Skip to main content

Mid-long-term follow-up of operated level kinematics after single-level artificial cervical disc replacement with Bryan disc

Abstract

Objective

Evaluation of the mid-long-term kinematics of single-level Bryan artificial cervical disc replacement (ACDR) in vivo by analyzing the center of rotation (COR) at the operated level.

Methods

A retrospective analysis was conducted using data collected from 38 patients who underwent single-level Bryan ACDR from January 2010 to March 2013. Radiological parameters including range of motion (ROM), lordosis angle, translation, and COR were obtained. Clinical outcomes were assessed based on Odom Criteria, modified Japanese Orthopedic Association (mJOA), Neck Disability Index (NDI), and Visual Analogue Scale (VAS) scores. Correlations between COR and other follow-up data were discussed at the last follow-up.

Results

Compared with preoperative values, the last follow-up data showed that 86.84% of cases achieved good-or-excellent outcomes based on Odom criteria; Significant improvements were observed across all scales assessed for clinical outcomes (P < 0.05); Lordosis angle was significantly increased in both the overall cervical spine and the operated level (P < 0.05); ROM of the overall cervical spine, operated level, and adjacent levels was preserved (P > 0.05); There was no significant change in COR at the operated level (P > 0.05). At the last follow-up and at the operated level, COR (Y) showed negative correlations with ROM and translation (P < 0.05), but no follow-up data correlated with COR (X) were found (P > 0.05).

Conclusions

Satisfactory clinical and radiological outcomes were achieved 7 years or more after single-level Bryan ACDR. At the operated level, preoperative COR was maintained, probably due to replicating the physiological interrelations of COR (Y), translation, and ROM.

Introduction

Artificial cervical disc replacement (ACDR) is a procedure aimed at anterior intervertebral decompression and the subsequent reconstruction of mobility for symptomatic cervical degenerative disc disease (CDDD). Based on data from short- and mid- to long-term follow-up studies, ACDR has shown similar clinical outcomes to anterior cervical discectomy and fusion (ACDF). Moreover, since motion at the operated level can be preserved, it is considered that ACDR may delay or even prevent adjacent segment degeneration (ASD) through reduction of mechanical load and compensatory motion at the adjacent levels compared with cervical fusion [1, 2]. A number of publications have already demonstrated the successful preservation of range of motion (ROM) at the operated level, but the purpose of ACDR is to restore the cervical physiological motion after nerve decompression, and the physiological motion patterns may influence the long-term clinical outcomes of ACDR through prolonged viability of the implants, reduction of stress at zygapophyseal joints, and improvement of the kinematics and biomechanics at adjacent levels [3,4,5]. Thus, attention is increasingly shifting to in vivo kinematics analysis of the artificial cervical disc [6].

Due to the lack of a simple and effective method to evaluate three-dimensional cervical motion, cervical kinematics studies are mainly based on sagittal flexion–extension motion [7]. The center of rotation (COR) is the sagittal motion center of the functional spinal unit (FSU) measured using cervical flexion–extension radiographs [7, 8]. COR is relatively simple to measure and can be readily subjected to statistical analysis and comparison. Unlike ROM, which amounts to the sum of declination angles generated by intervertebral rotation and translation, COR constitutes a combination of sagittal motion informations of the cervical FSU and enables the delineation of the quality and trajectory of intervertebral motion [9, 10], interpretation of the biomechanical environment and stability of the index level [4, 11, 12], and detection of irregular motion patterns of the FSU when ROM does not show any abnormality [13]. Due to these advantages, COR has been commonly adopted for kinematics analysis after ACDR [14, 15].

The Bryan cervical disc (Medtronic Sofamor Danek, Memphis, TN, USA), with its ability to simulate physiological kinematics, was once one of the most widely used artificial cervical discs in cervical spine surgery. Satisfactory clinical outcomes have been shown in 10- [16], 15- [17], and 18-year [18] follow-up studies for Bryan ACDR. However, detailed postoperative kinematics analysis of mid- to long-term follow-up is needed, and the factors that may affect the location of COR at the operated level remain to be determined. This study is aimed at a mid-long-term (at least 7 years) kinematics analysis of single-level Bryan ACDR and the investigation of potential factors correlated to COR with data gathered at the last follow-up.

Materials and methods

Patient populations

This study is a retrospective analysis of consecutive cases that underwent single-level Bryan ACDR in our hospital between January 2010 and March 2013. Inclusion criteria are: (1) patients were diagnosed with symptomatic CDDD based on radiological and clinical findings and failed to show improvement after non-surgical treatment for over 6 weeks; (2) age of patients was between 30 and 60 years; (3) operations were performed by the same surgeon; (4) the follow-up period was longer than 84 months. Exclusion criteria are: (1) patients with the following conditions were not considered as suitable candidates for ACDR: evident cervical instability, severe collapse of intervertebral space, marked reduction of ROM, cervical spinal bony stenosis, etc.; (2) patients received secondary operation. This study was approved by the Medical Ethics Committee of Dongzhimen Hospital (ethical approval number: 2021DZMEC-082-02). All patients were informed in advance and voluntarily consented to participate in the study.

