A Hill-Sachs lesion, or Hill-Sachs impaction fracture, is an injury to the back portion of the rounded top of your upper arm bone (humerus). This injury occurs when you dislocate your shoulder. It’s named for the two American radiologists who first described the injury in 1940: Harold Hill and Maurice Sachs. Your shoulder is a ball-and-socket joint held in place with muscles, ligaments, cartilage, and tendons. The humerus bone sits in the socket, the cup-shaped labrum in your shoulder. An injury can pop the ball part of the joint out of the socket, causing pain and damaging parts of the joint.
A Hill-Sachs lesion or fracture occurs when the humerus bone pops out of the socket, scraping the head of the bone against the edge of the socket. You won’t be able to tell right away if you have a Hill-Sachs lesion. But you’ll feel the pain of your shoulder dislocation.
Also, more than one part of your shoulder may be damaged in an injury. A dislocated shoulder requires emergency care.
The symptoms of a dislocated shoulder are:
Your shoulder joint is very flexible. It can move in many directions and has many parts that can be injured.
The top of the humerus bone is called the humeral head. It’s larger than the socket that holds it. To keep it stable, tendons, muscle, and ligaments hold it in place.
Common causes for a dislocated shoulder include:
A 2010 study Trusted Source of 8,940 people with shoulder dislocations found that 58.8 percent of dislocations resulted from a fall. Of these cases, 47.7 percent occurred at home. And 34.5 percent occurred while playing sports or participating in some other type of recreation. Overall, 48.3 percent of all the dislocations occurred in sports or recreations.
Specific activity risks include:
A dislocated shoulder has a greater risk of recurrence after the first injury. However, data are limited for recurrence of dislocations for people with Hill-Sachs lesions. One meta-analysis cited two studies that showed if you have a Hill-Sachs lesion, you’re 1.55 times more likely to have a recurrence.
The outlook for recovery from a dislocated shoulder and a Hill-Sachs lesion is generally good. But a recurrence of a dislocation is common, especially in younger people.
In the long-term, about one-thirdTrusted Source of people who have surgery for a dislocated shoulder will develop shoulder arthritis. Talk to your doctor about a treatment and rehabilitation plan that will limit your risk of further complications.
