Retrospective review of 750 consecutive multilevel cervical spine decompression surgeries performed by a single spine surgeon. To determine the incidence of C5 palsy in a large consecutive series of multilevel cervical spine decompression procedures. Palsy of the C5 nerve is a well-known potential complication of cervical spine surgery with reported rates ranging from 0% to 30%. The etiology remains uncertain but has been attributed to iatrogenic injury during surgery, tethering from shifting of the spinal cord, spinal cord ischemia, and reperfusion injury of the spinal cord. We included patients undergoing multilevel cervical corpectomy, corpectomy with posterior fusion, posterior laminectomy and fusion, and laminoplasty. Exclusion criteria included lack of follow-up data, spinal cord injury preventing preoperative or postoperative motor testing, or surgery not involving the C5 level. Incidence of C5 palsy was determined and compared to determine whether significant differences existed among the various procedures, patient age, sex, revision surgery, preoperative weakness, diabetes, smoking, number of levels decompressed, and history of previous upper extremity surgery. Of the 750 patients, 120 were eliminated on the basis of the exclusion criteria. The 630 patients included in the analysis consisted of 292 females and 338 males. The mean age was 58 years (range, 19-87). The incidence of C5 nerve palsy for the entire group was 42 of 630 (6.7%). The incidence was highest for the laminectomy and fusion group (9.5%), followed by the corpectomy with posterior fusion group (8.4%), the corpectomy group (5.1%), and finally the laminoplasty group (4.8%), although these differences did not reach statistical significance. There was a significantly higher incidence in males (8.6% vs. 4.5%, P = 0.05). Incidence of C5 nerve palsy after cervical spine decompression was 6.7%. This is consistent with previously published studies and represents the largest series of North American patients to date. There is no statistically significant difference in incidence of C5 palsy based on surgical procedure, although there was a trend toward higher rates with laminectomy and fusion.

Riluzole is a sodium-glutamate antagonist that attenuates neurodegeneration in amyotrophic lateral sclerosis (ALS). It has shown favorable results in promoting recovery in pre-clinical models of traumatic spinal cord injury (tSCI) and in early phase clinical trials. This study aimed to evaluate the efficacy and safety of riluzole in acute cervical tSCI. An international, multi-center, prospective, randomized, double-blinded, placebo-controlled, adaptive, Phase III trial (NCT01597518) was undertaken. Patients with American Spinal Injury Association Impairment Scale (AIS) A-C, cervical (C4-C8) tSCI, and <12 h from injury were randomized to receive either riluzole, at an oral dose of 100 mg twice per day (BID) for the first 24 h followed by 50 mg BID for the following 13 days, or placebo. The primary efficacy end-point was change in Upper Extremity Motor (UEM) scores at 180 days. The primary efficacy analyses were conducted on an intention to treat (ITT) and completed cases (CC) basis. The study was powered at a planned enrolment of 351 patients. The trial began in October 2013 and was halted by the sponsor on May 2020 (and terminated in April 2021) in the face of the global COVID-19 pandemic. One hundred ninety-three patients (54.9% of the pre-planned enrolment) were randomized with a follow-up rate of 82.7% at 180 days. At 180 days, in the CC population the riluzole-treated patients compared with placebo had a mean gain of 1.76 UEM scores (95% confidence interval: -2.54-6.06) and 2.86 total motor scores (CI: -6.79-12.52). No drug-related serious adverse events were associated with the use of riluzole. Additional pre-planned sensitivity analyses revealed that in the AIS C population, riluzole was associated with significant improvement in total motor scores (estimate: standard error [SE] 8.0; CI 1.5-14.4) and upper extremity motor scores (SE 13.8; CI 3.1-24.5) at 6 months. AIS B patients had higher reported independence, measured by the Spinal Cord Independence Measure score (45.3 vs. 27.3; d: 18.0 CI: -1.7-38.0) and change in mental health scores, measured by the Short Form 36 mental health domain (2.01 vs. -11.58; d: 13.2 CI: 1.2-24.8) at 180 days. AIS A patients who received riluzole had a higher average gain in neurological levels at 6 months compared with placebo (mean 0.50 levels gained vs. 0.12 in placebo; d: 0.38, CI: -0.2-0.9). The primary analysis did not achieve the predetermined end-point of efficacy for riluzole, likely related to insufficient power. However, on pre-planned secondary analyses, all subgroups of cervical SCI subjects (AIS grades A, B and C) treated with riluzole showed significant gains in functional recovery. The results of this trial may warrant further investigation to extend these findings. Moreover, guideline development groups may wish to assess the possible clinical relevance of the secondary outcome analyses, in light of the fact that SCI is an uncommon orphan disorder without an accepted neuroprotective treatment.

