ABSTRACT
Introduction: The theory that usingmobile bearing (MB) design for total kneereplacementsurgeries can reduce the riskof tibial component loosening compared tofixed-bearing (FB) designs is still unclear.Arthroplastic surgeries developed rapidlywithin recent 10 years, but there is no similarstudy performed yet. This randomized studyinvestigated the impact of prosthesis design toloosening of components at 2 years for totalknee replacement surgeries.Materials and Methods: 479 patientswho underwent total knee arthroplastyin FirstCentral Hospital of Mongolia were allocated toeither FB or MB tibialarticulation.We comparedour results to similar studies which performedabroad due to there is no such a studyperformed before in Mongolia.Results: There is no significant differenceby age, sex, weight, height, body mass index,operation side (right or left) in both groups.Pre- and postoperative range of motionwasalmostsame for MB and FB groups.Butloosening complication was higher for the FBgroup (1.16%) than MB group (0%).Conclusion: Using MB design for total kneearthroplasty has less loosening complicationthan using FB design in Mongolians. Bonemineral density (dual energy absorptiometry)and radiostereometric analysis are necessaryfor widening studies in field of total kneereplacement surgeries in the future.
ABSTRACT
PURPOSE: To evaluate the neuroprotective effect of combination therapy of polyethylene glycol (PEG) and magnesium sulfate (MgSO4) after a spinal cord injury. MATERIALS AND METHODS: Twenty Sprague Dawley male rats (300-350 gm) had a spinal cord injury after T9/10 laminectomy using an Ohio State University (OSU) impactor under intraperitoneal anesthesia. The animals were randomized to receive either PEG (1 g/kg)+MgSO4 (300 mg/kg) or saline (2 ml) via carotid vein after 2 hours of injury and then every 6 hours for 5 times. The behavioral outcome assessments were performed on days 2, 4 and 7, and then every week using the Basso, Bresnahan, and Beattie (BBB) score and subscore. The animals also underwent sensory threshold testing using a von Frey monofilament device and gait analysis with Catwalk program before and 6 weeks after cord injury. The animals were sacrificed at the end of 6 weeks and histologic assessment was performed to measure the areas of white and gray matter. RESULTS: For the animals treated with PEG+MgSO4 and saline, the mean BBB scores at 6 weeks post-injury were 13.3+/-0.3, 11.4+/-0.2 and the BBB subscores were 9.1+/-1.1, 4.4+/-1.2 respectively (p<0.05). No significant differences were found in sensory testing and gait analysis between the two groups. Histologic assessment revealed no significant difference in gray matter sparing but the areas of white matter at the lesion epicenter were 0.68+/-0.2, 0.41+/-0.04 mm2 in the PEG+MgSO4 and saline groups respectively, which indicated significant sparing of white matter in PEG+MgSO4 group (p<0.05). CONCLUSION: The combination therapy of polyethylene glycol and magnesium sulfate improved the motor function and showed significant histological sparing of the spinal cord after an acute spinal cord injury in rats.