Dalenberg D D, Asher M A, Robinson R G, Jayaraman G
Section of Orthopedic Surgery, University of Kansas Medical Center, Kansas City.
Spine (Phila Pa 1976). 1993 Oct 1;18(13):1862-6. doi: 10.1097/00007632-199310000-00023.
A canine spine surgery model was used to study bone mineral loss induced in vertebrae bypassed by stiff implants. Loosening of implants was measured, and a determination was made as to the effect of loosening on the degree of bone mineral loss. Sixteen dogs were implanted with a rigid screw-rod construct and randomized to one of four groups depending on the motion segments immobilized. No fusions were performed. Bone mineral was studied by DEXA at baseline, and postoperatively at 3, 6, and 9 months. Loosening measurements were made at the implant-implant interface and the implant-bone interface at 9 months postoperatively. Results show that bone mineral loss occurred uniformly at 3 months postoperatively in vertebrae spanned by the implants, with the average bone mineral density at 3 months representing 81% of baseline. When the implant remained secure, bone mineral loss persisted at 6 and 9 months but did not worsen. When the implants loosened, there was recovery of bone mineral to the baseline level by 9 months postoperative.
使用犬类脊柱手术模型来研究由刚性植入物绕过的椎骨中诱导的骨矿物质流失。测量植入物的松动情况，并确定松动对骨矿物质流失程度的影响。16只狗植入了刚性螺杆结构，并根据固定的运动节段随机分为四组。未进行融合手术。在基线时以及术后3、6和9个月通过双能X线吸收法（DEXA）研究骨矿物质。在术后9个月时在植入物-植入物界面和植入物-骨界面进行松动测量。结果表明，在植入物跨越的椎骨中，术后3个月骨矿物质流失均匀发生，3个月时的平均骨矿物质密度为基线的81%。当植入物保持稳固时，骨矿物质流失在6个月和9个月时持续存在但没有恶化。当植入物松动时，术后9个月骨矿物质恢复到基线水平。
