Pyoderma gangrenosum with wrist joint destruction: case report.

Pyoderma gangrenosum (PG) is a rare, noninfectious, neurotrophic dermatosis. We observed a case of PG mimicking cutaneous and osteoarticular infections that presented with a prolonged ulcer on the forearm, severe wrist pain, anemia, substantial local and systemic inflammation as evaluated by serum laboratory data, and carpal osteolysis. Although PG rarely damages joints, the ulcer extended to the joint and destroyed the osteochondral tissues. Advanced ulcerative colitis, which is a most common comorbidity of PG, proved to be an underlying disease. Antibiotic and surgical treatment did not heal the ulcer, which was successfully treated with corticosteroids. This intractable ulcer is often misdiagnosed. Hence when a patient presents with an enlarged, painful, unusual skin lesion, PG should always be considered.

Internal fixation with the low profile plate system compared with Kirschner wire fixation: clinical results of treatment for metacarpal and phalangeal fractures.

A total of 71 patients with 78 metacarpal or phalangeal fractures were treated using one of two different methods of fixation. Thirty-nine fingers were treated using a low profile plate and screw system (LPP group), whereas 39 fingers were treated using Kirschner wire (K-wire group). In the LPP group, three cases of screw breakage were recorded. The LPP group required use of a splint for 0.9 weeks, significantly less than the 4.4 weeks of the K-wire group. The mean of 2.6 +/- 1.6 months for the time to union in the LPP group was significantly greater than the 1.6 +/- 0.6 months in the K-wire group. There were no instances of non-union in both groups, but one delayed union was observed in the LPP group. Total active flexion was 235 degrees and 243 degrees in the LPP and the K-wire groups, respectively. Total extension loss was 12 degrees and 9 degrees in the LPP and the K-wire groups, respectively. Although use of either method resulted in a good range of motion, LPP fixation required a much shorter time with a splint. However, because of the possibility of screw breakage, we have to exercise caution with post-operative treatment.

Bone formation following OP-1 implantation is improved by addition of autogenous bone marrow cells in a canine femur defect model.

Osteogenic Protein-1 (OP-1, BMP-7) acts locally on connective tissue progenitors (CTPs) to induce bone formation. The response to OP-1 and similar agents is potentially limited by the number of local CTPs. This study tested the hypothesis that supplementing local CTPs using autogenous bone marrow will enhance bone formation at an OP-1 implant. Four 1.0-cm diameter unicortical cylindrical defects in the left proximal femur were grafted in each of seven dogs. Radial ingrowth of new bone formation was assessed at 4 weeks using micro CT. The OP-1 (3.5 mg rhOP-1 in 1 g bovine collagen I matrix) was implanted in each site combined with either clotted blood or aspirated bone marrow (BM). Bone formation was increased in the group augmented with transplanted marrow. These data suggest that increasing the local population of cells and CTPs using aspirated bone marrow can enhance the performance of OP-1, but may not eliminate the effects of site variation on the response to OP-1 and similar agents. The canine multiple femoral defect model defined in this study is well suited to quantitatively evaluate strategies for augmenting bone repair using local cell targeting and cell transplantation strategies.

Effects of vibration and hyaluronic acid on activation of three-dimensional cultured chondrocytes.

OBJECTIVE: To investigate the effects of vibration (Vib) and hyaluronic acid (HA) on 3-dimensional cultured cartilage. METHODS: Chondrocytes were obtained from metatarsophalangeal joints of freshly killed 6-month-old pigs. Twenty-four-well plates containing type I collagen sponge disks were used to culture samples. The frequency and the amplitude of the vibration of the well plate were 100 Hz and 0.5 nm, respectively. We produced 3-dimensional cartilage tissue using HA and vibration with collagen sponge as a carrier. Four different culture conditions were examined: a control HA-Vib- group, an HA-Vib+ group, an HA+Vib- group, and an HA+Vib+ group. Each group was cultured for 2 weeks. After culture days 3, 7, 10, and 14 (every 3.5 days), the levels of chondroitin 4-sulfate (C4S) and chondroitin 6-sulfate (C6S) isomers synthesized in each culture medium were measured. Histologic analysis, immunohistochemical analysis, and electron microscopic examination were performed. RESULTS: Mean C4S and C6S synthesis had increased rapidly after 7 days of culture and continued to increase thereafter. There were significant differences among the 4 groups (P < 0.01). Synthesis of both C4S and C6S was most abundant in the HA+Vib+ group and the lowest in the HA-Vib- group. After 1 and 2 weeks of culture, the chondrocytes had formed stratified structures on the collagen sponges in all groups, although the thickest structure was observed in the HA+Vib+ group and the thinnest in the HA-Vib- group. Under immunofluorescence, the HA+Vib+ group exhibited the strongest chromatic features. Under electron microscopy, the chondrocytes in the HA+Vib+ group exhibited many long and slender prominences on their surface, and extracellular substance could be observed associated with the cells. CONCLUSION: Our results indicate that the combination of vibration and HA activates the production of proteoglycan in 3-dimensional cultured chondrocytes and stimulates MAPK and beta-catenin. This suggests that some mechanoreceptors for vibration exist on the plasma membrane of chondrocytes and activate the intracellular signal transduction system.