a patch of ice. She denied any head strike or loss of consciousness and denied pain besides that in her right shoulder. Her past medical history is remarkable for osteoporosis and hyperlipidemia. She did sustain a left wrist fracture 5 years earlier, which was treated with a cast. She currently takes alendronate and simvastatin. She has no past surgical history. On examination, she appears in pain. Her vital signs are within normal limits. She has significant ecchymosis of her right upper arm. Her sensation is intact in her right arm within the radial, ulnar, median, and axillary nerve distributions. She has 5/5 strength in her biceps, triceps, wrist flexors, wrist extensors, and all finger flexors and extensors, as well as the interossei muscles. She is unable to forward flex or abduct her right shoulder. She has significant pain with any passive range of motion of the shoulder. The remainder of her exam is within normal limits. A single portable radiograph is obtained of the right shoulder and is shown in Figure 10–1 .
Figure 10–1. Single portable radiograph of the right shoulder.
► What is your most likely diagnosis?
► What is your next diagnostic step?
► What is the next step in therapy?
ANSWER TO CASE 10:
Proximal Humerus Fracture
Summary: A 68-year-old woman with a history of osteoporosis and previous fragility fracture presents with acute-onset right shoulder pain after a mechanical fall. Her exam is remarkable for an ecchymotic right arm and the inability to move her right shoulder due to pain. She is neurovascularly intact distally.
- Most likely diagnosis: The most likely diagnosis is a fracture of the proximal humerus. Other diagnostic considerations for acute shoulder pain following trauma includes fractures of the shoulder girdle (clavicle, scapula), glenohumeral dislocation (aka shoulder dislocation), acromioclavicular dislocation (aka shoulder separation), and acute rotator cuff tear.
- Next diagnostic step: The next step in diagnosis requires appropriate plain radiographic imaging of the right shoulder to confirm the exact fracture pattern and exclude other injuries including glenohumeral dislocation. This should include at a minimum an anteroposterior view, a scapular Y view and an axillary view. It is critical to obtain an acceptable axillary view in order to rule out dislocation of the glenohumeral joint. Based on the AP radiograph presented, this is a valgus impacted, three part proximal humerus fracture with displacement of the greater tuberosity and humeral head.
- Next step in therapy: Sling immobilization of the right shoulder is the next step with consideration of operative treatment depending on the amount of displacement.
ANALYSIS
Objectives
- Understand the typical patient demographics and mechanism of injury associated with proximal humerus fractures and understand what constitutes an appropriate workup for this injury.
- Understand the Neer classification and deforming forces for proximal humerus fractures.
- Be familiar with the various treatment options for proximal humerus fractures.
Considerations
This 68-year-old female presented with right shoulder pain and loss of motion following a mechanical fall. The differential diagnosis must include fracture, shoulder dislocation, rotator cuff tear, and/or a combination of these injuries. A thorough physical exam and appropriate imaging studies will help distinguish these conditions. The exam is crucial, as both proximal humerus fractures and shoulder dislocations are associated with nerve injury.
Once exam and imaging confirm the diagnosis of a proximal humerus fracture, the orthopaedic surgeon must decide the appropriate treatment, which includes both nonoperative and operative modalities. The patient’s general condition, functional status, comorbidities, and the specific type of proximal humerus fracture will factor into the clinical decision-making. In the ED, a sling is typically satisfactory for initial stabilization. However, in the setting of a concurrent glenohumeral dislocation, attempts to reduce the humeral head may also be required.
APPROACH TO:
Proximal Humerus Fracture
DEFINITIONS
OSTEOPOROSIS: The most common metabolic bone disease, characterized by a loss in skeletal mass resulting in microarchitectural changes and increasing bone fragility.
PROXIMAL HUMERUS FRACTURE “PART”: Based on the Neer classification of proximal humerus fractures. A proximal humerus is composed of 4 potential parts: the head or articular surface, the greater tuberosity, the lesser tuberosity, and the shaft. To be considered a “part,” each fragment must be displaced at least 1 cm or 45 degrees. Deforming forces are applied to each part as a result of its respective muscular attachments. The greater tuberosity part is displaced by the supraspinatus and infraspinatus pulling it posteromedially, the lesser tuberosity part is displaced by the subscapularis tendon pulling it medially, and the shaft part is typically deformed in an apex anterior and abducted position by the insertions of the deltoid and pectoralis major. NONUNION: Failure of the ends of a fractured bone to heal. Prevalence of nonunion with proximal humerus fractures is approximately 1% but is increased with certain fracture patterns, particularly surgical neck fractures with significant translation.
