Multilevel Cervical Disc Replacement Research Articles

Range of motion after 1, 2, and 3 level cervical disc arthroplasty

BackgroundMotion of a solid body involves translation and rotation. Few investigations examine the isolated translational and rotational components associated with disc arthroplasty devices. This study investigates single- and multi-level cervical disc arthroplasty with respect to index and adjacent level range of motion. The investigators hypothesized that single- and multilevel cervical disc replacement will lead to comparable or improved motion at implanted and adjacent levels. MethodsSeven human cervical spines from C2 to C7 were subjected to displacement-controlled loading in flexion, extension, and lateral bending under intact, 1-Level (C5–C6), 2-Level (C5–C6, C6–C7) and 3-Level (C5–C6, C6–C7, C4–C5) conditions. 3D motions sensors were mounted at C4, C5, and C6. Motion data for translations and rotations at each level for each surgical condition and loading mode were compared to intact conditions. Results1-Level: The index surgery resulted in statistically increased translations in extension and lateral bending at all levels with statistically increased translation observed in flexion in the superior and inferior levels. In rotation, the index surgeries decreased rotation under flexion, with remaining levels not statistically different to intact conditions. 2-LevelA device placed inferiorly resulted in statistically increased translations at all levels in extension with statistically increased translations superior and inferior to the index level in flexion. Lateral bending resulted in increased nonsignificant translations. Rotations were elevated or comparable to the intact level for all loading. 3-LevelTranslations were statistically increased for all levels in all loading modes while rotations were elevated or were comparable to the intact level for all loading modes and levels. ConclusionsMicromotion sensors permitted monitoring and recording of small magnitude angulations and translations using a loading mechanism that did not over constrain cervical segmental motion. Multilevel cervical disc arthroplasty yielded comparable or increased overall motion at the index and adjacent levels compared to intact conditions.

81. Do patient expectations represent a more important clinical difference: a study of surgical outcomes in the cervical spine

<h3>BACKGROUND CONTEXT</h3> Minimum clinically important difference (MCID) has been lauded as a more relevant assessment of postoperative outcomes. However, patient expectations have also gained attention as an indicator for patient satisfaction. <h3>PURPOSE</h3> To compare the impact of achieving an MCID or meeting preoperative expectations on patient satisfaction following cervical spine procedures. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort. <h3>PATIENT SAMPLE</h3> Seventy-seven patients undergoing primary or revision, single- or multilevel cervical disc replacement or anterior cervical discectomy and fusion (ACDF). <h3>OUTCOME MEASURES</h3> Demographic and perioperative characteristics, visual analogue scale (VAS) neck and arm. <h3>METHODS</h3> A database was reviewed for patients undergoing primary or revision, single- or multilevel cervical disc replacement or ACDF. Demographic and perioperative characteristics were collected and descriptive statistics were performed. Patients' expectations for postoperative neck and arm pain were assessed preoperatively on a scale from 1-10. Visual analogue scale (VAS) neck and arm pain was assessed at preoperative and postoperative (6-week, 12-weeks, 6-months, 1-year) timepoints. Patient satisfaction regarding their current level of neck and arm pain was recorded at each postoperative timepoint. "Meeting expectations" was defined as postoperative VAS arm and neck scores equaling preoperative expectation scores. Achievement of MCID was determined using the following previously established values: VAS neck ≥ 2.6, VAS arm ≥ 4.1. Linear regression was used to determine if meeting expectations or achieving MCID were predictors of postoperative satisfaction. Differences in effect sizes of expectations met and MCID achievement as predictors of satisfaction were directly compared. <h3>RESULTS</h3> Of 77 patients, the cohort had a mean age of 48.8 years, was 40.3% female and 44.0% obese. Myeloradiculopathy was the most common preoperative spinal diagnosis (88.3%) and a majority of patients underwent ACDF (57.1%). Most procedures took place at a single level, mean operative time was 58.0 minutes and mean blood loss was 28.6 mL. Mean preoperative VAS arm and neck were 4.6 and 3.4, respectively. Mean satisfaction ranged from 6.4-7.5 for arm pain and 6.6-7.5 for neck pain. A majority of patients met expectations for arm pain through 6-months and at 12-weeks and 1-year for neck pain. A majority of patients met MCID for VAS neck through 6-months, but at no timepoints for VAS arm. Meeting expectations for arm and neck pain was a significant predictor of satisfaction at all timepoints except 6-months (all p≤0.003). Achieving MCID significantly predicted postoperative satisfaction at 6-weeks and 12-weeks for arm pain (both p≤0.013) and at 12-weeks and 6-months for neck pain (both p≤0.044). Meeting expectations was a significantly stronger predictor of satisfaction than MCID for both arm and neck pain at 1-year (p=0.007, p=0.012). <h3>CONCLUSIONS</h3> Both MCID achievement and meeting expectations for VAS arm and neck were significant predictors of satisfaction at short-term timepoints. However, meeting expectations was the only significant predictor of satisfaction at 1-year. This suggests patient expectations may be a more valuable metric for assessing patient perceptions of long-term pain improvement following cervical spine procedures. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs

Multimodal Analgesic Management for Cervical Spine Surgery in the Ambulatory Setting.

