Correlation of mental health with physical function, pain, and disability following anterior lumbar interbody fusion.

BACKGROUND: Studies have demonstrated the influence of preoperative mental health on outcomes following spine surgery, but prior literature has not assessed the influence of mental health at time of outcome survey collection. METHODS: Patients who underwent elective anterior lumbar interbody fusion (ALIF) were identified from a prospective registry. Patient-reported outcomes (PROs) were collected preoperatively and up to 1 year postoperatively. Mental health measures studied included 12-item Short Form (SF-12) Mental Component Score (MCS) and Patient Health Questionnaire-9 (PHQ-9). Patient-Reported Outcome Measurement Information System-Physical Function (PROMIS-PF), SF-12 Physical Component Score (PCS), visual analog scale (VAS) back and leg pain, and Oswestry Disability Index (ODI) were compared to the mental health measures by Pearson's correlation tests. RESULTS: A total of 166 patients were included. SF-12 MCS demonstrated positive correlation to PROMIS-PF preoperatively (|r|= 0.379) and at 6 weeks (|r|= 0.387) (p ≤ 0.016, all). SF-12 MCS demonstrated negative correlation to VAS back at 6 months (|r|= 0.359), VAS leg at 6 weeks (|r|= 0.475) and 12 weeks (|r|= 0.422), and ODI up to 6 months postoperatively (|r|= 0.417-0.526) (p ≤ 0.037, all). PHQ-9 negatively correlated with PROMIS-PF at all periods studied (|r|= 0.425-0.587) and SF-12 PCS up to 6 months postoperatively (|r|= 0.367-0.642) (p ≤ 0.016, all). PHQ-9 positively correlated to VAS back at 6 weeks (|r|= 0.408) and 6 months (|r|= 0.411), VAS leg at 6 weeks (|r|= 0.344), and ODI up to 6 months postoperatively (|r|= 0.321-0.669) (p ≤ 0.034, all). CONCLUSION: Inferior mental health correlated with inferior pain, function, and disability scores at one or more periods postoperatively. This finding was most consistent for correlation between mental health scores and disability. Optimization of mental health may positively influence outcomes, especially regarding disability, following ALIF.

Establishing minimum clinically important difference for patient-reported outcome measures in patients undergoing lateral lumbar interbody fusion.

BACKGROUND: The minimum clinically important difference (MCID) has not been established in lateral lumbar interbody fusion (LLIF). Our study aims to establish MCID for patient-reported outcome measures (PROMs) of physical function and pain for LLIF through anchor-based and distribution-based approaches. METHODS: Patients undergoing LLIF with preoperative and 6-month postoperative Oswestry Disability Index (ODI) scores were identified. PROMs of Patient-Reported Outcome Measurement Information System Physical Function (PROMIS-PF), 12-Item Short Form Physical Component Score (SF-12 PCS), Veterans RAND 12-Item Short Form Physical Component Score (VR-12 PCS), visual analog scale (VAS) back, and VAS leg were collected at preoperative and 6-month postoperative time points. Anchor-based MCID calculations were average change, minimal detectable change, change difference, receiver operating characteristic curve, and cross-sectional analysis using ODI as the anchor. Distribution-based calculations were standard error of measurement, reliable change index, effect size, and 0.5 ∗ ΔSD. RESULTS: Fifty patients were included. Anchor-based approaches MCID ranges were PROMIS-PF 1.1-9.6, SF-12 PCS 6.4-16.5, VR-12 PCS 5.9-12.9, VAS Back 1.4-4.6, and VAS Leg 1.3-4.3. The area under curve for receiver operating characteristics (ROC) analysis ranged from 0.63 to 0.71. Distribution-based MCID ranges were PROMIS-PF 1.4-4.5, SF-12 PCS 1.9-12.7, VR-12 PCS 2.0-6.6, VAS Back 0.4-1.4, and VAS Leg 0.5-2.0. CONCLUSION: MCID thresholds varied widely depending on the calculation method. The closest to (0,1) ROC approach was the most clinically appropriate MCID calculation. The corresponding MCID values for LLIF were PROMIS-PF at 7.8, SF-12 PCS at 6.4, VR-12 PCS at 9.3, VAS Back at 4.6, and VAS Leg at 4.3.

Poor mental health scores correlate with inferior outcomes following minimally invasive transforaminal lumbar interbody fusion.

