Throckmorton sign, also known as John Thomas sign, refers to when the penis points in the direction of unilateral disease, typically of the pelvis or hip.
Throckmorton sign is a slang term used humorously by medical students and residents.
According to the first serious study of the sign published in 1988, the sign is less accurate than tossing a coin 2. This finding was supported by another subsequent study and also a meta-analysis 5,7.
History and etymology
It is named after Thomas "Tom" Bentley Throckmorton (1885-1961) 1,5, American neurologist and governor of the Iowa chapter of the American College of Physicians. He was not Governor of the State of Iowa, as is erroneously stated on several well-known websites!
In one specific Iranian institution it is known as Solooki sign, and this is only referenced in one paper, with a lack of evidence of it being used elsewhere 3.
Oram sign is also referred to in a single Scandinavian article, from Denmark, and is thought to derive from 'ormr', a word in Old Norse meaning serpent 4,5.
In France, Roy-Camille sign refers to the clinical finding in paraplegia that the penis assumes the laterality of the medullary lesion 5. It is named for Raymond Roy-Camille (1927-1994), a French orthopedic surgeon, famous for his advances in spinal surgery 6.
- 1. Patel DA, Swan KG. Francis Xavier Dercum: a man for all seasons. (2014) Annals of clinical and translational neurology. 1 (3): 233-7. doi:10.1002/acn3.36 - Pubmed
- 2. Thomas MC, Lyons BD, Walker RJ. John Thomas sign: common distraction or useful pointer?. (1998) The Medical journal of Australia. 169 (11-12): 670. Pubmed
- 3. Solooki S, Vosoughi A. (2010). John Thomas sign: is it helpful to determine the lower limb fracture?. Pakistan Journal of Radiology. 20:134-135.
- 4. Brink O, Borris LC, Andersen K, Hougaard K. [Oram's sign for hip or pelvic disorder]. (2009) Ugeskrift for laeger. 171 (51): 3760-3. Pubmed
- 5. Murphy IG, Murphy CG, Heffernan EJ. John Thomas sign--a memorable but misleading sign in hip fractures. (2014) Orthopaedics & traumatology, surgery & research : OTSR. 100 (2): 199-202. doi:10.1016/j.otsr.2013.12.017 - Pubmed
- 6. Mazel C. In memoriam. Raymond Roy-Cammille (25.4.1927-14.07.1994). (1994) La Chirurgia degli organi di movimento. 79 (4): 445-7. Pubmed
- 7. Gerber L, Laher AE, Enyuma COA, McDowall J, Aigbodion SJ, Buchanan S, Adam A. The 'John Thomas' sign and pelvic fractures-Fact or humorous myth?: A systematic review and meta-analysis. (2019) Journal of clinical orthopaedics and trauma. 10 (1): 161-166. doi:10.1016/j.jcot.2017.10.008 - Pubmed