Assessment of clinical outcomes

The modified Japanese Orthopedic Association (mJOA), visual analogue scale (VAS), and Neck Disability Index (NDI) scores were determined preoperatively and postoperatively at least 7 years in order to assess the clinical outcomes of Bryan ACDR. The mJOA score was used to assess motor, sensory, and sphincter dysfunction. Neck and arm pain related to CDDD were quantified using VAS score, and limitations in daily activities were assessed with NDI score. The Odom Criteria was used at the last follow-up to rate the clinical outcomes as follows: (a) excellent, all preoperative symptoms relieved, daily life and occupation not impaired; (b) good, occasional reemergence or minimal persistence of preoperative symptoms but no significant interference with daily occupational tasks; (c) satisfactory, relief of some preoperative symptoms, but daily occupational tasks and activities remain significantly impaired; (d) poor, symptoms and signs unimproved or exacerbated. Two formulas were used to calculate the improvement rate of clinical outcomes: the mJOA improvement rate, [(postoperative score − preoperative score)/(17 − preoperative score)] * 100%; the NDI or VAS improvement rate, [(preoperative score − postoperative score)/preoperative score] * 100%.

Radiographic assessment

The cervical radiographs in neutral–lateral and flexion–extension positions were collected before and 7 years or more after operation. Radiological parameters were measured independently by two orthopedic surgeons using Mimics 17.0 (Materialise, Leuven, Belgium) and ImageJ (Wayne Rasband, National Institutes of Health, USA) software. Every parameter was measured 3 times, and the average was used for further analysis.

The Cobb’s angle was applied to determine the lordosis angle of the overall cervical spine (C2–C7) and operated level in a neutral–lateral radiograph, as well as the ROM of the overall cervical spine (C2–C7), operated level, and adjacent levels (superior range of motion, SROM; inferior range of motion, IROM) in flexion–extension radiographs (Fig. 1). The translation at the operated level was quantified by measuring the sagittal displacement distance of the inferior anterior tip of the prosthesis’s superior endplate along the parallel line of the prosthesis’s inferior endplate during flexion and extension (Fig. 2) [19,20,21].

Fig. 1
figure 1

Radiographic measurements using the Cobb’s angle. a In the neutral–lateral radiograph, the lordosis angle of the overall cervical spine (red lines) and operated level (yellow lines) was defined as the angles between the tangents of the corresponding vertebral endplates. A positive value was assigned to an angle with an anterior opening, while the negative value presented the posterior opening. b, c In the flexion–extension radiographs, the overall cervical ROM and segmental ROM (ROM of the operated level, SROM, and IROM) were the flexion–extension difference of the overall cervical lordosis angle and intervertebral angle (between the two yellow lines), respectively

Fig. 2
figure 2

Measurement of the translation at the operated level. The flexion and extension radiographs were superimposed by aligning the inferior vertebrae. The tangent (in red) of the inferior endplate of the prosthesis was made, and the two lines perpendicular to the red line, touching the inferior anterior tip of the superior endplate of the prosthesis in flexion (line in white) and extension (line in black), were erected. The vertical distance between these two parallel lines was determined as the translation

The COR at the operated level was determined using the method of perpendicular bisectors based on Euler’s rotation theorem [22]. The sagittal motion trajectory of the superior vertebra relative to the inferior vertebra within an FSU is considered as an arc surrounding COR, and the COR can be determined through geometric measurement by: (1) superimposing the flexion and extension radiographs with the alignment of the inferior vertebrae; (2) connecting corresponding anatomical landmarks in the two superior vertebrae with a straight line and erecting perpendicular bisectors for those lines; (3) determining the point where all perpendicular bisectors meet. This point corresponds to the COR (Fig. 3) [23, 24]. To minimize technical errors, the following procedures were implemented: (1) cases with ROM < 5° at the operated level were not included due to the difficulties involved in locating and connecting the set of markers in the radiographs [25]; (2) the automatic registration function in Mimics 17.0 software was used to accurately superimpose the inferior vertebrae of the target FSU in the flexion–extension radiographs [24]; (3) a rectangular coordinate system was established around the inferior vertebral body in order to describe the location of COR, and the X- and Y-axis were aligned to distinct profiles of the vertebral body following the methods described by Amevo et al. [26]. The horizontal and vertical coordinates of COR were normalized against the width and height of the inferior vertebral body [27].

