J Korean Neurosurg Soc.  2016 Sep;59(5):430-436. 10.3340/jkns.2016.59.5.430.

Chronic Paraspinal Muscle Injury Model in Rat

Affiliations
  • 1Department of Neurosurgery, Hallym University Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
  • 2Department of Neurosurgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea. nspsw@cau.ac.kr

Abstract


OBJECTIVE
The objective of this study is to establish an animal model of chronic paraspinal muscle injury in rat.
METHODS
Fifty four Sprague-Dawley male rats were divided into experimental group (n=30), sham (n=15), and normal group (n=9). Incision was done from T7 to L2 and paraspinal muscles were detached from spine and tied at each level. The paraspinal muscles were exposed and untied at 2 weeks after surgery. Sham operation was done by paraspinal muscles dissection at the same levels and wound closure was done without tying. Kyphotic index and thoracolumbar Cobb's angle were measured at preoperative, 2, 4, 8, and 12 weeks after the first surgery for all groups. The rats were sacrificed at 4, 8, and 12 weeks after the first surgery, and performed histological examinations.
RESULTS
At 4 weeks after surgery, the kyphotic index decreased, but, Cobb's angle increased significantly in the experimental group (p<0.05), and then that were maintained until the end of the experiment. However, there were no significant differences of the kyphotic index and Cobb's angle between sham and normal groups. In histological examinations, necrosis and fibrosis were observed definitely and persisted until 12 weeks after surgery. There were also presences of regenerated muscle cells which nucleus is at the center of cytoplasm, centronucleated myofibers.
CONCLUSION
Our chronic injury model of paraspinal muscles in rats shows necrosis and fibrosis in the muscles for 12 weeks after surgery, which might be useful to study the pathophysiology of the degenerative thoracolumbar kyphosis or degeneration of paraspinal muscles.

Keyword

Animal model; Paraspinal muscle; Chronic injury; Kyphosis; Degeneration

MeSH Terms

Animals
Cytoplasm
Fibrosis
Humans
Kyphosis
Male
Models, Animal
Muscle Cells
Muscles
Necrosis
Paraspinal Muscles*
Rats*
Rats, Sprague-Dawley
Spine
Wounds and Injuries

Figure

  • Fig. 1 Incision was done from T7 to L2. Paraspinal muscles were detached from the spinous processes, facet joints and transverse processes (A). The Fig. of confirming the paraspinal muscles though Adson forcep (B). Tied both muscles eight respectively at each intervertebral level with black silk 4-0 (Ethicon) (C). Two weeks after the surgery, paraspinal muscle exposed (D) and untied.

  • Fig. 2 Representative lateral radiographs of an experimental rat model with C-arm. Preoperative image (A) and the image after 12 weeks of the surgery (B). The kyphotic deformity at 12 weeks after the surgery increased compared to preopearive image.

  • Fig. 3 Kyphotic index was calculated as the ratio of length to depth of the thoracodorsal kyphosis (length/depth). Length was measured as the linear distance from the ventral surface of the vertebral bodies of C7 to L6. Depth was measured as the maximum perpendicular distance from that line to the dorsal vertebral border.

  • Fig. 4 Kyphotic index decreased significantly at 2 weeks after surgery comparing to preoperative index, and at 4 weeks after surgery comparing to the index at 2 weeks after surgery. All the kyphotic indices of experimental group at 2, 4, 8, and 12 weeks after surgery were smaller significantly comparing to those of sham and normal groups at the corresponding time points. *Significant difference between the experimental and sham groups (p<0.05), †Significant difference in experimental group between preoperative and POD#2 week (p<0.05), ‡Significant difference in experimental group between POD#2 week and POD#4 week (p<0.05). POD : post-operative day.

