S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) Theses (Master's Degree_의학과)
Longitudinal changes in segmental range of motion following cervical artificial disc replacement
경추 인공 디스크 치환술 이후 시간에 따른 수술 분절의 움직임의 변화
- 의과대학 의학과
- Issue Date
- 서울대학교 대학원
- anterior cervical; discectomy; artificial disc replacement; range of motion; implanted; segment; longitudinal
- 학위논문 (석사)-- 서울대학교 대학원 : 의학과, 2017. 2. 정영섭.
Cervical artificial disc replacement (ADR) has emerged as a popular new treatment because of its potential benefit of averting an adjacent segment disease following ACDF. However, ADR also has problems such as heterotopic ossification, or mechanical failure, which raises concerns that the artificial disc would lose its function at some point.
To estimate the life expectancy of artificial disc, we analyzed longitudinal changes in the range of motion at the implanted segment during follow-up in a cohort of patients with healthy facet joints before surgery.
Patients and methods
We reviewed the charts and radiologic studies of 30 patients operated upon by ADR with Mobi-C in single level since 2006. All patients had healthy cervical facet joints (less than or equal to grade 1 according to grading systems for cervical facet joint degeneration) preoperatively. We assessed clinical outcomes with neck disability index (NDI) and visual analogue pain score (VAS) on neck and arm over follow-up and also measured the ROM at the implanted segment on dynamic radiographs during follow-up. The mean follow-up period was 42.4 ± 15.9 months. We then assessed the linearity of the changes in the ROM at the implanted segment in a linear mixed model.
All patients showed improved clinical outcomes. On average, the NDI, VAS on neck and arm improved with representing 74%, 76% and 92% improvement.
ROMs at the implanted segment were maintained at slightly increased levels until 24 months postoperatively (P=0.529). However, after 24 months, ROMs at the implanted segment decreased significantly until last follow-up (P<0.001). In addition, the decreasing pattern after 24 months showed a regular regression (P<0.001). Based on this regular regression, we estimated that ROMs at the implanted segments would be less than 2 degrees at 10.24 years postoperatively.
In the present study, we could assume that the implanted segment would lose its motion at 10.24 years after artificial disc replacement. In other words, an artificial disc may lose its function someday.
Keywords: anterior cervical
artificial disc replacement (ADR)
range of motion (ROM)