Detection of Interstitial Lung Disease in Rheumatoid Arthritis by Thoracic Ultrasound. A Diagnostic Test Accuracy study.

OBJECTIVE: The Objective was to determine the diagnostic accuracy of thoracic ultrasound (TUS) for detecting (ILD) in rheumatoid arthritis (RA) with respiratory symptoms. METHODS: Individuals with RA visiting Rheumatological outpatient clinics in the Region of Southern Denmark were systematically screened for dyspnoea, cough, recurrent pneumonia, prior severe pneumonia or a chest X-ray indicating interstitial abnormalities. Eighty participants with a positive screening were consecutively included. Individuals were not eligible if they had a chest high-resolution CT (HRCT) <12 months or were already diagnosed with ILD. A blinded TUS expert evaluated TUS, and TUS was registered as positive for ILD if ≥10 B-lines or bilateral thickened and fragmented pleura were present. The primary outcomes were TUS's sensitivity, specificity, and positive predictive value (PPV) and negative predictive value (NPV). An ILD-specialised thoracic radiologist assessed HRCT, followed by a multi-disciplinary team discussion, which was the reference standard. The accepted window of HRCT was <30 days after TUS was performed. RESULTS: 77 participants received HRCT <30 days after TUS, and 23 (30%) were diagnosed with ILD. TUS had a sensitivity of 82.6% (95% CI: 61.2% to 95.0%) and a specificity of 51.9% (95% CI: 37.8% to 65.7%), corresponding to a PPV of 42.2% (95%CI 27.7% to 57.8%) and an NPV of 87.5% (95% CI 71.0% to 96.5%). CONCLUSION: To our knowledge, this prospective study is the first to use respiratory symptoms in RA as inclusion criteria. Systematic screening for respiratory symptoms combined with TUS can reduce the diagnostic delay of ILD in RA.

Clinical and radiological signs of bone healing in conservatively treated fractures in adults.

Traumatic fractures are often treated conservatively. Bone healing is a complex process and the complexities of a fracture, bone quality, treatment, and patient factors are all crucial. Routine X-rays and clinical follow-ups are a significant cost to society as well as exposing the patient to increased radiation and should only be performed if there is a risk of complications that may impact the treatment. It is difficult to assess on X-rays alone, whether there is sufficient bone healing and X-rays are therefore always recommended in conjunction with clinical examination.

Reliability and correlation of weight-bearing cone beam CT and Foot Posture Index (FPI) for measurements of foot posture: a test-retest study.

OBJECTIVE: To assess test-retest reliability and correlation of weight-bearing (WB) and non-weight-bearing (NWB) cone beam CT (CBCT) foot measurements and Foot Posture Index (FPI) MATERIALS AND METHODS: Twenty healthy participants (age 43.11±11.36, 15 males, 5 females) were CBCT-scanned in February 2019 on two separate days on one foot in both WB and NWB positions. Three radiology observers measured the navicular bone position. Plantar (ΔNAVplantar) and medial navicular displacements (ΔNAVmedial) were calculated as a measure of foot posture changes under loading. FPI was assessed by two rheumatologists on the same two days. FPI is a clinical measurement of foot posture with 3 rearfoot and 3 midfoot/forefoot scores. Test-retest reproducibility was determined for all measurements. CBCT was correlated to FPI total and subscores. RESULTS: Intra- and interobserver reliabilities for navicular position and FPI were excellent (intraclass correlation coefficient (ICC) .875-.997). In particular, intraobserver (ICC .0.967-1.000) and interobserver reliabilities (ICC .946-.997) were found for CBCT navicular height and medial position. Interobserver reliability of ΔNAVplantar was excellent (ICC .926 (.812; .971); MDC 2.22), whereas the ΔNAVmedial was fair-good (ICC .452 (.385; .783); MDC 2.42 mm). Using all observers' measurements, we could calculate mean ΔNAVplantar (4.25±2.08 mm) and ΔNAVmedial (1.55±0.83 mm). We demonstrated a small day-day difference in ΔNAVplantar (0.64 ±1.13mm; p<.05), but not for ΔNAVmedial (0.04 ±1.13mm; p=n.s.). Correlation of WBCT (WB navicular height - ΔNAVmedial) with total clinical FPI scores and FPI subscores, respectively, showed high correlation (ρ: -.706; ρ: -.721). CONCLUSION: CBCT and FPI are reliable measurements of foot posture, with a high correlation between the two measurements.

