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Proximal humerus fracture

A proximal fracture is a break in the upper end of the humerus bone, which forms the proximal portion of the upper arm and articulates with the to create the . These fractures account for 5% to 6% of all fractures and are the third most common type in older s, with an incidence rate of 60 to 105 per 100,000 person-years. They exhibit a bimodal distribution, affecting younger patients through high-energy mechanisms such as accidents or falls from height, while predominantly impacting individuals over 65 years old via low-energy falls, often exacerbated by or . Women are disproportionately affected, comprising about 75% of cases in those aged 60 and older, with hospitalization rates showing a 13% annual increase over recent decades. Epidemiology and Risk Factors
Proximal humerus fractures are classified as fragility fractures, underscoring their association with loss in the aging population. The female-to-male ratio is approximately 2:1, reflecting higher prevalence in postmenopausal women. In the elderly, over 70% of cases stem from simple falls, while in younger demographics, direct blows or high-impact predominate. Comorbidities like reduced increase susceptibility, and the injury often leads to significant morbidity, including shoulder stiffness and impaired function if not managed appropriately. Classification and Diagnosis
These fractures are typically classified using the Neer system, which divides the proximal into four anatomical parts—the humeral head (articular surface), greater tuberosity, lesser tuberosity, and shaft—and categorizes fractures as one- to four-part based on displacement greater than 1 cm or angulation exceeding 45 degrees. The AO/OTA classification further delineates them into extra-articular (type A), partial articular (type B), or complete articular (type C) patterns. relies on clinical presentation, including severe , swelling, bruising, limited motion, and possible , confirmed by imaging; advanced cases may require or MRI for assessing displacement or associated soft tissue injuries like rotator cuff tears. Treatment Approaches
Management varies by fracture displacement, patient age, and activity level, with 80% to 85% of minimally displaced fractures treated nonoperatively using sling immobilization for 3 to 6 weeks followed by to restore and strength. Displaced or complex fractures in active individuals may necessitate surgical intervention, including open reduction and with plates and screws, intramedullary nailing, or (such as hemiarthroplasty or reverse shoulder arthroplasty) for severe cases involving the humeral head. Recent trends as of 2025 show increasing utilization of reverse shoulder arthroplasty, amid ongoing debates on optimal management strategies for displaced fractures in the elderly. Outcomes depend on timely rehabilitation, with potential complications including , , or infection.

Background

Anatomy

The proximal humerus constitutes the upper portion of the , encompassing the humeral head, anatomical neck, greater and lesser tuberosities, and surgical neck. The humeral head is a smooth, hemispherical articular surface that articulates with the of the to form the , while the anatomical neck lies immediately distal to the head, separating it from the tuberosities. The greater tuberosity projects laterally and serves as an attachment site for muscles, and the lesser tuberosity is located anteromedially, with the intertubercular (bicipital) groove running between them for the long head of the ; the surgical neck, distal to the tuberosities, marks a common site of narrowing and vulnerability. The muscles—supraspinatus, infraspinatus, teres minor, and subscapularis—insert onto the tuberosities of the proximal , providing dynamic stability to the glenohumeral . The supraspinatus inserts superiorly on the greater tuberosity, the infraspinatus and teres minor insert posteriorly on the greater tuberosity, and the subscapularis inserts on the lesser tuberosity, collectively compressing the humeral head against the glenoid to facilitate smooth shoulder motion. These attachments enable a wide , including flexion, extension, , adduction, internal and external , while maintaining congruence during arm elevation and . The blood supply to the proximal primarily arises from the anterior humeral circumflex , whose ascending (arcuate) branch courses along the to supply the humeral head via a retrograde intraosseous system. This arcuate provides the majority of to the humeral head and tuberosities, entering through the anterior aspect and forming an anastomotic network critical for avoiding in injuries. Additional contributions come from the , but disruption of the arcuate branch poses significant risks to humeral head viability. In the glenohumeral joint, the proximal contributes to through its ball-and-socket configuration, where the humeral head's larger radius articulates with the shallower glenoid cavity, augmented by the and capsule for enhanced depth and containment. This allows for the shoulder's extensive mobility—up to 120 degrees of and 180 degrees of flexion—while relying on soft tissue structures like the for centered humeral head translation during motion.

