Therapeutic low energy laser improves the mechanical strength of repairing medial collateral ligament

Background and Objectives Low energy laser therapy has been shown to enhance collagen production but its effect on tissue strength is not well reported. We tested the effects of therapeutic laser on the strength of healing medial collateral ligaments (MCLs) in rats. Study Design/Materials and Methods Twenty‐four rats received surgical transection to their right MCL and eight received sham operation. After surgery, 16 received a single dose of gallium aluminum arsenide laser to their transected MCL for 7.5 minutes (n = 8) or 15 minutes (n = 8) and eight served as control with placebo laser, while the sham group didn't receive any treatment. The MCLs were biomechanically tested at either 3 or 6 weeks post‐operation. Results The normalized ultimate tensile strength (UTS) and stiffness of laser and sham groups were larger than control (P