Osteoarthritis development related to cartilage quality-the prognostic value of dGEMRIC after anterior cruciate ligament injury.

OBJECTIVE: Rupture of the anterior cruciate ligament (ACL) increases the risk of developing osteoarthritis (OA). Delayed Gadolinium enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) investigates cartilage integrity through T1-analysis after intravenous contrast injection. A high dGEMRIC index represents good cartilage quality. The main purpose of this prospective cohort study was to investigate the prognostic value of the dGEMRIC index regarding future knee OA. METHOD: 31 patients with ACL injury (mean age 27 ± 6.7 (±SD) years, 19 males) were examined after 2 years with 1.5T dGEMRIC of femoral cartilage. Re-examination 14 years post-injury included weight-bearing knee radiographs, Lysholm and Knee Osteoarthritis Outcome Score (KOOS). RESULTS: At the 14-year follow up radiographic OA (ROA) was present in 68% and OA symptoms (SOA) in 42% of the injured knees. The dGEMRIC index of the medial compartment was lower in knees that developed medial ROA, 325 ± 68 (ms±SD) vs 376 ± 47 (51 (7-94)) (difference of means (95% confidence interval (CI))), in patients that developed symptomatic OA (SOA), 327 ± 61 vs 399 ± 42 (52 (11-93)), and poor knee function 337 ± 54 vs 381 ± 52 (48 (7-89)) compared to those that did not develop ROA, SOA or poor function. The dGEMRIC index correlated negatively with the OARSI osteophyte score in medial (r = -0.44, P = 0.01) and lateral (r = -0.38, P = 0.03) compartments. CONCLUSION: The associations between a low dGEMRIC index and future ROA, as well as SOA, are in agreement with previous studies and indicate that dGEMRIC has a prognostic value for future knee OA.

[Fixation techniques for slipped capital femoral epiphysis : Principles, surgical techniques, and complications]. / Fixationstechniken bei der Epiphyseolysis capitis femoris : Prinzipien, operative Techniken und Komplikationen.

The purpose of this review is to present the pros and cons as well as the surgical techniques of conventional implants used for fixation of slipped capital femoral epiphysis (SCFE). Worth mentioning are K­wires, Hansson pins, transfixing screws, and gliding screws. We searched PubMed for "ECF" and "SCFE" in combination with "in situ fixation," "pin," "wire," "screw," and "nail." We considered Johansson nail, Knowles pin, and Nyström nail to be obsolete and of historical interest only. We noticed a trend from absolute stability towards some form of dynamic fixation over time, likely related to considerations of growth disturbance of the proximal femur and also the inherent potential for remodeling with time.

Persisting CAM deformity is associated with early cartilage degeneration after Slipped Capital Femoral Epiphysis: 11-year follow-up including dGEMRIC.

OBJECTIVE: Slipped capital femoral epiphysis (SCFE) in adolescence is associated with increased risk of future osteoarthritis (OA). The purpose of this study was to study clinical and radiographic risk factors for early cartilage degeneration after SCFE. DESIGN: 22 patients (44 hips) (mean age 24 years, range 18-27) treated with in situ fixation (The Hansson hook-pin) for stable SCFE on average 11 years previously were investigated. Cartilage status was assessed with delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC). The alpha angle, reflecting femoroacetabular impingement (FAI), and the original slip angle were measured. Clinical outcome was assessed with the Copenhagen hip and groin outcome score (HAGOS) and clinical examination. RESULTS: The dGEMRIC index was lower in SCFE hips than unaffected hips 456 ms (CI 419-493) vs 521 ms (CI 476-567) (P = 0.03). The difference was larger (mean 21 ms) in anterior than posterior regions of the hip (P = 0.038). The alpha angle was higher in SCFE hips, 61.5° (CI 53.9-69.1) vs 45.6° (CI 43.6-47.6), (P < 0.001). The alpha angle, but not the original slip angle, correlated negatively with the dGEMRIC index (R = -0.40, P = 0.046). There was a positive correlation between HAGOS and the dGEMRIC-index (R = 0.41, P = 0.012). CONCLUSIONS: Early cartilage degeneration after SCFE seems related to persisting FAI in adulthood, rather than the initial slip severity. The correlation between dGEMRIC and HAGOS indicates a clinical relevance of the MRI findings. Our results suggest that FAI after SCFE should be evaluated already after physeal closure in order to predict and possibly prevent future OA development.

