Effects of a Single Application of Extractum Cepae on the Peritendinous Adhesion: an Experimental Study in Rabbits

Peritendinous adhesion is an important cause of poor functional outcome after flexor tendon repair. The objective of this study was to investigate the effect of a single intraoperative application of extractum cepae, an extract of dietary onion, on the peritendinous adhesion, using a rabbit model of flexor tendon injury. The first, second, and third digits of the right hind paw of 18 rabbits were used for tendon operations. A standard partial division of the synovial sheath and flexor tendon was done at zone II to stimulate the adhesion formation. In the treatment group (n = 9 rabbits, 27 tendons), the flexor tendon sheath was treated with 50 mg/mL of extractum cepae which was applied locally and allowed to infiltrate for 5 minutes, the skin was sutured without suturing the sheath and the tendons. The same operation was done for the control group (n = 9 rabbits, 27 tendons) and 1 mL of normal saline solution was applied locally. Biomechanical and histologic evaluations of the specimens were done after 3 weeks. Tendons from the first toes were used for biomechanical studies. The second and third toe tendons were used for histopathologic evaluation. We have compared the peritendinous adhesions and the ultimate forces in the control and treated tendons. There were no statistically significant differences between the 2 groups with respect to the ultimate loads. Adhesion formation was absent in 1 tendon (5.5%), slight in 8 (44.4%), moderate in 6 (33.3), and severe in 3 tendons (16.7%) in the extractum cepae treated group (n = 18); while in the control group (n = 18), it was absent in 1 tendon (5.5%), slight in 1 tendon (5.5%), moderate in 3 (16.6%), and severe in 13 (72.4%) tendons. There was a significant reduction (P = 0.01) in the peritendinous adhesion in the treated group comparing to the control group. The problem of adhesion formation may be minimized using a single intraoperative application of extractum cepae.