Veterinary Surgery Deep Dive: Equine Ortho — May 2026 Edition

In this episode of the Simini Equine Surgery Podcast, we explore the orthopedic research from the May 2026 issue (Issue 4) of Veterinary Surgery, where two studies examine how timing and surgical technique can dramatically influence long-term orthopedic outcomes. 

One study follows nearly 150 Standardbred foals during their first year of life to determine when tarsal osteochondrosis lesions are capable of healing naturally—and when surgery becomes inevitable. The second evaluates diode laser-facilitated ankylosis for distal tarsal osteoarthritis, identifying the surgical technique that best restores athletic performance while minimizing repeat procedures.

In this episode:

✅ McCoy et al. conducted a prospective longitudinal study of 148 Standardbred foals, obtaining serial radiographs every two months from 2 to 12 months of age to evaluate the natural progression of tarsal osteochondrosis (OC). The authors found that 84.5% of lesions that ultimately resolved did so by six months of age, while none of the lesions that progressed to osteochondrosis dissecans (OCD) with fragment separation healed spontaneously. Once a fragment detached, spontaneous healing dropped to 0%, making surgical removal the only effective treatment. Interestingly, gait (trotting versus pacing) had no influence on lesion development or healing, while one farm that housed weanlings instead of allowing pasture turnout demonstrated no radiographic improvement after six months, highlighting the potential importance of exercise and environmental management during skeletal development. The study provides surgeons with a clear decision point: monitor stable OC lesions, but proceed with surgery promptly once fragment separation occurs. 

✅ Sanchez-Arjona et al. reviewed 64 horses treated with diode laser-facilitated ankylosis (DLF) for distal tarsal osteoarthritis over a ten-year period. Overall, 83% of horses experienced clinical improvement, while 64% returned to their previous level of athletic performance. Although three surgical techniques produced similar return-to-work rates, the addition of cuboidal bone fenestration dramatically reduced the need for repeat surgery. Horses treated with laser alone required reintervention in 20.8% of cases, whereas no horses receiving laser combined with cuboidal bone fenestration required a second procedure. By addressing both the joint surface and underlying subchondral bone pathology, fenestration appears to provide more durable long-term results while minimizing recurrent lameness. 

Together, these studies demonstrate that successful orthopedic surgery depends on intervening at precisely the right moment and selecting techniques that address the underlying disease—not simply its visible manifestations.

🎓 Journal Articles Discussed

• McCoy et al. — Natural progression of tarsal osteochondrosis in Standardbred pacers and trotters
• Sanchez-Arjona et al. — Outcomes of diode laser-facilitated ankylosis of the distal tarsal joints in horses: A retrospective study of 64 cases

📚 From the May 2026 Issue (Issue 4) of Veterinary Surgery

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Transcript

SPEAKER_01 0:04

Hi, I'm Carl Damiani, and this is the Simene Equine Surgery Podcast, your fast, focused update on what matters most from the latest equine surgical literature. In each episode, we break down key articles from the veterinary journals and translate them into practical surgical insight you can use. Today, not someday. This episode covers the orthopedic section from the May 2026 issue of veterinary surgery, and we're exploring two studies focused on heck disease across very different stages of a horse's career, from developmental orthopedic disease in young foals to advanced osteoarthritis in performance horses. First, we'll look at a study by McCoy at Al, who followed nearly 150 standard bred foals over their first year of life to better understand how tarsal osteochondrosis develops, heals, or progresses. The findings provide valuable insight into when lesions are most likely to resolve, when they become permanent, and how that timing can influence decisions about monitoring and surgical intervention. Then we'll review Sanchez Arjona et AL, who evaluated diode laser facilitated ankylosis as a treatment for distal tarsal osteoarthritis in horses. By comparing different surgical approaches over long-term follow-up, the study examines which techniques best restore athletic performance while reducing the need for additional procedures, offering practical guidance for managing one of the most common causes of Hindelim lameness. Two studies. One common theme, understanding the natural history of heck disease and choosing the right intervention at the right time. Whether that's allowing a young horse to heal naturally or selecting the most effective surgical strategy for an experienced athlete. Let's dive in.

