Feline distichiasis treated with cryoepilation: A retrospective study of 15 cats (27 eyes)

OBJECTIVE

To describe the clinical features of cats diagnosed with distichiasis and report on the outcomes following cryoepilation.

ANIMALS STUDIED

Fifteen cats (27 eyes).

PROCEDURES

Medical records of domestic cats with distichiasis that underwent a double freeze-thaw cycle with a -80°C cryoprobe applied to the palpebral conjunctiva, with hair then epilated were retrospectively studied. The patient signalment, distichiae locations, concurrent ocular diseases, recurrences, complications, and outcomes were recorded.

RESULTS

The mean (std dev) age at the time of diagnosis and treatment was 2.2 years (2.8 years). All (15/15) cats were of the domestic shorthair (DSH) breed. Concurrent ocular findings at the initial examination were observed in 17/27 (63%) eyes, with upper lateral eyelid hypoplasia the most prevalent, present in 9/27 (33.3%) eyes. Recurrence of distichiae occurred in 8/27 (29.6%) eyes. The clinical presentation in the instances of recurrence was judged as asymptomatic and not of a clinical concern in 3/27 (11.1%) eyes, with a second procedure deemed necessary to alleviate symptoms in 5/27 (18.5%) eyes. All eyes treated with a second procedure had no recurrence of distichiae or symptoms. Complications following cryoepilation occurred in 4/27 (14.8%) eyes, with two cats developing bilateral entropion post-procedure.

CONCLUSIONS

Treatment of distichiasis in cats utilizing cryoepilation was effective at alleviating symptoms, though some cats needed a second procedure. The development of post-procedural entropion was seen occasionally.

Complication Rates Following Adult Spinal Deformity Surgery: Evaluation of the Category of Complication and Chronology

OBJECTIVE

Provide benchmarks for the rates of complications by type and timing.

STUDY DESIGN

Prospective multicenter database.

BACKGROUND

Complication rates following adult spinal deformity (ASD) surgery have been previously reported. However, the interplay between timing and complication type warrants further analysis.

METHODS

The data for this study were sourced from a prospective, multicenter ASD database. Date and type of complication were collected and classified into three severity groups (minor, major, major leading to reoperation). Only complications occurring before the 2-year visit were retained for analysis.

RESULTS

Of the 1260 patients eligible for 2-year follow-up, 997 (79.1%) achieved 2-year follow-up. The overall complication rate was 67.4% (N=672). 247 patients (24.8%) experienced at least one complication on the day of surgery (including intra-operatively), 359 (36.0%) between post-op day 1 and 6 weeks post-op, 271 (27.2%) between 6 weeks and 1 one -year post-op, and finally 162 (16.3%) between 1 year and 2 years post-op. Using Kaplan-Meier survival analysis, the rate of remaining complication-free was estimated at different time points for different severities and types of complications. Stratification by type of complication demonstrated that most of the medical complications occurred within the first 60 days. Surgical complications presented over two distinct timeframes. Operative complications, incision-related complications, and infections occurred early (within 60 d), while implant-related and radiographic complications occurred at a constant rate over the 2-year follow-up period. Neurologic complications had the highest occurrence within the first 60 days but continued to increase up to the 2-year visit.

CONCLUSION

Only one-third of ASD patients remained complication-free by 2 years, and 2 out of 10 patients had a complication requiring a reoperation or revision. Estimation of timing and type of complication associated with surgical treatment may prove useful for more meaningful patient counseling and aid in assessing the cost-effectiveness of treatment.

Persistent Lower Extremity Compensation for Sagittal Imbalance After Surgical Correction of Complex Adult Spinal Deformity: A Radiographic Analysis of Early Impact

BACKGROUND AND OBJECTIVES

Achieving spinopelvic realignment during adult spinal deformity (ASD) surgery does not always produce ideal outcomes. Little is known whether compensation in lower extremities (LEs) plays a role in this disassociation. The objective is to analyze lower extremity compensation after complex ASD surgery, its effect on outcomes, and whether correction can alleviate these mechanisms.

METHODS

We included patients with complex ASD with 6-week data. LE parameters were as follows: sacrofemoral angle, knee flexion angle, and ankle flexion angle. Each parameter was ranked, and upper tertile was deemed compensation. Patients compensating and not compensating postoperatively were propensity score matched for body mass index, frailty, and T1 pelvic angle. Linear regression assessed correlation between LE parameters and baseline deformity, demographics, and surgical details. Multivariate analysis controlling for baseline deformity and history of total knee/hip arthroplasty evaluated outcomes.

