Andy Tsai1, Paul K Kleinman2, Tal Laor2, James R Kasser3. 1. Department of Radiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA. andy.tsai@childrens.harvard.edu. 2. Department of Radiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA. 3. Department of Orthopedics, Boston Children's Hospital, Boston, MA, USA.
Abstract
BACKGROUND: Fibular hemimelia is the most common congenital long-bone deficiency. It is usually unilateral and results in a limb-length discrepancy. The literature generally subscribes to the concept of constant inhibition, a process by which limb-length ratios between the shorter and longer extremity remain constant throughout growth, but scientific data supporting this concept are sparse. Additionally, recent literature suggests that these children have abnormal skeletal maturation. OBJECTIVE: To elucidate the lower-extremity long-bone growth patterns and skeletal maturation of children with unilateral fibular hemimelia. MATERIALS AND METHODS: We reviewed medical records of children with unilateral fibular hemimelia seen at a large pediatric hospital over a 17-year period. Inclusion criteria were: at least two scanograms prior to any shortening/lengthening procedure, and no other congenital or acquired disorders. We collected the study cohort's femoral and tibial lengths (scanogram reports), plotted them against patient chronological ages and compared them to published growth standards. When these children's bone ages (Greulich and Pyle) were available, we plotted them against the children's chronological ages. RESULTS: Twenty-three children were included (total=115 scanograms). At least 1 bone-age assessment was performed in 19 children (total=84 bone ages). All bone growth curves were within normal growth standards for the femur and tibia. Length ratios between shorter and longer limbs remained constant. Skeletal maturation was within two standard deviations of normal in 90% of bone ages. CONCLUSION: Lower-extremity long bones of children with unilateral fibular hemimelia have relatively normal growth curves, supporting and confirming the concept of constant inhibition. Most children show normal skeletal maturation.
BACKGROUND: Fibular hemimelia is the most common congenital long-bone deficiency. It is usually unilateral and results in a limb-length discrepancy. The literature generally subscribes to the concept of constant inhibition, a process by which limb-length ratios between the shorter and longer extremity remain constant throughout growth, but scientific data supporting this concept are sparse. Additionally, recent literature suggests that these children have abnormal skeletal maturation. OBJECTIVE: To elucidate the lower-extremity long-bone growth patterns and skeletal maturation of children with unilateral fibular hemimelia. MATERIALS AND METHODS: We reviewed medical records of children with unilateral fibular hemimelia seen at a large pediatric hospital over a 17-year period. Inclusion criteria were: at least two scanograms prior to any shortening/lengthening procedure, and no other congenital or acquired disorders. We collected the study cohort's femoral and tibial lengths (scanogram reports), plotted them against patient chronological ages and compared them to published growth standards. When these children's bone ages (Greulich and Pyle) were available, we plotted them against the children's chronological ages. RESULTS: Twenty-three children were included (total=115 scanograms). At least 1 bone-age assessment was performed in 19 children (total=84 bone ages). All bone growth curves were within normal growth standards for the femur and tibia. Length ratios between shorter and longer limbs remained constant. Skeletal maturation was within two standard deviations of normal in 90% of bone ages. CONCLUSION: Lower-extremity long bones of children with unilateral fibular hemimelia have relatively normal growth curves, supporting and confirming the concept of constant inhibition. Most children show normal skeletal maturation.