Outcomes Of Cervical Disc Replacement Research Articles

Association of Craniocervical Sagittal Alignment With the Outcomes of Cervical Disc Replacement.

Retrospective cohort study. To explore the association between craniocervical sagittal balance and clinical and radiological outcomes of cervical disc replacement (CDR). Patients who underwent 1-level and 2-level CDR were retrospectively analyzed. Clinical outcomes were evaluated using scores on the Japanese Orthopaedic Association (JOA), Visual Analogue Scale (VAS), and Neck Disability Index (NDI). The craniocervical sagittal alignment parameters, including the C0-C2 Cobb angle, C2-C7 Cobb angle, C2 slope, T1 slope, C2-C7 sagittal vertical axis (SVA), C1-C7 SVA, the center of gravity of the head (CGH)-C7 SVA, and range of motion (ROM) at the surgical segments were measured. A total of 169 patients were involved. Significantly lower pre- and postoperative C2 slope and CGH-C7 SVA were found in arthroplasty levels with better ROMs. Patients with a higher preoperative C2 slope and CGH-C7 SVA had lower cervical lordosis and ROM after surgery. There were no significant differences in the clinical outcomes between patients with different sagittal balance statuses. C2-C7 SVA and CGH-C7 SVA were significantly associated with radiographic adjacent segment pathology (rASP). Craniocervical sagittal balance is associated with cervical lordosis and ROM at the index level after CDR. A higher preoperative SVA is related to the presence and progression of rASP. A relationship between sagittal alignment and clinical outcomes was not observed.

Outcomes of cervical disc replacement in patients with neck pain greater than arm pain

BACKGROUND CONTEXTAlthough anterior cervical discectomy and fusion is believed to positively impact a patient's radicular symptoms as well as axial neck pain, the outcomes of cervical disc replacement (CDR) with regards to neck pain specifically have not been established. PURPOSEPrimary: to assess clinical improvement following CDR in patients with neck pain greater than arm pain. Secondary: to compare the clinical outcomes between patients undergoing CDR for predominant neck pain (pNP), predominant arm pain (pAP), and equal neck and arm pain (ENAP). STUDY DESIGNRetrospective review of prospectively collected data. PATIENT SAMPLEPatients who had undergone one- or two-level CDR for the treatment of degenerative cervical pathology and had a minimum of 6-month follow-up were included and stratified into three cohorts based on their predominant location of pain: pNP, pAP, and ENAP. OUTCOME MEASURESPatient-reported outcomes: Neck Disability Index (NDI), Visual Analog Scale (VAS) neck and arm, Short Form 12-Item Physical Health Score (SF12-PHS), Short Form 12-Item Mental Health Score (SF12-MHS), minimal clinically important difference (MCID). METHODSChanges in Patient-reported outcomes from preoperative values to early (<6 months) and late (≥6 months) postoperative timepoints were analyzed within each of the three groups. The percentage of patients achieving MCID was also evaluated. RESULTSOne hundred twenty-five patients (52 pNP, 30 pAP, 43 ENAP) were included. The pNP cohort demonstrated significant improvements in early and late NDI and VAS-Neck, early SF-12 MCS, and late SF-12 PCS. The pAP and ENAP cohorts demonstrated significant improvements in all PROMs, including NDI, VAS-Neck, VAS-Arm, SF-12 PCS, and SF-12 MCS, at both the early and late timepoints. No statistically significant differences were found in the MCID achievement rates for NDI, VAS-Neck, SF-12 PCS, and SF-12 MCS at the late timepoint amongst the three groups. CONCLUSIONSCDR leads to comparable improvement in neck pain and disability in patients presenting with neck pain greater than arm pain and meeting specific clinical and radiographic criteria.

Anterior Cervical Discectomy and Fusion Versus Cervical Disc Replacement in Patients With Significant Cervical Spondylosis.