RESULTS

Two hundred and ten patients (age: 61.3 ± 14.1 years, body mass index: 27.4 ± 5.8 kg/m2, Charlson Comorbidity Index: 1.1 ± 1.6, 72% female, 22% previous total joint arthroplasty, 24% osteoporosis, levels fused: 13.1 ± 3.8) were included. At baseline, 59% were compensating in LE: 32% at hips, 39% knees, and 36% ankles. After correction, 61% were compensating at least one joint. Patients undercorrected postoperatively were less likely to relieve LE compensation (odds ratio: 0.2, P = .037). Patients compensating in LE were more often undercorrected in age-adjusted pelvic tilt, pelvic incidence, lumbar lordosis, and T1 pelvic angle and disproportioned in Global Alignment and Proportion (P < .05). Patients matched in sagittal age-adjusted score at 6 weeks but compensating in LE were more likely to develop proximal junctional kyphosis (odds ratio: 4.1, P = .009) and proximal junctional failure (8% vs 0%, P = .035) than those sagittal age-adjusted score-matched and not compensating in LE.

CONCLUSION

Perioperative lower extremity compensation was a product of undercorrecting complex ASD. Even in age-adjusted realignment, compensation was associated with global undercorrection and junctional failure. Consideration of lower extremities during planning is vital to avoid adverse outcomes in perioperative course after complex ASD surgery.

Patient-specific Cervical Deformity Corrections With Consideration of Associated Risk: Establishment of Risk Benefit Thresholds for Invasiveness Based on Deformity and Frailty Severity

STUDY DESIGN/SETTING

This was a retrospective cohort study.

BACKGROUND

Little is known of the intersection between surgical invasiveness, cervical deformity (CD) severity, and frailty.

OBJECTIVE

The aim of this study was to investigate the outcomes of CD surgery by invasiveness, frailty status, and baseline magnitude of deformity.

METHODS

This study included CD patients with 1-year follow-up. Patients stratified in high deformity if severe in the following criteria: T1 slope minus cervical lordosis, McGregor's slope, C2-C7, C2-T3, and C2 slope. Frailty scores categorized patients into not frail and frail. Patients are categorized by frailty and deformity (not frail/low deformity; not frail/high deformity; frail/low deformity; frail/high deformity). Logistic regression assessed increasing invasiveness and outcomes [distal junctional failure (DJF), reoperation]. Within frailty/deformity groups, decision tree analysis assessed thresholds for an invasiveness cutoff above which experiencing a reoperation, DJF or not achieving Good Clinical Outcome was more likely.

RESULTS

A total of 115 patients were included. Frailty/deformity groups: 27% not frail/low deformity, 27% not frail/high deformity, 23.5% frail/low deformity, and 22.5% frail/high deformity. Logistic regression analysis found increasing invasiveness and occurrence of DJF [odds ratio (OR): 1.03, 95% CI: 1.01-1.05, P =0.002], and invasiveness increased with deformity severity ( P <0.05). Not frail/low deformity patients more often met Optimal Outcome with an invasiveness index <63 (OR: 27.2, 95% CI: 2.7-272.8, P =0.005). An invasiveness index <54 for the frail/low deformity group led to a higher likelihood of meeting the Optimal Outcome (OR: 9.6, 95% CI: 1.5-62.2, P =0.018). For the frail/high deformity group, patients with a score <63 had a higher likelihood of achieving Optimal Outcome (OR: 4.8, 95% CI: 1.1-25.8, P =0.033). There was no significant cutoff of invasiveness for the not frail/high deformity group.

CONCLUSIONS

Our study correlated increased invasiveness in CD surgery to the risk of DJF, reoperation, and poor clinical success. The thresholds derived for deformity severity and frailty may enable surgeons to individualize the invasiveness of their procedures during surgical planning to account for the heightened risk of adverse events and minimize unfavorable outcomes.

Revision-Free Loss of Sagittal Correction Greater Than Three Years After Adult Spinal Deformity Surgery: Who and Why?

STUDY DESIGN

Multicenter retrospective cohort study.

OBJECTIVE

To investigate risk factors for loss of correction within the instrumented lumbar spine after adult spinal deformity surgery.

SUMMARY OF BACKGROUND DATA

The sustainability of adult spinal deformity surgery remains a health care challenge. Malalignment is a major reason for revision surgery.

