Minimally Invasive Transforaminal Lumbar Interbody Fusion Versus Percutaneous Endoscopic Lumbar Discectomy: Revision Surgery for Recurrent Herniation After Microendoscopic Discectomy

WORLD NEUROSURGERY 99: 89-95, 2017

Most patients with recurrence of microendoscopic discectomy (MED) need to receive revision surgery. Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and percutaneous endoscopic lumbar discectomy (PELD) are common operative methods for MED recurrence, but no study has been made to compare the clinical outcomes of these 2 surgical methods as revision surgery for MED recurrence.

METHODS: A total of 105 patients who underwent either MIS-TLIF (58 patients) or PELD (47 patients) for revision of MED recurrence were included in this study. Perioperative outcomes (operation time, blood loss, and hospital stay), total cost, pain and functional scores (visual analog scale, Oswestry Disability Index, 12-item short form health survey) with a 12-month follow-up visit and review of complications and recurrence within 12 months postoperatively were recorded and assessed.

RESULTS: No significant difference of clinical outcome over time was observed between these 2 approaches. Compared with MIS-TLIF, PELD was associated with greater satisfaction in the early stage after surgery; this effect was equalized after 3 months postoperatively. PELD brought advantages in terms of shorter operation time, shorter hospital stay, less blood loss, and lower total cost compared with MIS-TLIF; however, PELD was also associated with a higher recurrence rate than MIS-TLIF.

CONCLUSIONS: Neither of these 2 surgical methods gave a clear advantage in long-term pain or function scores. Compared with MIS-TLIF, PELD could lead to a better perioperative result and less cost; however, the higher recurrence rate could not be ignored. Taking these characteristics into consideration was instrumental in pursuing personalized treatment for MED recurrence.

A prospective randomized multicenter phase I/II clinical trial to evaluate safety and efficacy of NOVOCART disk plus autologous disk chondrocyte transplantation in the treatment of nucleotomized and degenerative lumbar disks to avoid secondary disease

Neurosurg Rev (2017) 40:155–162

NOVOCART ® Disk plus, an autologous cell compound for autologous disk chondrocyte transplantation, was developed to reduce the degenerative sequel after lumbar disk surgery or to prophylactically avoid degeneration in adjacent disks, if present. The NDisc trial is an on-going multi-center, randomized study with a sequential phase I study within the combined phase I/II trial with close monitoring of tolerability and safety.

Twenty-four adult patients were randomized and treated with the investigational medicinal product NDisc plus or the carrier material only. Rates of adverse events in Phase I of this trial were comparable with those expected in the early time course after elective disk surgery. There was one reherniation 7 months after transplantation, which corresponds to an expected reherniation rate. Immunological markers like CRP and IL-6 were not significantly elevated and there were no im- aging abnormalities. No indications of harmful material extrusion or immunological consequences due to the investigational medicinal product NDplus were observed.

Therefore, the study appears to be safe and feasible. Safety analyses of Phase I of this trial indicate a relatively low risk considering the benefits that patients with debilitating degenerative disk disease may gain.

 

The Relationship Between Preoperative Clinical Presentation and Quantitative Magnetic Resonance Imaging Features in Patients With Degenerative Cervical Myelopathy

Neurosurgery 80:121–128, 2017

Degenerative cervical myelopathy encompasses a group of conditions resulting in progressive spinal cord injury through static and dynamic compression. Although a constellation of changes can present on magnetic resonance imaging (MRI), the clinical significance of these findings remains a subject of controversy and discussion.

OBJECTIVE: To investigate the relationship between clinical presentation and quantitative MRI features in patients with degenerative cervical myelopathy.

METHODS: A secondary analysis of MRI and clinical data from 114 patients enrolled in a prospective, multicenter study was conducted. MRIs were assessed for maximum spinal cord compression (MSCC), maximum canal compromise (MCC), signal changes, and a signal change ratio (SCR). MRI features were compared between patients with and those without myelopathy symptoms with the use of t tests. Correlations between MRI features and duration of symptoms were assessed with the Spearman ρ.

RESULTS: Numb hands and Hoffmann sign were associated with greater MSCC (P < .05); broad-based, unstable gait, impairment of gait, and Hoffmann sign were associated with greaterMCC (P<.05); andnumbhands,Hoffmann sign, Babinski sign, lower limb spasticity, hyperreflexia, and T1 hypointensitywere associated with greater SCR (P<.05). Patientswith a T2 signal hyperintensity had greater MSCC and MCC (P < .001).