Residual hip dysplasia at 1 year after treatment for neonatal hip instability is not related to degenerative joint disease in young adulthood: a 21-year follow-up study including dGEMRIC.

OBJECTIVE: Developmental dysplasia of the hip (DDH) is associated with an increased risk of early hip osteoarthritis (OA). We aimed to examine the outcome at the completion of growth in a cohort of children who had residual acetabular dysplasia at age 1 year following early treatment for neonatal instability of the hip (NIH). DESIGN: We examined 21 of 30 subjects who had been treated with the von Rosen splint neonatally for NIH and had residual acetabular dysplasia at age 1 year. Mean follow-up time was 21 years (range 17-24). Signs of OA and acetabular dysplasia were assessed by radiography. Cartilage quality was assessed by delayed Gadolinium Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC), a tool for molecular imaging of cartilage quality, at 1.5 T. Patient reported outcome (PRO) was assessed by the 12-item WOMAC score. RESULTS: No study participant had radiographic OA (defined as Kellgren-Lawrence grade ≥2) or minimum joint space width (JSW) ≤2 mm. The mean dGEMRIC index was 630 ms (95% CI: 600-666, range: 516-825) suggesting good cartilage quality. The mean 12-item WOMAC score was 1.2. Two of three radiographic measurements of DDH correlated positively to the dGEMRIC index. CONCLUSIONS: Children treated neonatally for NIH have good hip function and no signs of cartilage degeneration at 21-year follow-up, despite residual dysplasia at age 1 year. Unexpectedly, radiographic signs of dysplasia were associated with better cartilage quality, as assessed with dGEMRIC. This may indicate cartilage adaptation to increased mechanical stress in mild hip dysplasia.

Regional dGEMRIC analysis in patients at risk of osteoarthritis provides additional information about activity related changes in cartilage structure.

BACKGROUND: Previously, a positive effect of exercise on cartilage structure was indicated with delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC). However, in that study only one full-thickness region of interest (ROI) in the medial femoral condyle was analyzed. PURPOSE: To improve the knowledge about exercise effects on cartilage structure by re-analyzing previous images with regional dGEMRIC analysis. MATERIAL AND METHODS: Thirty patients (age range, 38-50 years) with a previous medial meniscus resection were divided into three groups according to self-reported change in physical activity (PA) level in a 4-month exercise intervention study: Group I (n = 11), increased PA level; Group II (n = 13), no change in PA level; and Group III (n = 6), reduced PA level. dGEMRIC index was analyzed at inclusion and after 4 months. Anterior (less load) and posterior (more load) ROIs of medial and lateral femoral condyles were analyzed, as well as superficial and deep cartilage regions. RESULTS: Group I increased the dGEMRIC index in the posterior cartilage (P = 0.004). The increase was larger in the lateral (P = 0.005) than the medial compartment in both superficial and deep cartilage regions. The dGEMRIC index did not change in Group II. In Group III, the dGEMRIC index decreased in the medial posterior cartilage (P = 0.03). CONCLUSION: In patients with a previous medial meniscectomy, the beneficial effect of exercise varies between different locations within the joint, the largest improvement being observed in lateral posterior cartilage, i.e. the load-bearing cartilage in the compartment without a meniscus lesion. The effects of exercise do not seem to vary with cartilage depth.

Long-term effect of removal of knee joint loading on cartilage quality evaluated by delayed gadolinium-enhanced magnetic resonance imaging of cartilage.

OBJECTIVE: Ankle fracture patients were used as a model to study the long-term effect of the removal of joint loading on knee cartilage quality in human subjects. DESIGN: The knees of 10 patients with ipsilateral ankle fractures were investigated using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) at the time of ankle injury. After 6 weeks' prescribed unloading of the affected leg, but no restrictions regarding knee movement, the cast was removed from the ankle and the patient underwent a second dGEMRIC examination. Physiotherapy was then initiated. A third dGEMRIC examination was performed 4 months after remobilization, and a final examination 1 year after the injury. RESULTS: Baseline T1Gd values for the 10 patients were within a narrow range. No significant change in mean T1Gd was observed after 6 weeks' prescribed unloading, but the T1Gd range had increased significantly. Four months after remobilization, the mean T1Gd was significantly lower than in the previous examinations, and the range remained significantly broader than at baseline. At the 1-year follow-up, the mean T1Gd was almost identical to the value after remobilization, and the T1Gd range still showed a significant increase compared to the baseline investigation. CONCLUSIONS: Removal of knee cartilage loading for 6 weeks resulted in a measurable effect on the cartilage matrix, as evidenced by a broader T1Gd range. A decrease in mean T1Gd was observed 4 months after remobilization. These differences persisted a year after injury compared to baseline.

