VCOT March 2026 – Ortho Part 1: Feline Bandages, 3D-Printed Locking Plates & THA Cup Positioning

In this Simini Small Animal Surgery Podcast episode, we begin our orthopedic coverage from the March 2026 issue of Veterinary and Comparative Orthopaedics and Traumatology (VCOT) by examining how small technical decisions can profoundly influence orthopedic outcomes—from postoperative care to implant manufacturing and intraoperative accuracy. 

This episode explores whether routine postoperative bandaging is truly beneficial in cats, how 3D-printed locking plates may reshape the future of patient-specific implants, and a novel device designed to improve acetabular cup positioning during canine total hip replacement.

In this episode:

✅ Clayton et al. — A multicenter retrospective study of 152 cats undergoing clean orthopedic procedures evaluated complications associated with postoperative external coaptation. Overall, 68.4% of cats developed bandage-associated complications, and those receiving rigid splints were 3.4 times more likely to experience severe complications than cats managed with soft padded bandages alone. Cases included pressure necrosis, implant exposure, osteomyelitis, and even digit amputation. The findings suggest that when rigid internal fixation provides adequate stability, routine postoperative splinting may introduce unnecessary risk rather than additional protection. 

✅ Kang et al. — Investigated whether locking screw threads can be manufactured directly into 3D-printed titanium plates, eliminating the need for expensive post-machining. When printed in a 0° horizontal orientation, directly printed locking threads achieved push-out strength equivalent to commercially machined plates. However, vertically printed implants demonstrated significant thread defects, and insertion torque proved critical—100% of printed threads failed when tightened to 2.0 Nm, while 1.1 Nm provided reliable fixation. The study highlights how implant manufacturing parameters and surgical technique must evolve together as patient-specific implants become more common. 

✅ Karlin et al. — Evaluated the Cup Position Assessment Device (CPAD), a 3D-printed intraoperative guide designed to objectively measure acetabular cup orientation during canine total hip arthroplasty. Using embedded radiopaque crossbars and intraoperative radiographs, the device measured the angle of lateral opening (ALO) with remarkable accuracy—within approximately 1.1° of the true angle. Although version measurements remain limited by implant overlap on radiographs, the CPAD represents an important step toward objective intraoperative implant positioning and reducing postoperative luxation risk. 

Together, these studies reinforce an important orthopedic principle: better outcomes often come from improving the small details that surround surgery—not just the operation itself.

🎓 Journal Articles Discussed

• Clayton et al. — Incidence of Bandage-Associated Complications in Cats following Clean Orthopaedic Procedures: A Retrospective Study of 152 Cases
• Kang et al. — Feasibility of Integrating Locking Plate System into Additively Manufactured Implants: A Mechanical Comparison of Three-Dimensional-Printed and Machined Locking Hole Threads
• Karlin et al. — In Vitro Evaluation of a Device to Assess Acetabular Cup Position by Sagittal Plane Radiography

📚 From the March 2026 issue of VCOT

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 https://www.simini.com/evaluation-kit

Transcript

SPEAKER_01 0:04

Hi, I'm Carl Damiani, and this is the Simony Small Animal Surgery Podcast, your fast focused update on what matters most from the latest small animal surgical literature. In each episode, we break down key articles from the veterinary journals and translate them into surgical insight you can use today, not someday. This episode kicks off our orthopedic coverage from issue 2, 2026 of Veterinary and Comparative Orthopedics and Traumatology with three studies spanning postoperative care, implant innovation, and clinical orthopedics. First, we'll review a multi-center study by Clayton et al. examining bandage-associated complications in more than 150 cats following clean orthopedic procedures. The results challenge some common postoperative practices and highlight which patients may be at greatest risk for significant bandage-related complications. Next, Kang et al. explore the future of patient-specific implants by asking whether locking plate threads can be manufactured directly into three D printed titanium implants. We'll look at how printing orientation, screw torque, and insertion angle influence mechanical performance and what this could mean for custom orthopedic implants in the years ahead. Finally, we'll discuss the clinical study by Carlin et al. Exploring its practical implications for orthopedic surgeons and how its findings may influence everyday decision making and practice. Three very different studies, one common theme, refining every stage of orthopedic care from post-operative management and implant technology to evidence-based clinical decision making. Let's dive in.