Epidemiology

Proximal humerus fractures (PHFs) account for approximately 5-6% of all and represent the third most common fracture type in older s. The incidence exhibits a bimodal distribution, with peaks in young s due to high-energy such as accidents or , and in the elderly from low-energy falls, particularly in those over 60 years where rates can exceed 100 per 100,000 person-years. Overall population incidence rates vary by region but typically range from 60 to 150 per 100,000 person-years, rising sharply with age; for instance, women over 85 years experience rates up to 712 per 100,000 person-years. Demographic patterns show a higher in females, with a female-to-male ratio of approximately 2:1 overall and up to 4:1 in those over 50 years, largely attributable to osteoporosis-related fragility in postmenopausal women. Incidence increases with advancing age, affecting over 70% of cases in individuals beyond 60 years, and is projected to rise significantly due to aging populations; in the United States, the number of PHFs is expected to increase by about 50% to 275,000 annually by 2030. These trends underscore the growing burden in developed nations with longer life expectancies. Geographic variations reflect differences in population demographics and lifestyle factors, with higher age-adjusted incidences in regions with large elderly populations, such as and (often exceeding 100 per 100,000 person-years in the elderly), compared to lower overall rates in regions with younger demographics such as parts of (around 50-80 per 100,000 person-years). Registry data from the period (2020-2022) showed reduced incidence of PHF among older patients due to limited during lockdowns, as reported in . Post-pandemic trends as of 2025 indicate ongoing vulnerabilities in for elderly patients, though specific on rebounds remains limited. As of 2025, overall incidence rates in Western populations remain around 100-140 per 100,000 person-years, with projections estimating approximately 267,000 proximal humerus fractures by 2030, a nearly 70% increase from early levels. Some global estimates suggest a potential tripling by 2030 in aging societies. PHFs are a leading cause of shoulder disability in the elderly, often resulting in persistent , reduced , and functional impairment that contributes to loss of independence. They comprise about 10% of fractures in patients over 65 years and are among the most frequent upper extremity injuries in this group, exacerbating morbidity through complications like or in up to 20-30% of complex cases. This positions PHFs as a significant contributor to healthcare utilization and reduced in aging societies.

Etiology

Causes

Proximal humerus fractures primarily result from traumatic events that apply significant force to the shoulder region, though they can also arise from atraumatic pathological processes. In general, these fractures occur due to direct impacts or indirect forces transmitted through the arm, such as compressive loads, tension, torsion, or bending stresses on the proximal . Traumatic causes in younger patients typically involve high-energy mechanisms, including motor vehicle accidents or falls from height, which deliver direct blows to the or indirect axial loading through an outstretched . These events generate substantial varus or valgus stresses and rotational torques, often leading to displaced fractures in individuals with normal . In contrast, low-energy traumatic causes predominate in elderly patients, where simple ground-level falls onto an outstretched hand or the side of the body suffice to cause impaction or avulsion fractures of the humeral head or tuberosities. Such falls transmit axial compressive forces or bending moments to the proximal humerus, exploiting age-related bone fragility from osteoporosis. Atraumatic causes encompass pathological fractures that occur without significant external force, stemming from underlying conditions that weaken the bone structure. These include primary bone tumors such as or Ewing's sarcoma, benign lesions like enchondromas or unicameral bone cysts, metastatic cancers (e.g., from breast or lung), and rarely infections leading to . Severe can also precipitate such fractures with minimal or no trauma, highlighting the role of intrinsic bone compromise.

