Dog Bracing Made Simple

When a dog tears their Cranial Cruciate Ligament (CCL)—the canine equivalent of an ACL tear in humans—owners face a tough decision. Surgery (like a TPLO or Extracapsular Repair) is widely considered the gold standard, but for various reasons—such as financial constraints, high surgical risk, or underlying health issues—many owners turn to custom knee braces (stifle orthoses) as a non-invasive alternative. Custom braces like the Hero Knee Brace promise to support an unstable knee, reduce pain, and restore mobility. On the surface, the standard expectation is that a rigid brace works like a tight clamp, locking down the joint to eliminate all unwanted movement. But biomechanics are rarely that simple. A landmark study titled "Pelvic limb kinematics in the dog with and without a stifle orthosis," authored by Dr. Bryan T. Torres and colleagues (published in Veterinary Surgery), used high-tech motion capture to evaluate joint movement in dogs wearing custom Hero Knee Braces. The data reveal that, while the most surface-level assumptions about bracing seem straightforward, it is actually a set of counterintuitive mechanical design tricks, understood by clinicians, that explain how a brace truly supports an injured knee. Understanding the Goal: Motion Control vs. Motion Elimination To understand how a brace works, it helps to separate what owners expect from how orthoses are actually designed to function: The Common Assumption: A brace should lock the joint in place, preventing movement so the dog can't hurt themselves. The Clinical Reality: A functional stifle brace is supposed to allow normal, active Range of Motion (ROM) so the dog can walk, run, and sit naturally. It shouldn't immobilize the knee. Instead, its job is to step in at one specific moment during the step: mid-stance to stop the “bad motion.”  When a dog puts weight on their leg during mid-stance, the angle of the shinbone (tibia) causes it to slide forward under the thighbone—a painful instability known as cranial thrust or cranial drawer. A successful brace allows normal bending and straightening through most of the step, but selectively limits this harmful sliding motion right at mid-stance. Best Brace Design Parameters [ Active Gait Cycle ] ──► Allows Normal Flexion/Extension (Preserves Function) [ Mid-Stance Phase ]  ──► Restricts Cranial Thrust / Drawer (Targeted Stability) The Surface Conclusion vs. The Counterintuitive Mechanism When evaluating the study data, several key findings challenge basic assumptions and highlight how a stifle brace functions on a deeper level:   1. The Stifle Joint Maintains Active Range of Motion The Surface Takeaway: Looking at the rigid frame of a Hero Knee Brace, one might worry that it will make the dog's leg stiff and uncomfortable. The Counterintuitive Insight: The study demonstrated that the brace barely limits the active Range of Motion at the stifle joint. Walk: Natural knee ROM was 43.1°, while the braced knee maintained 49.1°. Trot: Natural knee ROM was 57.2°, while the braced knee maintained 54.3°. Why this matters: Because soft tissue and skin naturally cushion the brace, the knee moves a bit differently than the brace. How the brace moves isn’t as important as what it causes the body's joints to do differently. Fortunately, the data showed a distinct shift in stifle joint position specifically during the stance phase (when thrust would occur). While this study was conducted on healthy dogs—meaning true cranial drawer wasn't present to measure directly—this specific positional shift at mid-stance strongly suggests that the brace is engaging precisely when it needs to, potentially dampening drawer motion without locking up the knee.  2. How Ankle (Hock) Restriction Actually Protects the Knee The Surface Takeaway: The study found that the lower ankle joint (tarsus/hock) showed reduced movement while wearing the brace. At first glance, restricting a completely healthy adjacent joint seems like an unwanted side effect. The Counterintuitive Insight: Most of the hock’s range of motion is actually preserved, but the mild restriction imposed on the ankle plays a key biomechanical role in protecting the knee. The "Ground Reaction" Effect: By stabilizing and slightly limiting movement at the hock, the orthosis leverages Ground Reaction Force (GRF)—the upward force exerted by the ground when the paw strikes. Instead of letting that energy collapse the ankle, the rigid brace directs that force upward, pushing backward against the front of the proximal tibia.  The Human Connection: This exact principle is used in human medicine through Ground Reaction Ankle-Foot Orthoses (GRAFOs). In humans, a GRAFO uses the floor's force at the ankle to push the tibia back, preventing knee collapse and stabilizing the joint during stance. In dogs, harnessing this same force helps actively counteract forward tibial thrust at the knee. Comparing Joint Motion Dynamics Joint & Plane Unbraced Joint Braced Joint (Limb + Brace) Biomechanical Impact Stifle Flexion/Extension (Walk) 43.1° 49.1° Preserves active motion; shifts stance mechanics to reduce thrust. Stifle Flexion/Extension (Trot) 57.2° 54.3° Maintains a comfortable gait while dampening peak extension. Tarsus/Hock Sagittal ROM (Walk) 33.3° 25.3° Directs ground forces upward to push the tibia back. Tarsus/Hock Frontal ROM (Walk) 14.1° 7.1° Stabilizes side-to-side ankle motion to support knee alignment. What This Means for Dog Owners Understanding these counterintuitive mechanics helps set realistic, evidence-based expectations for custom bracing: Functional Freedom: You don't have to worry about a custom brace like the Hero Knee Brace turning your dog's leg into a rigid post. It allows them to bend, sit, and walk naturally while intervening primarily during the weight-bearing phase of gait. Whole-Leg Engineering: The brace doesn't work on the knee in isolation. By controlling the ankle, it uses basic physics to apply a stabilizing, backward pressure on the shinbone right when weight is applied. Promising Preliminary Evidence: While additional scientific testing on dogs with active CCL tears is needed to explicitly measure drawer reduction, the stance-phase shifts captured in this study offer strong evidence that stifle orthoses provide targeted mechanical support right where it counts. Read the full study here.  

