The deltoid tuberosity is a roughened V-shaped area on the lateral surface of the humeral shaft at about its midpoint, where the deltoid muscle inserts. It is palpable as a slight elevation on the lateral arm and serves as a landmark for the humeral midshaft. The radial nerve runs in the radial (spiral) groove on the posterior surface of the shaft just behind and below it.
| Articulations |
|
|---|---|
| Landmarks |
|
| Ossification | Formed on the humeral shaft by the primary centre, which appears at about the eighth fetal week; it has no secondary centre. |
The deltoid tuberosity helps predict deformity in humeral shaft fractures: below the deltoid insertion, the proximal fragment is pulled into abduction by the deltoid, while between the pectoralis major and deltoid insertions the proximal fragment is pulled into adduction. The radial nerve lies against the bone in the spiral groove behind the shaft and pierces the lateral intermuscular septum in the distal third, so it is at risk in midshaft and distal shaft fractures. Antegrade humeral nails enter near the greater tuberosity and retrograde nails just above the olecranon fossa. Insertional tendinopathy at the tuberosity is an uncommon cause of lateral arm pain.
Follow the outer side of the upper arm down to about its midpoint, where the bulk of deltoid narrows into a V. Ask the person to lift the arm sideways against light resistance to make the V stand out; the rough bony area at its tip is the deltoid tuberosity.
Midshaft and distal humeral shaft fractures can injure the radial nerve in or near the spiral groove, causing wrist drop; the spiral distal third (Holstein-Lewis) fracture is the classic pattern, and most palsies recover with observation.
Overuse irritation at the deltoid insertion causes pain over the lateral mid-arm, sometimes with calcific deposits.
This website uses cookies to enhance your experience. Some are essential for site functionality, while others help us analyze and improve your usage experience. Please review your options and make your choice.
If you are under 16 years old, please ensure that you have received consent from your parent or guardian for any non-essential cookies.
Your privacy is important to us. You can adjust your cookie settings at any time. For more information about how we use data, please read our privacy policy. You may change your preferences at any time by clicking on the settings button below.
Note that if you choose to disable some types of cookies, it may impact your experience of the site and the services we are able to offer.
Some required resources have been blocked, which can affect third-party services and may cause the site to not function properly.
This website uses cookies to enhance your browsing experience and ensure the site functions properly. By continuing to use this site, you acknowledge and accept our use of cookies.
