The Journal of Arthroplasty, Volume 31, Issue 12, 2692 - 2695

American Association of Hip and Knee Surgeons–Endorsed Comorbidity Coding for Total Joint Arthroplasty: How Often Did We Hit the Mark With International Classification of Diseases, Ninth Revision?

Lan, Roy H. et al.
Hip Knee


Initiatives led by the American Academy of Orthopaedic Surgeons and the American Association of Hip and Knee Surgeons (AAHKS) have indicated a number of clinical risk factors associated with total joint arthroplasty that might reflect the complexity of contemporary hip and knee care. This study sought to examine the prevalence of specific International Classification of Diseases, Ninth Revision (ICD-9), coding with respect to an AAHKS-endorsed list of comorbidity codes.


An administrative data set from an academic arthroplasty referral center was analyzed in an attempt to measure the prevalence of clinical risk factors (ICD-9) endorsed by AAHKS. Total, partial, and revision joint arthroplasty procedures from January 1, 2012, to April 27, 2015, were included. Demographic data, along with diagnosis and procedural coding data, were collected and analyzed.


Results analysis found a number of poorly coded variables. The following variables were omitted in the data: narcotic use, worker’s compensation status, previous intra-articular infection, previous open reduction and internal fixation knee, and depression/psychiatric disease. Likewise, there was a discrepancy between the rate of ICD coding for obesity and body mass index measurements and categorization recorded in the clinic.


From this single-center study, there remain opportunities for coding to adequately reflect the comorbidities and complexities of patients undergoing arthroplasty.

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