Fracture Friday (GSD 9mth distal tibial spiral + fibula - displaced)

RE: Fracture Friday (GSD 9mth distal tibial spiral + fibula - displaced)

Beats — Mon, 10 Dec 2018 20:37:47 GMT

RE: Fracture Friday (GSD 9mth distal tibial spiral + fibula - displaced)

James Dunne — Sat, 08 Dec 2018 07:53:50 GMT

Hi David

With regard to patient fracture assessment scores and whether I use this methodology: I do. I'm ashamed to say it, but in days gone by I was guilty of taking a glance at a fracture radiograph and thinking - or saying - 'this needs X' and then wondering why occasional repairs did not turn out as they should have. In a busy practice with many distractions, it helps me take a step back and be more rational. I think it has helped focus my mind a bit more; subjectively I think I have less complications following fracture repairs and I don't think this is just down to experience and caseload. The PFAS methodology is possibly most useful for people starting off their fracture repair careers to prevent cases being taken on that would best be referred and to reduce the number of animals we harm on our learning curves and also prevent confidence in repair technique being shredded by bad results.

Kind regards

James

RE: Fracture Friday (GSD 9mth distal tibial spiral + fibula - displaced)

Beats — Sat, 08 Dec 2018 07:43:41 GMT

Thanks for all the advice!

lag screws through a plate sounds the best plan. I'm not at all confident I can contour this nicely at very distal tibia and get one or 2 screws through both cortices of the tibia however without risking me accidently penetrating joint. If there's not at least one full screw below fracture line in distal fragment (and I make it only 9mm to joint from distal aspect of fracture line) then I guess it's just a glorified lag screwing adorned by a plate?

Thankfully, however, it's emerged that there's money to fix this so the plate will be applied by an experienced bone-plating vet and not a weekend-hobbyist. His view was that lag screwing with cast would have been the most reasonable alternative to proper plating. I'll try to post the post-op radiographs if I get a copy of them.

RE: Fracture Friday (GSD 9mth distal tibial spiral + fibula - displaced)

David Mills — Fri, 07 Dec 2018 23:38:18 GMT

[quote user="James Dunne"]Best approach for this is lag screws through a plate.[/quote]

I agree with this.

If you're worried about alignment and limb length, some recommend reconstructing and temporary cerclage wires, can apply the plate (or at least seat it in both fragments) over the top then remove, or leave in situ, but the less metal work around the tibia the better.

I plate most of my tibial fractures now, and I am a huge fan of IM pins and cerclage wires (I presented an audit of our comminuted fractures fixed with pin and wire(s) at BSAVA 2y ago, with excellent results); however this one is not suitable for the reasons James outlines. Also plating a tibia is almost as quick as pinning and wiring. BUT don't discount pins in suitable young animals (esp if finances tight) - the callus they form 2 weeks post op does a lot to neutralise the rotational forces (provided sufficient rest).

[quote user="James Dunne"]I would recommend to carefully do a 'fracture assessment score' for this case.[/quote]

Out of interest, do you routinely use these? I am very undecided on them generally.

RE: Fracture Friday (GSD 9mth distal tibial spiral + fibula - displaced)

James Dunne — Fri, 07 Dec 2018 13:48:02 GMT

For me, the distal fragment is fairly short to incorporate an IM pin and achieve good distal seating of it. You could also consider a more cranial plate after lag screw fixation - it looks from the radiographs that you can get two screws in the segment distal to the fracture without penetrating the joint or consider two smaller orthogonal plates. mechanically very robust, but it is getting into pretty tricky surgery. Circular ESF would work fine as well following lag screw reduction to neutralise forces acting on the fracture repair, but you are then getting into difficult surgery with a fair degree of aftercare in a hyperactive patient. I would avoid cerclage wire if lag screws are possible, especially where the distal tibia flares - the wire is much more likely to loosen, even if applied well and lag screws are far more secure.

RE: Fracture Friday (GSD 9mth distal tibial spiral + fibula - displaced)

Dinu Catilina — Fri, 07 Dec 2018 13:11:13 GMT

James, would you consider maybe an IM pin and a locking plate applied medially? I am always worried in large dogs that the lag screws may back out or loosen in the distal fragment.

RE: Fracture Friday (GSD 9mth distal tibial spiral + fibula - displaced)

Beats — Fri, 07 Dec 2018 13:07:25 GMT

Thanks James.

If using a craniomedially-applied DCP, I'm not convinced i could personally safely get a single screw through 2 x cortices of the distal fragment (as opposed to crossing fracture line with lag screws). Is it OK to just cross fracture with lag screws through the plate or would you reckon that is still opting for a weak repair?

I don't have locking plates (though I'm not sure they would make things better? Fixed angle screw distally more likely to penetrate joint?)

EDIT - here's the abstract of the study that would make me question an IM pin adding anything to cerclage wires here [I'm not saying that means cerclage wires are a good option at all, just posting what made me wonder about if doing IM-pin-cerclage then skipping the IM pin in favour of some lag screws might make sense]:

Summary

Objective:

To compare the

in vitro

biomech-

anical effects of single loop cerclage wires,

an intramedullary pin and the combination

thereof as applied to an oblique mid-diaphy-

seal osteotomy of canine tibiae.

Methods:

Three groups of nine bones with

long oblique osteotomies were repaired with

the following methods: 1) Three single loop

cerclage wires and a transcortical skewer pin,

2) intramedullary pinning with a smooth

Steinmann pin, and 3) a combination of both

methods. The repaired constructs were tested

in a single cycle four-point-bending test to

failure. Load displacement curves were

drawn and the following parameters were

calculated or extrapolated: Stiffness, load at

yield, and force resisted at 2 mm actuator

displacement. The latter was determined to

demonstrate the difference in the amount of

energy absorbed between the different

groups.

Results:

The stiffness and force resisted at 2

mm displacement of the groups with cer-

clage wires were significantly higher than the

group with an intramedullary pin alone (p

≤

0.05). The differences in stiffness (p = 0.15)

and force required at 2 mm displacement (p

= 0.56) between cerclage wires and the com-

bination of cerclage wires and intramedullary

pins were not significant.

Clinical relevance:

Cerclage wire repair re-

sults in higher stiffness than repair with an

intramedullary pin. When cerclage wires are

combined with an intramedullary pin, the in-

tramedullary pin does not provide protection

to the cerclage wire repair and the wires or

the bone under the wires has to fail before

the pin resists significant load.

VCOT (2014) 27(2), 91-96.

would be interested in your thoughts on that paper in general (apart from this case)

RE: Fracture Friday (GSD 9mth distal tibial spiral + fibula - displaced)

James Dunne — Fri, 07 Dec 2018 12:56:10 GMT

I would recommend to carefully do a 'fracture assessment score' for this case. The biology is good - it's a closed, low-energy fracture in a young patient. The tibia isn't the best bone to fracture in terms of soft tissue coverage, but it's not the worst either. The mechanics are okay - the fracture is load-sharing if it is reconstructed properly. However, it is juxta-articular [high motion unit close to fracture edge] and 'typical of that signalment' translates as 'nutcase' so it is unlikely to remain as anatomically correct as it is currently. If the clients are good, the dog might still undo their efforts with external coaptation. Best approach for this is lag screws through a plate. It would be possible to do this with minimally invasive surgery in skilled hands and the result should be excellent. Lag screws/cerclage without significant other support [more than a cast] is contra-indicated and shearing forces will destroy them unless you are lucky. If it was a very quiet animal, maybe, but why do surgery if you have to co-apt a weak repair....if the fracture needs to be opened, fix it robustly.