title: Minimally invasive surgery did not improve outcome compared to conventional surgery following unicompartmental knee arthroplasty using local infiltration analgesia: a randomized controlled trial with 40 patients.
abstract: OBJECTIVE
  There has recently been interest in the advantages of minimally invasive surgery (MIS) over conventional surgery, and on local infiltration analgesia (LIA) during knee arthroplasty. In this randomized controlled trial, we investigated whether MIS would result in earlier home-readiness and reduced postoperative pain compared to conventional unicompartmental knee arthroplasty (UKA) where both groups received LIA.
  
  
  METHODS
  40 patients scheduled for UKA were randomized to a MIS group or a conventional surgery (CON) group. Both groups received LIA with a mixture of ropivacaine, ketorolac, and epinephrine given intra- and postoperatively. The primary endpoint was home-readiness (time to fulfillment of discharge criteria). The patients were followed for 6 months.
  
  
  RESULTS
  We found no statistically significant difference in home-readiness between the MIS group (median (range) 24 (21-71) hours) and the CON group (24 (21-46) hours). No statistically significant differences between the groups were found in the secondary endpoints pain intensity, morphine consumption, knee function, hospital stay, patient satisfaction, Oxford knee score, and EQ-5D. The side effects were also similar in the two groups, except for a higher incidence of nausea on the second postoperative day in the MIS group.
  
  
  CONCLUSIONS
  Minimally invasive surgery did not improve outcome after unicompartmental knee arthroplasty compared to conventional surgery, when both groups received local infiltration analgesia. The surgical approach (MIS or conventional surgery) should be selected according to the surgeon's preferences and local hospital policies. ClinicalTrials.gov. (Identifier NCT00991445).
authors.affiliation: Departments of Orthopedic Surgery, Institution for Clinical Medicine, University Hospital, School of Health and Medical Sciences, Örebro University, Örebro, Sweden. per.essving@orebroll.se
authors.forename: Per
authors.initials: P
authors.lastname: Essving
authors.forename: Kjell
authors.initials: K
authors.lastname: Axelsson
authors.forename: Lena
authors.initials: L
authors.lastname: Otterborg
authors.forename: Henrik
authors.initials: H
authors.lastname: Spännar
authors.forename: Anil
authors.initials: A
authors.lastname: Gupta
authors.forename: Anders
authors.initials: A
authors.lastname: Magnuson
authors.forename: Anders
authors.initials: A
authors.lastname: Lundin
mesh_terms: D000328:Adult; D000368:Aged; D000698:Analgesia / Q000379:methods; D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000008:administration & dosage*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007270:Injections, Intra-Articular / Q000379:methods; D007720:Knee Prosthesis; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects / Q000379:methods; D010147:Pain Measurement; D010149:Postoperative Pain / Q000503:physiopathology; D018579:Patient Selection; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular / Q000502:physiology; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D025321:Surgery, Computer-Assisted / Q000009:adverse effects / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local