The new head and neck prosthesis will have an Amorphous Diamond Like Coating (ADLC) that gives a smoother, harder, and more durable surface than the titanium nitride (TiN) coating used previously. The improved smoothness will lead to less wear on the polyethylene cup, due to its significantly lower coefficient of friction. The ADLC is a harder surface than TiN and will better resist scratching. It is biocompatible, inert, and highly corrosion resistant.

KYON is implementing this change as part of our continuing product improvement process. As our inventory of TiN coated heads is used, we will begin introducing the new ADLC coated heads. You will notice a change in the color, as the new heads are shiny and black due to the carbon, which makes them “diamond like” rather than the gold color of the TiN. The base material for the head and neck prosthesis is the same titanium alloy that we have always used.

This new coating technology is more expensive for us, but we believe that the increased hardness and better wear are worth it. The price increase to you will be $20.00 per head, which only partially offsets the increased production costs. The new heads will have new product numbers and our order forms will be revised as the change is completed and the TiN inventory exhausted. Until then, we will substitute the new heads on your orders as they become available.

Please note: we will not exchange existing TiN heads for new ADLC heads. Continue to use your existing inventory and order as needed. We will phase in the new heads beginning soon. Thank you again for your trust in KYON. Please feel free to contact us if you have additional questions or concerns.

Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, 200 Westboro Road, North Grafton, MA 01536, USA. randy.boudrieau@tufts.edu

OBJECTIVE: To review the proposed biomechanical basis of the tibial plateau leveling osteotomy (TPLO) and tibial tuberosity advancement (TTA) and recommendations for these techniques. STUDY DESIGN: Literature review. METHODS: Literature search through Ovid Medline Plus, Pub Med, CAB Abstracts, and conference proceedings abstracts (August 1983 to March 2008). RESULTS: TPLO and TTA stabilize the cranial cruciate ligament (CrCL) deficient stifle joint neutralizing tibiofemoral shear forces by altering the geometry of the proximal aspect of the tibia. Stability is attained by placing the joint in a functionally greater flexion angle so that the patellar tendon angle (PTA) remains < or =90 degrees. Both procedures target slightly differing endpoints, the significance of which is unknown. Many of the biomechanical variables investigated appear to favor the TTA; however, TPLO appears to have more clinical versatility. The clinical ramifications of these differences remain to be determined but the reported results for both procedures are comparable. Only the early results of these techniques have been reported, which is reflected in the relatively high number of complications associated with the early learning curve for both procedures. CONCLUSIONS: There are many similarities between TPLO and TTA although it remains to be fully elucidated if either procedure is superior and under what conditions. CLINICAL RELEVANCE: TPLO and TTA are effective at returning dogs with a CrCL-deficient stifle joint to good limb function. Surgeon discretion and case selection drive selection of TPLO or TTA based mostly on anecdotal evidence and personal experience.

PMID: 19152613 [PubMed - indexed for MEDLINE]

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Inauen R, Koch D, Bass M, Haessig M.

Koch & Bass Referral Practice for Small Animal Surgery, Basadingerstrasse 26, 8253 Diessenhofen, Switzerland. info@kochbass.ch

The influence of the tibial tuberosity conformation on cranial cruciate ligament (CrCl) rupture was evaluated and the size of the tibial tuberosity of healthy dogs (group H) was compared with dogs with CrCl rupture (group R) and dogs treated by tibial tuberosity advancement (TTA) (group T). The medio-lateral radiographs of 219 stifle joints were evaluated. Relative tibial tuberosity width (rTTW), proximal tibial tuberosity angle (PTTA), tibial plateau angle (TPA), tibial width (TW) and tibial plateau length (TPL) were measured on each radiograph. Body weight (BW) was measured and relative body weight (rBW) was calculated. The data from group H was compared with that of group R and group T. Group H had significantly larger rTTW, lower BW, lower rBW and smaller PTTA than group R. A comparison of groups H and T showed that dogs from group H were significantly younger, had a lower BW, a lower rBW, a greater PTTA and a smaller rTTW. In each of the comparisons, the TPA and the TW/TPL were not significantly different. The conformation of the canine tibial tuberosity has a significant influence on CrCl rupture. We hypothesized that the smaller the tibial tuberosity width, the larger the cranial tibial thrust, which results in more rapid CrCL degeneration, thus leading to rupture in a younger population of dogs. The rTTW could be a helpful measurement for breeding selection. Only dogs with a rTTW of more than 0.90 should be used for breeding.