Knee cartilage assessment with MRI (dGEMRIC) and subjective knee function in ACL injured copers: a cohort study with a 20 year follow-up.

OBJECTIVE: To assess knee cartilage quality and subjective knee function, 20 years after injury in anterior cruciate ligament (ACL) injured copers. METHOD: We examined 32 knees using delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC), 20 years after a complete ACL tear. Only subjects who had coped with the ACL injury without ACL reconstruction (ACLR), and who presented without radiographic signs of osteoarthritis (OA) at an earlier 16-year follow-up, were included in this study. The quality of the central weight-bearing parts of the medial and lateral femoral cartilage was estimated with dGEMRIC (T1Gd). These results were compared with corresponding results in 24 healthy individuals, and with the subjects' self-reported subjective knee function using the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. RESULTS: The values of T1Gd in the medial and lateral femoral cartilage of the study group (mean (95% CI)), were 404 (385-423) and 427 (399-455) ms, not statistically different from those of the healthy reference group (P = 0.065 and 0.31). The subjective knee function 20 years after the injury, according to the five domains of the KOOS score, was good, with a mean score of 90 ± 11. Values of T1Gd for the medial femoral cartilage were correlated with the KOOS subgroup QOL (P = 0.021, Pearson correlation). CONCLUSIONS: Subjects who have managed to cope with their ACL injury for 20 years with sustained good subjective knee function also seem to have knee cartilage of good quality, with T1Gd values not very different from a healthy reference group.

Imaging following acute knee trauma.

Joint injury has been recognized as a potent risk factor for the onset of osteoarthritis. The vast majority of studies using imaging technology for longitudinal assessment of patients following joint injury have focused on the injured knee joint, specifically in patients with anterior cruciate ligament injury and meniscus tears where a high risk for rapid onset of post-traumatic osteoarthritis is well known. Although there are many imaging modalities under constant development, magnetic resonance (MR) imaging is the most important instrument for longitudinal monitoring after joint injury. MR imaging is sensitive for detecting early cartilage degeneration and can evaluate other joint structures including the menisci, bone marrow, tendons, and ligaments which can be sources of pain following acute injury. In this review, focusing on imaging following acute knee trauma, several studies were identified with promising short-term results of osseous and soft tissue changes after joint injury. However, studies connecting these promising short-term results to the development of osteoarthritis were limited which is likely due to the long follow-up periods needed to document the radiographic and clinical onset of the disease. Thus, it is recommended that additional high quality longitudinal studies with extended follow-up periods be performed to further investigate the long-term consequences of the early osseous and soft tissue changes identified on MR imaging after acute knee trauma.

Association between delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and joint space narrowing and osteophytes: a cohort study in patients with partial meniscectomy with 11 years of follow-up.

OBJECTIVE: To examine the association between the relaxation time (T1Gd) of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and grade of tibiofemoral joint space narrowing (JSN) and osteophytosis 11 years later, in a cohort of meniscectomized patients. DESIGN: Patients (n = 45) aged 35-50 who had undergone an arthroscopic partial medial meniscectomy 1-6 years earlier, due to degenerative meniscal tear, were examined using dGEMRIC. These patients had no cartilage changes defined as deep clefts or visible bone at the time of arthroscopy. Eleven years later (12-16 years after surgery) 34 of these subjects (76%) were evaluated by weight-bearing knee radiography, and tibiofemoral joint changes were graded according to the Osteoarthritis Research Society International Atlas. RESULTS: Lower T1Gd in the medial compartment was associated with higher grade of medial JSN (grade 0, 351 ms; grade 1, 386 ms; grade 2, 342 ms; grade 3, 259 ms [P for trend < 0.001]) and more osteophytosis (score 0, 371 ms; score 1, 389 ms; score 2, 354 ms; score 3, 289 ms; score 4, 265 ms; score 5, 275 ms [P for trend = 0.001]). Lower T1Gd in the lateral compartment was associated with higher grade of lateral JSN (grade 0, 436 ms; grade 1, 346 ms [P for trend = 0.026]). CONCLUSION: The current study suggests that lower T1Gd measured with dGEMRIC of medial and lateral femoral cartilage is associated with higher grade of JSN 11 years later, and medially, also with more osteophytosis.

