title: Compensation by nonoperated joints in the lower limbs during walking after endoprosthetic knee replacement following bone tumor resection.
abstract: BACKGROUND
  Endoprosthetic knee replacement is often used to preserve joint function in patients with bone tumors of the distal femur or proximal tibia. Recently, because of improved oncologic outcome, surgeons are focusing more on the functional outcome of patients with musculoskeletal tumors. We hypothesized that patients who have undergone endoprosthetic knee replacement are forced to compensate for deficiency in their operated joint during walking. In this study, we investigated differences in gait kinematics, kinetics, and energetics between patients with endoprosthetic knee replacement and healthy subjects.
  
  
  METHODS
  We performed gait analysis for 8 patients who underwent endoprosthetic knee replacement after bone tumor resection and 8 matched healthy subjects. Gait kinematics, kinetics, and energetics of patients' ipsilateral and contralateral limbs were compared with those of healthy subjects by using Dunnett's test.
  
  
  RESULTS
  Compared with healthy subjects, patients showed increased negative joint power around the ipsilateral ankle, greater second peak in the contralateral vertical ground reaction forces, and abnormal hip movement on both sides after initial contact.
  
  
  CONCLUSIONS
  Patients tended to compensate for dysfunction of the reconstructed knee by muscles around the ipsilateral ankle and contralateral hip, with increased load on the contralateral limb during walking. These differences could lead to secondary impairments. Further analysis, including musculoskeletal simulation and assessment of long-term functional outcome with regard to secondary musculoskeletal impairment, is needed to verify the significance of the change in gait and to determine the need for special care for secondary musculoskeletal dysfunction in these patients.
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Japan Society for the Promotion of Science, Tokyo, Japan. Electronic address: okita.yuusuke.54a@st.kyoto-u.ac.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Okita
authors.forename: Noriatsu
authors.initials: N
authors.lastname: Tatematsu
authors.forename: Koutatsu
authors.initials: K
authors.lastname: Nagai
authors.forename: Tomitaka
authors.initials: T
authors.lastname: Nakayama
authors.forename: Takeharu
authors.initials: T
authors.lastname: Nakamata
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okamoto
authors.forename: Junya
authors.initials: J
authors.lastname: Toguchida
authors.forename: Shuichi
authors.initials: S
authors.lastname: Matsuda
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ichihashi
authors.forename: Tadao
authors.initials: T
authors.lastname: Tsuboyama
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000843:Ankle Joint / Q000503:physiopathology; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects; D001696:Biomechanical Phenomena; D001859:Bone Neoplasms / Q000601:surgery; D003430:Cross-Sectional Studies; D005260:Female; D005266:Femoral Neoplasms / Q000601:surgery*; D005684:Gait / Q000502:physiology*; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000503:physiopathology*; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D013977:Tibia / Q000601:surgery*; D016896:Treatment Outcome; D016138:Walking; D055815:Young Adult
keywords: Bone tumor; Gait; Knee endoprosthesis