Retrospective cohort study. The aim was to compare clinical outcomes in patients with significant cervical spondylosis treated with cervical disc replacement (CDR) compared with anterior cervical discectomy and fusion (ACDF). As CDR utilization has increased over the past decade, recent studies have investigated the outcomes of CDR in patients with more significant spondylotic changes and demonstrated improved postoperative patient-reported outcomes (PROs). However, no prior study has investigated clinical outcomes of patients with significant spondylotic changes treated with CDR in comparison to ACDF. Patients who underwent 1-level or 2-level CDR or ACDF with significant cervical spondylosis, quantified using a validated grading scale, were identified, and prospectively collected data was retrospectively reviewed. The following PROs were analyzed: Neck Disability Index (NDI), visual analog scale-Neck, visual analog scale-Arm, and PROMIS Physical Function (PROMIS-PF) Computer Adaptive Test Score. Demographic, operative, and radiographic variables, and achievement of minimum clinically important difference (MCID) for each PRO were compared between the 2 groups. A total of 66 patients were included in the present study, of which 35 (53%) were treated with CDR and 31 (47%) with ACDF. The preoperative cervical spondylotic grade was similar between the 2 groups (1.8 vs. 2.2, P=0.27). At final follow-up, there was no significant difference in the absolute value for each PRO between the 2 groups (P>0.19) and both groups demonstrated significant improvement in each PRO compared with preoperative values (P<0.01). There was no significant difference in the percentage of patients achieving the MCID for each PRO when comparing CDR to ACDF (P>0.09). A similar percentage of patients with significant degenerative cervical spondylosis achieved the MCID across multiple PROs when treated with CDR or ACDF. Patients in both treatment groups demonstrated significant improvement in all PROs assessed when compared with preoperative values. Level III.

Comparison of Clinical and Imaging Outcomes of Cervical Disc Replacement in Patients with Different Hounsfield Units

To compare clinical and imaging outcomes after cervical disc replacement (CDR) in patients with different Hounsfield units (HU). We performed a retrospective study of patients with cervical degenerative disc disease treated by 1-level and 2-level Prestige-LP arthroplasty. The patients were divided into group A (HU <320), group B (HU 320-347), and group C (HU >347) according to the results of cervical vertebral HU measurement in the literature, and the clinical and radiographic results were compared among the 3 groups. A total of 127 patients were reviewed, comprising 13 patients in group A, 31 patients in group B, and 83 patients in group C. The clinical parameters were significantly improved postoperatively in the 3 groups (P < 0.05). However, no significant differences were found among the 3 groups at the final follow-up (P > 0.05). The mean postoperative intervertebral space height (ISH) was 4.76 ± 0.45 mm, 5.23 ± 0.81 mm, and 6.26 ± 1.12 mm in the 3 groups, respectively. The postoperative ISH in group C was significantly higher than those in the other groups at the final follow-up (P < 0.001). One patient in group A and 1 patient in group B had implant subsidence, and degeneration at the inferiorly adjacent level was radiographically identified in 30.77% patients in group A, 16.13% patients in group B, and 9.64% patients in group C. However, there were only significant differences between group A and group C in subsidence (P= 0.011) and occurrence of adjacent level degeneration (P= 0.032). The HU value has a large variation range among the patients with T-score ≥ -2.5. We found significantly increased rates of implant subsidence, loss of ISH, and adjacent segment degeneration in patients with lower HU value undergoing CDR. However, these radiographic complications did not predispose patients with lower HU value to worse clinical outcomes. Routine application of HU combined with dual-energy X-ray absorptiometry measurement to evaluate bone quality may help to screen the optimal candidates for CDR and reduce the implant-related complications.

Reply to Commentary on "Impact of Nonlordotic Sagittal Alignment on Short-term Outcomes of Cervical Disc Replacement".

Reply to Commentary on "Impact of Nonlordotic Sagittal Alignment on Short-term Outcomes of Cervical Disc Replacement".

Commentary on "Impact of Nonlordotic Sagittal Alignment on Short-term Outcomes of Cervical Disc Replacement".

Commentary on "Impact of Nonlordotic Sagittal Alignment on Short-term Outcomes of Cervical Disc Replacement".

