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Lee Onn Chieng, Karthik Madhavan and Steven Vanni

OBJECT

Rheumatoid arthritis (RA) is one of the most debilitating autoimmune diseases affecting the craniovertebral junction (CVJ). Patients predominantly present with myelopathic symptoms and intractable neck pain. The surgical approach traditionally has been either a combined anterior and posterior approach or a posterior-only approach. In this article, the authors review pooled data from the literature and discuss the benefits of the two types of approaches.

METHODS

A search of the PubMed database was conducted using key words that describe spine deformities in RA and specific spinal interventions. The authors evaluated the neurological outcomes based on the Ranawat scale in both the groups through chi-square analysis. Multiple logistic regression was carried out to further examine for potential confounders. Any adverse sequalae resulting from either approach were also documented. Because all the procedures performed via a transoral approach in the analyzed articles also involved posterior fixation, for convenience of comparison, the combined procedures are referred to as “anterior approach” or “anterior-posterior” in the present study.

RESULTS

The search yielded 233 articles, of which 11 described anterior approaches and 14 evaluated posterior approaches. The statistical analysis showed that patients treated with a posterior approach fared better than those treated with an anterior (combined) approach. It was noted that those patients in whom the cervical subluxations were reducible on traction predominantly underwent posterior approaches.

CONCLUSIONS

CVJ instability is a serious complication of RA that requires surgical intervention. Although the anterior-posterior combined approach can provide direct decompression, it is associated with morbidity, and the analysis showed no statistically significant benefit to patients. In contrast, the posterior approach has been shown to provide statistically significant superiority with respect to stabilization and subsequent pannus reduction. Surgical approaches are undertaken based on the reducibility of subluxations with traction and the vector of compressive force. However, the choice of surgical approach should be based on the individual patient's pathology.

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Karthik Madhavan, Lee Onn Chieng, Hanyao Foong and Michael Y. Wang

OBJECTIVE

Cervical spondylotic myelopathy usually presents in the 5th decade of life or later but can also present earlier in patients with congenital spinal stenosis. As life expectancy continues to increase in the United States, the preconceived reluctance toward operating on the elderly population based on older publications must be rethought. It is a known fact that outcomes in the elderly cannot be as robust as those in the younger population. There are no publications with detailed meta-analyses to determine an acceptable level of outcome in this population. In this review, the authors compare elderly patients older than 75 years to a nonelderly population, and they discuss some of the relevant strategies to minimize complications.

METHODS

In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, the authors performed a PubMed database search to identify English-language literature published between 1995 and 2015. Combinations of the following phrases that describe the age group (“elderly,” “non-elderly,” “old,” “age”) and the disease of interest as well as management (“surgical outcome,” “surgery,” “cervical spondylotic myelopathy,” “cervical degenerative myelopathy”) were constructed when searching for relevant articles. Two reviewers independently assessed the outcomes, and any disagreement was discussed with the first author until it was resolved. A random-effects model was applied to assess pooled data due to high heterogeneity between studies. The mean difference (MD) and odds ratio were calculated for continuous and dichromatic parameters, respectively.

RESULTS

Eighteen studies comprising elderly (n = 1169) and nonelderly (n = 1699) patients who received surgical treatment for cervical spondylotic myelopathy were included in this meta-analysis. Of these studies, 5 were prospective and 13 were retrospective. Intraoperatively, both groups required a similar amount of operation time (p = 0.35). The elderly group had lower Japanese Orthopaedic Association (JOA) scores (MD −1.36, 95% CI −1.62 to −1.09; p < 0.00001) to begin with compared with the nonelderly group. The nonelderly group also had a higher postoperative JOA score (MD −1.11, 95% CI −1.44 to −0.79; p < 0.00001), therefore demonstrating a higher recovery rate from surgeries (MD −11.98, 95% CI −16.16 to −7.79; p < 0.00001). The length of stay (MD 4.14, 95% CI 3.54–4.73; p < 0.00001) was slightly longer in the elderly group. In terms of radiological outcomes, the elderly group had a smaller postoperative Cobb angle but a greater increase in spinal canal diameter compared with the nonelderly group. The complication rates were not significant.

CONCLUSIONS

Cervical myelopathy is a disease of the elderly, and age is an independent factor for recovery from surgery. Postoperative and long-term outcomes have been remarkable in terms of improvement in mobility and independence requiring reduced nursing care. There is definitely a higher potential risk while operating on the elderly population, but no significant difference in the incidence of postoperative complications was noted. Withholding surgery from the elderly population can lead to increased morbidity due to rapid progression of symptoms in addition to deconditioning from lack of mobility and independence. Reduction in operative time under anesthesia, lower blood loss, and perioperative fluid management have been shown to minimize the complication rate. The authors request that neurosurgeons weigh the potential benefit against the risks for every patient before withholding surgery from elderly patients.