Reproducibility of 3D delayed gadolinium enhanced MRI of cartilage (dGEMRIC) of the knee at 3.0 T in patients with early stage osteoarthritis.

OBJECTIVES: To assess the reproducibility of 3D delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) at 3 T in early stage knee osteoarthritis (OA) patients. METHODS: In 20 patients, 3D dGEMRIC at 3 T was acquired twice within 7 days. To correct for patient motion during acquisition, all images were rigidly registered in 3D. Eight anatomical cartilage ROIs were analysed on both images of each patient. Capability of dGEMRIC to yield T1 maps that reproducibly distinguish spatial differences in cartilage quality was assessed in two ROIs within a single slice in each patient. Reproducibility was assessed using ICCs and Bland-Altman plots. RESULTS: ICCs ranged from 0.87 to 0.95, indicating good reproducibility. T1 maps revealed reproducible spatial differences in cartilage quality (ICC 0.79). Based on the Bland-Altman plots, we defined a threshold of 95 ms to determine if a change in dGEMRIC outcome in longitudinal research was statistically significant. CONCLUSIONS: 3D knee dGEMRIC at 3 T combined with 3D image registration is a highly reproducible measure of cartilage quality in early stage OA. Therefore, dGEMRIC may be a valuable tool in the non-invasive evaluation of cartilage quality changes in longitudinal research in patients with early stage OA and focal cartilage defects.

Longitudinal assessment of femoral knee cartilage quality using contrast enhanced MRI (dGEMRIC) in patients with anterior cruciate ligament injury--comparison with asymptomatic volunteers.

OBJECTIVE: In this observational longitudinal study we estimate knee joint cartilage glycosaminoglycan (GAG) content, in patients with an acute anterior cruciate ligament (ACL) injury, with or without a concomitant meniscus injury. METHODS: 29 knees (19 men/10 women) were prospectively examined by repeat delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), approximately 3 weeks and 2.3±1.3 (range 4.5) years after the injury. We estimated the GAG content (T1Gd) in the central weight-bearing parts of the medial and lateral femoral cartilage and compared results with a reference cohort (n=24) with normal knees and no history of injury examined by dGEMRIC at one occasion previously. RESULTS: The healthy reference group had longer T1Gd values compared with the ACL-injured patients at follow-up both medially: 428±38 vs 363±61ms (P<0.0001) and laterally: 445±41 vs 396±48ms (P=0.0002). At follow-up T1Gd was lower in meniscectomized patients compared to those without a meniscectomy, both medially (-84ms, P=0.002) and laterally (-38ms, P=0.05). In the injured group, the medial femoral cartilage showed similar T1Gd at the two dGEMRIC investigations: 357±50 vs 363±61ms (P=0.57), whereas the lateral femoral cartilage T1Gd increased: 374±48 vs 396±48ms (P=0.04). CONCLUSIONS: The general decrease in cartilage T1Gd in ACL-injured patients compared with references provide evidence for structural matrix GAG changes that seem more pronounced if a concomitant meniscal injury is present. The fact that post-traumatic OA commonly develops in ACL-injured patients, in particularly those with meniscectomy, suggests that shorter T1Gd may be an early biomarker for OA.

Relationship between cartilage glycosaminoglycan content (assessed with dGEMRIC) and OA risk factors in meniscectomized patients.

