Accuracy of ICD-10 Coding for Femoral Head Bearing Surfaces in Hip Arthroplasty

The International Classification of Diseases-10 Procedure Code System (ICD-10-PCS) introduced oxidized zirconium (OxZi) and niobium procedural codes to the types of femoral head bearing surfaces in 2017. These codes aimed to increase procedural specificity in coding and improve data collection through administrative claims databases. This study aimed to assess the accuracy of ICD-10-PCS coding for femoral head bearing surfaces (cobalt chrome/metal, ceramic, and OxZi) in hip procedures.

A retrospective analysis of 6,204 procedures utilizing femoral heads performed between October 1, 2017 and August 26, 2021 at a large, urban academic hospital was conducted. Operative reports and implant logs were queried to determine the femoral head bearing surface, which was used during the total hip arthroplasty. These results were then compared to the ICD-10-PCS codes in the billing records. Coding accuracy was subsequently determined and statistical differences between the three groups were evaluated.

The ICD-10-PCS coding was accurate for 90.8% (5,634/6,204) of cases. Coding accuracy for ceramic femoral heads (95.4%, 4,171/4,371) was significantly greater than that of both cobalt chrome/metal (73.7%, 606/822; P < .001) and OxZi (84.8%, 857/1,011; P < .001) femoral heads.

While coding for ceramic femoral heads was very accurate, OxZi and cobalt chrome/metal femoral heads were miscoded at a rate of approximately 20%. These inaccuracies call for further evaluation of the ICD-10-PCS coding process to ensure that conclusions drawn from clinical research performed through administrative claims databases are not subject to error.