Cut to the Bone

Wendy Baltzer's surgical technique does the trick for an old dog
In OSU's Lois Bates Acheson Veterinary Teaching Hospital, veterinary surgeon Wendy Baltzer repairs a ligament injury for an aging Chow mix using state-of-the-art arthroscopic instruments.

In OSU's Lois Bates Acheson Veterinary Teaching Hospital, veterinary surgeon Wendy Baltzer repairs a ligament injury for an aging Chow mix using state-of-the-art arthroscopic instruments. (Photo: Jill Bartlett)

The surgical suite in OSU’s small animal clinic bristles with crisp efficiency. A masked med tech wearing scrubs of sea-foam green unpacks sterile instruments from stainless-steel carts, treading lightly on puffy blue booties. Above the operating table, a state-of-the-art Stryker scope hangs like a giant jointed bug with shiny hooded eyes. The scene suggests an episode of “ER” – until the patient is wheeled in.

Patient No. 504-775 is a medium-sized, black-and-white canine, flat on his back, a pincushion of IV needles and plastic tubes. His head hangs limply, ears in a reverse flop. Three legs splay wildly, the fourth shaved bare and suspended vertically. Chewy! My graying old Chow mix, his injured leg naked and pink, looks unbearably vulnerable. My heart constricts with love.

I’m sitting just outside the Chang Surgical Suite, nearly pressing my nose to the viewing window while the team expertly preps my dog for arthroscopic surgery. The lump in my throat doesn’t stop me from smiling at the incongruity of it all: The mongrel I rescued from the pound 13 years ago for $35 is undergoing a $3,000 treatment at the Lois Bates Acheson Veterinary Teaching Hospital, whose $300,000 scope would be the envy of many human hospitals. The sight of my overweight mutt sprouting IV tubes, his vital signs blipping across a video screen as a nurse swabs disinfectant on his leg, is both poignant and droll.

While Chewy’s pedigree is not pure, his zest for life is. Unbridled exuberance is often his undoing. He has been bested by a porcupine (100 quills in the snout), humiliated by a pair of Rottweilers (a nasty bite on the flank), and scolded by me (too many times to count) for gleefully chasing my cat whenever he thinks he can get away with it. In December, he tore his knee running after a deer on our wooded hillside, yelping and sinking to the ground in pain. In doing so, he joined the 1 million other American dogs that go under the scalpel each year with a rupture of the cranial cruciate ligament, a tough, fibrous tissue that holds the leg bones in place. The annual cost to pet owners: $1.3 billion, according to a 2005 article in the Journal of the American Veterinary Medical Association.

That’s where Wendy Baltzer comes in. As one of a handful of Oregon doctors specializing in canine knee repairs, the assistant professor in OSU’s College of Veterinary Medicine performs eight to 10 cruciate ligament surgeries a month. Sixty-pound Chewy, who was referred to OSU by his regular vet in Corvallis, is a mid-sized patient for Baltzer, who has operated on miniatures weighing barely 2 pounds all the way up to mastiffs and Great Pyrenees tipping the scale at 230. “No other species has such a wide size disparity as the dog,” she says. “But on the inside, they’re all the same.”

Seeing Within

 Veterinary students Elizabeth James (left) from Roseburg, Oregon, and Sara Neilson of Salt Lake City, Utah, prep Chewy for his surgery .

Veterinary students Elizabeth James (left) from Roseburg, Oregon, and Sara Neilson of Salt Lake City, Utah, prep Chewy for his surgery. (Photo: Jill Bartlett)

Even to a casual observer, Baltzer’s command of the scene is clear. The 40-year-old surgeon, noticeably pregnant under her scrubs, strides into the operating theater with a calm certitude gained from 15 years of teaching, research and clinical practice, the past three at OSU. Growing up on a California ranch where animals were as integral to her world as oxygen, she also happened to live next-door to a veterinarian. Add to that her love of science, and a career caring for domestic species was almost preordained.

On this December morning as Chewy lies unconscious, she confers with her team (a resident, an intern, two fourth-year students, an anesthesiologist, a nurse anesthetist and a surgery technician) and then examines the instruments gleaming on a cloth of periwinkle blue: the to-be-expected needles, syringes and scalpels alongside more industrial-type tools – screws, hammers, chisels, drills. I try to push away the thought that they look uncomfortably like medieval torture devices.

Baltzer is about to perform a two-part procedure while the students observe and sometimes assist: arthroscopic removal of Chewy’s torn tissue followed by a “tibia plateau-leveling osteotomy” to alter the angle at which his two large leg bones – the tibia and femur – meet at the knee. (See illustrations in Terra UpClose sidebar)

This technique, invented by late Eugene veterinarian Barclay Slocum, makes the ropelike cruciate unnecessary. Trying to fix the ligament with tissue from a cadaver, as doctors typically do in humans, means months of downtime.

“It takes a year for them to recover,” Baltzer explains. “With humans, you can control their activity a lot more closely. But for 
my patients, I need something that’s a lot more stable much more quickly. With this technique, there’s much less chance of failure.”

