A humeral head fracture, more precisely called a proximal humerus fracture, is a break at the top of the upper arm bone where it forms the ball of the shoulder joint. These fractures are among the most common in older adults, with an overall incidence around 82 per 100,000 person-years and a strong skew toward women over 60 whose bones have thinned from osteoporosis. The good news is that the majority of these fractures are minimally displaced, and most people recover well without surgery. But when the bone fragments are significantly shifted, or when the blood supply to the humeral head is disrupted, the injury becomes substantially more complex, and the treatment decisions become genuinely difficult.
Who Gets These Fractures and How They Happen
The typical patient is a woman in her late 60s or 70s who falls onto an outstretched hand or directly onto the shoulder. One large trauma-center series found a two-to-one ratio of women to men and a mean age of 70.1PubMed. Epidemiology of proximal humerus fractures managed in a trauma center A separate epidemiological study put the incidence in women at about 114 per 100,000 person-years versus 47 in men, with the rate climbing steeply in older age groups.2PubMed. Epidemiology of proximal humerus fractures Osteoporosis is the main driver: the proximal humerus is largely cancellous (spongy) bone, and as mineral density drops, even a low-energy fall can fracture it.
In younger people, proximal humerus fractures usually require higher-energy trauma, like a motorcycle crash or a fall from height. There is also an unusual mechanism worth knowing about: epileptic seizures. During a convulsion the shoulder is forced into a position that can lever the humeral head against the rim of the socket, and continued muscle contraction can produce complex fractures or fracture-dislocations. Forceful restraint of a person’s limbs during a seizure can contribute to the injury as well.3PubMed Central. Bilateral posterior fracture-dislocation of the shoulders following epileptic seizures: a case report and review of the literature
Why Blood Supply to the Humeral Head Matters So Much
The humeral head sits somewhat precariously at the end of its blood supply. The main feeding vessel is a branch of the anterior circumflex artery, sometimes called the arcuate artery, which runs up to enter the bone near the greater tuberosity. A secondary network of smaller vessels arrives from the posterior circumflex artery, entering the bone along the medial edge of the head near the cartilage-bone junction.4PubMed. The arteries of the humeral head and their relevance in fracture treatment This blood supply also shows a lot of anatomical variation from person to person.5PubMed Central. The humeral head: A review of the blood supply and possible link to osteonecrosis following rotator cuff repair
When a fracture disrupts the arcuate artery, the medial vessels become the last lifeline keeping the humeral head alive. If those are disrupted too, the bone loses its blood supply entirely and begins to die, a process called osteonecrosis (sometimes called avascular necrosis). This is the single most feared complication of a proximal humerus fracture, because a dead humeral head eventually collapses and destroys the joint. Understanding this vascular anatomy is central to both surgical planning and predicting which fractures are at highest risk.
How These Fractures Are Diagnosed and Classified
Diagnosis starts with standard X-rays, typically a set of views from different angles. For fractures that look complex on plain films, CT scans give a much clearer picture of how many fragments there are and how far they have shifted. Research comparing the reliability of different imaging methods found that CT scans produced substantially better agreement among surgeons classifying the fracture than X-rays alone.6PubMed Central. 3D-Printed Models versus CT Scan and X-Rays Imaging in the Diagnostic Evaluation of Proximal Humerus Fractures
The most widely used classification system, developed by Charles Neer in the 1970s, divides the proximal humerus into four parts: the humeral head itself, the greater tuberosity, the lesser tuberosity, and the shaft. A fracture is classified by how many of those parts are significantly displaced. The trouble is that surgeons frequently disagree about how to classify a given fracture under this system. A survey of 138 orthopedic shoulder surgeons found only fair agreement when classifying the same set of fracture images.7PubMed Central. The reliability of the Neer classification for proximal humerus fractures: a survey of orthopedic shoulder surgeons This poor reliability is a persistent problem in the field. It means that two surgeons looking at the same CT scan may describe the fracture differently, which can lead to different treatment recommendations. Patients seeking a second opinion should not be surprised if the classification label changes.
