Jigang LOU, Huibo LI, Xin RONG, Wenjie WU, Hao LIU

Location change of center of rotation after single-level cervical total disc replacement with ProDisc-C

Objective: Previous studies reported that the location of the center of rotation (COR) at instrumented level after cervical total disc replacement (TDR) deviated from its preoperative location. However, currently, it is unknown whether the deviated COR is linked to the range of motion (ROM) at instrumented level. The purpose of this study was to evaluate the clinical outcomes after cervical TDR with ProDisc-C (Synthes, West Chester, PA, USA), as well as investigate the location change of COR at instrumented level and its clinical significance.Methods: A total of 23 patients who underwent single-level cervical TDR with ProDisc-C were included. Japanese Orthopaedic Association ( JOA) score and Neck Disability Index (NDI) were used to assess clinical outcomes. Radiographic parameters such as cervical ROM, instrumented segmental ROM, adjacent segmental ROM, and intervertebral height were analyzed. Additionally, the location change of COR at instrumented level and its clinical significance were further analyzed by the alteration of its coordinates (COR-X, COR-Y).Results: JOA scores increased significantly, while NDI scores decreased at final follow-up. No differences were found in cervical global ROM, instrumented segmental ROM, adjacent segmental ROM, and COR-Y at instrumented level between preoperative and final follow-up measurements (p>0.05); however, intervertebral height and COR-X increased significantly (p<0.05).Conclusion: Cervical global ROM, instrumented segmental ROM, and adjacent segmental ROM could be effectively maintained, and intervertebral height was increased after TDR with ProDisc-C. The location of COR at instrumented level shifted forward after cervical TDR.

___

Bohlman HH, Emery SE, Goodfellow DB, Jones PK. Robinson anterior cervical discectomy and arthrodesis for cervical radiculopathy. Long-term follow-up of one hundred and twenty-two patients. J Bone Joint Surg Am 1993;75:1298-307.

Epstein NE. Anterior cervical diskectomy and fusion with- out plate instrumentation in 178 patients. J Spinal Disord 2000;13:1-8.

Yue WM, Brodner W, Highland TR. Long-term results after anterior cervical discectomy and fusion with allograft and plating: a 5- to 11-year radiologic and clinical follow- up study. Spine (Phila Pa 1976) 2005;30:2138-44.

Hilibrand AS, Carlson GD, Palumbo MA, Jones PK, Bohlman HH. Radiculopathy and myelopathy at segments adjacent to the site of a previous anterior cervical arthrod- esis. J Bone Joint Surg Am 1999;81:519-28.

Matsunaga S, Kabayama S, Yamamoto T, Yone K, Sakou T, Nakanishi K. Strain on intervertebral discs after anterior cervical decompression and fusion. Spine 1999;24:670-5.

Eck JC, Humphreys SC, Lim TH, Jeong ST, Kim JG, Hodges SD, et al. Biomechanical study on the effect of cer- vical spine fusion on adjacent-level intradiscal pressure and segmental motion. Spine 2002;27:2431-4.

Wigfield C, Gill S, Nelson R, Langdon I, Metcalf N, Robertson J. Influence of an artificial cervical joint com- pared with fusion on adjacent-level motion in the treat- ment of degenerative cervical disc disease. J Neurosurgery 2002;96:17-21.

Koller H, Meier O, Zenner J, Mayer M, Hitzl W. In vivo analysis of cervical kinematics after implantation of a mini- mally constrained cervical artificial disc replacement. Eur Spine J 2013;22:747-58.

Barrey C, Champain S, Campana S, Ramadan A, Perrin G, Skalli W. Sagittal alignment and kinematics at instru- mented and adjacent levels after total disc replacement in the cervical spine. Eur Spine J 2012;21:1648-59.

Duggal N, Bertagnoli R, Rabin D, Wharton N, Kowalczyk I. ProDisc-C: an in vivo kinematic study. J Spinal Disord Tech 2011;24:334-9.

Rousseau MA, Cottin P, Levante S, Nogier A, Lazennec JY, Skalli W. In vivo kinematics of two types of ball-and- socket cervical disc replacements in the sagittal plane: cra- nial versus caudal geometric center. Spine (Phila Pa 1976) 2008;33(1): E6-9.

Lim MR, Girardi FP, Zhang K, Huang RC, Peterson MG, Cammisa FP Jr. Measurement of total disc replacement radiographic range of motion: a comparison of two tech- niques. J Spinal Disord Tech 2005;18:252-6.

Malham GM, Parker RM, Ellis NJ, Chan PG, Varma D. Cervical artificial disc replacement with ProDisc-C: clini- cal and radiographic outcomes with long-term follow-up. J Clin Neurosci 2014;21:949-53.

Murrey D, Janssen M, Delamarter R, Goldstein J, Zigler J, Tay B, et al. Results of the prospective, randomized, con- trolled multicenter Food and Drug Administration inves- tigational device exemption study of the ProDisc-C total disc replacement versus anterior discectomy and fusion for the treatment of 1-level symptomatic cervical disc disease. Spine J 2009;9:275-86.

Zigler JE, Delamarter R, Murrey D, Spivak J, Janssen M. ProDisc-C and anterior cervical discectomy and fusion as surgical treatment for single-level cervical symptom- atic degenerative disc disease: five-year results of a Food and Drug Administration study. Spine (Phila Pa 1976) 2013;38:203,9.

Zhao YB, Sun Y, Zhou FF, Liu ZJ. Cervical disc arthro- plasty with ProDisc-C artificial disc: 5-year radiographic follow-up results. Chin Med J (Engl) 2013;126:3809-11.

Barna M, Stulík J, Kryl J, Vyskocil T, Nesnídal P. ProDisc- C Total Disc Replacement. A four-year prospzctive mono- centric study. [Article in Czech] Acta Chir Orthop Trau- matol Cech 2012;79:512-9. [Abstract]

Kowalczyk I, Lazaro BC, Fink M, Rabin D, Duggal N. Analysis of in vivo kinematics of 3 different cervical de- vices: Bryan disc, ProDisc-C, and Prestige LP disc. J Neu- rosurg Spine 2011;15:630,5.

Lazaro BC, Yucesoy K, Yuksel KZ, Kowalczyk I, Rabin D, Fink M, et al. Effect of arthroplasty design on cervical spine kinematics: analysis of the Bryan Disc, ProDisc-C, and Synergy disc. Neurosurg Focus 2010;28:E6.

Lee CS, Lee DH, Hwang CJ, Kim H, Noh H. The effect of a mismatched center of rotation on the clinical outcomes and flexion-extension range of motion: lumbar total disk replacement using mobidisc at a 5.5-year follow-up. J Spi- nal Disord Tech 2014;27:148-53.

Galbusera F, Anasetti F, Bellini CM, Costa F, Fornari M. The influence of the axial, antero-posterior and lateral po- sitions of the center of rotation of a ball-and-socket disc prosthesis on the cervical spine biomechanics. Clin Bio- mech (Bristol, Avon) 2010;25:397-401.

Colle KO, Butler JB, Reyes PM, Newcomb AG, Theodore N, Crawford NR. Biomechanical evaluation of a metal- on-metal cervical intervertebral disc prosthesis. Spine J 2013;13:1640-9.

Kelly BP, Zufelt NA, Sander EJ, DiAngelo DJ. The influ- ence of fixed sagittal plane centers of rotation on motion segment mechanics and range of motion in the cervical spine. J Biomech 2013;46:1369-75.