THR: Total Hip Replacement

The main design objective of the KYON Zurich Cementless THR, a proprietary system of implants, instruments and a surgical technique for canine total hip replacement, was to provide for an immediate and indefinitely stable anchorage of the prosthetic components. Total hip replacement techniques fall into two categories: Cemented and Cementless. Cemented THR provides fine short term, but less satisfactory long term outcomes. Aseptic loosening, the most common reason for long term failure of THR, is responsible for 75% of revisions in human patients. Conventional press-fit cementless THR’s have taken about 50% of the market, but the revision rates in all categories of human patients remain higher than with cemented THR.[1] The femoral and acetabular components of the Zurich Cementless THR reflect different, both novel, approaches to addressing the most common complications of canine total hip replacement.

In 1999, after six years of clinical experience, Prof. Pierre M. Montavon, Head of Small Animal Surgery at the School of Veterinary Medicine, University of Zurich, and Slobodan Tepic, Dr. Sci., Dipl.Ing., of the AO Research Institute, Davos, Switzerland, with the participation and advice of Dr. Aldo Vezzoni, DVM, Dipl. ECVS, Cremona, Italy, initiated an international, multi-center clinical study, to collect well-documented, broad-based clinical performance data on the Zurich Cementless Total Hip Replacement. Data contributed by fourteen surgeons from eight countries on over 750 cases is in the final stages of preparation for publication. Collection of the surgical reports and clinical follow-up were coordinated by Prof. Randy Boudrieau, DVM, Dipl. ACVS, Prof. of Surgery, Cummings School of Veterinary Medicine, Tufts University, Massachusetts, USA.


By the end of 2009, the Zurich Cementless THR had been used in over 9,000 dogs by more than 150 surgeons in Europe, the United States, Australia, and Japan. KYON holds an exclusive, worldwide patent license in the veterinary field for the anchorage of the THR femoral component from SCYON Orthopaedics AG.

BIOLOGICAL BENEFITS:

• Immediate and permanent proprietary locking-screw fixation
• Near-physiolological loading of the proximal femur – absence of stress shielding
• Full range of impingement free motion
• Minimal disruption of methaphysial cancellous bone
• Rapid bone ingrowth into a highly compliant acetabular cup
• Absence of wear-particle induced lysis

TECHNICAL FEATURES:

• Titanium and titanium alloy for supreme biocompatibility and reduced risk of infection
• Titanium plasma porous coating for micro-interlock
• Proprietary, hydraulically open, compliant, double shell metal backing for the cup
• Amorphous Diamond Like Coating (ADLC) on the Head-Necks, harder, smoother, and more lubricious than conventional coatings, insuring superb articulation
• Proprietary, wear-reducing geometry for the poly inlay