Risk Factors

Risk factors for proximal humerus fractures encompass non-modifiable and modifiable elements that heighten fragility and fall susceptibility, with opportunities for prevention through and environmental interventions. These factors are particularly relevant in older adults, where low-energy falls predominate as the injury mechanism. Non-modifiable risk factors include advanced age, with incidence peaking after 65 years due to progressive decline and impaired balance. sex confers elevated risk, primarily from postmenopausal loss accelerating and development. Genetic predispositions, such as polymorphisms in genes regulating density (e.g., those influencing or synthesis), also contribute to inherent low mass and fracture vulnerability. Modifiable risk factors center on bone health optimization. , defined by (DEXA) scan showing a T-score of -2.5 or lower at the or , markedly elevates risk by reducing bone strength, often leading to breaks from minimal like a fall from standing height. , common in limited sunlight exposure or , compromises calcium absorption and muscle function, thereby increasing both bone fragility and fall propensity. A sedentary lifestyle diminishes bone loading and neuromuscular coordination, further weakening skeletal integrity. Excessive alcohol consumption disrupts and balance, while tobacco use accelerates bone loss through impaired activity and vascular effects. Environmental factors play a key role, especially in fall prevention among the elderly. Inadequate home safety measures, such as loose rugs, cluttered floors, or absence of grab bars in bathrooms, substantially raise the likelihood of slips and trips indoors. Occupational hazards in high-risk professions like , involving working at heights, heavy lifting, or unstable surfaces, heighten exposure to traumatic falls or direct impacts. Comorbidities that impair mobility or balance are significant contributors. Neurological conditions, including with its characteristic tremors and rigidity, and history of leading to , compromise postural stability and elevate fall rates. Recent analyses indicate that —concurrent use of five or more medications—is associated with increased fall and fracture risk in older adults through side effects like or orthostasis, with some studies showing nearly 50% higher risk for fall injuries in cases of persistent .

Pathophysiology

Mechanism of Injury

Proximal humerus fractures often result from direct impact to the lateral aspect of the shoulder, where compressive forces applied to the greater tuberosity or surgical neck lead to avulsion of the tuberosity or fracture at the surgical neck. This mechanism typically occurs during a fall directly onto the shoulder, causing the humeral head to impact the scapula without significant axial loading of the arm. In such cases, the force vector is perpendicular to the humerus, resulting in undisplaced humeral head split fractures or valgus impaction of the articular margin. Indirect forces, such as those from a fall on an outstretched hand, transmit axial loads up the arm to the proximal , causing impaction of the humeral head against the glenoid or splitting of the . This common , known as the parachute reflex, positions the arm in approximately 90° abduction, 20° forward flexion, and 30° internal rotation, leading to shield-type fractures or displaced greater tuberosity fractures as energy is absorbed proximally. The resulting fracture patterns depend on the combination of axial compression, , and torsion, with muscle-tendon units influencing fragment displacement. Rotational and torsional mechanisms involve twisting injuries that generate forces across the proximal humerus, often avulsing the lesser tuberosity through contraction of the subscapularis . These occur in convulsive events like seizures or electric shocks, where violent, unbalanced muscle around the exceed bone strength, or in high-velocity scenarios such as or accidents involving rapid arm rotation. Torsion can produce spiral fractures propagating from the surgical neck distally. The energy threshold for varies by quality and , with low-energy impacts—such as falls from standing height—sufficient in osteoporotic common among the elderly, often leading to comminuted patterns in thinned cortices. In contrast, younger with denser typically require high-energy trauma, including falls from greater heights or vehicular collisions, to disrupt the proximal . Biomechanical studies indicate that forces in the range of several thousand newtons, depending on vector and , are needed to initiate surgical neck , though exact thresholds correlate strongly with cortical thinning ( 7.766).

