Journal Article Review September 2019

The effect of polarized light for prevention and treatment of CRPS following distal radius fracture

Zlatkovic-Svenda MI et al: Complex Regional Pain Syndrome (Sudeck Atrophy) Prevention Possibility and Accelerated Recovery in Patients with Distal Radius at the Typical Site Fracture Using Polarized, Polychromatic Light Therapy. Photobiomodul Photomed Laser Surg. 2019 Apr;37(4):233-239

Investigators from Serbia and Bosnia and Herzegovina recently reported on the effects of polychromatic (i.e., not laser, which is monochromatic) polarized light used during the rehabilitation after distal radius fractures (DRF) in a prospective study of older women, average age 63.

Fifty-two patients were enrolled in the study and were randomly divided into two equal and age matched groups. Upon cast removal, both groups received daily treatment at home for 15 days that included non-steroidal anti-inflammatory drugs, exercises, and cryotherapy (ice) applied to the dorsum of the hand and wrist. One group also received polarized, polychromatic low-energy light radiation. All patients were evaluated at days 0, 7, and 15 with a pain visual analog scale (VAS) score, and measurements of forearm pronation and supination. Also measured were fist-forming capacity at 15 days and the presence or absence of CRPS-induced complications that occurred within the first 6 months.

Results

The VAS scores were not significantly different at days 0 and 7 and were marginally, yet statistically significantly, different at day 15, p = .046. Supination was significantly different at both days 7 and 15 in favor of the light-treated group, with an improvement of 9 degrees over the control group at 15 days. Pronation was not significantly different at either 7 or 15 days. Fist-forming capability was not statistically different between the groups. At 6-month follow-up, 15% of the control group had manifested signs of CRPS whereas none of the light-treated group had been so affected. This difference was statistically significant.

Discussion

The light source is a proprietary device, Bioptron (Wollerau, Switzerland); and polarized, polychromatic light requires no special training or protection as does low-level laser therapy. Polarized, polychromatic light is said to penetrate to different levels through the skin and change cell membrane permeability, stimulate mitochondria to increase availability of ATP, stimulate microcirculation through the production of nitric oxide, stimulate immune parameters, increase fibroblastic collagen production, and alter pain perception. The authors provide references to previous studies that support these claims. They also offer references to studies that report the successful use of polarized, polychromatic light in sports medicine, kidney failure, and for treatment of CRPS.

The authors conclude:  “…low-energy, polarized, and polychromatic light therapy combined with conventional therapy … in patients with DRF appears a better choice and treatment option for pain control improvement and a range of motion achievement; it also significantly reduces CRPS occurrence after DRF in gerontology.”

Comment

Where to start? In a table, the authors enumerate the parameters of the light therapy device. It has wavelengths from 480 nanometers (blue) to 3400 nm (infrared), yet at least 95% polarization is only from 590 (orange) to 1550 nm (low infrared). So a broad spectrum of the emitted light is not polarized. They also list the power density, light intensity, and light energy per minute, but I have no frame of reference for comparison of any of these parameters. I would like to know how this device’s parameters compare to an LED flashlight.

Although age-matched, the authors did not classify the fractures by pattern (intra-articular vs extra-articular) or degree of displacement. In other words, the groups may have been quite different without the investigators’ knowledge.

The study was not blinded, and the treating therapist collected the measurements, both which introduce the possibility of bias. For unexplained reasons, the investigators did not measure wrist flexion and extension, only fist formation and forearm rotation.

Nor did they report forearm motion beyond the 15 days of therapy. It is unclear whether the 6-month follow-up seeking evidence of CRPS was by direct examination or by questionnaire or phone evaluation. In either case, the diagnosis of CRPS is arbitrary and likely differs from observer to observer.

As hard as it is for me to comprehend, light may have salutary tissue effects, it certainly does on melanin and vitamin D production in the skin. The farther beneath the skin the claims go, the more skeptical I become. This paper did nothing to reduce my skepticism.