Impact of Nonlordotic Sagittal Alignment on Short-term Outcomes of Cervical Disc Replacement

ObjectiveTo evaluate outcomes of cervical disc replacement (CDR) in patients with nonlordotic alignment. MethodsPatients who underwent CDR were retrospectively reviewed and divided into 3 cohorts: (1) neutral/lordotic segmental and C2–7 Cobb angle (L), (2) nonlordotic segmental Cobb angle, lordotic C2–7 Cobb angle (NL-S), and (3) nonlordotic segmental and C2–7 Cobb angle (NL-SC). Radiographic and patient-reported outcomes (PROMs) were compared. ResultsOne-hundred five patients were included (L: 37, NL-S: 30, NL-SC: 38). A significant gain in segmental lordosis was seen in all cohorts at < 6 months (L: -1.90° [p = 0.007]; NL-S: -5.16° [p < 0.0001]; NL-SC: -6.00° [p < 0.0001]) and ≥ 6 months (L: -2.07° [p = 0.031; NL-S: -6.04° [p < 0.0001]; NL-SC: -6.74° [p < 0.0001]), with greater lordosis generated in preoperatively nonlordotic cohorts (p < 0.0001). C2–7 lordosis improved in the preoperatively nonlordotic cohort (NL-SC: 8.04°) at follow-up of < 6 months (-4.15°, p=0.003) and ≥ 6 months (-6.40°, p=0.003), but not enough to create lordotic alignment (< 6 months: 3.89°; ≥ 6 months: 4.06°). All cohorts showed improvement in Neck Disability Index, visual analogue scale (VAS) neck, and VAS arm, without significant difference among groups in the amount of improvement (≥ 6-month PROMs follow-up=69%). ConclusionIn patients without major kyphotic deformity, CDR has the potential to generate and maintain lordosis and improve PROMs in the short-term, and can be an effective treatment option for patients with nonlordotic alignment.

P106. Impact of predominant preoperative symptoms on outcomes of CDR

BACKGROUND CONTEXT Cervical pathologies can commonly present with both neck and radicular symptoms. Cervical disc replacement (CDR) is typically indicated in the treatment of radicular symptoms, though it has also been shown to improve neck pain. Its efficacy has yet to be studied between patients presenting with primarily neck, arm, or equivalent neck and arm pain. PURPOSE To assess whether predominant preoperative symptom has an impact on outcomes of CDR. STUDY DESIGN/SETTING Retrospective review of prospectively collected data. PATIENT SAMPLE A total of 107 patients who had undergone CDR by three surgeons at a single academic institution. OUTCOME MEASURES PROMs (NDI, neck/arm VAS, SF-12 PCS/MCS) were collected prospectively as standard of care preoperatively and at each follow-up (2wk, 6wk, 12wk, and 6mo). METHODS Based on predominant symptom, patients were divided into three groups: NECK (VAS Neck>VAS Arm,n=41), ARM (VAS Arm>VAS Neck,n=28), and NA (VAS Neck=VAS Arm,n=38). Differences in postoperative PROMs and change in PROMs from the preoperative time-point were compared using t-tests. RESULTS Compared to the ARM cohort (4.61±2.82), NECK (6.73±2.48; p=0.005) and NA (6.69±2.85;p=0.007) patients had significantly worse preoperative neck VAS scores, which is not unexpected as groups were created based on preoperative VAS. Although all three groups demonstrated significant improvement in neck VAS by 2wks, which was maintained until 6mo, NECK patients had significantly worse neck VAS than ARM patients at 2 weeks (p=0.020), 12 weeks (p=0.002), and 6 months (p=0.003), with no differences in the amount of improvement among the three groups at any time point. Compared to the NECK cohort (3.28±2.85), ARM (7.45±2.02; p CONCLUSIONS All three cohorts demonstrated significant improvement in NDI and neck VAS with no differences in the degree of improvement. All groups demonstrated improvement in arm VAS, with greater and earlier improvement seen in ARM and NA compared to NECK. All groups demonstrated improvements in PCS and MCS scores, with greater and earlier PCS improvement seen in ARM and earlier MCS improvement seen in NA. Overall, all groups showed improvement following CDR; however, the improvement in ARM and NA is greater and seen earlier compared to NECK. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Two-level cervical disc replacement: perspectives and patient selection

