7600 series automatic biochemical analyzer

Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), ALP, gamma‐glutaryltransferase (GGT), total bilirubin (TBIL), direct bilirubin (DBIL) and albumin (ALB) in PBC patients was detected by Hitachi 7600 series automatic biochemical analyzer (Japan).

All blood samples were collected on the day of surgery. The synovial fluid of the knee was collected on the day the blood samples were collected and the synovial fluid of the hip was collected when the capsule was incised intraoperatively. All specimens were submitted for examination within 2 h after collection. To assess CRP levels, plasma and synovial fluid were stored in lithium-heparin vacuum collection tubes. The CRP was tested using a particle-enhanced turbidimetric immunoassay with a HITACHI 7600 Series Automatic Biochemical Analyzer (Hitachi, Tokyo, Japan) and diagnostic kit (DiaSys Diagnostic Systems GmbH, Shanghai, China). Synovial fluid was examined for WBCs and PMNs using a haematology analyzer (Symex XE-5000 haematology analyzer, Symex, Japan), and the synovial fluid was cultured for 14 days on Columbia agar, chocolate agar, and Schaedler agar. At least three suspected tissue specimens were obtained intraoperatively by a stationary surgeon for culture, and the tissue specimens were subjected to intraoperatively frozen section and histopathological examination.

Preoperative blood samples were collected on the morning of the operation to determine the preoperative Ca and PTH levels. The postoperative serum Ca and PTH levels were monitored on the morning of the 1^st (within 24 hours postsurgery), 3^rd, 5^th, and 7^th postoperative days. A low PTH level was defined as a PTH measurement <15 pg/mL within 24 hours of surgery. Patients were discharged on the 3^rd∼7^th day postsurgery and were requested to return for clinical follow-up on the 1^st, 3^rd, 6^th, and 12^th postoperative months. The serum Ca and PTH levels were measured using a Hitachi 7600 series automatic biochemical analyzer (Hitachi, Tokyo, Japan) and electrochemiluminescence system (Roche Diagnostics GmbH, Mannheim, Germany).