Table 3.

Definitions of osteophytes identified in the literature

Author (year)	Country	Study design	Age (mean)	Sample size (n)	Anatomical site		Definition
Okpala (2018) [52]	Nigeria	Retrospective	44.7	581 (329 cases, 252 controls)	Lumbar	‘…bony overgrowths especially at the anterior, lateral and less commonly, posterior aspects of the superior and inferior margins of vertebral bodies’
Middleto and Fish (2009) [51]	USA	Review	N/A	N/A	Lumbar	‘…bony outgrowths arising primarily along the anterior and lateral perimeters of the vertebral end-plate apophyses. These hypertrophic changes are believed to develop at sites of stress to the annular ligament and most commonly occur at thoracic T9–10 and lumbar L3 levels, vacuum phenomenon and vertebral body reactive change’.
Gallucci et al. (2007) [55]	Italy	Review	N/A	N/A	Cervical, Thoracic, Lumbar	‘Osteophytes are bony spurs that originate on the anterolateral aspect of the vertebral bodies a few millimetres from the margins of the disc space. Posterior osteophytes more frequently accompany osteophytes associated with osteochondrosis, microinstability and disc degeneration. They are characterized by a bulky triangular shape and have a marginal location’
Pitkanen et al. (2002) [54]	Finland	Retrospective	43	215	Lumbar	‘Traction spur defined as horizontally directed and arising at the site of attachment of the outermost annular fibres about 2 mm away from the distal border of the anterior and lateral surfaces’
Jaovisidha et al. (2000) [66]	Thailand	Retrospective	58.8	100	Lumbar	‘Osteophyte defined as a prominent bone proliferation along the anterior and lateral aspect of vertebral body.
Pfirrmann and Resnick (2001) [53]	USA	Retrospective	68.2	100	Thoracic, Lumbar	Large osteophytes were defined as outgrowths with an anteroposterior diameter was greater than 3 mm’. ‘Claw-type osteophytes were defined as excrescences arising from the discovertebral junction that were triangular and curved at their tip; traction osteophytes were defined as linear osseous plates extending in a horizontal direction throughout their length’.
Katevuo et al. (1985) [67]	Finland	Prospective	46.2	311	Cervical, Thoracic	‘Spondylosis was recorded if there were changes in more than two vertebrae and if there was osteophytes longer than 2 mm’.

N/A: Not applicable; USA: United States of America.