Severity of Bone Marrow Edema on MRI Predicts the Diagnostic Potential of Foot Joint Injections.

Background: Intraarticular steroid and local anesthetic injections are often performed for foot pain. Localizing the exact joint acting as a pain generator in foot pain is eminent for optimal and cost-effective treatment. Because of the complex anatomy of the foot with multiple small articulations side by side, this can be challenging.

Modic type 2 changes are fibroinflammatory changes with complement system involvement adjacent to degenerated vertebral endplates.

Background: Vertebral endplate signal intensity changes visualized by magnetic resonance imaging termed Modic changes (MC) are highly prevalent in low back pain patients. Interconvertibility between the three MC subtypes (MC1, MC2, MC3) suggests different pathological stages. Histologically, granulation tissue, fibrosis, and bone marrow edema are signs of inflammation in MC1 and MC2.

Learning how to perform ultrasound-guided interventions with and without augmented reality visualization: a randomized study.

Objectives: Augmented reality (AR), which entails overlay of in situ images onto the anatomy, may be a promising technique for assisting image-guided interventions. The purpose of this study was to investigate and compare the learning experience and performance of untrained operators in puncture of soft tissue lesions, when using AR ultrasound (AR US) compared with standard US (sUS).

Methods: Forty-four medical students (28 women, 16 men) who had completed a basic US course, but had no experience with AR US, were asked to perform US-guided biopsies with both sUS and AR US, with a randomized selection of the initial modality.

The Great Mimickers of Spinal Pathology.

Back pain is one of the leading causes of health costs worldwide, particularly because of the further increased aging population. After clinical examination, spinal imaging is of utmost importance in many patients to reach the correct diagnosis. There are many imaging pitfalls and mimickers of spinal pathology on radiographs, magnetic resonance imaging, and computed tomography.

Role of C-reactive protein in the bone marrow of Modic type 1 changes.

Modic type 1 changes (MC1) are vertebral bone marrow lesions and associate with low back pain. Increased serum C-reactive protein (CRP) has inconsistently been associated with MC1. We aimed to provide evidence for the role of CRP in the tissue pathophysiology of MC1 bone marrow.

Atypical patterns of spinal segment degeneration in patients with abdominal aortic aneurysms.

Purpose: Abdominal aortic aneurysms (AAAs) affect the vascular perfusion of the lumbar spine. The treatment of AAAs with endovascular aortic aneurysm repair (EVAR) completely occludes the direct vascular supply to the lumbar spine. We hypothesized that patients with AAA who undergo EVAR show a different pattern of spinal degeneration than individuals without AAA.

Spondylophyte classification based on biomechanical effects on segmental stiffness.

Background Context: The biomechanical impact of spondylophytes on segmental stiffness is largely unknown, despite their high incidence.

Purpose: The aim of this study was to quantify the biomechanical contribution according to location and cranio-caudal extent of spondylophytes and to create a clinically applicable radiological classification system.

Study Design: Biomechanical cadaveric study.

Added value of combined acromiohumeral distance and critical shoulder angle measurements on conventional radiographs for the prediction of rotator cuff pathology.

Purpose: To investigate the role of acromiohumeral distance (AHD) and critical shoulder angle (CSA) measurements from conventional radiographs (CR) in isolation and combined (prognostic index PI) as predictors of full thickness rotator cuff tendon tears (RCT) and critical fatty degeneration (CFD; i.e. as much fat as muscle).

Operator independent reliability of direct augmented reality navigated pedicle screw placement and rod bending.

Background: AR based navigation of spine surgeries may not only provide accurate surgical execution but also operator independency by compensating for potential skill deficits. "Direct" AR-navigation, namely superposing trajectories on anatomy directly, have not been investigated regarding their accuracy and operator's dependence.Purpose of this study was to prove operator independent reliability and accuracy of both AR assisted pedicle screw navigation and AR assisted rod bending in a cadaver setting.

Hydrostatic integrity of the intervertebral disc assessed by MRI.

Hydrostatic integrity of the intervertebral disc (IVD) is lost during the process of degeneration. Invasive pressure profilometry (IPP) can quantify it, however, is not applicable for clinical use. We aimed to investigate correlations between IPP and MRI findings to assess non-invasive MRI based methods for prediction of hydrostatic integrity of the intervertebral disc.