The Effect of Endoscopic Partial Plantar Fasciotomy on Morphologic and Functional Properties of the Foot.

BACKGROUND: The lifetime risk of plantar fasciitis is 10%, and operative treatment in the form of endoscopic partial plantar fascia release are often performed in cases refractory for nonsurgical treatment. The effect of the operation on the biomechanical properties of the foot has only been sparsely studied. METHODS: This is a prospective, observational study of 25 patients with plantar fasciitis, for a minimum of 3 months, verified by ultrasonographic scanning, who had endoscopic partial fasciotomy. A bony spur was resected if present. At the calcaneal insertion, the medial half of the central band of the plantar fascia was excised in full thickness. The biomechanical properties of the foot were evaluated before surgery and 12 months postoperatively. RESULTS: Foot length increased 0.17 cm (P = .03), the width of the central zone 0.35 cm (P = .019), the modified arch index 0.05 (P = .032), and the Foot Posture Index 1.0 (P = .0014). There were no significant changes in rearfoot eversion angle, ankle dorsiflexion and jump distance, or in magnetic resonance imaging-measured 3D navicular position from pre- to postoperation, with or without loading, and no changes in ultrasonographically measured heel pad thickness. A tantalum bead (0.7-mm-diameter) was inserted during operation into the most proximal part of the released medial plantar fascia. Radiographs obtained few days postoperatively and 1 year later revealed no changes in the tantalum-calcaneus distance in supine position, but an increase from 48.3 to 50.7 mm (P = .045) in one-leg standing, suggesting a higher flexibility of the remaining fascia. Patients with a body mass index above and below 27.0 demonstrated no significant differences in any of the assessments at 12 months. CONCLUSION: There were minimal changes in the measured foot morphologic and functional properties at 1-year follow-up, after endoscopic partial plantar fascia release. LEVEL OF EVIDENCE: Level II, prospective cohort study.

Comparison between conventional MRI and weight-bearing positional MRI reveals important differences in radiological measurements of the patellofemoral joint.

OBJECTIVE: To compare radiological measurements of the patellofemoral joint (PFJ) morphology and measurement reproducibility across the following scanning modalities: (a) 3 T supine MRI, (b) 0.25 T supine MRI and (c) standing 0.25 T MRI. METHODS: Forty patients referred to MRI of the knee were scanned by high field 3 T MRI in supine position and low field 0.25 T positional (pMRI) in supine and standing positions. Radiological measurements for assessment of femoral trochlear morphology, patellar tracking, patellar height and knee flexion angle were compared across scanning situations by one-way repeated-measures ANOVA. Measurement reliability and agreement were assessed by calculation of ICC, SEM and MDC. RESULTS: Patellar tracking differed across scanning situations, particularly between 3.0 T supine and 0.25 T standing position. Mean differences are the following: patella bisect offset (PBO): 9.6%, p ≤ 0.001; patellar tilt angle (PTA): 3.1°, p ≤ 0.001; tibial tuberosity-trochlear groove distance (TT-TG): 2.7 mm, p ≤ 0.001). Measurements revealed slight knee joint flexion in supine and slight hyperextension in the standing position (MD: 9.3°, P ≤ 0.001), likely related to the observed differences in patellar tracking. Reproducibility was comparable across MRI field strengths. In general, PBO, PTA and TT-TG were the most robust measurements in terms of reproducibility and agreement across scanning situations (ICC range: 0.85-0.94). CONCLUSION: Significant differences in important patellofemoral morphology measurements were observed between supine and standing MRI scanning positions. These were unlikely due to physiological factors such as changes in joint loading but rather induced by slight differences in knee flexion angle. This emphasises the need to standardise knee positioning during scanning, particularly for weight-bearing positional MRI before clinical use.

