Clinical Benefits of the Sirius Canine Elbow System

Factors influencing implant failure are multifactorial, and are commonly related to:

• weakening of bone stock due to excessive bone resection and stress shielding
• implant loosening due to poor fixation and differential movement between the radius and ulna at the implant surface
• inadequate instrumentation
• difficult surgical approach

The Sirius benefits from advances gained over the past 40 years in human joint replacement, and has been developed by a team of highly experienced medical engineers and veterinary surgeons. The Sirius incorporates the following design features, which help to avoid the common problems historically associated with implant failure:

• bone conserving design requiring minimal bone resection: the Sirius simply resurfaces the ulnar surface, and preserves the majority of the distal humerus except for the mid-section of the trochlea. This design reduces the risk of bone resorption and weakening due to stress shielding.

• preservation of pronation and supination: earlier systems have required the inhibition of radial motion (for example, by use of locking screws and / or distal ostectomy). The Sirius tray is fixed to the ulna only, allowing free movement of the radius.

Sirius 3 canine elbow - post-op radiograph
Courtesy of Rob Pettitt, University of Liverpool

• primary and secondary fixation: the humeral stem is cemented and the box-cut distal end provides additional rotational and translational stability. The ulnar component benefits from initial multiple point screw and peg fixation and has a state of the art trabecular metal coating to ensure excellent long-term osseointegration.

• fully instrumented system and non-handed implant design: the Sirius system is fully instrumented, and has been developed in association with leading veterinary orthopaedic surgeons, to ensure optimal ergonomics and a straightforward surgical approach.