ProDisc–C versus anterior cervical discectomy and fusion for the surgical treatment of symptomatic cervical disc disease: two-year outcomes of Asian prospective randomized controlled multicentre study

European Spine Journal - Our study aimed to evaluate non-inferiority of ProDisc-C to anterior cervical discectomy and fusion (ACDF) in terms of clinical outcomes and incidence of adjacent segment...     

Is the likelihood of dysphagia different in patients undergoing one-level versus two-level anterior cervical discectomy and fusion?

BACKGROUND CONTEXTDysphagia following anterior cervical discectomy and fusion (ACDF) is a common complication, the etiology of which has not been established. Given that one potential mechanism for dysphagia is local tissue edema, it is thought that a greater number of operative levels may result in higher dysphagia rates. However, prior reports comparing one-level to two-level ACDF have shown varying results.PURPOSETo determine if there is a difference in dysphagia between one-level and two-level ACDF.STUDY DESIGN/SETTINGRetrospective review of prospectively collected data.PATIENT SAMPLEPatients who underwent one- or two-level ACDF with a plate-graft construct by a single-surgeon at a high-volume academic medical center.OUTCOME MEASURESNeck Disability Index, Visual Analog Scale for neck pain and arm pain, Short Form-12 physical and mental health components, and Swallowing Quality of Life (SWAL-QOL) Questionnaire.METHODSPatient demographics, operative data, and patient-reported outcome measures (PROMs; Neck Disability Index, Visual Analog Scale, Short Form-12, and SWAL-QOL) of patients undergoing one- and two-level ACDF were compared using Fisher exact test for categorical variables and Student's t test for continuous variables. Regression analyses were conducted to identify factors associated with 6- and 12-week SWAL-QOL scores in order to determine whether the number of surgical levels impacts these outcomes.RESULTSFifty-eight patients (22 one-level and 36 two-level ACDF) were included. Patients undergoing two-level fusions were older (54.17+8.67 vs 48.06+10.68 years, p=.02) and had longer operative times (69.08+10.51 vs 53.5+14.35 minutes, p<.0001). There were no other significant differences in demographics or operative data. Both groups showed a statistically significant improvement in PROMs from preoperatively to 12 weeks. There was no difference in PROMs or dysphagia rates between groups at any time-point. Younger age (p=.023), male sex (p=.021), longer operative times (p=.068), and worse preoperative SWAL-QOL (p<.0001) were associated with dysphagia at 6 weeks. Preoperative SWAL-QOL was the only variable associated with dysphagia at 12 weeks (p=.003). Operative time of >61.5 minutes had a sensitivity and specificity of 62.1% for worse dysphagia scores at 6 weeks compared with baseline.CONCLUSIONSThe results of our study indicate that there is no difference in the degree of postoperative dysphagia in one- versus two-level ACDF. However, other variables associated with increased postoperative dysphagia in our population included younger age, male sex, procedural time >61.5 minutes, and worse preoperative dysphagia. Larger studies are required to confirm these findings and identify additional risk factors for postoperative dysphagia.     

Management of cranio-cervical injuries: C1–C2 posterior cervical fusion and decompression

The occipitocervical junction allows for rotation and flexion-extension of the head rotation. Bony articulations between C1–C2 and the ligamentous complex are responsible for stability. Fractures or injuries to the ligamentous complex often requires operative management in order to restore stability. In this review, techniques for posterior cervical fusion and decompression are reviewed and include: fixation to C2, transarticular screw construct, screw-rod construct, occipital-cervical fusion, and posterior wiring. Complications and outcomes for each of the posterior techniques are described. While the primary focus is posterior approaches, anterior C1–C2 approach play a critical role in managing these injuries and is described briefly.     

What is the role of dynamic cervical spine radiographs in predicting pseudarthrosis revision following anterior cervical discectomy and fusion?