For years, the veterinary community has maintained a cautious—and sometimes skeptical—stance regarding orthotics for managing cranial cruciate ligament (CCL) ruptures. While surgery remains the traditional standard of care, many patients are not ideal candidates due to advanced age, comorbidities, or financial constraints. Custom stifle bracing offers a promising alternative, yet clinical uptake has been hampered by a lingering question: Does wearing a brace cause compensatory mechanical issues or restrict movement elsewhere? At the 11th International Association of Veterinary Rehabilitation and Physical Therapy (IAVRPT) Symposium, Kirsten Häusler presented groundbreaking clinical research that addresses this exact concern head-on. Find full proceedings here The Findings: Preservation of Natural Mechanics Häusler’s study evaluated sound, adult Border Collies walking and trotting on an instrumented treadmill under three distinct conditions: baseline (no brace), while wearing a patient-specific custom stifle brace on the left hindlimb, and immediately post-removal. Using high-precision gait analysis, the study monitored spatial and temporal gait parameters—including symmetry indices, step length, and peak loading across all four limbs. Key insights from the presentation include: No Step Length or Symmetry Deficits: The patient-specific brace provided structural joint support without restricting natural step length or compromising gait symmetry. Zero Adverse Compensatory Load: Crucially, the orthotic produced no negative compensatory shift to the front limbs or contralateral hindlimb. Improved Hindlimb Loading: During trotting, wearing the brace resulted in improved, balanced weight bearing across the hindlimbs. What This Means for the Veterinary Perspective Häusler’s study represents a critical pivot point in how veterinary professionals evaluate non-surgical orthotic options. Historically, critics feared that rigid external bracing might artificially lock down joint mechanics, forcing the dog to alter its stride and overcompensate with healthy limbs. By demonstrating that custom-designed stifle orthotics preserve natural temporospatial gait parameters without inducing mechanical stress elsewhere, Häusler’s work validates orthotics as a safe, biomechanically sound intervention. It lays key objective groundwork showing that a brace can offer stability without forcing detrimental trade-offs. As objective gait analysis continues to replace anecdotal assumptions, research like Häusler’s equips veterinarians and rehabilitation practitioners with the evidence needed to confidently recommend stifle bracing as a primary or supportive therapy for CCL injury management.

