title: Gait analysis before and after corrective osteotomy in patients with knee osteoarthritis and a valgus deformity.
abstract: OBJECTIVE
  In this prospective study, the changes in kinetics and kinematics of gait and clinical outcomes after a varus osteotomy (tibial, femoral or double osteotomy) in patients with osteoarthritis (OA) of the knee and a valgus leg alignment were analysed and compared to healthy subjects.
  
  
  METHODS
  Twelve patients and ten healthy controls were included. Both kinetics and kinematics of gait and clinical and radiographic outcomes were evaluated.
  
  
  RESULTS
  The knee adduction moment increased significantly postoperatively (p < 0.05) and almost similar to the control group. Patients showed less knee and hip flexion/extension motion and moment during gait pre- and postoperatively compared to the controls. A significant improvement was found in WOMAC [80.8 (SD 16.1), p = 0.000], KOS [74.9 (SD 14.7), p = 0.018], OKS [21.2 (SD 7.5), p = 0.000] and VAS-pain [32.9 (SD 20.9), p = 0.003] in all patients irrespective of the osteotomy technique used. The radiographic measurements showed a mean hip knee ankle (HKA) angle correction of 10.4° (95 % CI 6.4°-14.4°).
  
  
  CONCLUSIONS
  In patients with knee OA combined with a valgus leg alignment, the varus-producing osteotomy is a successful treatment. Postoperatively, the patients showed kinetics and kinematics of gait similar as that of a healthy control group. A significant increase in the knee adduction moment during stance phase was found, which was related to the degree of correction. The HKA angle towards zero degrees caused a medial shift in the dynamic knee loading. The medial shift will optimally restore cartilage loading forces and knee ligament balance and reduces progression of OA or the risk of OA. A significant improvement in all clinical outcomes was also found.
  
  
  METHODS
  III.
authors.affiliation: Department of Orthopaedics, Radboud University Medical Centre, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands. nienkevanegmond@hotmail.com.
authors.forename: N
authors.initials: N
authors.lastname: van Egmond
authors.affiliation: Institute of Health Studies, HAN University, Kapittelweg 33, 6525, EN, Nijmegen, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Stolwijk
authors.affiliation: Department of Orthopaedics, Sint Maartenskliniek, P.O. Box 9011, 6500, GM, Nijmegen, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: van Heerwaarden
authors.affiliation: Department of Orthopaedics, Radboud University Medical Centre, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: van Kampen
authors.affiliation: Research Department, Sint Maartenskliniek, P.O. Box 9011, 6500, GM, Nijmegen, The Netherlands.
authors.forename: N L W
authors.initials: NLW
authors.lastname: Keijsers
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D017760:Bone Malalignment / Q000503:physiopathology / Q000601:surgery*; D016022:Case-Control Studies; D005260:Female; D005269:Femur / Q000503:physiopathology / Q000601:surgery*; D005684:Gait / Q000502:physiology*; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery*; D010027:Osteotomy; D011446:Prospective Studies; D013977:Tibia / Q000503:physiopathology / Q000601:surgery*
keywords: Closed wedge medial high tibial osteotomy; Double osteotomy; Gait analysis; Supracondylar femoral osteotomy; Valgus alignment