Fig. 3
figure 3

Measurement of the COR at the operated level (C5–C6). ac Aided by the alignments between P1–P5 and P1'–P5' in C6 vertebra, the flexion and extension radiographs were superimposed. c Three anatomical landmarks in C5 vertebra were located and labeled as P6–P8 in the flexion. Similarly, the corresponding markers were labeled as P6'–P8' in the extension. d COR was determined as the converging point of the three perpendicular bisectors (corresponding to segments P6P6', P7P7', and P8P8'). Referring to the procedures outlined by Amevo et al. [26], a rectangular coordinate system was set up using the tangents of C6 vertebral body. The forward and upward directions are positive directions of the X- and Y-axis, respectively. OX1 and OY1 correspond to the width and height of C6 vertebral body, respectively. The location of COR is noted as the following, COR (X, Y) = [(OX2/OX1) * 100%, (OY2/OY1) * 100%]

Statistical analysis

The SPSS 20.0 software (SPSS, Chicago, IL, USA) was used for statistical analysis of all the data. The results were presented as mean ± standard deviation (SD). Paired t-test and Pearson’s correlation analysis were applied to test for significant differences and correlations, respectively. P < 0.05 was considered statistically significant.

Results

Follow-up data of 41 patients were obtained. At the last follow-up, 3 patients developed grade III–IV heterotopic ossification and ROM < 5° at the operated level. These 3 cases were excluded due to large errors in measuring COR [25], and a total of 38 patients (18 males and 20 females) were eventually included in the study, with a mean age of 46.86 ± 6.91 years (range 34–59 years) at index surgery. Preoperative symptoms were attributed to myelopathy (24 cases), radiculopathy (7 cases), and myeloradiculopathy (7 cases). Operated levels included C3–C4 (1 case), C4–C5 (15 cases), C5–C6 (21 cases), and C6–C7 (1 case). The mean follow-up was 93.97 ± 9.67 months (range 84–118 months). Basic information about the patients is listed in Table 1.

Table 1 Basic information

Clinical outcomes

At the last follow-up, sensory, motor, and sphincter dysfunction caused by CDDD were significantly improved, and neck and arm pain were significantly alleviated. In contrast to preoperative values, the mJOA score was significantly increased (P < 0.05) with an 80.62 ± 13.59% rate of improvement; the NDI and VAS (neck and arm pain) scores were significantly reduced (P < 0.05) with a mean improvement rate of 72.18 ± 12.81%, 76.73 ± 16.95%, and 76.15 ± 9.06%, respectively (Table 2). 86.84% of patients ranked in the “excellent” or “good” category based on the Odom criteria at the last follow-up (Excellent, 23 cases; Good, 10 cases; Satisfactory, 5 cases; Poor, 0 cases).

Table 2 A summary of clinical outcomes

Radiological outcomes

As shown in Table 3, overall cervical ROM, ROM of the operated level, SROM, and IROM were well preserved and showed no significant difference compared with preoperative values (P > 0.05). Cervical lordosis was partially restored, and the lordosis angle of the overall cervical spine and the operated level increased from 11.29 ± 7.51° and 3.18 ± 4.60° preoperatively to 18.44 ± 9.62° and 5.64 ± 4.50° at the last follow-up, respectively (P < 0.05).

Table 3 A summary of radiological parameters

The location of COR at the operated level was maintained, and COR (X) and COR (Y) showed no significant difference between preoperation and the last follow-up (P > 0.05) (Table 3). The COR (Y) at the operated level showed negative correlations with the ROM and translation at the same level (r =  − 0.622, P < 0.05; r =  − 0.767, P < 0.05), but no correlation with clinical outcomes and remaining radiological parameters (P > 0.05). No correlation was found between the COR (X) and any of the parameters analyzed in this study (P > 0.05) (Table 4). Moreover, the ROM of the operated level was positively correlated to translation at the same level (r = 0.772, P < 0.05).

Table 4 Correlations between COR and other follow-up data at the last follow-up

Discussion

The implantation of an artificial cervical disc is aimed at avoiding the interference with cervical biomechanics and kinematics due to the fusion at the operated level and preventing stress concentration and abnormal motion at the adjacent levels. However, it has been sporadically noticed that implantation of the Bryan disc failed to maintain lordosis at the operated level and even caused focal kyphosis [28]. This problem may be the result of suboptimal insertion depth and angle of the prosthesis, uneven- or over-milling of the endplates, or a mismatch in the shape and size of the interface between the prosthesis and the vertebra, and technical improvements targeting these issues are expected to prevent kyphosis at the operated level [20, 29]. In agreement with previous reports [30], this study showed that single-level Bryan ACDR resulted in partial restoration of the physiological lordosis, not only at the operated level but also for the overall cervical spine, while promoting sagittal balance of cervical vertebral alignment. We suggest that the following factors will contribute to the proper restoration of the physiological cervical angle: (1) preoperative screen of indication to exclude patients with segmental instability and kyphosis; (2) preservation of posterior longitudinal ligament and minimization of soft tissue damage during the operation; (3) the milling is parallel to the intervertebral space to avoid overmilling of the anterior and posterior edges of the endplates; (4) postoperative functional training to promote recovery of soft tissue.