CONCLUSION: MSCC was associated with upper limb manifestations, and SCR was associated with upper limb, lower limb, and general neurological deficits. Hoffmann sign occurred more commonly in patients with a greater MSCC,MCC and SCR. The Lhermitte phenomenon presented more commonly in patientswith a lower SCR and may be an early indicator of mild spinal cord involvement. Research to validate these findings is required.

Deadly falls: operative versus nonoperative management of Type II odontoid process fracture in octogenarians

Journal of Neurosurgery: Spine – 26(1): 4-9

Type II odontoid fracture is a common injury among elderly patients, particularly given their predisposition toward low-energy falls. Previous studies have demonstrated a survival advantage following early surgery among patients older than 65 years, yet octogenarians represent a medically distinct and rapidly growing population. The authors compared operative and nonoperative management in patients older than 79 years.

METHODS  A single-center prospectively maintained trauma database was reviewed using ICD-9 codes to identify octogenarians with C-2 cervical fractures between 1998 and 2014. Cervical CT images were independently reviewed by blinded neurosurgeons to confirm a Type II fracture pattern. Prospectively recorded outcomes included Glasgow Coma Scale (GCS) score, Abbreviated Injury Scale (AIS) score, Injury Severity Score (ISS), additional cervical fracture, and cord injury. Primary end points were mortality at 30 days and at 1 year. Statistical tests included the Student t-test, chi-square test, Fisher’s exact test, Kaplan-Meier test, and Cox proportional hazard.

RESULTS  A total of 111 patients met inclusion criteria (94 nonoperative and 17 operative [15 posterior and 2 anterior]). Mortality data were available for 100% of patients. The mean age was 87 years (range 80–104 years). Additional cervical fracture, spinal cord injury, GCS score, AIS score, and ISS were not associated with either management strategy at the time of presentation. The mean time to death or last follow-up was 22 months (range 0–129 months) and was nonsignificant between operative and nonoperative groups (p = 0.3). Overall mortality was 13% in-hospital, 26% at 30 days, and 41% at 1 year. Nonoperative and operative mortality rates were not significant at any time point (12% vs 18%, p = 0.5 [in-hospital]; 27% vs 24%, p = 0.8 [30-day]; and 41% vs 41%, p = 1.0 [1-year]). Kaplan-Meier analysis did not demonstrate a survival advantage for either management strategy. Spinal cord injury, GCS score, AIS score, and ISS were significantly associated with 30-day and 1-year mortality; however, Cox modeling was not significant for any variable. Additional cervical fracture was not associated with increased mortality. The rate of nonhome disposition was not significant between the groups.

CONCLUSIONS  Type II odontoid fracture is associated with high morbidity among octogenarians, with 41% 1-year mortality independent of intervention—a dramatic decrease from actuarial survival rates for all 80-, 90-, and 100-year-old Americans. Poor outcome is associated with spinal cord injury, GCS score, AIS score, and ISS.

The ‘Lumbar Fusion Outcome Score’ (LUFOS): a new practical and surgically oriented grading system for preoperative prediction of surgical outcomes after lumbar spinal fusion in patients with degenerative disc disease and refractory chronic axial low back pain

Neurosurg Review (40) pp 67–81, 2017

In order to evaluate the predictive effect of non-invasive preoperative imaging methods on surgical outcomes of lumbar fusion for patients with degenerative disc disease (DDD) and refractory chronic axial low back pain (LBP), the authors conducted a retrospective review of 45 patients with DDD and refractory LBP submitted to anterior lumbar interbody fusion (ALIF) at a single center from 2007 to 2010.

Surgical outcomes – as measured by Visual Analog Scale (VAS/back pain) and Oswestry Disability Index (ODI) – were evaluated pre-operatively and at 6 weeks, 3 months, 6 months, and 1 year post-operatively. Linear mixed-effects models were generated in order to identify possible preoperative imaging characteristics (including bone scan/99mTc scintigraphy increased endplate uptake, Modic endplate changes, and disc degeneration graded according to Pfirrmann classification) which may be predictive of long-term surgical outcomes .

After controlling for confounders, a combined score, the Lumbar Fusion Outcome Score (LUFOS), was developed. The LUFOS grading system was able to stratify patients in two general groups (Non-surgical: LUFOS 0 and 1; Surgical: LUFOS 2 and 3) that presented significantly different surgical outcomes in terms of estimated marginal means of VAS/back pain (p = 0.001) and ODI (p = 0.006) beginning at 3 months and continuing up to 1 year of follow-up.