BACKGROUND: Limited spine literature has studied the strength of association of mental health with other outcomes at time of survey collection. We aim to evaluate the degree to which mental health correlates with outcomes in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) at several postoperative periods. METHODS: Patients having undergone elective MIS-TLIF were searched within a retrospective single-surgeon database. Five hundred eighty-five patients were included. Patient-reported outcomes (PROs) including Patient-Reported Outcome Measurement Information System Physical Function (PROMIS PF), 12-item Short Form Physical Component Score (SF-12 PCS) and Mental Component Score (SF-12 MCS), Patient Health Questionnaire-9 (PHQ-9), Visual Analog Scale (VAS) back and leg pain, and Oswestry Disability Index (ODI) scores were collected preoperatively and at 6-week, 12-week, 6-month, 1-year, and 2-year periods. Pearson's correlation tests were used to evaluate the association between both SF-12 MCS and PHQ-9 scores to other PROs at each period. RESULTS: SF-12 MCS correlated with PROMIS PF (|r|= 0.308-0.531), SF-12 PCS (|r|= 0.207-0.328), VAS back (|r|= 0.279-0.474), VAS leg (|r|= 0.178-0.395), and ODI (|r|= 0.450-0.538) at all time points (P ≤ 0.021, all) except for preoperative SF-12 PCS and 1-year VAS leg. PHQ-9 correlated with PROMIS PF (|r|= 0.366-0.701), SF-12 PCS (|r|= 0.305-0.568), VAS back (|r|= 0.362-0.714), VAS leg (|r|= 0.319-0.694), and ODI (|r|= 0.613-0.784) at all periods (P < 0.001, all). CONCLUSION: Poor mental health scores were correlated with lower physical function, elevated pain scores, and higher disability. PHQ-9 scores demonstrated stronger correlation in all relationships compared to SF-12 MCS. Optimization of patient mental health may lead to improved patient perception regarding function, pain, and disability following MIS-TLIF.

Recovery ratios and minimum clinically important difference for clinical outcomes in workers' compensation recipients undergoing MIS-TLIF versus ALIF.

BACKGROUND: There is a scarcity of literature that examines clinical outcomes through patient-reported outcomes (PROs), minimum clinically important difference (MCID), and recovery ratios (RR) for workers' compensation (WC) recipients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) versus anterior lumbar interbody fusion (ALIF). METHODS: WC claimants undergoing MIS-TLIF versus ALIF were propensity score matched to account for demographic differences. Demographics, perioperative characteristics, and PROs were collected. PROs of Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), 12-Item Short Form Physical Composite Score (SF-12 PCS), Visual Analog Scale (VAS) back, VAS leg, and Oswestry Disability Index (ODI) were collected at preoperative and postoperative time points. MCID achievement was determined through comparison to values in literature. RR was calculated as the difference between postoperative and preoperative PROs over potential improvement. Comparison between surgical techniques was through non-parametric inferential statistics. RESULTS: Eighty-four WC claimants, with 50 patients undergoing MIS-TLIF, were identified after propensity score matching. ALIF patients had higher estimated blood loss. MIS-TLIF patients had higher postoperative day (POD) 0 VAS pain and POD 0 + 1 narcotic consumption. Patients undergoing either MIS-TLIF or ALIF reported significant improvement in pain and disability. ALIF patients reported significant improvement in physical function. ALIF patients reported superior 1-year PROMIS-PF, 6-week SF-12 PCS, 6-month VAS back, and 12-week VAS leg. No significant differences in MCID achievement rates were noted between cohorts. ALIF patients had higher RR in 6-week and 1-year PROMIS-PF and 6-week SF-12 PCS. CONCLUSION: Workers' compensation claimants undergoing either MIS-TLIF or ALIF reported significant improvement in pain and disability. ALIF patients reported superior postoperative physical function and pain. ALIF patients had higher recovery ratios in physical function. Workers' compensation claimants undergoing ALIF may experience greater physical function recovery and superior clinical outcomes in physical function and pain.

Poor patient-reported mental health correlates with inferior patient-reported outcome measures following cervical disc replacement.

