Femorotibial Joint Research Articles

Rat Model of Intra-articular Chondrocyte Xenotransplantation.

Current treatment options are not providing an adequate solution for cartilage defects. Articular cartilage lesions in particular are not able to repair spontaneously and progressively degenerate with an arthrosic pattern. Aiming to solve this pressing medical need, xenotransplantation of porcine chondrocytes could be developed as a new therapeutic approach. Xenotransplantation is gaining much attention, thanks to the advances in animal genetic engineering and progress in the characterization of the rejection mechanisms that prevent long-term graft survival. In this regard, our team has identified various targets for intervention that should be tested in a meaningful animal model to prove their relevance in rejection of xenogeneic cartilage. To this end, we have recently established a discordant xenotransplantation model by injecting three million porcine articular chondrocytes (PAC) into the femorotibial joint of Lewis rats. This chapter describes this new model, which can be used to assess the immunoregulatory effect of a variety of strategies designed to inhibit rejection of xenogeneic PAC both at the humoral and cellular levels.

Chondromalacia of the cranial medial femoral condyle; its occurrence and association with clinical outcome in a population of adult horses with stifle lameness.

Chondromalacia of the cranial medial femoral condyle (CMFC) is a potential cause of stifle lameness in adult horses. However, there is scant published evidence of either its occurrence or its clinical significance. To document the occurrence of CMFC seen during diagnostic arthroscopy in adult horses with stifle lameness and to investigate its prognostic significance. Retrospective cohort study. The records were reviewed of all horses with unilateral or bilateral lameness localised to the stifle that underwent diagnostic arthroscopy of the cranial medial femorotibial joint at a UK equine hospital. The surgical findings were noted from each. Case outcomes were determined by unstructured telephone discussions with owners. A satisfactory outcome was defined as a horse that was in ridden work without ongoing anti-inflammatory medication. Multivariable logistic regression was used to create a model with an outcome time point at 12-month post-operatively. One hundred and four horses were included in the study. CMFC was found in 79. In 25 CMFC was the only finding, 54 horses had CMFC plus other pathology and 25 had other pathology, but no CMFC. At 12months, horses with CMFC were 9.9 (95% CI 2.2-45.0, P<0.01) times more likely to have an unsatisfactory outcome than horses without CMFC. The study relied on retrospective analysis of clinical notes and archived arthroscopy videos. Assessment of outcome was determined by unstructured telephone interview and therefore there is potential for reporting errors to exist. CMFC is a common arthroscopic finding in horses with stifle lameness and is significantly associated with an increased likelihood of the horse not being in ridden work at long-term follow-up.

Femorotibial kinematics in dogs treated with tibial plateau leveling osteotomy for cranial cruciate ligament insufficiency: An in vivo fluoroscopic analysis during walking.

To determine the ability of tibial plateau leveling osteotomy (TPLO) to address abnormal femorotibial kinematics caused by cranial cruciate ligament (CCL) rupture during walking in dogs. Prospective, clinical. Sixteen dogs (20-40 kg) with unilateral complete CCL rupture. Lateral view fluoroscopy was performed during treadmill walking preoperatively and 6 months after TPLO. Digital three-dimensional (3D) models of the femora and tibiae were created from computed tomographic (CT) images. Gait cycles were analyzed by using a 3D-to-2D image registration process. Craniocaudal translation, internal/external rotation, and flexion/extension of the femorotibial joint were compared between preoperative and 6-month postoperative time points for the affected stifle and 6-month postoperative unaffected contralateral (control) stifles. In the overall population, CCL rupture resulted in 10 ± 2.2 mm (mean ± SD) cranial tibial translation at midstance phase, which was converted to 2.1 ± 4.3 mm caudal tibial translation after TPLO. However, five of 16 TPLO-treated stifles had 4.1 ± 0.3 mm of cranial tibial subluxation during mid-to-late stance phase, whereas 10 of 16 TPLO-treated stifles had 4.3 ± 0.4 mm of caudal tibial subluxation throughout the gait cycle. Overall, postoperative axial rotational and flexion/extension patterns were not different from control, but stifles with caudal tibial subluxation had more external tibial rotation during mid-to-late stance phase compared with stifles with cranial tibial subluxation. TPLO mitigated abnormal femorotibial kinematics but did not restore kinematics to control values in 15 of 16 dogs during walking. Tibial plateau leveling osteotomy reduces cranial tibial subluxation during walking, but persistent instability is common.

TL 18209 - Relationship between the knee and hindfoot axes among patients with advanced gonarthrosis

