title: The effect of nonablative laser energy on joint capsular properties. An in vitro histologic and biochemical study using a rabbit model.
abstract: The purpose of this study was to evaluate the effect of laser energy at nonablative levels on joint capsular histologic and biochemical properties in an in vitro rabbit model. The medial and lateral portions of the femoropatellar joint capsule from both stifles of 12 mature New Zealand White rabbits were used. Specimens were divided into three treatment groups (5 watts, 10 watts, and 15 watt) and one control group using a randomized block design. Specimens were placed in a 37 degrees bath of lactated Ringer's solution and laser energy was applied using a holmium:yttrium-aluminum-garnet laser in four transverse passes across the tissue at a velocity of 2 mm/sec with the handpiece set 1.5 mm from the synovial surface. Histologic analysis revealed thermal alteration of collagen (fusion) and fibroblasts (pyknosis) at all energy densities, with higher laser energy causing significantly greater morphologic changes over a larger area (P < 0.05). Application of laser energy did not significantly alter the biochemical parameters evaluated, including type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I Collagen content and nonreducible corsslinks were not significantly altered.
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison 53706, USA.
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.forename: G
authors.initials: G
authors.lastname: Thabit
authors.forename: A C
authors.initials: AC
authors.lastname: Vailas
authors.forename: J J
authors.initials: JJ
authors.lastname: Bogdanske
authors.forename: A J
authors.initials: AJ
authors.lastname: Cooley
authors.forename: M D
authors.initials: MD
authors.lastname: Markel
mesh_terms: D000538:Aluminum Silicates; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001669:Biochemical Phenomena; D001671:Biochemistry; D003094:Collagen / Q000032:analysis; D004195:Disease Models, Animal; D005269:Femur / Q000737:chemistry / Q000473:pathology*; D005347:Fibroblasts / Q000473:pathology; D006695:Holmium; D006358:Hot Temperature / Q000009:adverse effects; D006909:Hydroxyproline / Q000032:analysis; D017746:Joint Capsule / Q000737:chemistry / Q000473:pathology*; D007834:Lasers; D010329:Patella / Q000737:chemistry / Q000473:pathology*; D011817:Rabbits; D011897:Random Allocation; D013583:Synovial Membrane / Q000033:anatomy & histology; D015019:Yttrium
chemical_list: D000538:Aluminum Silicates; D000596:Amino Acids; D015019:Yttrium; C015484:pyridinoline; D003094:Collagen; D006909:Hydroxyproline; D006695:Holmium