title: Callus formation in the humerus compared with the femur and tibia during limb lengthening.
abstract: We investigated whether the callus formation in the humerus during the distraction period of limb lengthening proceeds at a higher rate than that in the femur and tibia. Ten achondroplastic patients underwent 3 bilateral humerus, 3 bilateral femur and 4 bilateral tibia lengthenings. To reduce the confounding effect of bone size, we used bone mineral apparent density (BMAD) to compare the three groups; this is a volumetric bone mineral density measurement. BMAD in the distracted callus space was evaluated at 8 weeks after the start of distraction using dual-energy X-ray absorptiometry (mean +/- SD; g/cm3): in the humerus (0.24 +/- 0.08) it was significantly higher than in the tibia (0.10 +/- 0.02), while there was no difference between the humerus and femur (0.35 +/- 0.11). We conclude that the callus formation in the humerus during the distraction period of limb lengthening proceeded at a significantly faster rate than in the tibia, but there was no significant difference between the humerus and femur.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Matsushita
authors.forename: S
authors.initials: S
authors.lastname: Horinaka
authors.forename: I
authors.initials: I
authors.lastname: Kusaba
authors.forename: T
authors.initials: T
authors.lastname: Kurokawa
mesh_terms: D000130:Achondroplasia / Q000473:pathology / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D015519:Bone Density / Q000502:physiology; D002146:Bony Callus / Q000473:pathology; D002648:Child; D005260:Female; D005269:Femur / Q000473:pathology / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D006811:Humerus / Q000473:pathology / Q000601:surgery*; D008297:Male; D019857:Osteogenesis, Distraction; D013977:Tibia / Q000473:pathology / Q000601:surgery*