Reoperation Rates Following Open-Door Cervical Laminoplasty.

BACKGROUND: Laminoplasty is a safe and effective procedure for multilevel degenerative cervical stenosis causing myelopathy, that allows for motion preservation. The purpose of this study was to determine the reoperation rate and associated risk factors after cervical laminoplasty. METHODS: We present a retrospective consecutive series of patients who underwent a laminoplasty procedure between January 1, 2005, and October 31, 2012, and had a minimum 2-year follow-up. Demographic data were collected and operative records were reviewed to determine the cervical levels involved in the laminoplasty procedure, any concomitant procedures, and estimated blood loss. Clinical records were reviewed and telephone interviews were conducted on those patients with less than 2-year in-person follow-up. Patients requiring reoperations and the reason for the reoperations were determined, as well as the incidence of postoperative C5 palsy. RESULTS: A total of 222 of 266 patients (83%) with a minimum 2-year follow-up had an average follow-up of 4.97 years. Overall, 26 patients underwent 30 reoperations (13.5%). A total of 15 patients underwent 16 reoperations (7.2%) in the acute postoperative period for infection requiring at least 1 irrigation and debridement, hardware-related issues, or posterior cervical wound issues. A total of 13 patients had 14 reoperations (6.3%) outside of the acute postoperative period for the development of a new radiculopathy, recurrent myelopathy, neurologic symptoms with a kyphotic deformity, or a posttraumatic focal kyphotic deformity. Patients who had a concomitant laminectomy demonstrated a significantly (P = .03) higher reoperation rate than those who did not. There were no other statistically significant associations. The C5 palsy rate was 8.1% (18 of 222). CONCLUSIONS: Although the preserved motion following laminoplasty may allow for the development of new neurologic symptoms, the reoperation rate continues to compare favorably with laminectomy and fusion and remains a reasonable option for the surgical management of multilevel cervical stenosis causing myelopathy. LEVEL OF EVIDENCE: 4.

Adjacent segment degeneration following ProDisc-C total disc replacement (TDR) and anterior cervical discectomy and fusion (ACDF): does surgeon bias effect radiographic interpretation?

PURPOSE: Many investigators have reported the financial conflicts of interest (COI), which could result in potential bias in the reporting of outcomes for patients undergoing total disc replacement (TDR) rather than anterior cervical discectomy and fusion (ACDF). This bias may be subconsciously introduced by the investigator in a non-blinded radiographic review. The purpose of this study was to determine if bias was present when a group of spine specialists rated adjacent segment degeneration (ASD) following cervical TDR or ACDF. METHODS: Potential bias in the assessment of ASD was evaluated through the reviews of cervical radiographs (pre- and 6 years post-operative) from patients participating in the ProDisc-C FDA trial (ProDisc-C IDE #G030059). The index level was blinded on all radiographs during the first review, but unblinded in the second. Five reviewers (a radiologist, two non-TDR surgeons, and two TDR surgeons), two of whom had a COI with the ProDisc-C trial sponsor, assessed ASD on a three point scale: yes, no, or unable to assess. Intra- and inter-rater reliabilities between all raters were assessed by the Kappa statistic. RESULTS: The intra-rater reliability between reviews was substantial, indicating little to no bias in assessing ASD development/progression. The Kappa statistics were 0.580 and 0.644 for the TDR surgeons (p < 0.0001), 0.718 and 0.572 for the non-TDR surgeons (p < 0.0001), and 0.642 for the radiologist (p < 0.0001). Inter-rater reliability for the blinded review ranged from 0.316 to 0.607 (p < 0.0001) and from 0.221 to 0.644 (p < 0.0001) for the unblinded review. CONCLUSIONS: The knowledge of the surgical procedure performed did not bias the assessment of ASD.

The Prediction and Prevention of Dysphagia After Occipitospinal Fusion by Use of the S-line (Swallowing Line).