PMID: 19151865 [PubMed - indexed for MEDLINE]

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Kim SE, Pozzi A, Banks SA, Conrad BP, Lewis DD

Departments of Small Animal Clinical Sciences, Mechanical and Aerospace Engineering, and Orthopedics and Rehabilitation, University of Florida, Gainesville, FL 32610, USA.

Objective- To evaluate the effects of tibial tuberosity advancement (TTA) on femorotibial contact mechanics and 3-dimensional kinematics in cranial cruciate ligament (CrCL)-deficient stifles of dogs. Study Design- In vitro biomechanical study. Animals- Unpaired pelvic limbs from 8 dogs, weighing 28-35 kg. Methods- Digital pressure sensors placed subjacent to the menisci were used to measure femorotibial contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135 degrees . Three-dimensional static poses of the stifle were obtained using a Microscribe digitizing arm. Each specimen was tested under normal, CrCL-deficient, and TTA-treated conditions. Repeated measures analysis of variance with a Tukey post hoc test (P<.05) was used for statistical comparison. Results- Significant disturbances to all measured contact mechanic parameters were evident after CrCL transection, which corresponded to marked cranial tibial subluxation and internal tibial rotation in the CrCL-deficient stifle. No significant differences in any contact mechanic and kinematic parameters were detected between normal and TTA-treated stifles. Conclusion- TTA eliminates craniocaudal stifle instability during simulated weight-bearing and concurrently restores femorotibial contact mechanics to normal. Clinical Relevance- TTA may mitigate the progression of stifle osteoarthritis in dogs afflicted with CrCL insufficiency by eliminating cranial tibial thrust while preserving the normal orientation of the proximal tibial articulating surface.

PMID: 19152615 [PubMed - indexed for MEDLINE]

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Inauen R, Koch D, Bass M.

Koch&Bass Referal Practice for Small Animal Surgery, Basadingerstrasse 26, 8253 Diessenhofen, Switzerland. rinauen@kochbass.ch

This report describes the successful use of the novel fixed-angle locking plating system ALPS (advanced locking plate system) in the case of dorsal tarsometatarsal instability in a cat. Partial arthrodesis of the tarsometatarsal joint was performed with a two hole ALPS 5 and two 2.4 mm selftapping locking screws through a small dorsal approach. Five days after the surgery the cat was walking without lameness. Radiographs made after six weeks showed uneventful healing. ALPS offers an alternative to existing plating systems when selecting an implant for the stabilisation of dorsal tarsometatarsal instabilities in cats.

PMID: 19290401 [PubMed - indexed for MEDLINE]

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Kipfer NM, Tepic S, Damur DM, Guerrero T, Hässig M, Montavon PM.

Clinic for Small Animal Surgery, Vetsuisse Faculty University of Zurich, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland. nkipfer@vetclinics.unizh.ch

OBJECTIVES: This in vitro study compares the femorotibial shear in canine stifles with intact and transected cranial cruciate ligaments (CrCL), before and after tibial tuberosity advancement (TTA) by measuring the distance between origin and insertion of the cruciate ligaments. METHODS: Radiodense markers were inserted into bones at the attachment sites of the cruciate ligaments in sixteen cadaveric stifles of adult dogs. Each stifle was then mounted in a testing apparatus. The distances between the markers were measured on mediolateral radiographs, performed on each stifle under three different situations: intact, after CrCL transection, and after performing a TTA. Stifles were loaded to create a constant tibiofemoral reaction force by maintaining the load parallel to the patellar ligament. Radiographs were taken in a preloaded and loaded state in the intact stifle and only in a loaded state after CrCL transection, and after performing a TTA. RESULTS: Loading the stifle joints after transection of the CrCL resulted in a mean lengthening of the CrCL marker distance of 22.4%. Loading the transected CrCL stifles after performing a TTA resulted in a mean shortening of the CrCL marker distance by 3.0% compared to the loaded intact condition. CLINICAL SIGNIFICANCE: This study demonstrates that, in loaded stifles with transected CrCLs, TTA causes a caudal shift in the cranial shear force, counteracting cranial subluxation of the tibia.

PMID: 19011700 [PubMed - indexed for MEDLINE]

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