PURPOSE: This study aims to assess the correlation between the patient-reported mental health and the self-reported outcome measures (PROMs) physical function, pain, and disability at different time points following disc replacement (CDR). METHODS: A single-surgeon registry was searched for patients who had undergone CDR, excluding those with indication for infection, cancer, or trauma. One hundred fifty-one patients were included. PROMs were collected preoperatively as well as 6 weeks, 3 months, 6 months, and 1 year postoperatively. Mental health measures evaluated included 12-Item Short Form (SF-12), Mental Component Score (MCS), and Patient Health Questionnaire-9 (PHQ-9) which were individually assessed via Pearson's correlation tests in relation to Patient-Reported Outcome Measurement Information System Physical Function (PROMIS-PF), SF-12 Physical Component Score (PCS), visual analog scale (VAS) neck and arm pain, and Neck Disability Index (NDI). RESULTS: SF-12 MCS positively correlated with PROMIS-PF (range: r = 0.369-0.614) and SF-12 PCS (range: r = 0.208-0.585) with significance found at two or more time points for each (p ≤ 0.009, all). SF-12 MCS negatively correlated with VAS neck (range: r = - 0.259 to - 0.464), VAS arm (range: r = - 0.281 to - 0.567), and NDI (range: r = - 0.474 to - 831) with significance found at three or more time points (p ≤ 0.028, all). PHQ-9 significantly negatively correlated with PROMIS-PF (range: r = - 0.457 to - 0.732) and SF-12 PCS (range: r = - 0.332 to - 0.629) at all time points (p ≤ 0.013, all). PHQ-9 positively correlated with VAS neck (range: r = 0.351-0.711), VAS arm (range: r = 0.239-0.572), and NDI (range: r = 0.602-0.837) at four or more periods (p ≤ 0.032, all). CONCLUSION: Patients undergoing CDR who reported lower mental health scores via either SF-12 MCS or PHQ-9 were associated with increased perception of pain and disability. Disability level correlated with mental health at all time periods. Patients with optimized mental health may report higher outcome scores following CDR.

Postoperative clinical outcomes in patients undergoing MIS-TLIF versus LLIF for adjacent segment disease.

PURPOSE: Few studies examine the clinical outcomes in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) versus lateral lumbar interbody fusion (LLIF) for adjacent segment disease (ASD). We aim to compare the postoperative clinical trajectory through patient-reported outcome measures (PROMs) and minimum clinically important difference (MCID) in patients undergoing MIS-TLIF versus LLIF for ASD. METHODS: Patients were stratified into two cohorts based on surgical technique for ASD: MIS-TLIF versus LLIF. PROMs of 12-Item Short Form Physical Component Score (SF-12 PCS), visual analog scale (VAS) back, VAS leg, and Oswestry Disability Index (ODI) were collected at preoperative and postoperative 6-week/12-week/6-month/1-year time points. MCID attainment was calculated through comparison to established thresholds. Cohorts were compared through nonparametric inferential statistics. RESULTS: Fifty-four patients were identified, with 22 patients undergoing MIS-TLIF after propensity score matching. Patients undergoing MIS-TLIF for ASD demonstrated significant postoperative improvement up to 1-year VAS back, up to 1-year VAS leg, and 6-month through 1-year ODI (p ≤ 0.035, all). Patients undergoing LLIF demonstrated significant postoperative improvement in 6-month SF-12 PCS, 6-month through 1-year VAS back, 12-week through 6-month VAS leg, and 6-month to 1-year ODI (p ≤ 0.035, all). No significant differences were calculated between surgical techniques for PROMs or MCID achievement rates. CONCLUSION: Patients undergoing either MIS-TLIF or LLIF for adjacent segment disease demonstrated significant postoperative improvement in pain and disability outcomes. Additionally, patients undergoing LLIF reported significant improvement in physical function. Both MIS-TLIF and LLIF are effective for the treatment of adjacent segment disease.

Impact of preoperative symptom duration in patients undergoing lateral lumbar interbody fusion.

BACKGROUND: Few studies have examined the influence of preoperative symptom duration on clinical outcomes in patients undergoing lateral lumbar interbody fusion (LLIF) for degenerative conditions. METHODS: Patients undergoing LLIF presenting with radiculopathy and/or neurogenic claudication were separated into two groups: preoperative symptom duration < 1-year (shorter duration) versus duration ≥ 1-year (longer duration). Patients undergoing surgery for trauma/malignancy/infection were excluded. Patient-reported outcome measures (PROMs) of Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF), 12-Item Short Form Physical/Mental Component Score (SF-12 PCS/MCS), Patient Health Questionnaire-9 (PHQ-9), visual analog scale (VAS) back/leg, and Oswestry Disability Index (ODI) were collected at preoperative and postoperative time points. RESULTS: Eighty-two total patients, with 34 shorter-duration patients, were identified after propensity score matching for demographics. Longer-duration patients had higher estimated blood loss. All patients reported significant improvement in physical function, mental function, pain, and disability in at least one postoperative time point, except for SF-12 MCS in the shorter duration cohort. The longer duration cohort had higher MCID achievement in 12-week VAS back. CONCLUSION: Patients undergoing LLIF demonstrated significant postoperative improvement in physical function, mental function, pain, and disability outcomes independent of preoperative symptom duration. Both cohorts, when compared by preoperative symptom duration, demonstrated similar postoperative PROM scores. Patients with longer preoperative symptom duration had higher 12-week leg pain MCID achievement. These findings suggest that delayed time to surgery may not lead to inferior clinical outcomes in patients undergoing LLIF for degenerative conditions.

