When a dural defect is encountered during spine surgery, the dura mater must be reconstituted to minimize the occurrence of minor or major life-threatening sequelae. The neurosurgical literature lacks strategies for managing large dural defects encountered during surgery. The authors describe a 24-year-old man who developed cauda equina syndrome secondary to altered CSF flow in a large thoracolumbar arachnoid cyst. Surgical decompression and fenestration of the arachnoid cyst were performed, and the large dural defect was treated using a multilayer closure with collagen matrix, titanium mesh, and methylmethacrylate. At his 24-month postoperative follow-up, the patient had recovered full strength in his legs, and his sensory deficits and sexual dysfunction had resolved. His incision had healed well, and there were no signs of pseudomeningocele. He had no additional positional headaches. The defect was managed effectively with this technique. Although this technique is not a first-line strategy for dural closure in the spine, it can be considered in challenging cases when large dural defects are not amenable to traditional closure techniques.
Matthew T. Neal, Randall J. Hlubek, Alexander E. Ropper, and U. Kumar Kakarla
Michael A. Mooney, Mark E. Oppenlander, U. Kumar Kakarla, and Nicholas Theodore
Tumoral calcinosis is characterized by tumor-like deposition of calcium in periarticular soft tissue. Spinal involvement is rare, and perioperative diagnosis of tumoral calcinosis can be difficult because lesions may be confused with bony neoplasms. Symptoms of tumoral calcinosis result from bony involvement and/or direct compression of surrounding anatomical structures, for which treatment with surgical decompression can be highly successful. The craniovertebral junction is rarely affected by tumoral calcinosis, and patients with this condition may present with distinct symptoms. Herein, to their knowledge the authors present the first case of tumoral calcinosis affecting the craniovertebral junction in a patient who presented with severe dysphagia and required transoral decompression. Recognition of tumoral calcinosis by neurosurgeons is essential for facilitating diagnosis and treatment, and the transoral approach is an effective method for decompression in select patients.
JNSPG 75th Anniversary Invited Review Article
Corey T. Walker, U. Kumar Kakarla, Steve W. Chang, and Volker K. H. Sonntag
Insight into the historic contributions made to modern-day spine surgery provides context for understanding the monumental accomplishments comprising current techniques, technology, and clinical success. Only during the last century did surgical growth occur in the treatment of spinal disorders. With that growth came a renaissance of innovation, particularly with the evolution of spinal instrumentation and fixation techniques. In this article, the authors capture some of the key milestones that have led to the field of spine surgery today, with an emphasis on the historical advances related to instrumentation, navigation, minimally invasive surgery, robotics, and neurosurgical training.
Tyler S. Cole, Kaith K. Almefty, Jakub Godzik, Amy H. Muma, Randall J. Hlubek, Eduardo Martinez-del-Campo, Nicholas Theodore, U. Kumar Kakarla, and Jay D. Turner
Cervical spondylotic myelopathy (CSM) is the primary cause of adult spinal cord dysfunction. Diminished hand strength and reduced dexterity associated with CSM contribute to disability. Here, the authors investigated the impact of CSM severity on hand function using quantitative testing and evaluated the response to surgical intervention.
Thirty-three patients undergoing surgical treatment of CSM were prospectively enrolled in the study. An occupational therapist conducted 3 functional hand tests: 1) palmar dynamometry to measure grip strength, 2) hydraulic pinch gauge test to measure pinch strength, and 3) 9-hole peg test (9-HPT) to evaluate upper extremity dexterity. Tests were performed preoperatively and 6–8 weeks postoperatively. Test results were expressed as 1) a percentile relative to age- and sex-stratified norms and 2) achievement of a minimum clinically important (MCI) difference. Patients were stratified into groups (mild, moderate, and severe myelopathy) based on their modified Japanese Orthopaedic Association (mJOA) score. The severity of stenosis on preoperative MRI was graded by three independent physicians using the Kang classification.
