Improved Surgical Correction Relative to Patient-Specific Ideal Spinopelvic Alignment Reduces Pelvic Nonresponse for Severely Malaligned Adult Spinal Deformity Patients.

BACKGROUND: Persistent pelvic compensation following adult spinal deformity (ASD) corrective surgery may impair quality of life and result in persistent pathologic lower extremity compensation. Ideal age-specific alignment targets have been proposed to improve surgical outcomes, though it is unclear whether reaching these ideal targets reduces rates of pelvic nonresponse following surgery. Our aim was to assess the relationship between pelvic nonresponse, age-specific alignment, and lower-limb compensation following surgery for ASD. METHODS: Single-center retrospective cohort study. ASD patients were grouped: those who did not improve in Scoliosis Research Society-Schwab pelvic tilt (PT) modifier (pelvic nonresponders [PNR]), and those who improved (pelvic responders [PR]). Groups were propensity score matched for preoperative PT and assessed for differences in spinal and lower extremity alignment. Rates of pelvic nonresponse were compared across patient groups who were undercorrected, overcorrected, or matched age-specific postoperative alignment targets. RESULTS: A total of 146 surgical ASD patients, 47.9% of whom showed pelvic nonresponse following surgery, were included. After propensity score matching, PNR (N = 29) and PR (N = 29) patients did not differ in demographics, preoperative alignment, or levels fused; however, PNR patients have less preoperative knee flexion (9° vs 14°, P = 0.043). PNR patients had inferior postoperative pelvic incidence and lumbar lordosis (PI-LL) alignment (17° vs 3°) and greater pelvic shift (53 vs 31 mm). PNR and PR patients did not differ in rates of reaching ideal age-specific postoperative alignment for sagittal vertical axis (SVA) or PI-LL, though patients who matched ideal PT had lower rates of PNR (25.0% vs 75.0%). For patients with moderate and severe preoperative SVA, more aggressive correction relative to either ideal postoperative PT or PI-LL was associated with significantly lower rates of pelvic nonresponse (all P < 0.05). CONCLUSIONS: For patients with moderate to severe baseline truncal inclination, more aggressive surgical correction relative to ideal age-specific PI-LL was associated with lower rates of pelvic nonresponse. Postoperative alignment targets may need to be adjusted to optimize alignment outcomes for patients with substantial preoperative sagittal deformity. CLINICAL RELEVANCE: These findings increase our understanding of the poor outcomes that occur despite ideal realignment. Surgical correction of severe global sagittal deformity should be prioritized to mitigate these occurrences.

The Patient-Reported Outcome Measurement Information System (PROMIS) Better Reflects the Impact of Length of Stay and the Occurrence of Complications Within 90 Days Than Legacy Outcome Measures for Lumbar Degenerative Surgery.

BACKGROUND: The Patient-Reported Outcome Measurement Information System (PROMIS) and legacy outcome measures like the Oswestry Disability Index (ODI) have not been compared for their sensitivity in reflecting the impact of perioperative complications and length of stay (LOS) in a surgical thoracolumbar population. The purpose of this study is to assess the strength of PROMIS and ODI scores as they correlate with LOS and complication outcomes of surgical thoracolumbar patients. METHODS: Retrospective cohort study. Included: patients ≥18 years undergoing thoracolumbar surgery with available preoperative and 3-month postoperative ODI and PROMIS scores. Pearson correlation assessed the linear relationships between LOS, complications, and scores for PROMIS (physical function, pain intensity, pain interference) and ODI. Linear regression predicted the relationship between complication incidence and scores for ODI and PROMIS. RESULTS: Included: 182 patients undergoing thoracolumbar surgery. Common diagnoses were stenosis (62.1%), radiculopathy (48.9%), and herniated disc (47.8%). Overall, 58.3% of patients underwent fusion, and 50.0% underwent laminectomy. Patients showed preoperative to postoperative improvement in ODI (50.2 to 39.0), PROMIS physical function (10.9 to 21.4), pain intensity (92.4 to 78.3), and pain interference (58.4 to 49.8, all P < .001). Mean LOS was 2.7 ± 2.8 days; overall complication rate was 16.5%. Complications were most commonly cardiac, neurologic, or urinary (all 2.2%). Whereas preoperative to postoperative changes in ODI did not correlate with LOS, changes in PROMIS pain intensity (r = 0.167, P = .024) and physical function (r = -0.169, P = .023) did. Complications did not correlate with changes in ODI or PROMIS score; however, postoperative scores for physical function (r = -0.205, P = .005) and pain interference (r = 0.182, P = .014) both showed stronger correlations with complication occurrence than ODI (r = 0.143, P = .055). Regression analysis showed postoperative physical function (R 2 = 0.037, P = .005) and pain interference (R 2 = 0.028, P = .014) could predict complications; ODI could not. CONCLUSIONS: PROMIS domains of physical function and pain interference better reflected perioperative complications and LOS than the ODI. These results suggest PROMIS may offer more utility as an outcomes assessment instrument. LEVEL OF EVIDENCE: 3.

Ossification of the Posterior Longitudinal Ligament in Cervical Spine Cases Trends in Surgical Treatments and Outcomes in the US from 2005 to 2013.