Introduction: The relationship between knee and hindfoot alignment is intuitive, but the number of studies on associated deformities remains limited. The objective of this study is to assess the correlation between the femorotibial joint axis and the hindfoot axis in patients with advanced gonarthrosis. Methods: The knee and hindfoot axes were assessed in 72 patients with indications for total knee replacement. Knee radiographs and long axial view radiographs of the hindfoot were acquired from all patients. The hindfoot/ankle function of the patients was assessed using the American Orthopedic Foot and Ankle Society (AOFAS) scale. Statistical analysis was performed at a maximum significance level of 5%. Results: The sample included 24 (33.3%) men and 48 (66.7%) women with a mean age of 58.7 years. The results showed that 79.2% subjects had genu varum (mean: 15º±7.69), and 20.8% had genu valgum (mean: 15.9º) (p&gt;0.05); 46 (63.89%) patients had hindfoot varus (mean: 8.5º±6.07), and 26 (36.11%) had hindfoot valgus (mean: 3.9º±3.92). We observed a significant association between the knee and hindfoot axes (p&lt;0.05). There was no significant correlation only between genu valgum–hindfoot varus (p&lt;0.05). The mean AOFAS score was 74.26 points, with significantly higher scores among patients with hindfoot varus. The AOFAS score was correlated with the hindfoot and knee axes (P&lt;0.05). Conclusion: The knee and hindfoot axes were associated in patients with advanced gonarthrosis. In addition, the patients with hindfoot varus showed better ankle function according to the AOFAS score.

Jumping and Grasping: Universal Locking Mechanisms in Insect Legs

AbstractThickened femora of insects are correlated to enlarged muscle masses and serve two basic purposes: jumping/kicking and grasping/holding. Modifications on the ventral femoral wall and the tibial flexor tendon that are possibly involved in catch mechanisms have been described in multiple insect taxa with both jumping and grasping legs. Our comparative study aims to explore the functional and structural similarities of these modification in jumping and grasping leg types from Coleoptera, Hymenoptera, Diptera, and Orthoptera with the combination of cutting edge, noninvasive imaging methods, and classical dissections techniques. Our data indicate that locking mechanisms are present in the jumping and grasping legs of insects. We describe three femoro-tibial lock types based on the location of the interacting sclerites relative to the site of origin of the tibial flexor tendon. All of the three types can be found in jumping insect legs, whereas only one type is present in grasping legs. The locking mechanism might aid in keeping the femoro-tibial joint in a flexed position for an extended period of time. Our data indicate that morphologically similar modifications in the femoro-tibial joint are involved in energy-saving mechanisms both in jumping and grasping legs in insects.

Facteurs radiologiques et IRM de bilatéralité devant une lésion symptomatique sur ménisque discoïde latéral

BackgroundThe incidence of bilateral discoid lateral meniscus (DLM) is as high as 73 to 85%, and associated contralateral meniscus tears ranged from 4 to 33% in symptomatic surgical DLM. The goal of the study was analyzing the factors that predict contralateral presence and tearing of DLM in patients who underwent surgery for symptomatic DLM. Our hypothesis was that there is a significant correlation between operative DLM properties and the incidence of bilateral DLM with associated contralateral meniscus tears. These properties include tear patterns, younger patient age, and characteristic X-ray findings. Patients and methodsThis prospective study included 76 patients who underwent arthroscopic surgery for symptomatic DLM. The contralateral knees were evaluated with X-ray and MRI. Based on the MRI findings, DLM was categorized into three types, and tear patterns were analyzed. The characteristic X-ray findings were evaluated as follows: (1) high fibular head, (2) squared-off appearance of the lateral femoral condyle, (3) cupping of the lateral tibial plateau, (4) widened femorotibial joint space, (5) hypoplasia of the lateral intercondylar spine, (6) notching of the LFC. The number of characteristic X-ray findings (0/1/more than 2) was noted. Binary logistic analysis was performed to find the factors that predict the presence and tear of contralateral DLM. ResultsMRI of contralateral knees revealed 43 cases (57%) of complete DLM, 25 cases (33%) of incomplete DLM, and 8 cases (11%) of normal meniscus. Meniscus tears were found in 29 cases (38%) in the contralateral knee. X-ray of the contralateral knee revealed that 27 patients (36%) had one and 24 patients (32%) had two or more characteristic X-ray findings. On logistic regression analysis, the associations between contralateral knee meniscal tear and the presence of one or more than two characteristic X-ray findings were statistically significant (OR: 16.5, p=0.028; OR: 264.0, p=0.000, respectively). DiscussionThe number of characteristic X-ray findings in the contralateral knee is a significant predictive factor for contralateral DLM type and/or tear. Symptomatic DLM patients with characteristic X-ray findings should be carefully evaluated for contralateral DLM and meniscal tears. Level of evidenceIII, prospective diagnostic study of consecutive patients.

Factors associated with bilateral discoid lateral meniscus tear in patients with symptomatic discoid lateral meniscus tear using MRI and X-ray