In conclusion, LUFOS has been devised as a new practical and surgically oriented grading system based on simple key parameters from non-invasive preoperative imaging exams (magnetic resonance imaging/MRI and bone scan/99mTc scintigraphy) which has been shown to be highly predictive of surgical outcomes of patients undergoing lumbar fusion for treatment for refractory chronic axial LBP.

Comparing clinical outcomes of repeat discectomy versus fusion for recurrent disc herniation utilizing the N2QOD

J Neurosurg Spine 26:39–44, 2017

Recurrent lumbar disc herniation (RLDH) is a significant cause of morbidity in patients undergoing lumbar discectomy and has been reported to occur in up to 18% of cases. While repeat discectomy is often successful in treating these patients, concern over repeat RLDH may lead surgeons to advocate instrumented fusion even in the absence of instability. The authors’ goal was to compare clinical outcomes for patients undergoing repeat discectomy versus instrumented fusion for RLDH.

Methods The authors used the National Neurosurgery Quality and Outcomes Database (N2QOD) to assess outcomes of patients who underwent repeat discectomy versus instrumented fusion at a single institution from 2012 to 2015. Primary outcomes included Oswestry Disability Index (ODI) score, visual analog scale (VAS) score, and quality-adjusted life year (QALY) measures. Secondary outcomes included hospital length of stay, discharge status, and hospital charges.

Results The authors identified 25 repeat discectomy and 12 instrumented fusion patients with 3- and 12-month follow-up records. The groups had similar ODI and VAS scores and QALY measurements at 3 and 12 months. Patients in the instrumented fusion group had significantly longer hospitalizations (3.7 days vs 1.0 days, p < 0.001) and operative times (229.6 minutes vs 82.7 minutes, p < 0.001). They were also more likely to be female (p = 0.020) and to be discharged to inpatient rehabilitation instead of home (p = 0.036). Hospital charges for the instrumented fusion group were also significantly higher ($54,458.29 vs $11,567.05, p < 0.001). Rates of reoperation were higher in the repeat discectomy group (12% vs 0%), but the difference was not statistically significant (p = 0.211).

Conclusions Repeat discectomy and instrumented fusion result in similar clinical outcomes at short-term follow-up. Patients undergoing repeat discectomy had significantly shorter operative times and length of stay, and they incurred dramatically lower hospital charges. They were also less likely to require acute rehabilitation postoperatively. Further research is needed to compare these two management strategies.

Image-guided resection of aggressive sacral tumors

Neurosurg Focus 42 (1):E15, 2017

The aim of this study was to identify and discuss operative nuances utilizing image guidance in the surgical management of aggressive sacral tumors.

Methods: The authors report on their single-institution, multi-surgeon, retrospective case series involving patients with pathology-proven aggressive sacral tumors treated between 2009 and 2016. They also reviewed the literature to identify articles related to aggressive sacral tumors, their diagnosis, and their surgical treatment and discuss the results together with their own experience. Information, including background, imaging, treatment, and surgical pearls, is organized by tumor type.

Results: Review of the institutional records identified 6 patients with sacral tumors who underwent surgery between 2009 and 2016. All 6 patients were treated with image-guided surgery using cone-beam CT technology (O-arm). The surgical technique used is described in detail, and 2 illustrative cases are presented. From the literature, the authors compiled information about chordomas, chondrosarcomas, giant cell tumors, and osteosarcomas and organized it by tumor type, providing a detailed discussion of background, imaging, and treatment as well as surgical pearls for each tumor type.

Conclusions: Aggressive sacral tumors can be an extremely difficult challenge for both the patient and the treating physician. The selected surgical intervention varies depending on the type of tumor, size, and location. Surgery can have profound risks including neural compression, lumbopelvic instability, and suboptimal oncological resection. Focusing on the operative nuances for each type can help prevent many of these complications. Anecdotal evidence is provided that utilization of image-guided surgery to aid in tumor resection at our institution has helped reduce blood loss and the local recurrence rate while preserving function in both malignant and aggressive benign tumors affecting the sacrum.

Lateral interbody fusion combined with open posterior surgery for adult spinal deformity

J Neurosurg Spine 25:697–705, 2016

Lateral interbody fusion (LIF) with percutaneous screw fixation can treat adult spinal deformity (ASD) in the coronal plane, but sagittal correction is limited. The authors combined LIF with open posterior (OP) surgery using facet osteotomies and a rod-cantilever technique to enhance lumbar lordosis (LL). It is unclear how this hybrid strategy compares to OP surgery alone. The goal of this study was to evaluate the combination of LIF and OP surgery (LIF+OP) for ASD.

