TPLO recovery · Dog health

12 Things Nobody Tells You About The Other Knee After TPLO

If your dog already had one knee surgery, #5 is the one to check tonight.

The Recovery Desk · Updated October 2026 · 6 min read

You did everything right the first time. The surgery, the crate rest, the sling walks, the twelve weeks of "not yet, buddy."

Then one day you notice the other back leg doing something it didn't do before.

Here's what most owners only find out after the second bill.

1.The first tear usually wasn't an accident

Most owners remember the moment. A leap off the couch. A hard turn after a ball. A bad step on the ice.

But in most big dogs, the ligament didn't snap because of that one step. It had been wearing down for months, fiber by fiber, and that step was just the last one.

That matters for one reason: whatever wore down the first ligament didn't leave with the surgery.

2.Same dog, same weight, same genes. It's in both knees.

When researchers looked inside the knees of dogs that had torn only one ligament, they found early arthritis changes in both knees. Every single dog they checked. Including the knee that looked perfectly fine.

Inside every knee there's a thin lining that keeps the joint fed. In a lot of big dogs, that lining stays quietly inflamed for months. No limp, no yelp. And that inflammation is what slowly wears the ligament out.

We call it Mirror Knee Syndrome: the same slow wear, happening in the knee nobody operated on.

Think of brake pads. When one side wears down to metal, you replace both. The other side rode the same rotor for the same miles.

3.The number surgeons quote for the other knee

Ask most orthopedic surgeons and you'll hear a number somewhere between 40 and 60 percent. That's how many dogs who tear one cruciate ligament go on to tear the other one.

For some dogs it happens a few months after the first surgery. For others it's two or three years later.

And when it does, a lot of owners find out the hard way that their insurance calls the second knee "pre-existing." The second TPLO usually costs what the first one did: $4,000 to $8,000, sometimes more.

4.The good leg has been doing double duty since surgery day

For weeks after TPLO, the operated leg barely touches the ground. Watch a dog in recovery stand still and you'll see it: almost all the weight on the other back leg.

That's normal. It's also months of extra load on a knee that, per #2, may already be wearing the same way.

Owners spend recovery focused on the scar. Meanwhile the knee with no scar is carrying the dog.

5.The signs owners miss

These are easy to brush off as "he's just getting older." Look at the leg without the scar:

• The sit. The back leg slides out to the side instead of tucking in square.
• The pause. A beat before getting up, especially after a nap or first thing in the morning.
• The check. He looks at the step (the couch, the car, the stairs) before he commits.
• Shorter walks. Turning back early, or sitting down halfway.
• The weight shift. Standing still with that foot barely touching, or shifting side to side.
• The thing he stopped doing. The jump onto the bed. Running to the door.

None of these is a diagnosis. But if you see two or more on the good leg, mention it at your next vet visit, and keep reading.

6.Keeping him lean helps. It doesn't touch the knee lining.

Do all of it. Keep him lean. Rugs on the slick floors. A ramp for the truck. No more ball launcher on hard turns.

Every pound and every jump you take off that knee matters.

But none of it reaches the inflamed lining inside the joint. A lean dog on a ramp can still have a knee that's quietly wearing down.

7.Pain meds quiet the soreness, not the strain

Meds have their place, and your vet will tell you when your dog needs them.

But they ease how the knee feels. They don't take any weight off the good leg. And a dog who suddenly feels great tends to go right back to jumping on it.

Most vets also want regular bloodwork for long-term use, and a lot of owners don't want their dog on daily meds for years.

8.Rehab laser works. But it stops when the appointments stop.

If your dog did formal rehab after TPLO, there's a good chance it included laser sessions: red and near-infrared light aimed at the joint.

It's one of the most common tools in canine rehab. It's also $30 to $75 a session, plus the drive, plus lifting a big dog in and out of the car.

So most dogs get a handful of sessions during recovery, and then it ends. Right about when the other knee is doing the most work.

That gap is why we built MedaRed™ Infrared: the same kind of red and near-infrared light from the rehab clinic, made to use at home, every night, without the appointment.

9.Kilde One™: both back knees, 10 minutes a night, at home

Kilde One™ is two soft wraps, one for each back knee. Each one puts MedaRed™ Infrared flat against the skin, under the coat, right where the knee is.

You put them on while he's already lying down. Ten minutes on the couch next to you. Then they switch themselves off.

• Both back knees at once: the one they fixed and the one doing double duty
• Every night, not once a week: the routine rehab can't give you
• For comfort, stiffness and easier get-ups, alongside whatever your vet has him on

It doesn't replace your surgeon. It gives the knee nobody operated on something every single night.

100-night money-back guarantee · Free shipping on bundles

10.Built for real life with a big dog

• Cordless. Rechargeable, so it works on the couch, in the crate or inside a recovery pen.
• Two velcro straps. On in seconds, no wrestling.
• Switches itself off after 10 minutes. No timer to remember.
• Soft on shaved or sensitive skin.
• Starting on the operated knee? Ask your surgeon first. Most owners start on the other knee right away and add the repaired knee once the incision is fully healed. Never use it over an open or healing incision.

11.What owners watch for in the first few weeks

You won't see it overnight. What owners watch for:

• Getting up without that pause
• Sitting square again
• Taking the step up without checking the leg first
• Walks that go back to their old length

12.The two things TPLO owners end up needing anyway

The back knees are covered. But in almost every TPLO house, two more problems show up within a few weeks. Here's what they are, and why the full set costs less than buying your way into them later.

1. The stairs, the car and the 2 a.m. potty trip

For weeks after surgery he can't do steps or jump into the car on his own. So most owners end up hoisting a 70 to 100 lb dog by the back end with a bath towel.

Every one of those lifts puts his weight right back on the knees you're trying to protect. And on your back.

The Kilde Lift Harness has a handle right over his hips. You carry the load on every step, every car ride and every trip outside, so neither back knee has to. Your discharge sheet probably told you to support his back end with a towel or a sling. This is the version of that towel built for a 100 lb dog.

2. The front legs pick up what the back legs can't

When the back knees are sore, dogs shift their weight forward. Watch him stand up from a nap: he pulls with the front end and drags the back.

That means his front legs are now carrying load they were never built to carry, every day, for months.

The front-leg wraps (blue tab) put the same MedaRed™ light on the legs that are doing the work now. Otherwise you're taking care of the back end while the front end quietly wears down next.

And every set is covered by the same 100-night money-back guarantee. If his knees don't thank you, you get every dollar back. So the full set is the lowest-risk way to try it.

Pick the set that fits your dog:

BEST VALUE · ALL 4 LEGS

Complete Longevity Bundle

2 back-knee wraps + 2 front-leg wraps · 2 chargers · Lift Harness FREE · free shipping

$179.95$279.85

MOST POPULAR

Knee Recovery Set

2 knee wraps · charger · Kilde Lift Harness $50 off · free shipping

$139.95$189.90

Starter Kit

2 knee wraps · charger · back knees only

$89.95$129.95

Every set includes the free Other Knee guide: the early signs, a 60-second couch check, and room-by-room home setup.

Limited-time pricing. Stock on the bundles is low.