"Pathological" fractures in spinal cord injuries and disorders: Insight into International classification of diseases, ninth revision coding.

OBJECTIVE

Analyses of osteoporosis-related fractures in persons with Spinal Cord Injury or Disorder (SCID) using administrative data often exclude pathological fractures (International Classification of Diseases, Ninth Revision (ICD-9) codes 733.1x). We examined how often lower extremity "pathological" fractures were secondary to osteoporosis.

DESIGN

Retrospective case-control study, fiscal years 2005-2015.

SETTING

Veterans Health Administration.

PARTICIPANTS

Veterans with SCID and an ICD-9 code for lower extremity fracture.

OUTCOME MEASURES: Clinical and SCID-related characteristics were compared in pathological and non-pathological fractures. A subset of Veterans with lower extremity fracture had data on fracture etiology from prior electronic health record (eHR) review. Of these, all with eHR-confirmed pathological fractures were considered cases. For each case, four unmatched controls with non-pathological fractures from this subset were randomly selected. Fracture etiology was compared between subsample cases and controls. We sought expert opinion from specialists who care for these fractures to understand their perspectives on what constitutes a pathological fracture and narrate our findings.

RESULTS

6,397 Veterans sustained 16,279 lower extremity fractures, including 314 (1.93%) pathological fractures in 264 Veterans. Ten of 13 (76.9%) cases of pathological fracture (76.9%) and 82.4% of non-pathological fractures were secondary to osteoporosis. Of the 19 experts surveyed, only two coded osteoporotic fractures as pathological.

CONCLUSION

Most pathological lower extremity fractures by ICD-9 codes in SCID are secondary to osteoporosis. Pathological fractures can be considered for inclusion in epidemiologic studies of osteoporosis in SCID when the risk-benefit profile for the study favors capturing all osteoporotic fractures at the expense of some misclassification.