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Karthik Madhavan, John Paul G. Kolcun, Lee Onn Chieng and Michael Y. Wang

Surgical robots have captured the interest—if not the widespread acceptance—of spinal neurosurgeons. But successful innovation, scientific or commercial, requires the majority to adopt a new practice. “Faster, better, cheaper” products should in theory conquer the market, but often fail. The psychology of change is complex, and the “follow the leader” mentality, common in the field today, lends little trust to the process of disseminating new technology. Beyond product quality, timing has proven to be a key factor in the inception, design, and execution of new technologies. Although the first robotic surgery was performed in 1985, scant progress was seen until the era of minimally invasive surgery. This movement increased neurosurgeons’ dependence on navigation and fluoroscopy, intensifying the drive for enhanced precision. Outside the field of medicine, various technology companies have made great progress in popularizing co-robots (“cobots”), augmented reality, and processor chips. This has helped to ease practicing surgeons into familiarity with and acceptance of these technologies. The adoption among neurosurgeons in training is a “follow the leader” phenomenon, wherein new surgeons tend to adopt the technology used during residency. In neurosurgery today, robots are limited to computers functioning between the surgeon and patient. Their functions are confined to establishing a trajectory for navigation, with task execution solely in the surgeon’s hands. In this review, the authors discuss significant untapped technologies waiting to be used for more meaningful applications. They explore the history and current manifestations of various modern technologies, and project what innovations may lie ahead.

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Karthik Madhavan and Michael Y. Wang

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Karthik Madhavan, Lee Onn Chieng, Brandon G. Gaynor and Allan D. Levi

Retro-odontoid cysts that arise from the tectorial membrane are uncommon lesions that can occur in elderly patients. They arise secondary to degenerative changes, including calcium pyrophosphate deposition within the ligaments. Surgical treatment is indicated when these lesions result in intractable pain, instability, and/or myelopathy. Several surgical techniques to treat this condition exist, but the optimal approach in elderly patients with comorbidities remains controversial. Here, the authors present a case series of 3 patients who underwent successful resection of a retro-odontoid lesion performed through a transdural approach.

The patients were 70, 81, and 74 years old and presented with symptoms of cervical myelopathy. In consideration of their advanced age and the location of their lesion, resection via a posterior approach was considered. A 1- to 2-cm suboccipital craniectomy and C-1 and partial C-2 laminectomy were performed. These lesions could not be accessed via an extradural posterolateral approach, and so a transdural approach was performed. In the first 2 patients, a preexisting deformity prompted an instrumented fusion. In the third patient, only a lesion resection was performed. In each case, the dural opening was made using a paramedian ipsilateral-sided incision, and the lesion was resected through an incision in the anterior dura mater. Only the posterior dura was closed primarily. MR imaging evidence of excellent spinal cord decompression was evident in follow-up examinations.

Transdural resection of retro-odontoid cysts is a viable option for treating asymmetrical ventral extradural cysts. Results from this case series suggest that such an approach is safe and feasible and can provide an alternative to open or endoscopic anterior transpharyngeal approaches.

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Karthik Madhavan, Steven Vanni and Seth K. Williams

Object

The medical management of discitis and osteomyelitis with long-term antibiotic therapy and bracing usually results in eradicated infection. Surgical management is appropriate when medical management fails and in some cases with pyogenic deformity or neurological deficit. The success of surgery depends on adequate debridement of the necrotic infected disc and vertebral body, along with anterior column reconstruction and vertebral stabilization. Debridement is typically performed via an anterior retroperitoneal approach, which can necessitate mobilization of the great vessels for proper exposure. Mobilization can be technically difficult and lead to vascular injury. The purpose of this study was to evaluate an alternative technique for the surgical treatment of lumbar discitis and osteomyelitis using a direct lateral retroperitoneal approach, which allows for thorough debridement and anterior column reconstruction while avoiding the need to mobilize the great vessels.

Methods

A retrospective chart analysis was performed for all patients who had presented with lumbar discitis and osteomyelitis and had undergone surgical management via the direct lateral retroperitoneal approach in the period from 2006 to 2013. Collected data included surgical blood loss, perioperative complications (wound infection, vascular injury, approach-related complications, and neurological injury), need for secondary procedures, microbiological and laboratory results, and efficacy of infection eradication. Imaging studies were reviewed as well.

