Degree Of Articular Cartilage Degeneration Research Articles

Total meniscus replacement with a 3D printing of network hydrogel composite scaffold in a rabbit model.

The aim of this study was to evaluate the role of a novel total meniscal implant in promoting meniscal regeneration and protecting articular cartilage in a rabbit model for 3 and 6 months. Thirty-six New Zealand rabbits were selected and divided into poly(ɛ-caprolactone) (PG-Pg) scaffold group, meniscectomy group and sham group. In this study, it was investigated whether PG-Pg scaffold can prevent articular cartilage degeneration and promote tissue degeneration, and its mechanical properties at 3 and 6 months after surgery were also explored. The degree of articular cartilage degeneration was significantly lower in the PG-Pg scaffold group than in the meniscectomy group. The number of chondrocytes increased in the PG-Pg scaffold at 3 and 6 months, while a gradual increase in the mechanical properties of the PG-Pg stent was observed from 6 months. The PG-Pg scaffold slows down the degeneration of articular cartilage, promotes tissue regeneration and improves biomechanical properties after meniscectomy. This novel meniscus scaffold holds promise for enhancing surgical strategies and delivering superior long-term results for individuals with severe meniscus tears. NA.

Inhibition of fibrotic changes in infrapatellar fat pad alleviates persistent pain and articular cartilage degeneration in monoiodoacetic acid-induced rat arthritis model

We have reported that fibrotic changes in infrapatellar fat pad (IFP) after acute joint inflammation are closely associated with persistent pain in rats. In this study, to examine the effects of anti-fibrotic treatment on persistent pain, we used C-type natriuretic peptides (CNP) at the recovery phase after acute joint inflammation. Thirty-two male Wistar rats were used in this study. Monoiodoacetic acid (MIA) was injected intra-articularly to induce IFP fibrosis and persistent pain. CNP was injected after acute inflammatory phase in the same knee joint. Time-course pain-avoidance behavior tests and histological analyses were performed to examine the effects of CNP. Histological evaluations indicated that intra-articular injection of CNP inhibited fibrotic changes in IFP after acute inflammation. Incapacitance tests indicated that MIA injection into rat knee joint quickly decreased the percent weight on ipsilateral limb. In the vehicle group, the decrease was maintained up to day 28, suggesting that pain persistence occurred after acute inflammation (Day 0/Day 28, Est Dif-8.15, CI -10.78∼-5.53, Linear mixed-effect model). In contrast, the pain was alleviated in the CNP group after day 14 (Day0/Day 14, -0.51,-2.62-1.59). In addition, we observed significant improvement in the degree of articular cartilage degeneration at day 14 in the CNP group (OARSI score: vehicle 16.14±4.37 vs CNP 6.87±3.44, P<0.01; Wilcoxon rank sum test). Fibrotic changes in IFP may play important roles in both persistent pain and articular cartilage degeneration.

Effect of Lubricin Mimetics on the Inhibition of Osteoarthritis in a Rat Anterior Cruciate Ligament Transection Model

Background: Lubricin, a mucinous glycoprotein, plays a chondroprotective role as a constituent of synovial fluid. Structural analogs have been synthesized to mimic the structure and function of native lubricin in an effort to recapitulate this effect with the goal of delaying progression of osteoarthritis (OA). Purpose: To investigate the efficacy of intra-articular injections of lubricin mimetics in slowing or preventing the progression of posttraumatic OA by using a rat anterior cruciate ligament transection model. Study Design: Controlled laboratory design. Methods: Four lubricin mimetics were investigated, differing from one another in their binding orientations and steric interactions. Eighty skeletally mature Sprague-Dawley rats underwent bilateral anterior cruciate ligament transections and were randomly allocated to receive intra-articular injections (50 µL/injection) of 1 of the 4 mimetics in the right knee and equal volumes of saline injection in the contralateral knee (control). All rats were euthanized 8 weeks postoperatively and assessed via biomechanical analysis, which evaluated comparative friction coefficients across the 4 groups, and histological evaluation of articular cartilage, osteophytes, and synovitis. The Osteoarthritis Research Society International (OARSI) histopathological assessment system was used to evaluate the degree of articular cartilage degeneration and osteophytes, while synovitis was assessed through a semiquantitative scoring system. Binding efficacy of the 4 mimetics was assessed in vitro and in vivo through the immunohistochemical localization of polyethylene glycol. Articular cartilage degeneration and synovitis scoring data analyses were performed with generalized estimating equation modeling. Results: Injection of the group 3 mimetic (random 24 + 400 + 30) directly correlated with improved OARSI scores for femoral articular cartilage degeneration when compared with saline-injected contralateral control knees (P = .0410). No lubricin mimetic group demonstrated statistically significant differences in OARSI scores for tibial articular cartilage degeneration. Injection of the group 4 mimetic (AB 24 + 400 + 30) led to a statistically significant difference in osteophyte OARSI score (P = .0019). None of the 4 lubricin mimetics injections incited an additive synovial inflammatory response. Immunohistochemical staining substantiated the binding capacity of all 4 mimetics, while in vivo experimentation revealed that the group 1 and 3 mimetics were still retained within the joint 4 weeks after injection. There were no differences in friction coefficients between any pair of groups and no significant trends based on lubricin mimetic structure. Conclusion: We demonstrated that the tribosupplementation of a traumatically injured knee with a specific lubricin structural analog may attenuate the natural progression of OA. Clinical Relevance: The current lack of efficacious clinical options to counter the onset and subsequent development of OA suggests that further investigation into the synthesis and behavior of lubricin analogs could yield novel translational applications.

