Changes in lumbar spondylolisthesis on axial-loaded MRI: do they reproduce the positional changes in the degree of olisthesis observed on X-ray images in the standing position?

Background Context: Axial-loaded magnetic resonance imaging (MRI) can partially simulate the lumbar spine in patients in a standing position and potentially provides additional imaging findings that cannot be obtained with conventional MRI in the clinical assessment of patients with degenerative lumbar disease. Previous studies have shown that axial-loaded MRI demonstrates a significant reduction in the size of the dural sac compared with conventional MRI. However, there has been no study to compare the degree of olisthesis among conventional MRI, axial-loaded MRI, and upright X-ray imaging in patients with degenerative spondylolisthesis (DS).

Chondrogenic and fibrotic process in the ligamentum flavum of patients with lumbar spinal canal stenosis.

Study Design: A histological, biological, and immunohisto-chemical study of human lumbar ligamentum flavum.

Objective: To analyze changes in the hypertrophied ligamentum flavum and clarify their etiology.

Summary Of Background Data: Hypertrophy of the ligamentum flavum has been considered a major contributor to the development of lumbar spinal canal stenosis (LSCS).

A review of biomechanics of the shoulder and biomechanical concepts of rotator cuff repair.

In this article, we describe the basic knowledge about shoulder biomechanics, which is thought to be useful for surgeons. Some clinical reports have described that the excellent outcome after cuff repair without acromioplasty and a limited acromioplasty might be enough for subacromial decompression. It was biomechanically demonstrated that a 10-mm medial shift of the tendon repair site has a minimum effect on biomechanics.

Simultaneous evaluation of articular cartilage and subchondral bone from immobilized knee in rats by photoacoustic imaging system.

Background: Osteoarthritis is not only a disease of articular cartilage, but also of subchondral bone. It is difficult for ultrasound to evaluate subchondral bone because of permeability. This study aimed to evaluate sequential osteoarthritic changes of articular cartilage and subchondral bone from immobilized knees in rats with a photoacoustic (PA) imaging system.

Schwann cell transplantation for spinal cord injury repair: its significant therapeutic potential and prospectus.

Transplantation of Schwann cells (SCs) is a promising therapeutic strategy for spinal cord repair. The introduction of SCs into the injured spinal cord has been shown to reduce tissue loss, promote axonal regeneration, and facilitate myelination of axons for improved sensorimotor function. The pathology of spinal cord injury (SCI) comprises multiple processes characterized by extensive cell death, development of a milieu inhibitory to growth, and glial scar formation, which together limits axonal regeneration.

Feasibility assessment of shear wave elastography to rotator cuff muscle.

Pre-surgical measurement of supraspinatus muscle extensibility is important for rotator cuff repair. The purpose of the present study was to explore the potential feasibility of a shear wave ultrasound elastography (SWE)-based method, combined with B-mode ultrasound, to measure the in vivo stiffness of the supraspinatus muscle non-invasively and thus obtain key information about supraspinatus muscle extensibility. Our investigation comprised two steps.

Efficacy of methotrexate and tumor necrosis factor inhibitors in Japanese patients with active psoriatic arthritis.

Objective: The aim of this study was to assess the efficacy of oral methotrexate and tumor necrosis factor inhibitors in Japanese patients with active psoriatic arthritis.

Methods: We retrospectively investigated 51 patients who fulfilled the ClASsification criteria for Psoriatic ARthritis (CASPAR) criteria for the efficacy of tumor necrosis factor inhibitors and methotrexate. We assessed the visual analog scale score, psoriasis area and severity index score, C-reactive protein-based disease activity score in 28 joints (DAS28), swollen joint count (0-66), tender joint count (0-68), health assessment questionnaire score, C-reactive protein level, erythrocyte sedimentation rate, and matrix metalloproteinase 3, at both baseline and week 24.

In-vitro biomechanical evaluation of stress shielding and initial stability of a low-modulus hip stem made of β type Ti-33.6Nb-4Sn alloy.

Stress shielding-related proximal femoral bone loss after total hip arthroplasty occurs because of the different stiffness of metallic alloy stems and host bone. To overcome this, we fabricated a low-modulus cementless hip stem from β-type Ti-33.6Nb-4Sn alloy (TNS).

Low-energy extracorporeal shock wave therapy promotes vascular endothelial growth factor expression and improves locomotor recovery after spinal cord injury.

