Department of Endocrine Research, Medical Hospital I, BG University Hospital Bergmannsheil Bochum, Bochum, Germany.
Department of Pain Medicine, BG University Hospital Bergmannsheil Bochum, Bochum, Germany.
Pain. 2019 Jun;160(6):1261-1269. doi: 10.1097/j.pain.0000000000001520.
Local osteopenia and altered bone metabolism are major complications of complex regional pain syndrome (CRPS), but quantitative assessment is difficult unless using X-ray or dual-energy X-ray absorptiometry. Ultrasound-based measurement of bone density (UBD) is a possible alternative but has never been used to detect unilateral disease such as CRPS. Therefore, the main outcome measure of this prospective study was the diagnostic utility of UBD in patients with lower-limb CRPS. Second, we compared the extent of unilateral and contralateral calcaneal bone density to that of other conditions with unilateral pain, general osteoporosis, and healthy subjects. Calcaneal osteodensitometry was bilaterally examined using ultrasound-based methodology. Bone mineral density values were converted to Z-scores based on age- and sex-dependent reference values. All patients completed a functional and an osteoporosis risk questionnaire. In patients with CRPS (n = 18), the bone mineral density values and Z-scores were significantly lower in both the affected (mean ± SD: 0.40 ± 0.08 and -1.1 ± 0.8, respectively) and nonaffected (0.46 ± 0.09 and -0.6 ± 0.9, respectively) limbs than in patients (n = 40) with other unilateral pain syndromes (affected: 0.51 ± 0.1 and -0.2 ± 1.1, respectively; nonaffected: 0.54 ± 0.11 and 0 ± 0.9, respectively) and healthy subjects (right side: 0.6 ± 0.1 and 0.1 ± 0.9, respectively). Conversely, in patients with known systemic osteoporosis, the Z-scores were lower bilaterally with smaller side-to-side differences than in those with CRPS (P < 0.05). Compared with subjects suffering from long-term CRPS (≥2.4 years), patients with shorter disease duration exhibited significantly lower Z-scores (P < 0.05). In conclusion, UBD revealed that CRPS is associated with both local and systemic alterations of bone metabolism.
局部骨质疏松症和骨代谢改变是复杂性区域疼痛综合征（CRPS）的主要并发症，但除非使用 X 射线或双能 X 射线吸收法，否则很难进行定量评估。基于超声的骨密度测量（UBD）是一种可能的替代方法，但从未用于检测单侧疾病，如 CRPS。因此，本前瞻性研究的主要结局测量指标是 UBD 在下肢 CRPS 患者中的诊断效用。其次，我们比较了单侧跟骨骨密度的程度与其他单侧疼痛、普遍骨质疏松症和健康受试者的情况。使用基于超声的方法双侧检查跟骨骨密度。将骨矿物质密度值转换为基于年龄和性别相关参考值的 Z 分数。所有患者均完成了功能和骨质疏松风险问卷。在 CRPS 患者（n=18）中，患侧（平均值±标准差：0.40±0.08 和-1.1±0.8）和非患侧（0.46±0.09 和-0.6±0.9）的骨矿物质密度值和 Z 分数均明显低于患有其他单侧疼痛综合征的患者（n=40）（患侧：0.51±0.1 和-0.2±1.1；非患侧：0.54±0.11 和 0±0.9）和健康受试者（右侧：0.6±0.1 和 0.1±0.9）。相反，在已知患有全身性骨质疏松症的患者中，双侧的 Z 分数较低，且两侧之间的差异较小，与 CRPS 患者相比（P<0.05）。与患有长期 CRPS（≥2.4 年）的患者相比，患病时间较短的患者的 Z 分数明显较低（P<0.05）。总之，UBD 显示 CRPS 与局部和全身骨代谢改变有关。
