Gilotra Mohit N, Shorofsky Michael J, Stein Jason A, Murthi Anand M
Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
Department of Orthopaedics and Sports Medicine, MedStar Union Memorial Hospital, Baltimore, MD, 21218, USA.
BMC Musculoskelet Disord. 2016 Mar 15;17:127. doi: 10.1186/s12891-016-0978-y.
We evaluated effects of botulinum toxin A (Botox) and cast immobilization on tendon healing in a rat model. Injection of Botox into rat supraspinatus was hypothesized to reduce muscle active force and improved healing.
Eighty-four supraspinatus tendons were surgically transected and repaired in 42 Sprague-Dawley rats (transosseous technique). After repair, supraspinatus muscle was injected with saline or Botox (3 or 6 U/kg). Half the shoulders were cast-immobilized for the entire postoperative period; half were allowed free cage activity. Histology was examined at 2, 4, 8, and 12 weeks. A healing zone cross-sectional area was measured, and biomechanical testing of repair strength and tendon viscoelastic properties was conducted at 4 and 12 weeks.
Botox alone and cast immobilization alone exhibited increased ultimate load compared with controls (saline injection, no immobilization) at 4 weeks. No difference in ultimate load occurred between Botox-only and cast-only groups. At 12 weeks, the Botox (6 U/kg) plus cast immobilization group was significantly weakest (p < 0.05). A trend was shown toward decreased healing zone cross-sectional areas in casted groups.
Supraspinatus Botox injection after rotator cuff repair might help protect the repair. However, cast immobilization plus Botox administration is harmful to rotator cuff healing in a rat tendon model.
我们在大鼠模型中评估了A型肉毒杆菌毒素（保妥适）和石膏固定对肌腱愈合的影响。将保妥适注射到大鼠冈上肌中被认为可以降低肌肉主动力并促进愈合。
对42只Sprague-Dawley大鼠（采用经骨技术）的84条冈上肌腱进行手术切断并修复。修复后，向冈上肌注射生理盐水或保妥适（3或6 U/kg）。术后一半的肩部用石膏固定；另一半允许在笼内自由活动。在术后2、4、8和12周进行组织学检查。测量愈合区横截面积，并在4周和12周时对修复强度和肌腱粘弹性进行生物力学测试。
在4周时，单独使用保妥适和单独使用石膏固定的最终负荷均高于对照组（注射生理盐水，未固定）。仅使用保妥适组和仅使用石膏组之间的最终负荷没有差异。在12周时，保妥适（6 U/kg）加石膏固定组明显最弱（p < 0.05）。石膏固定组的愈合区横截面积有减小的趋势。
肩袖修复后注射冈上肌保妥适可能有助于保护修复。然而，在大鼠肌腱模型中，石膏固定加保妥适给药对肩袖愈合有害。