Time to achievement of minimum clinically important difference after lumbar decompression.

OBJECTIVE: The objective of this study is to examine factors associated with delayed time to achieve minimum clinically important difference (MCID) in patients undergoing lumbar decompression (LD) for the Patient-Reported Outcomes (PROs) of Oswestry Disability Index (ODI), Visual Analog Scale (VAS) back, and VAS leg pain. METHODS: Patients undergoing LD with preoperative and postoperative ODI, VAS back, and VAS leg scores were retrospectively reviewed from April 2016 to January 2021. MCID values from previously established studies were utilized to determine MCID achievement. Kaplan-Meier survival analysis determined the time to achieve MCID. Hazard ratios from multivariable Cox regression were utilized to determine the preoperative factors predictive of MCID achievement. RESULTS: Three-hundred and forty-three patients were identified undergoing LD. Overall MCID achievement rates were 67.4% for ODI, 67.1% for VAS back, and 65.0% for VAS leg. The mean time in weeks for MCID achievement was 22.52 ± 30.48 for ODI, 18.90 ± 27.43 for VAS back, and 20.96 ± 29.81 for VAS leg. Multivariable Cox regression revealed active smoker status, preoperative Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), ODI, VAS Back, and VAS Leg (HR 1.03-2.14) as predictors of early MCID achievement, whereas an American Society of Anesthesiologist (ASA) classification of 2, Black ethnicity, workers' compensation, private insurance, and diagnosis of foraminal stenosis were predictors of late MCID achievement (HR 0.34-0.58). CONCLUSION: Most patients undergoing LD achieved MCID within 6 months of surgery. Significant factors for early MCID achievement were active smoking status and baseline PROs. Significant factors for late MCID achievement were ASA = 2, Black ethnicity, type of insurance, and foraminal stenosis diagnosis. These factors may be considered by surgeons in setting patient expectations.

Effect of baseline veterans RAND-12 physical composite score on postoperative patient-reported outcome measures following lateral lumbar interbody fusion.

PURPOSE: To determine the prognostic value of preoperative Veterans RAND-12 (VR-12) Physical Composite Score (PCS) scores on postoperative clinical outcomes in patients undergoing lateral lumbar interbody fusion (LLIF). METHODS: LLIF patients were separated into 2 cohorts based on preoperative VR-12 PCS scores: VR-12 PCS < 30 (lesser physical function) and VR-12 PCS ≥ 30 (greater physical function). Patient-reported outcome measures (PROMs) of VR-12 PCS, VR-12 Mental Composite Score (MCS), Short Form-12 (SF-12) PCS, SF-12 MCS, Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), Patient Health Questionnaire-9 (PHQ-9), Visual Analog Scale (VAS) Back Pain (VAS-BP), VAS Leg Pain (VAS-LP), and Oswestry Disability Index (ODI) were collected at preoperative and up to 2-year postoperative time points. Mean postoperative follow-up time was 16.69 ± 8.53 months. Minimum clinically important difference (MCID) achievement was determined by comparing ∆PROM to previously established thresholds. RESULTS: Seventy-eight patients were included, with 38 patients with lesser preoperative physical function scores. Patients with lesser physical function reported significantly inferior preoperative PROM scores in all domains, except for SF-12 MCS and VAS-LP. At the 6-week postoperative time point, patients with lesser physical function reported significantly inferior VR-12 PCS, VR-12 MCS, SF-12 PCS, PROMIS-PF, and PHQ-9. At the final postoperative time point, patients with lesser physical function reported significantly inferior VR-12 PCS, VR-12 MCS, PROMIS-PF, PHQ-9, and ODI. Magnitude of 6-week postoperative improvement was significantly higher in the lesser physical function cohort for VR-12 PCS. CONCLUSION: Patients undergoing LLIF with worse baseline VR-12 PCS scores reported inferior postoperative physical function, mental health, and disability outcomes. At the final postoperative follow-up, magnitude of postoperative improvement and MCID achievement did not significantly differ. Baseline VR-12 PCS scores may indicate inferior postoperative clinical outcomes in physical function, mental health, and disability in patients undergoing LLIF; however, baseline VR-12 PCS does not limit the magnitude of postoperative improvement.

Preoperative predictors of prolonged hospitalization in patients undergoing lateral lumbar interbody fusion.

