Principles of Reverse Shoulder Arthroplasty

Reversing the position of ball & socket of the shoulder joint(a ball & socket type of joint) when doing total joint replacement is Reverse shoulder Arthroplasty.
A conventional shoulder arthroplasty mimics the normal anatomy of the shoulder: a  “cup-prosthesis” fitted into the glenoid, and a “head-prosthesis” is attached to the top of humerus. In a reverse  shoulder replacement, the socket and ball(head) are switched. The metal ball is fixed to the glenoid and the plastic cup is fixed to the upper end of the humerus.


  1.  Cuff-tear arthropathy
  2. Massive rotator cuff tear with pseudoparalysis
  3. Severe  inflammatory  arthritis  with  a  massive  cuff  tear
  4. Failed  shoulder  arthroplasty:-
    ->Absence of tuberosities (failed hemiarthroplasty for fracture/nonunion)
    ->Absence of cuff (failed hemiarthroplasty for cuff-tear arthropathy)
  5. Proximal  humeral  fracture
  6. Proximal  humeral  nonunion
  7. Reimplantation  for  deep  periprosthetic  infection
  8. Reconstruction  after  tumor  removal
  • Contraindications:- 1. loss or inactivity of deltoid, 2. Excessive glenoid bone loss-no secure implantation of glenoid component, 3. Younger patients, 4. Surgeon Inexperience- a relative contraindication.
  • Biomechanism:- ~Reverse prosthesis works by changing the direction  of  pull of the deltoid.
    ~With standard prosthesis, humeral head subluxate superiorly due deltoid contraction in the absence of rotator cuff
    ~Reverse prosthesis corrects the subluxation by placing the centre of rotation of arm laterally & re-estabilishing a fulcrum around which the deltoid-pull can restore forward elevation.