In this study, we observed no significant difference of the COR at the operated level 7 years or more after operation compared with that before operation. This observation indicates that the implantation of the Bryan disc did not change the original sagittal motion patterns and therefore ensured the long-term stability of the motion quality at the operated level, which may be the underlying explanation for the observed successful mid-long-term maintenance of the normal cervical biomechanical environment and the favorable clinical outcomes. The ability of the Bryan disc to maintain the COR at the operated level has been confirmed by several clinical reports [3, 15, 31, 32] and finite element analyses [14, 33].

The maintenance of the COR at the operated level is closely associated with the kinematic characteristics of the artificial cervical disc, which are determined by the design and structure of the prosthesis [6]. The Bryan disc is the first truly non-constrained artificial cervical disc used in clinical applications [34]. It contains a proprietary-enclosed nucleus pulposus, which is relatively flexible in sheath and can provide free adjustment of instantaneous center of rotation (ICR) at the operated level during cervical sagittal motion, thus simulating the constant shift of ICR under physiological conditions. This is considered a major factor contributing to the maintenance of the preoperative COR. In contrast, a constrained prosthesis such as the ProDisc-C disc allows only a singular sagittal motion pattern without translation and has a fixed COR/ICR based on the structure of the device, thus resulting in an anterior shift of COR at the operated level if the insertion depth was insufficient [35,36,37]. The intermediate semi-constrained prosthesis permits small translation and limited sagittal adjustment of ICR. To some degree, these characteristics are able to relax the requirement for the precise location of implantation, but maintenance of preoperative COR is still very difficult to achieve, for example, with the Prestige LP disc [8, 38,39,40].

At the last follow-up, statistical correlation analysis showed that COR (Y) was significantly negatively correlated with ROM and translation at the operated level. A similar correlation between COR (Y) and translation from a follow-up study of single-level Discover ACDR was reported by Koller et al. [21]. The cervical intervertebral joint is a 3-joint complex, and the motions of the disc and zygapophyseal joints are coupled. Because the zygapophyseal joint space relative to the intervertebral disc space is tilted at various angles, the sagittal intervertebral motion involves different directional motion components of both translation and rotation [19, 41]. Rotation refers to the rotational motion of the superior vertebra relative to the inferior vertebra around a specific point within the disc (Fig. 4a) [42]. We term this point “rotation ICR”. In contrast, translation is defined as the sliding of the superior vertebra along the superior endplate of the inferior vertebra [43]. However, due to the support of the biconvex disc, the trajectory of translation naturally presents an arc shape, which can be considered as the result of a complex motion of superior–inferior and anterior–posterior translation [19]. Therefore, the translation is actually a rotation around a point far below the disc (Fig. 4b) [42]. This point is termed “translation ICR”. In terms of localization along the superior–inferior direction, the COR is located between the superior rotation ICR and the inferior translation ICR (Fig. 4c), and the COR (Y) will change if the proportion of rotation or translation component in the sagittal intervertebral motion is altered. The increase of rotational proportion leads to the superior shift of COR, while the increase in translational proportion leads to the inferior shift of COR [44]. Bogduk et al. [22] summarized the interrelations among translation (T), rotation (θ), COR (Y), and center of reaction (CR) with the following formula: COR (Y) = CR (Y) − T/[2 tan(θ/2)]. These are consistent with our results. In other words, for the operated level with rotation as the main component of sagittal intervertebral motion, the COR was located close to the superior endplate of the inferior vertebra and within the disc (Fig. 5a), whereas the COR shifted inferiorly when the translational proportion increased (Fig. 5bc).

Fig. 4
figure 4

Effects of intervertebral rotation and translation on COR (Y). ac The angle between the two tangents of the posterior edge of the superior vertebral bodies in flexion and extension positions is defined as the ROM of the target FSU (White method [43]). a The ICR is located within the disc in the case of intervertebral motion with only rotation. b The ICR is located far below the disc in intervertebral motion with only translation. c Because the physiological intervertebral motion consists of both rotation and translation, the COR in the superior–inferior direction is located between the rotation ICR and the translation ICR. A, anterior; P, posterior

