Reactions of meniscal tissue after arthroscopic laser application: an in vivo study using five different laser systems

Laser photobiomodulation for cartilage defect in animal models of knee osteoarthritis: a systematic review and meta-analysis

To review and assess the efficacy of laser photobiomodulation for cartilage defect in animal models of knee osteoarthritis (KOA). Medline, Web of Science, and EMBASE were searched. Studies were considered if the global quality score of cartilage were parallelly reported between laser and untreated control groups. The methodological quality of each study was assessed using a modified 10-item checklist. The effect size was estimated by standardized mean difference (SMD) and pooled based on the random-effects model. Stratified analysis and regression analysis were conducted to partition potential heterogeneity. An adjusted significant level of 0.01 was acceptable. Five hundred eight initial search recordings were identified, of which 14 studies (including 274 animals) were included for quantitative analysis. The global quality scores mostly weighted by the structural integrity and chondrocyte distribution were measured by different four scales including Histologic Histochemical Grading System (HHGS), Osteoarthritis Research Society International (OARSI), Pineda, and Huang. There were considerable variances on laser parameters and irradiation time among those included studies. Overall, a moderate level of methodological qualities was determined. The synthesis results indicated that the SMD effect size was significantly larger in HHGS (z = 2.61, P = 0.01) and Huang (z = 4.90, P < 0.01) groups. Stratified by irradiance, SMD of low (< 1 W/cm²) but not high (≥ 1 W/cm²) level estimated significant difference (z = 5.62, P < 0.01). Meta-regression identified a significant association for SMDs and irradiation time (P < 0.01). Yet, Egger's test detected small study effect (P < 0.01). No individual study with significant variance was found in homogeneity tests. The results demonstrated the positive effect of laser photobiomodulation for cartilage defect in animal models of KOA under proper irradiance and adequate irradiation time.

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.

Osteonecrosis of the knee after laser or radiofrequency-assisted arthroscopy: treatment with minimally invasive knee arthroplasty

BACKGROUND

Osteonecrosis of the knee after various arthroscopic procedures associated with the use of laser or radiofrequency devices has been described in a few case reports. The purpose of this study was to report on a series of nineteen patients with osteonecrosis of the knee after arthroscopic procedures. A literature search was done to compare this series of patients to previously reported cases. In addition, we analyzed the outcome after treatment with minimally invasive knee arthroplasty.

METHODS

We studied patients who had development of osteonecrosis of the knee after a routine arthroscopic procedure. Preoperative and postoperative clinical notes, radiographs, and magnetic resonance images of patients were analyzed. Only those patients with no evidence of osteonecrosis on preoperative magnetic resonance imaging who later had development of osteonecrosis and subsequently required a knee arthroplasty were included. We conducted a search of the current literature to compare the results seen in our patient population with those seen in other patients with this entity. Patients were followed both clinically and radiographically for a mean of sixty-two months.

RESULTS

A total of nineteen patients met the inclusion criteria. There were fourteen women and five men with a mean age of sixty-nine years. Six patients underwent an arthroscopy with associated holmium or yttrium-aluminum-garnet laser treatment, ten patients had associated radiofrequency treatment, and three patients had microfracture surgery. Subsequent arthroplasty procedures included four unicompartmental knee arthroplasties and fifteen tricompartmental knee arthroplasties. At the time of final follow-up, the mean Knee Society objective score was 95 points.

CONCLUSIONS

Arthroscopic procedures may play a role in the development of osteonecrosis of the knee. To our knowledge, this is the largest series of patients to have development of this condition after arthroscopy with associated laser, radiofrequency, or microfracture surgery. The midterm results of knee arthroplasty in this unique patient population are comparable with those of patients undergoing knee arthroplasty for osteoarthritis of the knee.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Mid-IR laser ablation of articular and fibro-cartilage: a wavelength dependence study of thermal injury and crater morphology

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate areas of collateral thermal injury and crater morphology for evidence of wavelength-dependent effects on the ablation of articular cartilage and fibro-cartilage (meniscus) using selected mid-IR wavelengths produced by a free electron laser.

