title: Better quadriceps recovery after minimally invasive total knee arthroplasty.
abstract: OBJECTIVE
  The proponents of minimally invasive total knee arthroplasty (TKA) have reported better functional recovery than conventional TKA. In most of the previous studies, the results were shown with the relatively subjective methods. We investigated the objective results with a dynamometry in this prospective randomized study. It was hypothesized that minimally invasive TKA would have a better and earlier recovery of quadriceps force in terms of the objective numeric data.
  
  
  METHODS
  Sixty-six TKAs were prospectively randomized into two groups. Thirty-three knees underwent minimally invasive TKA using mini-midvastus approach and 33 knees underwent conventional TKA using medial parapatellar approach. The quadriceps force was assessed using a dynamometer. The data were collected preoperatively and at postoperative 6 weeks, 3 months, 6 months and 1 year consecutively.
  
  
  RESULTS
  The mean of quadriceps force in minimally invasive TKA group at postoperative 6 weeks was greater than conventional TKA after removing the covariate (preoperative quadriceps force) with analysis of covariance (P = 0.002), but thereafter, the difference was not significant till 1 year. Meanwhile, with repeated measures analysis of variance, conventional TKA group had greater quadriceps recovery than minimally invasive TKA group during postoperative 6 weeks to 3 months (P = 0.035). The proportion of patients unable to recover the quadriceps force to their preoperative levels by 1 year postoperatively was similar in two groups.
  
  
  CONCLUSIONS
  Minimally invasive TKA has benefit in quadriceps recovery at earlier rehabilitation period although catch-up recovery in conventional TKA was accelerated from the postoperative 6 weeks to 3 months. It may support the concept of early return to full activity after minimally invasive TKA, and patients might get back early to normal life.
authors.affiliation: Department of Orthopaedic Surgery, Center for Joint Diseases and Trauma, Kyung Hee University Hospital at Gangdong, 892 Dongnam-ro, Gangdong-gu, Seoul, 134-727, Korea.
authors.forename: Kye-Youl
authors.initials: KY
authors.lastname: Cho
authors.forename: Kang-Il
authors.initials: KI
authors.lastname: Kim
authors.forename: Salil
authors.initials: S
authors.lastname: Umrani
authors.forename: Se-Hyun
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D053580:Muscle Strength / Q000502:physiology; D053581:Muscle Strength Dynamometer; D011184:Postoperative Period; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000503:physiopathology* / Q000601:surgery; D020127:Recovery of Function