Retrospective review.
To assess the impact of Body Mass Index (BMI) on patient-reported outcome measures (PROMs) after cervical disc replacement (CDR).
BMI may affect PROMs after spine surgery.
...Primary CDR recipients for herniated disc(s) with BMI <40 were retrospectively selected from a single-surgeon registry. Cohorts were divided into non-obese (BMI <30) and obese (BMI ≥30). Intercohort in-hospital complication rates were compared through independent samples t tests. Pre/postoperative PROMs were compared between cohorts through multivariable regression accounting for demographic differences. Final follow-up dates between patients averaged 11.8 ± 9.3 months. PROMs assessed included Patient-reported Outcomes Measurement Information System-Physical Function, Neck Disability Index, Visual Analog Scale-Neck, Visual Analog Scale-Arm, and the 9-item Patient Health Questionnaire. Improvements in PROMs were evaluated and compared at each follow-up within cohorts through paired t tests. The magnitude of improvement in PROMs from preoperative baseline at 6-week follow-up (∆PROM-6W) and final follow-up (∆PROM-FF) along with achievement rates of minimum clinically important differences were compared between cohorts through multivariable regression accounting for demographic differences.
Of 153 patients, 53 patients were noted as obese. Demographic differences included age, prevalence of hypertension and diabetes, and comorbidity burden scores (P ≤ 0.011, all). No significant variations in in-hospital complications were found. The non-obese cohort demonstrated improvements in all PROMs at 6 weeks and final follow-up periods (P ≤ 0.005, all). The obese cohort demonstrated improvements in all postoperative PROMs besides 9-item Patient Health Questionnaire at 6 weeks (P ≤ 0.015, all). After accounting for age and comorbidity variations, there were no significant intercohort differences in raw PROM scores, ∆PROM-6W, ∆PROM-FF, or minimum clinically important difference achievement rates.
Regardless of BMI, patients experience significant improvements in physical function, disability, pain, and mental health after CDR for disc herniation. Patients with obesity do not suffer inferior patient-perceived outcomes after CDR. These findings may help surgeons counsel patients in the preoperative period.
Patients with a prolonged preoperative symptom duration (PSD) in the setting of cervical disk herniation (DH) may suffer inferior outcomes after surgical intervention. Comparison between anterior ...cervical diskectomy and fusion (ACDF) versus cervical disk arthroplasty (CDA) in this at-risk population has not yet been conducted.
Patients undergoing ACDF or CDA for DH with a PSD > 180 days were selected. Six-week (6W) and final follow-up (FF) patient-reported outcome measures (PROMs) as well as magnitude of postoperative improvements (∆PROM) were compared between cohorts using multivariable linear regression. Intercohort achievement rates of minimal clinically important difference (MCID) in each PROM were compared.
Seventy-seven of 190 patients were in the CDA cohort. 6W Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF) was superior in the CDA cohort. The ACDF cohort demonstrated notable improvements in the 6W Neck Disability Index (NDI), visual analog scale-neck pain (VAS-N), visual analog scale-arm pain (VAS-A), and 9-item Patient Health Questionnaire (PHQ-9). The CDA cohort demonstrated notable improvements in 6W PROMIS-PF, NDI, VAS-N, and VAS-A. FF VAS-A was better in the CDA cohort. The ACDF cohort demonstrated notable improvements in FF PROMIS-PF, NDI, VAS-N, and VAS-A. The CDA cohort demonstrated notable improvements in all FF PROMs. ∆PROM-6W in PROMIS-PF was greater in the CDA cohort.
Patients with prolonged PSD due to cervical DH demonstrated notable improvements in physical function, disability, pain, and mental health regardless of fusion versus arthroplasty techniques. Accounting for demographic variations, patients undergoing CDA demonstrated a greater magnitude of improvement and superior scores in physical function at the first postoperative follow-up. Rates of clinically tangible improvements in PROMs did not markedly vary by surgical procedure. Patients undergoing CDA may perceive greater early improvements to physical function compared with patients undergoing ACDF for prolonged PSD due to DH.
Retrospective review.
To examine the effect of baseline Veterans RAND-12 (VR-12) Mental Composite Score (MCS) on clinical outcomes in patients undergoing cervical disk replacement (CDR) for herniated ...disk.
Few studies in spine surgery have evaluated the impact of preoperative VR-12 MCS on postoperative outcomes in patients undergoing CDR.