McCoy et al. Study: Tracking Tarsal Osteochondrosis Development, Healing, and Progression in over 140 Standardbred Foals.

SPEAKER_00 1:55

If you radiograph a standard bread fall at like six months and see a tarsal fragment, what are the exact odds it will heal naturally? Well, zero. Welcome to today's deep dive into actionable clinical intelligence for the AOR, where our mission is to cut the fluff and tell you exactly how McCoy et al. should influence your surgical decisions tomorrow.

SPEAKER_02 2:17

Yeah, that zero percent figure, it completely changes the traditional clinical calculus. Right. Because we are constantly weighing the risks of operating on a young foal against this uh this hope that a tarcel osteochondrosis lesion might just resolve on its own as they grow.

SPEAKER_00 2:33

Right. It is a tough call. I tend to think of an OC lesion kind of like a microfissure in a bridge's structural stress. Like if it is just a stress line, giving it time and offloading weight might let it stabilize. But once a piece of that metal actually chips off and falls into the gears, time isn't gonna fix it.

SPEAKER_02 2:48

Exactly. It is just gonna grind the system down.

SPEAKER_00 2:50

Yeah.

SPEAKER_02 2:51

And that structural comparison captures the exact joint mechanics at play here. So to find out precisely when that clinical fissure becomes a detached fragment, the McCoy study tracked 148

Gait and Biomechanical Stress Profiles: Revealing that video-monitored foals spend barely 1% of their day trotting or pacing, rendering specific gait preferences irrelevant to lesion progression or healing.

SPEAKER_02 3:01

client-owned standard bread foals.

SPEAKER_00 3:04

Wow, that is a really solid sample size.

SPEAKER_02 3:06

Yeah, it really is. They took tarsal radiographs every two months from two to twelve months of age, just monitoring to see if lesions would heal naturally or, you know, progress to true osteochondrosis disciplins with actual radiographic separation.

SPEAKER_00 3:20

You know, going into this data, I assume biomechanics would be the primary driver of that separation. Because you have pacers and trotters, and those gates put vastly different shear forces on the tarsus. I mean, surely that dictates which joints develop OCD, right?

SPEAKER_02 3:35

You would totally think so, but the data completely upends that assumption. Gate preference made absolutely no difference in lesion prevalence or healing.

SPEAKER_00 3:43

Wait, really? None at all.

SPEAKER_02 3:44

None. When the researchers reviewed the video monitoring, they found these foals spent barely 1% of their time actually trotting or pacing. I mean, the biomechanical stress of a specific gate is irrelevant when the foal is essentially just eating or standing around for 99% of the day.

SPEAKER_00 4:00

Okay, that makes a lot of sense. So since they aren't aggressively stressing

Natural Resolution Timeline and Thresholds: Identifying that 84.5% of naturally resolving lesions heal by six months of age, while true radiographic separation drops subsequent healing rates to absolute zero.

SPEAKER_00 4:03

the joints by running, time should theoretically be on their side. And I guess for a lot of them it is, since the data shows that of the lesions that ultimately heal naturally, 84.5% did so by six months of age.

SPEAKER_02 4:16

Right. But here is where the mechanism dictates our surgical approach. Because once an osteochondral fragment physically separates, healing drops to absolute zero.

SPEAKER_00 4:25

It just hits a wall.

SPEAKER_02 4:27

Exactly. The synovial fluid can no longer bridge that physical gap to facilitate osteogenesis. The fragment isn't part of the healing process anymore, it just becomes a purely mechanical irritant within the joint capsule.

SPEAKER_00 4:39

Which gives surgeons a definitive, undeniable threshold for intervention tomorrow. So if you radiograph a full and see an abnormal bone contour on the tarsus, but there is no radiographic separation, hold off. Delaying past 12 months makes clinical sense because it can still heal.

SPEAKER_02 4:56

Yeah, the joint environment can still support natural healing at that stage. But the moment you see a fragment early surgical removal before 12 months is highly recommended. Honestly, it's mandatory. Delaying past that point only guarantees further articular damage.