BackgroundThe incidence of bilateral discoid lateral meniscus (DLM) is as high as 73 to 85%, and associated contralateral meniscus tears ranged from 4 to 33% in symptomatic surgical DLM. The goal of the study was analyzing the factors that predict contralateral presence and tearing of DLM in patients who underwent surgery for symptomatic DLM. Our hypothesis was that there is a significant correlation between operative DLM properties and the incidence of bilateral DLM with associated contralateral meniscus tears. These properties include tear patterns, younger patient age, and characteristic X-ray findings. Patients and MethodsThis prospective study included 76 patients who underwent arthroscopic surgery for symptomatic DLM. The contralateral knees were evaluated with X-ray and MRI. Based on the MRI findings, DLM was categorized into three types, and tear patterns were analyzed. The characteristic X-ray findings were evaluated as follows: (1) high fibular head, (2) squared-off appearance of the lateral femoral condyle, (3) cupping of the lateral tibial plateau, (4) widened femorotibial joint space, (5) hypoplasia of the lateral intercondylar spine, (6) notching of the LFC. The number of characteristic X-ray findings (0/1/more than 2) was noted. Binary logistic analysis was performed to find the factors that predict the presence and tear of contralateral DLM. ResultsMRI of contralateral knees revealed 43 cases (57%) of complete DLM, 25 cases (33%) of incomplete DLM, and 8 cases (11%) of normal meniscus. Meniscus tears were found in 29 cases (38%) in the contralateral knee. X-ray of the contralateral knee revealed that 27 patients (36%) had one and 24 patients (32%) had two or more characteristic X-ray findings. On logistic regression analysis, the associations between contralateral knee meniscal tear and the presence of one or more than two characteristic X-ray findings were statistically significant (OR: 16.5, p=0.028; OR: 264.0, p=0.000, respectively). DiscussionThe number of characteristic X-ray findings in the contralateral knee is a significant predictive factor for contralateral DLM type and/or tear. Symptomatic DLM patients with characteristic X-ray findings should be carefully evaluated for contralateral DLM and meniscal tears. Level of evidenceIII, prospective diagnostic study of consecutive patients.

Effect of Intra-Articular Sprifermin vs Placebo on Femorotibial Joint Cartilage Thickness in Patients With Osteoarthritis

Sprifermin is under investigation as a disease-modifying osteoarthritis drug. To evaluate the effects of sprifermin on changes in total femorotibial joint cartilage thickness in the more symptomatic knee of patients with osteoarthritis. FORWARD (FGF-18 Osteoarthritis Randomized Trial with Administration of Repeated Doses) was a 5-year, dose-finding, multicenter randomized clinical trial conducted at 10 sites. Eligible participants were aged 40 to 85 years with symptomatic, radiographic knee osteoarthritis and Kellgren-Lawrence grade 2 or 3. Enrollment began in July 2013 and ended in May 2014; the last participant visit occurred on May 8, 2017. The primary outcome at 2 years and a follow-up analysis at 3 years are reported. Participants were randomized to 1 of 5 groups: intra-articular injections of 100 μg of sprifermin administered every 6 months (n = 110) or every 12 months (n = 110), 30 μg of sprifermin every 6 months (n = 111) or every 12 months (n = 110), or placebo every 6 months (n = 108). Each treatment consisted of weekly injections over 3 weeks. The primary end point was change in total femorotibial joint cartilage thickness measured by quantitative magnetic resonance imaging at 2 years. The secondary end points (of 15 total) included 2-year change from baseline in total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. The minimal clinically important difference (MCID) is unknown for the primary outcome; for total WOMAC score in patients with hip and knee osteoarthritis, the absolute MCID is 7 U (95% CI, 4 to 10 U) and the percentage MCID is 14% (95% CI, 9% to 18%). Among 549 participants (median age, 65.0 years; 379 female [69.0%]), 474 (86.3%) completed 2-year follow-up. Compared with placebo, the changes from baseline to 2 years in total femorotibial joint cartilage thickness were 0.05 mm (95% CI, 0.03 to 0.07 mm) for 100 μg of sprifermin administered every 6 months; 0.04 mm (95% CI, 0.02 to 0.06 mm) for 100 μg of sprifermin every 12 months; 0.02 mm (95% CI, -0.01 to 0.04 mm) for 30 μg of sprifermin every 6 months; and 0.01 mm (95% CI, -0.01 to 0.03 mm) for 30 μg of sprifermin every 12 months. Compared with placebo, there were no statistically significant differences in mean absolute change from baseline in total WOMAC scores for 100 μg of sprifermin administered every 6 months or every 12 months, or for 30 μg of sprifermin every 6 months or every 12 months. The most frequently reported treatment-emergent adverse event was arthralgia (placebo: n = 46 [43.0%]; 100 μg of sprifermin administered every 6 months: n = 45 [41.3%]; 100 μg of sprifermin every 12 months: n = 50 [45.0%]; 30 μg of sprifermin every 6 months: n = 40 [36.0%]; and 30 μg of sprifermin every 12 months: n = 48 [44.0%]). Among participants with symptomatic radiographic knee osteoarthritis, the intra-articular administration of 100 μg of sprifermin every 6 or 12 months vs placebo resulted in an improvement in total femorotibial joint cartilage thickness after 2 years that was statistically significant, but of uncertain clinical importance; there was no significant difference for 30 μg of sprifermin every 6 or 12 months vs placebo. Durability of response also was uncertain. ClinicalTrials.gov Identifier: NCT01919164.