As Chewy lies supine and inert, a breathing tube protruding between his teeth, Baltzer cuts two tiny incisions (she calls them “portals”) in his knee. Through one portal she inserts the scope – a fiberoptic camera about the size of a breath mint – which is linked to a television monitor. Through the other she guides a tiny instrument called a shaver. Then, watching the magnified image of Chewy’s torn tissue on the overhead screen – a glowing kaleidoscope in shades of scarlet, pink and magenta – she manipulates the tools with her small, gloved hands, adeptly cutting away the ragged remnants of the painful rupture that had forced Chewy to totter around on three legs. The shaver sucks up the frayed tissue as it cuts.

“Learning to triangulate – to figure out where you are inside the joint while watching the monitor – is kind of like playing video games,” says Baltzer, who teaches courses in principles of surgery, small-animal surgery and small-animal medicine. “It takes two or three years to master.”

Cadavers and Spleens

 Chewy received a "tibia plateau-leveling osteotomy" after tearing his cruciate ligament. The technique changes the biomechanics of the animal's leg.

Chewy received a "tibia plateau-leveling osteotomy" after tearing his cruciate ligament. The technique changes the biomechanics of the animal's leg. (Photo: Jill Bartlett)

Baltzer honed the delicate art of arthroscopic surgery as a resident at Texas A&M University. “To be a surgeon, you have to be kinesthetic,” she says. “When I was a third-year vet student practicing surgery on a cadaver dog, I was the first person in the class to get the spleen out. I loved it! My professor came to me and said, ‘You should do surgery.’”

In those days, minimally invasive surgery was an emerging field. Not until last year did it become coursework required by the American College of Veterinary Surgeons.

The scope Baltzer is using on Chewy, which international medical equipment manufacturer Stryker provided to the teaching hospital for about half-price, makes OSU uniquely positioned in the state. “As far as I know,” Baltzer says, “we’re the only referral practice in Oregon that does arthroscopy on all knees. Because we’re a teaching institution, we try to do everything state-of-the-art. It’s more time-consuming than traditional surgery, and it’s less profitable because of the equipment cost. But research has shown that arthroscopy has a much quicker healing period. The patient is walking on the leg a lot sooner, and they’re much more comfortable postoperatively.”

After the damaged ligament and meniscus (a pillow-like disc that cushions the joint) are gone, Baltzer opens the leg for Step Two of the procedure. I had been lulled by the relatively bloodless arthroscopy, so I’m jolted by how fast the wads of gauze being packed around Chewy’s exposed bone are soaked in blood. I wince at the electric drill’s high-pitched whirrrrr as the doctor slices into the bone. Trying to quiet my nerves, I take note of Chewy’s chest rising and falling, rising and falling. I scrutinize the anesthesiologist, whose eyes are fixed on the rainbow of electronic signals flowing rhythmically across a computer screen to monitor blood pressure, heart rate and oxygen levels. Everything’s OK. I will myself to take a deep breath.

The last step before closing the incision is to affix a stainless steel plate over the cut bone. Drilling holes in bone isn’t all that different, Baltzer asserts, from drilling into wood for the carpentry projects she does at home with her husband, Craig Ruaux, an assistant professor in internal medicine at OSU. Using a depth gauge, she judges which size of surgical-grade screws are needed to secure Chewy’s new leg plate.

Tail End

 Writer and dog owner Lee Sherman takes notes outside the Chang Surgical Suite as the surgical team removes Chewy's torn tissue arthroscopically.

Writer and dog owner Lee Sherman takes notes outside the Chang Surgical Suite as the surgical team removes Chewy's torn tissue arthroscopically. (Photo: Jill Bartlett)

When the last bit of hardware is in place, the surgeon catches my eye through the viewing window. “Wait there,” she mouths. A minute later, she rounds the corner and walks down the hall toward me, shaking loose her hair from the blue bonnet.

“It went great,” she assures me. “Now there’s nothing left but the suturing. Chewy will be fine – he just won’t be able to run around 
like a maniac.”

As she heads out to do rounds with students assigned to clinical rotation, I look back at the OR where the resident is closing the skin over the plate glinting in Chewy’s leg. The suite’s crisp sterility has been marred by wastebaskets overflowing with stained towels and bloody gauze. I think about how far Chewy’s leg has carried him, the hundreds of miles of beach sand, forest trail, park lawn and city sidewalk we’ve trekked together, his nose scenting the way.

Proving Ground for Veterinary Practice

OSU’s small-animal clinic and hospital is a leader in minimally invasive surgery, therapeutic laser research, and treatments for cancer and cardiovascular disease.

Read more…

With his meniscus gone he’ll get arthritis eventually, Baltzer says. And his days of table scraps are over: Per doctor’s orders, he’ll come home to a strict diet. Losing his excess weight will help prevent a rupture 
on his other knee.

This plain dog – who a friend once noted is “always smiling” – has been given another chance to romp and snuffle and snuggle and grin. As for me, I’ve been granted more time with the four-legged pal of unknown lineage who can melt my heart with a simple wag of his tail.

To support the OSU College of Veterinary Medicine, contact the OSU Foundation

Comments are closed.