PURPOSE: We aim to examine the preoperative factors associated with increased postoperative length of stay in patients undergoing LLIF in the hospital setting. METHODS: Patient demographics, perioperative characteristics, and patient-reported outcome measures (PROMs) were collected from a single-surgeon database. Patients undergoing LLIF in the hospital setting were separated into postoperative LOS <48 h (H) and LOS ≥ 48H. Univariate analysis for preoperative characteristics was utilized to determine covariates for multivariable logistic regression. Multivariable logistic regression was then utilized to determine significant predictors of extended postoperative length of stay. Secondary univariate analysis of inpatient complications, operative, and postoperative characteristics were calculated to determine postoperative factors associated with prolonged hospitalization. RESULTS: Two-hundred and forty patients were identified with 115 patients' LOS ≥ 48H. Univariate analysis identified age/Charlson Comorbidity Index (CCI) score/gender/insurance type/number of contiguous fused levels/preoperative PROMs of Visual Analog Scale (VAS) back/VAS leg/Patient-Reported Outcomes Measurement Information System (PROMIS-PF)/Oswestry Disability Index (ODI)/degenerative spondylolisthesis diagnoses/foraminal stenosis/central stenosis for multivariable logistic regression. Multivariable logistic regression calculated significant positive predictors of LOS ≥ 48H to be age/3-level fusion/preoperative ODI scores. Negative predictors of LOS ≥ 48H were the diagnosis of foraminal stenosis/preoperative PROMIS-PF/male gender. The secondary analysis determined that patients with longer operative time/estimated blood loss/transfusion/postoperative day 0 and 1 pain and narcotic consumption/complications of altered mental status/postoperative anemia/fever/ileus/urinary retention were associated with prolonged hospitalization. CONCLUSION: Older patients undergoing LLIF with greater preoperative disability and 3-level fusion were more likely to require prolonged hospitalization. Male patients with higher preoperative physical function and who were diagnosed with foraminal stenosis were less likely to require prolonged hospitalization.

Impact of body mass index on PROMIS outcomes following lumbar decompression.

BACKGROUND: No studies have examined the impact of body mass index (BMI) on newer Patient-Reported Outcomes Measurement Information System (PROMIS) outcomes in patients undergoing lumbar decompression (LD). METHODS: Patients undergoing LD with preoperative PROMIS measures were stratified into four cohorts: normal (18.5 ≤ BMI < 25 kg/m2), overweight (25 ≤ BMI < 30 kg/m2), obese I (30 ≤ BMI < 35 kg/m2), and obese II-III (BMI ≥ 35 kg/m2). Demographics, perioperative characteristics, and patient-reported outcomes (PROs) were obtained. PROs of PROMIS Physical Function (PROMIS-PF), PROMIS Anxiety (PROMIS-A), PROMIS Pain Interference (PROMIS-PI), PROMIS Sleep Disturbance (PROMIS-SD), Patient Health Questionnaire-9 (PHQ-9), Visual Analog Scale (VAS) Back Pain (VAS-BP), VAS Leg Pain (VAS-LP), and Oswestry Disability Index (ODI) were collected at preoperative and up to 2-year postoperative time points. Minimum clinically important difference (MCID) achievement was determined through comparison of previously established values. Comparison between cohorts were determined through inferential statistics. RESULTS: A total of 473 patients were identified, with stratification of 125 patients in the normal cohort, 161 in the overweight cohort, 101 in the obese I cohort, and 87 in the obese II-III cohort. Mean postoperative follow-up time was 13.51 ± 8.72 months. Higher BMI patients had higher operative times, longer postoperative length of stay, and greater narcotic consumption (p ≤ 0.001, all). Patients with higher BMI (obese I, obese II-III) reported inferior preoperative PROMIS-PF, VAS-BP, and ODI scores (p ≤ 0.003, all). Postoperatively, obese I-III cohorts demonstrated inferior PROMIS-PF, PHQ-9, VAS-BP, and ODI scores at final follow-up (p ≤ 0.016, all). However, patients demonstrated similar postoperative changes and MCID achievement regardless of preoperative BMI. CONCLUSION: Patients undergoing lumbar decompression demonstrated similar postoperative improvement in physical function, anxiety, pain interference, sleep disturbance, mental health, pain, and disability outcomes independent of preoperative BMI. However, obese patients reported worse physical function, mental health, back pain, and disability outcomes at final postoperative follow-up. Patients with greater BMI undergoing lumbar decompression demonstrate inferior postoperative clinical outcomes.

Depressed patients with greater symptom duration before MIS-TLIF do not report inferior outcomes.

