Shoulder replacement has come a long way since it was first attempted in 1893! Shoulder replacement is now a predictable and reliable procedure with increasing evidence supporting its use. Modern shoulder replacement has evolved from a one piece monobloc hemiarthoplasty implant mainly used for fractures, to an anatomical shoulder replacement with a metal humeral head articulating on a polyethylene glenoid socket. The most recent variation of shoulder replacement now involves inverting the position of the components. The development of the Reverse Total Shoulder Replacement (RTSR) has allowed the expansion of the indications and increasing confidence in the outcomes of this procedure.
There are about 6500 shoulder replacements done each year in Australia and this number is increasing by around 10 % every year. Around 75% of shoulder replacements performed in this country are now reverse total shoulder replacements with this number increasing to 90% in patients over 65 years of age
The key difference that has allowed the expansion in indications is that a reverse replacement no longer requires a functional rotator cuff to keep the shoulder enlocated and stable. The reversal of the components and medialisation of the centre of rotation of the shoulder makes a reverse replacement inherently more stable and bypasses the need for a functional rotator cuff. The lever arm of the deltoid muscle is improved and with this restoration of movement and function.
meniscus tears is generally key-hole (arthroscopic) and may involve trimming or
removing part of the torn meniscus (partial meniscectomy) or repair of the
meniscus with various stitching techniques. Meniscus repair can be complex and
difficult surgery and has an overall success rate of between 75-85% but does
require careful protection after surgery and prolonged rehabilitation.
The reverse replacement has provided a reliable option for older patients with cuff deficient shoulders causing arthritis. It also has an increasing role for treatment of fractures and patients with bone loss of the humerus or glenoid. Reverse replacement also gives greater options for patients who require revision total shoulder replacement with most revisions now performed as reverse replacements.
The AOA joint registry now shows an overall lower revision rate for reverse replacements when compared with anatomical replacements but we need to interpret these results with caution. Most surgeons still believe the best functional results can be achieved with an anatomical replacement and this should still be the prefered option for young patients with arthritis and a functional rotator cuff.