Fig. 5
figure 5

Three representative cases illustrate the interrelations among translation, ROM, and COR (Y) at the operated level. ac Superimpose the flexion and extension radiographs with the alignment of the inferior vertebrae. The vertical distance between the yellow solid and broken lines represents the translation. The angle between the black solid and broken lines defined as the ROM. a Female of 49-year-old patient with C5–C6 as the operated level and 88 months of follow-up. Translation: 0.4 mm; ROM: 6.21°; COR (Y): 102.86%. b Male of 36-year-old patient with C5–C6 as the operated level and 89 months of follow-up. Translation: 1.1 mm; ROM: 10.05°; COR (Y): 90.63%. c Female of 51-year-old patient with C5–C6 as the operated level and 93 months of follow-up. Translation: 1.6 mm; ROM: 12.34°; COR (Y): 62.23%

The translation causes the superior vertebra to tilt relative to the inferior vertebra in the sagittal plane (Fig. 4b). Therefore, the ROM of the cervical FSU should be defined as the sum of the relative declination angles between two adjacent vertebrae generated by both rotation and translation (Fig. 4c) [43]. Correspondingly, we observed that translation was positively correlated with ROM in this study, and similar findings were described in another follow-up study [21]. Combined with the foregoing findings, it can be seen that with the increase of translation, ROM increases and COR shifts inferiorly. Therefore, at the operated level, we found that greater ROM was associated with lower COR, i.e. there was a negative correlation between COR (Y) and ROM. This is clearly demonstrated by the representative cases shown in Fig. 5.

Under the lubrication of normal saline within the sheath, the superior endplate of the Bryan disc slides along the surface of the biconvex nucleus pulposus with an arc motion trajectory during flexion and extension [33], which simulates the physiological translation. After the implantation of the Bryan disc, the balanced and stable interactions between the surrounding soft tissues and the vertebrae or prosthesis can be restored with the overall biomechanical and kinematic adjustments of the cervical spine. Meanwhile, according to physiological needs, with the cooperation of surrounding soft tissues, the arc sliding (translation) of the superior endplate relative to the inferior endplate of the prosthesis can be adjusted automatically during flexion and extension. Therefore, an appropriate ROM of the operated level was obtained, and the COR was adjusted to the optimal location along the superior–inferior direction, so as to simulate the preoperative ROM and COR.

There are some limitations in this study. First, the location of COR at the level with cervical disc degeneration will change, and the preoperative COR may not represent the physiological COR [45]. Second, our analysis was limited to data collected at two time points: preoperation and the last follow-up. A complete trend of clinical and radiological outcomes over time is not available but should be studied. Third, no correlative factors were identified for COR (X). However, the formula proposed by Bogduk et al. [22] suggests a positive correlation between COR (X) and translation, and the insertion depth of the prosthesis may also affect COR (X) [36]. Larger sample sizes and improved clinical research methods are required to advance the kinematic research of ACDR in the future.

Conclusions

Satisfactory clinical and radiological outcomes for single-level Bryan ACDR were confirmed in this mid-long-term follow-up study. At least 7 years after operation, the COR at the operated level was maintained, probably due to the replication of the physiological interrelations, i.e. COR (Y) is negatively correlated to translation and ROM.

Availability of data and materials

The datasets analyzed during the current study are available from the corresponding author on reasonable request.

Abbreviations

ACDF:

Anterior cervical discectomy and fusion

ACDR:

Artificial cervical disc replacement

ASD:

Adjacent segment degeneration

CDDD:

Cervical degenerative disc disease

COR:

Center of rotation

CR:

Center of reaction

FSU:

Functional spinal unit

ICR:

Instantaneous center of rotation

IROM:

Inferior range of motion

mJOA:

Modified Japanese Orthopedic Association

NDI:

Neck Disability Index

ROM:

Range of motion

SROM:

Superior range of motion

VAS:

Visual analogue scale

References

  1. Findlay C, Ayis S, Demetriades AK. Total disc replacement versus anterior cervical discectomy and fusion: a systematic review with meta-analysis of data from a total of 3160 patients across 14 randomized controlled trials with both short- and medium- to long-term outcomes. Bone Joint J. 2018;100-B(8):991–1001. https://doi.org/10.1302/0301-620X.100B8.BJJ-2018-0120.R1.

    CAS  Article  PubMed  Google Scholar 

  2. Gandhi AA, Kode S, DeVries NA, Grosland NM, Smucker JD, Fredericks DC. Biomechanical analysis of cervical disc replacement and fusion using single level, two level, and hybrid constructs. Spine (Phila Pa 1976). 2015;40(20):1578–85. https://doi.org/10.1097/BRS.0000000000001044.

    Article  Google Scholar 

  3. Powell JW, Sasso RC, Metcalf NH, Anderson PA, Hipp JA. Quality of spinal motion with cervical disk arthroplasty: computer-aided radiographic analysis. J Spinal Disord Tech. 2010;23(2):89–95. https://doi.org/10.1097/BSD.0b013e3181991413.