Background ContextPostoperative dynamic radiographs are used to assess fusion status after anterior cervical discectomy and fusion (ACDF) with comparable accuracy to computed tomography (CT) scans.PurposeTo (1) determine if dynamic radiographs accurately predict pseudarthrosis revision in a cohort of largely asymptomatic patients who underwent ACDF, (2) determine how adjacent segment motion is affected by fusion status, and (3) analyze how clinical outcomes differ between patients with symptomatic and asymptomatic pseudarthrosis.Study DesignRetrospective cohort study.Patient SamplePatients ≥ 18 years who underwent primary one- to four-level ACDF at a single institution over a 10-year period.Outcome MeasuresInterspinous motion on preoperative and postoperative flexion-extension radiographs and preoperative and postoperative Visual Analogue Scale for Neck Pain (VAS Neck) and Arm Pain (VAS Arm), Neck Disability Index (NDI), Modified Japanese Orthopaedic Association scale (mJOA), Mental and Physical Component Scores of the Short-Form 12 (SF-12) Health Survey (MCS-12 and PCS-12)MethodsThe difference in spinous process motion between flexion and extension radiographs was used to determine motion at each level of the ACDF construct. Pseudarthrosis was defined as ≥ 1 mm spinous process motion on dynamic radiographs. A receiver operating characteristic (ROC) curve was generated to predict the probability of surgical revision for pseudarthrosis based on millimeters of interspinous motion at each instrumented level. Patient reported outcome measures (PROMs) were used to assess the effect of pseudarthrosis on clinical outcomes. Alpha was set at p<.05.ResultsA total of 597 patients met inclusion criteria including 1,203 ACDF levels. Of those, 215 patients (36.0%) were diagnosed with a pseudarthrosis on dynamic radiographs with 29 patients (4.9%) requiring pseudarthrosis revision. ROC analysis identified a “cutoff” value of 1.00 mm of interspinous process motion for generating an optimal area under the curve (AUC). The negative predictive value (NPV) was 99.6%, whereas the positive predictive value (PPV) was 13.7%. When analyzing adjacent segment motion, the Δ supra-adjacent interspinous process motion (ISM) was significantly lower for patients with a superior construct pseudarthrosis (-1.06 mm vs. 1.80 mm, p<.001), whereas the Δ infra-adjacent level ISM was significantly lower for patients with an inferior construct pseudarthrosis (-1.21 mm vs. 2.15 mm, p<.001). Patients with a pseudarthrosis not requiring revision had worse postoperative NDI (29.3 vs. 23.4, p=.027), VAS Neck (3.40 vs. 2.63, p=.012), and VAS Arm (3.09 vs. 1.85, p=.001) scores at 3 months, but not 1-year, compared with patients who were fused. Patients requiring pseudarthrosis revision had higher 1-year postoperative NDI (38.0 vs. 23.7, p=.047) and lower 1-year postoperative Δ VAS Arm (-0.22 vs. -2.97, p=.016) scores.ConclusionsOne-year postoperative dynamic radiographs have a greater than 99% negative predictive value for identifying patients requiring pseudarthrosis revision, but they have a low positive predictive value. Most patients with a pseudarthrosis remain asymptomatic with similar 1-year postoperative patient-reported outcomes compared with patients without a pseudarthrosis.     

Surgical treatment for osteoporotic vertebral collapse with neurological deficits: Retrospective comparative study of three procedures—anterior surgery versus posterior spinal shorting osteotomy versus posterior spinal fusion using vertebroplasty

Purpose

In general, osteoporotic vertebral collapse (OVC) with neurological deficits requires sufficient decompression of neural tissues to restore function level in activities of daily living (ADL). However, it remains unclear as to which procedure provides better neurological recovery. The primary purpose of this study was to compare neurological recovery among three typical procedures for OVC with neurological deficits. Secondary purpose was to compare postoperative ADL function.

Methods

We retrospectively reviewed data for 88 patients (29 men and 59 women) with OVC and neurological deficits who underwent surgery. Three typical kinds of surgical procedures with different decompression methods were used: (1) anterior direct neural decompression and reconstruction (AR group: 27 patients), (2) posterior spinal shorting osteotomy with direct neural decompression (PS group: 36 patients), and (3) posterior indirect neural decompression and short-segment spinal fusion combined with vertebroplasty (VP group: 25 patients). We examined clinical results regarding neurological deficits and function level in ADL and radiological results.

Results

The mean improvement rates for neurological deficits and ADL function level were 60.1 and 55.0 %, respectively. There were no significant differences among three groups in improvement rates for neurological deficits or ADL function level. The VP group had a significantly lower estimated mean blood loss (338 mL) and mean duration of surgery (229 min) than both the AR and PS groups (p < 0.001).