Methods All thoracolumbar ASD cases from 2009 to 2014 were reviewed. Patients with < 6 months follow-up, prior fusion, severe sagittal imbalance (sagittal vertical axis > 200 mm or pelvic incidence-LL > 40°), and those undergoing anterior lumbar interbody fusion were excluded. Deformity correction, complications, and outcomes were compared between LIF+OP and OP-only surgery patients.

Results LIF+OP (n = 32) and OP-only patients (n = 60) had similar baseline features and posterior fusion levels. On average, 3.8 LIFs were performed. Patients who underwent LIF+OP had less blood loss (1129 vs 1833 ml, p = 0.016) and lower durotomy rates (0% vs 23%, p = 0.002). Patients in the LIF+OP group required less ICU care (0.7 vs 2.8 days, p < 0.001) and inpatient rehabilitation (63% vs 87%, p = 0.015). The incidence of new leg pain, numbness, or weakness was similar between groups (28% vs 22%, p = 0.609). All leg symptoms resolved within 6 months, except in 1 OP-only patient. Follow-up duration was similar (28 vs 25 months, p = 0.462). LIF+OP patients had significantly less pseudarthrosis (6% vs 27%, p = 0.026) and greater improvement in visual analog scale back pain (mean decrease 4.0 vs 1.9, p = 0.046) and Oswestry Disability Index (mean decrease 21 vs 12, p = 0.035) scores. Lumbar coronal correction was greater with LIF+OP surgery (mean [± SD] 22° ± 13° vs 14° ± 13°, p = 0.010). LL restoration was 22° ± 13°, intermediately between OP-only with facet osteotomies (11° ± 7°, p < 0.001) and pedicle subtraction osteotomy (29° ± 10°, p = 0.045).

Conclusions LIF+OP is an effective strategy for ASD of moderate severity. Compared with the authors’ OP-only operations, LIF+OP was associated with faster recovery, fewer complications, and greater relief of pain and disability.

Contribution of Lordotic Correction on C5 Palsy Following Cervical Laminectomy and Fusion

Neurosurgery 79:816–822, 2016

C5 palsy is a well-reported complication of cervical spine surgery. The implication of sagittal cervical alignment parameters and their changes after surgery on the incidence of C5 palsy remains unclear.

OBJECTIVE: We review cervical alignment changes in our cases of C5 palsy after cervical laminectomy and fusion.

METHODS: Cases of C5 palsy were retrospectively compared with a control group. Preoperative and postoperative upright plain film radiographs were analyzed in blinded fashion.

RESULTS: Spine registry analysis identified 148 patients who underwent cervical laminectomy and fusion by the senior author over 5 years. There were 18 (12%) cases complicated by postoperative C5 palsy. Nine of these 18 patients had prerequisite upright films and were compared with a randomly constructed case control group of 20 patients. There were no statistically significant differences between the 2 groups in age, proportion of males, and preoperative Nurick score. Measures of sagittal alignment did not differ significantly between the 2 groups on preoperative and postoperative imaging. When comparing the amount of alignment change between preoperative and postoperative upright imaging, however, patients with C5 palsy had a statistically higher amount of average C4-C5 Cobb angle change (22.53 vs 0.78; P = .01). Logistic regression analysis demonstrated that lordotic change in both C4-C5 and C2-C7 Cobb angles were associated with development of palsy.

CONCLUSION: Lordotic cervical correction, as measured on upright imaging, was statistically larger in patients who had C5 palsy. The role of deformity correction in C5 palsy deserves further study and may inform intraoperative decision making.

The Effect of Lumbar Spinal Muscle on Spinal Sagittal Alignment

Neurosurgery 79:847–855, 2016

The majority of earlier studies of the parameters of sagittal balance did not consider the influence of spinal muscles on spinal sagittal alignment.

OBJECTIVE: To analyze the relationship between the paraspinal muscle (quantity and quality) and sagittal alignment in elderly patients.