    Article  PubMed  Google Scholar 

  4. Mo Z, Zhao Y, Du C, Sun Y, Zhang M, Fan Y. Does location of rotation center in artificial disc affect cervical biomechanics? Spine (Phila Pa 1976). 2015;40(8):E469–75. https://doi.org/10.1097/BRS.0000000000000818.

    Article  Google Scholar 

  5. Kelly BP, Zufelt NA, Sander EJ, DiAngelo DJ. The influence of fixed sagittal plane centers of rotation on motion segment mechanics and range of motion in the cervical spine. J Biomech. 2013;46(7):1369–75. https://doi.org/10.1016/j.jbiomech.2013.01.018.

    Article  PubMed  Google Scholar 

  6. Sang H, Cui W, Sang D, Guo Z, Liu B. How center of rotation changes and what affects these after cervical arthroplasty: a systematic review and meta-analysis. World Neurosurg. 2020;135:e702–9. https://doi.org/10.1016/j.wneu.2019.12.111.

    Article  PubMed  Google Scholar 

  7. Guo Z, Cui W, Sang DC, Sang HP, Liu BG. Clinical relevance of cervical kinematic quality parameters in planar movement. Orthop Surg. 2019;11(2):167–75. https://doi.org/10.1111/os.12435.

    Article  PubMed  PubMed Central  Google Scholar 

  8. Hu X, Jiang M, Liu H, Rong X, Hong Y, Ding C, et al. Five-year trends in center of rotation after single-level cervical arthroplasty with the Prestige-LP Disc. World Neurosurg. 2019;132:e941–8. https://doi.org/10.1016/j.wneu.2019.07.042.

    Article  PubMed  Google Scholar 

  9. van Mameren H, Sanches H, Beursgens J, Drukker J. Cervical spine motion in the sagittal plane. II. Position of segmental averaged instantaneous centers of rotation—a cineradiographic study. Spine (Phila Pa 1976). 1992;17(5):467–74. https://doi.org/10.1097/00007632-199205000-00001.

    Article  Google Scholar 

  10. Anderst W, Baillargeon E, Donaldson W, Lee J, Kang J. Motion path of the instant center of rotation in the cervical spine during in vivo dynamic flexion-extension: implications for artificial disc design and evaluation of motion quality after arthrodesis. Spine (Phila Pa 1976). 2013;38(10):E594–601. https://doi.org/10.1097/BRS.0b013e31828ca5c7.

    Article  Google Scholar 

  11. Li Y, Zhang Z, Liao Z, Mo Z, Liu W. Finite element analysis of influence of axial position of center of rotation of a cervical total disc replacement on biomechanical parameters: simulated 2-level replacement based on a validated model. World Neurosurg. 2017;106:932–8. https://doi.org/10.1016/j.wneu.2017.07.079.

    Article  PubMed  Google Scholar 

  12. Lee SW, Draper ER, Hughes SP. Instantaneous center of rotation and instability of the cervical spine. A clinical study. Spine (Phila Pa 1976). 1997;22(6):641–8. https://doi.org/10.1097/00007632-199703150-00013.

    CAS  Article  Google Scholar 

  13. Bogduk N, Mercer S. Biomechanics of the cervical spin. I: normal kinematics. Clin Biomech (Bristol, Avon). 2000;15(9):633–48. https://doi.org/10.1016/s0268-0033(00)00034-6.

    CAS  Article  Google Scholar 

  14. Galbusera F, Fantigrossi A, Raimondi MT, Sassi M, Fornari M, Assietti R. Biomechanics of the C5–C6 spinal unit before and after placement of a disc prosthesis. Biomech Model Mechanobiol. 2006;5(4):253–61. https://doi.org/10.1007/s10237-006-0015-4.

    CAS  Article  PubMed  Google Scholar 

  15. Pickett GE, Rouleau JP, Duggal N. Kinematic analysis of the cervical spine following implantation of an artificial cervical disc. Spine (Phila Pa 1976). 2005;30(17):1949–54. https://doi.org/10.1097/01.brs.0000176320.82079.ce.

    Article  Google Scholar 

  16. Lavelle WF, Riew KD, Levi AD, Florman JE. Ten-year outcomes of cervical disc replacement with the BRYAN cervical disc: results from a prospective, randomized, controlled clinical trial. Spine (Phila Pa 1976). 2019;44(9):601–8. https://doi.org/10.1097/BRS.0000000000002907.

    Article  Google Scholar 

  17. Pointillart V, Castelain JE, Coudert P, Cawley DT, Gille O, Vital JM. Outcomes of the Bryan cervical disc replacement: fifteen year follow-up. Int Orthop. 2018;42(4):851–7. https://doi.org/10.1007/s00264-017-3745-2.

