title: 2013 Neer Award: Effect of the adipose-derived stem cell for the improvement of fatty degeneration and rotator cuff healing in rabbit model.
abstract: BACKGROUND
  This study was conducted to verify the effects of adipose-derived stem cells (ADSCs) on tendon healing and reversal of fatty infiltration in a chronic rotator cuff tear model by using the rabbit subscapularis (SSC).
  
  
  METHODS
  The SSC insertions in 32 rabbits were cut bilaterally. After 6 weeks, secondary procedures were performed bilaterally, dividing the rabbits into 4 groups of 8 rabbits each as follows: the ADSC+repair group, saline+repair group, ADSC-only group, and saline-only group. A fifth group of 8 rabbits served as normal controls (control group). Electromyographic, biomechanical, and histologic analyses were performed 6 weeks after the secondary procedures.
  
  
  RESULTS
  All SSC tendons in the ADSC-only and saline-only groups failed to heal and were excluded from the electromyographic and biomechanical tests. On electromyographic evaluation, the ADSC+repair group exhibited a larger compound muscle action potential area than the saline+repair group (11.86 ± 2.97 ms · mV vs 9.42 ± 3.57 ms · mV, P = .029), and this response was almost at the level of the control group (13.17 ± 6.6 3 ms · mV, P = .456). Biomechanically, the load-to-failure of the ADSC+repair group (87.02 ± 29.81 N) was higher than that of the saline+repair group (59.85 ± 37.77 N), although this difference did not reach statistical significance (P = .085). Histologically, the mean proportions of fatty infiltration in the SSC muscles were 29% ± 15%, 43% ± 9%, 51% ± 14%, 63% ± 10%, and 18% ± 9% for the ADSC+repair, saline+repair, ADSC-only, saline-only, and control groups, respectively (P < .001). The degree of fat staining increased from the ADSC+repair group (unclear or weak) to the saline-only group (strongly present).
  
  
  CONCLUSIONS
  Local administration of ADSCs might have the possibility to improve muscle function and tendon healing and decrease fatty infiltration after cuff repair.
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Joo Han
authors.initials: JH
authors.lastname: Oh
authors.affiliation: Department of Orthopaedic Surgery, Konkuk University School of Medicine, Konkuk University Medical Center, Seoul, South Korea. Electronic address: smilecsw@gmail.com.
authors.forename: Seok Won
authors.initials: SW
authors.lastname: Chung
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, South Korea.
authors.forename: Sae Hoon
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Neurology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, South Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Chung
authors.affiliation: Department of Orthopaedic Surgery, Myongji Hospital, Goyang, South Korea.
authors.forename: Joon Yub
authors.initials: JY
authors.lastname: Kim
mesh_terms: D000273:Adipose Tissue / Q000166:cytology* / Q000473:pathology; D000818:Animals; D001363:Awards and Prizes; D002908:Chronic Disease; D004195:Disease Models, Animal; D008297:Male; D011817:Rabbits; D011897:Random Allocation; D017006:Rotator Cuff / Q000503:physiopathology / Q000601:surgery*; D000070636:Rotator Cuff Injuries; D033581:Stem Cell Transplantation; D013708:Tendon Injuries / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D014945:Wound Healing / Q000502:physiology*
keywords: Adipose-derived stem cell; compound muscle action potential; fatty infiltration; rotator cuff tear; tendon-to-bone healing