Ultrasound Arthroscopy of Human Knee Cartilage and Subchondral Bone in Vivo

Arthroscopic ultrasound imaging enables quantitative evaluation of articular cartilage. However, the potential of this technique for evaluation of subchondral bone has not been investigated in vivo. In this study, we address this issue in clinical arthroscopy of the human knee (n = 11) by determining quantitative ultrasound (9 MHz) reflection and backscattering parameters for cartilage and subchondral bone. Furthermore, in each knee, seven anatomical sites were graded using the International Cartilage Repair Society (ICRS) system based on (i) conventional arthroscopy and (ii) ultrasound images acquired in arthroscopy with a miniature transducer. Ultrasound enabled visualization of articular cartilage and subchondral bone. ICRS grades based on ultrasound images were higher (p < 0.05) than those based on conventional arthroscopy. The higher ultrasound-based ICRS grades were expected as ultrasound reveals additional information on, for example, the relative depth of the lesion. In line with previous literature, ultrasound reflection and scattering in cartilage varied significantly (p < 0.05) along the ICRS scale. However, no significant correlation between ultrasound parameters and structure or density of subchondral bone could be demonstrated. To conclude, arthroscopic ultrasound imaging had a significant effect on clinical grading of cartilage, and it was found to provide quantitative information on cartilage. The lack of correlation between the ultrasound parameters and bone properties may be related to lesser bone change or excessive attenuation in overlying cartilage and insufficient power of the applied miniature transducer.     

Relation of EEG spectrum progression to loss of responsiveness during induction of anesthesia with propofol.

OBJECTIVE: Our purpose is to find out whether the Loss of obeying a Verbal Command (LVC) and the preceding progression of the EEG frequency patterns are mutually related during an anesthetic induction. METHODS: EEG was analyzed from sixteen patients, anesthetized with a fixed rate infusion of propofol (30 mg/kg/h). An artifact-purified EEG from electrode Fz referenced to the average of mastoid signals was filtered to consecutive 4 Hz frequency passbands with a filter bank. Signal envelope time-series were computed for all the passbands and studied as a function of the elapsed induction time t and as a function of the relative time r, which is t divided by the time of the LVC. RESULTS: A frequency band specific biphasic activity pattern progressed from high towards low frequencies systematically and uniformly in the population studied when presented on the relative time scale r, irrespective of individual responses to the dosage. CONCLUSIONS: The grouping of the individual progression patterns on the r scale indicates a strong relation between the EEG spectral behavior and the LVC. SIGNIFICANCE: EEG may provide phenomenological grounds for a continuous control variable of a sedative drug effect, even in between the discrete clinical end-points.     

Estimation of the Effect of Body Weight on the Development of Osteoarthritis Based on Cumulative Stresses in Cartilage: Data from the Osteoarthritis Initiative

Evaluation of the subject-specific biomechanical effects of obesity on the progression of OA is challenging. The aim of this study was to create 3D MRI-based finite element models of the knee joints of seven obese subjects, who had developed OA at 4-year follow-up, and of seven normal weight subjects, who had not developed OA at 4-year follow-up, to test the sensitivity of cumulative maximum principal stresses in cartilage in quantitative risk evaluation of the initiation and progression of knee OA. Volumes of elements with cumulative stresses over 5 MPa in tibial cartilage were significantly (p < 0.05) larger in obese subjects as compared to normal weight subjects. Locations of high peak cumulative stresses at the baseline in most of the obese subjects showed a good agreement with the locations of the cartilage loss and MRI scoring at follow-up. Simulated weight loss (to body mass index 24 kg/m²) in obese subjects led to significant reduction of the highest cumulative stresses in tibial and femoral cartilages. The modeling results suggest that an analysis of cumulative stresses could be used to evaluate subject-specific effects of obesity and weight loss on cartilage responses and potential risks for the progression of knee OA.     

Effects of High‐Impact Training on Bone and Articular Cartilage: 12‐Month Randomized Controlled Quantitative MRI Study

