Spine Service, Hospital for Special Surgery, New York, NY, United States of America.
Endocrinology and Metabolic Bone Disease Service, Hospital for Special Surgery, New York, NY, United States of America.
Bone. 2021 Feb;143:115731. doi: 10.1016/j.bone.2020.115731. Epub 2020 Nov 4.
Spine fusion is one of the most common orthopedic surgeries, with more than 400,000 cases performed annually. While these procedures correct debilitating pain and deformities, complications occur in up to 45%. As successful fusion rests upon early stability of hardware in bone, patients with structural skeletal deficits may be at particular risk for complications. Few studies have investigated this relationship, and none have used higher order imaging to evaluate microstructural mechanisms for complications. Standard DXA measurements are subject to artifact in patients with spinal disease and therefore provide limited information. The goal of this prospective study was to investigate pre-operative bone quality as a risk factor for early post-operative complications using high resolution peripheral QCT (HR-pQCT) measurements of volumetric BMD (vBMD) and microarchitecture. We hypothesized that patients with low vBMD and abnormal microarchitecture at baseline would have more skeletal complications post-operatively. Conversely, we hypothesized that pre-operative DXA measurements would not be predictive of complications. Fifty-four subjects (mean age 63 years, BMI 27 kg/m) were enrolled pre-operatively and followed for 6 months after multi-level lumbar spine fusion. Skeletal complications occurred in 14 patients. Patients who developed complications were of similar age and BMI to those who did not. Baseline areal BMD and Trabecular Bone Score by DXA did not differ. In contrast, HR-pQCT revealed that patients who developed complications had lower trabecular vBMD, fewer and thinner trabeculae at both the radius and tibia, and thinner tibial cortices. In summary, abnormalities of both trabecular and cortical microarchitecture were associated the development of complications within the first six months following spine fusion surgery. Our results suggest a mechanism for early skeletal complications after fusion. Given the burgeoning number of fusion surgeries, further studies are necessary to investigate strategies that may improve bone quality and lower the risk of post-operative complications.
脊柱融合是最常见的骨科手术之一，每年有超过 40 万例手术。虽然这些手术可以纠正使人衰弱的疼痛和畸形，但仍有高达 45%的患者会出现并发症。由于融合的成功依赖于硬件在骨骼中的早期稳定性，因此结构性骨骼缺陷的患者可能特别容易出现并发症。很少有研究调查这种关系，也没有使用更高阶的影像来评估并发症的微观结构机制。在患有脊柱疾病的患者中，标准的 DXA 测量会受到伪影的影响，因此提供的信息有限。本前瞻性研究的目的是使用高分辨率外周 QCT（HR-pQCT）测量体积骨密度（vBMD）和微结构来研究术前骨质量作为术后早期并发症的危险因素。我们假设基线时 vBMD 低和微结构异常的患者术后会有更多的骨骼并发症。相反，我们假设术前 DXA 测量不会预测并发症。54 名患者（平均年龄 63 岁，BMI 27kg/m）在多节段腰椎融合术前入组，并在术后 6 个月进行随访。14 名患者发生了骨骼并发症。发生并发症的患者与未发生并发症的患者年龄和 BMI 相似。基线时 DXA 的面积 BMD 和小梁骨评分没有差异。相比之下，HR-pQCT 显示，发生并发症的患者桡骨和胫骨的小梁 vBMD 较低，小梁数量较少且较薄，胫骨皮质也较薄。总之，在脊柱融合手术后的前 6 个月内，小梁和皮质微结构的异常都与并发症的发展有关。我们的结果提示了融合术后早期骨骼并发症的发生机制。鉴于融合手术数量的不断增加，有必要进一步研究可能改善骨质量和降低术后并发症风险的策略。