Fracture Patterns

Proximal humerus fractures disrupt the bone at the metaphysis or articular surface, with metaphyseal involvement typically affecting the surgical neck and articular fractures extending into the humeral head, as seen in head-split patterns where the fracture line transverses the head obliquely. commonly manifests as varus angulation of the humeral head relative to the shaft, particularly in unstable configurations, leading to altered biomechanics and potential . Associated soft tissue pathology frequently includes tears, with an incidence ranging from 10% to 50% in patients with proximal humerus fractures, often involving the supraspinatus tendon. injury occurs in up to 19% of cases, typically due to traction or direct trauma during fracture displacement. Vascular compromise, particularly disruption of the arcuate artery branch of the anterior humeral circumflex, predisposes displaced fractures to of the humeral head, with rates of 20-30% reported in multi-part displaced patterns. The healing biology of proximal humerus fractures begins with hematoma formation at the fracture site, initiating an inflammatory cascade that recruits cytokines such as IL-6 for immune modulation and VEGF to stimulate and vascular ingrowth. In the , repair proceeds via , where bone forms directly from mesenchymal precursors, whereas the articular humeral head relies on , involving cartilage intermediate formation and subsequent replacement by bone. These processes are interdependent, with the inflammatory phase bridging soft development to hard remodeling over 6-12 weeks in stable fractures. Healing complications arise from the region's precarious blood supply, particularly to the humeral head, contributing to delayed in cases where bridging fails to form within 6 months. Unstable patterns increase mal risks, with varus collapse or tuberosity displacement leading to persistent and impaired in nonoperatively managed displaced . In contaminated , recent studies emphasize formation on implants or bone fragments as a key factor in chronic , complicating and necessitating revision in affected cases. These patterns underpin classification systems such as Neer, which categorize based on part displacement to guide and management.

Clinical Features

Signs and Symptoms

Patients with proximal humerus fractures typically present with severe, immediate in the that often radiates down the and is exacerbated by any movement or attempted shoulder motion. In undisplaced fractures, persistent night may occur due to ongoing swelling and , disrupting sleep. Functional limitations are prominent, including an inability to actively abduct or rotate the , with patients often holding the adducted against the to minimize discomfort. In displaced fractures involving the , pseudoparalysis may develop, characterized by severe restriction in active forward elevation (less than 90 degrees) despite preserved passive . Visible signs include localized swelling around the and ecchymosis over the deltoid region, which may extend to the chest, arm, or within 24-48 hours post-injury. can be evident in displaced cases; may also be palpable over the fracture site. Associated symptoms may include numbness or in the distribution of the , signaling potential neurovascular injury, with involvement being the most common and often transient. Vascular compromise may present as diminished or absent brachial , though rare (incidence approximately 5%). Symptoms can vary based on fracture patterns, with greater displacement leading to more pronounced and functional deficits.

Diagnosis

Physical Examination

The physical examination of a proximal humerus fracture is a critical initial step to assess the extent of , fracture stability, and associated complications, performed gently to avoid further . It systematically evaluates the and upper extremity, beginning with to identify visible signs of . Asymmetry in contour, such as shortening or prominence of the humeral head, may indicate , while swelling and are common due to formation. Bruising patterns, including ecchymosis around the that can extend to the chest, , and within 24-48 hours, suggest significant soft tissue involvement. also includes checking for open wounds indicative of open fractures and assessing for pulsatile or expanding masses that may signal vascular . Neurovascular status is evaluated concurrently, with of radial and ulnar pulses to confirm adequate and sensory testing over the C5-T1 dermatomes to detect involvement. Palpation follows inspection and focuses on localizing tenderness and instability while minimizing patient discomfort. The examiner palpates the proximal , particularly the surgical neck, greater tuberosity, and lesser tuberosity, where point tenderness is typically elicited due to the site. , a from bone fragments rubbing together, may be noted during gentle , signaling . To assess for open s, the skin is carefully inspected and palpated for breaches communicating with the . Signs of in the arm, such as tense swelling, disproportionate pain, or pain on passive finger extension, should be evaluated, as these can complicate proximal humerus injuries. is tested by gently rotating the humeral shaft while palpating the humeral head; unified motion indicates a stable , whereas independent movement or suggests instability requiring further intervention. Range of motion testing differentiates between active and passive movements to gauge integrity and fracture stability. Active abduction and external rotation are often severely limited by , while passive motion may reveal restrictions due to mechanical block from displaced fragments. Comparing passive to active range helps assess function; significant differences may indicate associated tears. The neurovascular examination is expanded here, with specific attention to the , the most commonly injured in these fractures, tested via sensation over the deltoid (regimental badge area) and strength against resistance. Distal motor and sensory functions, including wrist and finger extension for integrity, complete this assessment. Special tests are employed judiciously to identify associated without exacerbating the injury. Stability is further probed through gentle maneuvers, such as applying varus or valgus force to the without attempting reduction, to detect excessive laxity. These tests prioritize neurovascular preservation, with immediate cessation if pulses diminish or neurologic deficits worsen.

