人工髋关节表面置换术后血清金属离子浓度测定及影响因素分析

Detection and influence factor of serum metal ions concentration level after resurfacing arthroplasty of the hip

目的应用电感耦合等离子体质谱仪检测人工髋关节表面置换术(resurfacing arthroplasty of the hip,RSAH)后不同时间患者血清钴、铬以及钼离子浓度,探讨其影响因素。方法选择2005年6月-2014年11月行RSAH且术后历次随访关节功能良好(Harris评分>85分)的47例(55髋)患者作为研究对象。其中男25例,女22例;年龄18~64岁,平均49.7岁。髋臼发育不良(developmental dysplasia of the hip,DDH)18例(22髋),非DDH 29例(33髋)。术后随访时间6个月~5年,平均3.2年。应用电感耦合等离子体质谱仪测定血清钴、铬以及钼离子浓度,以6名正常自愿者血清金属离子浓度作为正常参照值进行比较。综合金属离子浓度测量结果分析,选择患者并根据髋臼假体位置以及股骨头假体直径分组比较,分析其与金属离子浓度的关系。对金属离子浓度与患者年龄、体质量指数、手术前后Harris评分以及股骨假体颈干角、柄干角进行相关分析。结果与正常参照值比较,置换术后患者钴离子浓度于术后1年时达峰值(P<0.05),之后缓慢下降,至术后4年时再次升高,术后5年时浓度接近术后2年水平;铬离子浓度于术后9个月达峰值(P<0.05),之后逐渐下降,至术后5年时接近正常水平;钼离子浓度总体呈逐渐上升趋势,术后5年浓度最高(P<0.05)。根据金属离子浓度测量结果综合分析,取术后随访9个月及1年的29例(35髋)患者进行分组分析。与髋臼假体外展角<40°及>45°组相比,40~45°组DDH及非DDH患者钴、铬离子浓度降低,差异均有统计学意义(P<0.05);钼离子浓度差异无统计学意义(P>0.05)。与髋臼假体前倾角<15°及>20°组相比,15~20°组患者钴、铬、钼离子浓度均显著降低(P<0.05)。股骨头直径≥48 mm组钴、铬、钼离子浓度均低于<48 mm组,但组间仅钴离子浓度差异有统计学意义(P<0.05)。相关分析示,钴离子浓度与术后Harris评分成负相关(r=-0.486,P=0.041)。结论 RSAH术后1年血清钴离子浓度明显高于正常水平,术后9个月铬离子明显升高,术后钼离子浓度呈持续上升趋势;各金属离子浓度与髋臼假体位置有密切关系。

Objective To observe the tendency of serum cobalt （Co）, chromium （Cr）, and molybdenum （Mo） ions concentration level after resurfacing arthroplasty of the hip （RSAH） by inductively coupled plasma mass spectrometer （ICP-MS）, and analyze the influence factors. Methods Forty-seven patients （55 hips） underwent RSAH between June 2005 and November 2014 who had good joint function （Harris score were 〉85） at every review time were selected in the study. There were 25 males and 22 females, with the mean age of 49.7 years （range, 18-64 years）. The disease causes included developmental dysplasia of the hip （DDH） in 18 cases （22 hips） and non-DDH in 29 cases （33 hips）. The follow-up time was 6 months to 5 years （mean, 3.2 years）. The concentrations of Co, Cr, and Mo ions were measured by ICP-MS, and were compared with those of 6 normal controls. Based on the analysis of the measured results, patients were chosen and grouped according to prosthesis position and femoral head prosthesis diameter. A correlative analysis was made between serum metal ions concentration and various factors （age, body mass index, pre- and post-operative Harris scores, neck-shaft angle, and stem-shaft angle）. Results The concentration of serum Co ion reached the peak at 1 year after operation （P〈0.05）, and then slowly decreased, increased again at 4 years after operation and was close to the 2nd-year level at 5 years. The concentration of serum Cr ion reached its peak at 9 months after operation （P〈0.05）, and then gradually decreased, and was close to normal level at 5 years. The concentration of serum Mo ion kept increase trend and reached the peak at 5 years （P〈0.05）. Thirty-five hips of 29 patients followed up 9 months and 1 year were grouped. For DDH and non-DDH patients, Co and Cr ion concentrations of 40-45° abduction angle of acetabular component were significantly lower than those of 〈40 and=＂＂〉45° （P〈0.05）, but there was no significant difference in Mo ion concentration （P〉0.05）. For all patients, Co, Cr, and Mo ion concentrations of 15-20° anteversion angle of acetabular component were significantly lower than those of 〈15 and=＂＂〉20° （P〈0.05）. Co, Cr, and Mo ion concentrations of ≥48 mm diameter of the femoral component were significantly lower than those of 〈48 mm （P〈0.05）. There was a negative correlation between Co ion and postoperative Harris score （r=-0.486,P=0.041）. Conclusion The serum Co and Cr ions concentrations increase obviously at 1 year and 9 months after RSAH operation, and Mo ion concentration displays an increase trend. The metal ions concentrations have close relationship with the position of acetabular component.