PATIENTS AND METHODS

A total of 321 patients who underwent fusion of the lumbar spine (≥5 levels, LIV pelvis) with a revision-free follow-up of ≥3 years were identified. Patients were stratified by a change in pelvic incidence-lumbar lordosis from 6 weeks to 3 years postoperative as "maintained" versus "loss" >5°. Those with instrumentation failure (broken rod, screw pullout, etc .) were excluded before comparisons. Demographics, surgical data, and radiographic alignment were compared. Repeated measure analysis of variance was performed to evaluate the maintenance of the correction for L1-L4 and L4-S1. Multivariate logistic regression was conducted to identify independent surgical predictors of correction loss.

RESULTS

The cohort had a mean age of 64 years, a mean Body Mass Index of 28 kg/m 2 , and 80% females. Eighty-two patients (25.5%) lost >5° of pelvic incidence-lumbar lordosis correction (mean loss 10±5°). After the exclusion of patients with instrumentation failure, 52 losses were compared with 222 maintained. Demographics, osteotomies, 3CO, interbody fusion, use of bone morphogenetic protein, rod material, rod diameter, and fusion length were not significantly different. L1-S1 screw orientation angle was 1.3 ± 4.1 from early postoperative to 3 years ( P = 0.031), but not appreciably different at L4-S1 (-0.1 ± 2.9 P = 0.97). Lack of a supplemental rod (odds ratio: 4.0, P = 0.005) and fusion length (odds ratio 2.2, P = 0.004) were associated with loss of correction.

CONCLUSIONS

Approximately, a quarter of revision-free patients lose an average of 10° of their 6-week correction by 3 years. Lordosis is lost proximally through the instrumentation ( i.e. tulip/shank angle shifts and/or rod bending). The use of supplemental rods and avoiding sagittal overcorrection may help mitigate this loss.

Lumbar Lordosis Redistribution and Segmental Correction in Adult Spinal Deformity (ASD): Does it Matter?

STUDY DESIGN

Retrospective analysis of prospectively collected data.

OBJECTIVE

Evaluate the impact of correcting to normative segmental lordosis values on post-operative outcomes.

BACKGROUND

Restoring lumbar lordosis magnitude is crucial in adult spinal deformity surgery, but the optimal location and segmental distribution remains unclear.

METHODS

Patients were grouped based on offset to normative segmental lordosis values, extracted from recent publications. Matched patients were within 10% of the cohort's mean offset, less than or over 10% were under- and over-corrected. Surgical technique, PROMs, and surgical complications were compared across groups at baseline and 2-year.

RESULTS

510 patients with an average age of 64.6, mean CCI 2.08, and average follow-up of 25 months. L4-5 was least likely to be matched (19.1%), while L4-S1 was the most likely (24.3%). More patients were overcorrected at proximal levels (T10-L2; Undercorrected, U: 32.2% vs. Matched, M: 21.7% vs. Overcorrected, O: 46.1%) and undercorrected at distal levels (L4-S1: U: 39.0% vs. M: 24.3% vs. O: 36.8%). Postoperative ODI was comparable across correction groups at all spinal levels except at L4-S1 and T10-L2/L4-S1, where overcorrected patients and matched were better than undercorrected (U: 32.1 vs. M: 25.4 vs. O: 26.5, P=0.005; U: 36.2 vs. M: 24.2 vs. O: 26.8, P=0.001; respectively). Patients overcorrected at T10-L2 experienced higher rates of proximal junctional failure (PJF) (U: 16.0% vs. M: 15.6% vs. O: 32.8%, P<0.001) and had greater posterior inclination of the upper instrumented vertebra (UIV) (U: -9.2±9.4° vs. M: -9.6±9.1° vs. O: -12.2±10.0°, P<0.001), whereas undercorrection at these levels led to higher rates of revision for implant failure (U: 14.2% vs. M: 7.3% vs. O: 6.4%, P=0.025).

CONCLUSIONS

Patients undergoing fusion for adult spinal deformity suffer higher rates of PJF with overcorrection and increased rates of implant failure with undercorrection based on normative segmental lordosis.

LEVEL OF EVIDENCE

IV.

Factors Influencing Maintenance of Alignment and Functional Improvement Following Adult Spinal Deformity Surgery: A 3-Year Outcome Analysis

STUDY DESIGN

This was a retrospective review.

OBJECTIVE

To assess the factors contributing to durability of surgical results following adult spinal deformity (ASD) surgery.

SUMMARY OF BACKGROUND

Factors contributing to the long-term sustainability of ASD correction are currently undefined.

