Subchondral insufficiency fractures of the medial tibial condyle are associated with medial meniscus extrusion: A retrospective observational study.

BACKGROUND: To the best of our knowledge, no prior studies have identified any risk factors for subchondral insufficiency fractures of the medial tibial condyle. This study aimed to explain relationships between subchondral insufficiency fractures of the medial tibial condyle and the meniscus status, lower extremity alignment, or osteoporosis. METHODS: This retrospective study included 325 consecutive patients whose chief complaint is knee joint pain and who had visited one institution between April 2016 and March 2021, of which 70 patients (8 men and 62 women) who had suspected subchondral insufficiency fractures of the medial tibial condyle had undergone magnetic resonance imaging and radiographic examination. These patients were divided into two groups based on the results of their magnetic resonance imaging: the insufficiency fracture group included 46 patients who had subchondral insufficiency fractures of the medial tibial condyle and the nonfracture group included 24 patients without fractures. The meniscus injury and medial meniscus extrusion (MME) were evaluated by using magnetic resonance imaging. The Kellgren-Lawrence grade, the femorotibial angle, and the percent mechanical axis (%MA) were evaluated with the use of knee radiographs. T-scores were also measured by using dual-energy X-ray absorptiometry with a bone densitometer. RESULTS: MME were significantly larger and the %MA was significantly smaller in the insufficiency fracture group than that in the nonfracture group. The prevalence of medial meniscus injuries and pathological MME were higher in the insufficiency fracture group than those in the nonfracture group. The prevalence of varus knee and osteoporosis did not vary remarkably different between the two groups. CONCLUSION: The patients who had insufficiency fractures of the medial tibial condyle tended to have medial meniscus extrusion.

Comparison of the Efficacy of Two High-Molecular-Weight Hyaluronic Acid Products for Patients With Knee Osteoarthritis.

In Japan, hyaluronic acid (HA) is often used to treat patients with relatively mild knee osteoarthritis (OA). The use of HA in and the physique and lifestyle of the Japanese population differ from those of other populations. Therefore, clinical reports of HA from around the world must be interpreted with caution for application in Japan. We compared the clinical efficacy of two HA products, with average molecular weights of 900,000 (HA90) and 1.9 million (HA190), for Japanese patients with knee OA. There were 49 patients and 54 knees (27 patients received both HA90 and HA190 injections). We used a disease-specific/patient standing-type knee OA function evaluation scale that was developed earlier and later improved considering the uniqueness of the Japanese lifestyle. The assigned HA product was injected into the joints of patients with knee OA with Kellgren-Lawrence classification system grades I to III once a week, for 5 consecutive weeks. Effects were subjectively self-evaluated using the Japanese Knee Osteoarthritis Measure (JKOM) and a visual analog scale. The average age of the patients was 65.4 years (range, 42-88 years). Both HA products alleviated walking pain and improved JKOM scores, and symptoms continued to improve with continued injections for 6 months. The continued administration of HA90 improved general activity more than that of HA190. In contrast, HA190 improved initial pain more, but its continued administration did not contribute to improving general activity. These results suggest that it may be effective to use different HA products depending on the symptoms and conditions of patients with knee OA. [Orthopedics. 2022;45(1):13-18.].

[A Case of Fanconi Syndrome Induced by Zoledronic Acid in a Metastatic Colorectal Cancer Patient].

A 60s-year-old woman with metastatic colorectal cancer was treated using mFOLFOX6 plus bevacizumab. Zoledronic acid was also administered owing to the presence of bone metastasis. The patient was admitted to our hospital with progressive hypokalemia, hypocalcemia, hypophosphatemia, and proximal renal tubular dysfunction. A diagnosis of Fanconi syndrome was made, and was believed to be induced by zoledronic acid treatment. This treatment was discontinued, and the patient's renal tubular function recovered. Denosumab was subsequently administered to treat the bone metastasis, and no renal tubular dysfunction occurred. It was possible to continue chemotherapy, and a complete response was obtained. Fanconi syndrome induced by zoledronic acid is rare, but it may hinder chemotherapy. Therefore, monitoring renal tubular function is recommended during therapy with zoledronic acid.

A case of idiopathic encapsulating peritoneal sclerosis with intractable ileus successfully treated by surgery and steroid therapy.