METHODS: We reviewed 50 full-spine lateral standing radiographs and lumbar magnetic resonance images of elderly patients at a single center. The radiographic parameters examined were thoracic kyphosis, lumbar lordosis (LL), sagittal vertical axis, pelvic tilt, sacral slope, and pelvic incidence (PI). The lumbar muscularity (LM; quantity) and fatty degeneration ratio (FD; quality) in the paraspinal muscle were measured at the L3 level on magnetic resonance images. The relationships between the parameters, LM, and FD were analyzed with the Pearson correlation coefficient and multiple linear regression.

RESULTS: Pearson analysis demonstrated that the FD had significant correlations with age (r = 0.393), thoracic kyphosis (r = 20.559), pelvic tilt (r = 0.430), sagittal vertical axis (r = 0.488), and PI 2 LL (r = 0.479, P , .05), and a close negative correlation was found between the FD and LL (r = 20.505, P , .01). The LM had significant correlations with the LL (r = 0.342) and PI 2 LL (r = 20.283, P , .05). Regression models that controlled for confounding factors such as body mass index confirmed the correlations between the above parameters and FD (P , .05).

CONCLUSION: The quality of the paraspinal muscle could be one of the various factors that influence sagittal balance.

The Mini-Open Pedicle Subtraction Osteotomy for Flat-Back Syndrome and Kyphosis Correction

Operative Neurosurgery 12:309–316, 2016

The pedicle subtraction osteotomy (PSO) has been a mainstay treatment for flat-back syndrome. The morbidity of open deformity correction can be high, and minimally invasive applications may reduce such morbidity.

OBJECTIVE: To describe an operative technique of the mini-open PSO.

METHODS: Two patients underwent percutaneous fixation above and below the PSO, and the PSO was performed in a mini-open fashion. The correction was obtained by cantilever.

RESULTS: The patient who underwent the L3 PSO had a prior fusion from T11 to L4 for scoliosis 35 years ago. On presentation at 62 years of age, he had a pelvic incidence of 54, lumbar lordosis of 23, sagittal vertical axis of 114 cm, and pelvic tilt of 25. He underwent an anterior lumbar interbody fusion at L5-S1 followed by a min-open L3 PSO. He had a postoperative lumbar lordosis of 64 (correction of 41), and his sagittal vertical axis went to 13 cm. His Oswestry Disability Index and visual analog scale scores decreased after surgery. The second patient was 64 years of age and underwent an L1 PSO. He had 43 of kyphosis from T10 to L2. He had a preoperative pelvic incidence of 63, lumbar lordosis of 35, pelvic tilt of 24, and sagittal vertical axis of 3 cm. His postoperative kyphosis improved from 43 to 32.

CONCLUSION: The mini-open PSO can achieve significant lordosis, although it is heavily reliant on anterior arthrodesis. Larger studies are needed to compare this approach with an open PSO.

Surgical excision of symptomatic sacral perineurial Tarlov cyst

tarlov-cysts

Eur Spine J (2016) 25:3385–3392

Symptomatic sacral perineural cysts are extremely rare. The aim of this retrospective study is to investigate the outcome of 15 consecutive patients treated by microsurgical resection of the cyst and to review the literature.

Methods The authors retrospectively reviewed their clinical data archive from 2002 to 2014. Fifteen patients who were operated on due to symptomatic sacral perineural cysts were enrolled in the study. Patients’ symptoms, radiographs, intra-operative findings, and clinical results were evaluated. All 15 patients underwent microsurgical excision of the cyst. The literature on this topic available in PubMed was also reviewed.

Results There were 5 men and 10 women included in the study, with a mean age of 31 years (range 7–60 years). Preoperative symptoms include low back pain, coccydynia, buttock pain, perianal pain and radicular pain. All of the patients underwent surgical resection. The mean follow-up was 54 months (range 3–160 months). All the patients experienced complete or substantial resolution of the preoperative local and radicular pain after surgery.

Conclusions Cyst excision is an effective and safe technique for symptomatic sacral perineural (Tarlov) cysts. Careful patient selection is vital to the management and treatment of this difficult and controversial pathology.

Back pain improvement after decompression without fusion or stabilization in patients with lumbar spinal stenosis and clinically significant preoperative back pain

lumbar stenosis

J Neurosurg Spine 25:596–601, 2016

The relief of leg symptoms by surgical decompression for lumbar stenosis is well supported by the literature. Less is known about the effect on back pain. Some surgeons believe that the relief of back pain should not be an expected outcome of decompression and that substantial back pain may be a contraindication to decompression only; therefore, stabilization may be recommended for patients with substantial preoperative back pain even in the absence of well-accepted indications for stabilization such as spondylolisthesis, scoliosis, or sagittal malalignment. The purpose of this study is to determine if patients with lumbar stenosis and substantial back pain—in the absence of spondylolisthesis, scoliosis, or sagittal malalignment—can obtain significant improvement after decompression without fusion or stabilization.

