Atraumatic hemarthrosis caused by a large mediopatellar plica.

Hemarthrosis of the knee has various etiologies and is classified into atraumatic or post-traumatic. Among atraumatic factors, hemarthrosis due to synovial plica is extremely rare. We report a case of atraumatic hemarthrosis caused by the mediopatellar plica. A 21-year-old male truck driver was referred to our hospital, because of swelling and pain of the right knee without history of trauma. Bloody synovial fluid was aspirated by arthrocentesis. However, his symptoms recurred and persisted. The range of motion was normal, but the patient complained of anteromedial knee pain during maximum flexion. Routine biochemical analyses were within normal limits. Plain radiographs were normal. Magnetic resonance imaging (MRI) of the knee showed the hypertrophic mediopatellar plica and an irregular signal of the infrapatellar fat pad. Arthroscopy revealed a voluminous mediopatellar plica trapped between the patella and the medial femoral condyle. It attached to the center of the infrapatellar fat pad, the so-called tongue. When the tourniquet was released, fresh bleeding was observed from the region between the mediopatellar plica and the tongue. Because that region was considered to be the cause of the hemarthrosis, the mediopatellar plica and the tongue were excised. A histologic examination of the tongue showed evidence of bleeding with nonspecific synovitis. After the procedure, the patient was asymptomatic and there were no clinical signs of recurrence.

Fluorovisualization effect of acridine orange on mouse osteosarcoma.

If the localization of musculoskeletal sarcomas could be visualized during surgery, it would be possible to completely resect the tumor with minimum damage to normal tissues and the patients could retain a functional limb. Therefore, we conducted the present study to clarify the usefulness of acridine orange (AO) for fluorovisualization of tumors using a mouse osteosarcoma model. At 2 hours after injection of 10 mg/kg AO to mice inoculated with MOS mouse osteosarcoma cells, fluorovisualization of mouse osteosarcoma reached the maximum level. Even a 1-mm-diameter lesion of pulmonary metastasis was visualized. The results suggested that AO may be useful for specific fluorovisualization of human osteosarcomas during surgery.

Total tumor cell elimination with minimum damage to normal tissues in musculoskeletal sarcomas following photodynamic therapy with acridine orange.

Acridine orange (AO) has unique biological actions enabling tumor visualization (fluorovisualization) and a strong cytocidal effect (photodynamic therapy: AO-PDT) under illumination with blue light. Accordingly, in this study, we attempted to develop a new surgical technique for total tumor cell elimination using these photodynamic reactions with AO in a mouse osteosarcoma model. The results showed that local tumor recurrence was significantly inhibited (23%) in the group treated with curettage under fluorovisualization and AO-PDT, compared to that (80%) in the control group treated with curettage alone under ordinary light. Therefore, we concluded that the combination of curettage under fluorovisualization and AO-PDT may be useful for total tumor cell elimination with minimum damage to normal tissue in musculoskeletal sarcomas.

Photodynamic inactivation with acridine orange on a multidrug-resistant mouse osteosarcoma cell line.

Overcoming multidrug resistance (MDR) is an urgent issue to improve the prognosis of osteosarcoma patients. In this study, we undertook to clarify the effect of photodynamic therapy (PDT) with acridine orange (AO) on the MDR mouse osteosarcoma (MOS / ADR1) cell line, by comparing the outcome with the effect on a chemosensitive osteosarcoma (MOS) cell line. Cultured cells of MOS and MOS / ADR1 cell lines were exposed to AO at various concentrations for various times, followed by long- or short-term (10 or 1 min) illumination with blue light (466.5 nm) for excitation. Living cells were counted by means of the trypan blue exclusion test. The results showed that AO rapidly bound to DNA, RNA and lysosomes of living MOS and MOS / ADR1 cells and also that most tumor cells in both cell lines died rapidly (viability ratio to untreated cells: 1/1000) within 48 h under conditions of continuous or 15-min flash exposure to AO at concentrations above 1.0 microg/ml plus 10-min illumination with blue light. Even after flash exposure to AO at concentrations above 1.0 microg/ml plus 1-min illumination, the viability of MOS/ADR1 cells decreased to a viability ratio of less than 1/ 1000 within 72 h. Based on these results, we concluded that AO with photo-excitation has a strong cytocidal effect, not only on chemosensitive mouse osteosarcoma cells, but also on MDR mouse osteosarcoma cells. These results suggested that photodynamic therapy with AO may be a new approach to treating MDR human osteosarcomas.

A new arthroscopic method for reconstructing the anterior and posterior cruciate ligaments using a single-incision technique: simultaneous grafting of the autogenous semitendinosus and patellar tendons.

We established a simultaneous reconstruction method for ruptured anterior and posterior cruciate ligaments (ACL, PCL) using a single-incision technique. Residual PCL was used to determine the position of bone tunnel for ACL reconstruction. The bone tunnel position on the tibia for PCL reconstruction was arthroscopically confirmed by conducting through debridement from the posteromedial portal. Reconstruction substitutes were patellar-tendon bone-tendon-bone for ACL, and semitendinosus tendon for PCL. In the fixation procedure, the PCL substitute was fixed using the Endobutton (Smith & Nephew, Andover, MA) and a ceramic button, and the ACL substitute was fixed with an interference screw. During the surgery, radiographic monitoring and the PCL guide system were not required.

A survey of filling methods, intracanal medications, and instrument breakage.

The present survey was conducted to obtain answers to some basic questions regarding the use of intracanal medications, root canal filling methods, and the intracanal breakage of instruments. A letter was sent to 300 endodontists listed in the 1995-1996 membership roster of the American Association of Endodontists. Eighty-five replies were received. Calcium hydroxide as an intracanal medication was used by 91.7% of the responding endodontists. With regard to the root canal filling technique, 52.9% used the lateral condensation method. When intracanal breakage occurred, 95.3% of the respondents informed the patient. The results of this survey provide useful information for the education of undergraduate dental students.

Successful embolization for uterine hemorrhage in a patient with acute promyelocytic leukemia.

A successful embolization for life-threatening uterine hemorrhage is described in a patient with acute promyelocytic leukemia and disseminated intravascular coagulation. On admission the patient was in the 6th week of gestation with incomplete abortion and uterine hemorrhage. In addition to combination chemotherapy and anticoagulant therapy, dilatation and curettage were also performed. After the operation the uterine hemorrhage was progressively increased in amount and was not responsive to usual measures. Embolization of bilateral uterine arteries using Gelfoam was performed with a dramatic improvement of the hemorrhage.