Patient selection and analgesic techniques, such as the multimodal analgesic (MMA) protocol, aid in ambulatory surgical center (ASC) cervical spine surgery. The purpose of this case series is to characterize patients undergoing anterior cervical discectomy and fusion (ACDF) and total cervical disc replacement (CDR) in an ASC with an enhanced MMA protocol. A prospectively maintained registry was retrospectively reviewed for cervical surgeries between May 2013 and August 2019. Inclusion criteria included ASC patients who underwent single-level or multilevel CDR or ACDF using an MMA protocol. Baseline, intraoperative, and postoperative characteristics were recorded, including length of stay, visual analog scale pain scores, neck disability index, complications, and narcotics administered. A total of 178 patients met inclusion criteria with 125 single-level, 52 two-level, and 1 three-level procedure. Of those patients, 127 underwent ACDF and 51 underwent CDR. The longest procedure was 95 minutes and the mean length of stay was 6.1 hours, with 2 patients requiring hospital admission. All other patients were discharged within 10 hours. One of the admitted patients experienced a postoperative seizure that was later determined to be secondary to drug use and serotonin syndrome. The second patient developed an anterior cervical hematoma 5 hours postoperatively, which was immediately evacuated. The patient was admitted for observation and discharged the next day. In our study, patients experienced considerable improvement in disability scores, with a low likelihood of postoperative complications. A safe and effective MMA protocol may help facilitate anterior cervical surgery in the outpatient setting. 3. Transitioning anterior cervical discectomy and fusions to the ASC requires an appropriate MMA protocol. Our findings reveal that an enhanced MMA protocol will help improve disability scores while keeping the likelihood of postoperative complications low. This supports the ASC setting for cervical spine procedures in appropriate patient populations.

Cervical Disc Replacement: Trends, Costs, and Complications.

Study DesignRetrospective review of insurance database.PurposeTo investigate national trends, complications, and costs after cervical disc replacement (CDR) using an administrative insurance database representative of the United States population.Overview of LiteratureAs CDR continues to be used to treat patients with cervical stenosis, it is important to gain a better understanding of its use on a national level, potential complications, and cost. This information will allow for optimal patient counseling, risk stratification, and healthcare cost assessments. Several prior studies have investigated complications associated with CDR, but they have been limited by small sample size, single institution experiences, limited follow-up, and potential conflicts of interest.MethodsPatients who underwent single or multilevel CDR between 2007 and 2015 were identified using an insurance database. We collected data on annual trends, reimbursement costs, patient demographic information, hospital information, and information on complications from the time of operation to 1 year postoperative.ResultsTotal of 293 patients underwent either single or multilevel CDR. The number of procedures increased nonlinearly over time at an average of 17% per year, with a greater increase seen in the outpatient setting. Less than 3.7% of patients had new onset pain within 1 year after CDR. Within 1 year, 12.3% of patients reported a mechanical and/or bone-related complication. There were no patients who indicated a new nerve injury within 6 months of follow-up. Less than 3.7% of patients presented with dysphagia or dysphonia within 6 months, infection within 3 months, or a revision or reoperation within 1 year. Average reimbursement for single-level inpatient versus outpatient CDR was US $33,696.28 and US $34,675.12, respectively (p=0.29).ConclusionsThis study demonstrated that the use of CDR continued to increase. The most common complication was mechanical and/or bone-related, and cost analysis demonstrated no significant difference between inpatient and outpatient CDR.

