The Treatment of Achilles Tendonitis Using Therapeutic Laser
Achilles tendonitis is a commonly occurring painful condition. It affects about 11% of all running injuries. Achilles tendonitis can be quite debilitating, preventing the sufferer from running and causing great difficulty walking, especially when acute. Achilles tendonitis tends to occur more in middle-aged recreational athletes than other age groups. The Achilles tendons, like other body tissues become more rigid, less flexible, and more susceptible to injury as we age. It is usually caused from overuse and associated with over-pronation of the foot or changes in footwear or running routine.
The primary presenting symptom is posterior heel pain. Pain is usually worse when first ambulating following period of inactivity. Diagnosis is made primarily from the symptom history and x-rays are of little value. Palpatory exam will help locate the exact area of involvement (see Figure 1).1
Repeated episodes of Achilles tendon-itis can lead to the development of Achilles tendinosis, a chronic degenerative condition of the tendon that can lead to tendon tearing or rupture which usually requires surgical repair.
Conventional treatment usually consists of RICE self-care (rest, ice packs, compression, and elevation) and non-steroidal anti-inflammatory medication along with stretching and exercises.2
Studies of Tendinopathy Laser Treatment
Therapeutic laser has been shown to produce promising results based on the data obtained from several published research studies.
Tumitty et al3 reviewed twenty-five controlled clinical trials of the treatment of tendinopathy with low level laser therapy. There were twelve positive studies and thirteen inconclusive studies. Effective dosages were apparent in the positive studies and absent in the inconclusive studies. In a lateral epicondylitis study, the laser group demonstrated a 9.59 kg higher grip strength than control and a decrease in visual analogue scale of 13.6 mm. They concluded that thera-peutic laser can potentially be effective in treating tendinopathy when recommended dosages are used.3
Bjordal and Couppe4 performed a randomized controlled clinical trial for tendonitis. They found eight clinical trials that met the selection criteria out of seventy-seven. They, like Tumitty, found that adequate dosage was essential to achieving positive clinical results.
Bjordal and Couppe also conducted a separate review5 of four laboratory trials that investigated optimal doses for collagen inflammation reduction. They found that optimal doses were 38 joules/cm2 with an intensity of 210 mW/cm2. They also reviewed ten laboratory studies that investigated collagen proliferation and identified the optimal dose for stimulation of tendon regeneration as being from 0.24.0 joules/cm2 and 210 mW/cm2 intensity.5
Bjordal et al, in yet another study,6 observed the results of therapeutic laser in seven patients with bilateral Achilles tendonitis (14 tendons) who had aggravated symptoms after pain-inducing activity. A 904 nm GaAs laser was used to deliver 1.8 joules at each of three points along the Achilles tendon. Laser or placebo was applied randomly to each Achilles tendon with both the patients and therapists blinded. Inflammation was examined by minimally-invasive microdialysis for measuring PGE2 in peritendinous tissue, as well as Doppler ultrasound measurement of peri- and intra-tendinous blood flow, pressure algometry, and the single hop test. PGE2 was significantly reduced at 75, 90, and 105 minutes after active laser therapy as compared to the pre-treatment group or placebo group.6
Enwemeka et al7 observed the effects of therapeutic laser on twenty rabbits that had surgical transection and repair. Six rabbits had local treatment with a HeNe laser, seven with a GaAs laser and seven were controls. The tensile strength of the tendons were evaluated after fourteen days. The mean value of the HeNe group was 251, the GaAs group was 233, and the control group was 154.
Reddy et al8 performed a study in which two parameters were observed in tenectomized rabbit Achilles tendons: early mechanical loading and HeNe laser. The findings indicate that the combination of these two approaches increased collagen production with marginal biomechanical effects on the repaired tendons.
Reddy et al, in another study,9 exam-ined the effects of HeNe laser on rabbits that had their Achilles tendon tenectomized and repaired in fourteen days. The treatment group had considerably higher collagen content in the tendon than the control group. Collagen extraction from the regenerating tissues yielded significantly higher concentrations of soluble and insoluble salts from the laser group as compared to the control group.
Parizotto and Baranauskas10 performed tendectomies on the Achilles tendons of 32 rats and then repaired them. A laser group was treated with a HeNe laser daily for ten days after the first twenty-four hours. Dosimetry was 0.5, 5, and 50 joules/cm2. Enhanced intra- and intermolecular hydrogen bonding in the collagen molecules were observed in the laser group. The treated tendons were more organized than the control group.
Stupinska11 treated fifty patients suffering from Achilles tendon injuries with a GaAs laser alone or in combination with a HeNe laser. Evaluation of patient responses were based on information gathered from patient examinations and interviews as well as Laitinen Pain Questionnaires. The results proved an analgesic effect.
Demir et al12 performed a study on eighty-four male Swiss albino rats utilizing therapeutic ultrasound, GaAs laser, or both together. There were twenty-eight rats in each of three groups utilizing the left foot as a treatment side and the right foot as a sham or control side. The ultrasound was applied at 0.5 W/cm2 with a frequency of 1MHz continuously for five minutes daily. The laser was 904 nm in wavelength with a 6 mW average power output at 1 joule/cm2 at 16 Hz frequency for one minute. All groups were treated for nine days except for the group that had biochemical testing performed. The latter were treated for four days. Hydroxyproline was measured on the 4th, 10th, and 21st days following initiation of the treatment program. Seven rats were sacrificed in order to obtain biochemical information. Hydroxyproline levels were found to be significantly increased in the treatment groups on the 10th and the 21st days of treatment. The combined ultrasound and laser groups were slightly higher than each one individually. Tendon tensile strength was significantly stronger in both ultrasound and laser groups. Ultrasound and laser therapy were found to be equally effective.12