Weight-bearing cone-beam CT: the need for standardised acquisition protocols and measurements to fulfill high expectations-a review of the literature.

Weight bearing CT (WBCT) of the lower extremity is gaining momentum in evaluation of the foot/ankle and knee. A growing number of international studies use WBCT, which is promising for improving our understanding of anatomy and biomechanics during natural loading of the lower extremity. However, we believe there is risk of excessive enthusiasm for WBCT leading to premature application of the technique, before sufficiently robust protocols are in place e.g. standardised limb positioning and imaging planes, choice of anatomical landmarks and image slices used for individual measurements. Lack of standardisation could limit benefits from introducing WBCT in research and clinical practice because useful imaging information could become obscured. Measurements of bones and joints on WBCT are influenced by joint positioning and magnitude of loading, factors that need to be considered within a 3-D coordinate system. A proportion of WBCT studies examine inter- and intraobserver reproducibility for different radiological measurements in the knee or foot with reproducibility generally reported to be high. However, investigations of test-retest reproducibility are still lacking. Thus, the current ability to evaluate, e.g. the effects of surgery or structural disease progression, is questionable. This paper presents an overview of the relevant literature on WBCT in the lower extremity with an emphasis on factors that may affect measurement reproducibility in the foot/ankle and knee. We discuss the caveats of performing WBCT without consensus on imaging procedures and measurements.

Using thoracic ultrasound to detect interstitial lung disease in patients with rheumatoid arthritis: a protocol for the diagnostic test accuracy AURORA study.

INTRODUCTION: Pulmonary diseases are significant contributors to morbidity and mortality in patients with rheumatoid arthritis (RA). RA-associated interstitial lung disease (RA-ILD) may be prevalent in up to 30% and clinically evident in 10% of patients with RA. Feasible methods to detect concomitant ILD in RA are warranted. Our objective is to determine the diagnostic accuracy of thoracic ultrasound (TUS) for ILD in patients with RA with respiratory symptoms, by using chest high-resolution CT (HRCT) as the reference standard. Further, we aim to evaluate the diagnostic accuracy for the promising blood biomarkers surfactant protein-D and microfibrillar-associated protein 4 in the detection of ILD in this group of patients. METHODS AND ANALYSIS: By use of a standardised 14 zone protocol patients suspected of having RA-ILD will undergo TUS as index test performed by a junior resident in rheumatology (BKS), who is certified by the European Respiratory Society in performing TUS assessments. Participants form a consecutive series of up to 80 individuals in total. The anonymised TUS images will be stored and scored by the junior resident as well as two senior rheumatologists, who have received training in TUS, and a TUS-experienced pulmonologist. HRCT will be used as the gold standard for ILD diagnosis (reference standard). The two basic measures for quantifying the diagnostic test accuracy of the TUS test are the sensitivity and specificity in comparison to the HRCT. ETHICS AND DISSEMINATION: Data will be collected and stored in the Research Electronic Data Capture database. The study is approved by the Committees on Health Research Ethics and the Danish Data Protection Agency. The project is registered at clinicaltrials.gov (NCT05396469, pre-results) and data will be published in peer-reviewed journals.

External validation of an artificial intelligence tool for radiographic knee osteoarthritis severity classification.

