Radiographic predictability of cartilage damage in medial ankle osteoarthritis.
BACKGROUND
Radiographic grading has been used to assess and select between treatment options for ankle osteoarthritis. To use radiographic grading systems in clinical practice and scientific studies one must have reliable systems that predict the fate of the cartilage.


OBJECTIVE
We therefore asked whether (1) radiographic grading of ankle osteoarthritis is reliable and (2) grading reflects cartilage damage observed during arthroscopy. We then (3) determined the sensitivity, specificity, and predictive values of the radiographic findings.


METHODS
We examined 74 ankles with medial osteoarthritis and 24 with normal articular cartilage based on arthroscopy. Arthroscopic findings were graded according to the modified Outerbridge grades and all radiographs were graded using the modified Kellgren-Lawrence, Takakura et al., and van Dijk et al. grading systems. The reliability of each radiographic grading system was evaluated. We correlated the radiographic grades and severity of cartilage damage for each radiographic grading system. Sensitivity, specificity, and predictive values of spurs and joint space narrowing with or without talar tilting then were determined.


RESULTS
The interobserver weighted kappa ranged from 0.58 to 0.89 and the intraobserver weighted kappa from 0.51 to 0.85. The correlation coefficients for the Kellgren-Lawrence, Takakura et al., and van Dijk et al. grades were 0.53, 0.42, and 0.42, respectively. Ankles with medial joint space narrowing (Stage 2 of Takakura et al. and van Dijk et al. grades) showed varying severity of cartilage damage. The positive predictive value of cartilage damage increased from 77% for medial joint space narrowing regardless of the presence of talar tilting to 98% for medial joint space narrowing with talar tilting.


CONCLUSIONS
Our observations suggest the inclusion of talar tilting in grading schemes enhances the assessment of cartilage damage.


METHODS
Level II, diagnostic study. See the Guidelines for Authors for a complete description of level of evidence.
Moon
Jeong-Seok
JS
Department of Orthopaedic Surgery, Seoul Paik Hospital, College of Medicine, Inje University, Jung-Gu, Seoul 100-032, Korea.
Shim
Jae-Chan
JC
Suh
Jin-Soo
JS
Lee
Woo-Chun
WC
D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D001182:Arthroscopy / Q000379:methods*; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010003:Osteoarthritis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies
Radiology. 2006 Jun;239(3):818-24
16641340
Acta Orthop Scand. 1973;44(1):69-74
4702611
Osteoarthritis Cartilage. 1999 Mar;7(2):239-46
10222223
Arthroscopy. 1987;3(3):161-5
3675786
Foot Ankle Int. 2005 Nov;26(11):908-12
16309602
Osteoarthritis Cartilage. 1997 Mar;5(2):87-97
9135820
Ann Rheum Dis. 1966 Jan;25(1):1-24
5905334
J Bone Joint Surg Br. 1961 Nov;43-B:752-7
14038135
Foot Ankle Int. 2000 Aug;21(8):657-64
10966363
J Bone Joint Surg Br. 2006 Jul;88(7):909-13
16798994
Clin Exp Rheumatol. 1998 Jan-Feb;16(1):15-20
9543556
J Rheumatol. 1993 Nov;20(11):1911-8
8308778
J Rheumatol. 1994 Apr;21(4):675-9
8035392
Am J Sports Med. 2003 Jan-Feb;31(1):83-6
12531763
Osteoarthritis Cartilage. 2003 Aug;11(8):580-4
12880580
Arthroscopy. 1997 Aug;13(4):456-60
9276052
Scand J Rheumatol. 1997;26(3):155-65
9225869
Arthritis Rheum. 1991 Apr;34(4):377-82
2012624
Osteoarthritis Cartilage. 1998 May;6(3):160-6
9682782
J Rheumatol. 2000 Jun;27(6):1513-7
10852280
J Bone Joint Surg Br. 1997 Mar;79(2):280-4
9119857
AJR Am J Roentgenol. 2006 Sep;187(3):794-9
16928947
J Bone Joint Surg Br. 1995 Jan;77(1):50-4
7822395
Clin Orthop Relat Res. 2007 Sep;462:156-68
17563701
J Bone Joint Surg Br. 2003 May;85(4):550-3
12793562
Acta Radiol. 1997 Nov;38(6):1063-70
9394671
Int Orthop. 2000;24(1):36-9
10774860
Foot Ankle Int. 2004 Feb;25(2):63-8
14992704
Clin Orthop Relat Res. 2006 Jan;442:245-51
16394768
Arthritis Rheum. 2003 Mar;48(3):675-81
12632420
Invest Radiol. 1993 Jun;28(6):497-501
8320066
J Bone Joint Surg Am. 1988 Dec;70(10):1479-83
3198672
Semin Arthritis Rheum. 2005 Dec;35(3):197-201
16325660
Foot Ankle Int. 2004 Feb;25(2):59-62
14992703
Ann Rheum Dis. 1957 Dec;16(4):494-502
13498604
Semin Arthritis Rheum. 1997 Feb;26(4):667-74
9062947
Iowa Orthop J. 2005;25:44-6
16089071
Ann Rheum Dis. 1991 Jul;50(7):467-70
1877852
Skeletal Radiol. 2006 Dec;35(12):895-902
16680465
Semin Arthritis Rheum. 1991 Jun;20(6 Suppl 2):40-7
1866629
Ann Rheum Dis. 1991 Jan;50(1):8-13
1994877
Foot Ankle Clin. 2006 Sep;11(3):663-83
16971256
Foot Ankle Int. 2003 Apr;24(4):317-20
12735373
J Bone Joint Surg Br. 2005 Jan;87(1):41-6
15686236
J Bone Joint Surg Br. 1993 May;75(3):437-40
8496216
J Rheumatol. 1996 Nov;23(11):1938-42
8923371
Rheum Dis Clin North Am. 2008 Aug;34(3):623-43
18687276
Clin Orthop Relat Res. 2004 Oct;(427 Suppl):S6-15
15480076
Arthritis Rheum. 1991 Nov;34(11):1381-6
1953815
Foot Ankle Int. 2008 Apr;29(4):400-6
18442455
Foot Ankle Int. 1999 Dec;20(12):789-93
10609707
Eur J Radiol. 1998 May;27 Suppl 1:S70-3
9652504
J Rheumatol. 1996 Apr;23(4):698-706
8730130