Methods Analysis of the National Neurosurgery Quality and Outcomes Database (N2QOD) identified 726 patients with lumbar stenosis (without spondylolisthesis or scoliosis) and a baseline back pain score ≥ 5 of 10 who underwent surgical decompression only. No patient was reported to have significant spondylolisthesis, scoliosis, or sagittal malalignment. Standard demographic and surgical variables were collected, as well as patient outcomes including back and leg pain scores, Oswestry Disability Index (ODI), and EuroQoL 5D (EQ-5D) at baseline and 3 and 12 months postoperatively.

Results The mean age of the cohort was 65.6 years, and 407 (56%) patients were male. The mean body mass index was 30.2 kg/m2, and 40% of patients had 2-level decompression, 29% had 3-level decompression, 24% had 1-level decompression, and 6% had 4-level decompression. The mean estimated blood loss was 130 ml. The mean operative time was 100.85 minutes. The vast majority of discharges (88%) were routine home discharges. At 3 and 12 months postoperatively, there were significant improvements from baseline for back pain (7.62 to 3.19 to 3.66), leg pain (7.23 to 2.85 to 3.07), EQ-5D (0.55 to 0.76 to 0.75), and ODI (49.11 to 27.20 to 26.38).

Conclusions Through the 1st postoperative year, patients with lumbar stenosis—without spondylolisthesis, scoliosis, or sagittal malalignment—and clinically significant back pain improved after decompression-only surgery.

Predictors of an unfavorable outcome 1.5 and 12 years after a first, uncomplicated lumbar disc surgery

How to predict return to work after lumbar discectomy- answers from the NeuroPoint-SD registry

Eur Spine J (2016) 25:3520–3527

To identify predictors of both intermediate and long-term unfavorable outcomes after first time, uncomplicated lumbar disc surgery.

Methods Patients (n = 120) who had undergone lumbar disc surgery were followed up 1.5 and 12 years thereafter. Baseline assessments were carried out 5–8 days after surgery. Clinical outcome was assessed in both follow-ups using the Low Back Pain Rating Scale. Statistical analysis included binary logistic and linear regression.

Results Unfavorable outcomes were found in 50.5 % (1.5 years) and 52.6 % (12 years) of patients available for follow-up examination. Low pre-operative physical activity and severe pain in the first week after surgery were predictive of an unfavorable post-operative outcome at both follow-ups.

Conclusions Identified predictors suggest that particular emphasis should put on comprehensive post-operative care at large and encouragement to adapt a physically active lifestyle in particular in rehabilitation concepts after first time uncomplicated lumbar disc surgery.

Effect of Surgery on Gait and Sensory Motor Performance in Patients With Cervical Spondylotic Myelopathy

Evaluation of spinal cord compression and hyperintense intramedullary lesions on T2-weighted sequences in patients with cervical spondylotic myelopathy using flexion-extension MRI protocol

Neurosurgery 79:701–707, 2016

Cervical spondylotic myelopathy (CSM) is a common disease of aging that leads to gait instability resulting from loss of leg sensory and motor functions. The results of surgical intervention have been studied using a variety of methods, but no test has been reported that objectively measures integrative leg motor sensory functions in CSM patients.
OBJECTIVE: To determine the feasibility of using a novel single leg squat (SLS) test to measure integrative motor sensory functions in patients with CSM before and after surgery.
METHODS: Fifteen patients with CSM were enrolled in this prospective study. Clinical data and scores from standard outcomes questionnaires were obtained before and after surgery. Patients also participated in experimental test protocols consisting of standard kinematic gait testing, the Purdue pegboard test, and the novel SLS test.
RESULTS: The SLS test protocol was well tolerated by CSM patients and generated objective performance data over short test periods. In patients who participated in postoperative testing, the group measures of mean SLS errors decreased following surgery. Gait velocity measures followed a similar pattern of group improvement postoperatively. Practical barriers to implementing this extensive battery of tests resulted in subject attrition over time. Compared with kinematic gait testing, the SLS protocol required less space and could be effectively implemented more efficiently.
CONCLUSIONS: The SLS test provides a practical means of obtaining objective measures of leg motor sensory functions in patients with CSM. Additional testing with a larger cohort of patients is required to use SLS data to rigorously examine group treatment effects.