Osteoarthritis and osteoporosis often coexist in postmenopausal women. The simultaneous effect of bone‐favorable high‐impact training on these diseases is not well understood and is a topic of controversy. We evaluated the effects of high‐impact exercise on bone mineral content (BMC) and the estimated biochemical composition of knee cartilage in postmenopausal women with mild knee osteoarthritis. Eighty women aged 50 to 66 years with mild knee osteoarthritis were randomly assigned to undergo supervised progressive exercise three times a week for 12 months (n = 40) or to a nonintervention control group (n = 40). BMC of the femoral neck, trochanter, and lumbar spine was measured by dual‐energy X‐ray absorptiometry (DXA). The biochemical composition of cartilage was estimated using delayed gadolinium‐enhanced magnetic resonance imaging (MRI) cartilage (dGEMRIC), sensitive to cartilage glycosaminoglycan content, and transverse relaxation time (T2) mapping that is sensitive to the properties of the collagen network. In addition, we evaluated clinically important symptoms and physical performance–related risk factors of falling: cardiorespiratory fitness, dynamic balance, maximal isometric knee extension and flexion forces, and leg power. Thirty‐six trainees and 40 controls completed the study. The mean gain in femoral neck BMC in the exercise group was 0.6% (95% CI, –0.2% to 1.4%) and the mean loss in the control group was –1.2% (95% CI, –2.1% to –0.4%). The change in baseline, body mass, and adjusted body mass change in BMC between the groups was significant (p = 0.005), whereas no changes occurred in the biochemical composition of the cartilage, as investigated by MRI. Balance, muscle force, and cardiorespiratory fitness improved significantly more (3% to 11%) in the exercise group than in the control group. Progressively implemented high‐impact training, which increased bone mass, did not affect the biochemical composition of cartilage and may be feasible in the prevention of osteoporosis and physical performance–related risk factors of falling in postmenopausal women. © 2014 American Society for Bone and Mineral Research.     

Age-related trends in vertebral dimensions

Several studies have demonstrated age-related changes in vertebral dimensions. Vertebral size has been reported to increase among elderly adults, with periosteal apposition resulting in increased cross-sectional area (CSA) of the vertebral corpus combined with reduction in bone mineral density. These changes in CSA are observed to be sex-specific, as the pronounced increase of vertebral CSA is found only in elderly males. However, the reduction in bone mineral density in old age is apparent within both sexes. It is thus hypothesized that higher fracture risk in elderly women is a result of their incapacity to increase vertebral size and thus adapt to bone mineral reduction. In this study, our aim was to explore whether the onset of these changes could be ascribed to specific age intervals and whether the proposed differences between the sexes are as great as previously suggested. To conduct this study we utilized two large early 20th century skeletal collections known as Terry and Bass (n = 181). We also utilized data from two lumbar spine magnetic resonance imaging samples as a modern-day reference (n = 497). Age, sex and ethnicity of all individuals were known. Vertebral CSA was determined by measuring three width and length dimensions from the corpus of the fourth lumbar vertebra (L4). Our results indicate only a moderate association between age and vertebral CSA. This association was observed to be relatively similar in both sexes, and we thus conclude that there is no clear sex-specific compensatory mechanism for age-related bone loss in vertebral size.     

Measuring the productive efficiency and clinical quality of institutional long-term care for the elderly

The authors consider the association between productive efficiency and clinical quality in institutional long-term care for the elderly. Cross-sectional data were collected from 122 wards in health-centre hospitals and residential homes in Finland in 2001. Productive efficiency was measured in terms of technical efficiency, which was defined as the unit's distance from the (best practice) production frontier. The analysis employed stochastic production frontier estimation, where technical inefficiency in the production function was specified to be a function of ward characteristics and clinical quality of care. Several quality indicators based on the Resident Assessment Instrument, such as prevalence of pressure ulcers and depression with no treatment, were used in the analysis. The results did not reveal systematic association between technical efficiency and clinical quality of care. However, the prevalence of pressure ulcers, indicating poor quality of care was associated with technical efficiency, a fact which highlights the importance of including quality measures in the assessment of efficiency in long-term care.     

Ranges of motion after reverse shoulder arthroplasty improve significantly the first year after surgery in patients with rheumatoid arthritis

Objectives

To evaluate the trajectory of the change in range of motion after reverse shoulder joint replacement during 3-year follow-up among patients with rheumatoid arthritis.

Methods

Retrospective cohort longitudinal study of 76 shoulder replacements performed in a university clinic. The range of shoulder motion was assessed by a physiotherapist using a manual goniometer with 5-degree precision before the surgery and 1, 3, 6, 12, and 36 months postoperatively.

Results

The shapes of the regression curves suggest that the improvement or decline observed in joint motion was happening mostly during the first year after surgery. After 1 year, the trajectories become flat and they remained unchanged until the end of follow-up.

Conclusions

After shoulder joint replacement, the range of shoulder motion showed substantial changes during the first year only. This should be taken into account when scheduling control visits, planning rehabilitation, and predicting the use of community services after the surgery.

     

The nationwide Finnish anticoagulation in atrial fibrillation (FinACAF): study rationale,design, and patient characteristics

European Journal of Epidemiology - Atrial fibrillation (AF) is a major cause of ischemic stroke and the number of AF patients is increasing. Thus, up-to-date multifaceted data about the...