STUDY DESIGN: Clinical case series and risk factor analysis of dysphagia after occipitospinal fusion (OSF). OBJECTIVE: The aim of this study was to develop new criteria to avoid postoperative dysphagia by analyzing the relationship among the craniocervical alignment, the oropharyngeal space, and the incidence of dysphagia after OSF. SUMMARY OF BACKGROUND DATA: Craniocervical malalignment after OSF is considered to be one of the primary triggers of postoperative dysphagia. However, ideal craniocervical alignment has not been confirmed. METHODS: Thirty-eight patients were included. We measured the O-C2 angle (O-C2A) and the pharyngeal inlet angle (PIA) on the lateral cervical radiogram at follow-up. PIA is defined as the angle between McGregor's line and the line that links the center of the C1 anterior arch and the apex of cervical sagittal curvature. The impact of these two parameters on the diameter of pharyngeal airway space (PAS) and the incidence of the dysphagia were analyzed. RESULTS: Six of 38 cases (15.8%) exhibited the dysphagia. A multiple regression analysis showed that PIA was significantly correlated with PAS (ß = 0.714, P = 0.005). Receiver-operating characteristic curves showed that PIA had a high accuracy as a predictor of the dysphagia with an AUC (area under the curve) of 0.90. Cases with a PIA less than 90 degrees showed significantly higher incidence of dysphagia (31.6%) than those with a 90 or more degrees of PIA (0.0%) (P = 0.008). CONCLUSION: Our results indicated that PIA had the high possibility to predict postoperative dysphagia by OSF with the condition of PIA <90°. Based on these results, we defined "Swallowing-line (S-line)" for the reference of 90° of PIA. S-line (-) is defined as PIA <90°, where the apex of cervical lordosis protruded anterior to the "S-line," which should indicate the patient is at a risk of postoperative dysphagia. LEVEL OF EVIDENCE: 4.

A RCT comparing 7-year clinical outcomes of one level symptomatic cervical disc disease (SCDD) following ProDisc-C total disc arthroplasty (TDA) versus anterior cervical discectomy and fusion (ACDF).

PURPOSE: The objective of this trial was to compare the safety and efficacy of TDA using the ProDisc-C implant to ACDF in patients with single-level SCDD between C3 and C7. METHODS: We report on the single-site results from a larger multicenter trial of 13 sites using an approved US Food and Drug Administration protocol (prospective, randomized controlled non-inferiority design). Patients were randomized one-to-one to either the ProDisc-C device or ACDF. All enrollees were evaluated pre- and post-operatively at regular intervals through month 84. Visual Analog Scale (VAS) for neck and arm pain/intensity, Neck Disability Index (NDI), Short-Form 36 (SF-36), and satisfaction were assessed. RESULTS: Twenty-two patients were randomized to each arm of the study. Nineteen additional patients received the ProDisc-C via continued access. NDI improved with the ProDisc-C more than with ACDF. Total range of motion was maintained with the ProDisc-C, but diminished with ACDF. Neck and arm pain improved more in the ProDisc-C than ACDF group. Patient satisfaction remained higher in the ProDisc-C group at 7 years. SF-36 scores were higher in the TDA group than ACDF group at 7 years; the difference was not clinically significant. Six additional operations (two at the same level; four at an adjacent level) were performed in the ACDF, but none in the ProDisc-C group. CONCLUSIONS: The ProDisc-C implant appears to be safe and effective for the treatment of SCDD. Patients with the implant retained motion at the involved segment and had a lower reoperation rate than those with an ACDF.

ProDisc-C Total Disc Replacement Versus Anterior Cervical Discectomy and Fusion for Single-Level Symptomatic Cervical Disc Disease: Seven-Year Follow-up of the Prospective Randomized U.S. Food and Drug Administration Investigational Device Exemption Study.

BACKGROUND: In patients with single-level cervical degenerative disc disease, total disc arthroplasty can relieve radicular pain and preserve functional motion between two vertebrae. We compared the efficacy and safety of cervical total disc arthroplasty with that of anterior cervical discectomy and fusion (ACDF) for the treatment of single-level cervical degenerative disc disease between C3-C4 and C6-C7. METHODS: Two hundred and nine patients at thirteen sites were randomly treated with either total disc arthroplasty with ProDisc-C (n = 103) or with ACDF (n = 106). Patients were assessed preoperatively; at six weeks and three, six, twelve, eighteen, and twenty-four months postoperatively; and then annually until seven years postoperatively. Outcome measures included the Neck Disability Index (NDI), the Short Form-36 (SF-36), postoperative neurologic parameters, secondary surgical procedures, adverse events, neck and arm pain, and satisfaction scores. RESULTS: At seven years, the overall follow-up rate was 92% (152 of 165). There were no significant differences in demographic factors, follow-up rate, or patient-reported outcomes between groups. Both procedures were effective in reducing neck and arm pain and improving and maintaining function and health-related quality of life. Neurologic status was improved or maintained in 88% and 89% of the patients in the ProDisc-C and ACDF groups, respectively. After seven years of follow-up, thirty secondary surgical procedures had been performed in nineteen (18%) of 106 patients in the ACDF group compared with seven secondary surgical procedures in seven (7%) of 103 patients in the ProDisc-C group (p = 0.0099). There were no significant differences in the rates of any device-related adverse events between the groups. CONCLUSIONS: Total disc arthroplasty with ProDisc-C is a safe and effective surgical treatment of single-level symptomatic cervical degenerative disc disease. Clinical outcomes after total disc arthroplasty with ProDisc-C were similar to those after ACDF. Patients treated with ProDisc-C had a lower probability of subsequent surgery, suggesting that total disc arthroplasty provides durable results and has the potential to slow the rate of adjacent-level disease. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Unintended durotomy in lumbar degenerative spinal surgery: a 10-year systematic review of the literature.

