Shoulder Impingement Syndromes
- primary impingement
- secondary impingement
- subcoracoid impingement
- posterior-superior glenoid impingement
a."internal glenoid impingement"
Primary Impingement
Etiologies of primary impingement:
- subacromial spurring
- subacromial fibrosis
- acromioclavicular (AC) joint spurring
- type II or III acromion
- os acromiale
Type I: < 25 years of age, reversible, swelling, tendonitis, no tears, conservative treatment.
Type II: 25-40 years of age, permanent scarring, tendonitis, no tears, subacromial decompression (SAD).
Type III: > 40 years of age, small RTC tear, SAD with debridement/repair.
Type IV: > 40 years of age, large RTC tear, SAD with repair.
Acromial Morphology
Type I Acromion: flat, minimal impingement.
Type II Acromion: curved, higher rate of impingement.
Type III Acromion: beaked, highest rate of impingement, may be degenerative or congenital.
Characteristics of Primary Impingement
- patients > 50 years of age
- consequence of aging
- mechanical compromise of the subacromial space
- degenerative joint diseases of the AC joint
- subacromial spurring
- cuff atrophy
- cuff or scapular weakness (poor posture)
Terminology
- Neer referred to primary impingement as "outlet" impingement.
- Dr. James Andrews calls it primary or external/subacromial impingement.
a. The superior or bursal side of the cuff is involved.Symptoms
- pain with overhead activities
- pain when sleeping on the affected shoulder
- anterior or anterolateral pain
Characteristics of Secondary Impingement
- Patients are under 50 years of age.
- Pain is anterior or anterolateral in location.
- It is usually associated with an overhead activity.
- Rarely night pain, unless chronic.
- Rursal side on the RTC is affected.
- Attenuation of the static anterior stabilizers leads to fatigue of the dynamic anterior stabilizers and subsequent anterior subluxation.
- Impingement is secondary to functional and/or static instability.
Internal Glenoid Impingement Characteristics
- posterior-superior impingement
- involvement of articular surface of the rotator cuff
- primarily seen in athletes using extensive overhead activities
- extension, abduction and external rotation
- impingement of the under side surface of the rotator cuff against the post-superior glenoid2
Initial Presentation
1. 65-year-old female with anterior shoulder pain when brushing her hair
a. primary impingement2. 18-year-old baseball pitcher with anterior shoulder pain
a. secondary impingement
3. History
4. Exacerbating activities: reaching overhead, behind back, throwing, etc.
5. How long have the symptoms been present?
6. Is there a history of past trauma (micro or macro)?
7. Any neurological complaints?
a. Weakness is a neurological complaint when presenting without pain.
Symptom Patterns
- Pain exacerbated by overhead activities and or symptomatic at night is classic for primary impingement. (Patient cannot lie on the shoulder.)
- Secondary and internal impingement may present in this manner; however, pain is more predictably associated with overhead throwing and is less symptomatic at night.
- Pain associated w/internal impingement usually is localized to the posterior aspect of the shoulder.
- Neurological symptoms usually are associated with instability and the "dead-arm syndrome."
a. Patients complain of heaviness, but lack true neurological deficit.
b. The "dead arm" results from the humeral head tractioning the brachial plexus during episodes of subluxation.3
References
- Neer, JBJS (A), 1972.
- Jobe, 1995; Arroyo, 1997; Buchberger, 2000
- Rowe JBJS (A), 1981.
Dale Buchberger, DC, DACBSP, ART
Associate Professor New York Chiropractic College
Seneca Falls, New York