Conservative Treatment and When It Works
Most proximal humerus fractures are treated without surgery. A sling or shoulder immobilizer holds the arm in place during the initial healing phase, followed by a gradual rehabilitation program. For fractures where the fragments have not shifted much, conservative management leads to good outcomes in roughly 80 to 90 percent of patients.8PubMed Central. Conservative Treatment of Proximal Humerus Fractures: When, How, and What to Expect
That said, “good outcomes” hides considerable variation. A study tracking adults treated without surgery found that outcomes at one year varied widely, and a substantial portion of patients reported poor function. For most minimally displaced fractures, the biggest factor in how someone ended up feeling a year later was not the fracture itself but preexisting psychosocial factors like mood, expectations, and overall health. In the minority with more severe injuries, fracture-related factors such as degree of displacement, nonunion, and tuberosity displacement accounted for a measurable portion of the poorer results.9Journal of Bone and Joint Surgery. Functional Outcome After Nonoperative Treatment of a Proximal Humeral Fracture in Adults
The Surgery Versus No-Surgery Debate
One of the most important findings in proximal humerus fracture care came from the PROFHER trial, a large randomized study comparing surgical treatment with conservative management for displaced fractures involving the surgical neck. Over two years of follow-up, the trial found no significant difference in patient-reported outcomes between the two groups.10JAMA. Surgical vs Nonsurgical Treatment of Adults With Displaced Fractures of the Proximal Humerus: The PROFHER Randomized Clinical Trial The full trial report showed that the surgery group scored only 0.75 points higher on a 48-point shoulder outcome scale, a difference that was neither statistically nor clinically meaningful. Complication rates, further surgery rates, and mortality were all similar between the two groups.11PubMed Central. The ProFHER (PROximal Fracture of the Humerus: Evaluation by Randomisation) trial
This trial pushed back against the rising trend of operating on these fractures and is one of the reasons many orthopedic surgeons have become more conservative in their treatment recommendations. It does not mean surgery is never appropriate, but it does mean the bar for choosing surgery over non-operative care should be high, especially for two-part surgical neck fractures in older patients.
When Surgery Is Chosen
For fractures that are severely displaced, involve multiple fragments, or include a dislocation, surgery remains standard. The most common approach is open reduction and internal fixation using locking plates, essentially a metal plate screwed into the bone fragments to hold them in position while they heal. This technique has been refined over the years, and when done well, using anatomic reduction and a careful screw strategy, implant failure rates can be reduced to less than 10 percent. Adding acrylic cement augmentation in patients with thin bone may push failure rates even lower, to around 1 percent.12PubMed Central. Plate Fixation of Proximal Humerus Fractures: How to Get It Right and Future Directions for Improvement However, overall complication rates with locking plates have been reported as high as 40 percent, with reoperation rates reaching 25 percent, particularly in elderly patients.13PubMed Central. Plate Fixation of Proximal Humerus Fractures: How to Get It Right and Future Directions for Improvement
Locking plates generally offer stronger fixation than older plate designs. Biomechanical testing in cadavers has shown that locking plates withstand greater loads before failure compared with conventional plates.14PubMed. Biomechanical comparison of a unique locking plate versus a standard plate for internal fixation of proximal humerus fractures in a cadaveric model Intramedullary nails, inserted through the top of the humeral head and passed down the bone’s central canal, offer another option. Biomechanical work has shown that certain nail designs may be stronger still for unstable fracture patterns.15Journal of Trauma and Acute Care Surgery. Locked-Plate Fixation and Intramedullary Nailing for Proximal Humerus Fractures: A Biomechanical Evaluation
Bone Quality and Screw Cut-Out Risk
In older patients the biggest surgical worry is often the screws backing out through the soft bone of the humeral head, a complication called screw cut-out. One useful predictor is the deltoid tuberosity index, a measurement taken from X-rays that estimates how thick the bone cortex is in the upper arm. Patients with a low index (1.44 or below) had a significantly higher rate of screw cut-out: 12 percent compared with 2 percent. Between the ages of 65 and 80, the contrast was even starker at 17 percent versus zero. All patients over 80 were identified as high risk regardless of the index.16Obere Extremität. Predictive value of the deltoid tuberosity index for assessing the risk of screw cut-out This kind of preoperative screening helps surgeons decide whether to augment their fixation with cement or opt for a different procedure altogether.