    Article  PubMed  Google Scholar 

  18. Genitiempo M, Perna A, Santagada DA, Meluzio MC, Proietti L, Bocchi MB, et al. Single-level Bryan cervical disc arthroplasty: evaluation of radiological and clinical outcomes after 18 years of follow-up. Eur Spine J. 2020;29(11):2823–30. https://doi.org/10.1007/s00586-020-06486-5.

    Article  PubMed  Google Scholar 

  19. Reitman CA, Mauro KM, Nguyen L, Ziegler JM, Hipp JA. Intervertebral motion between flexion and extension in asymptomatic individuals. Spine (Phila Pa 1976). 2004;29(24):2832–43. https://doi.org/10.1097/01.brs.0000147740.69525.58.

    Article  Google Scholar 

  20. Xu JX, Zhang YZ, Shen Y, Ding WY. Effect of modified techniques in Bryan cervical disc arthroplasty. Spine (Phila Pa 1976). 2009;34(10):1012–7. https://doi.org/10.1097/BRS.0b013e31819c4a5b.

    Article  Google Scholar 

  21. Koller H, Meier O, Zenner J, Mayer M, Hitzl W. In vivo analysis of cervical kinematics after implantation of a minimally constrained cervical artificial disc replacement. Eur Spine J. 2013;22(4):747–58. https://doi.org/10.1007/s00586-012-2583-6.

    Article  PubMed  Google Scholar 

  22. Bogduk N, Amevo B, Pearcy M. A biological basis for instantaneous centres of rotation of the vertebral column. Proc Inst Mech Eng H. 1995;209(3):177–83. https://doi.org/10.1243/PIME_PROC_1995_209_341_02.

    CAS  Article  PubMed  Google Scholar 

  23. Amevo B, Macintosh JE, Worth D, Bogduk N. Instantaneous axes of rotation of the typical cervical motion segments: I. An empirical study of technical errors. Clin Biomech (Bristol, Avon). 1991;6(1):31–7. https://doi.org/10.1016/0268-0033(91)90039-S.

    CAS  Article  Google Scholar 

  24. Liu B, Liu Z, VanHoof T, Kalala J, Zeng Z, Lin X. Kinematic study of the relation between the instantaneous center of rotation and degenerative changes in the cervical intervertebral disc. Eur Spine J. 2014;23(11):2307–13. https://doi.org/10.1007/s00586-014-3431-7.

    Article  PubMed  Google Scholar 

  25. Amevo B, Aprill C, Bogduk N. Abnormal instantaneous axes of rotation in patients with neck pain. Spine (Phila Pa 1976). 1992;17(7):748–56. https://doi.org/10.1097/00007632-199207000-00004.

    CAS  Article  Google Scholar 

  26. Amevo B, Worth D, Bogduk N. Instantaneous axes of rotation of the typical cervical motion segments: II. Optimization of technical errors. Clin Biomech (Bristol, Avon). 1991;6(1):38–46. https://doi.org/10.1016/0268-0033(91)90040-W.

    CAS  Article  Google Scholar 

  27. Amevo B, Worth D, Bogduk N. Instantaneous axes of rotation of the typical cervical motion segments: a study in normal volunteers. Clin Biomech (Bristol, Avon). 1991;6(2):111–7. https://doi.org/10.1016/0268-0033(91)90008-E.

    CAS  Article  Google Scholar 

  28. Johnson JP, Lauryssen C, Cambron HO, Pashman R, Regan JJ, Anand N, et al. Sagittal alignment and the Bryan cervical artificial disc. Neurosurg Focus. 2004;17(6):E14. https://doi.org/10.3171/foc.2004.17.6.14.

    Article  PubMed  Google Scholar 

  29. Yi S, Shin HC, Kim KN, Park HK, Jang IT, Yoon DH. Modified techniques to prevent sagittal imbalance after cervical arthroplasty. Spine (Phila Pa 1976). 2007;32(18):1986–91. https://doi.org/10.1097/BRS.0b013e318133fb99.

    Article  Google Scholar 

  30. Yang YC, Nie L, Cheng L, Hou Y. Clinical and radiographic reports following cervical arthroplasty: a 24-month follow-up. Int Orthop. 2009;33(4):1037–42. https://doi.org/10.1007/s00264-008-0571-6.

    CAS  Article  PubMed  Google Scholar 

  31. 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(6):E6. https://doi.org/10.3171/2010.3.FOCUS1058.

    Article  PubMed  Google Scholar 

  32. Ryu WH, Kowalczyk I, Duggal N. Long-term kinematic analysis of cervical spine after single-level implantation of Bryan cervical disc prosthesis. Spine J. 2013;13(6):628–34. https://doi.org/10.1016/j.spinee.2013.02.046.

    Article  PubMed  Google Scholar 

  33. Galbusera F, Bellini CM, Raimondi MT, Fornari M, Assietti R. Cervical spine biomechanics following implantation of a disc prosthesis. Med Eng Phys. 2008;30(9):1127–33. https://doi.org/10.1016/j.medengphy.2008.02.002.