Results

Ten patients, 7 male and 3 female, underwent this procedure at the authors' institution in the defined period. Average blood loss was 272 ml (range 150–800 ml, with 800 ml in the only 2-level case). There were no vascular injuries. Average follow-up was 680 days, although 4 patients did not complete the follow-up beyond 6 months. Eight patients underwent immediate posterior pedicle screw instrumentation. Two patients did not undergo posterior instrumentation, and one of these developed a kyphotic deformity that required a secondary posterior procedure. Infection was eradicated in all patients according to a history, physical examination, imaging studies, and laboratory parameters (complete blood count, erythrocyte sedimentation rate, and C-reactive protein). One patient developed a painful neuroma at the iliac crest harvest site, and one patient had a retroperitoneal hematoma. Otherwise, there were no approach-related neurological injuries or complications. Neither was there any postoperative surgical site infection.

Conclusions

The direct lateral approach for the surgical treatment of lumbar discitis and osteomyelitis allows for thorough debridement and spinal reconstruction without the need to mobilize the great vessels. This technique effectively eradicated infection in all cases, with reasonable blood loss and no vascular injuries. This approach should be considered as an alternative to the open anterior approach. The authors recommend posterior instrumentation to prevent the development of kyphosis.

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Karthik Madhavan, Lee Onn Chieng, Christoph P. Hofstetter and Michael Y. Wang

Isthmic spondylolisthesis due to pars defects resulting from trauma or spondylolysis is not uncommon. Symptomatic patients with such pars defects are traditionally treated with a variety of fusion surgeries. The authors present a unique case in which such a patient was successfully treated with endoscopic discectomy without iatrogenic destabilization.

A 31-year-old man presented with a history of left radicular leg pain along the distribution of the sciatic nerve. He had a disc herniation at L5/S1 and bilateral pars defects with a Grade I spondylolisthesis. Dynamic radiographic studies did not show significant movement of L-5 over S-1. The patient did not desire to have a fusion. After induction of local anesthesia, the patient underwent an awake transforaminal endoscopic discectomy via the extraforaminal approach, with decompression of the L-5 and S-1 nerve roots. His preoperative pain resolved immediately, and he was discharged home the same day. His preoperative Oswestry Disability Index score was 74, and postoperatively it was noted to be 8. At 2-year follow-up he continued to be symptom free, and no radiographic progression of the listhesis was noted.

In this case preservation of stabilizing structures, including the supraspinous and interspinous ligaments and the facet capsule, may have reduced the likelihood of iatrogenic instability while at the same time achieving symptom control. This may be a reasonable option for select patient symptoms confined to lumbosacral radiculopathy.

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Karthik Madhavan, Lee Onn Chieng, Valerie L. Armstrong and Michael Y. Wang

OBJECTIVE

Discitis and osteomyelitis are seen in end-stage renal disease (ESRD) patients due to repeated vascular access for hemodialysis and urinary tract infections leading to recurrent bacteremia. Discitis and osteomyelitis are underdiagnosed due to the nonspecific initial presentation of back pain. In this article, we review the literature for better understanding of the problem and the importance of early diagnosis by primary care physicians and nephrologists. In addition, we discuss the decision-making, follow-up, management, and neurological outcomes.

METHODS

A detailed PubMed search was performed using the following terms: “end stage renal disease (ESRD)” and “chronic renal failure (CRF),” combined with “spine infections,” “spondylodiscitis,” “discitis,” and “osteomyelitis.” Search results were limited to articles written in English, case reports, and case series from 1973 to 2012. Editorials, reviews, and commentaries were excluded. Only studies involving human patients were included. The authors also included 4 patients from their own patient population.

RESULTS

A total of 30 articles met the inclusion criteria. Including the 4 patients from the authors’ patient population, 212 patients with spine infections and maintenance dialysis were identified. The patients’ ages ranged from 38 to 78 years. The duration of dialysis ranged from a few days to 16 years. The time from onset of back pain to diagnosis ranged from 3 days to 6 months. The most common causative organism was Staphylococcus aureus, followed by Staphylococcus epidermidis and gram-negative bacteria. Most of the patients were treated with antibiotics alone (76.8%), although surgery was indicated when patients presented with neurological deficits (p < 0.011). Approximately one-quarter of the patients developed neurological deficits, with devastating consequences. Fever and neurological deficits at presentation, culture positive for methicillin-resistant S. aureus, and age > 65 years were highly correlated with mortality in our analysis.

CONCLUSIONS

Several risk factors lead to failure of antibiotics and progression of disease in patients with ESRD. Challenges to diagnosis include vague presenting symptoms, co-existing destructive spondyloarthropathy, poor immune response, chronic elevations of inflammatory markers, and recurrent bacteremia. Infectious processes are more likely to cause permanent neurological deficits than transient deficits. The authors recommend close observation and serial imaging of these patients for early signs of neurological deficits. Any signs of disease progression will require aggressive surgical debridement.

