Orthopaedic Surgeon Coaxes New Bone Growth in Adolescents to Correct Lower Leg Deformities

At age 14, Janiya Winston has gone through more surgeries than most people will ever have. Now, her journey is finally over. For the first time in her life, Janiya can walk without a limp or knee pain thanks to the pediatric orthopaedic team at the Medical University of South Carolina (MUSC) Shawn Jenkins Children's Hospital.

Janiya was born with a congenital condition called, Blount disease, which causes severe bowing of one or both legs.¹ If untreated, it can progress, leading to serious orthopaedic issues as a child matures and the bones and joints harden.² Robert F. Murphy, M.D., a pediatric orthopaedic surgeon and Chief of Pediatric Orthopaedics at MUSC Children's Health explains, "This disease causes disorganized growth at the growth plates around the knee that results in bow-leggedness because their legs don't grow straight."

This three-dimensional deformity combines varus, procurvatum, and internal rotation of the primary shin bone (the tibia), and leg-length differences.³ Weight-bearing on this abnormal growth pattern (simply by walking and other normal, childhood activities) causes the asymmetry to gradually get worse.⁴ If the bones cannot be straightened, using conservative measures before a child reaches six to eight years of age, surgical repair is usually required.⁵

Blount disease is more common in the Southeast than in other parts of the country, and risk factors include being overweight, having African-American ancestry and having other family members with the disease.⁶ Although the growth pattern sometimes normalizes on its own, for most children, treatment takes several years.⁷

 

"As soon as she started walking, both of her legs bowed out in a C-shape," says Janiya's mother, Jakeera Winston. "They put braces on her legs when she was little. Then as she got older, they put special shoes on her feet, but it kept getting worse. When she was about six or seven, they started putting screws in her knees – first one and then the other. She had surgery every year or two from then until now."

Although the etiology and mechanism of disease are not well understood, there is agreement that the best approach is to start with conservative therapies.⁸ "In many children, you can control and correct it with a guided growth technique that ushers the bone into a straight pattern," says Murphy. "Unfortunately, Janiya's disease recurred after we did some earlier corrective procedures. When she came back to see us, she was older and her growth plates were closed." In other words, Janiya was no longer growing and would need a more complex solution.

"When she bent her left knee, it turned in the opposite direction so her leg looked like a V-shape," says Jakeera. "She's an active, tough lady who loves to run and do TikTok dances, but she had the limp and pain that got in her way."

"It was what we call a multi-planar lower extremity deformity – meaning one of her legs was deformed in several directions. It was both bowed, rotated, and shorter than the other leg," says Murphy. "She had a lurching gait because of the leg length discrepancy, and she had constant pain. Her regular kid-life was disrupted because she couldn't do the things she wanted to do."

 

Fortunately, Janiya was a candidate to receive a device called the Taylor Spatial Frame. "It allows us to correct all planes of the deformity using a single surgical encounter and a single device," says Murphy. "We've learned that if you cut a bone in half and distract it – pull it apart – by a millimeter or two a day, you can coax it into growing again. It sounds totally crazy but, with the frame, we can perfectly dial in the leg straightness and length a little bit at a time. It's not painful, because it's such a slow process."

Janiya lived with her leg stabilized by a metal, cage-like device to provide external fixation for four months, while her body grew new, correctly aligned bone. "This cage was the biggest surgery she'd had," says Jakeera. "We were in the hospital for about a week, with family and friends helping out at home with her sisters. Then, Janiya had to use a wheelchair, crutches, and a walker to get around and go to school. But her sisters liked fussing over her and making sure she didn't fall. My two-year-old especially pampered her."

Each day, Jakeera turned one or more of the frame's six struts by a specified amount to coax the new bone to grow straight. When the frame came off, Janiya had a cast on her leg for two more weeks. "Once we take it off, the new bone hardens into solid, mature bone. It develops absolutely normally," says Murphy.

 

While the technique is applicable to patients of any age, younger children typically get faster results because their physiology allows them to grow bone more quickly and easily. But the Taylor Spatial Frame procedure has a very high success rate in patients of all ages. "Once we do the corrective procedure, it's fixed. That's it for rest of your life," says Murphy. "Because we see this deformity relatively frequently in our region, we're proud to be able to offer an advanced option to help these children. By normalizing their lower limb alignment, we let them get back to being kids, doing the things they want to do."

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¹Murthy D., De Leucio A. Blount Disease. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; Jan, 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560923/?report=classic. Last Update: July 28, 2021.
²Janoyer, M. Blount disease. Orthopaedics & Traumatology: Surgery & Research, 2019. 105:Spplmnt 1. Pgs.S111-S121. https://doi.org/10.1016/j.otsr.2018.01.009.
³Murthy D., De Leucio A. Blount Disease. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; Jan, 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560923/?report=classic. Last Update: July 28, 2021.
⁴de Pablos J, Arbeloa-Gutierrez L, Arenas-Miquelez A. Update on treatment of adolescent Blount disease. Curr Opin Pediatr. 2018 Feb;30(1):71-77.
⁵de Pablos J, Arbeloa-Gutierrez L, Arenas-Miquelez A. Update on treatment of adolescent Blount disease. Curr Opin Pediatr. 2018 Feb;30(1):71-77.
⁶Murthy D., De Leucio A. Blount Disease. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; Jan, 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560923/?report=classic. Last Update: July 28, 2021.
⁷Janoyer, M. Blount disease. Orthopaedics & Traumatology: Surgery & Research, 2019. 105:Spplmnt 1. Pgs.S111-S121. https://doi.org/10.1016/j.otsr.2018.01.009.
⁸Janoyer, M. Blount disease. Orthopaedics & Traumatology: Surgery & Research, 2019. 105:Spplmnt 1. Pgs.S111-S121. https://doi.org/10.1016/j.otsr.2018.01.009.