MRI appearance of adjunct surgical material used in spine surgery.

Background Context: Early postoperative MR images are frequently necessary after spine surgery. The appearance of commonly used adjunct hemostatic agents and dural sealants in MR images has not been systematically evaluated.

Purpose: The purpose of this experimental study was to systematically analyze and describe the characteristics of the most commonly applied hemostatic agents and dural sealants in spine surgery on early postoperative MR images.

Patient-specific template-guided versus standard freehand lumbar pedicle screw implantation: a randomized controlled trial.

Objective: Patient-specific template-guided (TG) pedicle screw placement currently achieves the highest reported accuracy in cadaveric and early clinical studies, with reports of reduced use of radiation and less surgical time. However, a clinical randomized controlled trial (RCT) eliminating potential biases is lacking. This study compares TG and standard freehand (FH) pedicle screw insertion techniques in an RCT.

Intervertebral disc degeneration relates to biomechanical changes of spinal ligaments.

Background Context: The ligamentum flavum (LF), the inter- and supraspinous ligament (ISL&SSL) and the intertransverse ligament (ITL) are relevant spinal structures for segmental stability. The biomechanical effect of degeneration and aging on their biomechanical properties remains largely unknown.

Purpose: The aim of this study was to assess the material properties of the ITL, ISL&SSL and LF and to correlate parameters of biomechanical function with LF-thickness, intervertebral disc (IVD) degeneration and age.

Biomechanical Contributions of Spinal Structures with Different Degrees of Disc Degeneration.

Study Design: Biomechanical cadaveric study.

Objective: The aim of this study was to evaluate the effect of degeneration on biomechanical properties of the passive structures of the lumbar spine.

Summary Of Background Data: Although the load apportionment among the passive structures in healthy spines follows well-defined contribution patterns, it remains unknown how this load distribution and sagittal preload changes by degenerative processes of the intervertebral disc (IVD).

Diurnal T2-changes of the intervertebral discs of the entire spine and the influence of weightlifting.

The purpose was to study if (1) diurnal changes occur in the entire spine and if (2) intervertebral discs (IVDs) of weightlifters (WL) have decreased baseline T2-values in the morning as well as (3) increased diurnal changes throughout the day. This prospective cohort study investigated healthy volunteers between 2015 and 2017. WL were required to have participated in weightlifting ≥ 4×/week for ≥ 5 years, while non-weightlifters (NWL) were limited to < 2×/week for ≥ 5 years.

Synthetic Biphasic Scaffolds versus Microfracture for Articular Cartilage Defects of the Knee: A Retrospective Comparative Study.

Objective: The purpose of this study was to compare the results of a biphasic synthetic scaffold (TruFit, Smith & Nephew) to microfracture for the treatment of knee cartilage defects and identify patient- and lesion-specific factors that influence outcomes.

Design: Prospectively collected data from 132 patients (mean age, 41.8 years; 69% male) with isolated chondral or osteochondral femoral defects treated with biphasic synthetic scaffolds ( = 66) or microfracture ( = 66) were reviewed.

Ultrasound-guided interventions with augmented reality in situ visualisation: a proof-of-mechanism phantom study.

Background: Ultrasound (US) images are currently displayed on monitors, and their understanding needs good orientation skills. Direct overlay of US images onto the according anatomy is possible with augmented reality (AR) technologies. Our purpose was to explore the performance of US-guided needle placement with and without AR in situ US viewing.

Accuracy of Patient-Specific Template-Guided Versus Freehand Cervical Pedicle Screw Placement from C2 to C7: A Randomized Cadaveric Study.

Background: Dorsal spinal instrumentation with cervical pedicle screws (CPS) and rod constructs is performed for numerous pathologies of the cervical spine, although technically demanding. Screw misplacement is biomechanically disadvantageous and carries the risk of neurovascular sequelae. The aim of this study was to assess the accuracy of patient-specific, template-guided CPS placement from C2 to C7 compared with the freehand technique.