PURPOSE: Patients with preoperative depressive symptoms may demonstrate inferior patient-reported outcomes (PROs). The effect of preoperative symptom duration (SD) on PROs in this population has not been well-studied. We aim to assess the influence of preoperative SD on PROs in patients with low mental health scores prior to minimally invasive transforaminal interbody fusion (MIS-TLIF). METHODS: Patients who had undergone elective, primary MIS-TLIF with preoperative SF-12 MCS score below 45.6, a previously established threshold for depression, were selected. Patients were divided into matched lesser duration (LD; SD<365 days) and greater duration (GD; SD≥365 days) cohorts. PROs were collected preoperatively and at 6-week/12-week/6-month/1-year postoperative periods. PROs included PROMIS-PF/ODI/VAS back/VAS leg/SF-12 MCS. PROs were compared within and between groups. Rates of achievement of minimal clinically important difference (MCID) were compared between groups. RESULTS: One hundred twenty-two patients were included after matching cohorts. Patients in the LD cohort demonstrated improvement in PROMIS-PF at 12-weeks/6-month/1-year, and ODI/VAS back/VAS leg/SF-12 MCS at all postoperative periods (p≤0.024, all). Patients in the GD cohort demonstrated improvement in PROMIS-PF at 12-weeks/6-month/1-year, and ODI/VAS back/VAS leg/SF-12 MCS at all postoperative periods (p≤0.013, all). There were no differences in PROs or MCID achievement between cohorts at any period. CONCLUSION: Patients with preoperative depressive symptoms undergoing MIS-TLIF, regardless of duration of preoperative symptoms, demonstrated improvements in physical function, disability, pain, and mental health domains. Patients with greater duration of preoperative symptoms did not report inferior outcomes at any period. Rates of clinically important improvements in all domains were favorable and similar between cohorts.

Assessment of Photoreleasable Linkers and Light-Capturing Antennas on a Photoresponsive Cobalamin Scaffold.

Cobalamin has shown promise as a light-sensitive drug delivery platform owing to its ease of modification and the high quantum yields for drug photorelease. However, studies to date on the general photochemistry of alkyl cobalamins have primarily focused on methyl and adenosyl-substituted derivatives, the natural cofactors present in various enzymatic species. We describe the synthesis and photolytic behavior of cobalamin conjugates comprised of different combinations of fluorophores and ß-axial ligands. In general, cobalamin conjugates containing ß-axial alkyl substituents undergo efficient photolysis under aqueous conditions, with quantum yields up to >40%. However, substituents that are large and hydrophobic, or unable to readily support the presumed radical intermediate, suffer less efficient photolysis (<15%) than smaller, water-soluble, analogs. By contrast, quantum yields improve by 2-fold in DMF for cobalamins containing large hydrophobic ß-axial substituents. This suggests that drug release from carriers comprised of membranous compartments, such as liposomes, may be significantly more efficient than the corresponding photorelease in an aqueous environment. Finally, we explored the impact of fluorophores on the photolysis of alkyl cobalamins under tissue-mimetic conditions. Cobalamins substituted with efficient photon-capturing fluorophores display up to 4-fold enhancements in photolysis relative to unsubstituted derivatives. In summary, we have shown that the photosensitivity of alkyl cobalamin conjugates can be tuned by altering the Co-appended alkyl moiety, modulating the polarity of the environment (solvent), and installing photon-capturing fluorophores onto the cobalamin framework.

Management of lymphocele following anterior lumbar interbody fusion, case report and review of literature.

While anterior lumbar interbody fusion (ALIF) is known as an established and safe procedure for treatment of degenerative disc disease, albeit rare, the development of postoperative intra-abdominal or retroperitoneal collection of lymph warrants timely diagnosis and management. This study presents the case of a 62-year-old male who underwent L4-L5 and L5-S1 ALIF and developed a persistent left-sided fluid collection, resulting in a symptomatic retroperitoneal lymphocele confirmed by computed tomography (CT). After percutaneous drainage by interventional radiology (IR), output remained high at 1 liter (L) per day, necessitating sclerotherapy with doxycycline and ethanol. In the absence of improvement, a lymphangiogram demonstrating a persistent lymph leak and glue embolization was performed. Due to refractory symptoms, retroperitoneal exploration with methylene blue dye was utilized for lymphatic mapping, and a lymphatic capillary leak in proximity to the left iliac artery was identified and successfully ligated with resolution of symptoms. With suspected fluid collections following ALIF, confirmation with CT or ultrasound (US) imaging followed by percutaneous drainage and testing of fluid is necessary. In mild cases, drainage alone or nonsurgical chemical sclerotherapy may suffice. In symptomatic refractory cases, localization of the site with lymphangiogram or US-guided injection of methylene blue dye allows for easier identification and definitive management with either transabdominal laparoscopic fenestration or retroperitoneal surgical exploration and ligation.

