Article
Singh et al., (2017)1 Effects of Topical Icing on Inflammation, Angiogenesis, Revascularization, and Myofiber Regeneration in Skeletal Muscle Following Contusion Injury1
Cryotherapy for Contusions
Study Question
Does icing vs a sham treatment effect contusion recovery in rats?
Methods
Study Design
| Item | Control group (sham) | Experimental group (ice) |
|---|---|---|
| n | 40 | 40 |
| Population | Rats | Rats |
| Intervention | Room temp + Figure 8 massage | 20 min Ice + Figure 8 massage |
Dependent Variable
- Groups of 10 rats were then euthanized at day 1, 3, 7, 28 days
- Muscle biopsies were taken from biceps femoris mm to assess:
Results
Necrosis Results
By day 3, the sham group displayed less necrosis and more macrophages (a more advanced stage of healing) compared to the experimental (ice) group, but displayed no difference by day 7.
| Day | Control | Experimental |
|---|---|---|
| Day 1 | Present | Present |
| Day 3 | Nearly cleared necrosis with macrophage presence | Several necrotic areas with less macrophage presence |
| Day 7 | Necrosis cleared, immature muscle fibers | Necrosis cleared, immature muscle fibers |
| Day 28 | Normal tissue structure almost restored, inflammatory cell influx mostly resolved | Normal tissue structure almost restored, inflammatory cell influx mostly resolved |
Neutrophil results
Neutrophils are pathogen fighting immune cells which arerecruited to sites of infection and function to recognize and phagocytose microbes, and kill pathogens through cytotoxic mechanisms2.
By day 1, the control group had more neutrophils than the ice group, indicating healing had begun earlier in the control group than the experimental group1. By day 3, the control group had less neutrophils than the experimental group, which indicates that the control group had moved onto a more advanced stage of healing and was beginning to reuptake neutrophils. By day 7, both groups had no neutrophils, indicating they were both in advanced stages of healing.
| Day | Control | Experimental |
|---|---|---|
| Day 1 | More | Less |
| Day 3 | Less | More |
| Day 7 | None | None |
| Day 28 | None | None |
Macrophage results
Macrophage count was higher in the control group in day 1 and 3, but was then less abundant in the control group in day 7 and 281. This indicates that the control group passed through the phases of healing faster than the experimental (ice) group.
| Day | Control | Experimental |
|---|---|---|
| Day 1 | More | Less |
| Day 3 | More | Less |
| Day 7 | Less | More |
| Day 28 | Less | More |
CD34 Expression results
CD34 expression is a measure of capillary density.
Singh et al., found that by day 3 and 7, the control group had a greater percent of CD34 stained area in muscle1. By day 28, the icing group had a greater percent of CD34 than the sham group1.
Von Willebrand Factor (vWF) Results
vWF (indicates endothelial cell damage): percent of vWF stained area was greater in muscle from the sham group than icing at day 3 and 7 post injury.
Vascular endothelial growth factor (VEGF) Results
Vascular endothelial growth factor (VEGF) was used in this study as a marker of angiogenesis (new blood vessels)1
Singh (2017) found that the percent of VEGF stained area in muscle was greater in the control group compared to the experimental (ice) group at 3 days post injury1. Indicating that healing occurred earlier in the control group.
Nestin results
Singh (2017) used Nestin count as a measure of of maturing endothelial cells1. Singh et al.1 found that the area of nestin in the muscle was greater in the control group than the experimental (ice) group by day 3 post injury1. By day 7 the experimental (ice) group had a greater amount of nestin in the muscle, indicating that the control group had progressed into the next stage of healing before the exerpimental group1.
Vessel volume results
Micro-CT was used to measure vessel volume in mm By day 3, the control group had greater vessel volume compared to the experimental (ice) group1. No difference between groups by day 281.
Capillary density results
Number of capillaries per fiber and the number of capillaries per mm^2 at 28 day post injury did not differ between groups1.
Skeletal myofiber regeneration results
Day 7: centrally nucleated regenerating mm fibers present in sham, only a few in icing group Percentage of regenerating fibers relative to number of fibers was greater in the icing group than in sham 28 d post injury and no difference at 7 days.
Results Overview
Compared to the control group, Icing attenuated and/or delayed neutrophil and macrophage infiltration, expression of vWF, VEGF and nestin, and change in vessel volume within muscle 7 days after injury. Icing did not influence capillary density in mm 28 days post injury1. The percentage of immature myofibers relative to the total number of fibers was greater in the icing group than sham 28 d after injury. Myofiber CSA did not differ between groups after 7 or 28 days1.
Study Limitations
Conclusion
Icing may mildly suppress/disrupt inflammation, angiogenesis, and revascularization within the first few days. These effects do not stop or slow muscle regeneration/capillary density after contusion injury1.
Clinical Significance
Icing does not seem to improve or be beneficial to the healing process post-contusion, however if a patient enjoys icing, it will not slow or stop muscle regeneration.
References
1.
Singh DP, Barani Lonbani Z, Woodruff MA, Parker TJ, Steck R, Peake JM. Effects of Topical Icing on Inflammation, Angiogenesis, Revascularization, and Myofiber Regeneration in Skeletal Muscle Following Contusion Injury. Frontiers in Physiology. 2017;8. doi:10.3389/fphys.2017.00093
2.
Mayadas TN, Cullere X, Lowell CA. The Multifaceted Functions of Neutrophils. Annual Review of Pathology: Mechanisms of Disease. 2014;9(1):181-218. doi:10.1146/annurev-pathol-020712-164023
Citation
For attribution, please cite this work as:
Yomogida N, Kerstein C. Cryotherapy for
Contusions. Published January 20, 2024. https://yomokerst.com/Journal
club/jc1_cryotherapy_contusions.html