Myers M A, Casciani T, Whitbeck M G, Puzas J E
Department of Orthopaedics, University of Rochester, New York, USA.
Spine (Phila Pa 1976). 1996 Oct 15;21(20):2368-71. doi: 10.1097/00007632-199610150-00012.
Lateral dual-energy x-ray absorptiometry was used to examine isolated changes in vertebral body mineral density in humans after instrumented posterolateral lumbar fusion.
To determine if device-related osteopenia will occur in humans who undergo spinal fusion. Device-related osteopenia is known to occur as a result of local stress shielding after instrumentation in the appendicular skeleton. This effect has not been observed, however, in humans after spine fusion. To evaluate such changes, the vertebral body mineral density was measured in eight patients who had instrumented lumbar fusion and in eight matched control patients who had lumbar surgery with no fusion.
In previous studies of dogs, vertebral body osteopenia occurred as a result of instrumented spine fusions. Previous studies in humans, however, have been limited by the relative insensitivity of conventional photon absorptiometry to isolated changes in the vertebral body because of overlying posterior elements.
Absorptiometry was performed an average of 31.9 months after posterolateral fusion that bridged at least one level in the region of L2-L4. To reduce the effects of individual variations in mineral metabolism, the vertebral values were standardized by using the ratio of vertebral body to femoral neck density for each patient.
The mean density ratio for the group of patients who underwent spine fusion was 0.733. This value was significantly lower than the control ratio of 0.879 (P = 0.048).
Patients who have undergone instrumented posterolateral lumbar fusions have decreased vertebral body bone mineral density at the level of fusion compared with that of matched controls.
采用外侧双能X线吸收法检测后路腰椎融合内固定术后人体椎体骨密度的孤立变化。
确定接受脊柱融合术的患者是否会出现与器械相关的骨质减少。已知在四肢骨骼进行内固定后，由于局部应力遮挡会出现与器械相关的骨质减少。然而，在脊柱融合术后的人体中尚未观察到这种效应。为评估此类变化，对8例行腰椎融合内固定术的患者和8例接受非融合腰椎手术的匹配对照患者进行了椎体骨密度测量。
在先前对犬的研究中，脊柱融合内固定导致了椎体骨质减少。然而，先前的人体研究受到传统光子吸收法对椎体孤立变化相对不敏感的限制，因为有后方结构的覆盖。
在跨越L2-L4区域至少一个节段的后外侧融合术后平均31.9个月进行吸收测量。为减少矿物质代谢个体差异的影响，通过使用每位患者的椎体与股骨颈密度之比对椎体数值进行标准化。
接受脊柱融合术的患者组的平均密度比为0.733。该值显著低于对照组的0.879（P = 0.048）。
与匹配的对照组相比，接受后路腰椎融合内固定术的患者在融合节段的椎体骨密度降低。