Conclusion

Direct neural decompression is not always necessary, and the majority of patients can be treated with a less-invasive procedure such as short-segment posterior spinal fusion with indirect decompression combined with vertebroplasty. The high-priority issue is careful evaluation of patients’ general health and osteoporosis severity, so that the surgeon can choose the procedure best suited for each patient.     

Clinical outcome following anterior cervical discectomy and fusion with and without anterior cervical plating for the treatment of cervical disc herniation—a 25-year follow-up study

Extreme long-term clinical outcome studies following anterior cervical discectomy and fusion (ACDF) with an autologous iliac crest with and without Caspar plating (ACDF + CP) for the treatment of radiculopathy caused by cervical disc herniation (CDH) are extremely rare. Hospital records of patients who underwent ACDF or ACDF + CP for the treatment of CDH at least 17 years ago were reviewed. Information about diagnosis, surgery, pre- and postoperative clinical process, and repeated procedure was analyzed. At final follow-up, patients were reviewed with a standardized questionnaire including the current neurological status, Neck Disability Index (NDI), Odom’s criteria, a modified EQ-5D, and limitations in quality of life. One hundred twenty-two patients with a mean follow-up of 25 years were evaluated. ACDF was performed in 80 and ACDF + CP in 42 patients, respectively. At final follow-up, 81.1% of patients were free of radicular pain and had no repeated procedure. According to Odom’s criteria, 86.1% of good to excellent functional recovery was noted. The mean NDI and EQ-5D was 14% and 5 points, respectively. There was no significant difference in the assessed clinical outcome parameters between patients treated with ACDF and ACDF + CP. The rate for repeated procedure due to degenerative cervical disorders was 10.7 and 7.4% due to symptomatic adjacent segment disease with 25 years. ACDF and ACDF + CP achieved a high rate radicular pain relief (89.3%) and clinical success (86.1%) for the treatment of CDH within a 25 years follow-up. No statistical difference concerning clinical outcome and rate of repeated procedure was detected.     

One-step (standard) versus two-step surgical approach in adolescent idiopathic scoliosis posterior spinal fusion: Which is better?

Study design

A retrospective cohort study with IRB approval.

Introduction

Significant blood loss remains an important concern in terms of the performance of the posterior spinal fusion in adolescent idiopathic scoliosis. Several strategies have been reported to minimize blood loss during surgery. In order to address the need to minimize blood loss without sacrificing the quality of the fusion, in our hospital, we adopted a two-step surgical approach. This surgical approach consist of the exposure and instrumentation of the lumbar region prior to and followed by an extension of the surgical incision to the thoracic region for its subsequent instrumentation. The main purpose of this study was to compare a two-step surgical approach with the one-step (standard) approach.

Methods

This study was a review of all the data on consecutive posterior spinal fusion surgeries performed by a specific two-surgeon team during 2004–2013. Demographics, surgical variables, radiographic findings, and outcomes regarding blood loss, morbidity, and the duration of the procedure were evaluated.

Results

Eighty-five patients underwent the standard surgical exposure, and 41 patients underwent the two-step surgical technique. With the exception of BMI, neither group showed any statistically preoperative variable significant differences. None of the postoperative outcome variables were statistically significant between both surgical approaches.

Conclusions

No differences were detected in terms of using a two-step surgical approach versus the one-step standard surgical approach regarding perioperative blood loss, surgical time, or complications.

Level of evidence

Level of evidence III.

     

Favourable outcome of posterior decompression and stabilization in lordosis for cervical spondylotic myelopathy: the spinal cord “back shift” concept

Purpose

Surgical management of patients with multilevel CSM aims to decompress the spinal cord and restore the normal sagittal alignment. The literature lacks of high level evidences about the best surgical approach. Posterior decompression and stabilization in lordosis allows spinal cord back shift, leading to indirect decompression of the anterior spinal cord. The purpose of this study was to investigate the efficacy of posterior decompression and stabilization in lordosis for multilevel CSM.

Methods

36 out of 40 patients were clinically assessed at a mean follow-up of 5, 7 years. Outcome measures included EMS, mJOA Score, NDI and SF-12. Patients were asked whether surgery met their expectations and if they would undergo the same surgery again. Bone graft fusion, instrumental failure and cervical curvature were evaluated. Spinal cord back shift was measured and correlation with EMS and mJOA score recovery rate was analyzed.

