Yoshihisa Anraku

The chondrogenic repair response of undifferentiated mesenchymal cells in rat full-thickness articular cartilage defects.

OBJECTIVE The aim of this study is to develop a rat model of full-thickness articular cartilage defects that is suitable for detailed molecular analyses of the regenerative repair of cartilage. MATERIALS AND METHODS The V-shaped full-thickness defects (width: 0.7 mm; depth: 0.8 mm; and length: 4mm) were created in the femoral patellar groove of 6 weeks old male rats using a custom-built twin-blade device. Prior to starting the repair experiments, our device was examined for its accuracy and reliability in generating defects. Then, the time course of the repair response in these cartilage defects was examined using a semi-quantitative histological grading scale. The expression of chondrogenic differentiation markers in the reparative regions was examined with immunohistochemistry and in situ hybridization. RESULTS Our device creates full-thickness articular cartilage defects uniformly. In these defects, undifferentiated mesenchymal cells filled the defect cavities (4 days) and initiated chondrogenic differentiation at the center of the defect (7 days). Cartilage formation was observed in the same region (2 weeks). Finally, hyaline-like articular cartilage and subchondral bone layers were reconstituted in their appropriate locations (4 weeks). CONCLUSIONS We have successfully developed a rat model containing identically sized full-thickness defects of articular cartilage that can undergo chondrogenic repair in a reproducible fashion.

Clinical results of trochanteric fractures treated with the TARGON® proximal femur intramedullary nailing fixation system

The aim of this study was to investigate the outcome of 352 (71 males) patients with trochanteric fractures that were treated with the TARGON® PF nail. The mean age was 83 years. According to the Jensen classification, there were 35 cases in type 1,94 cases in type 2,75 in type 3,63 in type 4 and 85 in type 5. Postoperative all patients were allowed to fully weight bear from the first postoperative day. Clinical and radiological data were collected at regular time intervals. The average waiting time to surgical reconstruction for the 352 cases was 3.5 days (1-7). The mean length of hospital stay was 14 days (5-22). The operative times ranged from 11 to 125 minutes with an average time of 32 minutes. Fifty percent of the patients regained their mobility to their pre-injury level at the final follow up. Out of 310 patients (88%) who were available for radiographie assessment, all fractures united except one case. 300 (85%) of the lag screws were placed in the inferior area in the anteroposterior view and in the central area in the lateral view (IM), which is regarded as the optimal position. The lag screws back-slided between 0 and 19 mms with an average of 6 mm. Sliding distance of the lag screw for over 10 mm was seen in 42 cases (13%). Varus collapse of the femoral head-and-neck greater than 10° was observed in 6 cases. Postoperative complications developed in 6 cases (1.7%), including wound infection in two cases, and secondary fracture at the subtrochanteric region, nonunion, back-out of the guiding sleeve and medial perforation of the lag screw, each in one case. The presented case series indicates that the TARGON® PF system is an effective and safe internal fixation device for trochanteric proximal femoral fractures. Further, prospective comparative evidence regarding the use of this system is needed to analyse and validate the presented clinical impression of our centre.

A reduced linezolid dosage maintains favorable efficacy with minimal hematologic toxicity in a methicillin-resistant Staphylococcus aureus-infected patient with renal insufficiency

Abstract The optimal dosage of linezolid to avoid hematologic toxicity is unknown. We report the case of an 87-y-old woman with renal insufficiency who developed a surgical site infection with refractory methicillin-resistant Staphylococcus aureus. The standard dosage of linezolid (1200 mg daily) was not initially tolerated by the patient due to severe thrombocytopenia, but she was successfully treated when the dose was reduced by half (600 mg daily) based on a population pharmacokinetic–pharmacodynamic model. Appropriate dose adjustments can be made to optimize linezolid therapy especially in cases with preexisting renal dysfunction.

A Case Report of Tuberculosis of the Cervical Spine with the Barré-Liéou Syndrome

Tuberculosis of the cervical spine is uncommon to arise in the whole apine. We report a case of tuberculous cervical spondylitis with Barre-Lieou syndrome.The case was a 61 year old female, who complained of mild muscle weakness and strong dizziness at motion, headache, nausea, so called Barre-Lieou syndrome. MRI showed rim enhancement of the retropharyngeal soft tissue and peridural abscess. We therefore performed the operation of curretage and anterior spinal body fusion by use of autogenous fibula bone, adding the chemotherapy of INH, RFP and SM. She gradually recovered from Barre-Lieou syndrome.The origin of Barre-Lieou syndrome in this case was unsidered the source of the irritation of the vertebral nerve by tuberculous abscess.

Results of Surgical Treatment for Lumbosacral Radiculopathy of Lumbar Spinal Stenosis

This study investigated the operative results of the lumbosacral radiculopathy of lumbar canal stenosis. 24 cases were treated by surgery 9 cases received fenestration, 8 cases also received wide laminectomy, and in addition 7 cases received lumbar segmental fusion by instrumentation. The mean age at the time of surgery was 69.8 years (ragne; 56 to 81 years). The mean duration of follow-up was 23 months (range; 12 to 31 months).The clinical results were evaluated by the JOA score, and the recovery rate was determined by Hirabayashis method, and by the recovery ratio of radiculopathy symptoms, pain and dysesthesia of the lower extremities. The preoperative mean JOA score was 14.5 points, which changed to 20.5 points at the final check, and the mean recovery rate was 42.7%. The recovery ratio of radiculopathy pain shows a tendency to decrease as the number of decompressed intervertebral segments increase.