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Brian J. Dlouhy, Ana W. Capuano, Karthik Madhavan, James C. Torner and Jeremy D. W. Greenlee

Object

Patients with hydrocephalus often present with both intraventricular obstructive and communicating components, and determination of the predominant component is difficult. Other investigators have observed that third ventricular floor deformation, or “bowing” of the third ventricular floor, is a good indicator of intraventricular obstructive hydrocephalus, resulting in higher success rates with endoscopic third ventriculostomy (ETV). However, additional third ventricular bowing assessment and statistical evidence demonstrating a difference in ETV outcome with third ventricular bowing is needed. The authors hypothesized that patients with preoperative bowing of the third ventricle would exhibit greater long-term success rates after ETV and that lack of bowing would result in increased failure rates after ETV.

Methods

The authors determined success and failure for 59 ETVs performed in 56 patients, and recorded patient age, time to failure, and preoperative third ventricular anatomy, as well as history of infection, intraventricular hemorrhage, and previous shunt. Third ventricular anatomy was assessed on MR imaging for bowing, which was classified as any of the following: depression of the third ventricular floor, enlargement of the supraoptic recess, anterior curvature of the lamina terminalis, dilation of the proximal aqueduct to a greater extent than the distal aqueduct, and blunting or posterior bowing of the suprapineal recess. Univariate and multivariate analyses of ETV failure and the time to failure were performed using logistic regression and the Cox proportional hazards model, respectively.

Results

After adjusting for patient age and history of infection, there was a significant association between lack of anterior third ventricular preoperative bowing (either lamina terminalis, supraoptic recess, or third ventricular floor) and ETV failure (adjusted HR 2.79, 95% CI 1.08–7.20). Of the patients with bowing, 70.5% experienced success with ETV, as did 33.3% of the patients without bowing. Among the individual structures, absence of bowing in the anterior aspect of the third ventricular floor was significantly associated with censored time to ETV failure (multivariate HR 2.59, 95% CI 1.01–6.66; final model including age and history of infection).

Conclusions

The presence of preoperative third ventricular bowing is predictive of ETV success, with nearly a 3-fold likelihood of success compared with patients treated with ETV in the absence of such bowing. Although bowing is predictive, 33% of patients without bowing were also treated successfully with ETV.

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Lynn B. McGrath Jr., Karthik Madhavan, Lee Onn Chieng, Michael Y. Wang and Christoph P. Hofstetter

Approximately half a million spinal fusion procedures are performed annually in the US. It is estimated that up to one-third of arthrodesis constructs require revision surgeries. In this study the authors present endoscopic treatment strategies targeting 3 types of complications following arthrodesis surgery: 1) adjacent-level foraminal stenosis; 2) foraminal stenosis at an arthrodesis segment; and 3) stenosis caused by a displaced interbody cage.

A retrospective chart review of 11 patients with a mean age of 68 ± 15 years was performed (continuous variables are shown as the mean ± SEM). All patients had a history of lumbar arthrodesis surgery and suffered from unilateral radiculopathy. Endoscopic revision surgeries were done as outpatient procedures, and there were no intraoperative or perioperative complications. The cohort included 3 patients with foraminal stenosis at the level of previous arthrodesis. They presented with unilateral radicular leg pain (visual analog scale [VAS] score: 7.3 ± 2.1) and were severely disabled, as evidenced by an Oswestry Disability Index (ODI) of 46 ± 4.9. Transforaminal endoscopic foraminotomies were performed, and at a mean follow-up time of 9.0 ± 2.5 months VAS was reduced by an average of 6.3. The cohort also includes 7 patients suffering unilateral radiculopathy due to adjacent-level foraminal stenosis. Preoperative VAS for leg pain of the symptomatic side was 6.0 ± 1.6, VAS for back pain was 5.2 ± 1.7, and ODI was 40 ± 6.33. Endoscopic decompression led to reduction of the ipsilateral leg VAS score by an average of 5, resulting in leg pain of 1 ± 0.5 at an average of 8 months of follow-up. The severity of back pain remained stable (VAS 4.2 ± 1.4). Two of these patients required revision surgery for recurrent symptoms. Finally, this study includes 1 patient who presented with weakness and pain due to retropulsion of an L5/S1 interbody spacer. The patient underwent an endoscopic interlaminar approach with partial resection of the interbody cage, which resulted in complete resolution of her radicular symptoms.

Endoscopic surgery may be a useful adjunct for management of certain arthrodesis-related complications. Endoscopic foraminal decompression of previously fused segments and resection of displaced interbody cages appears to have excellent outcomes, whereas decompression of adjacent segments remains challenging and requires further investigation.