Abstract
A “normal variant” is defined as an incidental, usually asymptomatic, imaging finding that simulates true pathology. Given the nearly limitless spectrum of skeletal variation, a solid understanding of commonly encountered normal radiographic variants is essential to avoid mistaking one for true pathology. Similarly, a familiarity with those “normal” variants that are known to, at times, become symptomatic is essential to help direct further work-up when the clinical findings are suggestive of a potentially painful variant.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
References
Ajmal M, O’Rourke SK (2005) Odontoid lateral mass interval (OLMI) asymmetry and rotary subluxation: a retrospective study in cervical spine injury. J Surg Orthop Adv 14:23–26
Anwar R, Anjum SN, Nicholl JE (2005) Sesamoids of the foot. Curr Orthop 19:40–48
Arvan B, Fournier-Gosselin MP, Fehlings MG (2010) Os odontoideum: etiology and surgical management. Neurosurgery 66:A22–A31
Bernaerts A, Vanhoenacker FM, Van de Perre S et al (2004) Accessory navicular bone: not such a normal variant. JBR-BTR 87:250–252
Billmann F, Bokor-Billmann T, Burnett C et al (2013) Occurrence and significance of odontoid lateral mass interspace asymmetry in trauma patients. World J Surg 37:1988–1995
Carr RB, Tozer Fink KR, Gross JA (2012) Imaging of trauma: part 1, pseudotrama of the spine – osseous variants that may simulate injury. AJR Am J Roentgenol 199:1200–1206
Cushing KE, Ramesh V, Gardner-Medwin D et al (2001) Tethering of the vertebral artery in the congenital arcuate foramen of the atlas vertebra: a possible cause of vertebral artery dissection in children. Dev Med Child Neurol 43:491–496
Dai L, Yuan W, Ni B et al (2000) Os odontoideum: etiology diagnosis and management. Surg Neurol 53:106–109
Dar G, Masharawi Y, Peleg S et al (2010) Schmorl’s nodes distribution in the human spine and its possible etiology. Eur Spine J 19:670–675
Doukas A, Petridis AK (2010) A case of aplasia of the posterior arch of the atlas mimicking fracture: review of the literature. Clin Anat 23:881–882
Fidas A, McDonald HL, Elton RA et al (1987) Prevalence and patterns of spina bifida occulta in 2707 normal adults. Clin Radiol 38:537–542
Freyschmidt J, Brossmann J, Wiens J, Sternberg A (eds) (2003) Borderlands of normal and early pathological findings in skeletal radiography. Thieme, New York
Gaca AM, Barnhart HX, Bisset GS (2010) Evaluation of wedging of lower thoracic and upper lumbar vertebral bodies in the pediatric population. AJR Am J Roentgenol 194:516–520
Gantopadhyay S, Aslam M (2003) Posterior arch defects of the atlas: significance in trauma and literature review. Eur J Emerg Med 10:238–240
Gheorghiu D, Leinekkugel A (2010) The linea aspera-pilaster complex as a possible cause of confusion with the ‘flame sign’: a case report. Acta Orthop Traumatol Turc 44:254–256
Helms CA (1978) Pseudocysts of the humerus. AJR Am J Roentgenol 131:287–288
Henales V, Hervas JA, Lopez P et al (1993) Intervertebral disc herniations (limbus vertebrae) in pediatric patients: report of 15 cases. Pediatr Radiol 23:608–610
Ho VB, Kransdorf MJ, Jelinek JS et al (1991) Dorsal defect of the patella: MR feature. J Comput Assist Tomogr 15:474–476
Hoeffel C, Munier G, Hoeffel JC (1993) The femoral linea aspera: radiological pattern. Eur Radiol 3:357–358
Huang MJ, Glaser JA (2003) Complete arcuate foramen precluding C1 lateral mass screw fixation in a patient with rheumatoid arthritis: case report. Iowa Orthop J 23:96–99
Jaremko JL, Siminoski K, Firth GB et al (2015) Common normal variants of pediatric vertebral development that mimic fractures: a pictorial review from a national longitudinal bone health study. Pediatr Radiol 454:593–605
Karasick D, Schweitzer ME (1996) The os trigonum syndrome: imaging features. AJR Am J Roentgenol 166:125–129
Karasick D, Schweitzer ME (1998) Disorders of the hallux sesamoid complex: MR features. Skeletal Radiol 24:411–418
Kavanagh EC, Zoga A, Omar I et al (2007) MRI findings in bipartite patella. Skeletal Radiol 36:209–214
Keats TE, Anderson MW (eds) (2013) Atlas of normal roentgen variants that may simulate disease, 9th edn. Philadelphia, Elsevier
Lawson JP (1994) Clinically significant radiologic anatomic variants of the skeleton. AJR Am J Roentgenol 163:249–255
