Effect of nonablative laser energy on the joint capsule: An in vivo rabbit study using a holmium: YAG laser

Abstract

Background and Objective The nonablative application of holmium:yttrium‐aluminum‐garnet (Ho:YAG) laser energy to the joint capsule of patients with glenohumeral instability has been found to shrink capsular tissue and to help stabilize the joint. The purpose of this study was to evaluate the effect of nonablative laser energy on the short‐term histological properties of joint capsular tissue in an in vivo rabbit model. Study Design/Materials and Methods Eighteen mature New Zealand white rabbits were used in this study. One randomly selected stifle was treated with laser energy, and the contralateral stifle was sham‐operated. Animals were euthanized immediately after surgery (day 0), at 7 days postsurgery and 30 days postsurgery. Specimens were processed for histology and transmission electron microscopy. Results Laser‐treated samples at day 0 showed diffuse hyalinization of collagen with nuclear karyorrhexis of fibroblasts. Laser‐treated tissue at 7 days postsurgery revealed fibroblast proliferation around and into acellular hyalinized regions of collagen. At 30 days postlaser treatment, areas of fused collagen were greatly reduced as large reactive fibroblasts migrated and secreted matrix. Conclusion This study illustrates the short‐term in vivo tissue response to nonablative laser treatment, where acellular hyalinized regions of collagen are infiltrated by fibroblasts that have used the treated collagen as the framework for migration and secretion of new collagen matrix in order for tissue repair to proceed. Lasers Surg. Med. 20:164–171, 1997. © 1997 Wiley‐Liss, Inc.

Thermal-Assisted Capsular Shrinkage of the Glenohumeral Joint in Overhead Athletes: A 15- to 47-Month Follow-up

“…Recently the application of thermal energy as a means to selectively shrink the glenohumeral capsule using an arthroscopic procedure has been advocated. 4,[7][8][9]18 In our current study, we examined the functional outcomes of 130 overhead athletes undergoing TACS at a mean follow-up of 29 months (range, 15-47 months). The results of our study indicate superior outcomes to those which reported using open and arthroscopic stabilization procedures without TACS, 3,12,15,17,20,[22][23][24]29 and similar to those of Savoie and Field, 25 Lyons et al, 16 and Levitz et al, 14 which used TACS.…”

“…The rehabilitation program utilized in this study is based on the authors' clinical experience of over 700 patients treated with TACS between 1997 and 2003, the effects of mobilization on collagen tissue healing, 1,6,34,36 and the basic science of collagen tissue healing following thermal modification. [7][8][9]18,19,[27][28]34 The rehabilitation program follows a gradual progression of applied loads on the collagen tissue to restore range of motion as the strength and tensile properties of the collagen tissue gradually returns to the preoperative state. The use of immediate motion is based on the theory that gentle passive motion is beneficial to the restoration of the organization, alignment, and strength of collagen tissue.…”

“…Range of motion was progressed cautiously during the first 6 to 8 weeks secondary to the reduced tensile properties of the collagen tissue. [7][8][9]19 Our goal was to have 75°of ER at 90°of shoulder abduction at week 6, and 90°by week 8. Shoulder flexion should be to 180°by week 8.…”

“…4,[7][8][9]18 Thermal energy, in the form of heat, has been used in medicine dating back to Hippocrates. The authors of the current study 34 have previously discussed the basic science and clinical application of thermal-assisted capsular shrinkage (TACS) of the glenohumeral joint capsule.…”

“…The authors of the current study 34 have previously discussed the basic science and clinical application of thermal-assisted capsular shrinkage (TACS) of the glenohumeral joint capsule. Since the 1990s, thermal energy has been used to modify capsular tissue in orthopedics 4,[7][8][9]18 and may be applied using 2 types of probes: the Holium:YAG laser and the radiofrequency heat probe. Both methods of thermal delivery have been shown to achieve similar and predictable amounts of capsular shrinkage in the cadaveric and ovine model, depending on the temperature settings.…”