MATERIALS AND METHODS

Operative ASD patients with preoperatively (baseline) and 3-year postoperatively radiographic/health-related quality of life data were included. At 1 and 3 years postoperatively, a favorable outcome was defined as meeting at least three of four criteria: (1) no proximal junctional failure or mechanical failure with reoperation, (2) best clinical outcome (BCO) for Scoliosis Research Society (SRS) (≥4.5) or Oswestry Disability Index (ODI) (<15), (3) improving in at least one SRS-Schwab modifier, and (4) not worsening in any SRS-Schwab modifier. A robust surgical result was defined as having a favorable outcome at both 1 and 3 years. Predictors of robust outcomes were identified using multivariable regression analysis with conditional inference tree for continuous variables.

RESULTS

We included 157 ASD patients in this analysis. At 1 year postoperatively, 62 patients (39.5%) met the BCO definition for ODI and 33 (21.0%) met the BCO for SRS. At 3 years, 58 patients (36.9%) had BCO for ODI and 29 (18.5%) for SRS. Ninety-five patients (60.5%) were identified as having a favorable outcome at 1 year postoperatively. At 3 years, 85 patients (54.1%) had a favorable outcome. Seventy-eight patients (49.7%) met criteria for a durable surgical result. Multivariable adjusted analysis identified the following independent predictors of surgical durability: surgical invasiveness >65, being fused to S1/pelvis, baseline to 6-week pelvic incidence and lumbar lordosis difference >13.9°, and having a proportional Global Alignment and Proportion score at 6 weeks.

CONCLUSIONS

Nearly 50% of the ASD cohort demonstrated good surgical durability, with favorable radiographic alignment and functional status maintained up to 3 years. Surgical durability was more likely in patients whose reconstruction was fused to the pelvis and addressed lumbopelvic mismatch with adequate surgical invasiveness to achieve full alignment correction.

Compensation from mild and severe cases of early proximal junctional kyphosis may manifest as progressive cervical deformity at two year follow-up

BACKGROUND

Postoperative reciprocal changes (RC) in the cervical spine associated with varying factors of proximal junctional kyphosis (PJK) following fusions of the thoracopelvic spine are poorly understood.

PURPOSE

Explore reciprocal changes in the cervical spine associated with varying factors (severity, progression, patient age) of PJK in patients undergoing adult spinal deformity (ASD) correction.

PATIENTS AND METHODS

Retrospective review of a multicenter ASD database.

INCLUSION

ASD patients > 18 y/o, undergoing fusions from the thoracic spine (UIV: T6-T12) to the pelvis with two-year radiographic data. ASD was defined as: Coronal Cobb angle ≥ 20°, Sagittal Vertical Axis ≥ 5 cm, Pelvic Tilt ≥ 25°, and/or Thoracic Kyphosis ≥ 60°. PJK was defined as a ≥ 10° measure of the sagittal Cobb angle between the inferior endplate of the UIV and the superior endplate of the UIV + 2. Patients were grouped by mild (M; 10°-20°) and severe (S; > 20°) PJK at one year. Propensity Score Matching (PSM) controlled for CCI, age, PI and UIV. Unpaired and paired t test analyses determined difference between RC parameters and change between time points. Pearson bi-variate correlations analyzed associations between RC parameters (T4-T12, TS-CL, cSVA, C2-Slope, and T1-Slope) and PJK descriptors.

RESULTS

284 ASD patients (UIV: T6: 1.1%; T7: 0.7%; T8: 4.6%; T9: 9.9%; T10: 58.8%; T11: 19.4%; T12: 5.6%) were studied. PJK analysis consisted of 182 patients (Mild = 91 and Severe = 91). Significant difference between M and S groups were observed in T4-T12 Δ1Y(- 16.8 v - 22.8, P = 0.001), TS-CLΔ1Y(- 0.6 v 2.8, P = 0.037), cSVAΔ1Y(- 1.8 v 1.9, P = 0.032), and C2 slopeΔ1Y(- 1.6 v 2.3, P = 0.022). By two years post-op, all changes in cervical alignment parameters were similar between mild and severe groups. Correlation between age and cSVAΔ1Y(R = 0.153, P = 0.034) was found. Incidence of severe PJK was found to correlate with TS-CLΔ1Y(R = 0.142, P = 0.049), cSVAΔ1Y(R = 0.171, P = 0.018), C2SΔ1Y(R = 0.148, P = 0.040), and T1SΔ2Y(R = 0.256, P = 0.003).

