Timing of Recovery After Surgery for Patients With Degenerative Cervical Myelopathy: An Observational Study From the Canadian Spine Outcomes and Research Network.

BACKGROUND: The time course over which postoperative neurological recovery occurs after surgery for degenerative cervical myelopathy occurs is poorly understood. OBJECTIVE: To determine the time point at which patients experience significant neurological improvement. METHODS: We reviewed data from an ongoing prospective multicenter cohort study. We measured neurological function at 3 months, 1 year, and 2 years after surgery using the modified Japanese Orthopedic Association (mJOA) scale. We implemented minimal clinical important differences (MCIDs) to guide interpretation of mJOA scores, and we used 1-way analysis of variance to compare changes between follow-up intervals. RESULTS: Among 330 patients, the mean overall mJOA improved from 12.9 (SD 2.6) to 14.6 (SD 2.4) at 3 months, 14.7 (SD 2.4) at 1 year, and 14.8 (SD 2.5) at 2 years. The difference in means was statistically significant (P < .01) at the interval from baseline to 3 months postoperatively, but not from 3 months to 1 year or 1 year to 2 years. The MCID was reached by 161 patients at 3 months, 32 more at 1 year, and 15 more at 2 years, with a statistically significant difference only at 3 months. Patients with moderate or severe disease reached the MCID more frequently than those with mild disease. CONCLUSION: Among patients who underwent surgery for degenerative cervical myelopathy, most significant neurological improvement occurred by 3 months after surgery. These findings will facilitate valid discussions about postoperative expectations during shared clinical decision making between patients and their surgeons.

Spinal pathology and outcome post-THA: does segment of arthrodesis matter?

INTRODUCTION: The presence of lumbar spine arthrodesis (SA) is associated with abnormal spinopelvic characteristics and inferior outcome post total hip arthroplasty (THA). However, whether patients with upper segment SA are also at increased risk of complications is unknown. This study aims to (1) determine if upper segment SA is associated with inferior THA outcomes; (2) assess spino-pelvic characteristics; and (3) test whether static or dynamic spinopelvic characteristics correlate with outcome post-THA. MATERIALS AND METHODS: In this retrospective, case-matched, cohort study from a tertiary referral centre, 40 patients (59 hips) that had undergone both THA and any level of spinal arthrodesis (49 THA-Lumb and 10 THA-Cerv) were compared with 41 patients (59 hips) who had THA-only without known spinal pathology. Spino-pelvic characteristics [including severity of Degenerative-Disc-Disease (DDD); spinal balance and stiffness] and outcome, including patient reported outcome measures (PROMs), at minimum of 1-year post-THA were assessed. RESULTS: THA-Lumb and THA-Cerv groups had greater number of complications and inferior hip and spinal PROMs compared to THA-Only (p < 0.001). Similar spinopelvic characteristics were seen between the THA-Cerv and THA-Lumb, which were significantly different to the THA-only group. The presence of DDD and unbalanced or stiff spine was associated with increased dislocation and inferior PROMs in the whole cohort. CONCLUSIONS: THA in the presence of SA, regardless of level, is associated with inferior outcomes and an increased risk for dislocation. The presence of a SA is associated with increased risk of adverse spinopelvic characteristics. Such characteristics were strongly associated with increased dislocation-risk and inferior PROMs. It is likely that these adverse characteristics are the most important adverse predictor, rather than segment of SA per se.

2018 Frank Stinchfield Award: Spinopelvic Hypermobility Is Associated With an Inferior Outcome After THA: Examining the Effect of Spinal Arthrodesis.