Two-level cervical disc replacement: perspectives and patient selection Ankur S Narain,&nbsp;Fady Y Hijji,&nbsp;Daniel D Bohl,&nbsp;Kelly H Yom,&nbsp;Krishna T Kudaravalli,&nbsp;Kern Singh Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA Introduction: Cervical disc replacement (CDR) is an emerging treatment option for cervical degenerative disease. Postulated benefits of cervical disc replacement compared to anterior cervical discectomy and fusion include preserved motion at the operative segments and decreased motion at adjacent levels. Multiple studies have been performed investigating the outcomes of CDR in single-level pathology. The investigation of the use of CDR in two-level pathology is an emerging topic within the literature.Purpose: To critically evaluate the literature regarding two-level CDR in order to determine its utility compared to two-level cervical arthrodesis. Patient selection factors including indications and contraindications will also be explored.Methods: The PubMed database was searched for all articles published on the subject of two-level CDR up until October 2016. Studies were classified by publication year, study design, sample size, follow-up interval, and conflict of interest. Outcomes were recorded from each study, and included data on patient-reported outcomes, radiographic measurements, range of motion, peri- and postoperative complications, heterotopic ossification, adjacent segment disease, reoperation rate, and total intervention cost. Results: Fourteen studies were included in this review. All studies demonstrated at least noninferiority of two-level CDR compared to both two-level arthrodesis and single-level CDR. Patient selection in two-level CDR is driven by the inclusion and exclusion criteria presented in prospective, randomized controlled trials. The most common indication is subaxial degenerative disc disease over two contiguous levels presenting with radiculopathy or myelopathy. Furthermore, costs analyses trended toward at least noninferiority of two-level CDR.Conclusion: Two-level CDR is noninferior to two-level anterior cervical discectomy and fusion in terms of both outcomes and costs. While a few studies suggested superiority of two-level CDR, the presence of significant conflicts of interest by the study authors may introduce bias. Further prospective, randomized trials without conflicts of interest are necessary to determine if two-level CDR demonstrates truly superior outcomes. Keywords: cervical disc replacement, anterior cervical discectomy and fusion, two-level, patient selection, outcomes, conflict of interest

Long-Term Results after Cervical Disc Replacement using Bryan Prosthesis

Study Design Retrospective clinical study. Objective To study the outcome of cervical disc replacement with a Bryan prosthesis in 60 to 91 months follow-up duration through analyzing the motion of index segments and associated heterotopic ossification (HO), and adjacent segment degeneration using their motion, patient satisfaction, and pain as indicators. Summary of Background Data Cervical disc replacement is considered to be equivalent if not superior to discectomy and fusion because it allows for decompression while maintaining segmental motion and has the potential to minimize adjacent segment disease. However, long-term results of motion and degeneration of adjacent segments after cervical disc replacement are rare. Methods Data of 47 patients with cervical disc prolapse, treated with cervical disc replacement with a Bryan disc between January 28, 2002 and October 31, 2003 in the orthopädische Klinik Markröningen, Germany were analyzed. Cobb angles of the exchanged segment, and the adjacent segments were measured on pre- and postoperative radiographic pictures. The grade of heterotopic ossification was examined. The postoperational functionality of the cervical spine was examined via active range of motion. Patients' satisfaction and pain were assessed using; the neck disability index (NDI), Odom criteria, and visual analog scale (VAS). Results At follow-up no postoperative complications or revision were recorded. No HO formation was present in 34 patients (72.3%), grade I and grade III HO was present in 10 patients (21.3%) five of each grade. Segmental fusion (grade IV) was observed in three patients (6.4%). Most patients showed improved motion and high satisfaction. Mean NDI was 12.3% (SD = 13.12). Mean VAS score was 1.8 (SD = 2.1). Using Odom criteria all patients were classified as a clinical success. Conclusions Preserving stability (as a nonresorbable stable place holder) and the goals of decompression, cervical disc replacement preserved motion, and decreased related degeneration clinically and radiologically.