Editorial: Cervical arthroplasty

Tu et al.8 present a case of a 67-year-old man who underwent a cervical total disc replacement (ProDisc-C, Synthes) at the C5–6 level for the treatment of cervical spondylosis. Plain radiographs obtained on postoperative Day 3 revealed a vertical split fracture of the C-5 vertebral body. Dynamic radiographs showed no evidence of instability, and the patient did not have neck pain or radicular symptoms. The fracture was managed nonoperatively with a cervical collar for 3 months and subcutaneous injections of teriparatide. A CT scan performed at 2-year follow-up demonstrated that the fracture had healed. This report is of particular interest because this particular complication was not reported in the US investigational device exemption study of ProDisc-C (which appropriately excluded patients with osteoporosis).6 However, this complication has been reported in a case report of multilevel cervical disc replacement with ProDisc-C.3 An area of concern with this case report lies in patient selection. The authors performed a cervical arthroplasty procedure on an elderly patient with extensive cervical spondylosis. In our opinion, the best candidates for cervical arthroplasty are younger patients with good bone quality and no evidence of facet joint arthropathy.1,5 Surgeons should avoid arthroplasty in patients older than 60 years of age who often have significant facet joint spondylosis and osteoporosis in order to avoid the complication presented here. Nonsurgical treatment of the vertebral body fracture worked in this case. However, we would have managed the complication differently. Our approach would have been to remove the implant and convert the case to a fusion. We thank the authors for bringing this rare complication to our attention. This case report emphasizes the need to follow the inclusion and exclusion criteria established in the US FDA arthroplasty trials.2,4–7 Disclosure

Superiority of Multilevel Cervical Arthroplasty Outcomes Versus Single-Level Outcomes

Class 2 level of evidence: This is a prospective, consecutive series of 229 prosthetic implantations that were concurrently enrolled between single-level versus multilevel cervical arthroplasty comprising an FDA Pilot Study. This study investigated multilevel cervical disc replacement in relation to single-level cervical arthroplasty to find if the same reduction in clinical success would occur with this alternative treatment. Usually, the clinical outcomes of instrumented cervical fusions deteriorate as the number of vertebral levels of involvement increases. A total of 229 patients presented with cervical herniated nucleus pulposus, cervical spondylosis, and/or adjacent segment disease with cervical radiculopathy or myelopathy. Following anterior cervical neurologic decompression seventy-one patients required porous coated motion (PCM) cervical arthroplasties from C3-C4 to C7-T1 (Group S, single level). Sixty-nine patients underwent 158 multilevel PCM cervical arthroplasties (Group M, multilevel) during the same time interval, for the same indications, performed by the same surgeons under the same clinical protocol: double level, 53 cases; three levels, 12 cases: and 4 levels, 4 cases. The self-assessment outcomes instruments showed significantly more improvement for the multilevel cases. The mean improvement in the NDI for the single cases was 37.6% versus the multilevel cases mean improvement in NDI was 52.6% (P = 0.021). The difference between the two was statistically significant. The mean improvement in the VAS showed the same association: single-level mean improvement 58.4% versus the multilevel cases mean VAS improvement was 65.9%. The Odom's were also more improved for the multilevel versus the single-level group: 93.9% versus 90.5% in the excellent, good, and fair categories. The reoperation rates and serious adverse events were similar between the single-level (S = 3) to the multilevel arthroplasty (M = 2) groups. Kaplan-Meier implant survivorship analysis at 3 years for the cohort of 229 prostheses was 94.5% (confidence interval, 1.00-0.820). This prospective study of cervical arthroplasty is the first report to date showing significantly improved clinical outcomes for multilevel cervical arthroplasty compared with single-level cervical disc replacement using an FDA validated outcome instrument.

Sagittal Split Fractures in Multilevel Cervical Arthroplasty Using a Keeled Prosthesis

This is a case report of intraoperative sagittal split fractures in multilevel cervical disc replacement using a keeled prosthesis. The patient's clinical course is discussed and outcomes measured with the SF-36 questionnaire, oswestry disability index, and visual analog scale neck pain are compared with the other patients at our institution that have undergone multilevel disc replacement. The patient did well and has not had any complications related to the device used or fractures. The risks and techniques to avoid this complication when using a keeled prosthesis are discussed in detail.

5:02 28. Is The Motion “Normal” After Multi-Level Cervical Disc Replacement? – Analysis of Motion at Each Treated and Adjacent Levels 1 to 3-Level Disc Replacement versus Fusion

BACKGROUND CONTEXT: Large-scale clinical trials have shown the efficacy of lumbar disc replacement (DR) in restoring or maintaining range of motion (ROM). One of the purported advantages of disc replacement is the prevention of accelerated adjacent segment degeneration by preserving natural motion at the treated and untreated adjacent level(s). However, well-designed comparisons of ROM across disc replacements (especially at individual segments in multi-level arthroplasty) and untreated adjacent levels have not been reported and compared against fusion (anterior cervical discectomy and fusion, ACDF).