Related Experiment Video
Updated: Aug 16, 2026
Evaluation of Stem Cell Therapies in a Bilateral Patellar Tendon Injury Model in Rats
Published on: March 30, 2018
Suture plication, thermal shrinkage, and sclerosing agents: effects on rat patellar tendon length and biomechanical
Arun Aneja1, Spero G Karas, Paul S Weinhold
1Department of Orthopaedics, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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.