Comparison of Cervical Motor Function between Artificial Cervical Disc Replacement with Prodisc-C and Anterior Cervical Discectomy and Fusion for the Treatment of Cervical Spondylotic Myelopathy

Introduction The objective of this study was to compare outcomes of cervical disc replacement (ACDR) using Prodisc-C (Synthes, Inc.) and anterior cervical discectomy and fusion (ACDF) in patients with symptomatic cervical spondylotic myelopathy. Materials and Methods A total of 40 patients with radiologically confirmed symptomatic cervical spondylotic myelopathy were enrolled between March 2008 and August 2011 into prospective ongoing study and received ACDR ( N = 20) or ACDF ( N = 20) at discretion of operating surgeon. Patients were followed up at pre-specified intervals at 1, 3, 6, 12, and 24 months postoperative. Follow-up evaluations consisted of visual analogue scale (VAS) for neck and arm pain intensity, Neck Disability Index (NDI), and radiologic evaluations of intervertebral disc height, cervical curvature, total cervical range of motion, and segment contribution to total cervical range of motion (ROM). Results Both groups improved in VAS and NDI scores after surgery. The NDI score improved ( p &lt; 0.01) from 34.06 preoperative to 16.81 at 24 months in the ACDR group and from 35.60 preoperatively to 17.28 at 24 months in the ACDF group. The difference between the groups was not significant. The VAS for neck and arm pain intensity showed better outcomes in ACDR than in ACDG group at 6 months follow-up ( p &lt; 0.05). This difference disappeared at 24 months follow-up. The disk height at the index level increased in both groups postoperatively. There were no changes in disk height at the first cephalic and caudal levels in either group at any follow-up. The total cervical range of motion (ROM) improved at all follow-up evaluations in the ACDR group ( p &lt; 0.05). There were no changes in overall ROM in the ACDF group (Fig. 1). The overall ROM was higher at 24 months in ACDR compared with ACDF (49.93 ± 11.91 and 41.11 ± 9.80, respectively, p &lt; 0.05). Conclusion ACDR and ACDF are effective in improving functional outcomes in subjects with symptomatic cervical spondylotic myelopathy. Range of motion outcomes are superior in ACDR compared with ACDF. Disclosure of Interest Q. Zhou: Conflict with AO International, Southwest Hospital D. Chen: None declared B. Kopjar: Conflict with AO Foundation, Smith &amp; Nephew, Cerapedics R. Shi: None declared J. Xu: None declared F. Luo: None declared F. Dai: None declared Q. He: None declared H. Li: None declared

Clinical and radiographic outcomes of cervical disc replacement with a new prosthesis