PURPOSE: To externally validate an artificial intelligence (AI) tool for radiographic knee osteoarthritis severity classification on a clinical dataset. METHOD: This retrospective, consecutive patient sample, external validation study used weight-bearing, non-fixed-flexion posterior-anterior knee radiographs from a clinical production PACS. The index test was ordinal Kellgren-Lawrence grading by an AI tool, two musculoskeletal radiology consultants, two reporting technologists, and two resident radiologists. Grading was repeated by all readers after at least four weeks. Reference test was the consensus of the two consultants. The primary outcome was quadratic weighted kappa. Secondary outcomes were ordinal weighted accuracy, multiclass accuracy and F1-score. RESULTS: 50 consecutive patients between September 24, 2019 and October 22, 2019 were retrospectively included (3 excluded) totaling 99 knees (1 excluded). Quadratic weighted kappa for the AI tool and the consultant consensus was 0.88 CI95% (0.82-0.92). Agreement between the consultants was 0.89 CI95% (0.85-0.93). Intra-rater agreements for the consultants were 0.96 CI95% (0.94-0.98) and 0.94 CI95% (0.91-0.96) respectively. For the AI tool it was 1 CI95% (1-1). For the AI tool, ordinal weighted accuracy was 97.8% CI95% (96.9-98.6 %). Average multiclass accuracy and F1-score were 84% (83/99) CI95% (77-91%) and 0.67 CI95% (0.51-0.81). CONCLUSIONS: The AI tool achieved the same good-to-excellent agreement with the radiology consultant consensus for radiographic knee osteoarthritis severity classification as the consultants did with each other.

[Clinical and diagnostic-imaging findings in patellofemoral instability].

Medical abortion with combined mifepristone and misoprostol is a highly effective, safe, and widely used method for medical termination of pregnancy. In this review, it is shown that self-testing with a urine human chorionic gonadotropin stix (detection limit greater than 25 IU/l) four weeks after administration of medication is a safe, practical, and cheap method to determine successful termination.

The fast-track outpatient clinic significantly decreases hospitalisation rates among polymyalgia rheumatica patients.

OBJECTIVES: This study aimed to investigate the hospitalisation rates and the reasons for hospitalisation in patients with polymyalgia rheumatica (PMR). Furthermore, it aimed to clarify the impact of a newly established Fast Track Clinic (FTC) approach on hospitalisation rates in connection with PMR diagnosis. METHODS: Patients diagnosed with PMR at South-West Jutland Hospital, Denmark, between 2013 and 2018 were included retrospectively. Only patients fulfilling the 2012 EULAR/ACR classification criteria were included in our cohort. An FTC for patients suspected of having PMR was established in the rheumatologic department of South-West Jutland Hospital in January 2018. RESULTS: Over 6 years (2013 to 2017), 254 patients were diagnosed with PMR, 56 of them while hospitalised. Hospitalised patients were more likely to have a higher initial CRP mean ± standard deviation (SD) 99.53 ± 59.36 vs 45.82 ± 36.96 mg/lt (p <  0.0001) and a shorter duration of symptoms (p = 0.0018). After implementing the FTC, a significant decrease in hospitalisation rates (from 20.4% to 3,5%) and inpatient days of care (mean ± SD 4.15 ± 3.1 vs 1 ± 0) were observed. No differences between the two groups were observed regarding clinical symptoms, laboratory values and initial prednisolone dose. CONCLUSION: A substantial number of patients are hospitalised in connection with the PMR diagnosis. The FTC approach can decrease the hospitalisation rates significantly among these patients. TRIAL REGISTRATION: Retrospectively registered.

Mechanical properties and UTE-T2* in Patellar tendinopathy: The effect of load magnitude in exercise-based treatment.

Loading intervention is currently the preferred management of tendinopathy, but to what extent different loading regimes influence the mechanical response in tendons is scarcely investigated. Therefore, the purposes of the investigation were to examine the effect of exercise interventions with either high or low load magnitude applied to the tendinopathic patellar tendon and the influence on its mechanical, material, and morphological properties. Forty-four men with chronic patellar tendinopathy were randomized to 12 weeks of exercising with either; 55% of 1RM throughout the period (MSR group) or 90% of 1RM (HSR group), and with equal total exercise volume in both groups. Mechanical (stiffness), material (T2* relaxation time), and morphological (cross-sectional area (CSA)) properties were assessed at baseline and after 12 weeks of intervention. MRI with ultra-short echo times (UTE) and T2*-mapping was applied to explore if T2* relaxation time could be used as a noninvasive marker for internal material alteration and early change thereof in response to intervention. There was no effect of HSR or MSR on the mechanical (stiffness), material (T2* relaxation time) or morphological (CSA) properties, but both regimes resulted in significant strength gain. In conclusion, there were no statistically superior effect of exercising with high (90%) compared to moderate (55%) load magnitude on the mechanical, material or morphological properties.

