Combining therapeutic laser and herbal remedy for treating ligament injury: an ultrastructural morphological study.

OBJECTIVE: We examined the ultrastructural morphology (number of collagen fibrils, mean and mass-averaged diameter) of isolated and combined treatments of a therapeutic laser and herbs for medial collateral ligament (MCL) injury in rats. MATERIALS AND METHODS: Twenty-eight rats, divided into seven groups: laser (L), herb (H), laser + herb (LH), laser control (LC), herb control (HC), laser sham (LS) and herb sham (HS), were studied. Right MCL of groups L, H, LH, LC and HC were transected, while that of LS and HS remained intact. Group L received 9 treatment sessions of GaAlAs laser with a dosage of 3.5 Jcm(-2); group H received herbal plaster treatment; groups LH had combined treatments of laser and herb; group LC had placebo laser; group LS had no treatment; groups HC and HS received only bandage without herb. All MCLs were analyzed using transmission electron microscopy at 3 weeks. RESULTS: Differences (p < 0.05) existed in mean fibril diameters among groups. Core mass-averaged diameters of groups L and H were larger than the control groups (LC and HC). Fibril diameter of group LH (combined treatment) was even larger and approaching that of the intact MCL. CONCLUSION: Combined therapeutic laser and herbal treatment hastened collagen fibril maturation in MCL repair.

The combined treatment effects of therapeutic laser and exercise on tendon repair.

OBJECTIVE: In this study we investigated the effects of different intensities of therapeutic laser energy and running exercise, and their combined effects on the repair of Achilles tendons in rats. MATERIALS AND METHODS: Thirty-six mature Sprague-Dawley rats that received surgical hemi-transection of their right Achilles tendon were tested. Three laser dosages (4 J/cm2, 1 J/cm2 and 0 J/cm2) and three running periods (30 min, 15 min, and 0 min) resulting in nine different dosage and time groups were studied with four rats in each group. The treatments were given on alternate days starting on day 5 post-injury. On day 22, the tendons were tested for load-relaxation, stiffness, and ultimate strength. RESULTS: There was a significant effect of laser energy on normalized load-relaxation, the rats receiving 4 J/cm2 had less load-relaxation than those receiving no laser treatment (p = 0.05). Results of stiffness testing revealed a significant effect, and rats that ran for 30 min had more stiffness than those that did not run (p = 0.015). For ultimate strength, due to a significant interaction (p = 0.05), the two factors were analyzed separately, and the results showed that for rats receiving no laser therapy, those that had run for 15 min and 30 min had more strength than those that did not run (p = 0.02 and 0.04, respectively). CONCLUSIONS: Both laser therapy and running were found to hasten Achilles tendon repair In general, the rats that received higher dosages of laser energy (4 J/cm2) and ran for longer periods (30 min) performed better than those that received lower dosages of laser energy and ran for shorter periods.

Effects of low-voltage microamperage stimulation on tendon healing in rats.

STUDY DESIGN: Randomized controlled prospective experimental study. OBJECTIVES: To examine the effects of transcutaneous low-voltage microamperage stimulation (LVMAS) on the mechanical strength of Achilles tendon repair in rats at 4 weeks after injury. BACKGROUND: Understanding the effect of LVMAS on the healing of injured tendons is hampered by the lack of related experimental studies, especially from the aspect of biomechanical outcome measures. METHODS AND MEASURES: Fourteen 3-month-old male Sprague-Dawley rats received surgical transection to the medial portion of their right Achilles tendon. The rats were divided into a LVMAS group (n = 7) and control group (n = 7). From day 6 postsurgery onwards, the LVMAS group received daily treatment of transcutaneous LVMAS (2.5 V, 100 microA/cm2, 10 pulses per second, positive current) for a total of 22 sessions, while the control group received placebo LVMAS by the same investigator during that period. On day 31, the Achilles tendons were harvested for biomechanical testing for load relaxation, stiffness, and ultimate tensile strength along the longitudinal direction. RESULTS: The normalized Achilles tendon ultimate tensile strength of the LVMAS group (mean +/- SD, 110.5% +/- 25.0%) was higher than that of the control group (75.3% +/- 20.8%) (P = .014), but no significant difference was found in normalized stiffness and load relaxation between the 2 groups (P = .239 and .350, respectively). CONCLUSION: The results of this study suggest that the administration of transcutaneous LVMAS could improve healing and consequently the tensile strength of partially transected Achilles tendons of rats at 4 weeks after injury.

The effect of therapeutic ultrasound intensity on the ultrastructural morphology of tendon repair.

This study evaluated the effects of ultrasound intensity on the ultrastructural morphology of Achilles tendon healing. Twenty Sprague-Dawley rats with surgically hemi-transected Achilles tendons were randomly assigned into four groups of 0, 0.5, 1.2 and 2 W/cm(2) for ultrasound treatment, with five rats in each group. The treatments were administered with 1 MHz continuous ultrasound daily starting from day 5 after injury. On day 30, ultrathin slides of the Achilles tendons were prepared and examined with transmission electron microscopy. Results showed that the mean collagen fibril size of all treatment groups was higher than the control (p < 0.05). There was no significant difference in the collagen fibril size among the treatment groups. These findings suggest that therapeutic ultrasound can enhance the maturation of collagen fibrils of repairing tendons, and this was not dependent on the intensity of ultrasound applied.

Ultrastructural comparison of medial collateral ligament repair after single or multiple applications of GaAlAs laser in rats.