AVASCULAR NECROSIS: Death of osteocytes secondary to compromised blood supply. Avascular necrosis can occur after proximal humerus fractures if the blood supply to the humeral head has been sufficiently damaged. The head is predominantly supplied by the anterolateral ascending branch of the anterior humeral circumflex artery, but also receives some blood supply from the posterior humeral circumflex. This occurs most commonly after 4-part fractures. Avascular necrosis ultimately results in articular surface collapse and shoulder arthritis, which may require surgical interventions, including shoulder arthroplasty.
CLINICAL APPROACH
Etiologies
Proximal humerus fractures account for 4% to 5% of all fractures. They typically appear in a bimodal distribution; younger patients are typically male, and their fractures are a result of high-energy trauma (including motor vehicle accidents, falls from significant height, or gunshot injuries). Older patients who sustain this injury are much more likely to be postmenopausal women who have experienced a lowenergy mechanism, such as a trip and fall from standing height, like the patient in this case.
Not surprisingly, there is a significant association with osteoporosis and proximal humerus fractures. The loss of trabecular microarchitecture and bone mass causes a significant increase in bone fragility of the humeral head, placing it at risk of fracture even with low-energy trauma. The association of osteoporosis and proximal humerus fractures is supported by the fact that the vast majority of proximal humerus fractures occur in females and individuals older than 50 years. In fact, some studies have shown that proximal humerus fractures more reliably correlate with bone fragility than do spine, hip, or wrist fractures, which are all widely regarded as classical sites of fragility fracture.
An uncommon etiology leading to proximal humerus fracture that must be excluded is malignancy. This may include benign and malignant primary bone tumors, as well as metastatic disease. Compared with nonpathologic fractures, these are extremely rare, but must be recognized if present, as this can drastically change patient management.
Clinical Presentation
Patients with a proximal humerus fracture will present with pain, swelling, and ecchymosis of the involved shoulder. They may or may not be able to move their shoulder depending on the amount of pain they have, which may be a function of how displaced their fracture is (eg, a nondisplaced fracture may be less painful than a 4-part fracture). Typically, patients will cradle the affected arm at their side.
As stated earlier, most patients presenting with a proximal humerus fracture will be older (>50 years old) and are more likely to be female. The most common mechanism is a mechanical fall. Younger patients will likely require a more violent mechanism of injury to sustain a fracture, unless an underlying metabolic bone disease is present. The history should focus on discerning the mechanism of injury and also identifying any risk factors for fracture (history of prior fracture, osteoporosis, corticosteroid use, immunocompromised status, history of malignancy or prior radiation).
Diagnosis
A thorough physical examination is the first step in diagnosis. Discerning a proximal humerus fracture from other bony and soft tissue injuries to the shoulder based on exam alone can be difficult, but some signs might point toward an alternativediagnosis. This includes deformity and crepitus of the clavicle, which would suggest a clavicle fracture, as well as deformity at the acromioclavicular joint, suggesting an acromioclavicular dislocation, or external rotation of the arm, suggesting anterior glenohumeral dislocation. Examining the entire shoulder girdle for wounds indicating an open fracture is mandatory. A good exam also assesses for the presence of a neurovascular injury. Injury to the axillary artery occurs in fewer than 5% of all cases, but is more likely with severe injuries (4-part fractures). An appropriate workup should include assessment of capillary refill and palpation of the radial pulse; Doppler ultrasound and angiography should be used on an as-needed basis when clinical suspicion is sufficiently high. Nerve injuries are also uncommon but possible, as the infraclavicular brachial plexus and peripheral nerve branches lie anteromedial to the humeral head. Nerve injuries are more common with fracture dislocations and fractures involving the surgical neck. An isolated axillary nerve injury is most commonly seen with a greater tuberosity fracture-dislocation as a result of its anatomic proximity. Sensory and motor testing of the axillary nerve (motor = deltoid, sensory = lateral aspect of upper arm), as well as the median (motor = FDP [flexor digitorum profundus] to index, sensory = palmar aspect thumb to half of ring finger), ulnar (motor = interossei, sensory = palmar aspect of small and half of ring finger), and radial (motor = wrist and digit extensors, sensory = dorsal aspect of first webspace) nerves should be routinely undertaken to rule out a neurologic injury.
