Background: The effectiveness of lumbar total disc replacement (TDR) with different prostheses for sagittal alignment has been reported previously. However, there are only few reports on Activ L TDR and no specific evidence regarding whether sagittal alignment affects the clinical outcomes.
Methods: Eighty-seven patients who underwent mono- or bi-segmental lumbar TDR with Activ L were studied. The films of the upright anteroposterior and lateral spine in neutral, flexion, and extension positions were obtained before surgery and at 1 month and 1 and 3 years after surgery. The radiographic parameters such as lumbar lordosis (LL), index level lordosis (IL), pelvic incidence (PI), pelvic tilt (PT), segmental lordosis (SL), and sacral slope (SS) were measured based on the lateral upright radiographs. Clinical outcomes were evaluated using the Oswestry Disability Index (ODI) and visual analog scale (VAS) pre- and post-operatively.
Results: Eighty-seven patients with complete radiographic data were available for a 3-year follow-up period. Of these, 66 received a single-level TDR, and 21 received a 2-level TDR. At 1 month, the mean LL was similar to the pre-operative data and then was significantly increased to 45.1° at 3 years. On average, the IL tended to significantly increase, while the mean SL at L-5 was increased from 16.5° pre-operatively to 21.0° at 3 years. The mean SL at L1-2, L2-3, L3-4, and L5-S1; PI; PT; and SS showed no obvious difference after 3 years. In contrast, VAS and ODI scores showed significant improvement after surgery.
Conclusions: Activ L TDR showed a favorable effect on sagittal alignment, enhancing the IL while preserving the LL and SS. However, satisfactory clinical results for over a 3-year follow-up were not affected by sagittal alignment.
Keywords: Activ L; Sagittal alignment; Total disc replacement.
Conflict of interest statement
The authors declare no financial and non-financial competing interests.
Ren H, Geng W, Ma J, Xu H, Li Z, Pang L, Li Kunpeng. Ren H, et al. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2015 Oct;29(10):1269-74. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2015. PMID: 26749737 Chinese.
Sun W, Lu S, Hai Y, Wang Q, Kang N, Zang L, Wang Y, Liu T, Liang D. Sun W, et al. Zhonghua Wai Ke Za Zhi. 2016 Feb 1;54(2):104-7. doi: 10.3760/cma.j.issn.0529-5815.2016.02.006. Zhonghua Wai Ke Za Zhi. 2016. PMID: 26876076 Chinese.
Sun XM, Xu HG, Xiao L, Liu C, Yang XM, Zhao QL, Nie WL. Sun XM, et al. Zhongguo Gu Shang. 2020 Jul 25;33(7):609-14. doi: 10.12200/j.issn.1003-0034.2020.07.004. Zhongguo Gu Shang. 2020. PMID: 32700482 Chinese.
Fei H, Li WS, Sun ZR, Ma QW, Chen ZQ. Fei H, et al. Orthop Surg. 2017 Aug;9(3):271-276. doi: 10.1111/os.12340. Orthop Surg. 2017. PMID: 28960822 Free PMC article.
Gille O, Challier V, Parent H, Cavagna R, Poignard A, Faline A, Fuentes S, Ricart O, Ferrero E, Ould Slimane M; French Society of Spine Surgery (SFCR). Gille O, et al. Orthop Traumatol Surg Res. 2014 Oct;100(6 Suppl):S311-5. doi: 10.1016/j.otsr.2014.07.006. Epub 2014 Sep 5. Orthop Traumatol Surg Res. 2014. PMID: 25201282 Review.
- Shuang F, Hou S. Present clinical research situation of adjacent segment degeneration after lumbar spinal fusion. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2013;27(1):110–115. – PubMed
- Wilke HJ, Schmidt R, Richter M, Schmoelz W, Reichel H, Cakir B. The role of prosthesis design on segmental biomechanics: semi-constrained versus unconstrained prostheses and anterior versus posterior centre of rotation. Eur Spine J. 2012;21(Suppl 5):S577–S584. doi: 10.1007/s00586-010-1552-1. – DOI – PMC – PubMed