Effect of adjuvant hyperbaric oxygen on healing of cartilage lesions treated with microfracture: an experimental study in rats

Purpose: The purpose of this experimental study was to investigate the effect of hyperbaric oxygen (HBO2) therapy combined with microfracture technique in the treatment of cartilage lesions.

Methods: Adult Wistar rats (n=44) were divided into six groups. In Groups A, B, C and D, ICRS* (* International Cartilage Repair Society) grade 4 cartilage lesions were made on the femoral sulcus of both knees. Lesions were microfractured on the left knees; the right knees had no further procedure. Groups E and F had no surgery. Groups A, C and E received HBO2 therapy once a day, six days a week postoperatively. Groups B, D and F had no HBO2 therapy. The animals in Groups A, B, E and F were sacrificed after two weeks; Groups C and D were sacrificed after four weeks. Semiquantitative scale - including filling of defect (microfracture hole), reparative tissue thickness, cell morphology and subchondral bone maturation - was used for evaluation. The Mann-Whitney test was used to compare individual and total scores.

Results: Total scores of the two-week group with adjuvant HBO2 therapy were significantly higher (P=0.0007) than the two-week standard treatment group. Except for subchondral bone maturation, individual scores were significantly higher in the two-week group with adjuvant HBO2 therapy. Total scores of the four-week groups were similar. Among individual scores of the four-week groups, filling of the defect (microfracture hole), and subchondral bone maturation were significantly higher (P=0.01, P=0.03) in groups with adjuvant HBO2 therapy.

Conclusions: Adjuvant HBO2 therapy accelerates the healing process of cartilage lesions treated with microfracture in rats.