title: Effects of knee immobilization on morphological changes in the semitendinosus muscle-tendon complex after hamstring harvesting for anterior cruciate ligament reconstruction: evaluation using three-dimensional computed tomography.
abstract: BACKGROUND
  It is desirable to maintain the morphology of the semitendinosus muscle-tendon complex after tendon harvesting for anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the effect of knee immobilization on morphological changes in the semitendinosus muscle-tendon complex.
  
  
  METHODS
  In total, 39 patients who underwent ACL reconstruction with autologous semitendinosus tendons were included in this study. After surgery, the knee was immobilized for 3 days in 1 group of patients (group 1; 24 patients; control group) and for a longer period (10-14 days) in the other group (group 2; 15 patients). Three-dimensional computed tomography (3D CT) examination was performed at 6 and/or 12 months after the surgery for all patients. Morphological changes in the semitendinosus muscle-tendon complex (proximal shift of the semitendinosus muscle-tendon junction, width of the regenerated semitendinosus tendons, re-insertion sites of the regenerated tendons, and rate of semitendinosus tendon regeneration) were evaluated.
  
  
  RESULTS
  Successful regeneration of the semitendinosus tendon was confirmed in all patients in group 2. In group 1, 3D CT showed that regeneration of the semitendinosus tendon was unsuccessful in 1 of the 24 patients. The average length of the proximal shift of the semitendinosus muscle-tendon junction was 7.3 ± 2.5 cm in group 1 and 7.2 ± 1.9 cm in group 2. There were no significant differences between the 2 groups with regard to the morphological changes in the semitendinosus muscle-tendon complex.
  
  
  CONCLUSIONS
  This study showed that the structure of regenerated tendons could be clearly identified in 38 of 39 cases (97.4%) after ACL reconstruction. However, prolonged knee immobilization (10-14 days) could not prevent morphological changes in the semitendinosus muscle-tendon complex.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Biomedical Science, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan. nakamae@hiroshima-u.ac.jp
authors.forename: Atsuo
authors.initials: A
authors.lastname: Nakamae
authors.forename: Masataka
authors.initials: M
authors.lastname: Deie
authors.forename: Nobuo
authors.initials: N
authors.lastname: Adachi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nakasa
authors.forename: Makoto
authors.initials: M
authors.lastname: Nishimori
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ochi
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007103:Immobilization / Q000379:methods*; D007718:Knee Injuries / Q000000981:diagnostic imaging / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D018482:Muscle, Skeletal / Q000637:transplantation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013710:Tendons / Q000637:transplantation; D020858:Tissue and Organ Harvesting / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*