title: Radiographic evaluation of posttraumatic osteoarthritis of the ankle: the Kellgren-Lawrence scale is reliable and correlates with clinical symptoms.
abstract: OBJECTIVE
  To assess reliability and construct validity of the Kellgren-Lawrence (K&L) scale in posttraumatic ankle osteoarthritis (OA); additionally evaluate the validity of including tibiotalar tilting in the scale.
  
  
  METHODS
  One-hundred and fifty ankle radiographs (75 patients, unilateral malleolar fractures) evaluated at average of 18 years after surgery. American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot (HF) score and pain (visual analog scale) were recorded. Grading of OA according to K&L criteria and identification of OA features was performed on standardized radiographs by four physicians. Minimal joint space width, sclerosis, and talar tilt angle were quantified by digital measurements. A modified K&L scale including talar tilting is presented. Validity of original and modified scale was evaluated and expressed as ability to (1) Identify those with clinical symptoms of ankle OA; and (2) Distinguish between different degrees of fracture severity.
  
  
  RESULTS
  Inter- and intra-observer reliability of OA assessment according to K&L were good (ICC 0.61 and 0.75). Original and modified K&L grades significantly increased with decreasing AOFAS ankle-HF scores and greater pain. A talar-tilt angle > 2° compared with ≤ 2° in grade 3 was associated with significantly higher pain levels (VAS pain 4.2 vs 1.4, respectively; mean difference 2.8, 95% CI 0.5-5.1). More severe fracture patterns at time of surgery were more often in patients with the highest K&L grades.
  
  
  CONCLUSIONS
  The K&L scale is a valid and reliable radiographic grading system for assessment of ankle OA. Inclusion of the talar tilt angle might allow for better differentiation with respect to clinical outcomes.
authors.affiliation: Division of Orthopedics and Trauma Surgery, Geneva University Hospital, Switzerland. Electronic address: nicolas.holzer@hcuge.ch.
authors.forename: N
authors.initials: N
authors.lastname: Holzer
authors.affiliation: Division of Orthopedics and Trauma Surgery, Geneva University Hospital, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Salvo
authors.affiliation: Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, The Netherlands.
authors.forename: A C A
authors.initials: AC
authors.lastname: Marijnissen
authors.affiliation: Imaging Sciences Institute, University Medical Center Utrecht, The Netherlands.
authors.forename: K L
authors.initials: KL
authors.lastname: Vincken
authors.affiliation: Division of Orthopedics and Trauma Surgery, Geneva University Hospital, Switzerland.
authors.forename: A C
authors.initials: AC
authors.lastname: Ahmad
authors.affiliation: Division of Orthopedics and Trauma Surgery, Geneva University Hospital, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Serra
authors.affiliation: Division of Orthopedics and Trauma Surgery, Geneva University Hospital, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Hoffmeyer
authors.affiliation: Division of Orthopedics and Trauma Surgery, Geneva University Hospital, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Stern
authors.affiliation: Division of Orthopedics and Trauma Surgery, Geneva University Hospital, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Lübbeke
authors.affiliation: Division of Orthopedics and Trauma Surgery, Geneva University Hospital, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Assal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D064386:Ankle Fractures / Q000150:complications* / Q000601:surgery; D000843:Ankle Joint / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D054850:Osteophyte / Q000000981:diagnostic imaging*; D010147:Pain Measurement; D011859:Radiography; D015203:Reproducibility of Results; D013628:Talus / Q000000981:diagnostic imaging*; D013977:Tibia / Q000000981:diagnostic imaging*
keywords: Ankle; Kellgren and Lawrence; Osteoarthritis; Radiography; Reliability; Validity