CONCLUSIONS

Compensation within the cervical spine differed between individuals with mild and severe PJK at one year postoperatively. However, similar levels of pathologic change in cervical alignment parameters were seen by two years, highlighting the progression of cervical compensation due to mild PJK over time. These findings provide greater evidence for the development of cervical deformity in individuals presenting with proximal junctional kyphosis.

Efficacy of Varying Surgical Approaches on Achieving Optimal Alignment in Adult Spinal Deformity Surgery

BACKGROUND

The Roussouly, SRS-Schwab, and Global Alignment and Proportion (GAP) classifications define alignment by spinal shape and deformity severity. The efficacy of different surgical approaches and techniques to successfully achieve these goals is not well understood.

PURPOSE

Identify the impact of surgical approach and/or technique on meeting complex realignment goals in adult spinal deformity (ASD) corrective surgery.

STUDY DESIGN/SETTING

Retrospective study.

MATERIALS AND METHODS

Included patients with ASD fused to pelvis with 2-year data. Patients were categorized by: (1) Roussouly: matching current and theoretical spinal shapes, (2) improving in SRS-Schwab modifiers (0, +, ++), and (3) improving GAP proportionality by 2 years. Analysis of covariance and multivariable logistic regression analyses controlling for age, levels fused, baseline deformity, and 3-column osteotomy usage compared the effect of different surgical approaches, interbody, and osteotomy use on meeting realignment goals.

RESULTS

A total of 693 patients with ASD were included. By surgical approach, 65.7% were posterior-only and 34.3% underwent anterior-posterior approach with 76% receiving an osteotomy (21.8% 3-column osteotomy). By 2 years, 34% matched Roussouly, 58% improved in GAP, 45% in SRS-Schwab pelvic tilt (PT), 62% sagittal vertical axis, and 70% pelvic incidence-lumbar lordosis. Combined approaches were most effective for improvement in PT [odds ratio (OR): 1.7 (1.1-2.5)] and GAP [OR: 2.2 (1.5-3.2)]. Specifically, anterior lumbar interbody fusion (ALIF) below L3 demonstrated higher rates of improvement versus TLIFs in Roussouly [OR: 1.7 (1.1-2.5)] and GAP [OR: 1.9 (1.3-2.7)]. Patients undergoing pedicle subtraction osteotomy at L3 or L4 were more likely to improve in PT [OR: 2.0 (1.0-5.2)] and pelvic incidence-lumbar lordosis [OR: 3.8 (1.4-9.8)]. Clinically, patients undergoing the combined approach demonstrated higher rates of meeting SCB in Oswestry Disability Index by 2 years while minimizing rates of proximal junctional failure, most often with an ALIF at L5-S1 [Oswestry Disability Index-SCB: OR: 1.4 (1.1-2.0); proximal junctional failure: OR: 0.4 (0.2-0.8)].

CONCLUSIONS

Among patients undergoing ASD realignment, optimal lumbar shape and proportion can be achieved more often with a combined approach. Although TLIFs, incorporating a 3-column osteotomy, at L3 and L4 can restore lordosis and normalize pelvic compensation, ALIFs at L5-S1 were most likely to achieve complex realignment goals with an added clinical benefit and mitigation of junctional failure.

How Much Lumbar Lordosis does a Patient Need to Reach their Age-Adjusted Alignment Target? A Formulated Approach Predicting Successful Surgical Outcomes

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Identify optimal lumbar lordosis in adult deformity correction to achieve age-adjusted targets and sustained alignment.

METHODS

Surgical adult spinal deformity patients reaching an age-adjusted ideal alignment at one year were identified. Multilinear regression analysis was used to identify the relationship between regional curvatures (LL and TK) that enabled achievement of a given global alignment (T1 pelvic angle, TPA) based on pelvic incidence (PI).

RESULTS

347 patients out of 1048 available reached their age-adjusted TPA within 5° (60-year-old, 72% women, body mass index 29 ± 6.2). They had a significant improvement in all sagittal parameters (except PI) from pre-operative baseline to 1 year following surgery (P < .001). Multilinear regression predicting L1-S1 based on TK, TPA, and PI demonstrated excellent results (R2 = .85). Simplification of the coefficients of prediction combined with a conversion to an age-based formula led to the following: LL = PI - 0.3TK - 0.5Age + 10. Internal validation of the formula led to a mean error of -.4°, and an absolute error of 5.0°. Internal validation on patients with an age-adjusted alignment revealed similar accuracy across the entire age-adjusted TPA spectrum (ranges of LL errors: ME = .2° to 1.7°, AE = 4.0° to 5.3°).

