New Instruments - 2005
COPELAND SURFACE REPLACEMENT ARTHROPLASTY - NEW INSTRUMENTS
Mr O Levy, Consultant Orthopaedic Surgeon, Royal Berkshire Hospital, UK
Presented at: International Shoulder Symposium - Leysin, Switzerland - 4-5 March 2005
Accuracy of bone preparation is important in joint replacement in general and in the Copeland Surface Replacement Arthroplasty as well. Although the current instrumentation is simple and quite accurate, question has been raised, mainly by our American colleagues, whether this can be improved. Especially in view of much wider option of sizes that was introduced mainly due to marketing requests. The new instrumentation retained its simplicity of use and friendliness. All the new instrumentation is now cannulated, for improvement of bone preparation accuracy. The order of bone preparation steps has changed slightly. After decision on the size of the prosthesis to be used using the jig. Introducing the guide wire and finding the centre of the humeral head with the wire, the head is then shaped according to the size decided using a cannulated shaper- reamer over this guide wire. There is a mechanism to stop the shaper - reamer from cutting down into the humeral head beyond the subchrondral bone. This safety feature helped in preserving the subchrondral bone, which is important structure for the fixation of the prosthesis. After the re-shaping of the humeral head, the central drill hole is prepared using the cannulated spade cutter and therefore there is better precision of the central hole size. In the new set there are 8 sizes of humeral head that will be numbered from 1 - 8. All besides the small and extra small prosthesis have the same central peg size as with the old system and therefore are interchangeable intra-operatively.