VCOT September 2025 – Ortho Part 2: Toy Breed Menisci & Growth-Guided Tibial Plateau Correction

In this Simini Small Animal Surgery Podcast episode, we continue our orthopedic coverage from the September 2025 issue of Veterinary and Comparative Orthopaedics and Traumatology (VCOT) by examining how biology and biomechanics shape long-term orthopedic outcomes in small dogs.

One study challenges assumptions about meniscal injury prevalence in toy-breed dogs with cranial cruciate ligament disease, while the second explores how growth itself may become a powerful ally in the treatment of proximal tibial physeal fractures.

In this episode:

✅ Kikuchi et al. — Used arthroscopy to evaluate the incidence of medial meniscal injury in toy-breed dogs weighing 5 kg or less with cranial cruciate ligament rupture. The authors identified meniscal injury in 36.3% of affected stifles, demonstrating that significant meniscal pathology remains common even in very small patients. Yorkshire Terriers showed particularly high rates of complete cruciate rupture and meniscal injury, with over 55% of Yorkies affected. The study highlights the importance of thorough meniscal assessment, especially in dogs with complete ruptures, higher relative body weight, and severe lameness. 

✅ Turner et al. — Evaluated postoperative changes in tibial plateau angle (TPA) following repair of Salter-Harris Type I and II proximal tibial physeal fractures. Across 32 dogs, the authors observed a mean 5.89° reduction in TPA during early healing, demonstrating that significant dynamic correction occurs after surgery. Interestingly, adding a tibial tuberosity tension band did not significantly affect correction, suggesting that cranially placed K-wires alone create sufficient temporary physeal tethering to guide growth and level the tibial plateau over time.

Together, these studies remind us that successful orthopedic surgery requires understanding not only the injury itself, but also how biology continues to influence outcomes long after the procedure is complete.

🎓 Journal Articles Discussed

• Kikuchi et al. — Incidence of Medial Meniscus Injury Detected by Arthroscopy in Toy Breed Dogs (≤5 kg) with Cranial Cruciate Ligament Rupture
• Turner et al. —Tibial Plateau Angle Changes following Repair of Salter–Harris Type 1 and 2 Fractures in Dogs

📚 From the September 2025 issue of VCOT

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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 continues our orthopedic coverage from Issue 5 2025 of Veterinary and Comparative Orthopedics and Traumatology, and we're focusing on two studies that challenge some long-held assumptions about stifled disease and proximal tibial fracture management in small dogs. First, we'll look at a study by Kikuchi et al. who used arthroscopy to investigate the incidence of medial meniscal injury in toy breed dogs weighing 5 kilograms or less with cranial cruciate ligament rupture. The findings provide new insight into just how commonly meniscal damage occurs in these tiny patients, and which clinical factors should raise your suspicion before you ever enter the joint. Then we turn to Turner et al., who evaluated changes in tibial plateau angle following surgical repair of Psalter Harris type 1 and 2 proximal tibial physial fractures. The results suggest that postoperative tibial plateau angles may continue to improve over time, potentially reducing concerns about residual plateau slope immediately after surgery and influencing how we counsel owners during follow-up. Two studies, one common theme, understanding how the biology of growth, injury, and joint stability shapes long-term orthopedic outcomes. From meniscal pathology in toy breed cruciate disease to the dynamic remodeling of the developing tibia, these papers offer practical insights that can influence both surgical decision-making and postoperative expectations. Let's dive in.

SPEAKER_00 2:07

Welcome to today's deep dive. If you are prepping a Yorkshire Terrier for a cruciate rupture repair tomorrow, you know you might actually be walking into a trap.

SPEAKER_02 2:16

Oh, absolutely. It is a very tricky procedure.

SPEAKER_00 2:18

Right. Assessing a stifle joint in a dog under five kilos is just notoriously difficult and kackuchi at all. 2025 reveals just how much pathology we might be leaving behind if we rely solely on gross evaluation during a standard arthrotomy. I mean, it is basically like trying to inspect a watch mechanism through a keyhole.

SPEAKER_02 2:38

That is a perfect analogy. And you know, that paper puts a hard number on the blind spots in those microenvironments.

SPEAKER_01 2:43

Yeah.

SPEAKER_02 2:44

Yeah. By utilizing arthroscopy instead of an open approach, well, they found medial meniscal injury in 36.3% of affected toy breed stifles.

SPEAKER_00 2:54

Wait, really? Over a third?

SPEAKER_02 2:56

Yeah, over a third.

SPEAKER_00 2:57

I mean, a toy breed weighs almost nothing. So does this mean surgeons need to aggressively probe every three kilopoodle's meniscus? How is a tiny dog generating enough compressive force to completely destroy a meniscus? The math just seems off if we are looking at sheer mass.

SPEAKER_02 3:11

Well, it is less about mass and uh much more about altered biomechanics. When that cruciate ligament completely ruptures, the craniocaudal instability is severe. Right. And because the joint is so incredibly small, the tibial subluxation acts less like a sliding joint and more like a mortar and pestle.