Encapsulating peritoneal sclerosis (EPS) occurring without a history of peritoneal dialysis is rare. We report on a patient with idiopathic EPS following intractable ileus who was successfully treated by surgery and postoperative steroid therapy without any sign of recurrence. A 67-year-old woman was referred to our department for further treatment of intractable ileus. Abdominal CT scanning revealed wall thickening of the proximal jejunum. Double-balloon enteroscopy disclosed stenosis of the jejunum at 20 cm anally from the Treitz ligament, although the intestinal mucosa appeared normal without specific biopsy findings. In addition, FDG-PET showed no abnormal accumulation, thus discounting a malignant lesion. Since conservative therapy failed to improve the ileus, we performed an operation on her in order to release the ileus and make a histological diagnosis. Surgical findings included a whitish thickening of the serosa extending to the intestine and the whole mesentery. Accordingly, we made a diagnosis of idiopathic encapsulating peritoneal sclerosis because of her negative history of peritoneal dialysis, laparotomy or peritonitis, in addition to the above-noted findings. Postoperative oral administration of steroid has suppressed EPS recurrence. In patients with intractable ileus, EPS should be added to the list of differential diagnoses, even if they have not undergone peritoneal dialysis.

[A case of colon cancer resembling submucosal tumor with ossification].

A 62-year-old man was admitted to our hospital because of elevated serum CEA and CA19-9. Colonoscopy disclosed a submucosal tumor (SMT) in the ascending colon. CT showed a tumor with partial calcification, 40 x 30 mm in size. FDG-PET showed no abnormal uptake in the tumor. During a follow-up three months later, colonoscopy showed an ulcer on the upper surface of the SMT, and pathological findings of the biopsy specimen disclosed mucinous adenocarcinoma. Right hemicolectomy was performed. Pathological findings of the resected specimen showed mucinous adenocarcinoma invading the subserosa with heterotopic ossification of the same site as the calcification on CT.

Novel maglev pump with a combined magnetic bearing.

The newly developed pump is a magnetically levitated centrifugal blood pump in which active and passive magnetic bearings are integrated to construct a durable ventricular assist device. The developed maglev centrifugal pump consists of an active magnetic bearing, a passive magnetic bearing, a levitated impeller, and a motor stator. The impeller is set between the active magnetic bearing and the motor stator. The active magnetic bearing uses four electromagnets to control the tilt and the axial position of the impeller. The radial movement of the levitated impeller is restricted with the passive stability dependent upon the top stator and the passive permanent magnetic bearing to reduce the energy consumption and the control system complexity. The top stator was designed based upon a magnetic field analysis to develop the maglev pump with sufficient passive stability in the radial direction. By implementing this analysis design, the oscillating amplitude of the impeller in the radial direction was cut in half when compared with the simple shape stator. This study concluded that the newly developed maglev centrifugal pump displayed excellent levitation performance and sufficient pump performance as a ventricular assist device.

Magnetically suspended centrifugal blood pump with a self bearing motor.

A magnetically suspended centrifugal blood pump with a self bearing motor has been developed for long-term ventricular assistance. A rotor of the self bearing motor is actively suspended and rotated by an electromagnetic field without mechanical bearings. Radial position of the rotor is controlled actively, and axial position of the rotor is passively stable within the thin rotor structure. An open impeller and a semiopened impeller were examined to determine the best impeller structure. The outer diameter and height of the impeller are 63 and 34 mm, respectively. Both the impellers indicated similar pump performance. Single volute and double volute structures were also tested to confirm the performance of the double volute. Power consumption for levitation and radial displacement of the impeller with a rotational speed of 1,500 rpm were 0.7 W and 0.04 mm in the double volute, while those in the single volute were 1.3 W and 0.07 mm, respectively. The stator of the self bearing motor was redesigned to avoid magnetic saturation and improve motor performance. Maximum flow rate and pressure head were 9 L/min and 250 mm Hg, respectively. The developed magnetically suspended centrifugal blood pump is a candidate for an implantable left ventricular assist device.

Expression of the anaphylatoxin receptor C5aR (CD88) by human articular chondrocytes.

Although the complement system is implicated in the inflammatory process in arthritic diseases, a direct interaction between chondrocytes and complement has not been demonstrated. In this study, we investigated expression of the C5a receptor (C5aR) on chondrocytes of cartilage from patients with rheumatoid arthritis (RA), osteoarthritis (OA), and bone fracture as normal controls by reverse transcriptase polymerase chain reaction (RT-PCR), flow cytometry, and immunohistochemistry. The RT-PCR detected mRNA for C5aR in most or all of the tested samples (73% in OA, 100% in RA, 89% in normal). The FACS analysis revealed different expression ratios between individuals varying from 0.7% to 77.1%; however, expression ratios of C5aR were significantly higher in RA than in controls (26.0% in RA, 9.0% in OA, 6.9% in normal). The expression of C5aR was upregulated significantly by addition of IL-1beta in RA and normal samples but not in OA. In addition, the C5aR-positive chondrocytes were confirmed by immunohistochemistry. In conclusion, expression of C5aR and the effect of IL-1beta on the expression were different between RA and OA. The C5aR may contribute to chondrocyte metabolism and the pathogenesis of arthritis differently between in RA and OA.