Chapter 7 - Veterinary Instrumentation

7 TRAUMA IMPLANTS & INSTRUMENTS4.5mm Cortical Self Tapping ScrewsUse of Self Tapping Screws can save considerable time and trauma.Reducing surgery time will reduce morbidity. Pull out strength is notaffected provided the self tapping flutes lie outside of the cortex.Add an extra 1mm when assessing screw length.Self Tapping Screws are less effective in dense cortical bone.e.g. calcaneus. It is advised that an appropriate tap be availableshould the need arise.Drill data: Pilot Drill 3.2mm Clearance Drill 4.5mm4.5MM CORTICAL SELF TAPPING SCREWS - HEX HEAD=3.5MM PILOT=3.2MMCSST4512 12mm £6.00CSST4514 14mm £6.00CSST4516 16mm £6.00CSST4518 18mm £6.00CSST4520 20mm £6.00CSST4522 22mm £6.00CSST4524 24mm £6.75CSST4526 26mm £6.75CSST4528 28mm £6.75CSST4530 30mm £6.75CSST4532 32mm £6.75CSST4534 34mm £6.75CSST4536 36mm £6.75CSST4538 38mm £6.75CSST4540 40mm £7.25CSST4542 42mm £7.25CSST4544 44mm £7.25CSST4546 46mm £7.25CSST4548 48mm £7.25CSST4550 50mm £7.25CSST4552 52mm £7.25CSST4554 54mm £7.25CSST4556 56mm £8.00CSST4558 58mm £8.00CSST4560 60mm £8.00CSST4562 62mm £8.00CSST4564 64mm £8.00CSST4566 66mm £8.00CSST4568 68mm £8.00CSST4570 70mm £8.00CSST4575 75mm £11.00CSST4580 80mm £13.00CSST4585 85mm £15.004.5 Shaft Screws and IOHCUntil such time as we are able to reliably stimulate the humeral condyles tofuse together, it seems that the only practical means of managing theproblem is to place a large stabilising screw. In that the incidence of fatiguefailure is high it seems sensible to use the strongest screw possible. Wehave manufactured a small range of 4.5 Shaft Screws from 32mm to40mm specifically for this procedure.Andy Moores advises that the 4.5 ShaftScrew has an AMI (bending resistance) 5times greater than a standard 4.5 corticalscrew. Placement of the screw is, howevera challenge in that the gliding hole has tocross the area of IOHC to penetrate intothe far condyle. This may be achieved byimaging or by careful pre-measurementand the use of Drill Stops.Thanks to Andy Moores for the picture.4.5 SHAFT SCREWSSHSC4532 Shaft Screw 32mm £18.50SHSC4534 Shaft Screw 34mm £18.50SHSC4536 Shaft Screw 36mm £18.50SHSC4538 Shaft Screw 38mm £18.50SHSC4540 Shaft Screw 40mm £18.50SHSC4542 Shaft Screw 42mm £18.50SHSC4544 Shaft Screw 44mm £18.50SHSC4534TI Shaft Screw 34mm £26.50SHSC4536TI Shaft Screw 36mm Titanium £26.50Extra Length DCPsAlthough these seem very long, they are a popular request as moresurgeons come to understand the mechanical benefits of spanning thewhole bone — something we are commonly also forced into where there isa very large zone of comminution.In addition, if the central area where the DCP holes change direction onthe plate is kept over a fracture line and the fracture line is offset to oneend of a bone, a number of holes may need to be sacrificed on the side ofthe shorter fragment, resulting in a much shorter plate than before. Theusefulness of the extra length to start with suddenly becomes obvious.Where DCPs are used for arthrodesis and more than one bone isspanned, the extra length should again prove very helpful.Our longest DCPs…1.5/2.0 CP201892 18 Hole 92mm2.4 C2416115 16 Hole 115mm2.7 C2718148 18 Hole 148mm3.5 C3520242 20 Hole 242mm3.5B BC3522266 22 Hole 266mm4.5 C4520327 20 Hole 327mm4.5B B4518295 18 Hole 327mm184