Validation of compositional MRI from a histological standpoint: Advantages of three-dimensional T1ρ mapping for quantitative evaluation of articular cartilage.

PURPOSE: We aimed to investigate the relationship between quantitative evaluation by compositional MRI, including T1ρ, and histological and macroscopic assessments, to verify the validity of compositional MRI, and examine the relationship between compositional MRI evaluation reconstructed in three dimensions (3D) and histological and visual assessments. METHOD: Twenty-seven patients with knee osteoarthritis underwent T1ρ and T2 magnetic resonance imaging (MRI). Histological and gross tissue evaluations were performed on the excised bone sections of total knee arthroplasty. Semi-quantitative histological evaluation of tissue changes were assessed by measuring the optical density of digitally captured safranin O-stained and Collagen type II antibody-stained paraffin sections. Macroscopic cartilage severity was determined on a 5-grade scale (G0-G5). T1ρ and T2 values (3D and 2D), and their correlation with each of these parameters were investigated. RESULTS: 3D T1 ρ is negatively correlated with histological evaluations and positively correlated with visual assessments. Only 3D T1ρ values correlated with histological quantitative evaluation (Safranin-O staining; r = -0.53, P = 0.014, Collagen type II antibody staining; r = -0.60, P = 0.019). 2D T1ρ and 3D, 2D T2 values did not correlate with histological evaluation results. Macroscopic cartilage severity grade correlated with all T1ρ and T2 values (3D T1ρ; r = 0.61, P < 0.001, 2D T1ρ; r = 0.52, P < 0.001, 3D T2; r = 0.33, P = 0.045, 2D T2; r = 0.41, P = 0.01). CONCLUSIONS: 3D T1ρ mapping reflects the changes in the molecular structure of the cartilage matrix that occur in arthropathic changes and may be an effective tool for detecting cartilage degeneration.

A pilot study with 3D T1ρ-mapping for quantitative evaluation of cartilage after open-wedge high tibial osteotomy.

PURPOSE: To evaluate the recently developed three-dimensional (3D) T1ρ-mapping technique for the quantitative evaluation of cartilage changes after open-wedge high tibial osteotomy (OWHTO). METHOD: Eleven patients with medial knee osteoarthritis and spontaneous osteonecrosis of the medial femoral condyle underwent T1ρ magnetic resonance imaging. The full-thickness cartilage of the medial femoral condyle (MFC), lateral femoral condyle, medial tibial condyle, and lateral tibial condyle, and the trochlea and patella were set as regions of interest; mean T1ρ values were calculated using two-dimensional (2D) and 3D analyses. The state of cartilage injury was evaluated using the International Cartilage Repair Society grading system (ICRS grade). T1ρ values before OWHTO and after hardware removal were compared using the Wilcoxon signed-rank test. The correlation between T1ρ values and the ICRS grade was explored using the Spearman rank correlation coefficient. RESULTS: Cartilage repair at the MFC was observed in a high proportion of patients (82%), but 2D analysis did not reveal a significant difference after surgery at any site. In contrast, 3D analysis revealed a significant decrease in T1ρ values after surgery at the MFC (before surgery: 44.1 ms; after surgery: 38.9 ms; p = 0.016), but no significant difference at any other site. In the MFC, there was a positive correlation between 3D T1ρ values and arthroscopic findings before and after surgery (rs = 0.62, p < 0.01), which was absent from the 2D T1ρ values. CONCLUSIONS: 3D T1ρ-mapping may be an effective tool for detecting changes in cartilage quality after OWHTO.

Severe complication subsequent to surgical site infection after cervical laminoplasty: a case report.

INTRODUCTION: Surgical site infections (SSI) following spinal surgery can result in serious complications. Although early detection and intensive care are essential to minimize possible sequelae, more than one surgical intervention is required to alleviate the infection in some cases. CASE PRESENTATION: A 66-year-old man with long-standing Parkinson's disease (PD) developed SSIs after cervical laminoplasty. Despite surgical debridement and irrigation, his neurological status worsened severely and anterior infectious involvement at the C4-5 level was identified by magnetic resonance imaging. He underwent another urgent surgery for anterior debridement and iliac bone grafting. His laboratory results gradually normalized with antibiotic therapy, and his neurological status improved. One year after surgery, he was ambulatory with walker assistance. However, his right hand remained difficult to control with significant sensory loss and numbness. DISCUSSION: To our knowledge, this is the first case of SSI that extended rapidly to the anterior side despite immediate and intensive treatment in a patient with PD after laminoplasty. During SSI treatment, meticulous observation should be performed to check for exacerbations.

RT-qPCR analyses on the osteogenic differentiation from human iPS cells: an investigation of reference genes.

Reverse transcription quantitative PCR (RT-qPCR) is used to quantify gene expression and require standardization with reference genes. We sought to identify the reference genes best suited for experiments that induce osteogenic differentiation from human induced pluripotent stem cells. They were cultured in an undifferentiated maintenance medium and after confluence, further cultured in an osteogenic differentiation medium for 28 days. RT-qPCR was performed on undifferentiation markers, osteoblast and osteocyte differentiation markers, and reference gene candidates. The expression stability of each reference gene candidate was ranked using four algorithms. General rankings identified TATA box binding protein in the first place, followed by transferrin receptor, ribosomal protein large P0, and finally, beta-2-microglobulin, which was revealed as the least stable. Interestingly, universally used GAPDH and ACTB were found to be unsuitable. Our findings strongly suggest a need to evaluate the expression stability of reference gene candidates for each experiment.

Osteochondral lesion of the tibial plafond treated with a retrograde osteochondral autograft: a report of two cases.

BACKGROUND: Osteochondral lesions (OCLs) of the tibial plafond (OLTPs) are rare, and few studies provide treatment recommendations. We describe two cases of an OLTP that were treated with retrograde osteochondral autograft. CASE REPORTS: The first case was a 27-year-old basketball player and the second case was a 38-year-old soccer player. We harvested osteochondral autografts from the nonweight-bearing area of the lateral femoral condyle of the patient's ipsilateral knees. The grafts were reversed and inserted into the bone tunnel reaching the OLTPs starting proximally and moving distally. The first patient was able to play professional basketball 14 months after the procedure and continues to play 5 years and 6 months later. The second patient was able to play recreational soccer 9 months after the procedure and continues to play 4 years later. CONCLUSION: Use of the retrograde osteochondral autograft produced satisfactory results including the return to sports. The retrograde osteochondral autograft can be considered recommendable for treating OLTPs.

Glomus Tumor in the Tarsal Tunnel: A Case Report.

Glomus tumors are painful benign neoplasms. They commonly present in the hand and are mostly solitary lesions. We report a rare case of multiple glomus tumors in the lower leg. Moreover, 1 of the tumors was in the tarsal tunnel. Resection of the tumors resulted in the early diagnosis of glomus tumors and complete symptom relief. Because of its rarity, diagnosing an extradigital glomus tumor is difficult. Recognition of glomus tumors allows for an early diagnosis and resection, and preoperative magnetic resonance imaging helps in the detection of multiple lesions. Before resection, we considered tarsal tunnel syndrome in the differential diagnosis because of the symptoms and location of the tumor. Tarsal tunnel syndrome is a comparatively well-known disease in the foot. When tarsal tunnel syndrome is suspected, a glomus tumor should also be considered in the differential diagnosis.