Hypothyroidism increases 90-day postoperative complications in patients undergoing primary single level anterior cervical disectomy and fusion: a matched control analysis

Abstract

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is indicated for patients suffering from cervical radiculopathy, myelopathy, and degenerative disc disease, among other diseases. There is paucity in the literature regarding postoperative complications in patients undergoing primary ACDF with a diagnosis of hypothyroidism. The purpose of this study is to compare 90-day postoperative complications in patients with and without hypothyroidism undergoing primary ACDF. METHODS: A retrospective analysis was completed using a national administrative database known as Pearl Diver (Pearl Diver Technologies, Fort Wayne, Indiana) using the International Classification of Disease, ninth revision (ICD-9) codes. The study group consisted of patients having undergone ACDF with an active diagnosis of hypothyroidism 90 days prior to and on the day of surgery. Patients undergoing primary ACDF without hypothyroidism served as the control group. Patients in both groups were randomly matched according to age, gender, and Charlson-Comorbidity Index (CCI). The 90-day postoperative medical complications were assessed along with readmission rates and total cost of care. RESULTS: There were a total of 107,066 patients equally divided between the 2 cohorts. Patients with hypothyroidism had greater odds of developing complications such as non-healing surgical wound (OR: 2.27; P<0.001), pulmonary embolus (OR: 2.16; P<0.001), myocardial infarction (OR: 2.10; P<0.001), compared to patients in the control group after undergoing primary ACDF. Readmission rates were also higher in patients with hypothyroidism (OR: 1.45; P<0.001). Total cost of care was also greater in patients with hypothyroidism compared to patients without hypothyroidism undergoing primary ACDF. CONCLUSIONS: Hypothyroidism is a risk factor for worse postoperative outcomes in patients undergoing primary ACDF. Appropriate preoperative optimization with thyroid hormone supplementation could potentially minimize the incidence of developing numerous medical complications, in addition to potentially lowering readmission rates and the total cost of care.