The primary presenting symptoms were neck pain (33%), numbness (21%), imbalance (12%), and upper extremity weakness (12%). Among the 33 patients, 61% (20) underwent anterior approach decompression, with a mean (SD) of 2.9 (1.5) levels treated. At baseline, patients with moderate and low mJOA scores (indicating more severe myelopathy) had lower preoperative pinch (p < 0.001) and grip (p = 0.01) strength than those with high mJOA scores/mild myelopathy. Postoperative improvement was observed in all hand function domains except pinch strength in the nondominant hand, with MCI differences at 6 weeks ranging from 33% of patients in dominant-hand strength tests to 73% of patients in nondominant-hand dexterity tests. Patients with moderate baseline mJOA scores were more likely to have MCI improvement in dominant grip strength (58.3%) than those with low mJOA scores/severe myelopathy (30%) and high mJOA scores/mild myelopathy (9%, p = 0.04). Dexterity in the dominant hand as measured by the 9-HPT ranged from < 1 in patients with cord signal change to 15.9 in patients with subarachnoid effacement only (p = 0.03).
Patients with CSM achieved significant improvement in strength and dexterity postoperatively. Baseline strength measures correlated best with the preoperative mJOA score; baseline dexterity correlated best with the severity of stenosis on MRI. The majority of patients experienced MCI improvements in dexterity. Baseline pinch strength correlated with postoperative mJOA MCI improvement, and patients with moderate baseline mJOA scores were the most likely to have improvement in dominant grip strength postoperatively.
S. Harrison Farber, David J. Mauler, Soumya Sagar, Mark A. Pacult, Corey T. Walker, Michael A. Bohl, Laura A. Snyder, Kristina M. Chapple, Volker K. H. Sonntag, Juan S. Uribe, Jay D. Turner, Steve W. Chang, and U. Kumar Kakarla
Anterior cervical discectomy and fusion (ACDF) is a common and robust procedure performed on the cervical spine. Literature on ACDF for 4 or more segments is sparse. Increasing the number of operative levels increases surgical complexity, tissue retraction, and risks of complications, particularly dysphagia. The overall risks of these complications and rates of dysphagia are not well studied for surgery on 4 or more segments. In this study, the authors evaluated their institution’s perioperative experience with 4- and 5-level ACDFs.
The authors retrospectively reviewed patients who underwent 4- or 5-level ACDF at their institution over a 6-year period (May 2013–May 2019). Patient demographics, perioperative complications, readmission rates, and swallowing outcomes were recorded. Outcomes were analyzed with a multivariate linear regression.
A total of 174 patients were included (167 had 4-level and 7 had 5-level ACDFs). The average age was 60.6 years, and 54.0% of patients (n = 94) were men. A corpectomy was performed in 12.6% of patients (n = 22). After surgery, 56.9% of patients (n = 99) experienced dysphagia. The percentage of patients with dysphagia decreased to 22.8% (37/162) at 30 days, 12.9% (17/132) at 90 days, and 6.3% (5/79) and 2.8% (1/36) at 1 and 2 years, respectively. Dysphagia was more likely at 90 days postoperatively in patients with gastroesophageal reflux (OR 4.4 [95% CI 1.5–12.8], p = 0.008), and the mean (± SD) lordosis change was greater in patients with dysphagia than those without at 90 days (19.8° ± 13.3° vs 9.1° ± 10.2°, p = 0.003). Dysphagia occurrence did not differ with operative implants, including graft and interbody type. The mean length of time to solid food intake was 2.4 ± 2.1 days. Patients treated with dexamethasone were more likely to achieve solid food intake prior to discharge (OR 4.0 [95% CI 1.5–10.6], p = 0.004). Postsurgery, 5.2% of patients (n = 9) required a feeding tube due to severe approach-related dysphagia. Other perioperative complication rates were uniformly low. Overall, 8.6% of patients (n = 15) returned to the emergency department within 30 days and 2.9% (n = 5) required readmission, whereas 1.1% (n = 2) required unplanned return to surgery within 30 days.
This is the largest series of patients undergoing 4- and 5-level ACDFs reported to date. This procedure was performed safely with minimal intraoperative complications. More than half of the patients experienced in-hospital dysphagia, which increased their overall length of stay, but dysphagia decreased over time.