Imaging

Plain radiographs remain the initial and most common imaging modality for diagnosing proximal humerus fractures, with a sensitivity of approximately 95% for detecting the fracture. Standard views include a true anteroposterior () view of the glenohumeral joint, a scapular Y lateral view, and an axillary lateral view to assess fracture location, , and alignment. When the axillary view is painful or impossible due to patient discomfort, the Velpeau view serves as a reliable alternative, allowing imaging with the arm in a . These radiographs enable measurement of key parameters, such as greater than 1 cm or angulation exceeding 45 degrees between fracture fragments, which indicate significant instability. is recommended for preoperative planning in displaced or complex fractures, while MRI is selectively used for suspected injuries. For complex fractures where plain radiographs are inconclusive, computed tomography () offers detailed evaluation through multiplanar and three-dimensional reconstructions, particularly useful in cases involving head-split patterns or . CT enhances preoperative planning by improving assessment of fragment displacement and bone quality compared to plain radiographs alone. () is indicated when injuries are suspected, such as tears, which occur in nearly 40% of proximal humerus fractures in older patients; is useful for detecting these tears, though sensitivity can vary in the acute fracture setting. Ultrasound is an emerging adjunct in the emergency setting for dynamic assessment of fractures and associated injuries, including rotator cuff integrity and vascular flow via Doppler, though its utility is limited in obese patients due to acoustic shadowing. It may detect occult fractures or guide initial management in resource-limited environments. Radiation exposure must be minimized following the ALARA (as low as reasonably achievable) principle, as imaging choices balance diagnostic yield with risk. A single shoulder plain radiograph delivers approximately 0.01 mSv, equivalent to about one day of natural , while of the shoulder typically involves 5-10 mSv, comparable to 1-2 years of background exposure.

Classification

Proximal humerus fractures are classified using established systems to facilitate communication among clinicians, predict outcomes, and guide decisions. These systems primarily rely on radiographic features such as , fragmentation, and involvement of the articular surface, though advanced imaging like computed tomography can refine assessments. The Neer classification, introduced in 1970, categorizes fractures based on the number of displaced "parts" derived from the four anatomical segments of the proximal : the humeral head, , greater tuberosity, and lesser tuberosity. is defined as greater than 1 cm or 45 degrees of angulation. One-part fractures involve no displaced segments and are minimally displaced; two-part fractures feature of one segment, such as an isolated tuberosity or surgical neck fracture; three-part fractures include displacement of the surgical neck plus one tuberosity; and four-part fractures involve all segments, often with multifragmentary patterns or head , increasing complexity and risk. This system has demonstrated substantial interobserver reliability, with values ranging from 0.61 to 0.80 in experienced hands. The AO/OTA classification, developed by the Orthopaedic Trauma Association and Arbeitsgemeinschaft für Osteosynthesefragen, designates proximal humerus fractures as type 11 and divides them into three main categories based on location and articular involvement: type A (extra-articular, unifocal, such as metaphyseal simple fractures), type B (extra-articular bifocal, typically involving the surgical neck and one tuberosity), and type C (articular, with varying degrees of head-split or ). Each category has three subtypes (1-3) detailing displacement and fragmentation severity. This alphanumeric system is widely adopted in orthopedic literature for its comprehensive anatomic detail, appearing routinely in clinical studies and guidelines. Both systems have limitations, including variable interobserver agreement, particularly for complex , and limited incorporation of or vascular status. Recent validations from 2023 to 2025 highlight that the Neer system correlates better with prognostic factors like risk, while the / excels in surgical planning due to its focus on morphology; modified versions, such as those integrating Hertel criteria for head , address deficiencies to improve predictive accuracy. Clinically, the Neer classification aids in risk stratification, as four-part fractures are associated with a higher incidence of , reported at approximately 34% due to disrupted blood supply to the humeral head.