Object: Extracorporeal shock wave therapy (ESWT) is widely used for the clinical treatment of various human diseases. Recent studies have demonstrated that low-energy ESWT upregulates the expression of vascular endothelial growth factor (VEGF) and promotes angiogenesis and functional recovery in myocardial infarction and peripheral artery disease. Many previous reports suggested that VEGF produces a neuroprotective effect to reduce secondary neural tissue damage after spinal cord injury (SCI).

Comparison of muscle activity in the empty-can and full-can testing positions using 18 F-FDG PET/CT.

Background: There has been much controversy over specific tests for diagnosis of supraspinatus tendon tear. The aim of this study was to evaluate the metabolic activity of the deltoid and rotator cuff muscles while maintaining the full-can and empty-can testing positions using 2-deoxy-2-[18 F]fluoro-D-glucose (18 F-FDG) positron emission tomography (PET)/computed tomography (CT).

Methods: Ten healthy volunteers without shoulder pain or diabetes mellitus participated in this study.

In vivo measurement of rotator cuff tendon strain with ultrasound elastography: an investigation using a porcine model.

Objectives: To clarify the relationship between the strain ratio measured by ultrasound elastography and the mechanical properties of the tendon measured by a universal testing machine. We also attempted to determine the effect of the type and depth of soft tissue overlying the tendon on the elastographic measurement.

Methods: Twelve fresh porcine shoulders were prepared.

Reoperation rates after fenestration for lumbar spinal canal stenosis: a 20-year period survival function method analysis.

Purpose: Fenestration is the gold standard surgery for lumbar spinal canal stenosis in Japan. Several previous studies have analyzed the reoperation rates in large numbers of patients undergoing several surgical procedures such as laminectomy with or without instrumented spinal fusion; however, there have been few studies focusing solely on fenestration. The purpose of this study was to calculate the reoperation rates after fenestration using the survival function method.

Association of reduced type IX collagen gene expression in human osteoarthritic chondrocytes with epigenetic silencing by DNA hypermethylation.

Objective: To investigate whether the changes in collagen gene expression in osteoarthritic (OA) human chondrocytes are associated with changes in the DNA methylation status in the COL2A1 enhancer and COL9A1 promoter.

Methods: Expression levels were determined using quantitative reverse transcription-polymerase chain reaction, and the percentage of DNA methylation was quantified by pyrosequencing. The effect of CpG methylation on COL9A1 promoter activity was determined using a CpG-free vector; cotransfections with expression vectors encoding SOX9, hypoxia-inducible factor 1α (HIF-1α), and HIF-2α were carried out to analyze COL9A1 promoter activities in response to changes in the methylation status.

Ultrasound elastography-based assessment of the elasticity of the supraspinatus muscle and tendon during muscle contraction.

Background: Although elasticity of the supraspinatus muscle and tendon is a useful parameter to represent the conditions of the supraspinatus muscle and tendon, assessment of the elasticity in clinical settings has not been established. The purpose of this study was to determine the elasticity of the supraspinatus muscle belly and tendon under different muscle contraction conditions using ultrasound real-time tissue elastography (RTE).

Methods: Twenty-three healthy individuals participated in this study.

Radiolucent zone of the patella following total knee arthroplasty without patellar resurfacing.

Background: The radiolucent zones in the patella are sometimes observed in patients who have undergone total knee arthroplasty (TKA) without patellar resurfacing. On the basis of radiological findings from our clinical experience, we hypothesize that the pathogenesis of this lesion may be similar to that of the lesions of spontaneous osteonecrosis, and this lesion may be due to both osteoporosis and stress concentration. The present study aimed to determine the incidence of the radiolucent zone after TKA without patellar resurfacing.

Contribution of oxidative stress to the degeneration of rotator cuff entheses.

Background: Rotator cuff degeneration is one of the multiple factors that lead to rotator cuff tears; however, the precise mechanism of such degeneration still remains unclear. In this study, we investigated the supraspinatus tendon enthesis to clarify the link between rotator cuff degeneration and oxidative stress in antioxidant enzyme superoxide dismutase 1 (Sod1)-deficient mice (Sod1(-/-)).

Methods: The supraspinatus tendon and humeral head were isolated and fixed to prepare histologic sections from wild-type and Sod1(-/-) male mice at 20 weeks of age.

Venous thromboembolism after elective shoulder surgery: a prospective cohort study of 175 patients.

