Hiroki Hachisuka

The cellular origin of cartilage-like tissue after periosteal transplantation of full-thickness articular cartilage defects: An experimental study using transgenic rats expressing green fluorescent protein

Background Periosteal transplantation is commonly used for the treatment of articular cartilage defects. However, the cellular origin of the regenerated tissue after periosteal transplantation has not been well defined. The objective of this study was to investigate the cellular origin of the regenerated tissue after periosteal transplantation. Method Free periosteum was harvested from the tibia of 10-week-old adolescent enhanced green fluorescent protein (GFP-) expressing transgenic Sprague Dawley (SD) rats and was transplanted to full-thickness articular cartilage defects of the patellar groove in normal 10-week-old adolescent SD rats. The periosteum was sutured to the defect with the cambium layer facing the joint cavity. 8 SD rats were killed at 4 weeks and 8 SD rats were killed at 8 weeks after surgery. The repaired tissue was assessed histologically and histochemically. GFP-positive cells derived from the donor periosteum could easily be detected in the repaired tissue by use of a fluorescent microscope. Results At both 4 and 8 weeks after transplantation, the entire area of the defects had been repaired, with the regenerated tissue being well stained histologically with safranin-O. Most cells in the whole area of the regenerated tissue were GFP-positive, indicating that very few of the cells were GFP-negative cells originating from the recipient rats. Interpretation This experiment demonstrates that most cells in regenerated tissue after periosteal transplantation using adolescent animals do not originate from recipient cells but from the periosteal cells of the donor.   ▪

Florid reactive periostitis of the metatarsal bone : A case report

First described by Spjut and Dorfman in 1981,12 florid reactive periostitis (FRP) (also called parosteal fasciitis,6 fasciitis ossificans,3 benign fibro-osseous pseudotumor,4 and pseudomalignant osseous tumor of soft tissue7) is a rare benign juxtacortical soft-tissue lesion. Approximately 60 cases have been reported in the English-language medical literature.11 Usually, FRP involves the proximal and middle phalanges of the hands and, less commonly, the feet. Only one previously reported case involved a metatarsal bone.

Once-weekly teriparatide administration for an Anderson type II odontoid fracture in an elderly patient: A case report

Cervical spine injuries, especially upper cervical, have increased in the elderly [1]. In the elderly, stiffness of the lower cervical spine, caused by degenerative changes and osteopenia, might contribute to upper cervical spine injury, such as odontoid fracture, in response to low energy trauma such as a fall from standing height [2]. Anderson type II odontoid fractures are associated with high rates of mortality in elderly patients regardless of intervention [3]. Teriparatide, for the treatment of osteoporosis, has two types of medications: 1) 20 mg given once daily by self-administration (ForteoR, Eli Lilly and Company, Indianapolis, IN, USA). This medication has been widely used in many countries; 2) 56.5 mg given once weekly, administered by nurse or staff (TeriboneR, Asahi Kasei Pharma, Tokyo, Japan). This once-weeklymedication has been used only in Japan. With intermittent use, teriparatide has an anabolic action on the bone, and the effect of bone turnover markers has been shown to differ between these two medications [4]. Although once-daily injection increases bone formation and bone resorption, once-weekly injection increases bone formation moderately and decreases or maintains bone resorption [4]. The effects of both medications on bone mineral density are similar [4].