DIAG IM3 - Page 136

15Internal 3 Dental Equipment Fixation & Instrumentation IOHC www.vetinst.com Surgical Technique Summary • A combined medial and lateral approach is made to the condyles Incomplete ossification of the humeral condyles (IOHC) is a problem most commonly seen in English Springer Spaniels and occasionally in other breeds. The condition is characterised by a failure for the condyles to fuse together and may contribute to forelimb lameness and condylar fracture. • A 2.0mm transcondylar pilot hole is drilled medio-laterally • The VTB custom step drill is used from the medial side to create a seating for the VTB IOHC screw • The VTB screw is inserted using a 3.5mm hex screw-driver from the medial aspect 4.5 Shaft Screws and IOHC • Before the screw-head engages, DBM Putty is injected through a 16G needle into the screw hole beneath the screw-head from the medial aspect • The screw is driven until it becomes tight A comprehensive user guide is available upon request and will be issued with any purchases. As part of a multi-centre prospective study, details of all patients undergoing surgery using this new and novel technique should be recorded and submitted to either John Innes (john.innes@cvsvets.com) or Ben Walton (ben.walton@chestergate.org.uk). IOHC SCREW Thanks to Andy Moores VTBIOHC32 VTBIOHCDRILL DBMPUTC1101 H090102 S090102S TS00045 SDH3500 Until such time as we are able to reliably stimulate the humeral condyles to fuse together, it seems that the only practical means of managing the problem is to place a large trans-condylar stabilising screw. In that the incidence of fatigue failure is high, it seems sensible to use the strongest screw possible. We have manufactured a range of 4.5mm shaft screws from 32mm to 44mm specifically for this procedure. VTB IOHC Screw 32mm long, titanium VTB IOHC Step drill VTB DBM Putty 2.0mm pilot drill, round shank, 100mm long 2.0mm pilot drill, AO quick release, 100mm long 4.5mm cortical tap, AO quick release 3.5mm hex screwdriver £159.65 £262.65 £118.45 £16.75 £21.50 £66.95 £92.19 Andy Moores advises that the 4.5mm Shaft Screw has an AMI (bending resistance) 5 times greater than a standard 4.5m cortical screw. Drill Stops 4.5 SHAFT SCREWS SHSC4532 Shaft Screw SHSC4534 Shaft Screw SHSC4536 Shaft Screw SHSC4538 Shaft Screw SHSC4540 Shaft Screw SHSC4542 Shaft Screw SHSC4544 Shaft Screw SHSC4534TI Shaft Screw SHSC4536TI Shaft Screw 32mm 34mm 36mm 38mm 40mm 42mm 44mm 34mm Titanium 36mm Titanium Placement of the screw is however a challenge in that the gliding hole has to cross the fissure to penetrate into the far condyle. This may be achieved by imaging or by careful pre-measurement and the use of drill stops. £19.83 £19.83 £19.83 £19.83 £19.83 £19.83 £19.83 £28.33 £28.33 DRILL STOPS DRILLSTOP Drill Stop Set in Stainless Case £98.00 Premium Countersinks Maximising contact area between screw head and bone minimises the risk of inadvertent condylar fracture, improves screw stability, reduces the risk of screw head subsidence and reduces the risk of screw loosening. Most countersinks create a conical recess allowing screws to be recessed. These conical countersinks do not perfectly cradle the hemi-spherical heads of standard screws. Our range of premium countersinks are size-matched to our screws. AO quick release fitment. For the full range see page 102. IOHC Screw from Veterinary Tissue Bank These titanium self-compressing screws have been developed by Veterinary Tissue Bank (VTB) for use alongside DBM Putty for the compression and fusion of IOHC fissures in Springer Spaniels. They can also be used for the repair of inter-condylar fractures in similar sized dogs. 8 week follow-up of a Springer Spaniel with IOHC showing boney union in the proximal part of the IOHC fissure either side of the implant (image courtesy of Mark Straw) PREMIUM COUNTERSINK COUPREM4565 Premium Countersink 4.5/ 6.5mm £85.00 Cortical Nuts When threads strip or where bone density is poor, a stainless steel or UHMWPE cortical nut can be used to provide thread anchorage and salvage the situation. Stainless steel nuts are stronger, but UHMWPE is self-locking. For the full range see page 124. The screws are self-tapping, though tapping with a 4.5mm tap may be necessary in particularly sclerotic bone. The mid-section of the screw is of smaller diameter than the hole created by the step-drill creating a void which accommodates the DBM Putty such that vascular invasion and osteoinduction are encouraged. CORTICAL NUTS N45 CN45 4.5mm Cortical Nut Stainless Steel - Sterile 4.5mm Cortical Nut - Sterile £17.00 £10.82 Insert Sleeves Used for centering a pilot hole after drilling a guide hole when placing a lag screw. See page 102 for full range. IOHC screw and custom step drill for insertion 120