title: Hypocalcaemia After Total Knee Arthroplasty and its Clinical Significance.
abstract: BACKGROUND
  Transient hypocalcaemia is a frequent complication after total knee arthroplasty (TKA). In this study, we investigated the factors associated with the development of hypocalcaemia after TKA in order to explore its clinical significance and treatment.
  
  
  METHODS
  A retrospective analysis of the change of serum calcium levels for 40 patients after TKA was performed. We investigated the patients prospectively for age, gender, and amount of bleeding at operation. At 24 hours following the operation, serum calcium of the patients was evaluated and a t-test was performed to analyze the categorical variables. Pearson's correlation analysis was used to determine the risk of hypocalcaemia in univariate analysis.
  
  
  RESULTS
  After TKA, the serum calcium level was significantly lower than that before the operation (p<0.01); the incidence of postoperative hypocalcaemia was 77.5%, the decline was positively correlated with intraoperative blood loss (Pearson's r=0.405, p=0.01).
  
  
  CONCLUSIONS
  Hypocalcaemia occurs frequently after TKA, however, clinical symptoms associated with hypocalcaemia are rare. The calcium ion is an important electrolyte, neurotransmitter and blood coagulation factor. It is suggested that we should routinely monitor calcium ion levels during the perioperative period and deal with hypocalcaemia in a timely fashion.
authors.affiliation: Department of Joint Surgery, YanTai Yuhuangding Hospital, Medical College, Qingdao University, Yantai, Shandong Province, P.R. China.
authors.forename: Pengzhou
authors.initials: P
authors.lastname: Gai
authors.affiliation: Department of Joint Surgery, YanTai Yuhuangding Hospital, Medical College, Qingdao University, Yantai, Shandong Province, P.R. China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Sun
authors.affiliation: Department of Joint Surgery, YanTai Yuhuangding Hospital, Medical College, Qingdao University, Yantai, Shandong Province, P.R. China.
authors.forename: Laijian
authors.initials: L
authors.lastname: Sui
authors.affiliation: Department of Joint Surgery, YanTai Yuhuangding Hospital, Medical College, Qingdao University, Yantai, Shandong Province, P.R. China wgdsh123@sohu.com.
authors.forename: Guangda
authors.initials: G
authors.lastname: Wang
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods; D016063:Blood Loss, Surgical / Q000503:physiopathology; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000097:blood* / Q000209:etiology*; D008297:Male; D059035:Perioperative Period / Q000379:methods; D011183:Postoperative Complications / Q000097:blood* / Q000209:etiology*; D011184:Postoperative Period; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D002118:Calcium
keywords: Hypocalcaemia; total knee arthroplasty