Abstract
Background
The hypertrophic changes that occur in the cartilage of an epiphysis prior to the onset of ossification are known as the pre-ossification center. Awareness of the appearance of the pre-ossification center on MR images is important to avoid confusing normal developmental changes with pathology.
Objective
The purpose of this study was to determine the characteristics of the trochlear pre-ossification center on MR imaging and examine age and gender differences.
Materials and methods
We retrospectively analyzed MR images from 61 children. The trochleas were categorized into three types on the basis of signal intensity (SI). Trochlear types were compared to age and gender.
Results
There was no significant difference between the ages of boys and girls. Type 1 trochleas showed homogeneous SI on all pulse sequences. Type 2 trochleas demonstrated a focus of high SI in the epiphyseal cartilage on fat-suppressed water-sensitive sequences, with high or intermediate SI on gradient-echo images (pre-ossification center). Type 3 trochleas showed low SI on fat-suppressed water-sensitive sequences and gradient-echo images. Thirty-seven trochleas were described as type 1, sixteen as type 2 and eight as type 3. ANOVAs confirmed a statistically significant difference in the age of children with type 3 trochleas and those with types 1 and 2 (P < 0.001). Spearman rank correlations determined a positive relationship between trochlear type and age of the children (r = 0.53).
Conclusion
Development-related changes in the trochlea follow a predictable pattern. The signal characteristics of the pre-ossification center likely reflect normal chondrocyte hypertrophy and an increase in free water in the matrix.
Similar content being viewed by others
References
Emery KH (2009) MR imaging in congenital and acquired disorders of the pediatric upper extremity. Magn Reson Imaging Clin N Am 17:549–570, vii
Chapman VM, Nimkin K, Jaramillo D (2004) The pre-ossification center: normal CT and MRI findings in the trochlea. Skeletal Radiol 33:725–727
Patel B, Reed M, Patel S (2009) Gender-specific pattern differences of the ossification centers in the pediatric elbow. Pediatr Radiol 39:226–231
Landis JR, Koch GG (1977) The measurement of observer agreement for categorical data. Biometrics 33:159–174
Jaramillo D, Waters PM (1997) MR imaging of the normal developmental anatomy of the elbow. Magn Reson Imaging Clin N Am 5:501–513
Yamaguchi K, Sweet FA, Bindra R et al (1997) The extraosseous and intraosseous arterial anatomy of the adult elbow. J Bone Joint Surg Am 79:1653–1662
Rivas R, Shapiro F (2002) Structural stages in the development of the long bones and epiphyses: a study in the New Zealand white rabbit. J Bone Joint Surg Am 84-A:85–100
Laor T, Jaramillo D (2009) MR imaging insights into skeletal maturation: what is normal? Radiology 250:28–38
Jaramillo D, Villegas-Medina OL, Doty DK et al (2004) Age-related vascular changes in the epiphysis, physis, and metaphysis: normal findings on gadolinium-enhanced MRI of piglets. AJR 182:353–360
Jaramillo D (2008) Cartilage imaging. Pediatr Radiol 38(Suppl 2):S256–S258
Babyn PS, Kim HK, Lemaire C et al (1996) High-resolution magnetic resonance imaging of normal porcine cartilaginous epiphyseal maturation. J Magn Reson Imaging 6:172–179
Oeppen RS, Connolly SA, Bencardino JT et al (2004) Acute injury of the articular cartilage and subchondral bone: a common but unrecognized lesion in the immature knee. AJR 182:111–117
Kendell SD, Helms CA, Rampton JW et al (2005) MRI appearance of chondral delamination injuries of the knee. AJR 184:1486–1489
Khanna PC, Thapa MM (2009) The growing skeleton: MR imaging appearances of developing cartilage. Magn Reson Imaging Clin N Am 17:411–421, v
Bydder M, Rahal A, Fullerton GD et al (2007) The magic angle effect: a source of artifact, determinant of image contrast, and technique for imaging. J Magn Reson Imaging 25:290–300
Wacker FK, Bolze X, Felsenberg D et al (1998) Orientation-dependent changes in MR signal intensity of articular cartilage: a manifestation of the ‘magic angle’ effect. Skeletal Radiol 27:306–310
Varich LJ, Laor T, Jaramillo D (2000) Normal maturation of the distal femoral epiphyseal cartilage: age-related changes at MR imaging. Radiology 214:705–709
Leonard MB, Elmi A, Mostoufi–Moab S et al (2010) Effects of sex, race, and puberty on cortical bone and the functional muscle bone unit in children, adolescents, and young adults. J Clin Endocrinol Metab 95:1681–1689
Jans LB, Jaremko JL, Ditchfield M et al (2011) Evolution of femoral condylar ossification at MR imaging: frequency and patient age distribution. Radiology 258:880–888
Conflict of interest
We have no conflicts of interest to declare.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jaimes, C., Jimenez, M., Marin, D. et al. The trochlear pre-ossification center: a normal developmental stage and potential pitfall on MR images. Pediatr Radiol 42, 1364–1371 (2012). https://doi.org/10.1007/s00247-012-2454-7
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00247-012-2454-7