En guise d’introduction…

The incidence of bilateral discoid lateral meniscus (DLM) is as high as 73 to 85%, and associated contralateral meniscus tears ranged from 4 to 33% in symptomatic surgical DLM. The goal of the study was analyzing the factors that predict contralateral presence and tearing of DLM in patients who underwent surgery for symptomatic DLM. Our hypothesis was that there is a significant correlation between operative DLM properties and the incidence of bilateral DLM with associated contralateral meniscus tears. These properties include tear patterns, younger patient age, and characteristic X-ray findings.This prospective study included 76 patients who underwent arthroscopic surgery for symptomatic DLM. The contralateral knees were evaluated with X-ray and MRI. Based on the MRI findings, DLM was categorized into three types, and tear patterns were analyzed. The characteristic X-ray findings were evaluated as follows: (1) high fibular head, (2) squared-off appearance of the lateral femoral condyle, (3) cupping of the lateral tibial plateau, (4) widened femorotibial joint space, (5) hypoplasia of the lateral intercondylar spine, (6) notching of the LFC. The number of characteristic X-ray findings (0/1/more than 2) was noted. Binary logistic analysis was performed to find the factors that predict the presence and tear of contralateral DLM.MRI of contralateral knees revealed 43 cases (57%) of complete DLM, 25 cases (33%) of incomplete DLM, and 8 cases (11%) of normal meniscus. Meniscus tears were found in 29 cases (38%) in the contralateral knee. X-ray of the contralateral knee revealed that 27 patients (36%) had one and 24 patients (32%) had two or more characteristic X-ray findings. On logistic regression analysis, the associations between contralateral knee meniscal tear and the presence of one or more than two characteristic X-ray findings were statistically significant (OR: 16.5, p = 0.028; OR: 264.0, p = 0.000, respectively).The number of characteristic X-ray findings in the contralateral knee is a significant predictive factor for contralateral DLM type and/or tear. Symptomatic DLM patients with characteristic X-ray findings should be carefully evaluated for contralateral DLM and meniscal tears.III, prospective diagnostic study of consecutive patients.

MRI diagnosis in multiligamentous injuries of knee with associated dislocations and neurovasacular sequelae: a retrospective analysis of injury patterns

BackgroundSimultaneous injury of two or more knee ligaments with concurrent tears involving the anterior cruciate and medial collateral ligaments is considered to be associated with femorotibial knee dislocations (KD). The purpose of this study is to characterize multiligamentous knee injury patterns associated with dislocations on MRI and to describe the incidence of their sequelae such as tibial plateau fractures, peroneal nerve injuries, and posterolateral corner (PLC) injuries.Participants and methodsAfter obtaining institutional ethical committee approval, we retrospectively identified 108 multiligamentous knee injuries in 100 patients who met with trauma and were treated at our tertiary care center between April 2014 and December 2018. Descriptive statistics were reported using numbers and percentages for categorical variables in cases of multiligamentous injuries, ipsilateral tibial plateau fractures, ipsilateral femoral fractures, peroneal nerve injury, arterial injury, compartment syndrome, and PLC injuries.ResultsThe most common (39.8%) injury pattern was a combined disruption of the anterior cruciate ligament, posterior cruciate ligament, and PLC. Schenck KD III-M was the most common injury type in KD, constituting 16.7%. Medial-sided injuries were the most common injury patterns seen with KD. There was a significant risk of peroneal nerve injury with lateral-sided injuries.ConclusionKD, though rare, may have devastating clinical sequelae such as compartment syndrome if not recognized and treated. Therefore, it is necessary to recognize imaging findings of femorotibial joint dislocations and associated injuries to the adjacent neurovascular bundles.

Body side-specific changes in sensorimotor processing of movement feedback in a walking insect.

Feedback from load and movement sensors can modify timing and magnitude of the motor output in the stepping stick insect. One source of feedback is stretch reception by the femoral chordotonal organ (fCO), which encodes such parameters as the femorotibial (FTi) joint angle, the angular velocity, and its acceleration. Stimulation of the fCO causes a postural resistance reflex, during quiescence, and can elicit the opposite, so-called active reaction (AR), which assists ongoing flexion during active movements. In the present study, we investigated the role of fCO feedback for the difference in likelihood of generating ARs on the inside vs. the outside during curve stepping. We analyzed the effects of fCO stimulation on the motor output to the FTi and the neighboring coxa-trochanter and thorax-coxa joints of the middle leg. In inside and outside turns, the probability for ARs increases with increasing starting angle and decreasing stimulus velocity; furthermore, it is independent of the total angular excursion. However, the transition between stance and swing motor activity always occurs after a specific angular excursion, independent of the turning direction. Feedback from the fCO also has an excitatory influence on levator trochanteris motoneurons (MNs) during inside and outside turns, whereas the same feedback affects protractor coxae MNs only during outside steps. Our results suggest joint- and body side-dependent processing of fCO feedback. A shift in gain may be responsible for different AR probabilities between inside and outside turning, whereas the general control mechanism for ARs is unchanged.NEW & NOTEWORTHY We show that parameters of movement feedback from the tibia in an insect during curve walking are processed in a body side-specific manner, and how. From our results it is highly conceivable that the difference in motor response to the feedback supports the body side-specific leg kinematics during turning. Future studies will need to determine the source for the inputs that determine the local changes in sensory-motor processing.

Finite Element Modelling Simulated Meniscus Translocation and Deformation during Locomotion of the Equine Stifle.

