Mechanical complications and patient-reported outcome measures associated with high pelvic incidence and persistent pelvic retroversion: the Roussouly "false type 2" profile.

OBJECTIVE: The objective of this paper was to report mechanical complications and patient-reported outcome measures (PROMs) for adult spinal deformity (ASD) patients with a Roussouly "false type 2" (FT2) profile. METHODS: ASD patients treated from 2004 to 2014 at a single center were identified. Inclusion criteria were pelvic incidence ≥ 60° and a minimum 2-year follow-up. FT2 was defined as a high postoperative pelvic tilt (PT), as defined by the Global Alignment and Proportion target, and thoracic kyphosis < 30°. Mechanical complications, defined as proximal junctional kyphosis (PJK) and/or instrumentation failure, were determined and compared. Scoliosis Research Society-22r (SRS-22r) scores were compared between groups. RESULTS: Ninety-five patients (normal PT [NPT] group 49, FT2 group 46) who met the inclusion criteria were identified and studied. Most surgeries were revisions (NPT group 30 [61%], FT2 group 30 [65%]), and most were performed via a posterior-only approach (86%) (mean ± SD 9.6 ± 5 levels). Proximal junctional angles increased after surgery in both groups, without differences between groups. Neither rates of radiographic PJK (p = 0.10), revision for PJK (p = 0.45), nor revision for pseudarthrosis (p = 0.66) were different between groups. There were no differences between groups for SRS-22r domain scores or subscores. CONCLUSIONS: In this single-center experience, patients with high pelvic incidence fixed with persistent lumbopelvic parameter mismatch and engaged compensatory mechanisms (Roussouly FT2) had mechanical complications and PROMs not different from those with normalized alignment parameters. Compensatory PT may be acceptable in some cases of ASD surgery.

Validation of Adult Spinal Deformity Surgical Outcome Prediction Tools in Adult Symptomatic Lumbar Scoliosis.

STUDY DESIGN: A post hoc analysis. OBJECTIVE: Advances in machine learning (ML) have led to tools offering individualized outcome predictions for adult spinal deformity (ASD). Our objective is to examine the properties of these ASD models in a cohort of adult symptomatic lumbar scoliosis (ASLS) patients. SUMMARY OF BACKGROUND DATA: ML algorithms produce patient-specific probabilities of outcomes, including major complication (MC), reoperation (RO), and readmission (RA) in ASD. External validation of these models is needed. METHODS: Thirty-nine predictive factors (12 demographic, 9 radiographic, 4 health-related quality of life, 14 surgical) were retrieved and entered into web-based prediction models for MC, unplanned RO, and hospital RA. Calculated probabilities were compared with actual event rates. Discrimination and calibration were analyzed using receiver operative characteristic area under the curve (where 0.5=chance, 1=perfect) and calibration curves (Brier scores, where 0.25=chance, 0=perfect). Ninety-five percent confidence intervals are reported. RESULTS: A total of 169 of 187 (90%) surgical patients completed 2-year follow up. The observed rate of MCs was 41.4% with model predictions ranging from 13% to 68% (mean: 38.7%). RO was 20.7% with model predictions ranging from 9% to 54% (mean: 30.1%). Hospital RA was 17.2% with model predictions ranging from 13% to 50% (mean: 28.5%). Model classification for all three outcome measures was better than chance for all [area under the curve=MC 0.6 (0.5-0.7), RA 0.6 (0.5-0.7), RO 0.6 (0.5-0.7)]. Calibration was better than chance for all, though best for RA and RO (Brier Score=MC 0.22, RA 0.16, RO 0.17). CONCLUSIONS: ASD prediction models for MC, RA, and RO performed better than chance in a cohort of adult lumbar scoliosis patients, though the homogeneity of ASLS affected calibration and accuracy. Optimization of models require samples with the breadth of outcomes (0%-100%), supporting the need for continued data collection as personalized prediction models may improve decision-making for the patient and surgeon alike.

Alvimopan for the reduction of postoperative ileus after long posterior spinal fusion: placebo-controlled double-blind randomized trial.

OBJECTIVE: The aim of this study was to evaluate the efficacy of alvimopan administration after posterior spinal fusion (PSF) in adult spine surgery patients who are taking opioid agents. METHODS: In this placebo-controlled, double-blind randomized trial, PSF patients were randomized in blocks to placebo or study drug. Primary and secondary outcome measures were return to normal bowel function, including time to passage of flatus and stool, time to tolerance of oral nutrition, and time to hospital discharge. Patients were included regardless of chronic opioid consumption status. RESULTS: Thirty-one patients provided consent for participation, and 26 patients (13 per group) completed the study. There were no differences between groups with respect to time to flatus, time to bowel movement, time to oral nutrition tolerance, and time to discharge. Calculated effect sizes favored placebo for all interventions. CONCLUSIONS: Alvimopan did not hasten return to bowel function for any primary or secondary outcome measures when compared with placebo for patients undergoing PSF. There were no adverse events related to alvimopan, including for patients with chronic opioid consumption. While underpowered to determine a statistical difference, it is unlikely that a clinically relevant effect exists.

Patient-reported outcome measure clustering after surgery for adult symptomatic lumbar scoliosis.

OBJECTIVE: Adult symptomatic lumbar scoliosis (ASLS) is a widespread and debilitating subset of adult spinal deformity. Although many patients benefit from operative treatment, surgery entails substantial cost and risk for adverse events. Patient-reported outcome measures (PROMs) are patient-centered tools used to evaluate the appropriateness of surgery and to assist in the shared decision-making process. Framing realistic patient expectations should include the possible functional limitation to improvement inherent in surgical intervention, such as multilevel fusion to the sacrum. The authors' objective was to predict postoperative ASLS PROMs by using clustering analysis, generalized longitudinal regression models, percentile analysis, and clinical improvement analysis of preoperative health-related quality-of-life scores for use in surgical counseling. METHODS: Operative results from the combined ASLS cohorts were examined. PROM score clustering after surgery investigated limits of surgical improvement. Patients were categorized by baseline disability (mild, moderate, moderate to severe, or severe) according to preoperative Scoliosis Research Society (SRS)-22 and Oswestry Disability Index (ODI) scores. Responder analysis for patients achieving improvement meeting the minimum clinically important difference (MCID) and substantial clinical benefit (SCB) standards was performed using both fixed-threshold and patient-specific values (MCID = 30% of remaining scale, SCB = 50%). Best (top 5%), worst (bottom 5%), and median scores were calculated across disability categories. RESULTS: A total of 171/187 (91%) of patients with ASLS achieved 2-year follow-up. Patients rarely achieved a PROM ceiling for any measure, with 33%-43% of individuals clustering near 4.0 for SRS domains. Patients with severe baseline disability (< 2.0) SRS-pain and SRS-function scores were often left with moderate to severe disability (2.0-2.9), unlike patients with higher (≥ 3.0) initial PROM values. Patients with mild disability according to baseline SRS-function score were unlikely to improve. Crippling baseline ODI disability (> 60) commonly left patients with moderate disability (median ODI = 32). As baseline ODI disability increased, patients were more likely to achieve MCID and SCB (p < 0.001). Compared to fixed threshold values for MCID and SCB, patient-specific values were more sensitive to change for patients with minimal ODI baseline disability (p = 0.008) and less sensitive to change for patients with moderate to severe SRS subscore disability (p = 0.01). CONCLUSIONS: These findings suggest that ASLS surgeries have a limit to possible improvement, probably due to both baseline disability and the effects of surgery. The most disabled patients often had moderate to severe disability (SRS < 3, ODI > 30) at 2 years, emphasizing the importance of patient counseling and expectation management.