DefinitionIntramuscular fibrous bands within the deltoid muscle that lead to contractures and stiffness of the deltoid and the shoulder joint.
- Seen in people of all ages, but it is reported primarily in children.
- Often associated with congenital/developmental defects.
- There is a genetic predisposition for the condition and other fibrotic conditions.
- It is very rare in USA but more common in Asia.
EtiologyThe etiology is unknown. Risk factors include intramuscular injections, trauma and other congenital factors.
PathogenesisThere might be a muscle abnormality initially which makes the patients susceptible to injury and development of fibrosis.
PathoanatomyShort fibrous bands replace the deltoid muscle. The contractures are most common, in order of frequency, in the middle, posterior and anterior part. More than one part may be affected simultaneously.
SymptomsDifficulty with the movement of the shoulder, affecting the activities of daily living. The patient complains of the inability to pull the arm fully down to the side of the body. Another symptom is pain near the shoulder and neck.
- Abduction contractures at the shoulder, with elevation and winging of the scapula (inferior border of the scapula rotates medially) when the arms are adducted.
- Dimpling of the skin, due to the fibrotic bands, may also be seen.
- Subluxation/dislocation of the humeral head may occur in severe cases (due to fibrosis involving anterior or posterior parts).
X-rayIs done to exclude glenohumeral and scapulothoracic pathology.
Computer Tomography (CT)Can reveal typical bony changes.
Magnetic Resonance Imaging (MRI)Can reveal typical bony changes.
OverviewThe treatment of deltoid fibrosis is surgical.
Nonoperative TreatmentConservative treatment with stretching or physical therapy are not helpful.
- Contracture > 25°
- Age > 5 years
- Progressively increasing contracture
- Painful contracture
Postoperative treatment: The arm is immobilized in an adducted position for about two weeks after the surgery. After that period the patient will start with physical therapy.
COMPLICATIONS AND PROGNOSIS
ComplicationsPostoperative complications: Keloid formation, hematoma or infection.
- The majority of patients have pain relief, a return of full range of motion and a resolution of scapular winging after surgery.
- There is a 6% recurrence rate of the condition.