Internal Impingement
What is Internal Impingement?
Internal impingement of the shoulder is a pathologic condition characterized by excessive or repetitive contact of the greater tuberosity of the humeral head with the posterosuperior aspect of the glenoid when the arm is abducted and externally rotated. Internal impingement deals with more of the articular side of the rotator cuff, and specifically refers to the contact between the articular side of the supra/infraspinatus and the posterosuperior rim of the glenoid.
What Causes it?
The condition is mainly seen in athletes, where overhead activity is a major part of their sport, particularly throwing athletes. In US this is commonly seen in baseball pitchers, whilst in UK in my practice I see it particularly in weightlifters, avid gym goers, rugby payers, racquet sports player and overhead workers such as builders and plasters are particularly prone to developing this condition.
What are the symptoms?
The main symptom patients with internal impingement usually complain of is pain. This is usually made worse by over-head activity or throwing. The pain is a result of inflammation and irritation to the tendons which are being impinged. There may also be shoulder instability as a result of the damage done to the labrum. The damage done to the rotator cuff may cause a weakness in the movements of the shoulder, particularly abduction and external rotation, the movements discussed above as being crucial to throwing.
How is it diagnosed?
Internal impingement is usually diagnosed on clinical examination.
There is usually reduction in total range of rotation of shoulder especially of the internal rotation. This has to be examined with the patient lying on the back and compared to the other side. This also reproduces the symptoms.
Investigations:
X-Ray is used to look for any bony changes. MRI or MR Arthrogram is used to look for any damage to the rotator cuff or the labral cartilage (SLAP Tear).
Treatment:
- Conservative treatment comprising of rest, activity modification and non steroidal anti-inflammatory may be helpful in the early stages and when symptoms are mild
- Physiotherapy: A rehabilitation programme may be directed by a physical or occupational therapist may be helpful in stretching the joint and preventing the loss of movements. The success depends on the level of pain and expectations.
- Injections: An ultrasound or fluoroscopy guided injection in the AC joint provides a decrease in inflammation and reduces pain.Cortisone’s effects are often temporary, but it can give very effective relief in the short term. It also aids in confirming the diagnosis.
- Arthroscopic Technique
If the non-operative treatment fails, then the commonest form of surgical intervention is recommended. A fibre-optic scope and small, pencil-sized instruments are inserted through small incisions instead of a large incision. The arthroscope is connected to a television monitor and the surgeon can perform the repair under video control.
After surgery, the arm will be placed in a sling for a short period of time. This allows for early healing. As soon as comfort allows, the sling may be removed to begin exercise and use of the arm.
Non Operative Treatment
- Immobilization. A sling is recommended, keeping the arm immobilized for a few days till it becomes comfortable and the amount of time varies on the degree of displacement, discomfort, age of the patient, and other medical conditions.
- Pain control. Regular non-steroidal anti-inflammatory drugs, including ibuprofen, and/or other pain medications during the healing process.
- Range-of-motion exercises. Gentle range-of-motion exercises may begin as soon as possible and comfortable after the injury.
- Physical therapy. Physical therapy can start 2 to 3 weeks after the injury occurs.