SPEAKER_02 1:47

I've So if you spend any time in veterinary surgery, you already know that bandaging a cat post-op often feels well like trying to wrap water in paper.

SPEAKER_03 1:58

Right. It's incredibly frustrating.

SPEAKER_02 2:00

Yeah, exactly. I mean, half the time the patient has wiggled out of it before they're even, you know, fully awake.

SPEAKER_03 2:05

Which is exactly why this new retrospective study, Clayton et al. 2026, is such a fascinating read for our deep dive today.

SPEAKER_02 2:12

Yeah, let's get into it. What was the setup?

SPEAKER_03 2:14

Well, they looked at 152 client-owned cats with clean orthopedic injuries. The goal was to figure out if routine external coaptation, so things like splints and soft padded bandages, is actually helping recovery or uh secretly sabotaging it.

SPEAKER_02 2:31

Aaron Powell Sabotaging really feels like the right word here, honestly. Because out of those 152 cats, an incredible 68.4% developed a bandage-associated complication.

SPEAKER_03 2:41

Yeah, a massive number.

SPEAKER_02 2:42

But wait, I do have to challenge that number just a bit. Are we just counting like ruffled fur and slightly soiled bandages? Because traditionally a splint is supposed to be the ultimate safety net for a surgical repair, right?

SPEAKER_03 2:52

Aaron Powell I mean, you're right that a lot of those complications were mild, you know, superficial skin irritation or just the slipped bandage.

SPEAKER_02 2:58

Aaron Powell Okay, that makes sense.

SPEAKER_03 2:59

But here is the kicker. If the cat had a splint placed, they were 3.4 times more likely to suffer a severe complication compared to just a soft bandit.

SPEAKER_02 3:09

Wait, 3.4 times? That's not a rounding error. That is huge. Exactly. But why is the splint the primary villain here? I mean, is it just too rigid for feline anatomy?

SPEAKER_03 3:21

Pretty much, yeah. Cats have this really thin, delicate skin and very specific limb contours. Right. So when you place a rigid splint, it creates these relentless, localized pressure points. That pressure restricts blood flow, which leads directly to ischemia and tissue necrosis.

SPEAKER_01 3:39

Oh wow.

SPEAKER_03 3:40

Yeah, in one case in the study, that bandage-induced swelling actually caused plate exposure and osteomyelitis. Seriously. And in another, a cat needed a digit amputated just because of the necrosis from the splint.

SPEAKER_02 3:51

That is just terrifying. You put on a splint to protect a repaired bone and you end up losing a toe.

SPEAKER_03 3:56

Yeah, it's a terrible outcome.

SPEAKER_02 3:58

I would assume, though, like having a board certified specialist apply it rather than a tech might mitigate that risk somewhat.

SPEAKER_03 4:05

Surprisingly, no.

SPEAKER_02 4:06

Really?

SPEAKER_03 4:07

Yeah, the data showed that whether a nuron or a specialist applied the bandage, the severe complication rate didn't significantly change.

SPEAKER_02 4:14

Oh wow.

SPEAKER_03 4:15

And the duration didn't matter much either. It turns out the rigid splint itself was the inherent risk factor.

SPEAKER_02 4:22

That completely flips the script on how we think about post-op protection. I mean, we're relying on these traditional safety nets in the OR, assuming they are safeguarding the patient.

SPEAKER_03 4:31

Right, exactly.

SPEAKER_02 4:32

But the data shows they are actively introducing new hazards. It actually reminds me a lot of how we handle surgical site closure itself.

SPEAKER_03 4:40

Oh, that's a perfect parallel. Because just like we assume a splint protects the limb, we just kind of assume a standard saline lavage protects the wound from infection.

SPEAKER_02 4:50

Yeah, we do.

SPEAKER_03 4:51

But independent head-to-head studies show saline actually leaves 42% of bacteria behind right before you suture.

SPEAKER_02 4:57

Aaron Powell Which is basically like washing half the dishes and calling the kitchen clean. I mean, why is saline failing so badly there?