BACKGROUND: Ossification of the posterior longitudinal ligament (OPLL) is characterized by ectopic bone formation within the ligament and can elicit cervical spinal canal stenosis. Surgical treatment for OPLL is debated in the literature. This study examined nationwide data to estimate the prevalence of cervical OPLL (C-OPLL) and investigated trends in surgical treatment and outcomes. METHODS: A retrospective cross-sectional study was conducted of the National Inpatient Sample (NIS) database for patients with a diagnosis code for C-OPLL (ICD-9-CM 723.7) from 2005 to 2013. NIS supplied hospital- and yearadjusted weights allowed for accurate assessment of prevalence. Descriptive statistics assessed patient demographics, comorbidities, surgical factors, and complications. Trends were analyzed using chi-squared, ANOVA, and independent sample t-tests. RESULTS: A total of 4,601 C-OPLL discharges were identified (56.7 years, 43% female). The prevalence of C-OPLL has increased from 0.7/100,000 in 2005 to 2.1/100,000 in 2013. Among hospitalized C-OPLL patients, 89.1% underwent surgery, with 62.1% undergoing an anterior-only (A) approach, 21.5% posterior-only (P), and 16.4% combined (AP). Rates of anterior- and decompression-only surgeries have declined since 2005, from 67.5% to 44.4% and 21.6% to 14.8%, respectively (p < 0.001 for both). Corpectomy rates have dramatically increased, from 3.6% to 27.2% (p < 0.001). Overall complication rates have increased 2.5% since 2005 (p < 0.001) with higher rates of dysphagia (0.7%) and dural tears (5.6%) associated with A-only surgeries (p < 0.001 for both). The overall mortality rate was 0.8%, with P surgery associated with the highest rate, 1.6% (p = 0.002). CONCLUSIONS: The rate of hospitalization for C-OPLL has increased over the last decade as have morbidity rates for C-OPLL discharges. Anterior-only surgeries were associated with higher complication rates. Surgical rates have remained constantsince 2005, butrates of anterior-only and decompression-only procedures have decreased in favor of posterior-only and combined-approach surgeries.

Prevalence of Sagittal Spinal Deformity Among Patients Undergoing Total Hip Arthroplasty.

BACKGROUND: The important relationship between sagittal spinal alignment and total hip arthroplasty (THA) is becoming well recognized. Prior research has shown a significant relationship between sagittal spinal deformity (SSD) and THA instability. This study aims at determining the prevalence of SSD among preoperative THA patients. METHODS: A multicenter database of preoperative THA patients was analyzed. Radiographic parameters measured from standing radiographs included anterior pelvic plane tilt, spinopelvic tilt, and lumbar lordosis (LL); pelvic incidence (PI) was measured from computed tomography scans. Lumbar flatback was defined as PI-LL mismatch >10°, balanced as PI-LL of -10° to 10°, and hyperlordosis as PI-LL <-10°. RESULTS: A total of 1088 patients were analyzed (mean, 64 years; 48% female). And 59% (n = 644) of patients had balanced alignment, 16% (n = 174) had a PI-LL > 10°, and 4% (n = 46) had a PI-LL > 20° (severe flatback deformity). The prevalence of hyperlordosis was 25% (n = 270). Flatback patients tended to be older than balanced and hyperlordotic patients (69.5 vs 64.0 vs 60.8 years, P < .001). Spinopelvic tilt was more posterior in flatback compared to balanced and hyperlordotic patients (24.7° vs 15.4° vs 7.0°) as was anterior pelvic plane tilt (-7.1° vs -2.0° vs 2.5°) and PI (64.1° vs 56.8° vs 49.0°), all P < .001. CONCLUSION: Only 59% of patients undergoing THA have normally aligned lumbar spines. Flatback SSD was observed in 16% (4% with severe flatback deformity) and there was a 25% prevalence of hyperlordosis. Lumbar flatback was associated with increasing age, posterior pelvic tilt, and larger PI. The relatively high prevalence of spinal deformity in this population reinforces the importance of considering spinopelvic alignment in THA planning and risk stratification.

Factors influencing length of stay following cervical spine surgery: A comparison of myelopathy and radiculopathy patients.

In the current value-based healthcare climate where spine surgery is shifting to the ambulatory setting, factors influencing postop length of stay (LOS) are important to surgeons and hospital administrators. Pre-op patient factors including diagnosis of radiculopathy and myelopathy have yet to be investigated in this context. Operative pts ≥ 18Y with primary diagnoses of cervical myelopathy (M), radiculopathy (R), or myeloradiculopathy (MR) were included and propensity score matched by invasiveness score (Mirza et al.). Top-quartile LOS was defined as extended. M&R patients were compared using Chi2 & independent t-tests. Univariate tests assessed differences in preop patient and surgical data in M&R pts and extended/non-extended LOS. Stepwise regression analysis explored factors predictive of LOS. 718 operative pts (54.5 yrs, 41.1%F, 29.1 kg/m2, mean CCI 1.11) included (177 M, 383 R, and 158 MR). After PSM, 345 patients remained (115 in each diagnosis). 102 patients had E-LOS (Avg: 5.96 days), 41 M patients (mean 7.1 days), 28 R (5.9 days), and 33 MR (4.6 days). Regression showed predictors of E-LOS in R pts (R2 = 0.532, p = 0.043): TS-CL, combined and posterior approach, LIV, UIV, op time, Lactated Ringer's, postoperative complications. Predictors of E-LOS in M pts (R2 = 0.230, p < 0.001): age, CCI, combined and posterior approach, levels fused, UIV, EBL, neuro and any postop complications. Predictors of E-LOS in MR patients (R2 = 0.152, p < 0.001): age, kyphosis, combined approach, UIV, LIV, levels fused, EBL and op time. Independent of invasiveness, patients with a primary diagnosis of myelopathy, though older aged and higher comorbidity profile, had consistently longer overall postop LOS when compared to radiculopathy or myeloradiculopathy patients.