Simple SummaryMeniscal tears are one of the most common soft tissue injuries in the equine stifle joint. To date no optimal treatment strategy to heal meniscal tissue is available. Accordingly, there is a need to improve treatment for meniscal injuries and thus to identify appropriate translational animal models. A possible alternative to animal experimentation is the use of finite element modelling (FEMg). FEMg allows simulation of time dependent changes in tissues resulting from biomechanical strains. We developed a finite element model (FEM) of the equine stifle joint to identify pressure peaks and simulate translocation and deformation of the menisci at different joint angles under loading conditions. The FEM model was tested across a range of motion of approximately 30°. Pressure load was higher overall in the lateral meniscus than in the medial meniscus. Accordingly, the simulation showed higher translocation and deformation throughout the whole range of motion in the lateral compared to the medial meniscus. The results encourage further refinement of this FEM model for studying loading patterns on menisci and articular cartilages as well as the resulting mechanical stress in the subchondral bone. A functional FEM model can not only help identify segments in the femoro–tibial joint which are predisposed to injury, but also provide better understanding of the progression of certain stifle disorders, simulate treatment/surgery effects and to optimize implant/transplant properties in order to most closely resemble natural tissue. We developed a finite element model (FEM) of the equine stifle joint to identify pressure peaks and simulate translocation and deformation of the menisci. A series of sectional magnetic resonance images (1.5 T) of the stifle joint of a 23 year old Shetland pony gelding served as basis for image segmentation. Based on the 3D polygon models of femur, tibia, articular cartilages, menisci, collateral ligaments and the meniscotibial ligaments, an FEM model was generated. Tissue material properties were assigned based on data from human (Open knee(s) project) and bovine femoro-tibial joint available in the literature. The FEM model was tested across a range of motion of approximately 30°. Pressure load was overall higher in the lateral meniscus than in the medial. Accordingly, the simulation showed higher translocation and deformation in the lateral compared to the medial meniscus. The results encourage further refinement of this model for studying loading patterns on menisci and articular cartilages as well as the resulting mechanical stress in the subchondral bone (femur and tibia). A functional FEM model can not only help identify segments in the stifle which are predisposed to injury, but also to better understand the progression of certain stifle disorders, simulate treatment/surgery effects and to optimize implant/transplant properties.

Development of an Impulse Response Method for Assessing Knee Osteoarthritis at the Femorotibial Joint: Comparison Between Healthy Young Adults and Older Women with Clinical Knee Osteoarthritis

Because in patients with knee osteoarthritis (OA), the knee joint properties such as cartilage, meniscus, soft tissue and bone formation are assumed to degeneration change, the shock absorb might also decrease. The transmission of impulse from femur and tibia is thought to change in the knee joint. The purpose of the present study was to determine the differences between young healthy women and elderly women with knee OA using the impulse response method. Twenty-six older women with clinically diagnosed knee OA (OA group, age: 69 ± 6 years) and 26 young women without knee OA (young control [YC] group, age: 21 ± 1 years) participated in the study. The OA group fulfilled the knee OA classification criteria based on clinical findings. An input device provided an impulse to the subject while standing. The output value was measured using a single-axis accelerometer. The outcome measures were the input–output ratio and power spectrum. The input–output ratio did not significantly differ between the groups. The power spectrum at 21–30 Hz was significantly greater (p = 0.036) in the OA group than in the control group. Additionally, the power spectrum at 21–30 Hz correlated with knee pain (r = 0.39, p = 0.049). At 21–30 Hz, transmission of impulse from femur and tibia in the knee joint was lower in the OA group than in the control group. The IR method used in the present study could detect the transmission of impulse in early knee OA.

Radiographic study of the development of the pelvis and hip and the femorotibial joints in domestic cats.

The aims of the present study were to monitor, by radiographic examination, the skeletal development of the pelvis and the femorotibial joints of the domestic cat from the first week of life until the closing of the growth plates. Radiographic examinations were collected from 15 domestic cats at weekly intervals during the first month and every 2 weeks from the second to the fourth month of age. After that, examinations were performed monthly until the age of 18 months. The ischiopubic growth plate closed at 2 months of age, followed by the fusion of the iliopubic, ilioischial, proximal femoral, greater trochanter and proximal fibular growth plates. The distal femur and proximal tibial growth plates were the last to close, with fusion occurring at 18 months. The mean time to closure of the iliopubic, ilioischial and distal femoral growth plates was shorter in females. The ossification centers first appeared, in ascending order, beginning with the lesser trochanter, followed by the greater trochanter, proximal fibular epiphysis, tibial tuberosity, patella, ischial tuberosity and lateral sesamoid of the popliteus muscle. The complete closure of the growth plates of domestic cats occurs at approximately 18 months of age. Skeletal maturation at approximately 18 months of age is an important parameter to be considered in radiographic evaluation of certain skeletal changes, evolution of fractures and nutritional imbalance.

Correlation of serum and synovial leptin concentrations with body condition scores in healthy and osteoarthritic dogs.