SPEAKER_03 5:05

Well, because saline is just a mechanical flush. I mean, it washes away loose debris, sure. Right. But it does absolutely nothing to break down the sticky biofilms or, you know, eliminate resistant bacteria clinging to the tissue. Uh-huh. That's why Simony Protect Lavage is really stepping in to replace that step. It's a non-antibiotic lavage you use just before closure.

SPEAKER_02 5:28

Aaron Powell And how did it perform in those studies?

SPEAKER_03 5:30

In those same head-to-head studies, it left zero percent of bacteria behind. Aaron Powell.

SPEAKER_02 5:35

Okay. So it's actively targeting what saline just washes right over. Exactly. And since it's just a 60-second swap at the point of closure, you know, you're not adding 15 minutes to an already long primary or revision surgery.

SPEAKER_03 5:47

Trevor Burrus, Jr. Precisely. You really just use it to reinforce the closure protocol you already have in place.

SPEAKER_02 5:51

Aaron Powell Okay. So for you listening, thinking about your next feline orthocase tomorrow morning, the clinical takeaway from Clayton at all is pretty definitive, right?

SPEAKER_03 6:00

Yeah. Surgical dogma has to evolve.

SPEAKER_02 6:02

Evolve how, specifically.

SPEAKER_03 6:04

Aaron Powell Well, if you are using modern size-appropriate internal fixation that provides rigid stability, your reliance on external co-aptation should drop significantly.

SPEAKER_02 6:14

Makes sense.

SPEAKER_03 6:15

You really need to reconsider routine postoperative splinting in cats if your hardware is doing its job.

SPEAKER_02 6:21

So trust your internal fixation, drop the outdated external safety nets that cause ischemia, and maybe use a modern closure tool like Semini to ensure the site is truly clean.

SPEAKER_03 6:30

Right. It really makes you wonder about the rest of our standard procedures, honestly.

SPEAKER_02 6:34

Oh, for sure.

SPEAKER_03 6:35

If nearly 70% of feline patients experience a complication from a supposedly protective measure, at what point does our clinical safety net actually become the hazard?

SPEAKER_02 6:45

Man, that is enough to make you second guess every routine habit in the OR. Well, thanks for joining us on this deep dive today, and definitely check out the show notes to read Clayton et al.

SPEAKER_00 7:02

Here's the next article.

SPEAKER_03 7:09

So if you're a small animal vet surgeon, you know the feeling. You're looking at a post-up radiograph of a complex bone tumor case, just uh praying those friction screws hold in pathologic bone.

SPEAKER_02 7:20

Oh, absolutely. It's incredibly stressful.

SPEAKER_03 7:22

Right, which is exactly why the veterinary field needs better patient-specific implants. I mean, machine titanium locking plates are the gold standard, sure. Aaron Powell, Jr.

SPEAKER_02 7:30

But they come with that really slow, wildly expensive post-machining step.

SPEAKER_03 7:34

Aaron Ross Powell Exactly, just to cut the locking threads. So our mission today is to pull the clinical punchlines from a recent study that looks at bypassing that step altogether.

SPEAKER_02 7:42

Aaron Powell Yeah, we're looking at Kang et al. 2025. They asked a really crucial question. Can we just directly 3D print those tiny complex locking threads right into the plate?

SPEAKER_03 7:52

Like skipping the machining phase entirely.

SPEAKER_02 7:54

Right, and still actually get a lock that's strong enough for the OR.

SPEAKER_03 7:58

Because, I mean, printing titanium sounds straightforward until you realize the physics of how the printer lays down that metal completely dictates its strength.

SPEAKER_02 8:05

Yeah, so the study tested directly 3D printed TISIX L4V locking threads for a 3.5 millimeter system, and they pitted them against a highly reliable commercially machine system, specifically ARIX.

SPEAKER_03 8:20

Okay, and what was the verdict?

SPEAKER_02 8:21

The breakthrough finding is that the print angle is everything. When the implant is printed completely flat, so at a zero degree orientation, the push out strength perfectly matches the machine plates.

SPEAKER_03 8:32

Wow, perfectly matches.