SPEAKER_00 3:31

Oh, wow. That paints a picture.

SPEAKER_02 3:33

It does. Every single step physically grinds the caudal horn of the medial meniscus into paste. And you know, the heavier the dog gets within that toy category, the faster that grinding takes a toll.

SPEAKER_00 3:45

So like a heavier toy dog with a complete tear is already a massive red flag before you even make an incision.

SPEAKER_02 3:51

Exactly.

SPEAKER_00 3:51

But looking at the breed breakdown in Kakuchi at all, 2025, it is just wild. 86.7% of the yorkis presented with complete ruptures, and over 55% of them had meniscal injuries.

SPEAKER_02 4:03

It is a massive spike for that specific breed.

SPEAKER_00 4:05

It really is. It sounds like if a Yorkie comes in non-weight bearing, you basically have to treat the meniscus as torn until proven otherwise.

SPEAKER_02 4:11

That is honestly the safest clinical assumption you can make. The data lays out some very clear clinical red flags. So complete rupture, a higher relative body weight, and severe like grade three lameness mean you must evaluate that joint cautiously.

SPEAKER_00 4:27

So you really have to lean on arthroscopy then.

SPEAKER_02 4:29

You do. You need it to find those micro tiers and preserve the joint's future health.

SPEAKER_00 4:34

And I imagine in these microenvironments the margin for error is basically zero. I mean, you can perfectly debride that meniscus via arthroscopy, but because the joint capsule is so tiny, a microscopic bacterial load that a mastiff could easily clear would completely devastate a York's stifle post op.

SPEAKER_02 4:52

Oh, without a doubt. Which means protecting the surgical site during closure is just as critical as protecting the internal structures during the procedure itself.

SPEAKER_00 5:00

Right, the infection control aspect.

SPEAKER_02 5:01

Exactly. We know standard saline lavage fails to clear about 42% of the bacterial load.

SPEAKER_00 5:06

Wow, 42%.

SPEAKER_02 5:07

Yeah, it leaves nearly half behind. That is a massive liability in a toy breed stifle.

SPEAKER_00 5:11

Right. And I think this is where integrating something like Semini Protect Livage really changes the equation. It is a 60-second non-antibiotic reinforcement to your existing protocols.

SPEAKER_02 5:21

It is. And the mechanism is genuinely fascinating.

SPEAKER_00 5:24

Aaron Powell Yeah. It uses surfactant technology to physically break bacterial adhesion. So it is not just washing the joint, you know, it is actively disrupting the biofilm layer.

SPEAKER_02 5:34

Right. So it removes what saline routinely misses. You achieve complete microbial clearance.

SPEAKER_00 5:39

Aaron Powell Leaving 0% of those pathogens behind.

SPEAKER_02 5:42

Exactly, 0%, which is the exact standard you need when closing such a vulnerable site.

SPEAKER_00 5:47

So for your surgical plan tomorrow, anticipate meniscal damage and toy breeds with complete tears or severe lameness. Lean on arthroscopy to catch the hidden pathology. And upgrade your closure protocol to leave 0% of bacteria behind.

SPEAKER_02 6:01

Basically, control the variables you can see and eliminate the microscopic ones you cannot.

SPEAKER_00 6:06

Exactly. Which leaves you with one final thought to ponder today. Kaguchi et al. 2025 showed us that Yorkis suffer from complete ruptures at vastly higher rates than chihuahuas or toy poodles. What unique undiscovered biomechanical flaws in the Yorkies anatomy are driving this accelerated joint degradation, and how might that change how we breed or treat them in the future?

SPEAKER_01 6:30

Here's the next article.

SPEAKER_00 6:36

So picture this.

SPEAKER_02 6:47

Yeah, and you're working with um, what, a minuscule two to four millimeter tibial plateau?

SPEAKER_00 6:53

Exactly. It's tiny, and you're just sweating over the post-op tibial plateau angle or TPA. Because, you know, an excessively high TPA drastically bumps up the risk of a future cranial cruciate ligament rupture.

SPEAKER_02 7:05

Oh, it's a huge stressor. But today we're actually looking at a recent paper, Turner et al. 2025, to see if that angle might dynamically correct itself as the puppy grows.

SPEAKER_00 7:14

Right. And obviously what that means for your actual surgical decision making. So um what was the mission here? What did they look at?

SPEAKER_02 7:21

Well, they did a retrospective review of 32 dogs. And heavily represented by French Bulldogs, actually.

SPEAKER_00 7:26

Oh, interesting.

SPEAKER_02 7:27

Yeah. All of them sustained proximal tubial physial fractures, and the repairs utilized cranially placed K wires.

SPEAKER_00 7:33

Okay.

SPEAKER_02 7:34

And some of those constructs included a tibule tuberosity tension band, while you know others relied on just the K wires alone.