Lee S, Joyce S, Seeger J (1986) Asymmetry of the odontoid-lateral mass interspaces: a radiographic finding of questionable clinical significance. Ann Emerg Med 15:1173–1176
Masharawi Y, Salame K, Mirovsky Y et al (2008) Vertebral body shape variation in the thoracic spine: characterization of its asymmetry and wedging. Clin Anat 21:46–54
Matsumoto M, Okada E, Kaneko Y et al (2011) Wedging of vertebral bodies at the thoracolumbar junction in asymptomatic healthy subjects on magnetic resonance imaging. Surg Radiol Anat 33:223–228
Mellado JM, Ramos A, Salvado E et al (2003) Accessory ossicles and sesamoid bones of the ankle and foot: imaging findings, clinical significance and differential diagnosis. Eur Radiol 13:L164–L177
Miller TT, Staron RB, Feldman F et al (1995) The symptomatic accessory tarsal navicular bone: assessment with MR imaging. Radiology 195:849–853
Mosel LD, Kat E, Voyvodic F (2004) Imaging of the symptomatic type II accessory navicular bone. Australas Radiol 48:267–271
Nault M-L, Kocher MS, MIcheli LJ (2014) Os trigonum syndrome. J Am Acad Orthop Surg 22:545–553
Nguyen MS, Kheyfits V, Giordano BD et al (2013) Hip anatomic variants that may mimic pathologic entities on MRI: nonlabral variants. AJR Am J Roentgenol 201:W401–W408
Oohashi Y, Koshino T, Oohashi Y (2010) Clinical features and classification of bipartite or tripartite patella. Knee Surg Sports Traumatol Arthrosc 18:1465–1469
Perdikakis E, Grigoraki E, Karantanas A (2011) Os naviculare: the multi-ossicle configuration of a normal variant. Skeletal Radiol 40:85–88
Pfirrmann CW, Resnick D (2001) Schmorl nodes of the thoracic and lumbar spine: radiographic-pathologic study of prevalence, characterization, and correlation with degenerative changes of 1,650 spinal levels in 100 cadavers. Radiology 219:368–374
Sammarco VJ (2000) Os acromiale: frequency, anatomy, and clinical implications. J Bone Joint Surg Am 82:394–400
Sankar WN, Wills BPD, Dormans JP et al (2006) Os odontoideum revisited: the case for a multifactorial etiology. Spine 31:979–984
Smoker WRK (1994) Craniovertebral junction: normal anatomy, craniometry, and congenital anomalies. Radiographics 14:255–277
Sobel M, Pavlov H, Geppert MJ et al (1994) Painful os peroneum syndrome: a spectrum of conditions responsible for plantar lateral foot pain. Foot Ankle Int 15:112–124
Stabler A, Belian M, Weiss M et al (1997) MR imaging of enhancing intraosseous disk herniation (Schmorl’s nodes). AJR Am J Roentgenol 168:933–938
Stubbs DM (1992) The arcuate foramen. Variability in distribution related to race and sex. Spine 17:1502–1504
Sutherland JP, Yaszemski MJ, White AA (1995) Radiographic appearance of the odontoid lateral mass interspace in the occiptoatlantoaxial complex. Spine 20:2221–2225
Swishchuk LE, John SD, Allbery S (1998) Disk degenerative disease in childhood: Scheuermann’s disease, Schmorl’s nodes, and the limbus vertebra: MRI findings in 12 patients. Pediatr Radiol 28:334–338
Van Holsbeeck M, Vandamme B, Marchal G et al (1987) Dorsal defect of the patella: concept of its origin and relationship with bipartite and multipartite patella. Skeletal Radiol 16:304–311
Wagner AL, Murtagh FR, Arrington JA et al (2000) Relationship of Schmorl’s nodes to vertebral body endplate fractures and acute endplate disk extrusions. AJNR Am J Neuroradiol 21:276–281
Walters G, Coumas JM, Akins CM et al (1991) Magnetic resonance imaging of acute symptomatic Schmorl’s node formation. Pediatr Emerg Care 7:294–296
Wang XT, Rosenberg ZS, Mechlin MB et al (2005) Normal variants and diseases of the peroneal tendons and superior peroneal retinaculum: MR imaging features. Radiographics 25:587–602
Zander G (1943) Os acetabuli and other bone nuclei; periarticular calcifications at the hip joint. Acta Radiol 24:317–327
Zhang Z, Zhou Y, Wang J et al (2010) Acute traumatic cervical cord injury in patients with os odontoideum. J Clin Neurosci 17:1289–1293
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2017 Springer International Publishing AG
About this chapter
Cite this chapter
Anderson, M.W. (2017). Radiographic Normal Variants. In: Peh, W. (eds) Pitfalls in Musculoskeletal Radiology. Springer, Cham. https://doi.org/10.1007/978-3-319-53496-1_11
Download citation
DOI: https://doi.org/10.1007/978-3-319-53496-1_11
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-53494-7
Online ISBN: 978-3-319-53496-1
eBook Packages: MedicineMedicine (R0)