BACKGROUND AND OBJECTIVES: To examine single versus multiple applications of a gallium aluminum arsenide (GaAlAs) laser on the ultrastructural morphology of surgically injured medial collateral ligaments (MCLs) in rats. STUDY DESIGN/MATERIALS AND METHODS: Sixteen rats were studied with 12 receiving right MCL transection and 4 receiving sham injury. Group 1 (n = 4) received one session of laser (31.6 J/cm(2)) immediately after injury. Group 2 (n = 4) received 9 doses of transcutaneous laser (3.5 J/cm(2)). The controls (Group 3, n = 4) received one session of placebo laser, while the sham Group 4 (n = 4) received no treatment. Ultrastructural analyses were done with electron microscopy at 3 weeks. RESULTS: The mass-averaged diameters of collagen fibril in the core and periphery of MCLs treated with multiple laser were larger than the control and those with single laser treatment (P < 0.05). However, the sham injured group had larger fibrils than all other groups (P < 0.05). CONCLUSIONS: The repairing MCLs had smaller collagen fibrils than the sham injured ligaments. Multiple laser treatments enhanced the collagen growth in the repairing MCLs at 3 weeks after injury, which are superior to a single treatment with similar dosage.

Comparison of single and multiple applications of GaAlAs laser on rat medial collateral ligament repair.

BACKGROUND AND OBJECTIVES: To examine single versus multiple applications of the gallium aluminum arsenide (GaAlAs) laser on the healing of surgically injured medial collateral ligaments (MCLs) in rats. STUDY DESIGN/MATERIALS AND METHODS: Sixteen rats were studied, with 12 receiving surgical transection to their right MCL and 4 receiving a sham injury. Group 1 (n = 4) received a single dose of GaAlAs laser therapy (wavelength 660 nm, average power 8.8 mW, pulse 10 kHz, dosage 31.6 J/cm(2)) directly to their MCL during surgery. Group 2 (n = 4) received 9 doses of GaAlAs laser therapy applied transcutaneously on alternate days (wavelength 660 nm, average power 8.8 mW, pulse 10 kHz, dosage 3.5 J/cm(2)). The controls (Group 3, n = 4) received one session of placebo laser at the time of surgery, with the laser equipment shut down, while the sham injured Group 4 (n = 4) received no treatment. Biomechanical tests for structural stiffness, ultimate tensile strength (UTS), and load-relaxation were done at 3 weeks after injury. The stiffness and UTS data were normalized by expressing as a percentage of the left side of each animal before statistical analysis. RESULTS: The load-relaxation data did not show any differences between the groups (P = 0.18). The normalized stiffness levels of Groups 2 (81.08+/-11.28%) and 4 (92.66+/-13.19%) were significantly higher (P = 0.025) than that of the control Group 3 (58.99+/-15.91%). The normalized UTS of Groups 2 (81.38+/-5.68%) and 4 (90.18+/-8.82%) were also significantly higher (P = 0.012) than that of the control (64.49+/-9.26%). Although, Group 1 had higher mean stiffness and UTS values than the control, no statistically significant difference was found between these two groups. CONCLUSIONS: Multiple laser therapy improves the normalized strength and stiffness of repairing rat MCLs at 3 weeks after injury. The multiple treatments seem to be superior to a single treatment when the cumulative dosages are comparable between the two modes of application.

Effects of a therapeutic laser on the ultrastructural morphology of repairing medial collateral ligament in a rat model.

BACKGROUND AND OBJECTIVES: Low energy laser therapy has been shown to enhance mechanical strength of healing medial collateral ligament (MCL) in rats. The present study investigated its effects on the ultrastructural morphology and collagen fibril profile of healing MCL in rats. STUDY DESIGN/MATERIALS AND METHODS: Thirty-two mature male Sprague-Dawley (SD) rats were used. Twenty-four underwent surgical transection to their right MCLs and eight received only skin wound. Immediately after surgery, eight of the MCL transected rats were treated with a single dose of laser therapy at 63.2 J cm(-2), eight were treated with a single dose of laser therapy at 31.6 J cm(-2), the rest had no treatment and served as control. At 3 and 6 weeks after surgery, the MCLs were harvested and examined with electron microscopy for collagen fibril size, distribution, and alignment. RESULTS: Significant differences (P < 0.001) were found in fibril diameters from the same anatomical site and time period among different groups. The mass-averaged diameters of the laser-treated (64.99-186.29 nm) and sham (64.74-204.34 nm) groups were larger than the control group (58.66-85.89 nm). The collagen fibrils occupied 42.55-59.78, 42.63-53.94, and 36.92-71.64% of the total cross-sectional areas in the laser-treated, control and sham groups, respectively. Mode obliquity was 0.53-0.84 among the three groups. CONCLUSIONS: Single application of low energy laser therapy increases the collagen fibril size of healing MCLs in rats.

Therapeutic low energy laser improves the mechanical strength of repairing medial collateral ligament.

BACKGROUND AND OBJECTIVES: Low energy laser therapy has been shown to enhance collagen production but its effect on tissue strength is not well reported. We tested the effects of therapeutic laser on the strength of healing medial collateral ligaments (MCLs) in rats. STUDY DESIGN/MATERIALS AND METHODS: Twenty-four rats received surgical transection to their right MCL and eight received sham operation. After surgery, 16 received a single dose of gallium aluminum arsenide laser to their transected MCL for 7.5 minutes (n = 8) or 15 minutes (n = 8) and eight served as control with placebo laser, while the sham group didn't receive any treatment. The MCLs were biomechanically tested at either 3 or 6 weeks post-operation. RESULTS: The normalized ultimate tensile strength (UTS) and stiffness of laser and sham groups were larger than control (P < 0.001). The UTS of laser and sham groups were comparable. Laser and sham groups had improved in stiffness from 3 to 6 weeks (P < 0.001). CONCLUSIONS: A single dose of low energy laser therapy improves the UTS and stiffness of repairing MCL at 3 and 6 weeks after injury.