Osteochondral lesion repair of the knee in the rabbit after low-power diode Ga-Al-As laser biostimulation: An experimental study

The purpose of this study was to evaluate whether low-power laser biostimulation of the osteo-chondral lesions of the knee could by itself reduce repair healing time. Surgery was performed on eighteen rabbits; a bilateral osteo-chondral lesion of 2.5 mm in diameter and 2 mm depth was created in the femoral medial condyle with a drill. The left knee of each animal was treated intraoperatively using the diode Ga-Al-As laser (780 nm) with the following parameters: 300 Joules/cm ², 1 Watts, 300 Hertz, 10 minutes; the right knee was left untreated, as control group. The animals were divided into three groups, A, B and C, according to the survival time after surgery, two, six and twelve weeks, respectively. The explants from the femoral condyles, either treated employing laser energy or left untreated, were examined histomorphometrically. Results after laser treatment showed faster healing of the lesion at week 2 (p=0.043) and an overall improvement in cellular morphology (p=0.044), while a more regular aspect of the osteocartilaginous tissue was observed at week 12 (p=0.004). A relationship between laser biostimulation properties and healing of the osteo-chondral defect has been demonstrated.