Negative Association of Subclinical Hypothyroidism on Improvement in Patient-Reported Outcomes After Total Knee Arthroplasty

The purpose of this study is to analyze the potential influence of subclinical hypothyroidism (SCH) on improvement in patient-reported outcome measures following primary total knee arthroplasty.

A prospective, comparative cohort study between 92 SCH and 90 euthyroid patients was performed. Patients were followed up to 5 postoperative years. Patient-reported outcome measure was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. The Knee Society Scores were used for functional evaluation, and 5-point Likert scale for patient satisfaction. The Hospital Anxiety and Depression scale was also used.

All outcome scores significantly improved from preoperative to final follow-up in both groups (P = .001). There were no significant differences between groups in Knee Society Scores (P = .057) at the final follow-up, but Western Ontario and McMaster Universities Osteoarthritis Index scores were significantly lower in the SCH group (P = .015). Likewise, the patient satisfaction rate was significant lower in the SCH group (0.010).

SCH patients have a slower functional recovery than euthyroid patients, and trended toward lower improvements in patient-reported scores. Depression was the most important negative factor. The findings of this study can provide the surgeon with an important information for better counseling the SCH patients.