title: A Single-Dose Intra-Articular Morphine plus Bupivacaine versus Morphine Alone following Knee Arthroscopy: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  The purpose of this study was to compare the efficacy and safety of a single-dose intra-articular morphine plus bupivacaine versus morphine alone in patients undergoing arthroscopic knee surgery.
  
  
  METHODS
  Randomized controlled trials comparing a combination of morphine and bupivacaine with morphine alone injected intra-articularly in the management of pain after knee arthrocopic surgery were retrieved (up to August 10, 2014) from MEDLINE, the Cochrane Library and Embase databases. The weighted mean difference (WMD), relative risk (RR) and their corresponding 95% confidence intervals (CIs) were calculated using RevMan statistical software.
  
  
  RESULTS
  Thirteen randomized controlled trials were included. Statistically significant differences were observed with regard to the VAS values during the immediate period (0-2h) (WMD -1.16; 95% CI -2.01 to -0.31; p = 0.007) and the time to first request for rescue analgesia (WMD = 2.05; 95% CI 0.19 to 3.92; p = 0.03). However, there was no significant difference in the VAS pain score during the early period (2-6h) (WMD -0.36; 95% CI -1.13 to 0.41; p = 0.35), the late period (6-48h) (WMD 0.11; 95% CI -0.40 to 0.63; p = 0.67), and the number of patients requiring supplementary analgesia (RR = 0.78; 95% CI 0.57 to 1.05; p = 0.10). In addition, systematic review showed that intra-articular morphine plus bupivacaine would not increase the incidence of adverse effects compared with morphine alone.
  
  
  CONCLUSIONS
  The present study suggested that the administration of single-dose intra-articular morphine plus bupivacaine provided better pain relief during the immediate period (0-2h), and lengthened the time interval before the first request for analgesic rescue without increasing the short-term side effects when compared with morphine alone.
  
  
  METHODS
  Level I, meta-analysis of Level I studies.
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Dong-Xing
authors.initials: DX
authors.lastname: Xie
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zeng
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Yi-Lun
authors.initials: YL
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Yu-Sheng
authors.initials: YS
authors.lastname: Li
authors.affiliation: Department of epidemiology and health statistics, School of Public Health, Central South University, Changsha, Hunan Province, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wei
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Tuo
authors.initials: T
authors.lastname: Yang
authors.affiliation: Department of epidemiology and health statistics, School of Public Health, Central South University, Changsha, Hunan Province, China.
authors.forename: Tu-Bao
authors.initials: TB
authors.lastname: Yang
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Guang-Hua
authors.initials: GH
authors.lastname: Lei
mesh_terms: D001182:Arthroscopy / Q000009:adverse effects*; D002045:Bupivacaine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D006801:Humans; D007717:Knee / Q000601:surgery*; D007719:Knee Joint; D009020:Morphine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D059408:Pain Management / Q000009:adverse effects / Q000379:methods*
chemical_list: D009020:Morphine; D002045:Bupivacaine