To evaluate the relationship between serum and synovial fluid (SF) leptin concentrations and body condition score (BCS) in healthy and osteoarthritic dogs. Controlled, prospective, clinical study. Nineteen healthy dogs and 29 dogs with osteoarthritis (OA) secondary to cranial cruciate ligament injury. Synovial fluid was obtained from the femorotibial joint under sedation (healthy dogs) or during surgery (OA dogs). Serum and SF leptin and interleukin (IL)-1β concentrations were measured via enzyme-linked immunosorbent assay. Dogs were classified as optimal weight (BCS 4-5/9) or overweight (BCS >5/9). Radiographs were scored for OA severity by a radiologist. Owners completed the Liverpool Osteoarthritis in Dogs (LOAD) questionnaire. Mean (± SD) SF leptin (4.09 ± 4 ng/mL) was lower than serum leptin (6.88 ± 5.52 ng/mL, P < .0001). Synovial fluid leptin was higher in overweight (5.28 ± 4.21) than in optimal body weight dogs (1.54 ± 1.72 ng/mL, P < .0001). Serum (P < .001) and SF leptin (P = .004) concentrations were associated with BCS. Concentration of SF leptin did not differ between healthy (2.4 ± 2.04 ng/mL) and OA (4.9 ± 4.3 ng/mL, P = .25) dogs. Synovial fluid leptin and LOAD scores were weakly associated (P = .03). No association was detected between SF leptin and radiographic score or IL-1β (P = .73). Serum and SF leptin correlated with BCS in this population. Synovial fluid leptin was weakly associated with LOAD scores but not with radiographic severity of OA or IL-1β. Serum and SF leptin concentrations do not predict radiographic severity of canine OA but contribute to joint pain and dysfunction.

Ultrasonography of the stifle

Stifle injuries are increasingly recognised as a major cause of hind limb lameness and commonly affect the soft tissues of the joint in adult horses, making ultrasonography a vital part of diagnostic imaging of this joint. This article aims to provide an introduction to stifle ultrasonography. To ensure comprehensive evaluation of the stifle, a systematic approach is necessary. The ultrasonographic examination is divided into five approaches: initially weight-bearing scans should be obtained of the cranial aspect (for the femoropatellar joint), medial aspect (for the medial femorotibial joint), and lateral aspect (for the lateral femorotibial joint), followed by flexed views from cranial (for the cranial aspect of the femorotibial joints) and, finally, in limited cases because pathology is rarer and the technique more demanding, weight-bearing views of the caudal aspect (for the caudal parts of both femorotibial joints). For the femoropatellar joint, ultrasound can be used to identify bruising (haematoma), injuries to the patellar ligaments, trochlear ridges (including osteochondrosis), and patella and tibial crest fractures. For the femorotibial joints, injuries to the menisci are the most common, but ultrasound can also identify rarer collateral and cruciate ligament injuries. and abnormalities of the weight-bearing surfaces of the femoral condyles, such as cartilage damage and subchondral bone cysts.

Short link N acts as a disease modifying osteoarthritis drug.

Osteoarthritis (OA) is a degenerative joint disease characterised by a progressive degradation of articular cartilage and underlaying bone and is associated with pain and disability. Currently, there is no medical treatment to reverse or even retard OA. Based on our previous reports, where we establish the repair potential of short Link N (sLN) in the intervertebral disc, a cartilage-like tissue, we hypothesise that sLN may hold similar promises in the repair of articular cartilage. This study aimed to determine if sLN, could prevent OA disease progression. Skeletally mature New Zealand white rabbits underwent unilateral anterior cruciate ligament transection (ACLT) of their left femorotibial joints to induce joint degeneration typical of OA. Beginning 3 weeks post-operatively, and every three weeks thereafter for 12 weeks, either saline (1 mL) or sLN (100 μg in 1 mL saline) was injected intraarticularly into the operated knee. Six additional rabbits underwent sham surgery but without ACLT or post-operative injections. The effects on gross joint morphology and cartilage histologic changes were evaluated. In the Saline group, prominent erosion of articular cartilage occurred in both femoral condyle compartments and the lateral compartment of the tibial plateau while, sLN treatment reduced the severity of the cartilage damage in these compartments of the knee showing erosion. Furthermore, statistically significant differences were detected between the joint OA score of the saline and sLN treated groups (p = 0.0118). Therefore, periodic intraarticular injection of sLN is a promising nonsurgical treatment for preventing or retarding OA progression, by reducing cartilage degradation.

Impact of contralateral radiographic status on longitudinal change of cartilage transverse relaxation time (T2) in radiographically normal knees, a model of early OA? – data from the osteoarthritis initiative