Background: The purpose of this study was to investigate the incidence of venous thromboembolism (VTE) after elective arthroscopic shoulder surgery.

Materials And Methods: One hundred seventy-five consecutive patients who underwent arthroscopic shoulder surgery were enrolled (mean age, 61 years). Patients who had VTE preoperatively and underwent trauma surgery or arthroplasty were excluded.

Oxygen tension affects lubricin expression in chondrocytes.

We assessed the effects of oxygen tension on lubricin expression in bovine chondrocytes and cartilage explants and a role for hypoxia-inducible transcription factor (HIF)-1α in regulating lubricin expression was investigated using a murine chondroprogenitor cell line, ATDC5, and bovine chondrocytes isolated from superficial and middle/deep zones of femoral cartilage. ATDC5 cells and bovine chondrocytes were cultured in micromass under different oxygen tensions (21%, 5%, and 1%). ATDC5 cells and middle/deep zone chondrocytes that initially had low lubricin expression levels were also cultured with or without transforming growth factor (TGF)-β1.

Measurement of the Glenoid Track In Vivo as Investigated by 3-Dimensional Motion Analysis Using Open MRI.

Background: A Hill-Sachs lesion is a common injury associated with anterior glenohumeral instability, and a Hill-Sachs lesion that engages with the anterior glenoid rim is 1 factor related to recurrent instability. In a cadaveric study in 2007, a new concept, the "glenoid track," was proposed to evaluate the risk of engagement of Hill-Sachs lesions with the glenoid.

Purpose: To investigate the glenoid track in vivo using a custom-developed noninvasive motion analysis system.

Effects of intra-articular steroid injection before pan-capsular release in patients with refractory frozen shoulder.

Purpose: The purpose of the study was to retrospectively determine the effects of intra-articular steroid injection on the clinical outcome of patients who underwent arthroscopic pan-capsular release for refractory frozen shoulder.

Methods: Between 2000 and 2010, 34 patients (20 males, 14 females) who underwent an arthroscopic pan-capsular release for frozen shoulder were included. Intra-articular steroid injections were administered from April 2006, and just before surgery and at the final follow-up, ranges of motion (ROM) and scores of the Shoulder Rating Scale of the University of California, Los Angeles (UCLA) scoring system were evaluated.

Medial meniscus tear morphology and related clinical symptoms in patients with medial knee osteoarthritis.

Purpose: The objective of this study was to examine the association between clinical symptoms and arthroscopic meniscal findings in patients with early to moderate medial knee osteoarthritis.

Methods: One hundred and four patients (110 knees) were selected from a group of 132 patients (140 knees) aged ≥50 years who underwent arthroscopic surgery for medial meniscal tears. Inclusion criteria were as follows: (a) medial knee osteoarthritis and (b) simple medial meniscal tears extending to ≥1/4 of the meniscal margin.

Muscle activity pattern of the shoulder external rotators differs in adduction and abduction: an analysis using positron emission tomography.

Background: The muscle activity pattern during shoulder external rotation has not been fully clarified. This study aimed to determine the activities involved in external rotation in the adducted and abducted positions using positron emission tomography (PET).

Methods: Seven healthy volunteers underwent PET examinations after performing external rotation using an elastic band at both 0° and 90° of shoulder abduction in the frontal plane.

ISAKOS upper extremity committee consensus statement on the need for diversification of the Rockwood classification for acromioclavicular joint injuries.

Optimal treatment for the unstable acromioclavicular (AC) joint remains a highly debated topic in the field of orthopaedic medicine. In particular, no consensus exists regarding treatment of grade III injuries, which are classified according to the Rockwood classification by disruption of both the coracoclavicular and AC ligaments. The ISAKOS Upper Extremity Committee has provided a more specific classification of shoulder pathologies to enhance the knowledge on and clinical approach to these injuries.

Combination of engineered Schwann cell grafts to secrete neurotrophin and chondroitinase promotes axonal regeneration and locomotion after spinal cord injury.

Transplantation of Schwann cells (SCs) is a promising therapeutic strategy for spinal cord repair. SCs introduced into lesions support axon regeneration, but because these axons do not exit the transplant, additional approaches with SCs are needed. Here, we transplanted SCs genetically modified to secrete a bifunctional neurotrophin (D15A) and chondroitinase ABC (ChABC) into a subacute contusion injury in rats.