Treatment

Nonoperative Management

Nonoperative management is the preferred approach for stable proximal humerus fractures, particularly one- or two-part fractures that are minimally , defined as greater tuberosity displacement less than 5 mm and articular segment displacement less than 1 cm or angulation less than 45 degrees. This conservative strategy is especially suitable for elderly patients with comorbidities or low functional demands, where nonoperative treatment is applied in 65% to 85% of cases to minimize surgical risks. Immobilization typically involves a or collar-and-cuff for 2 to 4 weeks to promote initial stability and reduce , while avoiding prolonged restriction to prevent joint stiffness. Early initiation of pendulum exercises during this period helps maintain shoulder mobility without compromising healing. Pain control focuses on nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or acetaminophen for mild to moderate discomfort, supplemented by application and arm elevation to reduce swelling. Long-term opioid use is discouraged due to risks of and side effects, with approaches prioritizing non-narcotic options. Follow-up includes serial radiographs at 1, 3, and 6 weeks to assess alignment and progression. In undisplaced fractures, radiographic rates reach 98%, with functional outcomes typically yielding Constant-Murley scores of 68 to 70 or higher in elderly patients at 2 years post-injury.

Operative Management

Operative management is indicated for displaced or unstable proximal humerus fractures, particularly three- and four-part fractures according to the Neer classification, where exceeds 1 cm or angulation surpasses 45 degrees. Surgery is also recommended for young, active patients with significant , as well as open fractures classified under Gustilo-Anderson types I to IIIB, to restore and function. In contrast, minimally displaced fractures may be managed nonoperatively in select cases. Fixation techniques vary by fracture pattern. Percutaneous pinning is suitable for two-part fractures, providing minimally invasive stabilization with reduced soft tissue disruption. For metaphyseal involvement in three- or four-part fractures, locking plates such as the Proximal Internal Locking System (PHILOS) are preferred, achieving union rates of approximately 95% in clinical series. Tension band constructs, often using wires or heavy sutures, are employed for isolated or associated greater or lesser tuberosity fractures to counteract tensile forces across the rotator cuff insertions. Advanced options address more complex or comminuted patterns. Intramedullary nails are effective for surgical neck fractures, offering stable fixation with less periosteal stripping compared to plating. In elderly patients with head-split components or severe comminution, hemiarthroplasty or reverse shoulder arthroplasty is indicated, with 2025 meta-analyses indicating lower revision rates for reverse shoulder arthroplasty compared to hemiarthroplasty and open reduction internal fixation due to improved implant designs and patient selection. Surgical risks include infection rates of 2-5%, particularly in contaminated open fractures, and hardware in up to 10% of cases involving osteoporotic bone. Optimal timing is within 14 days of injury to minimize soft tissue swelling and complications while allowing adequate preoperative planning.

Rehabilitation

Rehabilitation following treatment for proximal humerus fracture focuses on a phased approach to restore shoulder function, minimize complications, and promote safe return to daily activities. Protocols are typically tailored based on whether the management was nonoperative or operative, with nonoperative cases often allowing earlier initiation of motion to prevent . The primary goals include , protection of fracture healing, and progressive restoration of (ROM) and strength, guided by radiographic evidence of union and patient tolerance. In Phase 1 (0-6 weeks post-injury or ), the emphasis is on with a worn continuously except during or gentle exercises, to protect against humeral head and allow initial fracture consolidation. Passive exercises, such as (Codman) swings, are introduced early—often within the first week for nonoperative cases—to maintain mobility and control through modalities like and analgesics. The key objectives are reduction, prevention of (a common complication occurring in up to 30% of cases if is prolonged), and initiation of elbow, , and hand to avoid secondary issues. Precautions include avoiding active motion or external beyond 40 degrees, with limited to 1-2 pounds on the affected arm. Phase 2 (6-12 weeks) transitions to active-assisted once radiographic healing is confirmed, discontinuing the sling as tolerated. Exercises include external rotation with a , wall walks for forward , and continued pendulums to achieve 90-140 degrees of flexion by the end of this period. Isometric strengthening of the and periscapular muscles begins around 8 weeks, focusing on deltoid and stabilizers without resistance to avoid stressing the site. Goals center on achieving painless active-assisted motion and normalizing , with supervised 2-3 times weekly to monitor progress and adjust for operative versus nonoperative differences—such as delayed active motion in surgical cases to protect . In Phase 3 (beyond 12 weeks), full active is pursued through resisted exercises using light bands or 1-5 pound weights, progressing to eccentric and proprioceptive for advanced . Criteria for to work or sports include at least 140 degrees of forward flexion, symmetric strength, and absence of pain during overhead activities, often achieved by 3-6 months with consistent adherence. Strengthening targets all upper extremity muscles, including the , with 8-12 repetitions in 2-3 sets, 3 times weekly. Evidence from recent protocols supports early within 1-2 weeks to reduce short-term stiffness, with one 2025 showing early active yielding a 13-point higher Constant-Murley score (88.7 vs. 75.3) at 24 months compared to conventional delayed approaches, alongside improved and pain scores. A 2024 confirms use for about 3 weeks and exercises starting day 1 as standard, with active-assisted at 3 weeks leading to better functional recovery without increased complications. These phased programs, adapted for type, emphasize multidisciplinary oversight to optimize outcomes.