***This success story is based on a research project done by Kirsten Hausler, a Veterinary Researcher in Germany.  The original research was published here. A version translated to English can be found here. Dealing with a torn cruciate ligament (often compared to an ACL tear in humans) is a scary moment for any pet parent. While surgery is the most common recommendation, what happens when your dog is older or if general anesthesia is simply too risky? A recent case study by veterinary physical therapy expert Kirsten Hausler highlights an incredible conservative (non-surgical) approach. Through physical therapy and a custom knee brace, a dog who couldn't have surgery was able to walk normally again—and the clinical data proves exactly how it works. Meet Diego Diego is a 9-year-old Bernese Mountain Dog who tore his cruciate ligament while chasing a squirrel. Because of his age and a disastrous past experience with anesthesia, surgery was off the table. His veterinary team decided to try a non-surgical route. The Science of the Limp: How Dogs Shift Their Weight When a dog hurts their knee, they don't just limp—they completely shift their body weight to avoid pain. In a healthy dog, weight is distributed relatively evenly. But when Diego was first injured, researchers used a special high-tech treadmill to measure the exact pressure of his paws. The results showed a massive weight-bearing shift: Diego was putting only 30% of his body weight on his injured back leg, while his healthy back leg was forced to take on 55% of the load. To compensate for his painful hind leg, he also put dangerous strain on his front legs, with his right front paw taking on a whopping 74% load! This severe weight-bearing shift threw his whole body off balance, took a massive amount of energy, and caused a 57.3% asymmetry in his hind legs. The Solution: A GoHeroGo Stifle Brace Diego's treatment started with therapies to reduce swelling, like laser and shock wave treatments, followed by careful underwater treadmill exercises. But the major turning point was fitting him with a custom Goherogo knee orthosis (brace). Getting the brace was a stress-free process for Diego. His vet took a simple mold of his leg in about 20 minutes. That mold was shipped to the USA, and within two weeks, Diego had a custom-made knee brace designed to perfectly fit his leg. Validating the Brace: The Proof is in the Paws How do we actually know the brace is supporting the dog? By measuring those weight-bearing shifts again! Using the instrumented measuring treadmill, the veterinary team was able to capture hard, objective numbers to prove the brace was doing its job: After just three weeks of using the brace, Diego's hind leg asymmetry dropped by more than half, falling to just 10%. After four months, the asymmetry between his back legs dropped to an incredible 2%. The treadmill data showed that the weight load on his injured leg steadily increased over time. Because the brace stabilized the bad knee, Diego felt comfortable bearing weight on it again, which relieved the heavy strain on his other three healthy legs and leveled out his body's center of gravity. By objectively tracking how Diego shifted his weight back to normal, the study validates that the stifle brace actively supports the knee, encourages the dog to use the injured leg, and restores their natural balance. Today, Diego can go on much longer walks and moves safely through his everyday life without pain.

Rising from a torn ACL and multiple surgeries, in the end a simple knee brace allowed Ozzie to return to comfort a Mom battling dementia. Ozzie and Harriet...er... Cecelia and Ozzie have been best friends for the past 11 years. Not only is the 12-year-old, black Chow mix a lifelong companion to Cecelia, but he’s a great comfort to her mom, who has dementia. "Sometimes my mom won't remember who I am, but she'll always recognize her dog,” says Cecelia of her mom’s love of Ozzie. Cecelia moved back home in 1994 to help take care of her ailing mom. Dementia doesn’t just affect one family member — it can take its toll on the whole family. Cecelia says Ozzie has been a great help, with his calming and steadying presence, for all members of her family. Cecelia found Ozzie back in 2004 on a pet-finding website. She drove from just outside of Lincoln, Nebraska all the way to St. Louis, Missouri that Memorial Day weekend. Ozzie was only about 1 1/2 years old then. Adventure takes a turn Besides having a therapeutic nature, Ozzie also has an adventurous spirit. On a recent visit to a friend’s house, Ozzie injured his leg playing sand volleyball with the other dogs. When he was trying to get back in the car after the visit, Ozzie whimpered. While it occurred to Cecelia that it could be hip dysplasia, it turned out that Ozzie had actually torn the ligament in his knee. Ozzie's veterinarian recommended surgery. Unfortunately, the first surgery was not successful. As a result, a second surgery was performed. But Ozzie wasn’t out of the woods yet. While he was recovering from his second surgery, he tore the ligament in his other knee. Ozzie then underwent a third surgery to help repair the ligament in that knee. Cecelia knew she had to do something to help Ozzie. After three surgeries, she had to find some additional support to help him heal properly and avoid further injury. She thought about what is available to humans for similar injuries. Humans often use leg braces. Was something like this an option for dogs? The knee brace After some research, she discovered Hero and its dog leg braces. After Cecelia connected Ozzie's veterinarian, Dr. Pat McInteer at Hillcrest Animal Clinic, with Hero Braces, the company sent a casting kit. Within a few weeks, Ozzie's brace arrived at the door. After the brace was placed on Ozzie, he was able to stand up and bear weight on his leg immediately. Within a few hours, Ozzie was almost back to walking normally. Ozzie is getting up there in years — but don't tell him that — and he is undergoing treatment for arthritis of his toes. He doesn't run as much as he used to, but he is able to go for short strolls and live pain-free. He continues providing companionship and therapy to Cecelia and her mom. While Cecelia does all she can to help the dog that has given her family so much to live a full, happy life. (Ozzie’s story was originally posted on June 12, 2015.)

