A humerus fracture is classified into three main types based on location: proximal (shoulder), mid-shaft (middle), or distal (elbow), and the specific type determines the best treatment approach.
Our upper arm is made of a single, thick, long humerus bone. Due to some mishap, if we break our arm, it’s actually a fractured humerus. Fracture can happen at the upper end of the humerus, the middle part or at the lower end of the bone.
Depending on the site of fracture, this could be classified into three different types. In this article, we will discuss all three different fracture humerus classification, their subtype and their potential causes.
Humerus Fracture Classification: A Simple Guide to Proximal, Mid-Shaft, and Distal Types
Depending on the nature and force of impact, the fracture can occur in four different sites. Depending on the fracture site, we can classify humerus fractures into three subheadings: the Proximal humerus fracture, Mid-shaft fracture and the Distal humerus fracture.
Let me share a true incident to make it clearer. There was a middle-aged male patient who suffered such a fracture, and he described his story as something like this.
“One fine morning, I was on a regular morning walk. I was enjoying my walk when suddenly I stumbled upon a rock by the side of the road and fell down. I outstretched my hand to fall on my hand only to find that my hand was in great pain. My doctor told me that I have broken my arm bone and it needs to be fixed by immobilising it using a sling or POP cast.
When we fall, we have a tendency to fall with hands outstretched. Outstretching of the hand is an involuntary reflex action that protects us from injuring our head and body. But sometimes it results in the injury of the hand and may cause fractures arm, forearm and hand.
The most common cause fracture is falling on the outstretched hand. Falling into an outstretched hand is actually a preventive reflex to prevent us from hurting. It can be while waking, while running, or simply when you fall from the bike.
1. Proximal Humerus Fracture: Injury to the Shoulder End
In a proximal humerus fracture, the fracture occurs on the upper end around the head and neck of the humerus bone. The most common site of fracture is the fracture at the neck of the humerus and the Fracture Greater Tuberosity.
The fracture could be displaced or undisplaced, depending on the impact of the injury.
The Proximal humerus fracture is further classified into four segments based on the number of displaced segments or parts. This popular classification was proposed by Neer1. A newer AO/OTA system was introduced in 2018 to try to simplify the coding process, but studies comparing the two still find the original Neer classification shows better agreement between different observers4.
Understanding the Neer Classification System
| Type | Description | |
| 1 | One-Part Fractures | No fragments meet the criteria for displacement; a fracture with no fragments considered displaced is defined as a one-part fracture regardless of the actual number of fracture lines or their location. |
| 2 | Two-Part Fractures | One segment is displaced, which may be the greater tuberosity, lesser tuberosity, or articular segment at the level of the anatomic neck or surgical neck. |
| 3 | Three-Part Fractures | With a three-part fracture, one tuberosity is displaced and the surgical neck fracture is displaced. The remaining tuberosity is attached, which produces a rotational deformity. |
| 4 | Four-Part Fractures | All four segments (both tuberosities, the articular surface, and the shaft) meet criteria for displacement. The articular segment typically is laterally displaced and out of contact with the glenoid. This is a severe injury and carries a high risk of avascular necrosis. |
2. Mid-Shaft Humerus Fracture: Breaking the Middle of the Arm
As the name suggests, fracture mid-shaft of humerus is a fracture at the middle portion of the shaft of the humerus bone. This fracture is also commonly seen in adult people of any age. It is of three types, and again, the type depends on the nature and type of fracture force. Broadly, it is categorised under three types.
- Spiral fracture: When a rotational or twisting force assaults the arm, the resulting fracture takes in a spiral pattern. This is why it is named the spiral fracture.
- Oblique or transverse fracture: When force is angular in nature, it leads to a fracture that runs obliquely in the shaft of the humerus.
- Comminuted fracture: The fractured part gets fragmented into several pieces. This may result from a direct blow or direct assault, or attack on the arm bone.
Beyond these descriptive patterns, humeral shaft fractures are also formally classified using the AO/OTA system, which sorts them into three types by fracture morphology: Type A (a simple fracture line), Type B (a separate wedge fragment), and Type C (a segmental fracture)2.
3. Distal Humerus Fracture: Injury at the Elbow End
It is the fracture at the lower end of the humerus bone. Two patterns are especially common here: the intercondylar fracture, which splits between the two condyles, and the supracondylar fracture, which occurs just above the elbow joint. The intercondylar pattern is also frequently seen in younger, active patients, and both usually result from a direct fall onto the tip of the elbow.
The fracture can be a two-part or a comminuted fracture. The treatment depends on whether the fracture is displaced or undisplaced. A fracture on the lower end of the humerus around the elbow can lead to an increase or decrease in carrying angle of elbow.
Distal humerus fractures also have their own formal classification: the AO/OTA system splits them into extra-articular, partial-articular (involving one condyle), and complete-articular (involving both condyles) fractures, and is currently the most widely used system for this region.
Even so, a 2024 comparison study found only fair agreement between different surgeons using AO/OTA to classify distal humerus fractures, which is why some surgeons now use newer, more consistent classification systems alongside it when planning treatment3.
Conclusion: Diagnosis and next steps for a humerus fracture
Getting the classification right matters because treatment and rehab timelines differ significantly between fracture types — a one-part proximal fracture is managed very differently from a comminuted mid-shaft break or a displaced distal fracture near the elbow.
For a broader look at how different fracture patterns are diagnosed and managed, see our guide on bone fracture types, diagnosis, and management. And if your fracture is near the elbow, our Elbow Fracture Rehabilitation Exercises PDF walks through a structured, phase-wise home recovery program once your doctor or physiotherapist clears you to begin.
FAQ on Humerus fracture
The author is a physiotherapist who has been practising for the last 17 years. He holds a Bachelor's in Physiotherapy (BPT) from SVNIRTAR (Swami Vivekananda National Institute of Rehabilitation and Research), one of the prestigious physiotherapy schools in India.
Whatever he learns dealing with his patient, he shares it with the world through blogs and e-books. He also owns a YouTube channel, "Sunit Physiotherapist" with over 8 lakh active subscribers. Here, he shares everything he gets to learn serving the patient.
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