Biological non-ablative repair of lumbar discs by transforaminal intradiscal laser irradiation: MRI quantitative analysis of the effects-preliminary report.

Degenerative disc disease is a significant reason for low back pain. Low-level laser irradiation (LLLI) of cartilage results in its reshaping and combines with regenerative reaction. A certain pattern of lumbar disc irradiation induces healing reaction and formation of new cartilage. Quantitative MRI analysis of regenerative response of the cartilage is the subject of this investigation. Fifty-one lumbar discs of 28 patients with discogenic low back pain underwent irradiation with 1.56-μm Er fiber laser (1.2 W). Quantitative MRI analysis is performed in STIR regime within 0.93-14.80 months. Signal intensity is estimated from irradiated discs and control measured from adjacent non-irradiated discs and vertebral bones. T2 WI follow-up is performed within a long period (up to 5 years) in selected cases. The mean value of MRI signal intensity from the irradiated discs increased by 14% (p <<< 0.001). The control bone measurement revealed no difference in signal intensity (p = 0.83). The adjacent non-irradiated discs slightly increased their signal (p < 0.05). T2 WI follow-up within 5 years revealed a steady increase of the signal and the irradiated discs healing. LLLI of degenerated intervertebral discs by 1.56-μm Er fiber laser produces increase of MRI disc signal within the first year after treatment that confirms regenerative response of the disc and could lay in the basis of clinical improvement. Further assessment on the effect is mandatory.