Plain radiographs are essential to the diagnosis of a proximal humerus fracture. An adequate plain radiographic examination should include an AP, scapular Y, and an axillary view at a minimum ( Figure 10–2 ). Poor or incomplete radiographs should not be tolerated. Advanced imaging may be necessary in certain cases. Computed tomography scans can be helpful in certain circumstances; they may be helpful to better understand the global fracture pattern, determine the amount of tuberosity displacement or tuberosity comminution, or determine the presence of an intraarticular “head splitting” component. Although rotator cuff tears are uncommon in combination with proximal humerus fractures, magnetic resonance imaging can be performed to evaluate the condition of the rotator cuff or any other soft tissues.
The most common classification system in use for proximal humerus fractures is the Neer classification. This system divides the proximal humerus into 4 potential parts. This includes the head (created by a fracture through either the anatomic or surgical neck), the greater tuberosity, the lesser tuberosity, and the shaft. A fragment is considered a “part” if it is displaced greater than 1 cm (0.5 cm if it is the greater tuberosity) or by 45 degrees by its muscular attachments (greater tuberosity = supra and infraspinatus; lesser tuberosity = subscapularis; shaft = pectoralis major and deltoid). Thus a fracture with minimal displacement (regardless of how many fracture lines are present) is considered a 1-part fracture. A 2-part fracture is most commonly an isolated displaced fracture at either the surgical neck or greater tuberosity; much less common 2-part fractures (although possible) include a displaced fracture through the anatomic neck or lesser tuberosity. The most common 3-part fracture involves displaced fractures through both the greater tuberosity and surgical neck. A 4-part fracture involves displacement of both tuberosities, the head and the shaft. Although this classification system is not perfect, it does serve as a means of describing the fracture and providing rough guidelines for treatment.
TREATMENT
After examining the patient, the very first step in treatment is immobilization. This consists of a simple sling or shoulder immobilizer. This enhances patient comfort and may serve as definitive treatment in some cases. If a concomitant glenohumeral dislocation is also present, then prompt closed reduction should be performed as soon as feasible with the assistance of local anesthesia and/or sedation.
A
B
Figure 10–2. (A) Scapular Y and (B) axillary views of the same shoulder shown in Figure 10–1 . This
confirms the presence of a 3-part proximal humerus fracture.
Determining the definitive treatment for a proximal humerus fracture requires careful consideration on a case-by-case basis. Not only must the fracture characteristics be considered, but also the global assessment of the patient. A demented 90-year-old nursing home patient will perhaps require a different treatment plan compared with a healthy 30-year-old, even if their fracture patterns are similar. However, in general, the following treatment algorithm can be used to guide treatment for closed fractures.
One-part fractures → sling for 2 weeks followed by progressive range of motion with close follow-up. This is an appropriate treatment for approximately 80% of all proximal humerus fractures.
Two, 3, and valgus impacted 4-part fractures → open reduction internal fixation (particularly in younger patients). This allows for restoration of the native anatomy and early range of motion. Isolated avulsion fractures of the greater tuberosity with greater than 5-mm displacement should be treated surgically as well because of the risk of malunion leading to subacromial impingement of the displaced greater tuberosity. Of note, percutaneous pinning and intramedullary nailing are other operative interventions less commonly employed.
Fractures with significant risk of AVN (4-part fractures, head-split fractures, displaced anatomic neck fractures in the elderly) → prosthetic replacement with humeral head hemiarthroplasty. This avoids the risk of avascular necrosis and allows for early range of motion.
Open fractures and fractures with associated vascular injury should always be treated operatively with irrigation and debridement, repair of any vascular injury, and then fracture treatment as appropriate given the fracture pattern.
In general, clinical outcomes with open-reduction internal fixation are superior to hemiarthroplasty. Every effort should be made to treat displaced fractures with open reduction internal fixation unless there are a prohibitive amount of risk factors for a poor outcome with this modality (poor bone stock, high risk of AVN, poor nutritional status/healing potential, very low demand patient).
Complications
Stiffness: Loss of motion of the glenohumeral joint is a common occurrence after a proximal humerus fracture. This can occur subsequent to both operative and nonoperative treatment. Shoulder stiffness can be limited by instituting range-of-motion exercises as soon as the fracture pattern permits.