Magnetic Resonance T2 * Is Increased in Patients With Early-Stage Achilles and Patellar Tendinopathy.

BACKGROUND: T2 * mapping has proven useful in tendon research and may have the ability to detect subtle changes at an early stage of tendinopathy. PURPOSE: To investigate the difference in T2 * between patients with early tendinopathy and healthy controls, and to investigate the relationship between T2 * and clinical outcomes, tendon size, and mechanical properties. STUDY TYPE: Prospective cross-sectional. SUBJECTS: Sixty-five patients with early tendinopathy and 25 healthy controls. FIELD STRENGTH/SEQUENCE: Three Tesla, ultrashort time to echo magnetic resonance imaging. ASSESSMENT: Tendon T2 * was quantified using a monoexponential fitting algorithm. Clinical symptoms were evaluated using the Victorian Institute of Sports Assessment-Achilles/Patella (VISA-A/VISA-P). In vivo mechanical properties were measured using an ultrasound-based method that determined force and deformation simultaneously in tendons of patellar tendinopathy patients. STATISTICAL TESTS: A generalized linear model adjusted for age was applied to investigate the difference between patients and controls. In the two patient groups, linear regressions were applied to investigate the association between T2 * and tendon size, clinical outcomes, and biomechanical properties. RESULTS: There was a significant difference in T2 * between patients and healthy controls (204.8 [95% CI: 44.5-365.0] µsec, P < 0.05). There was a positive correlation between tendon size and T2 * for both Achilles (r = 0.72; P < 0.05) and patellar tendons (r = 0.53; P < 0.05). There was no significant correlation between VISA-A and T2 * (r = -0.2; P = 0.17) or VISA-P and T2 * (r = -0.5; P = 0.0504). Lastly, there was a negative correlation between modulus and T2 * (r = -0.51; P < 0.05). DATA CONCLUSIONS: T2 * mapping can detect subtle structural changes that translate to altered mechanical properties in early-phase tendinopathy. However, T2 * did not correlate with clinical scores in patients with early-phase Achilles and patellar tendinopathy. Thus, T2 * mapping may serve as a tool for early detection of structural changes in tendinopathy but does not necessarily describe the clinical severity of disease. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.

No Additive Clinical or Physiological Effects of Short-term Anti-inflammatory Treatment to Physical Rehabilitation in the Early Phase of Human Achilles Tendinopathy: A Randomized Controlled Trial.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in the treatment of Achilles tendinopathy, but whether they have any additive clinical effect on physical rehabilitation in the early phase of tendinopathy remains unknown. PURPOSE/HYPOTHESIS: To investigate whether an initial short-term NSAID treatment added to a physical rehabilitation program in the early phase of Achilles tendinopathy would have an additive effect. We hypothesized that the combination of NSAID and rehabilitation would be superior to rehabilitation alone. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 69 patients with early phase Achilles tendinopathy (lasting <3 months) were randomly assigned to either a naproxen group (7 days of treatment; 500 mg twice daily; n = 34) or a placebo group (7 days of placebo treatment; n = 35). Both groups received an identical 12-week physical rehabilitation program. The clinical outcome of the study was evaluated using the Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire and a numerical rating scale (NRS), and the physiological outcome was evaluated using ultrasonography, magnetic resonance imaging (MRI), and ultra-short time to echo T2* mapping MRI (UTE T2* MRI). Follow-up was performed at 1 week, 3 months, and 1 year. Time effects are presented as mean difference ± SEM. RESULTS: No significant differences were found between the 2 treatment groups for any of the outcome measures at any time point (P > .05). For the VISA-A score, a significant time effect was observed between baseline and 3-month follow-up (14.9 ± 2.3; P < .0001), and at 1-year follow-up, additional improvements were observed (6.1 ± 2.3; P < .01). Furthermore, the change in VISA-A score between baseline and 3-month follow-up was greater in patients with very short symptom duration (<1 month) at baseline compared with patients who had longer symptom duration (>2 months) (interaction between groups, 11.7 ± 4.2; P < .01). Despite clinical improvements, total weekly physical activity remained lower compared with preinjury levels at 3 months (-2.7 ± 0.5 h/wk; P < .0001) and 1 year (-3.0 ± 0.5 h/wk; P < .0001). At baseline, ultrasonography showed increased thickness (0.12 ± 0.03 cm; P < .0001) and vascularity (0.3 ± 0.1 cm2; P < .005) on the tendinopathic side compared with the contralateral side, but no changes over time were observed for ultrasonography, MRI, or UTE T2* MRI results. CONCLUSION: Clinical symptoms in early tendinopathy improved with physical rehabilitation, but this improvement was not augmented with the addition of NSAID treatment. Furthermore, this clinical recovery occurred in the absence of any measurable structural alterations. Finally, clinical improvements after a physical rehabilitation program were greater in patients with very short symptom duration compared with patients who had longer symptom duration. REGISTRATION: NCT03401177 (ClinicalTrials.gov identifier) and BFH-2016-019 (Danish Data Protection Agency).