Purpose: Evaluating treatment for modifying structural progression at an early stage of OA requires models that display subtle synovial tissue alterations that occur early in the disease process, but still have a reasonable likelihood of progression. We have previously shown that radiographically normal (KLG0) knees with definite contralateral (CL) radiographic OA had a greater likelihood of incident ROA, and that KLG0 knees with CL radiographic joint space narrowing (JSN) displayed greater cartilage loss than those with radiographically normal CL knees. The purpose of this study was to use this model of “early” OA of a KLG0 case knee in a person with CL (non-posttraumatic) ROA, to determine whether baseline values and longitudinal change in cartilage composition differ compared with those with radiographically normal CL knees (controls). Methods: The data were obtained from the Osteoarthritis Initiative (OAI). 150 KLG0 case knees displayed CL ROA (KLG2-4; central readings vs.0.7), without reporting previous injury to that knee. Of those, 63 (50.8% female, age: 64.2±8.8 y, BMI: 27.6±4.4 kg/m2) were right knees with multi-echo spin-echo (MESE) MRIs (Fig.1) to support analysis of the cartilage transverse relaxation time (T2), a method previously shown to be related to cartilage composition and mechanical properties. 23 were CL KLG2 without JSN, 22 KLG2 with JSN grade1, 13 KLG3, and 5 KLG 4. The 63 case knees were matched 1:1 with 63 KLG0 controls of persons who were bilaterally KLG0 and had the same sex, similar age (64.3±8.7 y), and BMI (27.3±4.0 kg/m2). The 3-year change in cartilage T2 (between year 1 and 4 [Y1/4] follow-up) was determined from sagittal MESE MRIs (Fig.), analyzing the superficial and deep 50% of the cartilage in each of 16 femorotibial joint (FTJ) subregions. The mean T2-values across the superficial and deep cartilage layers of the entire FTJ were the primary analytic focus. Exploratory measures included T2 of the medial and lateral femorotibial compartment (MFTC/LFTC) and location-independent T2 shortening and lengthening scores (i.e. the sum of all negative / positive femorotibial subregion T2 changes). Results: The baseline T2 (Y1) was significantly greater in the case than in control KLG0 knees, both in the superficial and deep FTJ cartilage layers (paired t-test: p=0.01; Cohen’s D=0.40; and p=0.04; Cohen’s D=0.34, respectively). In the superficial layer, the effect tended to be stronger in the medial than in the lateral, and in the deep layer stronger in the lateral than in the medial compartment (Table 1).Table 1Cartilage T2 at the beginning of the observation intervalCase KLG0 kneesControl KLG0 kneesDifferenceSuperficial LayerMeanSD95% CIMeanSD95% CIPCohen DFTJ48.73.447.849.547.42.846.748.10.010.40MFTC49.24.248.150.347.73.746.848.60.020.37LFTC48.13.747.249.147.13.046.347.90.050.31Deep LayerFTJ37.72.337.238.337.02.036.537.50.040.34MFTC38.22.637.538.937.82.537.238.40.320.16LFTC37.32.636.637.936.22.235.736.80.010.44 Open table in a new tab When restricting analysis to those with CL JSN, the effect size (Cohen’s D) was 0.49 in the superficial and to 0.36 in the deep layer (data not shown). The longitudinal increase in medial and lateral T2 from Y1 to Y4 of the case knees was significantly different from zero; it also tended to be greater in case than in control KLG0 knees, but the case-control differences did not reach statistical significance (data not shown). Only when restricting the analysis to those with CL JSN, we observed a significantly (p<0.05) greater increase in deep layer T2 in the case than in the control knees in the FTJ, and also in the lateral compartment and location-independent lengthening score (Cohen’s D 0.45-0.46). No significant differences were observed in the longitudinal changes of the superficial layer (Table 2).Table 2Longitudinal change in T2 over 3 years of observationKLG0 with CL JSNKLG0 with CL KLG0DifferenceSuperficial LayerMeanSD95% CIMeanSD95% CIPCohen DFTJ1.01.90.41.60.91.50.41.40.850.04MFTC1.42.50.62.21.42.20.72.10.950.01LFTC0.62.2-0.21.30.41.9-0.21.00.820.06Decrease-15.316.1-20.4-10.1-15.110.2-18.4-11.80.96-0.01Increase31.717.726.037.429.717.824.035.40.610.11Deep LayerFTJ1.12.50.31.90.11.7-0.40.70.040.46MFTC1.33.30.22.40.32.4-0.41.10.140.34LFTC0.92.50.11.7-0.11.8-0.60.50.040.45Decrease-13.413.5-17.7-9.0-18.217.0-23.7-12.80.150.32Increase32.329.522.941.721.812.717.725.80.050.46 Open table in a new tab The increase in deep layer T2 was significantly correlated with location-independent measures of cartilage thickness loss in the FT joint (r=-0.27, p<0.01). Conclusions: This is the first study to explore whether cartilage T2 is sensitive to identifying compositional changes in cartilage in a model of “early” knee OA, i.e. a KLG0 knee with a CL non-posttraumatic ROA knee. Significant differences in superficial and deep layer cartilage T2 were observed at the beginning of the longitudinal observation interval. Similar to previous observations for the change in location-independent measures of cartilage thickness, significant longitudinal differences in T2 lengthening between case and control knees were observed in knees with CL JSN. These differences were limited to the deep layer, and were most prominent in the lateral femorotibial compartment. KLG0 knees with CL JSN hence may represent a model of early OA in which structure modification can be studied at an early disease stage.

