She’s 17 years old and going home tomorrow. Today we are working with Social Service and Case Management to get all the equipment she and her family will need for her ongoing care – dressing supplies, a walker, crutches, a wheelchair and a raised commode seat.
She’s 17 years old and three weeks ago I amputated her right leg above the knee. Before that operation she went through six surgeries to try to salvage the leg.
She’s just an ordinary kid. Not a star athlete, not a great student. She likes horses and Harry Potter and boating with family and friends on Lake Saguaro. She wonders if she’ll be able to graduate from high school this year, if she’ll ever be able to swim again, if she will be able to work as a hairdresser, which was her goal after graduation.
It was a weekend night full of fun and a few really bad decisions. Underage drinking, driving too fast on the 101 and a fight with her boyfriend all played a part. I wasn’t on when she came in, but was involved in her care as the rounding surgeon for the trauma service off and on for the whole six weeks she was in the hospital.
Her right leg got caught on something under the dashboard when the car rolled. Her boyfriend, who was driving, was ejected and died at the scene. Her right knee was dislocated posteriorly and the tibia and fibula, the two bones of the lower leg were shattered. Most of the skin on the lower part of her leg was degloved, ripped off of the underlying muscle. There was serious talk between the orthopedic surgeon and the trauma surgeon of completing the amputation that night. But she was 17 years old and healthy. Instead they went to surgery and did what they could.
Posterior knee dislocations are particularly devastating injuries because of the high incidence of injury to the popliteal artery. It’s the blood supply to everything below the knee and is runs through a narrow space right behind the lower end of the femur and upper end of the tibia. It’s relatively fixed in place by the big muscle groups around the joint and so when the tibia moves backwards in a posterior dislocation it can shear the vessel in two just like a guillotine.
The first goal in a vascular injury like this is to stabilize the bones. The leg will tolerate up to four hours of warm ischemia time, longer if the tissue is chilled, but vascular repairs are sensitive and don’t tolerate twisting, kinking or tension. If the bones aren’t secured, any repair will fail.
Popliteal arteries are hard to get at. Direct repair is rarely possible. More commonly a piece of vein is harvested and used to jump across the damaged segment from good vessel above to good vessel below.
In this case, there wasn’t much good vessel above or below. The artery hadn’t been sheared cleanly but rather had been stretched until it ripped. That caused unseen damage to the intima, the lining of the vessel, for a considerable distance above the visible tear. The degloving had also disrupted the vessels below the knee so there wasn’t much to jump a graft to down there.
The orthopedic surgeon put on an external fixator, an erector set like device of rods and pins that screw into the bone and attach to a lightweight external frame that keeps the bone from moving. The vascular surgeon did a vein graft and the trauma surgeon pulled what skin he could over the open wound. A vacuum dressing completed the first procedure.
I saw her on ICU rounds a few hours later and knew she was in trouble. Her blood was still acidotic, too much lactic acid in circulation, a sign of tissue that wasn’t getting enough oxygen. There was no detectable pulse below the knee and her toes were purple. The vascular surgeon took her back to surgery an hour later, and again six hours after that. And again. And again. All the time moving his graft to different tiny vessels in the lower leg looking for one that would support enough flow to nourish the muscles. One by one they shut down and the muscles died. After 18 days in the ICU on multiple antibiotics, sodium bicarbonate to correct the acidosis and heparin to keep the vessels from clotting off, we had the difficult conversation with her and her family.
She’s going home tomorrow.