Partial Cruciate Ligament Rupture Research Articles

Proinflammatory polarization of stifle synovial macrophages in dogs with cruciate ligament rupture.

To determine polarization of synovial macrophages during development of cruciate ligament rupture (CR) and determine whether differences in synovial macrophage polarization in CR, osteoarthritis (OA), and healthy joints exist. Prospective case-controlled study. Client-owned dogs with unstable stifles with CR (n = 22), paired stable contralateral stifles with partial CR (pCR; n = 7), joints with OA not related to CR (n = 6), and clinically normal (Normal; n = 7) joints. Synovial fluid samples were collected. Smears were made for differential cytology counts and estimated total nucleated cell counts. Cytospin preparations were made, and immunocytochemical staining was performed with the pan-macrophage marker CD68, M1 macrophage markers inducible nitric oxide synthase (iNOS) and chemokine (C-C motif) receptor 7 (CCR7), and M2 macrophage markers arginase 1 and CD163. Positively stained cells were counted. Numbers of lymphocytes were increased in the CR group compared with the OA and Normal groups (P < .05). Numbers of CD68+ , CCR7+ , and iNOS+ cells in the CR and OA groups were increased compared with the Normal group (P < .05). Globally, the ratio of positively stained M1 polarized CD68+ cells to M2 polarized CD68+ cells was highest for the OA group (2.49), followed by the pCR (2.1), CR (1.63), and Normal (0.7) groups. Polarization of synovial macrophages toward an M1 proinflammatory phenotype is an early event in the development of canine CR. M1 polarization in pCR stifles provides evidence of a possible role for macrophages in progressive development of cruciate ligament fiber damage. Lymphocytes may play a role in the synovitis found in CR joints. Our findings provide evidence that these cells are therapeutic targets.

Use of a platelet-rich plasma-collagen scaffold as a bioenhanced repair treatment for management of partial cruciate ligament rupture in dogs.

Dogs are commonly affected with cruciate ligament rupture (CR) and associated osteoarthritis (OA), and frequently develop a second contralateral CR. Platelet rich plasma (PRP) is a component of whole blood that contains numerous growth factors, which in combination with a collagen scaffold may act to promote bioenhanced primary repair of ligament. This study tested the hypothesis that treatment of partial stable CR stifles with an intra-articular collagen scaffold and PRP would decrease the disease progression, synovitis and risk of complete CR over a 12-month study period. We conducted a prospective cohort study of 29 client-owned dogs with an unstable stifle due to complete CR and stable contralateral stifle with partial CR. All dogs were treated with tibial plateau leveling osteotomy (TPLO) on the unstable stifle and a single intra-articular application of PRP-collagen in the stable partial CR stifle. Dogs were evaluated at the time of diagnosis, and at 10-weeks and 12-months after treatment. We evaluated correlation between both development of complete CR and time to complete CR with diagnostic tests including bilateral stifle radiographs, 3.0 Tesla magnetic resonance (MR) imaging, and bilateral stifle arthroscopy. Additionally, histologic evaluation of synovial biopsies, C-reactive protein (CRP) concentrations in serum and synovial fluid, and synovial total nucleated cell count, were determined. Results indicated that a single application of PRP-collagen in partial CR stifles of client owned dogs is not an effective disease-modifying therapy for the prevention of progression to complete CR. Radiographic effusion, arthroscopic evaluation of cranial cruciate ligament (CrCL) damage, and MR assessment of ligament fiber tearing in partial CR stifles correlated with progression to complete CR over the 12-month follow-up period. We determined that the best predictive model for development of complete CR in PRP-collagen treated partial CR stifles included variables from multiple diagnostic modalities.

Radiographic and magnetic resonance imaging predicts severity of cruciate ligament fiber damage and synovitis in dogs with cranial cruciate ligament rupture.

Cruciate ligament rupture (CR) and associated osteoarthritis (OA) is a common condition in dogs. Dogs frequently develop a second contralateral CR. This study tested the hypothesis that the degree of stifle synovitis and cranial cruciate ligament (CrCL) matrix damage in dogs with CR is correlated with non-invasive diagnostic tests, including magnetic resonance (MR) imaging. We conducted a prospective cohort study of 29 client-owned dogs with an unstable stifle due to complete CR and stable contralateral stifle with partial CR. We evaluated correlation of stifle synovitis and CrCL fiber damage with diagnostic tests including bilateral stifle radiographs, 3.0 Tesla MR imaging, and bilateral stifle arthroscopy. Histologic grading and immunohistochemical staining for CD3+ T lymphocytes, TRAP+ activated macrophages and Factor VIII+ blood vessels in bilateral stifle synovial biopsies were also performed. Serum and synovial fluid concentrations of C-reactive protein (CRP) and carboxy-terminal telopeptide of type I collagen (ICTP), and synovial total nucleated cell count were determined. Synovitis was increased in complete CR stifles relative to partial CR stifles (P<0.0001), although total nucleated cell count in synovial fluid was increased in partial CR stifles (P<0.01). In partial CR stifles, we found that 3D Fast Spin Echo Cube CrCL signal intensity was correlated with histologic synovitis (SR = 0.50, P<0.01) and that radiographic OA was correlated with CrCL fiber damage assessed arthroscopically (SR = 0.61, P<0.001). Taken together, results of this study show that clinical diagnostic tests predict severity of stifle synovitis and cruciate ligament matrix damage in stable partial CR stifles. These data support use of client-owned dogs with unilateral complete CR and contralateral partial CR as a clinical trial model for investigation of disease-modifying therapy for partial CR.

Treatment of stable partial cruciate rupture (Grade 1 sprain) in five dogs with tibial plateau levelling osteotomy

Tibial plateau levelling osteotomy (TPLO) is increasingly being used for treatment of stable partial cruciate ligament rupture (CR) in dogs. Medical records for TPLO‐treated dogs from 2003 to 2014 were reviewed and five cases were identified. Data retrieved included physical examination, diagnostic imaging and treatment. At long‐term follow‐up, the outcome was evaluated by clinical examination, stifle radiographs and force platform gait analysis. The time to follow‐up examination was 892±673 days for six stable stifle TPLO treatments in five dogs. Stifles with partial CR remained cranial drawer and cranial tibial thrust negative at follow‐up, with little progression of stifle osteoarthritis (OA). These observations suggest that TPLO is an effective clinical treatment for dogs with lameness because of partial CR. TPLO treatment reduces cranial cruciate ligament (CrCL) strain, based on ex vivo model studies. Clinically, TPLO may act to block fibre tearing in the CrCL and associated progression of stifle OA in dogs with partial CR.