Shoulder Replacement for Severe Fractures
When the fracture is too shattered for plate fixation, or when the humeral head has lost its blood supply, the head itself is replaced with a prosthesis. Two types are used: hemiarthroplasty (replacing only the ball) and reverse shoulder arthroplasty, which flips the mechanical design so the ball component sits on the socket side and the cup sits on the humeral side. This reverse design relies on the deltoid muscle rather than the rotator cuff to power the shoulder, which is a major advantage in older patients whose cuff tendons may already be worn or are disrupted by the fracture.
Multiple studies now show that reverse shoulder arthroplasty produces better long-term function than hemiarthroplasty for acute fractures in elderly patients. One registry-based study found that while the two procedures performed similarly at 6 months, the reverse shoulder group had significantly better scores at 5 years.17PubMed. Functional outcomes of reverse shoulder arthroplasty compared with hemiarthroplasty for acute proximal humeral fractures A randomized trial reported that patients with a reverse arthroplasty achieved significantly higher shoulder function scores and greater forward elevation and abduction than hemiarthroplasty patients.18PubMed. Reverse shoulder arthroplasty versus hemiarthroplasty for acute proximal humeral fractures A separate comparative study found forward elevation of 139 degrees in the reverse group versus 100 degrees with hemiarthroplasty, along with higher satisfaction rates of 91 percent versus 61 percent.19Journal of Bone and Joint Surgery. Comparison of Hemiarthroplasty and Reverse Shoulder Arthroplasty for the Treatment of Proximal Humeral Fractures in Elderly Patients In practice, reverse arthroplasty has become the preferred replacement option for most elderly patients with severely displaced or comminuted proximal humerus fractures.
Osteonecrosis of the Humeral Head
As noted above regarding blood supply, the humeral head can die after a fracture. A meta-analysis identified several risk factors for osteonecrosis after internal fixation: fracture complexity, the quality of the surgical reduction, the surgical approach used, and patient age all played a role.20PubMed. Risk factors for osteonecrosis of the humeral head after internal fixation of proximal humeral fractures: a systematic review and meta-analysis One detailed study found osteonecrosis in about 4 percent of patients after locking plate fixation, with most cases appearing in the first year. Among high-risk fractures, the rate climbed to 32 percent. But the same study offered a striking finding: when surgeons achieved a near-perfect reduction (less than 2 mm of remaining displacement), osteonecrosis was completely avoided even in the highest-risk group. Medial hinge displacement, meaning disruption of the bony connection on the inner side of the fracture, was present in every case that developed osteonecrosis.21PubMed Central. Protective and Risk Factors for Humerus Head Necrosis After Proximal Humerus Fracture Treated with Internal Locking Plate The takeaway is that surgical technique and fracture pattern matter enormously, and that a well-executed fixation can mitigate even a grim-looking risk profile.
Nerve and Soft Tissue Injuries
The axillary nerve wraps closely around the surgical neck of the humerus on its way to supply the deltoid muscle, which makes it vulnerable in these fractures. Intraoperative nerve monitoring during fracture repair has shown that the axillary nerve is the most frequently affected, involved in 46 percent of nerve injuries identified during surgery. Mixed patterns involving more than one nerve (brachial plexopathy) accounted for about 23 percent of cases, as did isolated radial nerve involvement.22PubMed Central. Nerve Monitoring During Proximal Humeral Fracture Fixation: What Have We Learned? More complex fracture patterns carry a higher risk of axillary nerve injury with muscle denervation.23Revista Española de CirugÃa Ortopédica y TraumatologÃa. Electromyographic axillary nerve injury in fractures of the proximal humerus
Rotator cuff tears are another associated concern, especially with fractures that involve the greater tuberosity (the bony bump where the cuff tendons attach). The severity of rotator cuff damage tends to increase with more complex fracture patterns and with greater displacement of the tuberosity fragment.24Clinical Orthopaedics and Related Research. Defining the Relationship Between Rotator Cuff Injury and Proximal Humerus Fractures These soft tissue injuries contribute to the stiffness and weakness that can persist long after the bone itself has healed.
