LOW-POWER DIODE LASER STIMULATION OF SURGICAL OSTEOCHONDRAL DEFECTS: RESULTS AFTER 24 WEEKS

Figures & data

Table I. Scoring System for Histologic and Morphometric Results (Maximum = 12 Points). Samples (n.6 per Group) Were Prepared 24 Weeks After Surgery

Grading Scale		Lased 24 Weeks n. 6 Samples	Not Lased 24 Weeks n. 6 Samples
Cell morphology	Score
Normal	4	—	—
Mostly hyaline cartilage	3	3	—
Mixed hyaline and fibrocartilage	2	2	—
Mostly fibrocartilage	1	1	—
Mostly nonchondrocytic cells	0	—	6
Mean cell morphology		2.31§	0
Matrix staining
Normal	4	—	—
Slightly reduced	3	2	—
Reduced	2	2	—
Significantly reduced	1	1	—
No staining	0	1	6
Mean matrix straining		1.8^*	0
Filling of defect
100%	2	4	1
Overfill	1	2	3
−100%	0	—	2
Mean filling of defect		1.73#	0.8
Surface regularity
Regular, smooth	2	3
Slightly irregular	1	3	1
Irregular	0	—	5
Mean surface regularity		1.5	0.2
Mean for each group		7.34‡	1

Legend:

§ laser vs not lased p = <0.001;

^*laser vs not lased p = 0.012;

# laser vs not lased p = 0.05; laser vs not lased p = <0.001;

‡ laser vs not lased p = <0.001.

Figure 1. Osteochondral defect at 24 weeks after laser treatment (toluidine blue). Magnification: ×10. Complete healing of the osteochondral defect surgically created; the arrow shows the border between repaired tissue (right) and adjacent tissue (left). The repaired tissue has an overall good structural integrity with a smooth and regular articular surface.

Table II. Mean Cell Density ± SD of the Lased Specimens. Each Sample Is the Result of the Comparison Between the Cartilage Repaired Using the Laser and the Cartilage Adjacent to the Lesion

Figure 2. Osteochondral defect at 24 weeks after laser treatment (safranin-0 and picrosirius red). Magnification: ×20. Cartilaginous cells appear arranged in a palisade structure; matrix staining of the reconstituted cartilage is more intense for both proteoglycans and collagen in the deepest layers.

Figure 3. Osteochondral defect at 24 weeks without laser treatment (toluidine blue). Magnification: ×2.5. The repaired tissue appears disorganized and reveals an irregular growth of the reconstituted bony tissue, a thin layer of fibrous tissue on the articular surface and the absence of chondrocytes.