A patient registry for orthopedic surgery. 
Identification of patient subpopulations for retrospective clinical studies, documentation of residents' clinical experience, and other administrative purposes can be difficult and time consuming.  The problem of identification is exacerbated when a teaching program involves several hospitals or when the desired subpopulation is not adequately defined by standard diagnosis or procedure codes used by the institution.  A useful patient registry system is reported here for the storage and retrieval of data on orthopedic patients treated by surgical residents at a major teaching hospital and its affiliates.  The registry uses a simple, yet powerful encoding scheme to describe patient entries.  In addition to a multidimensional encoded description based on SNOMED, the system supports the entry of free text to provide greater detail.  This combination gives the patient registry both power and versatility.