title: Effects of selective paralysis of the supraspinatus muscle using botulinum neurotoxin a in rotator cuff healing in rats.
abstract: We hypothesized that a temporary rotator cuff paralysis using botulinum-neurotoxin A (BoNtA) would lead to an improved tendon-to-bone healing after repair of supraspinatus lesions. One hundred sixty Sprague-Dawley rats were randomly assigned to either the BoNtA or the control (saline) group. BoNtA/saline-solution was injected into the supraspinatus muscle 1 week prior to surgery. A supraspinatus defect was made; we distinguished between a lesion with normal and increased repair load. Furthermore, one subgroup had the operated shoulder immobilized in a cast. Histologic analysis and biomechanical testing followed. Specimens from the BoNtA-group, which were treated with an increased repair load, showed less cellularity and more organization in the interface tissue compared to the saline control group. In addition, we found that the collagen 1-3 quotient in the BoNtA specimen was significantly (p = 0.0051) higher than in the control group. Ultimate load at failure between the groups was not significantly different (p > 0.05). We did not observe any significant differences between the mobilized and immobilized specimen (p = 0.2079). The study shows that tendon-to-bone healing after rotator cuff repair can be altered positively using BoNtA pre-operatively. Tears with increased repair load seem to benefit the most-at least histologically.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Munich (LMU)-Campus Grosshadern, Marchioninistr. 15, 81377 Munich, Germany. andreas.ficklscherer@med.uni-muenchen.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Ficklscherer
authors.forename: Tessa-Katharina
authors.initials: TK
authors.lastname: Hartl
authors.forename: Markus
authors.initials: M
authors.lastname: Scharf
authors.forename: Birte
authors.initials: B
authors.lastname: Sievers
authors.forename: Christian
authors.initials: C
authors.lastname: Schröder
authors.forename: Stefan
authors.initials: S
authors.lastname: Milz
authors.forename: Thomas
authors.initials: T
authors.lastname: Niethammer
authors.forename: Matthias F
authors.initials: MF
authors.lastname: Pietschmann
authors.forename: Peter E
authors.initials: PE
authors.lastname: Müller
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects / Q000502:physiology; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D004195:Disease Models, Animal; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D009133:Muscular Atrophy / Q000139:chemically induced; D009465:Neuromuscular Agents / Q000494:pharmacology; D010243:Paralysis / Q000139:chemically induced*; D011897:Random Allocation; D016059:Range of Motion, Articular / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017006:Rotator Cuff / Q000503:physiopathology; D000070636:Rotator Cuff Injuries; D013708:Tendon Injuries / Q000188:drug therapy* / Q000503:physiopathology; D014945:Wound Healing / Q000187:drug effects* / Q000502:physiology
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A