Detection of Meniscal Changes Prior to Overt Damage Followingacl/mcl Transection in an Ovine Stifle Joint Model of Osteoarthritis
ثبت نشده
چکیده
INTRODUCTION: The anterior cruciat e ligament (ACL) is one of the most frequently injured ligaments in the knee. ACL injury often leads to significant functional impairment in athletes and is associated with induction of degenerative joint disease. ACL injuries are regarded as “the beginning of the end of the knee”. This is because the incidence of meniscal pathology and chondral defects increases in the chronically unstable knee lacking an ACL. However, the mechanism of meniscal pathology after ACL injury is still unclear. The purpose of this study was to determine specifically what effects combined ACL/MCL (medial collateral ligament) transection of the ovine stifle joint had on the remaining intact meniscus, especially from a histological, biochemical and molecular perspective. Understanding the bioprocesses of adaptation on these levels could potentially identify biomolecules which might be delivered therapeutically to encourage or reduce the progression of meniscus deterioration. MATERIALS AND METHODS: Twelve skeletally mature female Suffolk Cross sheep were used in this study which had the approval of our Animal Care Committee. Four animals (eight stifle joints) served as unoperated normal controls while five had a unilateral ACL/MCL transection and three underwent sham operation under general anesthesia. Sheep were walked, incline walked, and trotted on a treadmill daily. At 4-week intervals in vivo kinematic assessments were performed until sacrifice at 20 weeks post surgery [1]. All joints had gross morphological grading [2] followed by harvest of intact menisci. Both medial and lateral menisci were measured and weighed immediately, then dissected into anterior, middle and posterior parts. Each sample was assessed for histological, biochemical and molecular study. Tissues for biochemical analysis were weighed and dried in vacuum to constant weight and then water content calculated. Menisci for histological study were embedded in paraffin, sections cut and stained with Masson’s trichrome and Safranin-O, prior to light microscopic evaluation. The Jackson scales [3] (higher scores indicate worse condition), which is based on cellularity, hyaline cartilage metaplasia, collagen fiber separation, chondrocyte clustering and surface cellularity, was used for histological evaluation. Tissues for RT -PCR were snap frozen in liquid nitrogen and stored at –70 °C until further analysis. RNA was isolated by a method previously described by Reno et al. [4]. Total RNA was quantified fluorometrically using Sybr Green II fluorescent RNA dye. Total RNA from all samples was reversetranscribed using the Qiagen Omniscript RT kit. The PCR was performed using sheep specific primers for type I, II and III collagen, aggrecan, biglycan, decorin, fibromodulin, matrix metalloproteinase-13 (MMP-13), and tissue inhibitor of matrix metalloproteinase-1 (TIMP -1). Statistical analysis consisted of comparing each meniscus from normal, ACL/MCL transected legs, and Sham operated legs using KruskalWallis test and Mann-Whitney’s U test. (p<0.05) RESULTS: At sacrifice, there was no overt meniscal injury from ACL/MCL transected, sham and normal joints, with the exception of one lateral meniscus in a transected joint which had minimal fibrillation in the posterior horn. Despite no gross morphological changes, water content and histological grading changed site specifically. Both the anterior horn and middle part of medial menisci from ACL/MCL transected joints had significantly higher water content. With histological evaluation, there was more cellularity and hyaline cartilage metaplasia in the samples from ACL/MCL transected joints (Fig. 1). In particular, the posterior horn medial menisci had significantly higher grading scores. Analysis of mRNA using RT -PCR demonstrated biglycan mRNA levels were significantly lower in the posterior horn of the medial meniscus from ACL/MCL transected joints. All meniscal samples from transected joints had higher MMP-13 levels (3 fold increase). This expression was prominent in the posterior segment of medial and the anterior segment of lateral menisci, where 10 fold increases in MMP-13 mRNA levels were demonstrated. In contrast to MMP -13 mRNA expression, pronounced changes in TIMP -1 mRNA levels were not evidenced (Fig. 2). A) Normal B) Tx
منابع مشابه
Arthroscopic Findings Following Experimental Cranial Cruciate Ligament Desmotomy in Dog
Objective- Using the arthroscopic surgery technique for experimental transection of cranial cruciateligament and arthroscopic findings of stifle joint following ligament transection .Design- Experimental study.Animals- Five healthy mixed breed dogs. Procedures- Five dogs (mean weight 27±3 kg, mean age 3 years) selected to study the stifle joint changesafter experimental cranial cruciate ligamen...
متن کاملAnalysis of change in gait in the ovine stifle: normal, injured, and anterior cruciate ligament reconstructed
BACKGROUND Many patients who undergo anterior cruciate ligament (ACL) reconstructive surgery develop post-traumatic osteoarthritis (PTOA). ACL reconstructive surgery may not fully restore pre-injury joint biomechanics, thereby resulting in further joint damage and contributing to the development of PTOA. In an ovine model of idealized ACL reconstruction (ACL-R), it has been shown that signs of ...
متن کاملExamination of osteoarthritis and subchondral bone alterations within the stifle joint of an ovariectomised ovine model.
The exact relationship between osteoporosis and osteoarthritis is still a matter for debate for many. The ovariectomised ewe is frequently used as a model for osteoporosis, resulting in significant alterations in bone morphometry and turnover in both trabecular and subchondral bone after 1 year. This study examines whether ovariectomy has any impact on development of osteoarthritis within the o...
متن کاملThe Influence of Oblique Angle Forced Exercise in Surgically Destabilized Stifle Joints Is Synergistic with Bone, but Antagonistic with Cartilage in an Ovine Model of Osteoarthritis
Large animal models of osteoarthritis are a necessary testing ground for FDA approval of human medicine applications. Sheep models have advantages over other available large animals, but development and progression of osteoarthritis in sheep is exceedingly slow, which handicaps progress in development of potential treatments. We combined oblique angle forced exercise to increase stress on the s...
متن کاملEx Vivo Pathomechanics of the Canine Pond-Nuki Model
BACKGROUND Transection of the canine cranial cruciate ligament (CCL) is a well-established osteoarthritis (OA) model. The effect of CCL loss on contact pressure and joint alignment has not been quantified for stifle loading in standing. The purposes of the study were to measure femorotibial contact areas and stresses and joint alignment following transection of the CCL in an ex vivo model. We h...
متن کامل