Humeral head fracture: description
The upper arm bone (humerus) has a relatively large head, three times larger than the glenoid cavity in which it lies. This allows the shoulder a wide range of motion: the shoulder joint is the most mobile joint in the human body. The shoulder joint is stabilized mainly by the surrounding tendons, muscles, ligaments and soft tissues.
Structure of the humerus
A thinner neck (collum chirurgicum) follows directly below the tuberculum minus. Here the bone is very soft and narrow. In the event of external force, this area can break particularly easily. The shaft of the upper arm bone (humeral shaft) adjoins the collum chirurgicum.
Humeral fractures
Upper arm fractures near the shoulder joint account for about five percent of all fractures. This makes the upper arm the third most common fracture site in the human body. In old age, this fracture occurs frequently. Women are affected two to three times more often than men. In adolescents, significant force is required for such a fracture to occur.
Humeral head fracture: classification
- Humeral head: tilting due to compression
- Tuberculum majus: by muscle traction displacement of the fragments backwards-upwards
- Tuberculum minus: by muscle traction displacement of the fragments to the front-center
- Shaft: by muscle traction displacement of the fragments to the front-center
A classification of humeral head fractures according to physician Neer is based on the number of fragments with or without displacement:
- Group I: 1 fragment, no or minimal displacement
- Group II: 2 fragments, displaced at the collum anatomicum
- Group IV: 2, 3 or 4 fragments, tearing off of the tuberculum majus, possibly tearing off of the tuberculum minus.
- Group V: 2, 3 or 4 fragments, avulsion of tuberculum minus, possibly avulsion of tuberculum majus
- Group VI: Luxation fractures
A fragment is displaced more than one centimeter or twisted more than 45 degrees.
An AO classification (Stans 2018) of proximal humerus fractures is based on the number of fragments:
- A: Extraarticular 2-fragment fracture.
- B: Extraarticular 3-fragment fracture
Humeral head fracture: Symptoms
If there is severe pain in the shoulder area after an accident, this may indicate a humeral head fracture. Another sign of such a fracture is the inability to move the arm or shoulder. The area is usually swollen and painful with pressure.
Humeral head fracture: causes and risk factors
In young people, a humeral head fracture is less common than in older people and is often the result of serious traffic or sports accidents (turf trauma). In babies, a humeral fracture can occur during birth.
Humeral head fracture: necrosis
The reason for humeral head necrosis is that the bone no longer receives an adequate blood supply. This happens when certain blood vessels are injured: the anterior humeral circumflex artery and its terminal branch, the arcuate artery, and the posterior humeral circumflex artery. Humeral head necrosis is one of the aseptic bone necroses, i.e., not caused by infection.
Humeral head fracture: examinations and diagnosis
Medical history and physical examination
Possible questions the physician may ask during the medical history interview include:
- Did you fall on your shoulder or outstretched arm?
- Can you describe exactly how the accident happened?
- Can you still move the shoulder or arm?
- Do you feel any pain?
- Were there any previous complaints of pain, restricted movement, or a previous dislocation in the shoulder or arm area?
A shoulder dislocation (shoulder luxation) shows similar symptoms to a humeral head fracture. Therefore, the doctor will examine you for any nerve and vascular injuries.
Apparative examinations
To confirm the suspected diagnosis of humeral head fracture, X-rays are usually taken from all sides of the shoulder. On the images, the doctor can also see whether fracture parts have shifted or whether other bony structures are broken.
If there are special questions, the doctor can order a magnetic resonance imaging (MRI). This can be used, for example, to detect or rule out soft tissue damage such as tendon injuries.
Angiography (vascular X-ray) can be used to localize the site of a possible vascular injury. Electromyography (EMG) can be used to determine whether the muscles and/or nerves are still intact.
Humeral head fracture: treatment
Humeral head fracture: Conservative therapy
In the case of an uncomplicated humeral fracture, surgery can be avoided in many cases. Provided the fracture fragments are not displaced against each other, the humerus is usually immobilized with a special bandage (Desault or Gilchrist bandage) for about a week. Some patients receive accompanying cold therapy (cryotherapy).
It is important to monitor the healing progress with X-ray controls. As a rule, a control follows after one day, ten days and six weeks. The bone is stable again after about six weeks if healing is adequate.
Humeral head fracture: surgical therapy
In general, there are two different surgical procedures depending on the location and type of injury: osteosynthesis and joint replacement (endoprosthesis). The surgeon also decides whether open or closed surgery is indicated, depending on the type of fracture.
However, if additional vessels or nerves have been injured, surgery is usually performed immediately to prevent permanent damage. Even in the case of a dislocation that can no longer be set, the doctor usually decides to operate immediately.
Osteosynthesis
If it is an unstable humeral head fracture with a severely displaced fracture as well as a dislocation fracture, surgery is also performed. The goal is to anatomically restore the humeral head so that follow-up treatment is not necessary.
Endoprosthesis
In younger patients, an attempt is always made to preserve the humeral head and to realign the fracture components anatomically.
Humeral head fracture: course of the disease and prognosis
It is recommended that the shoulder joint not be completely immobilized for more than two to three weeks, otherwise a so-called “frozen shoulder” may develop – a painful stiffening of the shoulder.
Other possible complications of humeral head fracture include:
- Humeral head necrosis (especially in older patients)
- Impingement: painful entrapment of soft tissues in the joint space (between the acromion and the humeral head) in the case of a tuberosity majus fracture
- Labrum lesion (injury to the joint lip)
- Rotator cuff rupture (tear of the muscle group in the shoulder area)
- Vascular and nerve damage (such as to the axillary nerves or axillary artery) in severe humeral head fracture
