Computed tomography angiography and magnetic resonance imaging performance of acute segmental single compartment syndrome following an Achilles tendon repair: A case report and literature review.

Acute compartment syndrome of the lower extremity is a serious postinjury complication that requires emergency treatment. Early diagnosis is of paramount importance for a good outcome. Four muscle compartments in the calf (anterior, lateral, deep posterior, and superficial posterior) may be individually or collectively affected. Acute segmental single-compartment syndrome is an extremely rare condition characterized by high pressure in a single compartment space with threatening of the segmental tissue viability. In this case report, we describe a young man with Achilles tendon rupture who complained of postoperative pain in the anterior tibial region. Emergent computed tomography angiography and magnetic resonance imaging revealed local muscle edema. Segmental anterior compartment syndrome was diagnosed and fasciotomy was performed.

Gambogic acid inhibits invasion of osteosarcoma via upregulation of TIMP-1.

Gambogic acid (GA), the natural product, has been demonstrated to be a promising chemotherapeutic drug for osteosarcoma (OS) due to its ability to induce apoptosis and cell cycle arrest. To date, no studies have examined the role of GA in metastatic bone disease. Matrix metalloproteinases (MMPs) play critical roles in invasion and metastasis, and the tissue inhibitors of metalloproteinase (TIMP) family regulates the activity of multifunctional metalloproteinases. In this study, we investigated the gene expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in OS cell lines treated by the GA. The expression of MMP-9 and TIMP-1 were studied by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. In vitro invasion of OS cell lines (Saos-2, MG-63) were investigated by the Matrigel invasion assay. Mean MMP-9 protein and mRNA expression was significantly suppressed; in addition, mean TIMP-1 protein mRNA expression were upregulated by increasing GA concentrations. GA reduced the invasiveness of OS cell lines dose-dependently. Furthermore, specific inhibition of TIMP-1 secretion with siRNA against TIMP-1 significantly reduced the effect of GA on OS cell lines. Overall, our findings suggest that GA reduces the invasive potential of OS cells via attenuation of MMP-9 and upregulation of TIMP-1. Moreover, TIMP-1 played an important role in the reduction of invasive potential of the OS cells which were treated by GA.

Pure alumina bearings with cementless stems versus sandwich bearings with cemented stems in total hip arthroplasty.

BACKGROUND: Ceramic bearing surfaces have been introduced to prevent osteolysis after total hip arthroplasty (THA), but little is known about the difference in clinical and radiological results between pure alumina and sandwich alumina bearings. The purpose of this study was to analyze the results obtained with third-generation alumina-on-alumina THA with two different designs both in liner and femoral stem fixation after a minimum follow-up of 4.2 years. METHODS: The results of 195 primary alumina-on-alumina THAs in 167 patients were evaluated. The procedures were performed between January 1998 and October 2006. Three patients died and 11 patients were lost to follow-up, leaving a total of 153 patients (181 hips) available for study. In the 88 group A patients, 107 hips were implanted using pure alumina bearings with cementless femoral stems. These patients were followed for (6.84 ± 1.49) years. In the 65 group B patients, 74 hips were implanted using sandwich alumina ceramic bearings with cemented femoral stems. These patients had a follow-up period of (7.73 ± 1.60) years. Patients in both groups were evaluated clinically and radiographically. RESULTS: One ceramic liner fracture occurred in group A and five took place in group B (P < 0.05), four of them revised for liner fracture. In each group, one acetabular shell migration happened without liner breakage and two hips developed deep infections, and all these six hips received revisions. Nine femoral components loosened in group B, with seven undergoing revisions. Kaplan-Meier survivorship at 5 years for revision of any component for any reason in group A was 96.26% compared to 90.54% in group B (P < 0.05). Better function was determined in group A (average Harris hip scores: 92.13 ± 2.85) than in group B (average Harris hip scores: 86.03 ± 4.21) and the difference was significant (P < 0.05). Squeaking was not recorded in either group. CONCLUSIONS: The sandwich design of the acetabular bearings can not reduce the migration rate in ceramic bearings but increase the liner fracture rate compared to pure ceramic liners. The high loosening rate in fluted and taped designed cemented stems with sandwich liners warrant caution to their use.

Risedronate inhibits human osteosarcoma cell invasion.

BACKGROUND: Osteosarcoma is a highly malignant bone tumor and is the most commonly encountered malignant bone tumor in children and adolescents. Furthermore, significant numbers of patients eventually develop pulmonary metastases and succumb to the disease even after conventional multi-agent chemotherapy and surgical excision. Several solid tumors display enhanced expression of matrix metalloproteinases (MMPs), and recently clinical trials have been initiated on MMP-inhibitors. On the other hand, bisphosphonates (BPs), which have a profound effect on bone resorption, are widely used to treat osteoclast-mediated bone diseases. BPs are also known to inhibit tumor growths and metastases in some tumors such as breast cancer, renal cell carcinoma, and prostate cancer. METHODS: Two osteosarcoma cell lines (SaOS-2 and U2OS) were treated with risedronate (0, 0.1, 1, 10 microM) for 48 hours. Cell viabilities were determined using MTT assay, the mRNA levels of MMP-2 and MMP-9 were analyzed by reverse-transcription polymerase chain reaction, the amount of MMP-2 and MMP-9 protein were analyzed by Westernblot, the activities of MMP-2 and MMP-9 were observed by Gelatin zymography, and Matrigel invasion assays were used to investigate the invasive potential of osteosarcoma cell lines before and after risedronate treatment. RESULTS: The invasiveness of osteosarcoma cell lines (SaOS-2, U2OS) were reduced in a dose dependent manner follow 48 hour treatment of up to 10 microM of the risedronate at which concentration no cytotoxicity occurred. Furthermore, the gelatinolytic activities and protein and mRNA levels of MMP-2 and MMP-9 were also suppressed by increasing risedronate concentrations. CONCLUSION: Given that MMP-2 and MMP-9 are instrumental in tumor cell invasion, our results suggest the risedronate could reduce osteosarcoma cell invasion.

Regeneration of the fibula using a periosteum-preserving technique in children.

Bone grafting is a commonly used surgical procedure, particularly in reconstructive orthopedic surgery. Bone grafts may be used to fill skeletal defects created by trauma, infection, tumors, or congenital malformation. Fibular graft is an ideal option and is widely used to treat massive segmental defects; however, it leads to various complications, especially in children. This article describes our experience with donor site bone grafts using a periosteum-preserving technique with respect to minimizing donor site complications and performing effective reconstruction of bone defects in children. Seventeen patients who were followed after fibula resection and bone grafting in the donor site using a periosteum-preserving technique were evaluated radiologically and clinically. The patients were divided into 2 groups: 1 group was filled with cancellous allograft (n=9), and the other group was filled with calcium sulfate (n=8) in the donor site. Mean patient age was 8.4 years (range, 2-13 years), and mean follow-up was 31 months (range, 7-65 months). Complete regeneration of the donor sites occurred in all patients; mean time to regeneration at donor sites was 12 weeks (range, 4-21 weeks). There were no significant donor site complications intraoperatively or immediately postoperatively. The average regeneration index was 0.5 (range, 0.2-1.1), and it was found to increase with age (r=0.75, P<.001), indicating that younger patients had faster regeneration. The periosteum-preserving technique was found to lead to the reconstruction of bone defects effectively in children with minimal donor site complications.