Positional changes in lumbar disc herniation during standing or lumbar extension: a cross-sectional weight-bearing MRI study.

OBJECTIVES: To investigate biomechanical changes in lumbar disc herniations. METHODS: Patients with lumbar disc herniation verified on a 1.5-3-T magnetic resonance imaging (MRI) scanner were imaged in a weight-bearing 0.25-T MRI scanner in (1) standing position, (2) conventional supine position with relative lumbar flexion, and (3) supine position with a forced lumbar extension by adding a lumbar pillow. The L2-S1 lordosis angle, the disc cross-sectional area, the disc cross-sectional diameter, and the spinal canal cross-sectional diameter were measured for each position. Disc degeneration and nerve root compression were graded, and the pain intensity was reported during each scan position. RESULTS: Forty-three herniated discs in 37 patients (36.7 ± 11.9 years) were analyzed in each position. The L2-S1 lumbar angle increased in the standing position (mean difference [MD]: 5.61°, 95% confidence interval [95% CI]: 3.44 to 7.78) and with the lumbar pillow in the supine position (MD: 14.63°, 95% CI: 11.71 to 17.57), both compared with the conventional supine position. The herniated disc cross-sectional area and diameter increased during standing compared with during conventional supine position. No changes were found in the spinal canal cross-sectional diameter between positions. Higher nerve root compression grades for paracentral herniations were found during standing compared with during conventional supine position. This was neither found with a lumbar pillow nor for central herniations in any position compared with conventional supine. CONCLUSION: Disc herniations displayed dynamic behavior with morphological changes in the standing position, leading to higher nerve root compression grades for paracentral herniated discs. KEY POINTS: • Lumbar herniated discs increased in size in the axial plane during standing. • Increased nerve root compression grades for paracentral herniated discs were found during standing. • Weight-bearing MRI may increase the diagnostic sensitivity of nerve root compression in lumbar disc herniations.

UTE T2* mapping of tendinopathic patellar tendons: an MRI reproducibility study.