  • Fig. 5 Cobb's angle increased significantly at 2 weeks comparing to preoperative index, and the angle also increased significantly at 4 weeks comparing to that of 2 weeks. There was no significant change in the angles between 4 and 12 weeks after surgery. All the Cobb's angles of experimental group at 2, 4, 8, and 12 weeks after surgery were greater significantly comparing to the corresponding angles of sham and normal groups. *Significant difference between the experimental and sham groups (p<0.05), †Significant difference in experimental group between preoperative and POD#2 week (p<0.05), ‡Significant difference in experimental group between POD#2 week and POD#4 week (p<0.05). POD : post-operative day.

  • Fig. 6 The distribution of muscle fibers in the sham group is regular. Hematoxylin and eosin (H&E), ×100 (A), Picrosirius red, ×100 (B).

  • Fig. 7 In the experimental group at four weeks after the surgery, the fibers with necrosis (*) and inflammatory cells infiltrations are visible [hematoxylin and eosin (H&E), ×100, A]. Connective tissue proliferation and segmental fibrosis are observed (Picrosirius red, ×100, B).

  • Fig. 8 In the experimental group at eight weeks after the surgery, inflammatory cells and necrotic fibers are decreased and connective tissue proliferation and segmental fibrosis are increased by comparison with findings at four weeks after the surgery. The forms of the muscle fibers are irregular and the centronucleated myofibers (arrow) are observed [A : Hematoxylin and eosin (H&E), ×100; B : Picrosirius red ×100; C : Picrosirius red ×400]. In the experimental group at twelve weeks after the surgery, similar findings are observed (D : H&E, ×100; E : Picrosirius red ×100; F : Picrosirius red ×400).


