title: A prospective randomised study of minimally invasive midvastus total knee arthroplasty compared with standard total knee arthroplasty.
abstract: BACKGROUND
  Proposed advantages of minimally invasive surgery include shorter hospital stay, less blood loss, and a greater range of motion but potential concerns are raised about both prolonged learning curves and a compromise in exposure leading to implant malposition.
  
  
  METHODS
  This powered study evaluates the outcomes of 80 patients randomised to have mini-midvastus (MMV) approach or standard medial parapatellar (MPP) approach. Rehabilitation protocols and discharge criteria were standardised. Patients were discharged home directly, capable of safe independent care. Validated outcome measures were recorded post-operatively at intervals up to 1 year. Independent, blinded review of post-operative x-rays was obtained.
  
  
  RESULTS
  Length of stay was similar in the MMV and MPP groups (median 3.73 days vs. 3.75 days). No statistically significant differences were detected in either the demographic data or any intra-operative variable apart from blood loss and incision length. No statistically significant difference in clinical outcome measures (Oxford/Knee Society Scores) or radiographic analysis was observed.
  
  
  CONCLUSIONS
  The MMV approach does not appear to confer any clinically significant benefit apart from a smaller surgical scar, compared to the MPP surgical technique. Level of evidence I: randomised control trial. R.E.C. 040301.
authors.affiliation: Department of Orthopaedic Surgery, Bradford Teaching Hospitals NHS Foundation Trust, Duckworth Lane, Bradford, BD9 6RJ, United Kingdom. stephen.guy@bthft.nhs.uk
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Guy
authors.forename: Mark A
authors.initials: MA
authors.lastname: Farndon
authors.forename: Jonathon L
authors.initials: JL
authors.lastname: Conroy
authors.forename: Caroline
authors.initials: C
authors.lastname: Bennett
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Grainger
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: London
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D011859:Radiography; D016059:Range of Motion, Articular; D020127:Recovery of Function; D016896:Treatment Outcome