OBJECTIVE: To study the relationship between cartilage integrity, assessed with [delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC)] and epidemiologic risk factors for knee osteoarthritis (OA) in meniscectomized patients. METHODS: Body mass index (BMI) was calculated in 45 patients (16 women), mean age 46, who underwent an arthroscopic medial meniscectomy 1-6 years earlier. The cartilage glycosaminoglycan (GAG) content was estimated by dGEMRIC Index and tests of isokinetic muscle strength and functional performance (one-leg hop test) were conducted. RESULTS: BMI ranged from 20.0 to 34.3 (mean: 26.5). The dGEMRIC Index was 14.4% lower in the medial index compartment (374+/-61 ms, mean+/-SD) than in the lateral reference compartment (437+/-59 ms, mean+/-SD) (P<0.001). The dGEMRIC Index of the medial diseased compartment correlated positively with both knee flexor (r=0.50, P=0.001) and knee extensor strength (r=0.47, P=0.001) relative to body weight and with the one-leg hop test (r=0.42, P=0.004). Furthermore, a negative correlation was found between the dGEMRIC Index of the medial compartment and BMI (r=-0.35, P=0.019). No significant correlations were found in the lateral reference compartment. CONCLUSION: The lower dGEMRIC Index of the medial compartment suggests decreased cartilage GAG content after medial meniscectomy, indicating an early stage OA. Furthermore, results suggest that overweight is a factor that deteriorates cartilage, whereas strong and co-ordinated thigh muscles may have a protective effect on the cartilage integrity.

Decreasing incidence of fractures in children: an epidemiological analysis of 1,673 fractures in Malmö, Sweden, 1993-1994.

The incidence of fractures in children in the city of Malmö, Sweden, almost doubled between 1950 and 1979. To see whether a further increase had occurred, we carried out an epidemiological analysis of fractures among children 0-16 years in Malmö 1993-1994. During the study period, 1,673 fractures occurred in 1,610 children. The commonest fracture location was the distal forearm (26%), followed by the phalanges of the hand (16%) and the clavicle (9%). The annual fracture incidence was 235/10(4) in boys, 149/10(4) in girls and 193/10(4) for both genders. This means a decrease in the annual fracture incidence by 9% since 1975-1979. The decrease was not associated with any specific type of fracture or etiological factor. Fractures of the distal forearm among girls were an exception to the general decline, having increased by one third since 1975-1979, which might be explained by the fact that today girls participate to a greater extent in the same sports as boys.

Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC): intra- and interobserver variability in standardized drawing of regions of interest.

PURPOSE: To establish the reproducibility of a standardized region of interest (ROI) drawing procedure in delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC). MATERIAL AND METHODS: A large ROI in lateral and medial femoral weight-bearing cartilage was drawn in images of 12 healthy male volunteers by 6 investigators with different skills in MRI. The procedure was done twice, with a 1-week interval. Calculated T1-values were evaluated for intra- and interobserver variability. RESULTS: The mean interobserver variability for both compartments ranged between 1.3% and 2.3% for the 6 different investigators without correlation to their experience in MRI. Post-contrast intra-observer variability was low in both the lateral and the medial femoral cartilage, 2.6% and 1.5%, respectively. The larger variability in lateral than in medial cartilage was related to slightly longer and thinner ROIs. CONCLUSION: Intra-observer variability and interobserver variability are both low when a large standardized ROI is used in dGEMRIC. The experience of the investigator does not affect the variability, which further supports a clinical applicability of the method.

Gd-DTPA2)-enhanced MRI of femoral knee cartilage: a dose-response study in healthy volunteers.

The negatively charged contrast agent Gd-DTPA2- distributes inversely to the cartilage fixed charged density. This enables structural cartilage examinations by contrast-enhanced MRI. In line with the development of a clinically applicable protocol for such examinations, this study describes the temporal pattern of Gd-DTPA2- distribution in femoral knee cartilage at three different doses in healthy volunteers. Nineteen volunteers (ages 21-28 years) were examined with a 1.5T MRI system. Quantitative relaxation rate measurements were made in weight-bearing central parts of femoral cartilage using sets of five turbo inversion recovery images with different inversion times. The cartilage was analyzed before and four times (1-4 h) after an intravenous injection of Gd-DTPA2- at single, double, and triple doses: 0.1, 0.2, and 0.3 mmol/kg body weight, respectively. The increase in R1 postcontrast was linearly dose-related at all times. The highest R1 values were registered at 2 and 3 h postcontrast, suggesting 2 h to be optimal in the clinical situation. The triple dose indicated a subtle compartmental difference in men, with higher contrast distribution medially than laterally. Results suggest that the triple dose is needed to detect minor cartilage matrix differences.