Leg pain behavior correlates fibrosis and angiogenesis of the infrapatellar fat pad induced by monoiodoacetic acid

Purpose: Chronic knee pain is the major complaint of patients suffering from knee osteoarthritis (OA). Although, conservative therapy is usually applied in such cases, clinical outcomes are not always satisfactory to all the patients. One reason for that may be due to the complexity of pain etiology, which may differ from each patient. Severity of chronic knee pain usually associates with the degree of articular cartilage degeneration, however, non-negligible numbers of patients with relatively normal articular cartilage also have severe pain in clinical settings. Infrapatellar fat pad (IFP) is a cylindrical piece of fat situated behind the patella tendon. It is considered that the IFP plays significant roles in knee pain since it contains blood vessels and sensory nerves besides joint inflammation. In addition, we often observe inflammatory response within this tissue after joint injury or OA. To understand the IFP-related knee pain, we established a chemical induced IFP inflammation model in rats and examined the relation between the pain behavior and histological observations of IFP in this study. Methods: Male Wistar rats received injection of MIA (monoiodoacetic acid, 0.2 mg or 1.0 mg/10 μl) in the left IFP, and PBS (10 μl) in the right IFP. To prevent leakage of the solution into the knee joint as well as to avoid influence of the skin incision on corresponding lesions, a 5 mm small skin incision was placed on the medial side of the thigh was shifted toward the patellar tendon and injected into the IFP directly. To analyze the pain behavior quantitatively, incapacitance (weight bearing) test was performed before MIA injection and at days 1, 3, 5, 7, and 14 after MIA injection. Histochemical analyses of the knee joint were performed at days 7 and 14 after MIA injection. Results: Weight bearing of the MIA injected leg was significantly decreased between day 1 and 7 in both 0.2 and 1.0 mg groups. In the 0.2 mg group, this decrease was transient and significantly improved at day 7 and returned to the basal level at day 14. In contrast, weight bearing remained significantly decreased until day 14 in the 1.0 mg group (Fig. 1). Histological assessment indicated that significant numbers of the cells infiltrated around the blood vessels in the IFP at day 7 in both 0.2 and 1.0 groups. Thickening of the patellar tendon and extensive fibrosis and neovascularization in the IFP were observed more obviously at day 14 in the 1.0 mg group. Interestingly, little changes were observed in articular cartilage and synovial membrane in both groups (Fig. 2A and B). Immunohistochemical analyses indicated that the number of CGRP (Calcitonin gene related peptide) positive fibers was accumulated around the perivascular region and in the fibrous tissues in the IFP. At day 14, more numbers of the CGRP positive fibers were observed in the fibrotic region of the IFP in 1.0 mg group. Conclusions: Weight bearing was significantly reduced immediately after MIA injection. This suggests that acute inflammatory response of the IFP is important for inducing joint pain. Severe inflammatory response induced extensive neovascularization and fibrosis of the IFP after day 7. Since CGRP positive fibers were accumulated in these regions, we consider that neovascularization and fibrosis of the IFP induced by inflammatory response have critical roles in the prolongation of knee pain. Pain behavior correlates fibrosis and angiogenesis of the infrapatellar fat pad induced by monoiodoacetic acid.Fig. 2Histological examination of the knee stained with Hematoxylin and eosin (A), Safranin O (B).View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Articular Cartilage Degenerates After Subtotal/Total Lateral Meniscectomy but Radiographic Arthrosis Progression Is Reduced After Meniscal Transplantation