Nonunion: Most common with displaced surgical neck fractures treated nonoperatively. This can be treated with open-reduction internal fixation if no arthritis is present, with or without bone graft.
Malunion: Usually the result of inadequate closed or open treatment of displaced surgical neck or greater tuberosity fragments. When healed in a position of malalignment, bony impingement, poor motion, and weakness can result. This can be treated with an osteotomy, and internal fixation if no arthritis is present.
Avascular Necrosis: The humeral head receives its blood supply from the anterior and posterior humeral circumflex arteries. Direct injury to these vessels or fracture displacement that disrupts the intraosseous blood supply can result in avascular necrosis. This is most commonly seen after 4-part fractures. Clinical manifestations include insidious onset of shoulder pain months to years after the initial trauma. Radiographic examination typically reveals subarticular collapse of the head. This can be treated with prosthetic joint replacement (hemiarthroplasty or total shoulder replacement).
COMPREHENSION QUESTIONS
10.1 A proximal humerus fracture has the following morphology. There is 1.5-cm displacement at the surgical neck and fracture lines involving both the greater and lesser tuberosities, but without displacement. According to the Neer classification, what would this fracture be classified as?
A. One partB. Two partC. Three partD. Four partE. None of the above
10.2 Which combination of radiographs is sufficient to evaluate a proximal humerus fracture?
A. AP, internal rotation view, scapular YB. AP, internal rotation view, external rotation viewC. AP, scapular Y, axillary viewD. Internal rotation view, scapular Y, Stryker notch viewE. Axillary view, Velpeau view, scapular Y
10.3 An 80-year-old woman sustains a mechanical fall onto her right side. She is diagnosed with a minimally displaced right proximal humerus fracture (1 part). Which of the following is the most appropriate treatment?
A. Sling immobilization followed by early range of motionB. Open-reduction internal fixationC. Closed reduction and percutaneous pinningD. Intramedullary nailingE. Hemiarthroplasty
ANSWERS
10.1 B. Two-part fracture. Only the humeral head fragment is displaced (>1 cm), at the surgical neck. The tuberosity fragments are nondisplaced and thus not considered “parts.” This means that the fracture has a shaft part and a head part, making it a 2-part fracture.
10.2 C. AP, scapular Y, and axillary view. Anything less than these views is insufficient, and the patient should be sent back for appropriate radiographs.
10.3 A. Sling immobilization followed by early range of motion. This is a 1-part fracture in an elderly patient. This does not require operative intervention.
CLINICAL PEARLS
► Most proximal humerus fractures occur in older individuals as a result of low-energy trauma. ► Radiographic evaluation of the shoulder must include an AP, scapular Y, and axillary view, at a minimum. ► The most commonly used classification for proximal humerus fractures is the Neer classification. This is based on the number parts that are displaced (>1 cm or 45 degrees angulated). ► The majority of proximal humerus fractures are minimally displaced and can be treated nonoperatively with sling immobilization followed by early range-of-motion exercises. ► Displaced 2- and 3-part as well as valgus impacted 4-part proximal humerus fractures are best treated operatively with internal fixation (particularly in younger patients). ► Unreconstructable fractures or fractures at risk of developing avascular necrosis (four part fractures, head splitting fractures) should be treated with hemiarthroplasty. |
REFERENCES
Browner BD. Skeletal Trauma: Basic Science, Management, and Reconstruction . 4th ed. Philadelphia, PA: Saunders Elsevier; 2009.
Canale ST. Campbell’s Operative Orthopaedics . 11th ed. Philadelphia, PA: Mosby/Elsevier; 2008.
Court-Brown CM, McQueen MM. Nonunions of the proximal humerus: their prevalence and functional outcome. J Trauma . 2008;64(6):1517-1521.
Gerber C, Schneeberger A, Vinh TS. The arterial vascularization of the humeral head: An anatomical study. J Bone Joint Surg Am. 1990;72:1486-1494.
Hettrich CM, Boraiah S, Dyke JP, Neviaser A, Helfet DL, Lorich DG. Quantitative assessment of the vascularity of the proximal part of the humerus. J Bone Joint Surg Am. 2010;92(4):943-948.
Neer CS 2nd. Displaced proximal humeral fractures. I. Classification and evaluation. J Bone Joint Surg Am. 1970;52(6):1077-1089.
Stableforth PG. Four-part fractures of the neck of the humerus. J Bone Joint Surg Br. 1984;66:104-108.
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