SPEAKER_02 8:34

Yeah, but plates printed standing up at 90 degrees failed dramatically.

SPEAKER_03 8:38

That makes sense though. It's like trying to 3D print a bridge without any supports. To print at 90 degrees, the printer has to build these uh tiny temporary titanium pillars inside the thread to hold up the overhanging metal.

SPEAKER_02 8:49

Exactly. And when the lab snaps those pillars off later, it leaves behind microscopic burrs and divots.

SPEAKER_03 8:54

Which permanently ruins the geometry of the lock. Wait, so let's unpack this for a second. Does this mean, as a surgeon, you can't just send a CAD file to the lab and trust their default settings?

SPEAKER_02 9:04

You really can't.

SPEAKER_03 9:04

Like if they decide to print this thing vertically just to save space on their build plate, your locking mechanism is going to fail in surgery.

SPEAKER_02 9:12

That is the crucial reality here. You have to actively micromanage that detail and specify a zero degree flat build orientation before you approve a PSI.

SPEAKER_03 9:23

That is huge. Okay. So assuming the lab prints the implant perfectly at zero degrees, we're good to go.

SPEAKER_02 9:30

Well, no. That's when the success of the surgery shifts entirely into your hands during insertion. And the quantitative data here is incredibly unforgiving.

SPEAKER_03 9:38

Uh-oh, what are the numbers?

SPEAKER_02 9:40

The sweet spot for insertion torque is exactly 1.1 newton meters. When the researchers pushed that to 2.0 newton meters, 100% of the 3D printed threads either deformed or cold welded.

SPEAKER_03 9:51

Yeah, 100%. Every single one.

SPEAKER_02 9:54

Every single one. Meanwhile, the traditional machine plates survive that exact same force without a scratch.

SPEAKER_03 10:00

That is wild. To put those numbers in perspective for everyone listening, 1.1 newton meters is incredibly light. I mean, it's the kind of torque you achieve with just two fingers on the screwdriver handle.

SPEAKER_02 10:09

Yeah, it's barely anything.

SPEAKER_03 10:10

Right. So if you grab that handle with your whole fist, you know, to crank it down and get that secure, tactile feel we all love, you're almost certainly hitting 2.0 and destroying the lock.

SPEAKER_02 10:21

Absolutely.

SPEAKER_03 10:22

But why the massive difference? I mean, both plates are titanium, right? Are the days of hand tightening just completely over for 3D printed PSIs?

SPEAKER_02 10:30

They really are. And the reason is that 3D printed metal is built layer by layer. So its surface is microscopically rougher than high-pressure forged machine metal.

SPEAKER_03 10:42

Ah, so it's a friction issue.

SPEAKER_02 10:43

Exactly. When you crank down on that rougher surface, the friction creates immense heat and pressure. The titanium screw literally fuses to the plate.

SPEAKER_03 10:50

Oh wow. So that's the cold welding.

SPEAKER_02 10:53

Right. And if you are angulating the screw, which they tested up to 15 degrees, by the way, hitting that precise 1.1 newton meter torque becomes even more mandatory.

SPEAKER_03 11:01

Because of the angle.

SPEAKER_02 11:02

Yeah, low torque combined with angulation causes a massive drop in push-out strength. A torque limiter is simply non-negotiable here.

SPEAKER_03 11:09

So the clinical punchline for you today isn't just a blanket recommendation to buy a torque limiter. It's understanding that 3D printed metal plays by entirely different rules.

SPEAKER_02 11:18

Directly 3D printed locking plates are a viable, cost-saving reality for your praxis right now.

SPEAKER_03 11:24

Provided you dictate that zero-degree print orientation to the lab.

SPEAKER_02 11:28

Exactly. And in the OR, you have to respect the material, target 1.1 newton meters, and abandon the old habit of hand tightening, especially on angled screws.

SPEAKER_03 11:38

Right. Which leaves us with a pretty provocative thought. If 3D printed titanium, you know, one of the strongest alloys we have, is this mechanically sensitive to a surgeon's torque compared to machine titanium. Yeah. How radically will our surgical techniques need to evolve when we inevitably transition to 3D printing implants from even softer bioabsorbable materials?