Results

All scores showed a significative improvement (p < 0.001), except the SF12-MCS (p > 0.05). Ninety percent of patients would undergo the same surgery again. There was no deterioration of the cervical alignment, posterior grafted bones had completely fused and there were no instrument failures. The mean spinal cord back shift was 3.9 mm (range 2.5–4.5 mm). EMS and mJOA recovery rates were significantly correlated with the postoperative posterior cord migration (P < 0.05).

Conclusions

Posterior decompression and stabilization in lordosis is a valuable procedure for patients affected by multilevel CSM, leading to significant clinical improvement thanks to the spinal cord back shift. Postoperative lordotic alignment of the cervical spine is a key factor for successful treatment.

     

Cage-screw and anterior plating combination reduces the risk of micromotion and subsidence in multilevel anterior cervical discectomy and fusion—a finite element study

BACKGROUND CONTEXTAnterior cervical discectomy and fusion (ACDF) is widely used to treat patients with spinal disorders, where the cage is a critical component to achieve satisfactory fusion results. However, it is still not clear whether a cage with screws or without screws will be the best choice for long-term fusion as the micromotion (sliding distance) and subsidence (penetration) of the cage still take place repeatedly.PURPOSEThis study aims to examine the effect of cage-screws on the biomechanical characteristics of the human spine, implanted cage, and associate hardware by comparing the micromotion and subsidence.STUDY DESIGNA finite element (FE) analysis study.METHODSA FE model of a C3-C5 cervical spine with ACDF was developed. The spinal segment was modeled with the removal of the anterior longitudinal ligament (ALL), posterior longitudinal ligament (PLL), and discectomy was then implanted with a cage-screw system. Three models were analyzed: the first was the original spine (S1 model), the second, S2, was implanted with cages and anterior plating, and the third, S3, was implanted with a cage-screw system in addition to the anterior plate. All investigations were under 1 N?m in flexion, extension, lateral bending, and axial rotation situations.RESULTSFinite element analysis (FEA) demonstrated that range of motion (ROM) at C3-C4 in the S2 model was significantly reduced more than that in the S3 model, while the ROM at both C4-C5 in the S3 model was reduced more than that in the S2 model in all simulations. The ROM at C3-C5 in the S1 model was reduced by over 5° in the S2 and S3 models in all loading conditions. The micromotion and subsidence at all contacts of C3-C5 in the S3 model were lower than that in the S2 model in all flexion, extension, bending, and axial simulations. The subsidence and micromotion could be seen in the barrier area of the S2 model, while they occurred near the edge of the screw in the S3 model.CONCLUSIONSThese results showed that the cage-screw and anterior plating combination has promising potential to reduce the risk of micromotion and subsidence of implanted cages in two or more level ACDFs.CLINICAL SIGNIFICANCEThe use of double segmental fixation with cage-screw anterior plating combination constructs may increase the stiffness of the construct and reduce the incidence of clinical and radiographic pseudarthrosis following multilevel ACDF, which in turn, could decrease the need for revision surgeries or supplemental posterior fixation.     

The efficacy assessment of the treatment of degenerative lumbar scoliosis combined with spinal stenosis with posterior ＂responsibility segment＂ decompression and instrumented fusion

Objective： To evaluate the efficacy of the decompression of posterior responsibility segment and the corrective fixation for DLSS. Methods： This is a retrospective review of the charts and radiographs of 79 patients with DLSS treated by posterior responsibility segment decompression and instrumented fusion. The upper instrumented vertebra was T12 in 30 cases and L1 in 49 cases. The lowest instrumented vertebra was L5 in 51 cases and S1 in 28 cases. The Visual Analogue Scale, Japanese Orthopaedic Association, was -29 score. The radiographical measurements and demographic data were reviewed before operation, 1 year after operation and at follow-up. Results： The mean follow-up time was 4.9 years （range, 3～7 years）. Compared with the pre-op data, postoperative JOA score and VAS score as well as Cobb＇s angle were improved significantly （P〈0.05）. 5 cases （6.3%, 5/79） suffered from adjacent segment disease, including junctional kyphosis in 2 cases and progression of disc wedging in 3 cases, without compression fractures or spinal restenosis. In 3 patients, 6 months after surgery, the bilateral S1 pedicle screw was loosed, and L5/S1 facet joints was unfused. Conclusion： For DLSS, the confirmation of ＂responsibility segment＂ is most important, and instrumented fusion at TI2 or L1 could not increase adjacent segment disease significantly and can get a satisfactory effect.