Use of Non-Specific Knee Diagnoses and Incidence of Obscure Knee Injuries in a Large Government Health System

Daniel I Rhon; Xiaoning Yuan; Brian T Barlow; Lisa N Konitzer; Chad E Cook

doi:10.2147/CLEP.S375040

Use of Non-Specific Knee Diagnoses and Incidence of Obscure Knee Injuries in a Large Government Health System

Clin Epidemiol. 2022 Oct 7:14:1123-1133. doi: 10.2147/CLEP.S375040. eCollection 2022.

Authors

Daniel I Rhon^{1

2}, Xiaoning Yuan², Brian T Barlow³, Lisa N Konitzer⁴, Chad E Cook^{5

6

7}

Affiliations

¹ Department of Rehabilitation Medicine, Brooke Army Medical Center, San Antonio, TX, USA.
² Department of Rehabilitation Medicine, School of Medicine, Uniformed Services University, Bethesda, MD, USA.
³ Department of Orthopaedic Surgery, Naval Medical Center Balboa, San Diego, CA, USA.
⁴ Department of Physical Medicine and Rehabilitation, Madigan Army Medical Center, Tacoma, WA, USA.
⁵ Department of Orthopaedics, School of Medicine, Duke University, Durham, NC, USA.
⁶ Duke Clinical Research Institute, Duke University, Durham, NC, USA.
⁷ Department of Population Health Sciences, Duke University, Durham, NC, USA.

Abstract

Purpose: Within a large government health system, to assess the practice of using non-specific diagnoses for knee disorders and determine how often they appear as the only diagnosis without more specificity. The secondary purpose was to identify the incidence of obscure knee disorders diagnosed: pes anserine bursitis, prepatellar bursitis, pigmented villonodular synovitis, and plica syndrome.

Patients and methods: Eligible beneficiaries of the Military Health System (MHS) seeking care for a knee disorder between 1 January 2009 and 31 December 2013 with at least 2-year follow-up. Data were sourced from the MHS Data Repository. The study outcomes were 1) utilization rate of non-specific knee diagnosis codes, 2) proportion of cases that never received a specific knee diagnosis, 3) incidence of obscure knee pathology in this cohort.

Results: There were 127,570 beneficiaries seeking care for knee pain during this period. While the majority (99.7%) initially received a non-specific knee diagnosis, these occurred in isolation for only 16.5% of the cases (n=20,042) over two-year follow-up. The use of non-specific codes was similar between military and civilian clinic settings (45.3% and 47.0%, respectively, of all knee disorders diagnosed), which appears to reflect clinical practice in which diagnoses become more specified over time and diagnostic workup aims to exclude competing diagnoses. The incidence of obscure knee pathology was small (0.2% to 4.0%).

Conclusion: Most of the cohort (99.7%) received a non-specific diagnosis at their initial visit, but only 15% did not eventually receive a more specific diagnostic code. These findings suggest that diagnoses may become more specific over time as condition-specific signs and symptoms become more evident, and diagnostic workup excludes competing diagnoses. A better understanding of diagnostic patterns and criteria for knee pain will improve the quality and interpretation from epidemiological studies.

Keywords: diagnosis; diagnostic criteria; electronic medical records; health services research; knee disorder; musculoskeletal injury.

Grants and funding

This work was funded by the Uniformed Services University, Department of Physical Medicine & Rehabilitation, Musculoskeletal Injury Rehabilitation Research for Operational Readiness (MIRROR) (HU00011920011).