Bodhi is a survivor. She's a 14-year-old, lovable Cattledog and has been battling cancer for the last year and a half. She's been through two surgeries and two rounds of chemo, but nothing can keep her down. Literally. A few months ago, Bodhi was playing in the backyard when she made a quick turn and immediately yelped, falling to the ground in pain. Doctors determined that she had completely torn her back left ACL. She was unable to put any weight on it at all, with all movement excruciating. Bodhi need to be carried around everywhere, even outside to relieve herself. This was another obstacle to a dog who has already gone through so much. Because of Bodhi's cancer and her age, her oncologist recommended against surgery since it would require months of rehab. Out of options, the family considered putting Bodhi down. Then her chiropractor suggested a Hero Brace as an option. She had seen success for other clients and referred the family to Dr. Annette Richmond in Carmel, CA. Dr. Richmond examined Bodhi and created the cast for the brace. After three weeks, the brace for the ACL tear arrived. It only took a day or so for Bodhi to get used to the brace. Now she wears the brace from morning until just before bedtime and has about 80% of her mobility back. Bill, Bodhi's owner, reports that her attitude improved immediately, and her quality of life has returned. "Shortly after she started wearing her Hero Brace, she got her "silly" back and is thoroughly enjoying her golden years," Bill says. "I just wanted to say thank you for such a great product. I can't speak highly enough of the results."Bohdi has overcome so much in her dog life. We are happy to be a part of her survivor story. Go. Bohdi. Go

When Alisha says "hold the pickles," she's not talking about a burger. She's talking about her almost three-year-old Great Pyrenees/Akbash-mix Pickles. Alisha has been holding and snuggling Pickles since the rescue dog was six weeks old. Pickles had been battling a severe case of parvovirus and struggled with respiratory issues for months with a less than 50% chance of survival. After fighting back with a mix of medications, steroids and a whole lot of moxie, Pickles pulled through. Just this spring, Pickles was playing with her sister Popcorn (I know. Adorable.) when she made a quick turn on the wet grass and let out a yelp. Alisha's father-in-law, a veterinarian, knew immediately that Pickles had torn a ligament. The family's local vet recommended surgery, but Alisha was apprehensive. She was concerned about complications with the hardware required for the recommended surgery. She was worried about future injury after the surgery. She was also apprehensive about the 6 months recovery time and wondered how Pickles would be able to remain immobile with three other active dogs in the house. Alisha decided to look for other options. Alisha's husband had torn his ACL a few years earlier (a similar injury to a dog's CCL tear). One of the options his doctor had recommended had been a non-surgical route with bracing. Alisha knew that if that was an option for humans, there would have to be something similar for dogs. That is when she found Hero Braces. "The durability and the science behind the brace is pretty impeccable. Now Pickles and her dad have matching braces; it's crazy how much the braces function and resemble one another." Since Pickles has received her ACL brace, the family is amazed at how active she has become again. She runs and is able to keep up with her pack. When Pickles is in her brace, she acts like a puppy again. Alisha says that Pickles gets excited to put it on and has never shown any discomfort, "We call her our little bionic pup." Bionic Pickles. Sounds like a great superhero name to us.

If you ever wondered where stifle bracing started, Dr. Adrian was there from the beginning.  She has played an integral roll in the evolution of several braces and has worked with most manufactures helping dogs. Devoting her professional career to helping further canine physical therapy, she was the first person to earn a PhD in canine biomechanics from CSU Veterinary School. Below is an interview from dvm360 about her experiences with cruciate bracing. Dr. Adrian started working with Hero Braces in 2005 and has help us refine our brace designs to help thousands of dogs.  We appreciate her insight very much! Owners appreciate veterinarians that offer bracing for the dogs that cannot have surgery.

