A Hill-Sachs lesion is a dent or compression injury in the head of the humerus, the upper arm bone, that usually happens when the shoulder dislocates anteriorly. In simple terms, when the ball of the shoulder joint slips out of place, it can strike the edge of the socket and create a bony defect.[1][2] I often explain to patients that this lesion is not a separate disease by itself. It is usually part of the overall problem of shoulder instability.
In Bangladesh, many patients come after a first shoulder dislocation and ask whether the bone damage will heal on its own. Others have repeated dislocations and still do not understand why the shoulder keeps slipping. One important point I want patients to understand is that a Hill-Sachs lesion can affect shoulder stability, especially if it is large or combined with other injuries such as a labral tear or bone loss from the socket side.[1][2]
Not every Hill-Sachs lesion needs surgery. But not every one can be ignored either. The correct treatment depends on whether the shoulder remains stable, how often it dislocates, how large the defect is, and whether other injuries are present.
What exactly is a Hill-Sachs lesion?
The shoulder is a ball-and-socket joint. The ball is the humeral head, and the socket is the glenoid. During an anterior shoulder dislocation, the humeral head can impact against the edge of the glenoid, causing a compression defect in the posterolateral part of the humeral head. That defect is called a Hill-Sachs lesion.[1][2]
Why it matters
The problem is not only the dent itself. The concern is whether that defect makes the shoulder more likely to catch, slip, or dislocate again during certain movements. This is especially relevant in younger patients, active individuals, and people with recurrent instability.[2][3]
When does it happen?
A Hill-Sachs lesion most often happens after:
- an anterior shoulder dislocation
- sports-related trauma
- a fall
- road traffic injury
- a forceful twisting injury of the arm
In some patients, the lesion occurs after the first dislocation. In others, repeated dislocations can make the overall instability picture worse.[1][2]
What symptoms can it cause?
The lesion itself may not cause a unique symptom at the beginning. Many symptoms come from the dislocation and the unstable shoulder overall.
Common symptoms after the injury
Patients may report:
- severe pain at the time of dislocation
- difficulty moving the arm
- a visible deformity during dislocation
- fear that the shoulder will slip again
- clicking or catching
- weakness after the injury
- repeated episodes of instability
Later on, a patient may say the shoulder feels unreliable in certain positions, especially when the arm is lifted and rotated outward.[2][3]
Does every shoulder dislocation mean there is a Hill-Sachs lesion?
No, but it is common after anterior dislocation. Imaging helps determine whether the lesion is present and how significant it is.[1][2]
Why imaging matters
The size and position of the lesion help guide treatment decisions. A small defect may not change management much, while a larger engaging lesion can be important in surgical planning.[2][3]
Why is it linked to repeated dislocation?
I usually explain this simply: if the shoulder has both soft-tissue injury and bone-related injury, stability becomes more difficult. A Hill-Sachs lesion can contribute to the shoulder slipping again, especially if the socket side also has damage such as a Bankarts Tear.[2][3]
The “engaging” problem
Orthopedic literature describes that some Hill-Sachs lesions engage with the glenoid rim during certain movements, making instability more likely.[2][3] This is why the lesion must be considered in the full context of shoulder instability, not in isolation.
How is it diagnosed?
Diagnosis usually starts with the history of a dislocation and shoulder examination, then continues with imaging.
Clinical assessment
When I assess these patients, I focus on:
- whether it was a first or repeated dislocation
- how the injury happened
- whether the shoulder feels unstable now
- whether there is weakness or stiffness
- whether daily activities are affected
- whether the patient is young and active or more sedentary
Imaging tests
X-rays
X-rays often help confirm dislocation history and may show the bony defect.
CT scan
CT can be useful for better understanding bone loss and the exact size of the lesion, especially when surgery is being considered.[2]
