Persistent pain following total knee arthroplasty: The role of underlying diseases.

Background: With increasing age and joint-destructive diseases, the need for novel surgeries such as total knee arthroplasty (TKA) has increased. Complications such as pain exacerbation and persistent pain after surgery may occur which increases rehabilitation programs. Factors such as body mass index (BMI), psychiatric disorders, spine diseases, and comorbidities diseases can affect outcomes. Our study was conducted to evaluate the effect of BMI, psychiatric disorders, spine diseases, and underlying diseases on persistent and annoying pain after TKA.

Materials and methods: This is a case-control study that was conducted on patients who underwent TKA in Kashani Hospital in Isfahan City in 2020-2022. Demographic data of patients including age and BMI, diabetes mellitus (DM), history of psychiatric disorders, spine disorders such as spondylolisthesis or disc herniation, and other underlying diseases were obtained. Patients were assigned to case or control groups based on pain complaints after surgery. All patients were evaluated 6 months after the initial surgery. After collecting the study data, they were entered into SPSS software (version 25, IBM Corporation, Armonk, NY, USA) and analyzed.

Results: We enrolled 35 patients in the case group and 39 patients in the control group between June 2020 and September 2022, based on the severity of pain measured using a Visual Analog Scale score. Our results show that BMI and DM had a meaningful relationship with pain after surgery (P ≤ 0.01). Other factors did not show a significant difference between groups.

Conclusion: Underlying diseases, psychiatric diseases, and spine disorders did not significantly affect the pain after TKA. Patients with DM and higher BMI experienced more persistent pain after TKA.