Background contextAnterior cervical discectomy and interbody fusion was a classical treatment for cervical degenerative disc disease (CDDD). However, the rigid fusion also leads to a reduction in normal cervical spine motion and to increased biomechanical stress at adjacent levels, which in turn accelerates degenerative changes of the discs at these levels. Cervical disc replacement (CDR) is a new technology with the aim of addressing the limitations of fusion procession and preserving motion at the treated level. Discover prosthesis (DePuy Spine, Raynham, MA, USA) is a new type artificial disc and there are few reports about it. PurposeThe purpose of this study was to analyze the primary clinical and radiographic outcomes of CDR with Discover prosthesis to treat mono- or bi-segment CDDD in a Chinese population. Study designThe study design was prospective and single-center clinical trial of the Discover prosthesis in the treatment of patients with mono- or bi-segment CDDD. Patients sampleSeventy-nine patients with 102 Discover prosthesis arthroplasty performed (56 mono-segment and 23 bi-segment) were evaluated. Outcome measuresClinical outcomes based on Japanese Orthopaedic Association (JOA), visual analog scale (VAS) pain score, and Odom's scale and radiographic outcomes including the anterior disc heights (ADH), posterior disc heights (PDH), range of motion, and performance of heterotopic ossification (HO) of the operative segment were assessed. MethodsClinical and radiographic follow-up was performed. Preoperative and postoperative ADH, PDH, and range of motion were measured from lateral and flexion-extension radiographs. The paired t test was used to assess the difference of clinical and radiographic outcomes before and after operation. The performance of HO was observed by two independent MD. ResultsThe mean follow-up time for all the patients was 31.6 months, ranging from 24 to 43 months. Mean preoperative JOA score was 9.5, and VAS overall pain score was 7.2. At 2-, 6-, 12-, and 24-month follow-up, the mean JOA score was 14.1, 14.7, 15.3, and 14.9, whereas the mean VAS overall pain score was 1.9, 1.7, 1.8, and 1.4, respectively. Mean JOA and VAS scores showed statistical improvements in the postoperative period. Seven patients had mild dysphagia within the first month after operation. According to Odom's scale, 52 patients had excellent outcomes, 25 patients had good outcomes, and 2 patients had fair outcomes at 2-year follow-up. The Mean preoperative ADH and PDH of the operative segment were 4.9 mm and 3.1 mm. Compared with preoperative, there were significantly increased and maintenance well at 2- (7.5 mm, 5.1 mm), 6- (7.5 mm, 5.0 mm), 12- (7.4 mm, 4.9 mm) and 24-month (7.2 mm, 5.0 mm) follow-up. Range of motion of the operative segment in the postoperative follow-up was slightly increased than the preoperative follow-up but not statistically significant. Heterotopic ossification was presented in six replaced levels at 1-year follow-up including 4 Grade I and 2 Grade II and 18 replaced levels at the follow-up more than 2 years including 8 grade I and 10 grade II. No prosthesis subsidence or excursion was identified. ConclusionsThe use of Discover prostheses in our study resulted in satisfactory clinical and radiographic outcomes. The prostheses can restore and maintain interbody height, while preserve the motion of the treated segment. Although the results of this study demonstrate initial safety and effectiveness in a Chinese population, we need further studies to know more about the impact of CDR with Discover prosthesis, especially on HO and adjacent segment degeneration.

Cervical Disc Replacement: A Systematic Review of Medline Indexed Literature

Anterior Cervical Discectomy and Fusion (ACDF) currently remains as the gold standard treatment for cervical disc herniation and Degenerative Disc Disease (DDD) refractory to conservative management. Even though anterior cervical fusion provides excellent clinical results, it has been implicated in abnormal kinematic strain on adjacent disc level resulting in symptomatic adjacent segment disease. Anterior cervical disc replacement (ACDR) is an alternative procedure to anterior cervical discectomy and fusion. The aims of cervical disc replacement were to preserve the motion at the index level and to protect the adjacent levels from accelerated symptomatic degeneration. The aim of this systematic review was to evaluate the outcomes of cervical disc replacement published in MEDLINE indexed literature. A literature search was carried out in medical electronic database MEDLINE. Keywords used for the search were Cervical vertebrae, Cervical spine, Neck, Intervertebral disc, Total disc replacement, Arthroplasty, Replacement, Treatment outcome. Two authors reviewed titles and abstracts of all two hundred and thirty six hits. The articles that satisfied the inclusion criteria were critically appraised while remaining articles were discarded. Anterior cervical disc replacement is a relatively new technology in spinal surgery. There are several short and intermediate term follow-up studies to prove the safety and efficacy of ACDR with satisfactory clinical and radiological outcomes. More intermediate to long-term follow-up studies are needed to prove the safety and efficacy of ACDR.

Long-term clinical and radiographic outcomes of cervical disc replacement with the Prestige disc: results from a prospective randomized controlled clinical trial