The Surgical Learning Curve for Cervical Disk Replacement.

STUDY DESIGN: Retrospective study. OBJECTIVE: To characterize an experienced single surgeon learning curve for cervical disk replacement (CDR). SUMMARY OF BACKGROUND DATA: A single surgeon learning curve has not been established for CDR. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Impact of American Society of Anesthesiologists' Classification on Postoperative Satisfaction and Clinical Outcomes Following Lumbar Decompression: Cohort-Matched Analysis.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: The aim was to compare patient-reported outcomes (PROMs), minimum clinically important difference (MCID) achievement, and postoperative satisfaction following minimally invasive lumbar decompression in patients stratified by American Society of Anesthesiologists (ASA) classification. SUMMARY OF BACKGROUND DATA: Some guidelines recommend against performing elective procedures for patients with an ASA score of 3 or greater; however, long-term postoperative outcomes are not well described. METHODS: Primary, single-level, minimally invasive lumbar decompression procedures were identified. PROMs were administered at preoperative, 6-week, 12-week, 6-month, 1-year, 2-year timepoints and included Patient-Reported Outcomes Measurement Information System-Physical Function, visual analog scale (VAS) back/leg, Oswestry disability index (ODI), and 12-item short form physical component score. Satisfaction scores were collected postoperatively for VAS back/leg, ODI, and individual ODI subcategories. Patients were grouped (ASA<3, ASA≥3), and propensity scores were matched to control for significant differences. Demographic and perioperative characteristics were compared using χ 2 and the Student's t test. Mean PROMs and postoperative satisfaction were compared at each time point by a 2-sample t test. Postoperative PROM improvement from the preoperative baseline within each cohort was calculated with a paired t test. MCID achievement was determined by comparing ΔPROMs to established thresholds and comparing between groups using simple logistic regression. RESULTS: One hundred and twenty-nine propensity-matched patients were included: 99 ASA<3 and 30 ASA≥3. No significant demographic differences were observed between groups. ASA≥3 patients experienced significantly increased length of stay and postoperative narcotic consumption on surgery day ( P <0.048, all). Mean PROMs and MCID achievement did not differ. The ASA<3 cohort significantly improved from the preoperative baseline for all PROMs at all postoperative time points. ASA<3 patients demonstrated higher levels of postoperative satisfaction at 6 weeks for VAS leg, VAS back, ODI, sleeping, lifting, walking, standing, sex, travel, and at 6 months for VAS back ( P <0.045, all). CONCLUSION: ASA≥3 patients may achieve similar long-term clinical outcomes to ASA<3 patients, though they may show poorer short-term satisfaction for disability, leg pain, and back pain, which could be related to differing preoperative expectations.

Does Preoperative Back Pain Impact Patient-reported Outcomes in Patients Undergoing Minimally Invasive Transforaminal Lumbar Interbody Fusion for Isthmic Spondylolisthesis?

STUDY DESIGN: Retrospective review. OBJECTIVE: To determine postoperative clinical outcomes in patients undergoing minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF) for isthmic spondylolisthesis (IS). BACKGROUND: Few studies have examined the postoperative clinical trajectory in patients undergoing MIS-TLIF specifically for IS. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Medicare procedural costs in ambulatory surgery centers versus hospital outpatient departments for spine surgeries.