BACKGROUND: Many patients undergo both THA and spinal arthrodesis, and those patients may not fare as well as those who undergo one procedure but not the other. The mechanisms of how spinal arthrodesis affects patient function after THA remain unclear. QUESTIONS/PURPOSES: The aims of our study were to (1) determine how patient-reported outcome measures (PROMs), including the Oxford hip score as well as dislocations and complications compare after THA between patients with and without spinal arthrodesis; (2) characterize sagittal pelvic changes in these patients that occur when moving between different functional positions and test for differences between patients with and without spinal arthrodesis; and (3) assess whether differences in sagittal pelvic dynamics are associated with PROMs, complications, and dislocations after THA. METHODS: In this case-control study, we identified 42 patients (60 hips) who had undergone both THA and spinal arthrodesis between 2002 and 2016 and who were available for followup at a minimum of 12 months (mean, 6 ± 5 years) after the later of the two procedures. These cases were case-control-matched for age, gender, and body mass index with 42 patients (60 hips) who underwent only THA and had no known spinal pathology. All patients completed PROMs, including the Oxford hip score, and underwent four radiographs of the pelvis and spinopelvic complex in three positions (supine, standing, and deep-seated). Cup orientation and various spinopelvic parameters, including pelvic tilt and pelvic-femoral angle, were measured. The difference in pelvic tilt between standing and seated allowed for patient classification based on spinopelvic mobility into normal (± 10°-30°), stiff (< ± 10°) or hypermobile (> ± 30°) groups. RESULTS: Compared with the THA-only group, the THA-spinal arthrodesis group had inferior PROMs (Oxford hip score, 33 ± 10 versus 43 ± 6; p < 0.001) and more surgery-related complications (such as dislocation, loosening, periprosthetic fracture or infection, psoas irritation) (12 versus 3; p = 0.013), especially dislocation (5 versus 0; p = 0.023). We detected no difference in change of pelvic tilt between supine and standing positions between the groups. When standing, patients undergoing THA-spinal arthrodesis had greater pelvic tilt (25° ± 11° versus 17° ± 8°; p < 0.001) and the hip was more extended (193° ± 22° versus 185° ± 30°; p = 0.012). We found that patients undergoing THA-spinal arthrodesis were more likely to have spinopelvic hypermobility (12 of 42 versus three of 42; odds ratio, 5.2; p = 0.02) with anterior tilting of the pelvis. Of all biomechanical parameters, only spinopelvic hypermobility was associated with inferior PROMs (Oxford hip score, 35 ± 9 versus 40 ± 7 in normal mobility; p = 0.049) and was also present in dislocating hips that underwent revision despite acceptable cup orientation. CONCLUSIONS: In patients with spinal arthrodesis who have undergone THA, spinopelvic hypermobility is associated with inferior outcomes, including hip instability. Spinopelvic hypermobility should be routinely assessed because these patients may have a narrow zone of optimum cup orientation that would require new technology to define and assist the surgeon in obtaining it.Level of Evidence Level III, therapeutic study.

The Use of a Self-Administered Questionnaire to Reduce Consultation Wait Times for Potential Elective Lumbar Spinal Surgical Candidates: A Prospective, Pragmatic, Blinded, Randomized Controlled Quality Improvement Study.

BACKGROUND: In a public health-care system, patients often experience lengthy wait times to see a spine surgeon for consultation, and most patients are found not to be surgical candidates, thereby prolonging the wait time for those who are. The aim of this study was to evaluate whether a self-administered 3-item questionnaire (3IQ) could reprioritize consultation appointments and reduce wait times for lumbar spinal surgical candidates. METHODS: This prospective, pragmatic, blinded, randomized controlled quality improvement study was conducted at a single Canadian academic health-care center. This study enrolled 227 consecutive eligible participants with an elective lumbar condition who were referred for consultation with a spine surgeon. All participants were mailed the 3IQ after their referral was received. Patients were randomized into the intervention group, in which leg-dominant pain reported on the 3IQ resulted in an upgrade in priority to be seen, or into the control group, in which no change to wait-list priority occurred. The main outcome measured was time to consultation for participants who were deemed surgical candidates following consultation. RESULTS: There were no significant differences between groups with regard to demographics, overall group wait times, proportion of surgical candidates, or disability. A total of 33 patients were deemed surgical candidates after consultation. The median wait from referral to consultation was shorter for the 16 surgical candidates in the intervention group (2.5 months; interquartile range [IQR]: 2.0 to 4.8 months) compared with the 17 surgical candidates in the control group (4.5 months; IQR: 3.4 to 6.9 months; p = 0.090). The odds of seeing a surgical candidate within the acceptable time frame of 3 months were 5.4 times greater (95% confidence interval: 1.2 to 24.5 times; p = 0.024) in the intervention group. CONCLUSIONS: The use of a simple, self-administered questionnaire to reprioritize referrals resulted in shorter consultation wait times for patients who required a surgical procedure and significantly increased the number of surgical candidates seen within the acceptable time frame. It may be valuable to consider adding the 3IQ to clinical care practices to better triage these patients on waiting lists.

Activities performed and treatments conducted before consultation with a spine surgeon: are patients and clinicians following evidence-based clinical practice guidelines?