Background: Little is known about the degree of articular cartilage degeneration after subtotal/total lateral meniscectomy in patients who later undergo isolated lateral meniscal allograft transplantation (LMAT). It has not yet been studied whether arthritic changes as shown on radiographs were lower during the posttransplantation period than during the meniscus-deficient period. Hypothesis: Articular cartilage will significantly degenerate during the meniscus-deficient period, but the progression in radiographic arthrosis is reduced after LMAT. Study Design: Case series; Level of evidence, 4. Methods: This study retrospectively reviewed 49 patients who underwent subtotal/total lateral meniscectomy before isolated LMAT performed over 1 year later by the same surgeon. International Cartilage Repair Society (ICRS) grades of the femorotibial joint at the time of subtotal/total meniscectomy and at LMAT were compared. Radiographic evaluation was performed at the time of initial meniscectomy, LMAT, and the latest follow-up in 38 patients (after 11 patients whose radiographs showed incomplete ossification at the time of meniscectomy were excluded). Arthrosis, based on Kellgren-Lawrence (K-L) grades, was determined on standing anteroposterior views. Joint space width (JSW) was measured on weightbearing flexion posteroanterior views. Results: Over a mean meniscus-deficient period of 4.5 years (range, 1-13 years), articular cartilage significantly degenerated on the femoral and tibial sides (P < .001). Grade ≥3 degeneration on the lateral tibial plateau was observed in 13 patients (27%) at the time of initial meniscectomy; this incidence doubled to 28 patients (57%) by the time of LMAT. The K-L grades worsened (P < .001) and JSWs narrowed significantly (–0.65 ± 1.09 mm; P = .001) during the mean meniscus-deficient period of 3.1 years. At radiographic assessment, however, the K-L grades (P = .097) and JSWs (4.06 ± 1.19 vs 3.92 ± 1.21 mm; mean difference, –0.14 ± 0.68 mm; P = .213) did not significantly change during the mean posttransplantation period of 3.8 years. The changes in ICRS grade and JSW during the meniscus-deficient period were not associated with age, body mass index, mechanical axis deviation, or Tegner activity level (P > .05 for all relationships). Conclusion: Patients who underwent isolated LMAT showed substantial articular cartilage degeneration at the time of initial subtotal/total lateral meniscectomy, and this degeneration progressed thereafter. Further progression of radiographic arthrosis was delayed after LMAT.

Arthroscopic Validation of Radiographic Grading Scales of Osteoarthritis of the Tibiofemoral Joint

The purpose of this study was to use the Kellgren-Lawrence, Ahlback, and Brandt grading scales to correlate radiographic grade of osteoarthritis with the actual degree of articular cartilage degeneration within the tibiofemoral joint in patients with chronic knee pain. The study group consisted of 125 patients with symptomatic osteoarthritis of the tibiofemoral joint. For all patients, standing anteroposterior radiographs of the knee were obtained before arthroscopic knee surgery. Each articular surface of the tibiofemoral joint was graded at arthroscopy. Two radiologists retrospectively reviewed the knee radiographs without knowledge of the arthroscopic findings to determine the presence and severity of osteoarthritis of the tibiofemoral joint using the Kellgren-Lawrence, Ahlback, and Brandt grading scales. Correlation coefficients describing the relation between grade of osteoarthritis and severity of articular cartilage degeneration were calculated for each grading scale. The correlation coefficients for the Kellgren-Lawrence, Ahlback, and Brandt grading scales were 0.49, 0.41, and 0.56, respectively. The differences between the correlation coefficients for the Kellgren-Lawrence and Ahlback grading scales and the correlation coefficients for the Brandt and Ahlback grading scales were statistically significant (p < 0.05). Many patients with no radiographic findings of osteoarthritis had significant articular cartilage degeneration within the tibiofemoral joint. The Kellgren-Lawrence and Brandt grading scales were equally effective in defining the presence of and estimating the severity of osteoarthritis of the tibiofemoral joint but had only a moderately strong correlation with the actual degree of articular cartilage degeneration.

Subchondral thickness does not vary with cartilage degeneration on the metatarsal.

Osteoarthritis is a disease of synovial joints that involves articular cartilage breakdown with accompanying bone changes, including subchondral sclerosis and osteophytosis. However, conflicting data have been reported concerning the cause-and-effect relationship, if any, between these changes. The authors studied the subchondral plate (subchondral bone plus calcified cartilage) in relation to the degree of articular cartilage degeneration on the distal articular surface of the first metatarsal, a region prone to osteoarthritis. No correlation was found between subchondral plate thickness or porosity and the degree of cartilage degeneration in the study sample of 96 metatarsals. Owing to the suggestion that initiation of cartilage fibrillation may be a result of steep stiffness gradients in the subchondral bone, the ratios of subchondral plate thickness in adjacent regions of the metatarsal head were examined in detail, but no correlation was found with subchondral degeneration. Thus increases in subchondral bone thickness are not associated with increases in cartilage degeneration on the first metatarsal, which may imply that subchondral bone changes do not cause osteoarthritis in this joint.

