The objective of this study is to examine the differential expression of mast cell tryptase and its receptor, protease-activated receptor-2 (PAR-2), in the synovium and synovial fluid of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Biochemical and immunohistochemical analyses were performed to determine whether the trypsin-like protease in the synovium is identical to mast cell tryptase. The effects of mast cell tryptase on the proliferation of synovial fibroblast-like cells (SFCs) and the release of IL-8 thereof were evaluated by the [3H]-thymidine incorporation and ELISA, respectively. The trypsin-like protease in the synovium of RA patients was identical to human mast cell tryptase, which was composed of two subunits: 33 and 34 kDa. The 33- and 34-kDa proteins are different glycosylated forms of the 31-kDa protein, which was unglycosylated. Mast cell tryptase activity in RA synovial fluid was significantly higher than that in OA synovial fluid, while their activities and expression in the synovium were similar. Expression of PAR-2 mRNA in the synovium was higher in RA than in OA. Mast cell tryptase containing the unglycosylated 31-kDa subunit was the predominant form in synovial fluid. RA patients had higher amounts of this subunit in their synovial fluid than OA patients. Mast cell tryptase and PAR-2 activating peptide stimulated the proliferation of SFCs and release of IL-8 from these cells. Mast cell tryptase secretion into RA synovial fluid is higher than OA synovial fluid. Mast cell tryptase in synovial fluid stimulates the proliferation of SFCs and the release of pro-inflammatory cytokines via PAR-2, which may contribute to exacerbation of synovitis in RA.

: The pedicle screw (PS) system is widely used for spinal reconstruction. Recently, screw insertion using the cortical bone trajectory (CBT) technique has been reported to provide increased holding strength of the vertebra, even in an osteoporotic spine. CBT is also beneficial due to its low invasiveness. We have been performing hybrid reconstruction with CBT at the cranial level and PS at the caudal level based on the concept of minimal invasiveness. We applied this hybrid technique to 6 cases of degenerative spondylolisthesis. Surgery was completed with a small skin incision of around 5-6 cm, which is shorter than that of the conventional PS procedure. The mean percent slippage before surgery was 19.8% %, and this was reduced to 3.9% % after surgery and almost maintained 3 months after surgery. Furthermore, no major surgical complications were observed. Here, we introduce the minimally invasive hybrid technique of CBT-PS. Surgeons should be aware of the procedure as an option for minimally invasive lumbar spine reconstructive surgery.

With long fusions to the sacrum in the treatment of spinal deformity, the use of bilateral S1 screws alone may allow for screw loosening/pullout and/or L5-S1 cage/graft collapse/subsidence. Adding bilateral iliac screws and an anterior structural cage/graft at L5-S1 will protect the S1 screws, but may still allow L5-S1 rod breakage/dislodgement because of lumbosacral pseudarthrosis. Revision surgery in these patients remains a challenge.

No abstract

Adult spinal deformity patients with preoperative hypolordosis who were positioned prone during reconstructive surgery had an enhanced lumbar lordosis via positioning alone compared with theirpreoperative upright radiographs. Conversely, those with substantial preoperative lordosis remained unchanged with intraoperative prone positioning. This knowledge will help in the surgical planning of adult spinal deformity reconstructive surgery to optimize sagittal alignment and balance.

Between 1995 and 1999, 12 patients aged 65 years or more (mean 70.2) with lumbar disc herniation, underwent partial laminectomy and nucleotomy. The results were compared with those of 25 younger patients aged between 20 and 40 years (mean 30.1), who underwent the same surgical procedure. The Japanese Orthopedic Association (JOA) score was used to assess the clinical outcome. The minimum follow-up was 12 months. The pre- and post-operative total JOA scores and the rate of improvement of the JOA score were not significantly different between the elderly (11.1, 24.3 points, and 74.1%), and the younger group (11.6, 26.4 points and 84.5%). The results of this study indicate that the outcome of lumbar discectomy in elderly patients is as good as in younger patients.

The functional and anatomical results of distal end of radius fractures with severe displacement in 22 elderly patients are reviewed in this retrospective study. The mean age of the patients was 69.4 years (range, 60-88 years) and the mean follow-up period was 24 months (range, 12-53 months). According to the sum of demerit points (Saito, 1983), the latest follow-up functional end results were excellent in 64% of fractures and good in 36%. As for the anatomical results at follow-up, the average radial tilt was 20.7 degrees, ulnar variance was 4.0 mm, and palmar tilt was -2.7 degrees respectively. Though most of the patients had satisfactory outcome and the functional results did not correlate with the radiographic evidence of minor deformities, the functional results of the patients with radial shortening of 6 mm or over were poor. Furthermore, the grip power was the most significant factor related to subjective evaluation and did not improve significantly in patients with the non-dominant hand injured.

The pseudarthrosis rate in the BMP group compares favorably to pseudarthrosis rate in ICBG group, suggesting that the use of rhBMP-2 without iliac harvesting leads to a competitive fusion rate in long adult spinal deformity surgery, while avoiding ICBG harvest site morbidity.