Shoulder Arthritis
Reviewed by
Dr Owen Mattern
BSc(hons), MBBS, PhD |
Unaccredited Orthopaedic Registrar
Basics
- Ball and socket synovial joint
- 4 basic characteristics for normal function
- Motion (most mobile joint in the body. Capsule lax until extremes of ROM)
- Stability (inherently unstable combated by: glenoid labrum, anatomically orientated humeral head: 130deg hea shaft angle 30 deg retroversion, extensive humeral articulation, anatomical glenoid 0-1 deg retroversion, net humeral joint reaction forces by all shoulder muscles working in synchronicity)
- Strength (functional deltoid and RC)
- Smoothness (smooth surfaces lubricated with synovial fluid)
- Motion (most mobile joint in the body. Capsule lax until extremes of ROM)
Glenohumeral Arthritis
- Causes
- Osteoarthritis
- posterior glenoid wear leading to relative retroversion
- posterior glenoid wear leading to relative retroversion
- Inflammatory arthropathies
- 91 % RA pts report shoulder pain
- Post traumatic
- Both from fracture and instability (1/10 recurrent instability will lead to arthritis within 10 years)
- Both from fracture and instability (1/10 recurrent instability will lead to arthritis within 10 years)
- Cuff tear arthropathy
- Others
- post stabilisation
- particularly anterior with over tightened anterior capsule leading to posterior directed joint forces.
- Osteonecrosis
- raumatic and nontraumatic.
- Infective
- Neuropathic
- post stabilisation
- Osteoarthritis