SPEAKER_00 7:41

Okay, let's unpack this a bit. Getting a perfect reduction on a like three millimeter fragment is essentially like threading a needle on a roller coaster.

SPEAKER_02 7:50

That is a very accurate way to put it, yeah.

SPEAKER_00 7:52

Right. So if that initial reduction isn't absolutely perfect, are these dogs just doomed to a permanently high TPA?

SPEAKER_02 8:00

Actually, no. The standout clinical finding was that the TPA dynamically corrected.

SPEAKER_00 8:05

Wait, really? By how much?

SPEAKER_02 8:07

By a mean of 5.89 degrees. So from the time of injury to the first reevaluation at four to eight weeks, it dropped significantly.

SPEAKER_00 8:15

Wow, I mean, nearly six degrees is a massive dynamic shift. But I want to look closely at the implant choices. Did adding that tension band accelerate the angle correction?

SPEAKER_02 8:24

You'd think so, but it actually made no statistically significant difference in TPA reduction compared to using K wires alone.

SPEAKER_00 8:31

Wait, that defies common biomechanical sense, doesn't it?

SPEAKER_02 8:34

How so?

SPEAKER_00 8:34

Well, a tension band adds active compression across that sysis, right? It neutralizes the pull of the patella ligament. So why wouldn't adding that compressive force give you a better or at least faster angle reduction?

SPEAKER_02 8:45

Aaron Powell I mean, it makes sense on paper, but it comes down to what is actually driving the change of the bone. The dynamic TPA correction isn't primarily driven by counteracting muscle pull. Okay, so what is driving it? It's driven by the hardware acting as a physical tether. Intentionally placing those K wires cranially on the tibial plateau creates a localized epiphysiadesis.

SPEAKER_00 9:08

Oh, I see.

SPEAKER_02 9:09

Yeah, the pins physically bridge the cranial aspect of the tibial physis, which basically arrests chondrocyte proliferation.

SPEAKER_00 9:16

Aaron Powell So it attenuates growth on that specific side.

SPEAKER_02 9:19

Exactly.

SPEAKER_00 9:19

It's like um putting a heavy doorstop on just one side of a growing hinge.

SPEAKER_02 9:24

I like that analogy. The K wires lock down the cranial side, but the caudal physis has no hardware restricting it.

SPEAKER_00 9:30

Right. So it continues its normal endochondral ossification.

SPEAKER_02 9:33

Precisely. And that differential growth essentially wedges the plateau level over time.

SPEAKER_00 9:37

Aaron Powell Wow. Okay. So because the K-wires alone provide enough rigidity to tether that cranial growth plate, adding a tension band is It's essentially putting a second lock on a door that's already bolted shut. Ah, got it.

SPEAKER_02 9:50

The tension band might provide overall construct stability, you know, depending on the fracture configuration, but it is not the engine driving the dynamic leveling.

SPEAKER_00 9:58

Aaron Powell Okay, so what is the clinical punchline here? What does this mean for the surgeon who's, you know, evaluating their post-op radiographs tomorrow morning?

SPEAKER_02 10:07

If you achieve an imperfect initial reduction, just don't panic. Do not immediately rush to plan a secondary corrective surgery for a high TPA.

SPEAKER_00 10:16

Because it'll fix itself.

SPEAKER_02 10:17

Right. The angle is highly likely to correct dynamically. However, um, there is a crucial procedural caveat here.

SPEAKER_00 10:25

Aaron Powell There's always a catch. What is it?

SPEAKER_02 10:27

If the patient has significant remaining growth potential, you must remove those K wires around three to four weeks post-surgery.

SPEAKER_00 10:35

Oh, right. Because leaving them in indefinitely would completely arrest that cranial growth.

SPEAKER_02 10:40

Exactly, potentially leading to secondary deformities. You have to remove the hardware to let the bone finish its normal development once the plateau is leveled out.

SPEAKER_00 10:47

So you're basically temporarily using the implants to guide the biology.

SPEAKER_02 10:51

Yeah, but you withdraw them before the mechanical restriction becomes pathological. Setting up the right mechanical environment allows the patient's own growth to become your most effective surgical tool.

SPEAKER_00 11:01

That is brilliant. Definitely keep this clinical intelligence handy for your next fracture repair. Biology will often do the heavy lifting if we let it. Absolutely. But you know, here's a final provocative thought to mull over before your next procedure. Turner et al. 2025 predominantly featured small breeds. Right.

SPEAKER_02 11:20

Yeah, like French bulldogs.

SPEAKER_00 11:21

Right. Breeds with fairly limited growth potential. So, how might this dynamic autocorrection behave in a giant breed puppy?

SPEAKER_02 11:30

Oh, that's an interesting point.

SPEAKER_00 11:32

Could those exact same tethering forces lead to a dangerous overcorrection? It's definitely something to monitor closely in your own post-op radiographs. We'll leave you with that.

SPEAKER_01 11:45

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. Thanks for listening, and we'll see you in the next episode.