SPEAKER_02 11:58

Oh, that's a whole different ballgame.

SPEAKER_03 12:00

Something to think about the next time you're closing up.

SPEAKER_00 12:07

Here's another useful insight from the literature.

SPEAKER_02 12:16

Um, you know that feeling when you are hanging a heavy mirror and you decide to just like eyeball it instead of grabbing a spirit level?

SPEAKER_03 12:23

Oh, yeah. You think it looks totally fine until you finally step back.

SPEAKER_02 12:26

Right. And by then you've already drilled these giant holes in your drywall.

SPEAKER_03 12:30

It is just a sinking feeling. And I mean, if we translate that to the operating room, fixing that kind of misalignment is a massive invasive headache for everyone involved.

SPEAKER_02 12:40

Exactly. So today we are bringing that exact tension right into the surgical suite. We're looking at a paper that could be, well, a total game changer for small animal veterinary surgeons.

SPEAKER_03 12:50

Yeah, we are talking about Carlin et al. 2026.

SPEAKER_02 12:53

Right. Our mission here is to unpack how we can actually prevent postoperative luxation in canine total hip arthoplasty, or you know, THA.

SPEAKER_03 13:03

Which is so critical because when you look at current THA complication rates, they sit somewhere between 7% and 22%.

SPEAKER_02 13:09

Yeah, and luxation makes up the bulk of that, right? At like 2%, 8%. So it's clear something in the process needs a serious upgrade.

SPEAKER_03 13:16

Absolutely. And the main culprit behind those luxations is almost always malposition of the acetabular cup.

SPEAKER_02 13:22

Aaron Powell Like specifically getting the angles wrong.

SPEAKER_03 13:25

Yeah, specifically the angle of lateral opening the ALO or, you know, messing up the open face version.

SPEAKER_02 13:30

Aaron Powell The real frustration for surgeons is that interoperative assessment of these angles is just painfully subjective right now.

SPEAKER_03 13:38

Aaron Ross Powell It really is. You are basically staring at the truncated portion of the cup and the surrounding anatomical landmarks while the patient is right there on the table.

SPEAKER_02 13:46

Aaron Powell Just trying to guess the exact angle before closing. So it really is exactly like hanging that mirror without the level.

SPEAKER_03 13:52

Perfectly said. You don't actually know it's off until you look at the post-op x-ray.

SPEAKER_02 13:56

Aaron Powell So how does this new tool from Carlin et al. get us past just eyeballing it? I know it's called the cup position assessment device or uh C pad.

SPEAKER_03 14:06

Right, the C pad.

SPEAKER_02 14:07

But what is it mechanically doing in the OR?

SPEAKER_03 14:09

Aaron Ross Powell Well, it's a remarkably simple piece of engineering, actually. The C pad is this 3D printed dental resin insert that just drops directly into a BFX cementless cup during surgery.

SPEAKER_02 14:20

Okay, so a resin insert.

SPEAKER_03 14:22

Yeah. And embedded inside this resin are two 25 millimeter stainless steel crossbars.

SPEAKER_02 14:30

Oh, interesting. So what do you do with those?

SPEAKER_03 14:32

Once it's seated in the cup, you just take a standard lateral radiograph. And by looking at the projected length of those steel bars on the 2D image, you use basic trigonometry to objectively calculate the exact angle of the cup.

SPEAKER_02 14:44

Okay, wait. If we are switching from subjective guessing to this 3D printed device, how much closer does that actually get us to the true ALO?

SPEAKER_03 14:53

It gets you within about 1.17 degrees of the true angle.

SPEAKER_02 14:57

Wow, that is incredibly precise.

SPEAKER_03 14:59

It is. In their in vitro tilt table study that translates to a correlation of 0.9940.

SPEAKER_02 15:05

That's near perfect. Because if I remember correctly, the older ellipse-based radiographic methods, um, they could be off by five degrees or more.

SPEAKER_03 15:13

Easily five degrees, yeah.

SPEAKER_02 15:14

So this new method is almost five times more accurate, which is huge when your safe zone for the ALO is strictly between 35 and 50 degrees.

