title: Low-intensity pulsed ultrasound accelerates maturation of callus in patients treated with opening-wedge high tibial osteotomy by hemicallotasis.
abstract: BACKGROUND
  Opening-wedge high tibial osteotomy by hemicallotasis for osteoarthritis in the medial compartment of the knee requires external fixation for a long time, until callus maturation is complete. The aim of this study was to determine if low-intensity pulsed ultrasound would accelerate callus maturation when applied after distraction to limbs treated with opening-wedge high tibial osteotomy by hemicallotasis.
  
  
  METHODS
  Twenty-one patients with symmetric grades of osteoarthritis and similar degrees of varus deformity in the two knees underwent bilateral one-stage opening-wedge high tibial osteotomy by hemicallotasis. After completion of distraction, the bone mineral density of the distraction callus was measured. Then, one randomly selected limb was subjected to ultrasound treatment for twenty minutes daily until removal of the external fixator. The contralateral limb was left untreated to serve as the control. After four weeks of treatment, bone mineral density was measured again.
  
  
  RESULTS
  During the four-week treatment period, the mean increase in callus bone mineral density was significantly greater in the ultrasound-treated tibiae (0.20 +/- 0.12 g/cm(2)) than in the control tibiae (0.13 +/- 0.10 g/cm(2)) (p = 0.02, unpaired t test). In eighteen patients the increase in the bone mineral density was greater in the ultrasound-treated limb than in the control limb, whereas in three patients the increase was greater in the control limb.
  
  
  CONCLUSIONS
  We found that low-intensity pulsed ultrasound applied during the consolidation phase of distraction osteogenesis accelerates callus maturation after opening-wedge high tibial osteotomy by hemicallotasis in elderly patients.
authors.affiliation: Department of Orthopaedics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan. tsumaki-n@umin.ac.jp
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tsumaki
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kakiuchi
authors.forename: Jiro
authors.initials: J
authors.lastname: Sasaki
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ochi
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015519:Bone Density; D002146:Bony Callus / Q000503:physiopathology*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000378:metabolism / Q000601:surgery*; D010027:Osteotomy; D013977:Tibia / Q000378:metabolism / Q000601:surgery*; D014464:Ultrasonic Therapy; D014945:Wound Healing