A Hill-Sachs Lesion is an injury to the rounded top of the arm bone also known as the Humerus. The shoulder is a ball and socket joint held in position by ligaments cartilage and tendons. The head of the Humerus sits within the socket to make the glenohumeral joint (the shoulder). An injury can cause this head of the Humerus to pop out of the socket it lays within, causing damage to part of the surrounding structures.
The shoulder joint typically dislocates in 3 main directions, downwards, backwards and forwards. The direction you dislocate/subluxate may determine the injury sustained. You can only get a Hill-Sachs lesion when there is a forward dislocation.
The damage occurs when the humeral head come out of the socket and collides with the edge of it. Due to the pain of the dislocation you may not initially know you have this injury. Secondary damage can also be associated with this type of injury.
The most common symptoms may include:
- Swelling or burning
- Visible deformity of the shoulder (bulge at the front)
- Difficultly moving the joint
- Muscle spasms
- Intense pain local to the shoulder
Causes and risk factors
The shoulder joint is a naturally flexible and unstable joint. The humeral head that sits in the socket its bigger than the socket that holds it. To keep this stable during exercise,s the ligaments and tendons combine to create the stability at the joint.
Common causes of dislocation
- Falls – ladder, downstairs (usually on and extended arm)
- Sports – collisions, falls and twisting movements
- Trauma – car/bike accidents
There are a number of different approaches to treatment for a dislocated shoulder. Firstly, depending on whether open surgery or arthroscopic surgery will be performed. If the dislocation involves bony damage to the Humerus bone or surrounding areas your doctor will consider further treatment.
Hill-Sachs lesion treatment is depending on the size of damage in the area, its placement and the mobility that you do or don’t have at the shoulder. If the lesion is less that 20% it is likely your doctor will try a conservative approach that doesn’t requires surgery. This will consist of strengthening exercises in a rehabilitation program to stabilise the joint.
However, if the lesion is between 20-40% of the humeral head the decision will be made based around whether the shoulder will be in a unstable state if not surgically treated.
Bone Augmentation – Grafting of bone over the damaged site
Remplissage– This process is surgically filling the damaged area with new tissue
Disimpaction – this involves a bone graft under the lesion to lift up the humeral head to its natural position
Resurfacing – this is where they will replace the whole of the humeral head. This is done on those who have recurrent injuries. The procedure is called a hemiarthroplasty.