Table 1

Features of potential casesa of osteonecrosis

Number of potential cases

87

Age, years

21 to 92

Women

7 (8%)

Sites (confirmed casesb)

81 (85% of potential cases)

Femoral head

71 (88%)

Humerus

4 (5%)

Talus

2 (2%)

Carpal navicular

2 (2%)

Other foot/ankle

2 (2%)

Sites (incident casesc)

15

Femoral head

14 (93%)

Humerus

0

Talus

0

Carpal navicular

0

Other foot/ankle

1 (7%)


aPotential cases were identified by the presence of at least one ICD-9 (International Statistical Classification of Diseases and Related Health Problems, Ninth Revision) code for osteonecrosis (733.4×) in the medical record. bConfirmed cases were those in which osteonecrosis was present after reviewing the medical record. cIncident cases were those in which symptoms were noted in the medical record to have begun within 6 months of the first code.

Vlad et al. Arthritis Research & Therapy 2009 11:R89   doi:10.1186/ar2731

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