Suture Plication, Thermal Shrinkage, and Sclerosing Agents

Abstract

Background Shortening or tightening of dense, collagenous tissues is often desirable in the treatment of laxity. Purpose To compare the effect of stress-protection suture, radiofrequency thermal shrinkage combined with stress-protection suture, and a 5% sodium morrhuate sclerosing injection on the length and biomechanical strength of the rat patellar tendon. Hypothesis Sclerosing agents will increase tendon mechanical strength. Thermal shrinkage combined with stress-protection suture and stress-protection suture only will cause a short-term decrease in tendon strength. All 3 methods will produce equivalent shortening of the tendon. Study Design Controlled laboratory study. Methods Forty-six female retired breeder rats were split into 4 groups, each receiving 1 of the 3 aforementioned treatments plus a control group that received a saline injection. After 4 weeks’ survival, the length and biomechanical properties of the patellar tendons were measured and compared to the contralateral untreated tendon. Results Rats treated with stress-protection suture had shorter tendons. Radiofrequency thermal shrinkage combined with stress-protection suture yielded tendons that were both shorter and stronger than were the untreated contralateral tendons. The sodium morrhuate-injected tendons were stronger whereas the saline-treated tendons were weaker than were their respective untreated contralateral tendons. Conclusion Surgical stress-protection suture without radiofrequency shrinkage is most effective at shortening the length of the rat patellar tendon, whereas radiofrequency thermal shrinkage combined with stress-protection suture as well as sodium morrhuate are effective at increasing the strength of rat patellar tendons. Clinical Relevance Judicious use of thermal shrinkage in combination with stress protection may improve ligament strength and decrease laxity.