Special Populations

Children

Proximal humerus fractures in children are relatively uncommon, comprising approximately 1-2% of all pediatric fractures, with an annual incidence of about 31.4 per 100,000 children. In neonates, these fractures may result from birth due to rotation or hyperextension of the upper extremity during delivery. These injuries predominantly affect the proximal physis or metaphysis, often presenting as Salter-Harris type I or II physeal fractures, while metaphyseal greenstick fractures are also frequent due to the bone's elasticity in this age group. The proximal humeral physis contributes roughly 80% of the 's longitudinal growth, conferring substantial remodeling potential—particularly in children younger than 10 years, where over 90% of fractures achieve satisfactory alignment without intervention. These fractures typically result from high-energy mechanisms, such as falls during activities (accounting for about 25% of cases) or accidents (around 33%), with direct blows to the also common. In children younger than 3 years, up to 54% of humerus fractures may be attributable to nonaccidental trauma, necessitating a high index of suspicion for in this demographic. Unlike adult fractures, which often stem from low-energy falls in osteoporotic bone, pediatric cases leverage the skeleton's greater and growth capacity. Management in children favors nonoperative approaches, with immobilization via , , or shoulder immobilizer achieving union rates exceeding 95% in most cases, given the bone's potential. Operative intervention, such as open and (ORIF), is reserved for rare instances involving greater than 50% displacement, significant angulation, or neurovascular compromise, particularly in adolescents with reduced remodeling ability. Outcomes are generally excellent, with near-complete remodeling and functional recovery in the majority of patients, though long-term monitoring is essential to detect growth arrest, which occurs in approximately 5% of physeal injuries. The 2025 guidelines underscore the importance of routine abuse screening in young children presenting with these fractures to facilitate early intervention and multidisciplinary evaluation.

Elderly Patients

In elderly patients, proximal humerus fractures typically result from low-energy mechanisms, such as falls from standing height, accounting for approximately 80% of cases due to underlying that predisposes to fragility fractures. These fractures often present as comminuted patterns because of poor bone quality, with a higher proportion of complex four-part injuries—up to 40% in this population—compared to younger individuals. Management strategies in older adults emphasize a higher threshold for nonoperative treatment, particularly in low-demand patients with minimally displaced fractures, where conservative approaches succeed in 65-85% of cases through and early . For more complex fractures, reverse shoulder arthroplasty is increasingly preferred over due to challenges with achieving stable union in osteoporotic bone, with reported union rates around 70% for fixation in elderly patients versus over 90% in younger cohorts. Elderly patients face unique challenges, including comorbidities such as (affecting 17% as a leading mortality factor) and (21%), which can delay and increase postoperative complications. Falls in this group also carry a risk of , exacerbating recovery in frail individuals with reduced physiological reserve. Recent advances include the use of cement-augmented locking plates for fractures in poor bone quality, with 2024 meta-analyses showing reduced implant-related complications and improved stability compared to standard fixation. Functional outcomes in these patients typically yield scores of 30-40 at one year post-treatment, reflecting moderate residual disability but acceptable recovery for daily activities.

