title: Morphological classification of acromial spur: correlation between Rockwood tilt view and arthroscopic finding.
abstract: Purpose and hypothesis: Acromion spur is the extrinsic factor for impingement syndrome and rotator cuff tear. The Rockwood tilt view can be used to evaluate prominence of the anterior acromion, however no study has shown the correlation of findings between the Rockwood tilt view and the arthroscopic finding.
  
  
  METHODS
  We developed the arthroscopic classification of acromion spur as type 1 flat spur, type 2 bump spur, type 3 heel spur, type 4 keel spur, and type 5 irregular spur. Patients with rotator cuff syndrome who underwent arthroscopic surgery were recruited. Two observers were asked to classify the type of spur from arthroscopic findings and Rockwood tilt views separately in random pattern. The prevalence of supraspinatus tendon tear was also recorded as no tear, partial-thickness tear, and full-thickness tear.
  
  
  RESULTS
  The keel spur (33.9%) was the most common finding followed by the heel spur (27.8%). The correlation was high especially for the heel, the keel, and the irregular spur (75.47%, 74.03%, and 72.73%, respectively.) These three types of spurs have a high prevalence of full thickness of supraspinatus tendon tear.
  
  
  CONCLUSIONS
  The Rockwood tilt view can be used to evaluate the morphology of an acromion spur, especially the at-risk spur that correlates highly with the full-thickness supraspinatus tendon tear. The arthroscopic classification will also be a useful tool to improve communication between the surgeon and the guide for appropriate treatment in a rotator cuff tear patient when encountering the heel, keel, and irregular spur.
authors.affiliation: Department of Orthopaedics, Faculty of Medicine, Thammasat University, Paholyothin Road, Khlong Luang, Rangsit, Pathum Thani 12121, Thailand.
authors.forename: Pinkawas
authors.initials: P
authors.lastname: Kongmalai
authors.affiliation: Department of Orthopaedics, Faculty of Medicine, Thammasat University, Paholyothin Road, Khlong Luang, Rangsit, Pathum Thani 12121, Thailand.
authors.forename: Adinun
authors.initials: A
authors.lastname: Apivatgaroon
authors.affiliation: Department of Orthopaedics, Faculty of Medicine, Thammasat University, Paholyothin Road, Khlong Luang, Rangsit, Pathum Thani 12121, Thailand.
authors.forename: Bancha
authors.initials: B
authors.lastname: Chernchujit