OBJECT Unintended durotomy is a common occurrence during lumbar spinal surgery, particularly in surgery for degenerative spinal conditions, with the reported incidence rate ranging from 0.3% to 35%. The authors performed a systematic literature review on unintended lumbar spine durotomy, specifically aiming to identify the incidence of durotomy during spinal surgery for lumbar degenerative conditions. In addition, the authors analyzed the incidence of durotomy when minimally invasive surgical approaches were used as compared with that following a traditional midline open approach. METHODS A MEDLINE search using the term "lumbar durotomy" (under the 2015 medical subject heading [MeSH] "cerebrospinal fluid leak") was conducted on May 13, 2015, for English-language medical literature published in the period from January 1, 2005, to May 13, 2015. The resulting papers were categorized into 3 groups: 1) those that evaluated unintended durotomy rates during open-approach lumbar spinal surgery, 2) those that evaluated unintended durotomy rates during minimally invasive spine surgery (MISS), and 3) those that evaluated durotomy rates in comparable cohorts undergoing MISS versus open-approach lumbar procedures for similar lumbar pathology. RESULTS The MEDLINE search yielded 116 results. A review of titles produced 22 potentially relevant studies that described open surgical procedures. After a thorough review of individual papers, 19 studies (comprising 15,965 patients) pertaining to durotomy rates during open-approach lumbar surgery were included for analysis. Using the Oxford Centre for Evidence-Based Medicine (CEBM) ranking criteria, there were 7 Level 3 prospective studies and 12 Level 4 retrospective studies. In addition, the authors also included 6 studies (with a total of 1334 patients) that detailed rates of durotomy during minimally invasive surgery for lumbar degenerative disease. In the MISS analysis, there were 2 prospective and 4 retrospective studies. Finally, the authors included 5 studies (with a total of 1364 patients) that directly compared durotomy rates during open-approach versus minimally invasive procedures. Studies of open-approach surgery for lumbar degenerative disease reported a total of 1031 durotomies across all procedures, for an overall durotomy rate of 8.11% (range 2%-20%). Prospectively designed studies reported a higher rate of durotomy than retrospective studies (9.57% vs 4.32%, p = 0.05). Selected MISS studies reported a total of 93 durotomies for a combined durotomy rate of 6.78%. In studies of matched cohorts comparing open-approach surgery with MISS, the durotomy rates were 7.20% (34 durotomies) and 7.02% (68), respectively, which were not significantly different. CONCLUSIONS Spinal surgery for lumbar degenerative disease carries a significant rate of unintended durotomy, regardless of the surgical approach selected by the surgeon. Interpretation of unintended durotomy rates for lumbar surgery is limited by a lack of prospective and cohort-matched controlled studies.

Timing of surgery in thoracolumbar trauma: is early intervention safe?