 

 

Novel dural incision and closure procedure for preventing postoperative cerebrospinal fluid leakage during the surgical removal of dumbbell-shaped spinal tumors

novel-technique-for-dumbbell-shaped-spinal-tumors

J Neurosurg Spine 25:620–625, 2016

The authors report on a new method for removing dumbbell-shaped spinal tumors that avoids the risk of postoperative cerebrospinal fluid (CSF) leakage.

Adequate visualization of the intra- and extradural components of the tumor is achieved with the use of separate dural incisions. First, the dura mater is opened along the dural theca to provide adequate visualization of the intradural portion of the mass; then, a second incision is made along the nerve root to remove the extradural component.

Meticulous suturing is essential in intradural lesion cases; however, the dura mater is usually thin and fragile in such cases. During suturing with a needle and thread, the dura mater can become lacerated proximal to the needle holes and result in CSF leakage.

In the authors’ technique, instead of using a needle and thread, nonpenetrating vascular clips were used to close the dural incisions. When operating on dumbbell-shaped spinal tumors, the authors found that the “separate-dural-incision method” was preferable to the conventional T-shaped dural incision method because no dural defects occurred after the intradural procedure and meticulous dural closure with vascular clips was achieved.

The authors conclude that the novel separate-dural-incision method for removing dumbbell-shaped tumors and the use of nonpenetrating vascular clips permits reliable dural closure, prevents postoperative CSF leakage, and promises good postoperative clinical results.

Surgical outcomes of PLIF with CBT screw fixation

surgical-outcomes-of-plif-with-cbt-screw-fixation

J Neurosurg Spine 25:591–595, 2016

Several biomechanical studies have demonstrated the favorable mechanical properties of the cortical bone trajectory (CBT) screw. However, no reports have examined surgical outcomes of posterior lumbar interbody fusion (PLIF) with CBT screw fixation for degenerative spondylolisthesis (DS) compared with those after PLIF using traditional pedicle screw (PS) fixation. The purposes of this study were thus to elucidate surgical outcomes after PLIF with CBT screw fixation for DS and to compare these results with those after PLIF using traditional PS fixation.

Methods Ninety-five consecutive patients underwent PLIF with CBT screw fixation for DS (CBT group; mean followup 35 months). A historical control group consisted of 82 consecutive patients who underwent PLIF with traditional PS fixation (PS group; mean follow-up 40 months). Clinical status was assessed using the Japanese Orthopaedic Association (JOA) scale score. Fusion status was assessed by dynamic plain radiographs and CT. The need for additional surgery and surgery-related complications was also evaluated.

Results The mean JOA score improved significantly from 13.7 points before surgery to 23.3 points at the latest follow-up in the CBT group (mean recovery rate 64.4%), compared with 14.4 points preoperatively to 22.7 points at final follow-up in the PS group (mean recovery rate 55.8%; p < 0.05). Solid spinal fusion was achieved in 84 patients from the CBT group (88.4%) and in 79 patients from the PS group (96.3%, p > 0.05). Symptomatic adjacent-segment disease developed in 3 patients from the CBT group (3.2%) compared with 9 patients from the PS group (11.0%, p < 0.05).

Conclusions PLIF with CBT screw fixation for DS provided comparable improvement of clinical symptoms with PLIF using traditional PS fixation. However, the successful fusion rate tended to be lower in the CBT group than in the PS group, although the difference was not statistically significant between the 2 groups.

Four-year results of a prospective single-arm study on 200 semi-constrained total cervical disc prostheses

activ-c-xray

J Neurosurg Spine 25:556–565, 2016

Recent studies have described encouraging outcomes after cervical total disc replacement (cTDR), but there are also critical debates regarding the long-term effects of heterotopic ossification (HO) and the prevalence of adjacent-level degeneration. The aim in this paper was to provide 4-year clinical and radiographic outcome results on the activ C disc prosthesis.

Methods A total of 200 subjects underwent single-level activ C (Aesculap AG) implantation between C-3 and C-7 for the treatment of symptomatic degenerative disc disease. Clinical and radiographic assessments were performed preoperatively, intraoperatively, at discharge, and again at 6 weeks, 6 months, 1 year, 2 years, and 4 years. Radiographic evaluations were done by an independent core laboratory using a specific software for quantitative motion analysis.