SPEAKER_00 5:11

Right. But let's be real about the clinical environment here. Every time you open a joint in a young full, you are risking joint sepsis. Introducing infection into a developing joint is a nightmare scenario. So when you do make the call to go in and remove that fragment,

Simini Protect Lavage Study: Addressing the 42% bacterial remainder left behind by standard saline joint flushes versus the 0% baseline achieved by a 60-second surfactant wash to mitigate foal joint sepsis risks.

SPEAKER_00 5:27

reinforcing your closure protocol is critical.

SPEAKER_02 5:30

Oh, absolutely. It's the biggest vulnerability in the surgical workflow. I mean, saline is our standard for joint lavage before closure, but independent head-to-head studies show saline leaves 42% of bacteria behind.

SPEAKER_00 5:41

That is a massive blind spot. Leaving nearly half the bacteria behind is just unacceptable.

SPEAKER_02 5:46

It really is. Saline simply lacks the chemical properties to break through the surface tension of bacterial biofilms that adhere to the cartilage.

SPEAKER_00 5:55

Which is why non-antibiotic options like Semini Protect Livage are gaining traction in these specific orthopedic procedures, right? Because it is designed to physically disrupt the biofilm that saline misses.

SPEAKER_02 6:07

Precisely. Semity drops that 42% down to 0% bacteria left behind. And it reinforces that critical closure step in just 60 seconds, which means you aren't disrupting your existing surgical workflow at all.

SPEAKER_00 6:19

But you are mitigating the exact sepsis risk that makes us hesitant to operate in the first place. You mitigate the risk so you can actually act on the data.

SPEAKER_02 6:27

Exactly. The take-home message from McCoy

The Turnout Factor: Highlighting a stark finding where weanlings managed under strict stall confinement demonstrated zero radiographic joint improvement after six months of age.

SPEAKER_02 6:29

et al 2026 is unambiguous. Monitor those tarsal OC lesions, but the moment a fragment appears, stop waiting and plan for surgery. The joint just cannot fix itself once separation occurs.

SPEAKER_00 6:42

But here is one final detail for you to mull over. We mentioned gate didn't impact healing, but one farm in this study that stalled its weanlings saw zero radiographic improvement after six months of age. None.

SPEAKER_02 6:52

Oh wow, so absolutely no healing if they were stalled.

SPEAKER_00 6:55

Yep, zero. So while we obsess over surgical timing and closure protocols, could simple pasture turnout be the ultimate hidden factor in joint health? Keep an eye on those joints, you know, both in the OR and out in the pasture.

SPEAKER_01 7:11

Now let's take a look at what the next paper shows us.

Sanchez-Arjona et al. Study: Long-Term Retrospective Evaluation of Diode Laser-Facilitated Ankylosis (DLF) for Distal Tarsal Osteoarthritis in Performance Horses.

SPEAKER_02 7:19

Staring at a refractory distal hockoa case is honestly one of the most frustrating moments in equine surgery. You know, you've injected corticosteroids, the horse improved for a bit, and now they've just completely plateaued.

SPEAKER_00 7:31

Yeah, the medical management is totally exhausted at that point. You are basically forced to make a structural decision for a performance athlete.

SPEAKER_02 7:39

Right, exactly. So today we are taking a deep dive into diode laser facilitated ankylosis,

Comparative Reinterventions and Failure: Reviewing a 64-horse, decade-long cohort showing similar 60–68% return-to-athleticism rates across three separate DLF techniques.

SPEAKER_02 7:45

or DLF. We're pulling insights from a retrospective study by Sanchez Arjona et al. 2026 to figure out exactly which DLF approach belongs in your OR tomorrow.

SPEAKER_00 7:56

And they followed 64 client-owned horses over a decade. The baseline results are, well, they're really solid.

SPEAKER_02 8:03

Yeah. I mean, 83% showed clinical lameness improvement, and 64% actually returned to their previous level of competition.

SPEAKER_00 8:09

But there are three different surgical techniques evaluated here, which is where it gets interesting. They looked at intra-articular diard laser alone, which is technique L, then laser with periarticular drilling, and finally laser with cuboidal bone fenestration, or L plus F.

SPEAKER_02 8:25

Wait. Looking at the primary return to athleticism, all three techniques hover right around 60 to 68%.