OBJECTIVE: Multiple studies have demonstrated the safety of outpatient spine surgery, with reports of equivalent to improved patient outcomes compared with inpatient procedures. This has resulted in the increased use of outpatient surgery over time. However, there remains a paucity of literature evaluating the difference in costs between ambulatory surgery center (ASC)- and hospital outpatient department (HOPD)-based procedures for Medicare beneficiaries. METHODS: Publicly available data from Centers for Medicare & Medicaid Services were accessed via the Medicare Procedure Price Lookup tool. Current Procedural Terminology (CPT) codes were used to identify spine-specific procedures approved for the outpatient setting by CMS. Procedures were grouped into decompression (cervical, thoracic, and lumbar), fusion/instrumentation (cervical, lumbar, and sacroiliac), and kyphoplasty/vertebroplasty cohorts, as well as an overall cohort. Data regarding total costs, facility fees, surgeon reimbursement, Medicare payments, and patient copayments were extracted for each procedure. Descriptive statistics were used to calculate means and standard deviations. Differences between ASC- and HOPD-associated costs were analyzed using the Mann-Whitney U-test. RESULTS: Twenty-one individual CPT codes approved by Medicare for the ASC and/or HOPD setting were identified. Decompression procedures were associated with a significantly lower total cost ($4183 ± $411.07 vs $7583.67 ± $410.89, p < 0.001), facility fees ($2998 ± $0 vs $6397 ± $0, p < 0.001), Medicare payments ($3345.75 ± $328.80 vs $6064.75 ± $328.80, p < 0.001), and patient payments ($835.58 ± $82.13 vs $1515.58 ± $82.13, p < 0.001) in ASCs compared with HOPDs. Fusion/instrumentation procedures had significantly lower facility fees ($10,436.6 ± $2347.51 vs $14,161 ± $2147.07, p = 0.044) and Medicare payments ($9501.2 ± $1732.42 vs $13,757 ± $2037.58, p = 0.009) in ASCs, as well as a trend toward lower total costs ($11,876.8 ± $2165.22 vs $15,601.2 ± $2016.06, p = 0.076). Patient payments in the HOPD setting were significantly lower in the fusion/instrumentation cohort ($1843.6 ± $73.42 vs $2374.4 ± $433.48, p = 0.009). In the kyphoplasty/vertebroplasty cohort, there was no statistically significant difference between ASCs and HOPDs, despite lower overall costs in the ASC for all variables. Surgeon fees were the same regardless of setting for all procedures (p > 0.99). When combining decompression, fusion/instrumentation, and kyphoplasty/vertebroplasty CPT codes into a single cohort, ASC setting was associated with significant cost savings in total cost, facility fees, Medicare payments, and patient payments. CONCLUSIONS: In general, performing spine surgeries in ASCs is associated with cost savings compared with HOPDs. This was demonstrated for decompression and fusion/instrumentation, and kyphoplasty/vertebroplasty Medicare-approved outpatient procedures.

The influence of preoperative Veterans RAND-12 physical composite score in patients undergoing anterior lumbar interbody fusion [Retrospective Review].

No study has evaluated the preoperative impact of Veterans RAND-12 Physical Composite Score (VR-12 PCS) on anterior lumbar interbody fusion (ALIF) patients. This study examines its influence on physical function, mental health, pain, and disability outcomes. Two cohorts of ALIF patients with preoperative VR-12 PCS scores were formed using a single-surgeon registry: VR-12 PCS < 30 and VR-12 PCS ≥ 30. Demographics, perioperative characteristics, and patient-reported outcome measures (PROMs) were collected. PROMs of VR-12 PCS/Mental Composite Score (MCS), Short Form-12 (SF-12) PCS/MCS, Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF), Patient Health Questionnaire-9 (PHQ-9), Visual Analog Scale-Back/Leg Pain (VAS-BP/LP), and Oswestry Disability Index (ODI) were collected pre/postoperatively up to 2-years. Demographics, perioperative characteristics, and preoperative PROMs were compared. Intercohort postoperative 6-week/final PROMs and improvements were compared. Of 80 patients, there were 41 in the VR-12 PCS < 30 cohort. Besides VR-12 PCS, VR-12 PCS < 30 patients reported inferior preoperative VR-12 MCS/SF-12 PCS/PROMIS-PF/PHQ-9/ODI scores (p ≤ 0.003, all). At 6-weeks postoperatively, VR-12 PCS < 30 reported inferior VR-12 PCS/SF-12 PCS/PROMIS-PF/PHQ-9 (p ≤ 0.030, all). There was greater improvement up to 6-weeks postoperatively in VR-12 PCS < 30 for VR-12 PCS/MCS and SF-12 PCS (p ≤ 0.020, all). VR-12 PCS < 30 reported superior improvement by final follow-up in VR-12 PCS/SF-12 PCS/PHQ-9 (p ≤ 0.006, all). MCID achievement rates were higher in VR-12 PCS < 30 for PHQ-9 and ODI (p ≤ 0.013, both). VR-12 PCS < 30 patients reported inferior postoperative physical function, mental health, and disability, yet superior magnitude of improvement in physical function and mental health. Rates of clinically meaningful improvement for VR-12 PCS < 30 were greater in mental health and disability.

Effect of Baseline Veterans RAND-12 Mental Composite Score on Postoperative Patient-Reported Outcome Measures for Cervical Disk Replacement.

STUDY DESIGN: Retrospective review. OBJECTIVE: 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. BACKGROUND: Few studies in spine surgery have evaluated the impact of preoperative VR-12 MCS on postoperative outcomes in patients undergoing CDR. METHODS: 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. RESULTS: 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. CONCLUSION: 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.