Yearning to return hiking and his camping lifestyle, Jason Darrah of the Primal Outdoors Channel needed to find a way to help his dog Wheeler avoid surgery for his torn ACL. Looking for an alternative to surgery he found Dr. Lisa Plumb of Klamath Animal Hospital and Go Hero Braces. Watch his journey below: And if you are really in the mood, buy some of Wheeler's coffee here!

Not sure bracing fits into your practice? Initially a skeptic, Dr. Beck shares how her veterinary practice has grown to use bracing. 100% of my professional time is devoted to healing animals.  You could say I come by it naturally.  My father and I are both veterinarians. I took it a step further and am a certified canine rehabilitation therapist. Our private practice still believes surgery, with rehab, is the best way to treat orthopedic injuries. AND not all dogs can have surgery. My first experiences withe bracing were in 2010.  Initially, I was skeptical about bracing for cranial cruciate disease (torn ACL). After bracing many patients I have found it extremely useful when used in combination with rehabilitation therapies. I have had many cases where bracing has made a dramatic difference in a pets life. One patient tore both CCLs in the course of two years and chose to brace one leg and rest for the other (conservative management).  While both knees are now stable, the braced knee has better range of motion and less scar tissue that the knee that went unstabilized (no surgery, no brace).  I think that speaks to the biomechanics of the brace in preventing tibial thrust. I had a 150 lb. Boerboel dog tear both cruciates within 30 minutes of each other.  He had surgery on one knee and the other knee was braced. Otherwise he would not be able to walk and he was certainly to large for his mom to carry. I had a labrador retriever patient that lived on the second story apartment building with no elevator.  Bracing allowed her to use the stairs without pain, and she could still go for walks with her mom in downtown Omaha..  This treatment certainly made life easier for her mom! The Brace Honestly, I think what makes Hero Braces exceptional is their customer service. I feel like Ben, the orthotist, has a deeper understanding of the needed fit and support because he is an amputee and wears a prosthesis everyday. I have always believed that the more empathy you can have for your patients, the higher quality care you can provide them. The Hero Braces are very high quality and durable for all the wear and tear a dog can do. Dogs do very well with the application of the braces, and most owners do a great job monitoring the leg for  any changes from the brace. Michelle Beck, DVM CCRT