SPEAKER_00 8:31

Yeah, they're all pretty comparable there.

SPEAKER_02 8:33

So why would a surgeon bother with the extra trauma of fenestrating the cuboidal bones? Like why not just stick to the laser alone and save the time?

SPEAKER_00 8:42

Because um you have to look at the reintervention rates. That's the real differentiator. Technique L alone had a 20.8% rate of requiring a second surgery.

SPEAKER_02 8:52

Aaron Powell Wow. That's like one in five horses coming back to your table.

SPEAKER_00 8:55

Aaron Powell Exactly. One in five. But for the horses that received the laser with fenestration, zero percent.

SPEAKER_02 9:01

Aaron Ross Powell Wait, zero. Not a single horse required reintervention.

SPEAKER_00 9:05

Not a single one. Zero percent versus one in five is just a massive clinical difference.

SPEAKER_02 9:10

Aaron Powell I mean, yeah, that's huge. So using just the laser is essentially fusing the joint space, but it's

Pressure Release Valve Mechanics: Explaining how physical fenestration targets underlying intraosseous disease and bone edema to preserve long-term durability over faster, less stable laser-only paths.

SPEAKER_02 9:16

doing absolutely nothing for the subchondral pressure building up inside the bone itself.

SPEAKER_00 9:20

Exactly. And that's the whole mechanical advantage of the fenestration. It basically acts as a pressure release valve for subchondral bone edema. Yeah, while providing a channel to actually promote that bony fusion, if you just hit the joint with the laser, you're essentially sealing the lid on a boiling pot without turning down the heat.

SPEAKER_02 9:38

That perfectly explains the durability. Though looking at the data, technegel does offer a slightly faster initial recovery, right?

SPEAKER_00 9:46

Aaron Ross Powell, it does. You're often getting them back to work in under a year.

SPEAKER_02 9:49

Aaron Ross Powell But you're basically trading speed for stability then.

Non-Medical Demographic Bias: Dissecting an economic odds ratio anomaly showing males 4.25 times more likely to return to competition than females due to active retirement to the breeding shed.

SPEAKER_00 9:52

Aaron Powell Yeah, exactly. By skipping the fenestration, you really risk missing the underlying intriosseous disease entirely.

SPEAKER_02 10:00

Aaron Powell Right. And uh speaking of the data, there's a pretty fascinating demographic quirk in this cohort. Males were significantly more likely to return to athleticism than females. I think the odds ratio is 4.25.

SPEAKER_00 10:12

It's a huge jump. But the authors are quick to point out this is almost certainly non-medical.

SPEAKER_02 10:16

Aaron Powell Right, because mares with distal hock pain are frequently just retired to the breeding shed rather than push through a lengthy rehab protocol.

SPEAKER_00 10:24

Trevor Burrus Yeah, it's an economic decision, you know, not a physiological one.

SPEAKER_02 10:27

Aaron Powell Makes total sense. So for your next refractory case, DLF ankylosis is a highly reliable, less invasive alternative to traditional open approaches.

SPEAKER_00 10:37

Aaron Powell Absolut. And if the joint space permits needle penetration, incorporating key border bone fenestration is really the definitive move. Aaron Powell Right.

SPEAKER_02 10:45

It secures those athletic outcomes and keeps that horse out of your OR a second time.

SPEAKER_00 10:49

Aaron Powell Which actually brings up a critical blind spot in how these cases are worked up in the field.

SPEAKER_02 10:53

Aaron Powell Well, what's that?

SPEAKER_00 10:55

Well, advanced imaging, like an MRI, is the gold standard for identifying that subchondral bone edema, but it's rarely utilized before a DLF procedure. Trevor Burrus, Jr.

SPEAKER_02 11:04

That's true. You're often going in blind to that deeper pressure.

SPEAKER_00 11:06

Aaron Powell Exactly. It leaves you wondering how many of those failed standard laser treatments, you know, that 20% that bounce back to surgery, are failing simply because the surgeon was clinically blind to that hidden subchondral pressure from the start.

SPEAKER_01 11:24

That's it for this episode of the Semini 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.