Patients undergoing CDR for herniated disk were separated into 2 cohorts based on the VR-12 MCS standardized mean: VR-12 MCS<50 (worse mental health) and VR-12 MCS≥50 (better mental health). Patient-reported outcome measures of VR-12 MCS, VR-12 Physical Composite Score, Short Form-12 (SF-12) MCS, SF-12 Physical Composite Score, Patient-Reported Outcomes Measurement Information System Physical Function, Patient Health Questionnaire-9 (PHQ-9), Visual Analog Scale (VAS) Neck Pain, VAS Arm Pain, and Neck Disability Index were collected at preoperative and up to 2-year postoperative time points.
In all, 109 patients were identified, with 50 patients in the worse mental health cohort. The worse mental health cohort reported inferior patient-reported outcome measures in all domains at preoperative, 6-week postoperative, and final postoperative time points. For 6-week postoperative improvement, the worse mental health cohort reported greater improvement for VR-12 MCS, SF-12 MCS, and PHQ-9. For final postoperative improvement, the worse mental health cohort reported greater improvement in VR-12 MCS and SF-12 MCS. Minimum clinically important difference achievement rates were higher in the worse mental health cohort for VR-12 MCS, SF-12 MCS, and PHQ-9.
Patients undergoing cervical disk replacement for herniated disk with worse baseline mental health reported inferior clinical outcomes in mental health, physical function, pain, and disability outcomes throughout the postoperative period. Patients with worse baseline mental health demonstrated greater clinically meaningful improvement in mental health. In cervical disk replacement patients, those with worse baseline mental health may report inferior postoperative clinical outcomes but experience greater rates of tangible improvement in mental health.
Retrospective study.
To characterize an experienced single surgeon learning curve for cervical disk replacement (CDR).
A single surgeon learning curve has not been established for CDR.
Patients ...undergoing CDR were included. The cumulative sum of operative time was utilized to separate cases into 3 phases: learning, practicing, and mastery. Demographics, perioperative characteristics, complications, patient-reported outcomes (PROs), and radiographic outcomes were collected preoperatively and up to 1 year postoperatively. PROs included Patient-reported Outcomes Measurement Information System Physical Function, 12-item Short Form-12 Physical Component Score, 12-item Short Form-12 Mental Component Score, visual analog scale (VAS) arm, VAS neck, Neck Disability Index. Radiographic outcomes included segmental angle/segmental range of motion/C2-C7 range of motion. Minimum clinically important difference achievement was determined through a comparison of previously established values.
A total of 173 patients were identified, with 14 patients in the learning phase, 42 patients in the practicing phase, and 117 patients in the mastery phase. Mean operative time and mean postoperative day 0 narcotic consumption were significantly higher in the learning phase. The preoperative segmental angle was significantly lower for the learning phase, though these differences were eliminated at the final postoperative time point. Patients in the learning phase reported worse improvement to 6-week postoperative, final postoperative, and worse overall final postoperative VAS Arm scores compared with practicing and mastery phases.
For an experienced spine surgeon, the learning phase for CDR was estimated to span 14 patients. During this phase, patients demonstrated longer operative times, higher postoperative narcotic consumption, and worse postoperative VAS Arm scores. Radiographically, no postoperative differences were noted between different phases of mastery. This single surgeon learning curve demonstrates that CDR may be performed safely and with comparable outcomes by experienced spine surgeons despite decreased operative efficiency in the learning phase.
Retrospective review.
To determine postoperative clinical outcomes in patients undergoing minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF) for isthmic spondylolisthesis (IS).
...Few studies have examined the postoperative clinical trajectory in patients undergoing MIS-TLIF specifically for IS.
Patients were separated into two cohorts based on the previously defined Visual Analog Scale (VAS) back pain (BP) for severe pain: VAS-BP <7 and VAS-BP ≥7. Patient-reported outcome measures (PROMs) of Patient-Reported Outcomes Measurement Information System-physical function (PF), 12-item Short Form (SF-12) Physical/Mental Component Score, Patient Health Questionnaire-9, VAS-BP, VAS leg pain, and Oswestry Disability Index were collected preoperatively and up to 2-year postoperatively. Minimum clinically important difference (MCID) was calculated through previously defined thresholds.
A total of 160 patients were recorded, with 58 patients in the VAS-BP <7 cohort. The VAS-BP <7 cohort demonstrated significant improvement in all PROMs at one or more postoperative time points. The VAS-BP ≥7 demonstrated significant improvement at 3 or more postoperative time points in all PROMs except for SF-12 Mental Component Score. The VAS-BP <7 cohort reported significantly superior preoperative and postoperative PROMs in all domains, except for SF-12 Physical Component Score. The VAS-BP ≥7 cohort had higher MCID achievement rates at one or more time points in multiple PROMs.