SPEAKER_03 15:21

Exactly. A five degree error with the old method could easily push a surgeon completely out of that safe window.

SPEAKER_02 15:26

So the CP keeps you securely locked in that window.

SPEAKER_03 15:29

It does for the ALO, but um, there is a major clinical caveat we need to address before anyone just takes this into surgery tomorrow.

SPEAKER_02 15:36

Wait, you mentioned there were two crossbars in the resin, right? One for the ALO and one for the open focus version.

SPEAKER_03 15:41

Right. Exactly.

SPEAKER_02 15:42

I understand how you'd clearly see the ALO bar, but if this cup is deeply seated in the acid tabulum, doesn't the titanium implant itself kind of get in the way of seeing that second bar on a 2D X-ray?

SPEAKER_03 15:54

Yes. That is the exact problem they ran into.

SPEAKER_02 15:57

Oh, really?

SPEAKER_03 15:57

Yeah. While the ALO calculation was highly accurate, the open face version calculations essentially failed clinically.

SPEAKER_02 16:03

Aaron Powell Because of the titanium.

SPEAKER_03 16:05

Right. On the radiographs, the metal edge of the titanium cup superimposed over the 25mm V'c crossbar, the one used for version. The shell effectively swallowed the ends of the bar on the image.

SPEAKER_02 16:16

Aaron Powell But I mean, if you just lose a tiny fraction of the bar's tip on the X-ray, does that really ruin the whole calculation?

SPEAKER_03 16:23

It does because the calculation relies on trigonometric curves which are not linear.

SPEAKER_02 16:28

Oh right. The math gets messy.

SPEAKER_03 16:31

Exactly. At a neutral zero degree version, you are at the absolute steepest part of the sine curve.

SPEAKER_02 16:37

Aaron Powell Meaning any error is magnified.

SPEAKER_03 16:39

Hugely magnified. This means even if the titanium edge obscures a minuscule like 0.1 millimeters of that crossbar, the math exponentially magnifies that visual error.

SPEAKER_02 16:51

Aaron Powell Wow. So 0.1 millimeters translates to what?

SPEAKER_03 16:55

A fraction of a millimeter visually translates into a massive two-degree swing in the final calculation.

SPEAKER_02 17:01

Wow. So the math is just too fragile there.

SPEAKER_03 17:03

Yeah.

SPEAKER_02 17:03

Because of that metal overlap, the version measurement isn't something a surgeon can rely on right now. Aaron Powell Right.

SPEAKER_03 17:08

We just can't trust it for version yet. But because the ALO measurement doesn't suffer from that same visual overlap, the practical application remains incredibly strong.

SPEAKER_02 17:16

Aaron Powell So you could still use the CPAD to objectively verify and adjust your ALO placement interoperatively.

SPEAKER_03 17:23

Exactly. You're getting highly accurate data before wound closure, which shifts the entire paradigm from, you know, post-operative reaction to interoperative prevention.

SPEAKER_02 17:32

Aaron Powell And that alone could save your patient from an invasive painful revision surgery. It's amazing that something as basic as a resin mold with two steel bars can fundamentally elevate surgical confidence in the OR.

SPEAKER_03 17:44

It really is elegant in its simplicity.

SPEAKER_02 17:47

Definitely. I want to leave you with this thought today. If this simple device already nails the ALO so perfectly, where do we go from here?

SPEAKER_03 17:55

That's the exciting part.

SPEAKER_02 17:57

Right. Like, could future iterations utilizing radioloos and cup edges prevent that visual overlap entirely? Right. Or maybe AI-assisted image analysis could solve the version measurement math.

SPEAKER_03 18:08

Both are very possible.

SPEAKER_02 18:09

Imagine having a flawless digital spirit level for every single total hip replacement so that when you finally step back from the surgical table, you know the alignment is absolute perfection.

SPEAKER_01 18:23

That's it for this episode of the Simony Small Animal Surgery Podcast. This show is brought to you by Semini Protect Livage, our interoperative lavage developed to target resistant bacteria and biofilms where traditional solutions of saline and post op antibiotics fall short. If you're interested in learning more or trying out your own procedures, you'll find information and links in the show notes. For listening, and we'll see you in the next episode.