Leg Reversed and Reattached

When Dugan Smith, an active fourth-grader fell and broke his femur, he and his parents found he had a bigger problem than a broken leg. Just above Dugan’s knee lay a softball-sized malignant tumor.

His doctor, Joel Mayerson, M.D., Associate Professor of Orthopedic Surgery and Director of the Ohio State University’s (OSU) Division of Musculoskeletal Oncology and Director of OSU’s, Orthopaedic Residency Program, reduced Dugan’s fracture, put him in a cast and started four months of chemotherapy. But that was just the beginning.

“For a ten-year-old child like Dugan with osteosarcoma we were facing essentially four treatment options. We could remove the tumor and fill the void with allograft or we could replace the distal femur with prosthesis or we could amputate above the knee or, finally, we could do a procedure called rotationplasty” recalls Dr. Mayerson.

“We discussed the options with Dugan’s parents, we conducted a psychology evaluation of Dugan, we talked about the cosmetics and functional aspects of each option but probably the most important consideration for Dugan was his activity level both now and in the future. Dugan told us that he wanted to be able to play baseball. After reviewing the options, Dugan’s parents actually let him make the final decision. He said to me ‘Doc, do whatever you have to do to get me back to playing baseball.'"

Rotationplasty

Rotationplasty is a rare procedure in the United States and more commonly performed in Holland where Dr. C.P. Van Ness introduced the surgery in 1950 for children with congenital limb differences. Surgeons who are familiar with the procedure choose it over other approaches when mobility is a primary consideration.

Rotationplasty is where the foot is attached to where the knee joint used to be. The foot’s heel is in front and the toes are pointing back—rotated in other words. In this new position, the ankle joint now functions in place of the knee joint. Surprisingly to people who are unfamiliar with the approach, the ankle joint will, over time, create a functional, natural knee and the toes actually provide a vital sensory feedback to the brain.

Long-Term Results

Several studies have reviewed the long-term results of rotationplasty on skeletally immature patients. One published in the journal Clinical Orthopedics and Related Research, author Hanlon M. Krajbich reviewed the cases of 21 skeletally immature patients with a Grade IIB osteosarcoma about the knee who’d been treated with a modified Van Ness rotationplasty. Fourteen patients were followed up for 4 to 10.5 years (mean follow-up, 8 years). Functional assessment using Enneking's method showed all had good or excellent results. No patient thought that the reconstruction affected their ability to achieve recreational, sporting, or career goals. The reconstruction is durable and is not associated with an increase in late complications.

Another study published in the same journal in June 2007 by authors Agarwal, et al., offered a more detailed review of rotationplasty. These authors evaluated the disease status and functional results in 30 patients (range, 6-25 years) who underwent rotationplasty for bone sarcomas from January 2000 to February 2004. The surgeons in these cases used plating in all 27 distal femur resections. In the proximal femur tumor, the surgeons contoured the distal femur and fixed it to the ilium with cancellous screws. In two cases which involved the entire femur, the surgeons articulated the upper end of the tibia with the acetabulum in one case and inserted an Austin Moore prosthesis in the upper end of the tibia in the other.

According to Agarwal, et al., two patients underwent an amputation after postoperative vascular compromise. The authors also noted that two patients had venous congestion complications but they both recovered after exploration. The authors also reported that one patient experienced partially recovered nerve palsy. Two patients had wound infection. One patient had a nonunion which was treated with subsequent bone grafting. The authors were able to follow up and document outcomes in 26 of the 30 patients in the study. Follow-up periods ranged from 24 to 60 months. Finally, the authors used the Musculoskeletal Tumor Society scoring system.

Agarwal, et al., found that 20 of the 26 patients who’d been treated with rotationplasty and had been evaluated for the study had a follow-up score of 25 or greater. The authors conclusions? “Rotationplasty provides good local disease control and good function for young patients with a primary bone sarcoma.”

Cosmetics

Dugan at bat. Source: Dr. Joel Mayerson

The main drawback to this operation is cosmetic.

The cosmetics of a foot at the knee position and then pointed backwards takes getting used to and some patients never get there. Typically, as was the case for Dugan, the patient’s calf muscle now serves as the thigh, while the ankle and foot act as knee and shin.

In Dugan’s case, Dr. Mayerson dedicated quite a bit of time with both Dugan and his parents to make sure they understood the cosmetic issues. But for Dugan, the chance to be fully mobile quickly outweighed any concerns over appearance. He and his parents knew that he had a lifetime in front of him and the freedom that a functional joint via rotationplasty represented a significant improvement over the use of traditional above-knee prosthesis.

Managing Growth

Dr. Mayerson’s second greatest concern, after cosmetics, was managing Dugan’s expected bone growth. “Most boys stop growing around age 17. In Dugan’s case, his untreated leg will grow faster than his rotationplasty leg. So we made Dugan’s rotationplasty leg approximately 7 centimeters longer than his other leg. By the time he his 17 years old, hopefully both legs will be of equal length at the level of the knee.”

The key for Dr. Mayerson was to determine Dugan’s skeletal age at the time of surgery and then make an accurate as possible guess at his amount of skeletal growth remaining until maturity. What complicates this algorithm is that growth plates at different parts of the leg and hip grow at different rates. Of the total growth that a patient can expect, the plates at the hip account for 30% of that future femur growth while plates at the knee contribute the remaining 70%. In the lower leg, plates at the ankle account for 40% of growth in the tibia and fibula, while those at the knee contribute the remaining 60%.

Since Dr. Mayerson and his team removed growth plates on either side of Dugan’s knee Mayerson compensated by making Dugan’s residual limb longer.

“The whole surgery took 8-9 hours and was performed at Nationwide Children’s Hospital in Columbus, Ohio, ” remembers Mayerson.

Rehabilitation

Mayerson’s team fitted Dugan with a prosthetic leg that fits over his foot and ankle, allowing him to walk, run and play sports. Recalls Mayerson: “The ankle joint functions exactly as a knee joint although it is not as stable side-to-side as a knee joint. The prosthesis helps to manage the side-to-side stability.”

Rehab for Dugan was slow at first. “Dugan had to undergo six more months of chemotherapy. During that period he fell down a couple of times. Once he broke his hip and another time he fell and broke his distal tibia just above the ankle (new knee). Dugan didn’t tell me about his fall and painful hip for a month. It wasn’t until we saw an X-ray that we discovered that he’d incurred a new fracture.”

When OTW commented that Dugan sounded like a pretty active 10 year old, Dr. Mayerson laughed and said, “Yes, you can’t keep Dugan still very long.”

Dugan also went through a long period of gait training but in 2010, Dugan returned to playing baseball and this year, according to Dr. Mayerson, “Dugan’s knee joint bends fully, so he’s recovered. Bottom line, this is an extremely functional operation if a patient is committed, as Dugan and his parents were, to really stick to it and to get past the cosmetics of it.”

So how do Dugan’s parents like it? “They think it’s great.”