STUDY DESIGN/MATERIALS AND METHODS

Two types of cartilage, articular cartilage and fibro-cartilage were used in the study. The wavelengths (lambda) evaluated were 2.79, 2.9, 6.1, and 6.45 microm generated by a free electron laser (FEL) using a 4 microseconds macropulse configuration. The zone of thermal injury and crater morphology produced by laser ablation were examined by light microscopy following standard histologic processing.

RESULTS

The zone of thermal injury and crater morphology created in cartilage by the FEL at selected mid-IR wavelengths were examined as a function of incident radiant exposure. Ablation using lambda = 6.1 microm provided the largest crater size for both articular and fibro-cartilage at all radiant exposures. For the zones of collateral thermal injury in articular cartilage, lambda = 6.1 microm produced the least thermal injury at the radiant exposure of 7.6 J/cm2. When the radiant exposure is increased to 20.4 J/cm2, both lambda = 6.1 and 6.45 microm produced less thermal injury than the ablation using lambda = 2.79 and 2.9 microm. The greatest amount of collateral thermal injury was produced by lambda = 2.79 microm for both tissue types.

CONCLUSIONS

The results demonstrate that crater depth and collateral thermal injury produced in articular cartilage and fibro-cartilage are wavelength-dependent with 6.1 microm providing the largest craters at all radiant exposures. The least amount of thermal injury was created in articular cartilage using lambda = 6.1 microm at the radiant exposure of 7.6 J/cm2. Both 6.1 and 6.45 microm wavelengths demonstrated similar amount of thermal injury at 20 J/cm2 that was less than lambda = 2.79 and 2.9 microm at similar fluences. These observations are explained based on the absorption by water and protein in the tissue types studied. It is further observed that the use of crater dimensions may not provide a reliable estimate for the amount of tissue removal provided by an ablation procedure.

Free electron laser ablation of articular and fibro-cartilage at 2.79, 2.9, 6.1, and 6.45 ?m: Mass removal studies

BACKGROUND AND OBJECTIVE

The wavelength and tissue-composition dependence of cartilage ablation was examined using selected mid-infrared laser wavelengths.

STUDY DESIGN/MATERIALS AND METHODS

The mass removal produced by pulsed laser ablation of articular and fibro-cartilage (meniscus) were measured. The wavelengths examined were 2.79, 2.9, 6.1, and 6.45 microm and provided by a free electron laser (FEL) emitting 4 microsecond macropulses consisting of 1-2 picoseconds duration micropulses delivered at 350 picosecond intervals. The measurement of tissue mass removal was conducted using a microbalance during laser ablation.

RESULTS

These studies demonstrated that for articular cartilage the highest mass removal was achieved at lambda = 6.1 microm followed by, in order, lambda = 2.79, 2.9, and 6.45 microm. In comparison, the maximum mass removal for fibro-cartilage was achieved using lambda = 6.1 microm radiation with no statistically significant differences in mass removal provided by the other wavelengths. In evaluation of the comparative influence of each wavelength on tissue type, there was no difference in ablation efficiency between articular and fibro-cartilage at lambda = 6.1 microm. However, the ablation efficiency of articular cartilage was higher than that of fibro-cartilage at both lambda = 2.79 and 2.9 microm. By contrast, lambda = 6.45 microm radiation ablated fibro-cartilage more efficiently than articular cartilage at radiant exposures greater than 12 J/cm2.

CONCLUSIONS

The mass removal of articular and fibro-cartilage produced by FEL ablation at selected mid-IR wavelengths was measured as a function of incident radiant exposure. The ablation efficiency was found to depend on both wavelength and tissue type. The 6.1 microm wavelength was found to provide the highest ablation efficiency for both articular and fibro-cartilage.