5. Rotator Cuff - Components
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
Which is the 5th component?
6. Rotator Cuff: Prime Functions
Prime INITIATOR of Abduction
ROTATION of the Humerus (90% of external rotation
strength)
STABILISER of the joint (Muscular balance)
COMPRESSOR of the Humeral head into the glenoid
fossa
DELTOID ---- FORCE of Abduction (55%)
7. Biomechanics:
ARM ELEVATION
STABILITY: Rotator Cuff & Long head of Biceps
Shoulder Girdle Complex muscles
FORCE & ENDURANCE: Deltoid
Rotator Cuff
BALANCE BETWEEN DELTOID FORCE & ARM WEIGHT
9. Rotator Cuff Tear - Minor
Elevation normal – ENDURANCE
shorter
Elevation by external rotation of the
shoulder – biceps becomes the head
depressor for the deltoid to act
10. Rotator Cuff Tears - Massive
Force Imbalance –
Instability
Superior subluxation of
the humeral head
Deltoid Retraction
Non-functional joint
12. Vascular Anatomy
Critical Zone – Supraspinatus
Codman, Lindblom, Uhthoff and co-workers
Adequate Vascularity
Moseley & Goldie. JBJS45B:780;1963
Swiontkowski et al. Laser Doppler Studies. St
Louis:Mosley Year book,1990:208
Rathman & Mcnab JBJS:52B:540;1970 – Poor filling
in adducted position
13. ROTATOR CUFF TEAR – WHY?
Aging is the single most important
contributing factor
Uhthoff HK, Sarkar K In Matsen FA et al (eds). The
Shoulder:AAOS:1993,269-278
14. ROTATOR CUFF TEAR – WHY?
LOADING ENVIRONMENT
Compressive Load between the
humeral head and the coracoacromial
arch
Ziegler et alJBJS:1996
Shearing Load to the deep surface
of the tendon by the glenoid rim
Matsen FA et al Practical Evaluation and
Management of the shoulder;WB Saunders:1994
40. REHABILITATION
Rest: 3 days (Pain relief)
Assessed by Upper Limb Therapist
Passive assisted exercises
Active assisted exercises after 2-3 weeks
Use arm for daily activities
Home Exercise Programme
49. RESULTS
Valenti PH, D. Boutens, C. Nerot et al
Long Term Results >5 years
Jan 91 – Dec 94
10 centres in Europe
Results of 39 presented & then Published in
“Shoulder Arthroplasty”