Outcomes

Complications

Complications following proximal humerus fractures can significantly impact patient recovery and , encompassing early postoperative issues, late-onset structural failures, and systemic effects particularly in vulnerable populations. These adverse events vary by fracture severity, treatment modality, and patient factors, with surgical interventions generally carrying higher risks than nonoperative management. Early complications include , neurovascular , and joint stiffness. Surgical site infections occur in 0-8% of cases after open reduction and internal fixation (ORIF), with deep infections around 1.4-1.8%; rates are higher in open fractures due to contamination risks. Neurovascular injuries affect approximately 0.09-5% of patients overall, with the being the most commonly involved (incidence 6.2-67% across studies, though symptomatic cases are rarer at ~10% in displaced fractures); injuries are less frequent at about 1%. Shoulder stiffness, often manifesting as adhesive capsulitis or frozen shoulder, develops in up to 4-15% of cases, particularly with prolonged . Late complications primarily involve (AVN), or , pathology, and implant-related problems. AVN of the humeral head occurs in 6-17% after ORIF, rising to 21-40% (and up to 77% in some series) for four-part fractures due to disrupted blood supply. and rates range from 5-15% and 2-31%, respectively, with often leading to varus collapse (6.8%) or functional impairment. tears or emerge in complex fractures, exacerbated by tuberosity displacement. Implant complications, such as screw cutout or loosening, affect 8-13.8% of locking plate fixations, contributing to reoperation needs. The Neer can predict these risks, with four-part patterns associated with higher AVN and rates. Systemic complications are prominent in elderly patients and include delirium, thromboembolism, and opioid dependency. affects 5-20% of geriatric cases, linked to pain, hospitalization, and comorbidities. Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and (PE), occurs in 0.7% overall (DVT 0.14%, PE 0.59%) after surgery, necessitating prophylactic measures like anticoagulants in immobilized or operative patients. dependency post-fracture arises in up to 46% of cases at 3 months, with preoperative use increasing risk 2.4-fold and complex fractures (e.g., three- or four-part) adding 1.9-fold; recent data emphasize pain management to mitigate long-term reliance. Risk mitigation strategies focus on early to prevent stiffness and VTE, to reduce odds by up to 5.5-fold, and tailored surgical techniques like proper screw placement to avoid implant failures. Surgical cases exhibit 2.5-3.3 times higher overall complication rates than nonoperative approaches.

Prognosis

The prognosis for proximal humerus fractures varies based on fracture characteristics, patient demographics, and treatment modality, with many patients achieving satisfactory functional recovery but a notable subset experiencing persistent limitations in shoulder function and quality of life. Long-term outcomes are typically assessed using validated scoring systems such as the Constant-Murley Score (), which evaluates pain, , mobility, and strength, and the Disabilities of the Arm, , and Hand () questionnaire, which measures upper extremity disability. For nonoperative , mean CMS scores at 1 year post-injury range from 68 to 72 points out of 100 in elderly patients, indicating moderate functional restoration, while DASH scores reflect residual disability of approximately 18 to 25 points, suggesting mild to moderate ongoing impairment. Several patient and injury-related factors significantly influence . Advanced age, particularly in those over 65 years, is associated with lower rates of good or excellent outcomes, with fewer than 70% achieving satisfactory function due to comorbidities, reduced quality, and slower healing. Greater , such as in three- or four-part fractures classified by the Neer system, correlates with poorer results, including up to 50% risk of unsatisfactory outcomes characterized by limited and strength deficits. Timely surgical intervention, ideally within 2 weeks of injury, is associated with better patient-reported outcomes compared to delayed procedures, supporting guidelines such as those from the Swedish Shoulder Arthroplasty Registry. Return to daily activities is generally favorable, with about 80% of patients regaining in by 6 months post-fracture, though full shoulder abduction and external rotation may remain restricted. In younger, working-age individuals, return to employment typically occurs within 3 to 6 months, with over two-thirds resuming unrestricted duties by 3 months following operative fixation. Recent longitudinal studies from 2024 indicate that lasting beyond 1 year can occur, often linked to residual stiffness or involvement, but adherence to structured protocols improves pain resolution and overall quality-of-life scores. These findings underscore the importance of individualized follow-up to optimize long-term health.