    Article  PubMed  Google Scholar 

  34. Bryan VJ. Cervical motion segment replacement. Eur Spine J. 2002;11(Suppl 2):S92–7. https://doi.org/10.1007/s00586-002-0437-3.

    Article  PubMed  PubMed Central  Google Scholar 

  35. Lou J, Li H, Rong X, Wu W, Liu H. Location change of center of rotation after single-level cervical total disc replacement with ProDisc-C. Acta Orthop Traumatol Turc. 2016;50(3):339–45. https://doi.org/10.3944/AOTT.2016.15.0182.

    Article  PubMed  Google Scholar 

  36. Duggal N, Bertagnoli R, Rabin D, Wharton N, Kowalczyk I. ProDisc-C: an in vivo kinematic study. J Spinal Disord Tech. 2011;24(5):334–9. https://doi.org/10.1097/BSD.0b013e3181fbf8aa.

    Article  PubMed  Google Scholar 

  37. Kowalczyk I, Lazaro BC, Fink M, Rabin D, Duggal N. Analysis of in vivo kinematics of 3 different cervical devices: Bryan disc, ProDisc-C, and Prestige LP disc. J Neurosurg Spine. 2011;15(6):630–5. https://doi.org/10.3171/2011.8.SPINE11273.

    Article  PubMed  Google Scholar 

  38. Rong X, Gong Q, Liu H, Hong Y, Lou J, Wu W, et al. The effect of deviated center of rotation on flexion-extension range of motion after single-level cervical arthroplasty: an in vivo study. Spine (Phila Pa 1976). 2014;39(26 Spec No.):B12–8. https://doi.org/10.1097/BRS.0000000000000634.

    Article  Google Scholar 

  39. Kowalczyk I, Chaudhary N, Duggal N. Kinematic analysis following implantation of the PRESTIGE LP. Int J Spine Surg. 2013;7:e118–22. https://doi.org/10.1016/j.ijsp.2013.10.003.

    Article  PubMed  PubMed Central  Google Scholar 

  40. 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: cranial versus caudal geometric center. Spine (Phila Pa 1976). 2008;33(1):E6–9. https://doi.org/10.1097/BRS.0b013e31815e5dce.

    Article  Google Scholar 

  41. Milne N. The role of zygapophysial joint orientation and uncinate processes in controlling motion in the cervical spine. J Anat. 1991;178:189–201.

    CAS  PubMed  PubMed Central  Google Scholar 

  42. Penning L. Differences in anatomy, motion, development and aging of the upper and lower cervical disk segments. Clin Biomech (Bristol, Avon). 1988;3(1):37–47. https://doi.org/10.1016/0268-0033(88)90124-6.

    CAS  Article  Google Scholar 

  43. White AR, Panjabi MM. The basic kinematics of the human spine. A review of past and current knowledge. Spine (Phila Pa 1976). 1978;3(1):12–20. https://doi.org/10.1097/00007632-197803000-00003.

    Article  Google Scholar 

  44. Nowitzke A, Westaway M, Bogduk N. Cervical zygapophyseal joints: geometrical parameters and relationship to cervical kinematics. Clin Biomech (Bristol, Avon). 1994;9(6):342–8. https://doi.org/10.1016/0268-0033(94)90063-9.

    CAS  Article  Google Scholar 

  45. Muhlbauer M, Tomasch E, Sinz W, Trattnig S, Steffan H. In cervical arthroplasty, only prosthesis with flexible biomechanical properties should be used for achieving a near-physiological motion pattern. J Orthop Surg Res. 2020;15(1):391. https://doi.org/10.1186/s13018-020-01908-y.

    Article  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We are grateful to those who gave assistance to this study.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author information

Authors and Affiliations

Authors

Contributions

CL and XY made contributions to the conception and design of the study. CL collected, analyzed, and interpreted the follow-up data with the assistance of YX, YY, and HZ. CL drafted the original manuscript and submitted it to XY and FW for review and editing. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Xing Yu.

Ethics declarations

Ethics approval and consent to participate

This study was approved by the Medical Ethics Committee of Dongzhimen Hospital (ethical approval number: 2021DZMEC-082-02) and was conducted in accordance with the Declaration of Helsinki. All patients were informed in advance and voluntarily consented to participate in the study.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Li, C., Yu, X., Xiong, Y. et al. Mid-long-term follow-up of operated level kinematics after single-level artificial cervical disc replacement with Bryan disc. J Orthop Surg Res 17, 149 (2022). https://doi.org/10.1186/s13018-022-03051-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s13018-022-03051-2

Keywords

  • Artificial cervical disc replacement
  • Bryan disc
  • Center of rotation
  • Kinematics
  • Clinical outcomes
  • Radiological outcomes