Reference

1. Ball JM, Cagle P, Johnson BE, Lucasey C, Lukert BP. Spinal extension exercises prevent natural progression of kyphosis. Osteoporos Int. 2009; 20:481–489. PMID: 18661090.
Article
2. Booth KC, Bridwell KH, Lenke LG, Baldus CR, Blanke KM. Complications and predictive factors for the successful treatment of flatback deformity (fixed sagittal imbalance). Spine (Phila Pa 1976). 1999; 24:1712–1720. PMID: 10472106.
Article
3. Brereton D, Plochocki J, An D, Costas J, Simons E. The effects of glucocorticoid and voluntary exercise treatment on the development of thoracolumbar kyphosis in dystrophin-deficient mice. PLoS Curr. 2012; 4:e4ffdff160de8b.
Article
4. Bridwell KH, Lenke LG, Lewis SJ. Treatment of spinal stenosis and fixed sagittal imbalance. Clin Orthop Relat Res. 2001; (384):35–44. PMID: 11249178.
Article
5. Cabukoglu C, Güven O, Yildirim Y, Kara H, Ramadan SS. Effect of sagittal plane deformity of the lumbar spine on epidural fibrosis formation after laminectomy : an experimental study in the rat. Spine (Phila Pa 1976). 2004; 2242–2247. PMID: 15480135.
6. Cho KJ, Kim KT, Kim WJ, Lee SH, Jung JH, Kim YT, et al. Pedicle subtraction osteotomy in elderly patients with degenerative sagittal imbalance. Spine (Phila Pa 1976). 2013; 38:E1561–E1566. PMID: 23921326.
Article
7. Coleman R. Picrosirius red staining revisited. Acta Histochem. 2011; 113:231–233. PMID: 20188402.
Article
8. Granito RN, Aveiro MC, Renno AC, Oishi J, Driusso P. Comparison of thoracic kyphosis degree, trunk muscle strength and joint position sense among healthy and osteoporotic elderly women : a cross-sectional preliminary study. Arch Gerontol Geriatr. 2012; 54:e199–e202. PMID: 21831460.
9. Gutiérrez JM, Ownby CL. Skeletal muscle degeneration induced by venom phospholipases A2 : insights into the mechanisms of local and systemic myotoxicity. Toxicon. 2003; 42:915–931. PMID: 15019491.
Article
10. Huynh AM, Aubin CE, Mathieu PA, Labelle H. Simulation of progressive spinal deformities in Duchenne muscular dystrophy using a biomechanical model integrating muscles and vertebral growth modulation. Clin Biomech (Bristol, Avon). 2007; 22:392–399.
Article
11. Hyun SJ, Rhim SC. Clinical outcomes and complications after pedicle subtraction osteotomy for fixed sagittal imbalance patients : a long-term follow-up data. J Korean Neurosurg Soc. 2010; 47:95–101. PMID: 20224706.
Article
12. Kang CH, Shin MJ, Kim SM, Lee SH, Lee CS. MRI of paraspinal muscles in lumbar degenerative kyphosis patients and control patients with chronic low back pain. Clin Radiol. 2007; 62:479–486. PMID: 17398274.
Article
13. Kim WJ, Kang JW, Kang SI, Sung HI, Park KY, Park JG, et al. Factors affecting clinical results after corrective osteotomy for lumbar degenerative kyphosis. Asian Spine J. 2010; 4:7–14. PMID: 20622949.
Article
14. Lattouf R, Younes R, Lutomski D, Naaman N, Godeau G, Senni K, et al. Picrosirius red staining : a useful tool to appraise collagen networks in normal and pathological tissues. J Histochem Cytochem. 2014; 62:751–758. PMID: 25023614.
15. Laws N, Cornford-Nairn RA, Irwin N, Johnsen R, Fletcher S, Wilton SD, et al. Long-term administration of antisense oligonucleotides into the paraspinal muscles of mdx mice reduces kyphosis. J Appl Physiol (1985). 2008; 105:662–668. PMID: 18499783.
Article
16. Laws N, Hoey A. Progression of kyphosis in mdx mice. J Appl Physiol (1985). 2004; 97:1970–1977. PMID: 15234960.
17. McNeill Ingham SJ, de Castro Pochini A, Oliveira DA, Garcia Lisboa BC, Beutel A, Valero-Lapchik VB, et al. Bupivacaine injection leads to muscle force reduction and histologic changes in a murine model. PM R. 2011; 3:1106–1109. PMID: 21974904.
Article
18. Modi HN, Suh SW, Hong JY, Yang JH. Posterior multilevel vertebral osteotomy for severe and rigid idiopathic and nonidiopathic kyphoscoliosis : a further experience with minimum two-year follow-up. Spine (Phila Pa 1976). 2011; 36:1146–1153. PMID: 20948461.
Article
19. Narita S, Yorifuji H. Centrally nucleated fibers (CNFs) compensate the fragility of myofibers in mdx mouse. Neuroreport. 1999; 10:3233–3235. PMID: 10574566.
Article
20. Plant DR, Colarossi FE, Lynch GS. Notexin causes greater myotoxic damage and slower functional repair in mouse skeletal muscles than bupivacaine. Muscle Nerve. 2006; 34:577–585. PMID: 16881061.
Article
21. Sanderson RA, Foley RK, McIvor GW, Kirkaldy-Willis WH. Histological response on skeletal muscle to ischemia. Clin Orthop Relat Res. 1975; (113):27–35. PMID: 811419.
Article
22. Takemitsu Y, Harada Y, Iwahara T, Miyamoto M, Miyatake Y. Lumbar degenerative kyphosis. Clinical, radiological and epidemiological studies. Spine (Phila Pa 1976). 1988; 13:1317–1326. PMID: 2974629.
23. Werneck LC, Cousseau VA, Graells XS, Werneck MC, Scola RH. Muscle study in experimental scoliosis in rabbits with costotransversectomy : evidence of ischemic process. Eur Spine J. 2008; 17:726–733. PMID: 18210168.
Article
24. Wiggins GC, Ondra SL, Shaffrey CI. Management of iatrogenic flatback syndrome. Neurosurg Focus. 2003; 15:E8. PMID: 15347226.
Article
25. Zoabli G, Mathieu PA, Aubin CE. Magnetic resonance imaging of the erector spinae muscles in Duchenne muscular dystrophy : implication for scoliotic deformities. Scoliosis. 2008; 3:21. PMID: 19114022.
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