Super excited about the research coming out on the Hero Brace. Torn Dog ACL? The Groundbreaking Science Behind Why the Right Knee Brace Actually Works If you’ve just found out your dog has a torn CCL (Cranial Cruciate Ligament), which is basically the doggie equivalent of a human ACL tear, your mind is probably racing. Your vet might have told you that expensive surgery is the only real option. But what if your dog is too old for anesthesia? What if they have other medical conditions, or what if surgery simply isn’t in your budget right now? For a long time, the veterinary world looked down on knee braces, writing them off as useless band-aids. But a fascinating episode of The Veterinary Rehabilitation Podcast turned that assumption upside down. Host Megan Kelly sat down with Ben Blecha (a human and animal brace expert and founder of Hero Braces) and Dr. Kiki Haeusler (a leading German veterinary physical therapist and researcher). They discussed brand-new, hard scientific data that proves a properly engineered, custom rigid brace isn't just a backup plan, it actively stabilizes your dog's knee and helps them heal. Here is what the latest science says, and why it perfectly explains why the Hero Brace design works so well. The Big Problem: Why Vets Used to Hate Braces To understand why this new research is such a big deal, we have to look at why vets were skeptical in the first place. If you go online right now, you can find dozens of cheap, soft neoprene fabric sleeves claiming to cure dog knee injuries. Spoiler alert: they don’t. When a dog tears their CCL, their knee joint becomes completely unstable. Every time they step down, their shin bone (tibia) slides forward painfully against their thigh bone (femur). A soft fabric sleeve cannot stop that massive mechanical shifting. Vets saw these cheap braces failing and causing nasty skin sores, so they assumed all braces were bad. But human medicine moved away from soft knee wraps decades ago, opting instead for custom-molded, hard-shell braces. The podcast panel set out to prove that when you apply that same advanced human engineering to dogs, the results are magical. The Science: The Treadmill That Doesn’t Lie Dr. Kiki Haeusler wanted to take the guesswork out of the equation. Instead of just asking owners, "Does your dog seem better?" (which can be biased), she put injured dogs on a highly advanced, high-tech piece of equipment called the Zebris CanidGait system. Think of it as a super-smart treadmill packed with thousands of pressure sensors. It measures: Exactly how many pounds of pressure the dog puts on each individual paw. The exact length and rhythm of their stride. How much they are limping or shifting their weight to their healthy legs. By testing CCL-deficient dogs completely bare-legged, and then testing them again wearing a custom rigid brace, Dr. Haeusler got undeniable, mathematical proof: The right brace instantly improves the dog's gait, balances their weight distribution, and stops the limp. Why the Research Points Directly to the "Hero Brace" Design The most exciting part of the discussion was how Dr. Haeusler’s data perfectly validated the exact engineering behind the Hero Brace. The data showed that for a brace to actually work, it needs to follow a very specific design checklist. Here is how the Hero Brace delivers on that science: 1. It Must Be Hard and Custom-Molded (No Soft Fabrics!) Dr. Haeusler's research proved that only a rigid structure can fight the forces inside a dog's knee. The Hero Brace is made from an ultra-durable, medical-grade rigid plastic shell. Because it is built from a custom plaster cast of your exact dog's leg, it fits like a second skin. It doesn't twist, slip, or rub, which completely eliminates the skin sores caused by generic braces. 2. The Magical "Three-Point Pressure" System To stop the shin bone from sliding forward painfully, a brace has to push back in just the right places. Ben Blecha explained the "Three-Point" physics system built into the Hero Brace: Point 1: A firm hold on the back of the thigh. Point 2: A secure anchor point low on the ankle. Point 3: A crucial, protective pad on the front of the shin that gently pushes the shin bone backward into its proper place. When your dog steps down, this three-point system acts as an external ligament, locking the joint in place so they can walk without pain. 3. An Hinge That Mimics Nature A dog’s knee doesn't just open and close like a simple door hinge; it moves in a complex, rolling arc. If a brace hinge is placed incorrectly, it will fight against your dog's leg, causing pain. Hero Braces use aircraft-grade aluminum hinges that are aligned perfectly with your dog's natural joint center. Dr. Haeusler's data showed that this allows the dog to flex and extend their leg totally naturally while completely blocking the dangerous sideways and forward sliding. 4. Boosting Your Dog's "Brain-Body" Connection When a dog tears their ligament, they lose the nerve endings that tell their brain where their leg is in space. This makes them protective, fearful, and hesitant to use the leg, leading to rapid muscle loss. Dr. Haeusler noticed that dogs wearing a total-contact rigid brace immediately walked with more confidence. The gentle, snug fit of the Hero Brace stimulates the nerves in the skin and muscles, essentially sending a message to the brain saying: "Don't worry, your knee is safe. You can step down now." Key Takeaway: A custom rigid brace doesn't just protect the knee mechanically; it gives your dog the psychological confidence to use their leg again, preventing their muscles from wasting away. The Road to Recovery: What This Means For Your Dog So, what happens long-term? When a dog wears a Hero Brace, the joint is held completely still and steady. Over a period of several months, your dog’s body does something amazing: it builds up its own natural scar tissue (fibrosis) around the joint. This scar tissue acts as a permanent, internal brace. Furthermore, because the treadmill data proves dogs can safely bear weight while wearing the brace, you can start physical therapy much sooner! You can safely take your braced dog to underwater treadmill sessions, do gentle balance exercises, and go for controlled walks. Best of all? By supporting the injured leg, you prevent your dog from overloading their other back leg, ”saving them from the dreaded "second ACL tear" that happens to so many dogs. The Bottom Line If surgery isn't the right path for your family, you don't have to lose hope. The science has officially caught up to the technology. By combining Dr. Haeusler’s groundbreaking data with Hero Braces’ custom human-grade engineering, we now know that conservative management with a rigid orthosis is a highly effective, scientifically backed way to get your best friend back on their paws. Special thanks to Dr. Kelly at Online Pet Health for the interview on the research presented by Kiki Haeusler at the IAVRPT at the University of Cambridge in August of 2022.

Dr. Adrian (PhD in Canine Biomechanics) breaks down why custom bracing works. See her expert endorsement of Hero Braces for dogs that cannot undergo CCL surgery.