Association of bone marrow lesions localisation with weight bearing pain in people with knee osteoarthritis: data from the osteoarthritis initiative

Purpose: Subchondral bone contributes to pain in knee osteoarthritis (OA). OA structural change particularly affects weight-bearing components of the joint, most notably the medial femorotibial compartment in people with varus angulation. Subchondral bone marrow lesions (BMLs) detected on MRI in knee OA are strongly associated with pain. BMLs typically occur in regions of the joint with the most severe structural change, for example, full-thickness cartilage lesions. However, the association between subchondral BMLs in weight-bearing components and weight-bearing pain has not been clarified. The purpose of this study was to assess association between BMLs location and weight bearing knee pain using data from the Osteoarthritis Initiative (OAI). We hypothesized that BMLs at the medial femorotibial joint compartment were associated with weight bearing pain, independent of non-weight bearing pain, and that changes in size of the BMLs over time were associated with change in weight bearing pain. Methods: The OAI is a publicly available multi-center, longitudinal, prospective observational study of knee OA. We examined the knees of OAI participants with MRI readings using the MRI Osteoarthritis Knee Score (MOAKS). BMLs, articular cartilage, osteophytes, Hoffa’s synovitis, effusion, meniscal morphology and anterior cruciate ligament tears were scored using the MOAKS, and femorotibial angle (FTA) and Body Mass Index (BMI) were examined. BML scores using MOAKS were available for 4 articular sub-regions (median and lateral femorotibial, and medial and lateral patellofemoral joint) and the subspinous region. Knee pain was assessed at baseline (cross-sectional) and baseline and 2 years (longitudinal) using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). We defined weight bearing pain as the sum of three WOMAC questions (pain on climbing stairs, on walking, and on standing) and non-weight bearing pain as the sum of two WOMAC questions (pain in bed and with sitting/lying down). Negative binomial regression was performed, using SPSS version 23 software. Results: 1412 participants were included in the cross-sectional analysis (from OAI project 22, 30 and 65), mean age 62 (±9) years, mean BMI 30 (±5), 61% female, median weight and non-weight bearing WOMAC score 2 (IQR 0, 4) and 0 (IQR 0, 1), and median total BML score 3 (IQR 1, 6). Weight bearing pain was associated with total BML score was r = 0.35 (p < 0.0001), and with BML scores at medial (r=0.29, p < 0.0001) and lateral (r=0.09, p = 0.0009) femorotibial joint compartments. Weight bearing pain was also associated with BML score at medial and lateral patellofemoral joint compartments (r = 0.03, p = 0.3 and 0.13, p < 0.0001, respectively). The association between weight bearing pain and BML scores at medial femorotibial and lateral patellofemoral joint compartments remained significant after adjusting for non-weight bearing pain, age, sex, BMI, FTA, BML scores at the other 4 joint compartments and the other OA related MRI features (osteophyte score, cartilage defect score, medial meniscus extrusion, anterior cruciate ligament tears, synovitis and effusion) (Table 1). 600 participants were included in the longitudinal study (OAI project 22), mean age 62 (± 9) years, mean BMI 31 (± 5), 57% female, median weight and non-weight bearing WOMAC score 1 (IQR 0, 3) and 0 (IQR 0, 1), and median total BML score 3 (IQR 2, 5). From baseline to 2 years, the changes in the mean weight and non-weight bearing 0.5 (±2.2) and 0.1 (±1.4), and mean total BML score were 0.7 (±1.9). The correlation between changes in weight bearing pain and changes in total BML score was r = 0.13 (p = 0.002); between changes in weight-bearing pain and BML score at medial and lateral femorotibial joint compartment were r = 0.16 (p < 0.0001) and -0.03 (p = 0.45), between changes in weight-bearing pain and changes in BML score at medial and lateral patellofemoral joint compartment were r = 0.04 (p = 0.3) and -0.03 (p = 0.5). The association between the changes in BML score at medial femorotibial joint compartment and changes in weight-bearing pain remained significant after adjusting for changes in non-weight bearing pain, age, sex, BMI, BML change at the other four joint compartments and osteophyte score change (Table 2). Conclusions: In this cross sectional and longitudinal study, BMLs at medial femorotibial joint compartment in varus knee OA participants were highly associated with the severity and the change in severity of weight bearing pain. The associations persisted when mutually adjusting for other feature of OA related MRI features, and adjusting for non-weight bearing pain, age, sex and BMI. Our findings suggest that BMLs in weight-bearing areas might contribute to weight bearing pain. Reducing BMLs or weight bearing in joint compartments with BMLs are candidate treatment targets in knee OA.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Is proximal fibular osteotomy a boon or bane for medial compartment osteoarthritis? - Our experience

Objective: To evaluate the functional and radiological outcome in medial compartment osteoarthritic knee treated with proximal fibular osteotomy as a new modality of treatment.Materials and Methods: Fifteen patients (10 men and 5 women, age range between 50-68 years) from May 2016 to May 2018 who had undergone proximal fibular osteotomy for medial compartment osteoarthritis knee were followed prospectively. Pre-operative and post-operative weight bearing scan gram obtained to analyse the alignment of lower limb (Femoro tibial angle) and ratio of joint space (medial/lateral joint space). Functional Outcome was assessed with American Knee Society Score (KSS) and Knee pain was assessed with Visual analogue scale.Results: At final followup the mean Femoro-Tibial angle and joint space ratio were 180.4 and 0.54 respectively. The limb alignment is corrected in few cases and joint space ratio is increased postoperatively. Mean Knee Society Score at final follow up was 75.13 which was higher than the mean preoperative score 52.5.Mean Vas score is reduced significantly up to 4(preoperative mean Vas score was 8).Conclusion: The present study demonstrates the proximal fibular osteotomy effectively relieves the pain and improves the joint function in the patients with medial compartment osteoarthritis of knee by shifting the mechanical axis. Conversion to total knee replacement or unicompartmental arthroplasty is also less complicated.