The Effect of Total Meniscectomy versus Caudal Pole Hemimeniscectomy on the Stifle Joint of the Sheep

SummaryTotal medial meniscectomy and caudal pole hemimeniscectomy were performed on the stifle joints of twelve sheep. The two forms of meniscectomy produced a comparable degree of postoperative lameness that resolved within two weeks of the operations. After six months the sheep were euthanatised and the stifle joints examined. Fibrous tissue that replaced the excised meniscus in the total meniscectomy group did not cover as much of the medial tibial condyle as the residual cranial pole and caudal fibrous tissue observed following hemimeniscectomy. The articular cartilage from different regions within the joints was examined for gross and histological evidence of degeneration. Analyses of the articular cartilage for water content, glycosaminoglycan composition and DNA content were performed. The proteoglycan synthesis and release from explanted articular cartilage samples in tissue culture were also measured. There were significant pathological changes in the medial compartment of all meniscectomised joints. The degree of articular cartilage degeneration that was observed following total meniscectomy and caudal pole meniscectomy was similar. Caudal pole hemimeniscectomy, involving transection of the meniscus, causes the same degree of degeneration of the stifle joint that occurs following total meniscectomy.The effect of total medial meniscectomy versus caudal pole hemimeniscectomy on the stifle joint of sheep was studied experimentally. Six months after the operations gross pathology, histopathology, cartilage biochemical analysis and the rate of proteoglycan synthesis in tissue culture were used to compare the articular cartilage harvested from the meniscectomised joints. Degeneration of the articular cartilage from the medial compartment of the joints was present in both of the groups. Caudal pole hemimeniscectomy induces a comparable degree of articular cartilage degeneration to total medial meniscectomy in the sheep stifle joint.

Revision anterior cruciate ligament surgery: experience from Miami.

Failed anterior cruciate ligament reconstruction as defined by recurrent patholaxity is increasingly commonplace. This report presents the findings of 54 patients who had unsuccessful intraarticular anterior cruciate ligament reconstruction to correct persistent instability and who subsequently underwent revision anterior cruciate ligament surgery. Before revision, patients were evaluated by clinical examination, KT-1000 arthrometer, radiographs, Lysholm knee score, Tegner activity scale, and subjective questionnaire. The results were compared at a mean of 32 months following revision surgery. There was an average of 16 months from index procedure to the time of revision. Autogenous patellar tendon grafts were used in 61% of the cases with 30% of these harvested from the contralateral knee. Fresh frozen patellar tendon was used in 35% and autogenous hamstring tendons in 4%. Revision was successful in objectively improving stability in all patients with an average KT-000 of 2.8 mm. Autogenous tissue grafts provided greater objective stability when compared with allograft tissue with average KT-1000 of 2.2 and 3.3, respectively. Functionally, however, there was no significant difference in outcome between the 2 groups. Harvesting of the contralateral patellar tendon was found to have no adverse long term effect. Subjectively, the results were significantly worse depending on the degree of articular cartilage degeneration. Only 54% of patients returned to their preanterior cruciate ligament injury activity level. Competence in various anterior cruciate ligament reconstruction techniques will facilitate revision surgery especially in avoiding preexisting tunnels and hardware. Correct graft placement and addressing the secondary restraints are critical to successful revision surgery.

Arthroscopic partial medial meniscectomy in patients over 40 years old: a 5- to 11-year follow-up study.

A retrospective analysis of 68 knees from 65 patients older than 40 years, who had undergone a partial medial meniscectomy, was carried out. The average age of the patients was 49.7 years (range, 40 to 74), and the mean follow-up period was 7.8 years (range, 5 to 11). The patients were divided into two groups based on the degree of articular cartilage degeneration. Group I consisted of 53 knees that did not have any significant articular cartilage damage beyond grade I or II. Group II consisted of 15 knees that had grade III or IV cartilage damage. Overall, excellent results were obtained in 44 patients (47 knees), good results in 10 patients, fair results in six patients, and poor results in five patients. In group I, 46 knees (87%) had an excellent outcome, and only one patient had a poor result. In contrast, patients in group II had significantly worse results, with only one knee (7%) having excellent outcome, and four knees had a poor result. A specific history of trauma did not affect the clinical outcome. Forty-two patients (64%) were able to resume normal athletic activities without any restrictions. Arthroscopic partial medial meniscectomy in patients older than 40 years is an acceptable and effective long-term treatment, particularly in patients without significant articular cartilage damage.