Study Design. Retrospective radiographic analysis. Objective. To retrospectively review a group of patients undergoing anterior cervical discectomy and fusion (ACDF) to determine the relative risk of adjacent level disc degeneration after incorrect needle localization. Summary of Background Data. The needle puncture technique is a well-established method to cause disc degeneration in experimental animal studies. The risk for accelerated degeneration because of needle puncture in humans is unknown. Methods. A retrospective radiographic analysis of 87 consecutive patients after single or 2-level ACDF with anterior plate instrumentation was performed. Perioperative and follow-up radiographs were used to grade disc degeneration according to a previously described scale. Results. Eighty-seven patients were included in the study (36 underwent 1-level ACDF, and 51 underwent 2-level ACDF). Seventy-two had correct needle localization at the level of planned surgery; 15 had incorrect needle localization (1 level above the operative level). There were no differences between the 2 groups in age, sex and length of follow-up. Patients in the incorrectly marked group were statistically more likely to demonstrate progressive disc degeneration with an odds ratio of 3.2. There was no correlation between age and length of follow-up with development of disc degeneration. Conclusion. There is a 3-fold increase in risk of developing adjacent level disc degeneration in incorrectly marked discs after ACDF at short-term follow-up. This may indicate that either needle related trauma or unnecessary surgical dissection contributes to accelerated adjacent segment degeneration.

Osteoporosis is characterized by bony material loss and decreased bone strength leading to a significant increase in fracture risk. Patient-specific quantitative computed tomography (QCT) finite element (FE) models may be used to predict fracture under physiological loading. Material properties for the FE models used to predict fracture are obtained by converting grayscale values from the CT into volumetric bone mineral density (vBMD) using calibration phantoms. If there are any variations arising from the CT acquisition protocol, vBMD estimation and material property assignment could be affected, thus, affecting fracture risk prediction. We hypothesized that material property assignments may be dependent on scanning and postprocessing settings including voltage, current, and reconstruction kernel, thus potentially having an effect in fracture risk prediction. A rabbit femur and a standard calibration phantom were imaged by QCT using different protocols. Cortical and cancellous regions were segmented, their average Hounsfield unit (HU) values obtained and converted to vBMD. Estimated vBMD for the cortical and cancellous regions were affected by voltage and kernel but not by current. Our study demonstrated that there exists a significant variation in the estimated vBMD values obtained with different scanning acquisitions. In addition, the large noise differences observed utilizing different scanning parameters could have an important negative effect on small subregions containing fewer voxels.

Study Design. Retrospective matched-cohort analysis. Objective. To evaluate the change in radiographical parameters in patients undergoing interbody fusion and posterior instrumentation compared with posterior spine fusion (PSF) alone for degenerative scoliosis. Summary of Background Data. Little is known about the effect of lateral interbody fusion (LIF) on sagittal plane correction in the setting of degenerative scoliosis. We performed a retrospective study to investigate these changes compared with PSF. Methods. Between 1997 and 2011, 33 patients had LIF at 181 levels between T8 and L5 vertebrae for the treatment of degenerative scoliosis (mean; 5 ± 2 levels). Of those, 23 patients had additional anterior lumbar interbody fusion (ALIF) at 37 levels between L4 and S1 vertebrae (mean; 1.6 ± 0.5 levels). A 1:1 matched control of patients who underwent PSF was performed. Patients were matched by age, sex, and diagnosis. Clinical and radiographical data were collected and compared between the matched cohorts. Results. Lumbar lordosis (LL) was significantly restored in the LIF ± ALIF compared with PSF cohort (44° ± 14° vs. 36° ± 15°, P = 0.02). The segmental LL over the 102 LIF levels significantly improved from 12°± 10° to 21°± 13° postoperatively (P < 0.0001). However, the change over the 37 ALIF levels was not significant (from 30° ± 15° to 29° ± 9°, P = 0.8). Sagittal plane alignment was improved in the LIF ± ALIF compared with PSF cohort and trended toward but did not reach significance (3.8 ± 3.2 cm vs. 6.2 ± 5.7 cm, P = 0.09). Sacral slope was significantly higher in the LIF ± ALIF compared with PSF cohort (33° ± 11° vs. 28° ± 10°, P = 0.03). Pelvic tilt was lower in the LIF ± ALIF compared with PSF cohort and trended toward but did not reach significance (22° ± 10° vs. 26° ± 10°, P = 0.08). Conclusion. LL and sacral slope had mildly but statistically improved in the interbody fusion cohort compared with PSF cohort. Sagittal alignment and pelvic tilt trended toward but did not reach statistical significance. Segmental LL was improved at LIF levels more than at ALIF levels. Level of Evidence: 3