The purpose of this study was to determine long-term clinical outcomes in patients undergoing anterior cervical surgery in which a cervical disc prosthesis was used to treat single-level degenerative cervical disc disease. In this prospective, nonblinded study, 541 patients at 32 investigational sites were randomly assigned to 1 of 2 treatment groups. The results of the investigational group, in which patients received the Prestige disc prosthesis, were compared with those of the control group, in which patients underwent an instrumented interbody fusion. Data were collected preoperatively, intraoperatively, and at 1.5, 3, 6, 12, 24, 36, and 60 months postoperatively. To date, 271 patients have completed 5 years of clinical follow-up (144 investigational and 127 control patients). Significant improvements in Neck Disability Index (NDI) scores, Physical Component Summary scores of the 36-Item Short-Form Health Survey, and neck and arm pain scores were achieved by 1.5 months in both groups and sustained at 5 years. The mean NDI improvements from preoperative scores were 35.4, 36.3, and 38.4 at 24, 36, and 60 months, respectively, in the investigational group. The corresponding mean NDI improvements were 33.9, 31.3, and 34.1 in the control group. The intergroup differences at both 36 and 60 months were significant (p = 0.008 and 0.022, respectively). The overall rates of maintenance or improvement in neurological status in the investigational group were 91.6%, 92.8%, and 95.0%, respectively, at 24, 36, and 60 months compared with 83.6%, 83.2%, and 88.9% in the control group (p = 0.006, 0.004, and 0.051, respectively). The implant effectively maintained angular motion, averaging more than 7.3 degrees at 36 months and 6.5 degrees at 60 months after surgery. No implant migration was observed up to 60 months. There were statistically significant differences between the investigational and control groups with regard to the rate of revision and supplemental fixation surgical procedures performed subsequent to the index procedure. Additional surgical procedures for adjacent-segment disease were observed in both treatment groups. Rates for surgery at adjacent levels trended lower in the investigational group (8 patients [11 surgeries]) compared with those in the control group (13 patients [16 surgeries]), but the differences were not statistically significant (p = 0.376). Some of the second surgeries involved both index and adjacent levels. The Prestige disc maintains improved clinical outcomes and segmental motion after implantation at 5-year follow-up.

Clinical outcome of cervical disc replacement in the treatment of cervical spondylotic myelopathy

Objective To study the effect of cervical disc replacement in the treatment of cervical spondylotic myelopathy(CSM).Methods 21 patients with CSM(17 cases of spondylotic myelopathy,2 cases of radiculopathy and 2 cases of acute soft disc herniation)were treated by anterior decompression and replaced by the Bryan cervical disc prosthesis. Results All cases were: followed for 4～12 months, average 8 months. The pre-operative JOA score was 8.5 and post-operative score was 15.5 on average. There were no prosthesis, curve was good. Replaced segment achieved stability and restored partial of normal ROM. There was no subsidence of implant and no worsening of pre-operative symptoms, post-operative 21 cases remained flexion/extension movement at replaced segments at latest follow up. There was no neck stiffness and restriction of movement complained by the patients. Conclusion The Bryan cervical disc replacement for the treatment of CSM has offered an excellent early clinical outcome. Key words: Spinal Diseases; Surgical procedures; Operative

Cervical Disc Replacement in Patients With and Without Previous Adjacent Level Fusion Surgery

Prospective 6-center study. OBJECTIVE.: To evaluate outcomes of cervical disc replacement performed adjacent to a prior cervical fusion. The use of disc replacement adjacent to a prior anterior cervical decompression and fusion (ACDF) is an attractive reconstructive option, obviating the need for a multilevel fusion. This study reports outcomes from patients with and without previous ACDF receiving the porous coated motion (PCM) artificial cervical disc in a United States Federal Drug Administration Investigational Device Exemption trials. Patients between ages of 18 and 65 with single-level cervical radiculopathy and/or myelopathy, unresponsive to at least 6 weeks of nonsurgical therapy, or experiencing progressive neurologic symptoms were enrolled. Clinical outcomes are compared for patients receiving a PCM disc at a level adjacent to a prior ACDF ("adjacent") and those without having previously had fusion ("primary"). 126 PCM patients were primary (mean age: 44.4 years.) and 26 patients had previous "adjacent level" fusion surgery (mean age: 46.4 years). Surgery time was similar in both groups (96 minutes and 98 minutes, respectively; P = 0.761), and mean blood loss was 76 mL and 66 mL in the 2 groups, respectively (P = 0.491). Clinical outcomes using Neck Disability Index and Visual Analog Scores neck and arm scores showed significant improvement after surgery and were similar between groups at all time points. Revision surgery occurred in 2 of 126 primary patients, and in 2 of 26 patients in the adjacent-to-fusion group. Although the level adjacent to a prior cervical fusion is subject to increased biomechanical forces, potentially leading to a higher risk of failure, the PCM disc was well tolerated in the short term. The early clinical results of disc replacement adjacent to a prior fusion are good and comparable to the outcomes after primary disc replacement surgery. However, in view of the small study population and short-term follow-up, continued study is mandatory.

