Objective To investigate the effect of glucocorticoid on the expression levels of osteoprotegerin (OPG)/receptor activator of nuclear factor kappa B ligand (RANKL)-matrix metalloproteinases (MMP)/tissue inhibitor of matrix metalloproteinase (TIMP) system in bone tissues of femoral head of rats, and to discuss its interrelated action mechanism in glucocorticoid-induced avascular necrosis of femoral head (ANFH). Methods Forty adult Sprague Dawley rats, weighing 250-300 g, half males and half females, were randomly divided into 4 groups: high dose glucocorticoid group (HD, n=10), medium dose glucocorticoid group (MD, n=10), low dose glucocorticoid group (LD, n=10), and control group (n=10). The rats in HD group, MD group, and LD group were intramuscularly injected with 25.0, 12.5, and 7.0 mg/kg of prednisolone respectively, and the rats in the control group were injected with physiological saline. After 4 weeks intervention, the osteonecrosis of left femoral heads was observed by HE staining, total RNA was extracted from the right femoral head bone tissue and the mRNA expression levels of OPG, RANKL, MMP-2, MMP-9, TIMP-1, and TIMP-2 were detected by RT-PCR. Results After injection of prednisolone, 4 rats of HD group and 1 rat of MD group died of systemic failure caused by the decreased food and weight culminating in cachexia. HE staining showed that the integrity of bone trabecula and osteon was destroyed at different levels, discontinuous bone chips formed, and osteocytes were replaced by granulation tissue in some lacunae in HD, MD, and LD groups; the integrated osteon was observed, the lamellar structure formed concentric circles around the blood vessel and osteocytes were seen in the lacunae in the control group. The necrosis rates of femoral head were 83.3% (5/6), 66.7% (6/9), 30.0% (3/10), and 0 (0/10) in HD, MD, LD, and control groups. The results of RT-PCR showed: the mRNA expression levels of the OPG, TIMP-1, TIMP-2 in HD, MD, and LD groups were lower than those in the control group, showing significant differences (P lt; 0.05) and there was negative correlation with the hormone dosage. The difference in OPG expression was significant between the hormone groups (P lt; 0.05); the differences in the TIMP-1 and TIMP-2 expressions were not significant between the LD group and MD group (P gt; 0.05), but there were significant differences when compared with HD group (P lt; 0.05). The RANKL, MMP-2, and MMP-9 mRNA expression levels in HD, MD, and LD groups were higher than those in the control group and there was a positive correlation with the hormone dosage, showing significant differences when compared MD and HD groups with control group (P lt; 0.05); there was no significant difference in RANKL expression between HD group and MD group (P gt; 0.05), but there was significant difference when compared HD and MD groups with LD group (P gt; 0.05); no significant difference was observed in the MMP-2 and MMP-9 expression between MD group and LD group (P gt; 0.05), but the differences were significant when compared with HD group (P lt; 0.05). Conclusion Glucocorticoid-induced ANFH may be related to the expression levels of OPG/RANKL-MMP/TIMP mRNA regulated by glucocorticoid.
Objective To investigate the effectiveness of minimally invasive plate fixation in treatment of unstable pelvic fractures. Methods Between May 2006 and December 2009, 21 patients with unstable pelvic fractures were treated. There were 13 males and 8 females with an average age of 39 years (range, 21-66 years). The causes of injury included traffic accident in 9 cases, falling from height in 6 cases, and heavy pound injury in 6 cases. The time from injury to hospitalization was 1 to 4 hours with an average of 2.8 hours. According to Tile’s classification, there were 12 cases of type B and 9 cases of type C. After admission, bone traction and exo fixation were performed, and minimally invasive plate fixation was given at 5-24 days after injury. Results All incisions healed by first intention, and no complications of nerve and vessel injuries occurred. According to the reduction criteria of Matta radiography, anatomic reduction was achieved in 16 cases, satisfactory reduction in 4 cases, and fair reduction in 1 case. All patients were followed up 12 months. The X-ray films showed all fractures healed at 2-4 months (mean, 2.6 months). According to Majeed clinical evaluation, the results were excellent in 12 cases, good in 7 cases, and fair in 2 cases. Conclusion Minimally invasive plate fixation can provide effective fixation, reconstruct pelvic ring, and reduce perioperative complications in the treatment of unstable pelvic fractures.
Objective To evaluate the effectiveness of limited open reduction and double plates internal fixation in the treatment of Vancouver type B1 periprosthetic femoral fracture after hip arthroplasty. Methods A retrospective analysis was made on the clinical data of 12 patients with Vancouver type B1 periprosthetic femoral fracture after hip arthroplasty between May 2007 and October 2012, who underwent limited open reduction and double plates internal fixation. Of 12 patients, 4 were male and 8 were female, aged 76-85 years (mean, 81.6 years); the left side was involved in 5 patients and the right side in 7 patients. The cement prosthesis was used in 3 cases and cementless prosthesis in 9 cases; double acting head of hip arthroplasty was performed in 4 cases and total hip arthroplasty in 8 cases. The median time from first hip arthroplasty to re-fracture was 13 months (range, 5 months-5 years). The causes of injury were traffic accident in 2 cases and falling in 10 cases. Combined fractures included contralateral tibial and fibular fractures and ipsilateral distal humeral fracture (1 case), ipsilateral proximal humeral fracture (2 cases), ipsilateral distal radial fracture (1 case), and rib fracture (1 case). The time from injury to operation was 5.6 days on average (range, 3-10 days). Results The incisions all healed by first intention, and no infection or deep venous thrombosis of lower extremity occurred. Twelve cases were followed up 6-24 months (mean, 13.3 months). One female patient died of acute myocardial infarction at 16 months after operation. All the fractures were healed, with X-ray healing time of 12.5 weeks on average (range, 10-16 weeks). The time of full weight bearing was 13 weeks on average (range, 10-18 weeks). Ten cases could walk freely after operation, and 2 cases could walk by the aid of walking aid appliance. At last follow-up, the Harris score of hip function was 87.3 on average (range, 75-93). Conclusion The method of limited open reduction and double plates internal fixation for Vancouver type B1 periprosthetic femoral fracture after hip arthroplasty is effective in maintaining stability, protecting blood supply, promoting fracture healing, and doing functional exercise early. The long-term effectiveness needs further observation.