Promotion of medial collateral ligament healing using a high-voltage electrical field

The Effect of Electroacupuncture on Tendon Repair in a Rat Achilles Tendon Rupture Model

Objective

To examine the effect of electroacupuncture (EA) on early post-rupture tendon repair in a rat model of Achilles tendon rupture using histological and mechanical evaluation.

Methods

An Achilles tendon rupture model was prepared in 90 Wistar rats, which were randomly assigned to EA, manual acupuncture or control groups. Rats in the EA group received EA (pulse width 5 ms; stimulation frequency 50 Hz; stimulation strength 20 μA; stimulation time 20 min) daily from 1 day following model preparation until the day of assessment (either 7 or 10 days after model preparation), when the region of interest was sampled to assess tendon repair using in vitro methods. Total cell count and the number of cells staining positive for transforming growth factor-β1 (TGF-β1) and basic fibroblast growth factor (b-FGF) were measured. Tension tests were performed 10 days after model preparation to measure the maximum breaking strength of the repaired tendon.

Results

Both the total cell count and the number of cells positive for b-FGF were significantly higher in the EA group (p<0.05). In the EA group only, immunostaining showed strong expression of TGF-β1 7 days after model preparation (p<0.05). Maximum breaking strength of the repaired tendon 10 days after model preparation was significantly higher in the EA group (p<0.01).

Conclusions

The marked increase in cell count and growth factor expression as well as increased tendon strength in the EA group suggest that EA may be a useful method for promoting tendon repair.

Effect of electroacupuncture stimulation on long-term recovery following Achilles tendon rupture in a rat model

AIMS

In this study we examined the effect of electroacupuncture (EA) stimulation on the mechanical strength of the rat Achilles tendon after long-term recovery.

METHODS

Using 20 rats, an Achilles tendon rupture model was created in an invasive manner. The rats were assigned to one of three groups, that received EA treatment (EA group), minimal acupuncture (MA group) or remained untreated (Control group). In the EA group, EA stimulation (5 ms, 50 Hz, 20 µA, 20 min) was applied to the rupture region over a period of 90 days (five times/week). In the MA group, needles were inserted into the same positions as in the EA group but no electrical current was applied. After 90 days the tendon was measured to calculate the cross-sectional area of the rupture region. Then, the mechanical strength of the tendon was measured by tensile testing.

RESULTS

No significant differences were observed between the three groups in cross-sectional area of the injured tendon. For maximum breaking strength, the EA group showed a significantly higher threshold compared with the Control group (P<0.05) but not the MA group (P=0.24). No significant difference was seen between the MA group and the Control group (P=0.96).

CONCLUSION

Given the EA group showed a significant increase in maximum breaking strength, it is likely that EA stimulation increases the mechanical strength of a repaired tendon after long-term recovery, and EA stimulation could be useful for preventing re-rupture.