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Study Design: Prospective cohort study. Objectives: To identify patient trajectories of recovery defined by change in health-related quality of life (HRQOL) following surgery for adolescent idiopathic scoliosis (AIS). To explore possible predictors of trajectory membership. Methods: Adolescent patients scheduled to undergo spinal fusion for AIS were enrolled in the Post-Operative Recovery following Spinal Correction: Home Experience (PORSCHE) study. Responses to the Pediatric Quality of Life Inventory–version 4 (PedsQL–4.0) were collected prior to surgery and 4 to 6 weeks, 3, 6, and 12 months post-operatively. Latent class growth analyses identified patient subgroups based on their unique trajectories of physical health (PH) and psychosocial health (PSH) outcomes using the PedsQL–4.0 subscale scores. Predictors included demographic, clinical, and psychosocial factors. Results: Data from up to 190 patients were included (87.4% female; mean±SD age = 14.6 ± 1.9 years). Three trajectory subgroups were identified for PH and 4 trajectories were found for PSH, with a majority of patients scoring within the established range of healthy adolescents 12 months post-surgery. Increased child and parent pain catastrophizing, child trait anxiety and previous hospitalizations were associated with poorer PH outcomes, whereas increased child and parent pain catastrophizing, child state and trait anxiety, and parent state and trait anxiety were associated with poorer PSH trajectories. Conclusions: The PH and PSH trajectories identified in this study and the factors associated with their membership may inform surgical decision-making for AIS while facilitating patient and family counselling regarding peri-operative recovery and expectations. [ABSTRACT FROM AUTHOR]

The ST1 center is a point defect in diamond with bright fluorescence and a mechanism for optical spin initialization and readout. The center has impressive potential for applications in diamond quantum computing as a quantum bus to a register of nuclear spins. This is because it has an exceptionally high readout contrast, and unlike the well-known nitrogen-vacancy center, it does not have a ground state electronic spin that decoheres the nuclear spins. However, its chemical structure is unknown, and there are large gaps in our understanding of its properties. We present the discovery of ST1 centers in natural diamond. Our experiments identify interesting power dependence of the center’s optical dynamics and reveal new electronic structure. We also present a theory of its electron-phonon interactions, which we combine with previous experiments, to shortlist likely candidates for its chemical structure.

The nitrogen-vacancy (NV) color center in diamond has rapidly emerged as an important solid-state system for quantum information processing. Whereas individual spin registers have been used to implement small-scale diamond quantum computing, the realization of a large-scale device requires the development of an on-chip quantum bus for transporting information between distant qubits. Here, we propose a method for coherent quantum transport of an electron and its spin state between distant NV centers. Transport is achieved by the implementation of spatial stimulated adiabatic Raman passage through the optical control of the NV center charge states and the confined conduction states of a diamond nanostructure. Our models show that, for two NV centers in a diamond nanowire, high-fidelity transport can be achieved over distances of order hundreds of nanometers in timescales of order hundreds of nanoseconds. Spatial adiabatic passage is therefore a promising option for realizing an on-chip spin quantum bus.

The nitrogen-vacancy (NV) center in diamond is a widely utilized system due to its useful quantum properties. Almost all research focuses on the negative charge state (NV−) and comparatively little is understood about the neutral charge state (NV0). This is surprising as the charge state often fluctuates between NV0 and NV− during measurements. There are potentially under-utilized technical applications that could take advantage of NV0, either by improving the performance of NV0 or utilizing NV− directly. However, the fine structure of NV0 has not been observed. Here, we rectify this lack of knowledge by performing magnetic circular dichroism measurements that quantitatively determine the fine structure of NV0. The observed behavior is accurately described by spin-Hamiltonians in the ground and excited states with the ground state yielding a spin-orbit coupling of λ = 2.24 ± 0.05 GHz and a orbital g-factor of 0.0186 ± 0.0005. The reasons why this fine structure has not been previously measured are discussed and strain-broadening is concluded to be the likely reason.

Study Design: Retrospective analysis was performed of a multi-center Canadian Spine Outcomes and Research Network (CSORN) surgical database. Objective: To determine the rate and time to return to work (RTW) based on workload intensity after elective degenerative lumbar spine surgery. Methods: Patients working pre-operatively, aged greater than 18, who underwent a primary one- or two-level elective lumbar spine surgery for degenerative conditions between January 2015 and October 2020 were evaluated. The percentage of patients who returned to work at 1 year and the time to RTW post-operatively were analyzed based on workload intensity. Results: Of the 1290 patients included in the analysis, the overall rate of RTW was 82% at 1 year. Based on workload there was no significant difference in time to RTW after a fusion procedure, with median time to RTW being 10 weeks. For non-fusion procedure, the sedentary group had a statistically significantly quicker time to RTW than the light-moderate (P <.005) and heavy-very heavy (<.027) groups. Conclusions: The rate of RTW ranged between 84% for patients with sedentary work to 77% for patient with a heavy-very heavy workload. Median time to resumption of work was about 10 weeks following a fusion regardless of work intensity. There was more variability following non-fusion surgeries such as laminectomy and discectomy reflecting the patient's job demands. [ABSTRACT FROM AUTHOR]

