Tortolani P Justin, Cunningham Bryan W, Eng Mmech, McAfee Paul C, Holsapple Gwen A, Adams Karen A
Scoliosis and Spine Center of Maryland, O'Dea Medical Arts Building, 7506 Osler Drive, Suite 104, Baltimore, MD 21204, USA.
J Bone Joint Surg Am. 2007 Jan;89(1):82-8. doi: 10.2106/JBJS.F.00432.
Despite reports of good clinical outcomes in patients treated with lumbar and cervical disc replacements, varying degrees of heterotopic bone have been observed around these devices. The purposes of the present study were to determine the prevalence of heterotopic ossification following lumbar disc replacement and to investigate whether heterotopic ossification results in loss of motion or negatively affects clinical outcome.
All preoperative and postoperative radiographs from a completed prospective, randomized, United States Food and Drug Administration-regulated trial comparing replacement with the CHARITE Artificial Disc with anterior interbody arthrodesis were analyzed. In each of 276 patients treated with disc replacement, heterotopic ossification was categorized with use of a validated 5-point radiographic classification system both preoperatively and at all protocol-specified follow-up intervals to two years. The range of motion on flexion and extension radiographs made preoperatively was compared with that on radiographs made two years postoperatively, and the motion was correlated with the presence or absence of heterotopic ossification. Similarly, validated clinical outcome measures were correlated with the presence or absence of heterotopic ossification at two years.
The prevalence of heterotopic ossification in the 276 consecutive patients treated with lumbar disc replacement with the CHARITE Artificial Disc was 4.3%. There were four cases of Class-I heterotopic ossification and eight cases of Class-II heterotopic ossification. In five of the twelve patients, heterotopic bone was visible as early as six weeks postoperatively, and eleven of the twelve patients had evidence of heterotopic ossification by three months postoperatively. The postoperative range of motion exceeded the preoperative range in all of the patients with heterotopic ossification. With the numbers available, no difference in either the range of motion or the clinical outcome at twenty-four months postoperatively was found between the patients who had and those who did not have heterotopic ossification.
Heterotopic ossification is infrequent in patients treated with the CHARITE Artificial Disc, and it does not impact the range of motion or clinical outcome.
尽管有报道称腰椎和颈椎间盘置换术治疗的患者临床效果良好，但在这些植入物周围观察到了不同程度的异位骨化。本研究的目的是确定腰椎间盘置换术后异位骨化的发生率，并调查异位骨化是否会导致活动度丧失或对临床结果产生负面影响。
分析了一项已完成的前瞻性、随机、美国食品药品监督管理局监管的试验的所有术前和术后X线片，该试验比较了CHARITE人工椎间盘置换术与前路椎间融合术。在276例接受椎间盘置换术的患者中，术前和术后所有方案规定的随访间隔至两年时，均使用经过验证的5分X线分类系统对异位骨化进行分类。将术前屈伸位X线片上的活动度与术后两年X线片上的活动度进行比较，并将活动度与异位骨化的有无进行关联。同样，将经过验证的临床结果指标与两年时异位骨化的有无进行关联。
276例连续接受CHARITE人工椎间盘腰椎置换术的患者中，异位骨化的发生率为4.3%。有4例I级异位骨化和8例II级异位骨化。12例患者中有5例术后6周即可见异位骨，12例患者中有11例术后3个月有异位骨化证据。所有异位骨化患者术后的活动度均超过术前。就现有数据而言，有异位骨化和没有异位骨化的患者在术后24个月时的活动度或临床结果均无差异。
使用CHARITE人工椎间盘治疗的患者中异位骨化并不常见，且不影响活动度或临床结果。
