Objective Aminoguanidine (AG) can reduce brain edema and increase the recovery of neuron functions in surgical brain injury and stroke. To investigate the effect of AG on spinal cord injury (SCI) in rats and its mechanism. Methods A total of 150 adult male Sprague Dawley rats (weighing, 230-255 g) were divided into control group (group A, 25 rats without treatment), the sham-operated group (group B, 25 rats undergoing laminectomy), SCI group (group C, 25 SCI rats with injection of 5%DMSO), SCI + AG groups (groups D, E, and F, 25 SCI rats and AG injection of 75, 150, and 300 mg/kg, respectively). The optimal dosage of AG was screened by dry-wet weight method with the percentage of water content at 0, 12, 24, and 48 hours after injury. The blood-spinal cord barriar permeability was further detected by Evans blue (EB) method, aquaporins 4 (AQP4) mRNA expression by RT-PCR, AQP4 protein expression by immunohistochemistry and Western blot. Results AG injection at dosage of 150 mg/kg can significantly reduce edema of spinal cords at 12, 24, and 48 hours after SCI (P lt; 0.05), so 150 mg/kg was the optimal dosage. The EB content in group E was significantly lower than that in group C at 12, 24, and 48 hours after SCI, and the permeability of blood-spinal cord barrier was significantly decreased compared with group C (P lt; 0.05). The AQP4 mRNA expressions in groups B and E were significantly lower than that in group C at 12, 24, and 48 hours after SCI (P lt; 0.05). AQP4 protein expressions in groups B and E were significantly lower than that in group C at 24 and 48 hours after SCI (P lt; 0.05) by Western blot. Immunohistochemical staining revealed that AQP4 protein expression in group C was significantly higher than that in groups B and E (P lt; 0.05) at 48 hours after SCI, but no significant difference was found between group B and group E (P gt; 0.05). Conclusion AG injection at dosage of 150 mg/kg can induce spinal cord edema and injury in rats, which could be correlated with the down-regulation of AQP4 expression.
ObjectiveTo evaluate short-term effectiveness of revision total knee arthroplasty (TKA) with porous-coated metaphyseal Sleeve and MBT implant.MethodsA clinical data of 23 patients (24 knees) who underwent revision TKA by using porous-coated metaphyseal Sleeve combined with MBT implant between March 2015 and April 2017 was retrospectively analyzed. There were 8 males (8 knees) and 15 females (16 knees). The age ranged from 48 to 85 years (mean, 65.4 years). The cause of revision TKA included infection in 14 knees, aseptic loosening in 8 knees, instability in 1 knee, and stiff knee in 1 knee. Bone defects were classified according to the Anderson Orthopaedic Research Institute (AORI) bone defect classification. The femoral defect was rated as type ⅡA in 5 knees, type ⅡB in 17 knees, and type Ⅲ in 2 knees; the tibial defect was rated as type ⅡA in 2 knees, type ⅡB in 20 knees, and type Ⅲ in 2 knees. The mean time between primary TKA and revision TKA was 30.6 months (range, 6-86 months). The preoperative range of motion (ROM) was (56.0±24.9)°. The preoperative Hospital for Special Surgery (HSS) total score was 41.9±14.2; and the pain and function scores were 8.5±5.2 and 33.4±13.5, respectively.ResultsAll patients were followed up 12-39 months (mean, 25.6 months). The mean operation time was 2.2 hours (range, 1.6-2.9 hours). The mean intraoperative blood loss was 580 mL (range, 400-1 000 mL). There were 2 knees (8.3%) of intraoperative fracture associated with Sleeve insertion and 1 knee (4.2%) of acute postoperative infection at 25 days after revision TKA. All incisions healed by first intention. No deep venous thrombosis of lower extremity occurred. X-ray film showed that all implants were stable. At last follow-up, slight discomfort after exercise occurred in 4 knees (16.7%); end-of-stem pain in the tibia occurred in 1 knee (4.2%). The ROM was (114.6±5.1)°, which had significant improvement compared with the preoperative result (t=11.698, P=0.000). The HSS total score (89.0±10.9), pain score (26.9±6.6), and function score (62.1±5.8) also had significant improvement compared with the preoperative results (t=15.616, P=0.000; t=12.522, P=0.000; t=10.076, P=0.000).ConclusionThe porous-coated metaphyseal Sleeve combined with MBT implant in revision TKA has a significant improvement in short-term effectiveness and no signs of implant loosening.