Infection After Surgical Fixation
Post-operative infection following open reduction and internal fixation of proximal humerus fractures occurs in roughly 4 percent of patients. Most infections are caused by common skin bacteria, but one organism worth flagging is Cutibacterium acnes (formerly Propionibacterium acnes), a slow-growing bacterium that lives in the skin’s oil glands and is especially abundant around the shoulder. It is more commonly discussed as a complication of total shoulder replacement, but it has been identified after plate fixation as well. In one large series of 452 proximal humerus fractures, 18 patients developed acute deep infections, and one of those cultures grew C. acnes.25Journal of Orthopaedic Case Reports. Propionibacterium acnes Infection of the Shoulder After a Manipulation Under Anesthesia for Stiffness Status Post Open Reduction and Internal Fixation Proximal Humerus The challenge with C. acnes is that it grows slowly in culture, so samples need to be held in the lab for an extended period or it will be missed.
Rehabilitation and Early Movement
One of the most common questions patients have after a proximal humerus fracture is when they can start moving the shoulder. The instinct of both doctors and patients is often to immobilize the arm for several weeks, but multiple systematic reviews have examined whether starting gentle movement earlier, typically within the first week, leads to better results. The answer is nuanced: early mobilization appears to produce a small short-term functional advantage at around three months after injury, but the benefit fades over time. Importantly, moving the shoulder early does not increase the risk of the fracture shifting or cause more complications.26PubMed Central. Early versus delayed mobilisation for non-surgically treated proximal humerus fractures: a systematic review and meta-analysis of randomised trials
One meta-analysis found a statistically better combined function score favoring early mobilization at 3 months, with no difference in secondary fracture displacement or total complications between the early and delayed groups.27PubMed Central. Early versus delayed mobilisation for non-surgically treated proximal humerus fractures: a systematic review and meta-analysis of randomised trials An earlier review similarly found a small improvement in shoulder function scores with early mobilization, though it noted the improvement did not cross the threshold typically considered clinically meaningful, and it found no clear benefit for range of motion or pain.28PubMed Central. The Benefits and Harms of Early Mobilization and Supervised Exercise Therapy after Non-surgically Treated Proximal Humerus or Distal Radius fracture A broader systematic review of upper limb fracture rehabilitation echoed these findings, reporting improvements in pain and shoulder function within the first three months, with complication rates similar between groups.29International Journal of Research and Review. Impact of Early Mobilization Versus Immobilization After Upper Limb Fractures: A Systematic Review of Functional Recovery
The practical conclusion for patients: if your surgeon says you can start gentle pendulum exercises or passive motion within the first week, you are safe to do so and may recover your daily function a bit faster in the early months. But if circumstances or comfort lead to a few weeks of immobilization first, the long-term outcome is likely similar.
Nonunion and What Happens When Healing Stalls
Nonunion, where the fracture simply fails to heal, is uncommon after proximal humerus fractures but can be a difficult problem when it occurs. For younger patients with adequate bone quality, the usual strategy involves repeat fixation combined with bone grafting to stimulate healing. In elderly patients, especially those whose humeral head is no longer viable or whose rotator cuff is already compromised, reverse shoulder arthroplasty has emerged as the preferred solution.30Journal of Clinical Orthopaedics and Trauma. Neglected proximal humerus fracture nonunion: A narrative review Nonunion is more likely when fracture fragments are poorly aligned or when fixation is inadequate, which circles back to the importance of the initial treatment decision and surgical technique.
Proximal Humerus Fractures in Children
Children’s bones behave very differently from adult bones in this area. The growth plate near the top of the humerus is responsible for up to 80 percent of the bone’s total length growth, and this active growth gives children an extraordinary capacity to remodel a misaligned fracture over time.31PubMed. Evaluation and management of pediatric proximal humerus fractures As a result, proximal humerus fractures in young children can tolerate much greater angulation than the same fracture in an adult and still heal into a functionally normal shape. Most are treated with nothing more than a sling.32PubMed Central. Management of Pediatric Proximal Humerus Fractures
Older adolescents have less remodeling potential as their growth plates start to close, and they are more likely to need surgical fixation for significantly displaced fractures. Even in those cases, minimally invasive techniques like percutaneous pinning are often sufficient because the bone quality is excellent and the healing environment is forgiving.33Journal of the Pediatric Orthopaedic Society of North America. Percutaneous Fixation of Pediatric Proximal Humerus Fractures The contrast with the elderly population could not be starker: where an 80-year-old with a four-part fracture may need a shoulder replacement and months of rehabilitation, a 7-year-old with a similarly displaced fracture can often be placed in a sling, sent home, and expected to remodel the deformity completely within a year or two.