Artificial Disc Versus Fusion

A total of 115 patients were randomized in a 1:1 ratio to a Bryan artificial disc replacement (56) or an anterior cervical fusion with allograft and a plate (59). The purpose of this study is to examine the functional outcome and radiographic results of this prospective, randomized trial to determine the role of the Bryan artificial cervical disc replacement for patients with 1-level cervical disc disease. Artificial cervical disc replacement has become an option for cervical radiculopathy. Previous studies have evaluated the efficacy of this alternative without the scientific rigor of a concurrent control population. This study is a pooled data set from 3 centers involved in the U.S. FDA Investigational Device Exemption trial evaluating the Bryan artificial cervical disc. The purpose of this study is to examine the functional outcome and radiographic results of this prospective, randomized trial to determine the role of the Bryan artificial cervical disc replacement for patients with 1-level cervical disc disease; 12-month follow-up is available for 110 patients and 24 month follow-up complete for 99 patients. There are 30 males and 26 females in the Bryan group and 32 males and 27 females in the fusion group. The average age was 43 years (Bryan) and 46 years (fusion). Disability and pain were assessed using the Neck Disability Index (NDI) and the Visual Analog Scale (VAS) of the neck and of the arm pain. SF-36 outcome measures were obtained including the physical component as well as the mental component scores. Range of motion was determined by independent radiologic assessment of flexion-extension radiographs. We report a prospective, randomized study comparing the functional outcome of cervical disc replacement to an anterior cervical fusion with results of 99 patients at 2 years. Prospective data were collected before surgery and at 6 weeks, 3, 6, 12, and 24 months after surgery. The average operative time for the control group was 1.1 hours and the Bryan Group 1.7 hours. Average blood loss was 49 mL (control) and 64 mL (Bryan). Average hospital stay was 0.6 days (control) and 0.9 days (Bryan). The mean NDI before surgery was not statistically different between groups: 47 (Bryan) and 49 (control). Twelve-month follow-up NDI is 10 (Bryan) and 18 (control) (P = 0.013). At 2-year follow-up, NDI for the Bryan group is 11 and the control group is 20 (P = 0.005). The mean arm pain VAS before surgery was 70 (Bryan) and 71 (control). At 1-year follow-up, Bryan arm pain VAS was 12 and control 23 (P = 0.031). At 2-year follow-up, the average arm pain VAS for the Bryan group was 14 and control 28 (P = 0.014). The mean neck pain VAS before surgery was 72 (Bryan) and 73 (control). One-year follow-up scores were 17 (Bryan) and 28 (control) (P = 0.05). At 2 years: 16 (Bryan) and 32 (control) (P = 0.005). SF-36 scores: Physical component--Before surgery Bryan 34 and control 32. At 24 months: Bryan 51 and control 46 (P = 0.009). More motion was retained after surgery in the disc replacement group than the plated group at the index level (P < 0.006 at 3, 6, 12, and 24 months). The disc replacement group retained an average of 7.9 degrees of flexion-extension at 24 months. In contrast, the average range of motion in the fusion group was 0.6 degrees at 24 months. There were 6 additional operations in this series: 4 in the control group and 2 in the investigational group. There were no intraoperative complications, no vascular or neurologic complications, no spontaneous fusions, and no device failures or explantations in the Bryan cohort. The Bryan artificial disc replacement compares favorably to anterior cervical discectomy and fusion for the treatment of patients with 1-level cervical disc disease. At the 2-year follow-up, there are statistically significant differences between the groups with improvements in the NDI, the neck pain and arm pain VAS scores, and the SF-36 physical component score in the Bryan disc population.