[Safety and effectiveness of total hip arthroplasty in patients with hypothyroidism]

To evaluate the safety and effectiveness of total hip arthroplasty (THA) in patients with hypothyroidism.

Sixty-three patients with hypothyroidism (hypothyroidism group) and 63 euthyroid patients without history of thyroid disease (control group) who underwent primary unilateral THA between November 2009 and November 2018 were enrolled in this retrospective case control study. There was no significant difference between the two groups in gender, age, body mass index, hip side, reason for THA, American Society of Anesthesiology (ASA) classification, preoperative hemoglobin (Hb) level, and preoperative Harris score ( P>0.05). The perioperative thyroid stimulating hormone (TSH) and thyroxine (T ₄) levels, the hypothyroidism-related and other complications during hospitalization, the decrease in Hb, perioperative total blood loss, blood transfusion rate, length of hospital stays, and 90 days readmissions rate in the two groups were recorded and evaluated. The periprosthetic joint infection, aseptic loosening of the prosthesis, and hip Harris score during follow-up were recorded.

The differences in the TSH and T ₄ of hypothyroidism group between pre- and 3 days post-operation were significant ( P>0.05) and no hypothyroidism-related complications occurred after THA. The decrease in Hb and perioperative total blood loss in the hypothyroidism group were significantly higher than those in the control group ( P<0.05), but there was no significant difference between the two groups in terms of transfusion rate, length of hospital stays, and 90 days readmission rates ( P>0.05). No significant difference in the rate of complications (liver dysfunction, heart failure, pulmonary infection, urinary infection, and wound complication) between the two groups was found ( P>0.05) except for the rate of intramuscular vein thrombosis which was significantly lower in the hypothyroidism group, and the rate of postoperative anemia which was significantly higher in the hypothyroidism group ( P<0.05). The two groups were followed up 1.0-9.9 years (mean, 6.5 years). At last follow-up, Harris score in both groups were significantly higher than those before operation ( P<0.05). An increase of 39.5±12.3 in hypothyroidism group and 41.3±9.3 in control group were recorded, but no significant difference was found between the two groups ( t=0.958, P=0.340). During the follow-up, 1 case of periprosthetic joint infection occurred in the hypothyroidism group, no loosening or revision was found in the control group.

With the serum TSH controlled within 0.5-3.0 mU/L and T ₄ at normal level preoperatively, as well as the application of multiple blood management, hypothyroid patients can safely go through THA perioperative period and effectively improve joint function, quality of life, and obtain good mid-term effectiveness.