The understanding of the optimal surgical timing for stabilization in thoracolumbar fractures is severely limited. Thoracolumbar spine fractures can be devastating injuries and are often associated with significant morbidity and mortality. The role of early surgical stabilization (within 48-72 hours of injury) as a vehicle to improve outcomes in these patients has generated significant interest. Goals of early stabilization include improved neurological recovery, faster pulmonary recovery, improved pain control, and decreased health care costs. Opponents cite the potential for increased bleeding, hypotension, and the risk of further cord injury as a few factors that weigh against early stabilization. The concept of spinal cord injury and its relationship to surgical timing remains in question. However, when neurological outcomes are eliminated from the equation, certain measures have shown positive influences from prompt surgical fixation. Early fixation of thoracolumbar spine fractures can significantly decrease the duration of hospital stay and the number of days in the intensive care unit. Additionally, prompt stabilization can reduce rates of pulmonary complications. This includes decreased rates of pneumonia and fewer days on ventilator support. Cost analysis revealed as much as $80,000 in savings per patient with early stabilization. All of these benefits come without an increase in morbidity or evidence of increased mortality. In addition, there is no evidence that early stabilization has any ill effect on the injured or uninjured spinal cord. Based on the existing data, early fixation of thoracolumbar fractures has been linked with positive outcomes without clear evidence of negative impacts on the patient's neurological status, associated morbidities, or mortality. These procedures can be viewed as "damage control" and may consist of simple posterior instrumentation or open reductions with internal fixation as indicated. Based on the current literature it is advisable to proceed with early surgical stabilization of thoracolumbar fractures in a well-resuscitated patient, unless extenuating medical conditions would prevent it.

Dural tears in spine surgery.

Dural tears are among the most commonly seen complications in spine surgery. Most studies in the literature indicate that long-term outcomes are not negatively affected, provided that the tears are diagnosed early and managed appropriately. Direct suture repair remains the preferred method for the management of durotomy caused by or found during surgery. However, recent literature reports encouraging results with sutureless repair. Understanding dural anatomy, dural healing, and cerebrospinal fluid dynamics is helpful in choosing among the available management options for dural tear.

Two-Year Results of a Randomized Controlled Clinical Trial Comparing ProDisc-C and Anterior Cervical Discectomy and Fusion.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is a well-accepted procedure for the treatment of cervical radiculopathy. Hilibrand et al. reported that adjacent segment disease is known to occur at a rate of 2.9% per year after cervical fusion. Developers of cervical disc replacements postulate that maintaining more normal motion may reduce the rate of adjacent segment disease. The purpose of this study was to compare the 2-year efficacy and safety of ACDF and cervical total disc replacement surgery. METHODS: Eighty-seven patients from 2 sites of this 13 multicenter trial were randomized to treatment with either ACDF or cervical disc replacement surgery with the ProDisc-C (Synthes, Inc., West Chester, Pennsylvania) implant. Patient outcomes were assessed via neck disability index (NDI), visual analog pain scale (VAS), and health survey SF-36 (QualityMetric, Lincoln, Rhode Island). Forty-three patients were treated with ACDF using allograft and plating, and 44 were treated with cervical disc replacement. The average age was 44 (23 to 61) years. All surgical procedures were single level. RESULTS: At all measured time points, both groups showed statistically significant improvement over their preoperative baseline with regard to NDI, VAS arm and neck pain levels, SF-36 mental composite score (MCS), and physical composite score (PCS) (P < .05). At 24 months, the disc replacement group showed results equivalent to the ACDF group with regard to NDI, VAS arm and neck pain, and SF-36 MCS. At 24 months, the disc replacement group showed significantly greater improvement in SF- 36 PCS as compared to the ACDF group (P = .0359). Of note, there was a trend toward greater patient satisfaction in the disc replacement group as compared to the ACDF group (83% versus 71%, P = .144). CONCLUSIONS: This study indicates that the tested disc replacement device achieves 2-year results ranging from equivalent to superior in comparison to ACDF in the treatment of symptomatic cervical disc disease. Long-term maintenance of these results has not yet been determined.

Anatomic mapping and evaluation of the esophagus in relation to the cervical vertebral body.

The relationship of the esophagus to the cervical vertebral body (CVB), disc space and longus colli (LC) muscles, to our knowledge, has not been previously studied. The purpose of this study was to quantify the relationship of the esophagus to the CVB, disc space and LC. 30 patients were selected for a retrospective review of computed tomography (CT) scans. Measurements between the esophagus and the C5, C6, and C7 vertebral bodies as well as the C5/6 and C6/7 disc spaces were performed in the midline, 3 mm right and left of midline, and at the edge of the LC on both sides. The closest distance of the esophagus to the CVB and disc space occurs at the midline (range 1.02-1.31 mm at each level). The furthest distance occurred at the edge of the right LC (range 2.67-3.30 mm at each level). The mean distance from the edge of the right LC to the midline was significantly greater (P < 0.01) than mean distance from the edge of the left LC to the midline. No statistical significant differences were observed when comparing measurements at the individual vertebral bodies and disc spaces. The results of the study demonstrate that the esophagus lies in closest proximity to the CVB and disc space in the midline. A larger potential space exists between the esophagus and the CVB and disc space at the edge of the LC. These results may provide insight into a potential cause of post-operative dysphagia. Furthermore, it may help guide the future design of cervical plates to better utilize the potential space between the esophagus and the CVB and disc space at the edge of the LC.

