Copeland surface replacement (CSRA) in cuff arthropathy – indications and results

Authors: O Levy

References: SECEC, Rome 2005

CUFF ARTHROPATHY:
A massive rotator cuff tear that allows the humeral head to be displaced upward, causing erosion of the anterior acromion and the acromioclavicular joint and collapse of the atrophic humeral head.  The incongruous head eventually erode deeply the glenoid and coracoid as well.

Copeland surface replacement arthroplasty (CRSA) of the shoulder was introduced for clinical use in 1986.  this prosthesis was specially designed for use in the less destroyed shoulder so that maximal bone stock is remained, minimal bone removed and cementless fixation obtained with a primary press fit and then a secondary biological fixation by bony in-growth into Hydroxyapatite coating.  The humeral shaft is not violated and therefore there is no stress riser effect at the midshaft of the humerus reducing the chance of humeral shaft fracture.  The prosthesis is centred on the anatomic head therefore allowing for infinite variability of offset, varus/valgus angulation and rotation.  Subsequent revision or arthrodesis, should it be necessary, be easier as the humeral head was not removed at the initial operation and bone stock maintained. 

The indications for the use of Copeland surface replacement arthroplasty (CRSA) are the same as for any other shoulder replacement (Primary osteoarthritis, Rheumatoid arthritis, Cuff arthropathy, Avascular necrosis, Instability arthropathy, Post-traumatic arthropathy, Developmental arthropathies) – all!! – the main indication for surgery is pain.  Shoulder replacement (and Surface replacement) is not indicated for pain free cuff tear with pseudoparalysis. 

AETIOLOGIES FOR CUFF DEFICIENT SHOULDER INCLUDE:
- RA
- Post traumatic
- Massive RCT

CRSA COMPARED TO REVERSE GEOMETRY PROSTHESIS:
- CRSA

• Good pain relief, moderate ROM (ADL), good rotations in waist level
• Less complex procedure – Quick and minimally invasive surgery
• All bone stock preserved – keeps options for future revision or arthrodesis
• At least as good as stemmed prosthesis

Reversed (Delta & like)

• More complex Surgery, high complication rate
• Good pain relief, good ROM – elevation
• Limited rotations – problem in ADL – self-Hygiene
• If fails – What to do next?! – as massive bone resected

Oversize Cup? – Impossible in CRSA

• But the aim is to re-establish normal head size (pre collapse!) with lateralisation of centre of rotation and tensioning of the Deltoid muscle
• To err on the larger size
• Use of impaction bone graft

CRSA should cover the articulating surface
In Cuff arthropathy – 15° upward to cover the articulating surface against the upper glenoid and acromion.

Osteoporosis

• Theoretically might be a problem – but practically was not found to be a problem!
• To overcome soft bone – Impaction bone grafting!

RESULTS:
Between 1993 to 2003, 24 shoulders with cuff arthropathy (5 Bilateral) were operated with Copeland surface replacement arthroplasty (CRSA).  18 females and 6 males with mean age of 75.7 years.  Preop Constant score of 8 points (12 points age/sex adjusted) improved to 48 points (72 points age/sex adjusted), with pain score improving from 0 to 12/15.
ROM improved for 49.6° preop to 84.6° at the last follow-up in Elevation (gain of 35°), 38.3° to 82.1° (44.8° gain) in abduction and 5.8° to 50.8° (45° gain) in external rotation. 
Kaplan Meier survival analysis showed survival of 0.875 at 11 years.
The Copeland Surface replacement arthroplasty (CRSA) in Cuff arthropathy shows reasonable results with good pain relief and adequate ADL activity in this elderly group of patients, avoiding complex and high complication rate surgery.
CSRA should be considered first choice in younger patients with good bone stock.