BACKGROUND: There is currently a lack of imaging modalities that can be used as a sensitive measure in tendinopathy. Recent findings suggest the applicability of ultra-short echo time (UTE) magnetic resonance imaging (MRI) T2* mapping in tendons, but the reproducibility remains unknown. PURPOSE: To evaluate test-retest reproducibility of UTE MRI T2* mapping of tendinopathic patellar tendons and to evaluate the intra- and inter-observer reproducibility of the measurement. MATERIAL AND METHODS: Fifteen patients with chronic patellar tendinopathy were evaluated with UTE MRI twice in a 3.0-T scanner on the same day. Manual segmentation of the patellar tendon was performed by two blinded investigators and automated T2*map reconstruction was performed in custom-made software. RESULTS: There was a significant and numerically small difference in test-retest T2* values (T2*meandiff = 0.06 ± 0.07 ms ≈ 3.7%; P = 0.006) with an ICC = 0.91 (95% confidence interval [CI] 0.58-0.98; typical error of 3.0%). The intra- and inter-observer reproducibility showed no significant bias (P = 0.493 and P = 0.052), and generally substantial reproducibility was demonstrated for T2* (intra-observer ICC = 0.99; 95% CI 0.98-1.00 and inter-observer ICC = 0.99; 95% CI 0.96-1.00, and typical error 1.3% and 1.3%, respectively). CONCLUSION: These data demonstrate a small bias between repeated measurements for UTE T2*, but with a very low associated mean difference (3.7%) between the two tests. The high ICC values and low typical error % demonstrate reproducibility of repeated T2*-mapping sessions. Further, the method showed substantial intra- and inter-observer reproducibility for T2* values proving feasibility for use of UTE T2* mapping in research and clinical practice.

Early development of tendinopathy in humans: Sequence of pathological changes in structure and tissue turnover signaling.

Overloading of tendon tissue with resulting chronic pain (tendinopathy) is a common disorder in occupational-, leisure- and sports-activity, but its pathogenesis remains poorly understood. To investigate the very early phase of tendinopathy, Achilles and patellar tendons were investigated in 200 physically active patients and 50 healthy control persons. Patients were divided into three groups: symptoms for 0-1 months (T1), 1-2 months (T2) or 2-3 months (T3). Tendinopathic Achilles tendon cross-sectional area determined by ultrasonography (US) was ~25% larger than in healthy control persons. Both Achilles and patellar anterior-posterior diameter were elevated in tendinopathy, and only later in Achilles was the width increased. Increased tendon size was accompanied by an increase in hypervascularization (US Doppler flow) without any change in mRNA for angiogenic factors. From patellar biopsies taken bilaterally, mRNA for most growth factors and tendon components remained unchanged (except for TGF-beta1 and substance-P) in early tendinopathy. Tendon stiffness remained unaltered over the first three months of tendinopathy and was similar to the asymptomatic contra-lateral tendon. In conclusion, this suggests that tendinopathy pathogenesis represents a disturbed tissue homeostasis with fluid accumulation. The disturbance is likely induced by repeated mechanical overloading rather than a partial rupture of the tendon.

Weight-bearing MRI of the Lumbar Spine: Technical Aspects.

Magnetic resonance imaging (MRI) has an established role in the assessment of degenerative musculoskeletal conditions. However, conventional supine MRI findings often correlate poorly with clinical findings. Some patients experience accentuated back pain in the weight-bearing position. Therefore, supine MRI may underestimate the severity of degenerative spine findings. To try and improve the clinical validity of spine imaging, axial loading devices have been used with conventional supine MR imaging to simulate loading of the upright spine. More recently, upright weight-bearing MRI systems (0.25-0.6 T) were introduced, allowing images to be obtained in the standing or seated weight-bearing position and even during upright flexion or extension, rotation, or bending. Some scanners even enable capturing of real-time spinal movement. This review addresses the technical aspects and potential challenges of weight-bearing MRI, both in clinical practice and research.

Weight-bearing MRI of the Lumbar Spine: Spinal Stenosis and Spondylolisthesis.

Symptoms of degenerative lumbar spinal stenosis include back pain, radiculopathy, claudication, and muscular fatigue that tend to be predominant in the standing position or during walking. Lumbar spondylolisthesis is also a well-known cause of spinal stenosis, lateral recess, and neural foraminal narrowing that tends to become more severe in the upright position. This indicates a functional positional component of both spinal stenosis and spondylolisthesis. Lumbar spinal stenosis and spondylolisthesis are typically evaluated by magnetic resonance imaging (MRI) performed in the supine position with a pillow under the patient's lower limbs that slightly flexes the lumbar spine and ameliorates symptoms. Because these two entities tend to be aggravated in the upright position, it seems rational to also consider performing diagnostic imaging in these patients in the upright position. This article reviews the use of weight-bearing MRI for lumbar spinal stenosis and spondylolisthesis.