BACKGROUND: Psychiatric conditions and psychopharmacological treatments have been demonstrated to be important risk-factors for prolonged hospital length of stay, readmission and morbidity, following fast-track total hip (THA) and total knee arthroplasty (TKA).

AIMS: The aim of the study was to provide a detailed description of the preoperative psychiatric characteristics of a well-defined patient population undergoing THA and TKA, using the 90-item Symptom Checklist (SCL-90-R).

METHODS: A pre-surgical population of 2183 patients completed the full SCL-90-R prior to THA/TKA from 2015 to 2016. The SCL-90-R scale and total scores of the pre-surgical sample were compared to the scores of an age- and gender stratified Danish sample of healthy controls. A Mokken scalogram analysis was conducted to assess the scalability of the SCL-90-R in both samples.

RESULTS: The Mokken analysis yielded acceptable scalability coefficients above 0.30 in all subscales of the SCL-90-R except psycoticism (0.28). There was no clinically significant difference (effect size = <0.50) in the SCL-90-R total score between the pre-surgical and the healthy controls samples, although pre-surgical patients had lower mean scores compared to the healthy controls in all subscales except somatization (effect size = -0.22).

CONCLUSION: The Mokken analysis demonstrated that the SCL-90-R and its subscales express valid measures of psychopathology in our surgical sample. The psychiatric profile of the pre-surgical patient sample indicates that patients undergoing THA/TKA are not more burdened by psychiatric symptoms than a healthy control group with the exception of symptoms relating to somatization.