Results Neck Disability Index (NDI) and visual analog scale (VAS) score for neck and arm pain decreased significantly from baseline to the 4-year follow-up. The mean improvement for NDI was 20, for VAS severity and frequency of neck pain 26.4 and 28, and for VAS severity and frequency of arm pain 30.7 and 35.1, respectively. The neurological situation improved for the majority of patients (86.4%); 76.1% of cases were asymptomatic. Subsequent surgical interventions were reported in 7% of the cases, including device removals in 3%. In 2.5% a subsidence greater than 3 mm was recorded; 1 of these cases also had a migration greater than 3 mm. No device displacement, expulsion, disassembly, loose or fractured device, osteolysis, or facet joint degeneration at the index level was observed. Segmental lordotic alignment changed from -2.4° preoperatively to -6.2° at 4 years, and postoperative height was maintained during the follow-up. Advanced HO (Grade III and IV) was present in 27.1% of the cases; 82.4% showed segmental mobility. A progression of radiographic adjacent-segment degeneration occurred in 28.2%, but only 4.5% required surgical treatment.

Conclusions The activ C is a safe and effective device for cervical disc replacement confirming the encouraging results after cTDR.

Cervical corpectomies: results of a survey and review of the literature on diagnosis, indications, and surgical technique

Anterior cervical discectomy versus corpectomy for multilevel cervical spondylotic myelopathy

Acta Neurochir (2016) 158:1859–1867

Cervical corpectomy is an uncommon procedure and there are only limited data on the procedure’s indications, surgical approaches, and complications. The diagnosis, indications, surgical planning, and complications of cervical corpectomy were therefore surveyed to clarify the treatment strategies used by spinal surgeons in central Europe, with special attention to preoperative planning and decisionmaking for additional dorsal approaches in multilevel cases.

Materials and methods An online survey with 18 questions on the preoperative, intraoperative, and postoperative management of cervical corpectomies was conducted. The relevant specialist societies in Germany and Austria provided 1137 contacts for surgeons, and the responses were compared with recent literature reports.

Results In all, 302 surgeons (27 %) completed the survey, with wide variability in the treatment options offered. Most (51 %) perform fewer than five anterior cervical corpectomy and fusion (ACCF) procedures per year; 35 % do 5–20 per year. Anterior cervical discectomy and fusion (ACDF) was preferred by 41 % of the participants to laminoplasty/ laminectomy (19 %/16 %) and ACCF (12 %). Most indications for ACCF involved degenerative (27 %), traumatic (17 %), and neoplastic (20 %) conditions. Intraoperative and postoperative complications were mainly associated with hardware failure. One-third of the surgeons tend to use an additional dorsal approach to increase the corpectomy construct’s stability for either two-level or three-level corpectomies.

Conclusions There is no current consensus in central Europe on the treatment of complex cervical disease and cervical corpectomy. The procedure is still rare, and the need for additional dorsal fixation is unclear. Further studies are needed in order to establish evidence-based standards for patient care.

Functional magnetic resonance imaging evaluation of lumbosacral radiculopathic pain

functional-mri-evaluation-of-lumbosacral-radiculopathic-pain

J Neurosurg Spine 25:517–522, 2016

An objective biomarker for pain is yet to be established. Functional MRI (fMRI) is a promising neuroimaging technique that may reveal an objective radiological biomarker. The purpose of this study was to evaluate fMRI technology in the setting of lumbosacral radiculopathy and discuss its application in revealing a biomarker for pain in the future.

Methods A prospective, within-participant control study was conducted. Twenty participants with painful lumbosacral radiculopathy from intervertebral disc pathology were recruited. Functional imaging of the brain was performed during a randomly generated series of nonprovocative and provocative straight leg raise maneuvers.

Results With a statistical threshold set at p < 0.000001, 3 areas showed significant blood oxygen level–dependent (BOLD) signal change: right superior frontal gyrus (x = 2, y = 13, z = 48, k = 29, Brodmann area 6 [BA6]), left supramarginal cortex (x = -37, y = -44, z = 33, k = 1084, BA40), and left parietal cortex (x = -19, y = -41, z = 63, k = 354, BA5). With a statistical threshold set at p < 0.0002, 2 structures showed significant BOLD signal change: right putamen (x = 29, y = -11, z = 6, k = 72) and bilateral thalami (right: x = 23, y = -11, z = 21, k = 29; x = 8, y = -11, z = 9, k = 274; and left: x = -28, y = -32, z = 6, k = 21).

Conclusions The results in this study compare with those in previous studies and suggest that fMRI technology can provide an objective assessment of the pain experience.