Quantitative MRI of visually intact rotator cuff muscles by multiecho Dixon-based fat quantification and diffusion tensor imaging.

Background: Quantitative MRI allows assessment of shoulder rotator cuff (RC) muscles by Dixon MR sequences with calculation of fractional fat content (FF%) maps and diffusion tensor imaging (DTI) including tractography.

Purpose: To compare FF% and DTI derived parameters among visually intact RC muscles, to compare 2D with 3D DTI measurements and to establish normative values.

Study Type: Prospective.

Value of standard radiographs, computed tomography, and magnetic resonance imaging of the lumbar spine in detection of intraoperatively confirmed pedicle screw loosening-a prospective clinical trial.

Background Context: Pedicle screw loosening is common after spinal fusion and can be associated with pseudoarthrosis and pain. With suspicion of screw loosening on standard radiographs, CT is currently considered the advanced imaging modality of choice. MRI with new metal artifact reduction techniques holds potential to be sensitive in detection of screw loosening.

3-T MRI implant safety: heat induction with new dual-channel radiofrequency transmission technology.

We aimed to investigate whether different transmission settings of the dual-transmit technology may influence the amount of heat induction around an implant material dependent on its location within the magnetic field. Metallic hip implants were positioned in the magnet of a 3-T scanner at various lateral offset positions in relation to the magnetic axis in a body-phantom tank filled with polyacrylic acid gel. The temperature increase close to the implants was measured during turbo spin-echo scanning using dual-channel parallel radiofrequency (RF) transmission with circular in comparison to elliptic RF polarization.

Material-Dependent Implant Artifact Reduction Using SEMAC-VAT and MAVRIC: A Prospective MRI Phantom Study.

Objective: The aim of this study was to compare the degree of artifact reduction in magnetic resonance imaging achieved with slice encoding for metal artifact correction (SEMAC) in combination with view angle tilting (VAT) and multiacquisition variable resonance image combination (MAVRIC) for standard contrast weightings and different metallic materials.

Methods: Four identically shaped rods made of the most commonly used prosthetic materials (stainless steel, SS; titanium, Ti; cobalt-chromium-molybdenum, CoCr; and oxidized zirconium, oxZi) were scanned at 3 T. In addition to conventional fast spin-echo sequences, metal artifact reduction sequences (SEMAC-VAT and MAVRIC) with varying degrees of artifact suppression were applied at different contrast weightings (T1w, T2w, PDw).

The intervertebral disc, the endplates and the vertebral bone marrow as a unit in the process of degeneration.

Objectives: The association of disc degeneration (DD) and vertebral endplate degeneration (EPD) is still not well understood. This study aimed to find segmental predictive risk factors for DD and EPD and to illuminate associations of the disc, endplate and bone marrow changes in the process of degeneration.

Methods: After institutional review board approval, 450 lumbar levels, followed up with MRI for at least 4 years, were retrospectively graded for DD according to Pfirrmann (PFG), for EPD according to the endplate score (EPS) and according to the presence, extension and type of Modic changes (MC).

Reliability of postoperative MR imaging in the determination of level and side of lumbar spinal decompression surgery.

Background Magnetic resonance imaging (MRI) is the diagnostic modality of choice in defining soft tissue compromise of the spinal canal. Purpose To evaluate the reliability of postoperative MRI in the determination of level and side of lumbar spinal decompression surgery, investigated by two reviewers, in different levels of training and specialization. Material and Methods Postoperative MR images of 86 patients who underwent spinal decompression (single level, n = 70; multilevel, n = 16; revision decompression, n = 9) were reviewed independently by an experienced musculoskeletal radiologist and a fourth-year orthopedic surgery resident.

Accuracy of patient-specific template-guided vs. free-hand fluoroscopically controlled pedicle screw placement in the thoracic and lumbar spine: a randomized cadaveric study.

Purpose: Dorsal spinal instrumentation with pedicle screw constructs is considered the gold standard for numerous spinal pathologies. Screw misplacement is biomechanically disadvantageous and may create severe complications. The aim of this study was to assess the accuracy of patient-specific template-guided pedicle screw placement in the thoracic and lumbar spine compared to the free-hand technique with fluoroscopy.