人工颈椎间盘置换术后假体位置不良原因分析

Analysis of the influencing factors on the malposition following cervical disc replacement

[目的]探讨颈椎人工椎间盘置换术后假体位置不良的发生率及其影响因素。[方法]回顾分析2009年3月~2012年3月在本院接受颈椎人工椎间盘置换术的颈椎病患者,共56例,男32例,女24例;平均年龄（41.2±5.6）岁。统计术后假体位置不良的发生率,假体位置不良判断标准为术后颈椎侧位X线片上假体前缘位移〉1.5mm,或假体上下X线片成角〉1.5°。根据假体有无位置不良,将患者分为假体位置不良组和无假体位置不良组,并比较两组术前特征,分析何种特征影响术后假体位置。[结果]所有患者均获得随访,平均随访时间（34.3±5.6）个月。所有患者均获得满意的临床疗效。56例患者,共置入74个假体,其中单节段置入38例,双节段置入18例。术后假体位置不良7例（7个假体）,发生率为9.5%（7/74）。按接收手术时间比较,2009年3月~2010年3月、2010年3月~2011年3月及2011年3月~2012年3月,假体位置不良发生率分别为21.4%（3/14）、8.0%（2/25）、5.7%（2/35）,说明开展此手术的早期假体位置不良发生率较高,尽管差异无统计学意义（P〉0.05）。影像学检查显示,假体位置不良的患者较无假体位置不良患者,术前颈椎屈曲度变直或反曲的发生率明显增加（87.7%vs.38.8%,P=0.037）,术前平均ROM明显增加（11.0°±3.8°vs.9.1°±2.5°,P=0.040）,术前平均椎间盘-关节突角明显增加（127.9°±6.9°vs.121.1°±4.8°,P=0.000）。[结论]颈椎人工椎间盘置换术是一个容量性手术,有一个学习曲线;术前颈椎屈曲度不佳、手术节段活动度过大及椎间盘-关节突角过大对术后假体位置有重要影响。

[Objective] To explore the incidence of malposition of prosthesis following cervical disc replacement and the influencing factors on the malposition. [ Methods] A retrospective analysis 56 patients （32 males, 24 females） with a mean age of （41.2 ± 5.6） years was made, all patients were treated by cervical disc replacement from March 2009 to March 2012 in our hospital. The incidence of postoperative malposition of prosthesis was calculated, which was defined as a displacement of the prosthesis 〉 1.5 mm, or the angle of prosthetic piece 〉 1.5° . According to the presence or absence of malposition of prosthe- sis, the patients were divided into two groups - with and without malposition of prosthesis. The preoperative characteristics in both groups, were compared, and influencing on factors postoperative malposition of prosthesis were analyzed. [ Results] All patients were followed - up and the average follow - up time was （34. 3 ± 5.6） months. All patients were satisfied with the clin- ical outcome. Seventy -four prostheses were implanted in 56 patients. There was single segment in 38 cases and double segment in 18 patients. There were 7 cases （7 prostheses） with malposition of prosthesis; the incidence of malposition of prosthesis was 9.5% （7/74） . During March 2009 - March 2010, March 2010 - March 2011, and March 2011 - March 2012, the inci- dence of malposition of prosthesis were 21.4% （3/14）, 8. 0% （2/25）, and 5.7% （2/35）, respectively, which indicated that a higher incidence of malposition of prosthesis at the early period. Compared to the patients without malposition of prosthesis, patients with that had a higher incidence of preoperative straight or anti -flexion of the cervical spine （87. 7% vs. 38. 8%, P = 0. 037）, a higher preoperative ROM （ 11.0 ± 3.8 ° vs. 9. 1 ± 2. 5 °, P = 0. 040. ）, and a higher preoperative disc - facet angle （ 127.9 ± 6. 9 ° vs. 121.1 ± 4. 8 °, p =0. 000） . [ Conclusion] The cervical disc replacement is a capacity surgeryand need a learning curve. A poor preoperative flexion of the cervical spine, a large ROM of surgical segment, and a large disc - facet angle, are important influenceing factors on postop- erative position of prosthesis.