TENDON REPAIR BY LASER-WELDING - A HISTOLOGIC AND BIOMECHANICAL COMPARISON AND SUTURE REPAIR WITH CO2 AND ARGON-LASERS

Background and Objective: The purpose of this study was to determine w hether welding of tendinous tissue is possible with the application of thermal lasers,Study Design Materials and Methods: After sharp transe ction of a unilateral achilles tendon, 40 male outbred Spraque Dawley rats were divided equally between four treatment groups, Ten animals u nderwent repair using the modified Kessler suture technique, The remai ning animals underwent application of laser after the tendon edges wer e reapproximated and held in place with a vascular clamp, CO2 and Nd:Y AG lasers were applied using 25% human albumin as a solder, Fluorescei n dye was added to albumin and used as solder for the Argon laser, Bio mechanical and histologic testing were performed immediately and 14 da ys postoperatively. Results: Argon and CO2 lasers successfully fused t he tendon ends together. However, immediately postoperative, the resul tant tissue weld was tenuous and conventional tensile strength testing was not possible. At 14 days postoperatively, all modes of tendon rep air resulted in tensile failure at consistently lower levels of tensio n than those required for the normal uninjured tendons. The ultimate t ensile strength for the suture-repaired, CO2 laser welded, and Argon l aser welded tendons were 74%, 59%, and 64% of the strength of the cont rol tendons respectively, No statistically significant difference was found in the tensile strength among the three repair groups. Histologi c evaluation at 14 days revealed the greatest degree of inflammatory r esponse in those tendons repaired with the Argon laser, Those tendons repaired with suture demonstrated the least amount of inflammatory cha nge. Conclusion: Our study demonstrates that welding of a tendon is po ssible with the application of laser energy. However, we were unable t o produce a weld sufficient to withstand significant tensile loads in the immediate postoperative period. (C) 1996 Wiley-Liss, Inc.