Adjacent segment disc pressures following two-level cervical disc replacement versus simulated anterior cervical fusion.

Anterior cervical fusion (ACF) has been shown to alter the biomechanics of adjacent segments of the cervical spine. The goal of total disc replacement is to address pathology at a given disc with minimal disruption of the operated or adjacent segments. This study compares the pressure within discs adjacent to either a two-level simulated ACDF or a two-level total disc replacement with the ProDisc-C. A special automated motion testing apparatus was constructed. Four fresh cadaveric cervical spine specimens were affixed to the test stand and tested in flexion and extension under specific loads. Intradiscal, miniature strain-gauge-based transducers were placed in the discs above and below the "treated" levels. The specimens were then tested in flexion and extension. Pressure and overall angular displacement were measured. In the most extreme and highest quality specimen the difference at C3/C4 registered 800 kPa and the difference at C6/C7 registered 50 kPa. This same quality specimen treated with the ProDisc reached a flexion angle at much lower moments, 24.3 degrees at 5 N-m, when compared to the the SACF 12.2 degrees at 8.6 N-m. Therefore, the moment needed to achieve 15 degrees of flexion with the SACF treatment was 5.5 N-m and the ProDisc treatment was only 2.9 N-m. This initial data would indicate that adjacent level discs experience substantially lower pressure after two-level disc replacement when compared to two-level SACF. Additional testing to further support these observations is ongoing.

Recurrent transverse myelitis after lumbar spine surgery: a case report.

STUDY DESIGN: A case of recurrent idiopathic transverse myelitis occurring after surgery is reported. OBJECTIVES: To present a case of idiopathic transverse myelitis recurring after surgery and to heighten awareness for the diagnosis and management of this disorder. SUMMARY AND BACKGROUND DATA: Transverse myelitis presenting with acute spinal pain and neurologic deficit must be considered along with structural causes of myelopathy by the spine specialist. This intramedullary spinal cord disorder may be caused by parainfectious and postvaccinal sequelae, multiple sclerosis, spinal cord ischemia, autoimmune disorders, and paraneoplastic syndromes. These various etiologies are often difficult to differentiate. However, a patient's history, clinical course, MRI studies, and laboratory findings often allow such classification. Determination of etiology provides pertinent information regarding potential recurrence, treatment, and prognosis. METHODS: The patient history, physical examination, radiologic and laboratory studies, and pertinent literature were reviewed. RESULTS: Thoracolumbar myelitis developed in the reported patient 6 weeks after lumbar spine surgery during an otherwise uncomplicated postoperative recovery. The workup did not identify a specific cause, and the patient recovered to ambulatory status. However, 4 months after surgery, acute transverse myelitis developed again, this time affecting the cervical spinal cord. Despite aggressive intervention with corticosteroids, the patient has remained nonambulatory with severe neurologic residua. In spite of an extensive workup, a definitive cause was not determined, although an autoimmune etiology was suspected. The patient has stabilized without recurrence using immunosuppressant therapies. CONCLUSIONS: Acute transverse myelitis is an intramedullary spinal cord disorder that may present to the spine specialist during the postoperative period. This diagnosis requires swift and aggressive diagnostic and treatment intervention. Although sometimes difficult, establishment of causation may help to determine therapy and prognosis.

Upper cervical spine injuries.

The unique anatomy of the upper cervical spine and the typical mechanisms of injury yield a predictable variety of injury patterns. Traumatic ligamentous injuries of the atlanto-occipital joint and transverse atlantal ligament are relatively uncommon, have a poor prognosis for healing, and often respond best to surgical stabilization. Bony injuries, including occipital condyle fractures, atlas fractures, most odontoid fractures, and traumatic spondylolisthesis of the axis, generally respond well to nonsurgical management. Controversy in management remains, however, especially with type II odontoid fractures.