BACKGROUND CONTEXT: Clinical practice guidelines (CPGs) are designed to ensure that evidence-based treatment is easily put into action. Whether patients and clinicians follow these guidelines is equivocal. PURPOSE: The objectives of this study were to examine how many patients complaining of low back pain (LBP) underwent evidence-based medical interventional treatment in line with CPG recommendations before consultation with a spine surgeon, and to evaluate any associations between adherence to CPG recommendations and baseline factors. STUDY DESIGN/SETTING: This is a cross-sectional cohort analysis at a tertiary care center. PATIENT SAMPLE: A total of 229 patients were referred for surgical consultation for an elective lumbar spinal condition. OUTCOME MEASURES: The outcome measures include the number of CPG-recommended treatments undertaken by patients at or before the time of referral, the validated pain score, the EuroQol-5D (EQ-5D) health status, and the Oswestry Disability Index (ODI) score. METHODS: Questionnaires assessing demographic and functional characteristics as well as overall health care use were sent to patients immediately after their referral was received by the surgeon's office. RESULTS: Medications were the most common modality before consultation (74.2% of patients), of which 46.3% received opioids. The number of medications taken was significantly related to a higher ODI score (R=0.23, p=.0004), a higher pain score (R=0.15, p=.026), and a lower EQ-5D health status (R=-0.15, p=.024). In contrast, a lower pain score (7.2 vs. 7.7, p=.037) and a lower ODI score (26.6 vs. 29.9, p=.0023) were associated with performing adequate amounts of exercise. There was a significant association between lower numbers of treatments received and higher numerical pain rating scores (R=-0.14, p=.035). The majority (61.1%) of patients received two or less forms of treatment. CONCLUSIONS: Evidence-based medical interventional treatments for patients with LBP are not being taken advantage of before spine surgery consultation. If more patients were to undertake CPG-endorsed conservative modalities, it may result in fewer unnecessary referrals from primary care physicians, and patients might not deteriorate as much while lingering on long wait lists. Further studies incorporating knowledge translation or health system pathway changes are necessary.

Host-selected mutations converging on a global regulator drive an adaptive leap towards symbiosis in bacteria.

Host immune and physical barriers protect against pathogens but also impede the establishment of essential symbiotic partnerships. To reveal mechanisms by which beneficial organisms adapt to circumvent host defenses, we experimentally evolved ecologically distinct bioluminescent Vibrio fischeri by colonization and growth within the light organs of the squid Euprymna scolopes. Serial squid passaging of bacteria produced eight distinct mutations in the binK sensor kinase gene, which conferred an exceptional selective advantage that could be demonstrated through both empirical and theoretical analysis. Squid-adaptive binK alleles promoted colonization and immune evasion that were mediated by cell-associated matrices including symbiotic polysaccharide (Syp) and cellulose. binK variation also altered quorum sensing, raising the threshold for luminescence induction. Preexisting coordinated regulation of symbiosis traits by BinK presented an efficient solution where altered BinK function was the key to unlock multiple colonization barriers. These results identify a genetic basis for microbial adaptability and underscore the importance of hosts as selective agents that shape emergent symbiont populations.

Precise control of miR-125b levels is required to create a regeneration-permissive environment after spinal cord injury: a cross-species comparison between salamander and rat.

Most spinal cord injuries lead to permanent paralysis in mammals. By contrast, the remarkable regenerative abilities of salamanders enable full functional recovery even from complete spinal cord transections. The molecular differences underlying this evolutionary divergence between mammals and amphibians are poorly understood. We focused on upstream regulators of gene expression as primary entry points into this question. We identified a group of microRNAs (miRNAs) that are conserved between the Mexican axolotl salamander (Ambystoma mexicanum) and mammals but show marked cross-species differences in regulation patterns following spinal cord injury. We found that precise post-injury levels of one of these miRNAs (miR-125b) is essential for functional recovery, and guides correct regeneration of axons through the lesion site in a process involving the direct downstream target Sema4D in axolotls. Translating these results to a mammalian model, we increased miR-125b levels in the rat through mimic treatments following spinal cord transection. These treatments downregulated Sema4D and other glial-scar-related genes, and enhanced the animal's functional recovery. Our study identifies a key regulatory molecule conserved between salamander and mammal, and shows that the expression of miR-125b and Sema4D must be carefully controlled in the right cells at the correct level to promote regeneration. We also show that these molecular components of the salamander's regeneration-permissive environment can be experimentally harnessed to improve treatment outcomes for mammalian spinal cord injuries.