Histological and magnetic resonance imaging alterations after irradiation of meniscus using Holmium:YAG laser

Low Level Laser Therapy for chronic knee joint pain patients

BACKGROUND AND AIMS

Chronic knee joint pain is one of the most frequent complaints which is seen in the outpatient clinic in our medical institute. In previous studies we have reported the benefits of low level laser therapy (LLLT) for chronic pain in the shoulder joints, elbow, hand, finger and the lower back. The present study is a report on the effects of LLLT for chronic knee joint pain.

MATERIALS AND METHODS

Over the past 5 years, 35 subjects visited the outpatient clinic with complaints of chronic knee joint pain caused by the knee osteoarthritis-induced degenerative meniscal tear. They received low level laser therapy. A 1000 mW semi-conductor laser device was used to deliver 20.1 J/cm(2) per point in continuous wave at 830nm, and four points were irradiated per session (1 treatment) twice a week for 4 weeks.

RESULTS

A visual analogue scale (VAS) was used to determine the effects of LLLT for the chronic pain and after the end of the treatment regimen a significant improvement was observed (p<0.001). After treatment, no significant differences were observed in the knee joint range of motion. Discussions with the patients revealed that it was important for them to learn how to avoid postures that would cause them knee pain in everyday life in order to have continuous benefits from the treatment.

CONCLUSION

The present study demonstrated that 830 nm LLLT was an effective form of treatment for chronic knee pain caused by knee osteoarthritis. Patients were advised to undertake training involving gentle flexion and extension of the knee.

Histological alterations after irradiation of cartilage using Ho:YAG laser

OBJECTIVE

The authors carried out an experimental study to evaluate the histological alterations after irradiation of cartilage using Holmium:YAG (Ho:YAG) laser VersaPulse Select 60 watts and Infra Tome Delivery Systems 30 degrees Handpiece (spot size at fiber tip 0.4 mm; Coherent Medical, Palo Alto, CA).

BACKGROUND DATA

Recently, some authors reported cases with articular cartilage damage following arthroscopic laser surgery in the knee joint for the treatment of articular cartilage or meniscal pathology.

MATERIALS AND METHODS

The cartilage specimens immersed in saline were exposed to Ho:YAG laser irradiation. The laser wavelength was 2.1 microm, and pulse duration was 250 microsec. Power settings were 0.2-1 joules per pulse and 10-15 Hz. Total laser energy used in these procedures was 1.5 K joules. During the procedures, the handpiece was used at an angle of 30 degrees and at a distance of 1 mm.

RESULTS

Electron microscopic evaluation demonstrated that the ultrastructure of the cartilage is preserved in both experiment and control groups.

CONCLUSION

When Ho:YAG laser is used in optimal dosage (optimal joule and Hertz) with optimal technique (keeping the handpiece at an appropriate angle and distance) and avoiding overtreatment, it does not cause cartilage damage.