An analysis of national variance in coding for patellofemoral instability

We sought to identify which specific set of codes are used by each acute NHS trust in England to document the diagnosis and management of patellofemoral instability (PFI).

All acute NHS Trusts in England were sent freedom of information (FOI) requests regarding their use of International Statistical Classification of Diseases and Related Health Problems version 10 (ICD-10) codes for the diagnoses related to PFI, and Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures 4th revision (OPCS-4) codes for surgical management of PFI.

106 of 132 (80%) relevant trusts who manage patients with PFI responded with information. Coding for diagnosis of patellar dislocation and recurrent dislocation were largely consistent with 96% of the trusts using the same code. However, coding of patellar instability varied widely with 10 different codes being used, the most common of which was being used by only 34% of trusts. Coding for operative management exhibited greater variety with the number of different codes being used by trusts for each of the eight surgical treatments ranging from 11 to 19 and the range for the most common code being used by trusts from 34% to 64%. Furthermore, a large number of trusts used multiple different codes for the same diagnosis or treatment of PFI.

There is a lack of uniformity in how trusts code PFI diagnosis and treatment. Standardisation will enable further research involving focused analysis of trust databases to facilitate a better understanding of the epidemiology of this condition.