Patients undergoing MIS-TLIF for IS demonstrated significant postoperative improvement in PF, mental function, pain, and disability outcomes independent of preoperative severity of BP. Patients with lower preoperative BP demonstrated superior outcomes in PF, mental function, pain, and disability. However, patients with greater preoperative BP achieved higher rates of MCID in mental function, BP, and disability outcomes. Patients with greater severity of preoperative BP undergoing MIS-TLIF for IS may experience greater rates of clinically relevant improvement in mental function, BP, and disability outcomes.
Retrospective cohort study.
To assess the impact of preoperative symptom duration (PSD) on patient-reported outcome measures (PROMs) after minimally invasive (MIS) transforaminal lumbar interbody ...fusion (TLIF) for degenerative spondylolisthesis (DSpond).
A prolonged duration of preoperative symptoms may implicate inferior long-term outcomes postsurgery. Prior studies of lumbar fusion recipients are limited by the inclusion of heterogeneous populations.
A single-surgeon registry was retrospectively queried for privately insured patients who had undergone primary, elective, single-level MIS-TLIF for DSpond with a recorded symptom start date. Cohorts were formed by PSD: shorter duration (PSD <1 y) or greater duration (GD; PSD ≥1 y). PROMs evaluated included Patient-reported Outcomes Measurement Information System-Physical Function, Oswestry Disability Index, Visual Analog Scale-Back, Visual Analog Scale-Leg, and 9-item Patient Health Questionnaire. The magnitude of PROM (∆PROM) improvement from preoperative baseline to 6 weeks and final follow-up (∆PROM-FF) were compared between cohorts. Intercohort achievement rates of a minimum clinically important difference in each PROM were compared.
A total of 133 patients included 85 patients with GD cohort. There were no significant differences in pre hoc demographics and perioperative characteristics between cohorts, as well as preoperative, 6-week, or final follow-up PROMs between cohorts. Both cohorts demonstrated significant improvement in all PROMs at 6 weeks and final follow-up (P ≤ 0.049, all). There were no significant intercohort differences demonstrated in minimum clinically important difference achievement rates, ∆PROM-6W, or ∆PROM-FF in any PROM.
Regardless of the symptom duration before MIS-TLIF for DSpond, patients demonstrate significant improvement in physical function, pain, disability, and mental health. Patients with a GD of preoperative symptoms did not report inferior scores in any PROM domain. Patients with a GD of preoperative symptoms did not suffer inferior rates of clinically meaningful improvement after surgical intervention. These findings should be considered when counseling patients before surgical intervention for DSpond.
Nutrients are not only organic compounds fueling bioenergetics and biosynthesis, but also key chemical signals controlling growth and metabolism. Nutrients enormously impact the production of ...reactive oxygen species (ROS), which play essential roles in normal physiology and diseases. How nutrient signaling is integrated with redox regulation is an interesting, but not fully understood, question. Herein, we report that superoxide dismutase 1 (SOD1) is a conserved component of the mechanistic target of rapamycin complex 1 (mTORC1) nutrient signaling. mTORC1 regulates SOD1 activity through reversible phosphorylation at S39 in yeast and T40 in humans in response to nutrients, which moderates ROS level and prevents oxidative DNA damage. We further show that SOD1 activation enhances cancer cell survival and tumor formation in the ischemic tumor microenvironment and protects against the chemotherapeutic agent cisplatin. Collectively, these findings identify a conserved mechanism by which eukaryotes dynamically regulate redox homeostasis in response to changing nutrient conditions.
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•SOD1 is a conserved effector of mTORC1 signaling in eukaryotic cells•Nutrients restrain SOD1 through mTORC1-dependent phosphorylation to promote growth•Starvation stimulates SOD1 activity to prevent oxidative damage and enhance survival•SOD1 enhances cancer cell survival and chemoresistance in ischemic microenvironment
Tsang et al. show that SOD1 phosphorylation by mTOR provides a dynamic mechanism for eukaryotic cells to respond to changing nutrient conditions. It permits rapid growth in rich nutrients, while it confers resistance to oxidative stress during starvation. This mechanism contributes to cancer cell survival and chemoresistance in the ischemic microenvironment.
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