Study Design: Ambispective cohort study. Objective: Canada has a government-funded universal health care system. The United States utilizes a multitier public and private system. The objective is to investigate differences in clinical outcomes between those surgically treated for lumbar disc herniation in a universal health care and multitier health system. Methods: Surgical lumbar disc herniation patients enrolled in the Canadian Spine Outcome Research Network (CSORN) were compared with the surgical cohort enrolled in the Spine Patients Outcome Research Trial (SPORT) study. Baseline demographics and spine-related patient-reported outcomes (PROs) were compared at 3 months and 1 year post-operatively. Results: The CSORN cohort consisted of 443 patients; the SPORT cohort had 763 patients. Patients in the CSORN cohort were older (46.4 ± 13.5 vs 41.0 ± 10.8, P <.001) and were more likely to be employed (69.5% vs 60.3%, P =.003). The CSORN cohort demonstrated significantly greater rates of satisfaction after surgery at 3 months (87.2% vs 64.8%, P <.0001) and 1 year (85.6% vs 69.6%, P <.0001). Improvements in back and leg pain followed similar trajectories in the two cohorts, but there was less improvement on ODI in the CSORN cohort (P <.01). On multivariable logistic regression, the CSORN cohort was a significant independent predictor of patient satisfaction at 1-year follow-up (P <.001). Conclusions: Despite less improvement on ODI, patients enrolled in CSORN, as part of a universal health care system, reported higher rates of satisfaction at 3 months and 1 year post-operatively compared to patients enrolled within a multitier health system. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort. Objectives: To compare outcomes of minimally invasive surgery (MIS) vs open surgery (OPEN) for lumbar spinal stenosis (LSS) in patients with diabetes. Methods: Patients with diabetes who underwent spinal decompression alone or with fusion for LSS within the Canadian Spine Outcomes and Research Network (CSORN) database were included. MIS vs OPEN outcomes were compared for 2 cohorts: (1) patients with diabetes who underwent decompression alone (N = 116; MIS n = 58 and OPEN n = 58), (2) patients with diabetes who underwent decompression with fusion (N = 108; MIS n = 54 and OPEN n = 54). Modified Oswestry Disability Index (mODI) and back and leg pain were compared at baseline, 6–18 weeks, and 1-year post-operation. The number of patients meeting minimum clinically important difference (MCID) or minimum pain/disability at 1-year was compared. Results: MIS approaches had less blood loss (decompression alone difference 100 mL, P =.002; with fusion difference 244 mL, P <.001) and shorter length of stay (LOS) (decompression alone difference 1.2 days, P =.008; with fusion difference 1.2 days, P =.026). MIS compared to OPEN decompression with fusion had less patients experiencing adverse events (AEs) (difference 13 patients, P =.007). The MIS decompression with fusion group had lower 1-year mODI (difference 14.5, 95% CI [7.5, 21.0], P <.001) and back pain (difference 1.6, 95% CI [.6, 2.7], P =.002) compared to OPEN. More patients in the MIS decompression with fusion group exceeded MCID at 1-year for mODI (MIS 75.9% vs OPEN 53.7%, P =.028) and back pain (MIS 85.2% vs OPEN 70.4%, P =.017). Conclusions: MIS approaches were associated with more favorable outcomes for patients with diabetes undergoing decompression with fusion for LSS. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort study. Objective: We evaluated the effectiveness of minimally invasive (MIS) tubular discectomy in comparison to conventional open surgery among patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN). Methods: We performed an observational analysis of data that was prospectively collected. We implemented Minimum Clinically Important Differences (MCIDs), and we adjusted for potential confounders with multiple logistic regression. Adverse events were collected according to the Spinal Adverse Events Severity (SAVES) protocol. Results: Three hundred thirty-nine (62%) patients underwent MIS tubular discectomy and 211 (38%) underwent conventional open discectomy. There were no significant differences between groups for improvement of leg pain and disability, but the MIS technique was associated with reduced odds of achieving the MCID for back pain (OR 0.66, 95% CI 0.44 to 0.99, P < 0.05). We identified statistically significant differences in favor of MIS for each of operating time (MIS mean (SD) 72.2 minutes (30.0) vs open 93.5 (40.9)), estimated blood loss (MIS 37.9 mL (36.7) vs open 76.8 (71.4)), length of stay in hospital (MIS 73% same-day discharge vs open 40%), rates of incidental durotomy (MIS 4% vs open 8%), and wound-related complications (MIS 3% vs open 9%); but not for overall rates of reoperation. Conclusions: Open and MIS techniques yielded similar improvements of leg pain and disability at up to 12 months of follow-up, but MIS patients were less likely to experience improvement of associated back pain. Small differences favored MIS for operating time, blood loss, and adverse events but may have limited clinical importance. [ABSTRACT FROM AUTHOR]