CONCLUSION

This study provides a simple guideline to identify the amount of LL needed to reach a given alignment (i.e., age-adjusted target) based on PI and associated TK. Implementation of this predictive formula during pre-operative surgical planning may help to reduce unexpected sub-optimal post-operative alignment outcomes.

Adult cervical spine deformity: a state-of-the-art review

Adult cervical deformity is a structural malalignment of the cervical spine that may present with variety of significant symptomatology for patients. There are clear and substantial negative impacts of cervical spine deformity, including the increased burden of pain, limited mobility and functionality, and interference with patients' ability to work and perform everyday tasks. Primary cervical deformities develop as the result of a multitude of different etiologies, changing the normal mechanics and structure of the cervical region. In particular, degeneration of the cervical spine, inflammatory arthritides and neuromuscular changes are significant players in the development of disease. Additionally, cervical deformities, sometimes iatrogenically, may present secondary to malalignment or correction of the thoracic, lumbar or sacropelvic spine. Previously, classification systems were developed to help quantify disease burden and influence management of thoracic and lumbar spine deformities. Following up on these works and based on the relationship between the cervical and distal spine, Ames-ISSG developed a framework for a standardized tool for characterizing and quantifying cervical spine deformities. When surgical intervention is required to correct a cervical deformity, there are advantages and disadvantages to both anterior and posterior approaches. A stepwise approach may minimize the drawbacks of either an anterior or posterior approach alone, and patients should have a surgical plan tailored specifically to their cervical deformity based upon symptomatic and radiographic indications. This state-of-the-art review is based upon a comprehensive overview of literature seeking to highlight the normal cervical spine, etiologies of cervical deformity, current classification systems, and key surgical techniques.

Determining the best vertebra for measuring pelvic incidence and spinopelvic parameters in adult spinal deformity patients with transitional anatomy

OBJECTIVE

The aim of this study was to determine if spinal deformity patients with L5 sacralization should have pelvic incidence (PI) and other spinopelvic parameters measured from the L5 or S1 endplate.

METHODS

This study was a multicenter retrospective comparative cohort study comprising a large database of adult spinal deformity (ASD) patients and a database of asymptomatic individuals. Linear regression modeling was used to determine normative T1 pelvic angle (TPA) and PI - lumbar lordosis (LL) mismatch (PI-LL) based on PI and age in a database of asymptomatic subjects. In an ASD database, patients with radiographic evidence of L5 sacralization had the PI, LL, and TPA measured from the superior endplate of S1 and then also from L5. The differences in TPA and PI-LL from normative were calculated in the sacralization cohort relative to L5 and S1 and correlated to the Oswestry Disability Index (ODI). Patients were grouped based on the Scoliosis Research Society (SRS)-Schwab PI-LL modifier (0, +, or ++) using the L5 PI-LL and S1 PI-LL. Baseline ODI and SF-36 Physical Component Summary (PCS) scores were compared across and within groups.

RESULTS

Among 1179 ASD patients, 276 (23.4%) had transitional anatomy, 176 with sacralized L5 (14.9%) and 100 (8.48%) with lumbarization of S1. The 176 patients with sacralized L5 were analyzed. When measured using the L5 superior endplate, pelvic parameters were significantly smaller than those measured relative to S1 (PI: 24.5° ± 11.0° vs 55.7° ± 12.0°, p = 0.001;TPA: 11.2° ± 12.0° vs 20.3° ± 12.5°, p = 0.001; and PI-LL: 0.67° ± 21.1° vs 11.4° ± 20.8°, p = 0.001). When measured from S1, 76 (43%), 45 (25.6%), and 55 (31.3%) patients had SRS-Schwab PI-LL modifiers of 0, +, and ++, respectively, compared with 124 (70.5%), 22 (12.5%), and 30 (17.0%), respectively, when measured from L5. There were significant differences in ODI and PCS scores as the SRS-Schwab grade increased regardless of L5 or S1 measurement. The L5 group had lower PCS functional scores for SRS-Schwab modifiers 0 and ++ relative to same grades in the S1 group. Offset from normative TPA (0.5° ± 11.1° vs 9.6° ± 10.8°, p = 0.001) and PI-LL (4.5° ± 20.4° vs 15.2° ± 19.3°, p = 0.001) were smaller when measuring from L5. Moreover, S1 measurements were more correlated with health status by ODI (TPA offset from normative: S1, R = 0.326 vs L5, R = 0.285; PI-LL offset from normative: S1, R = 0.318 vs L5, R = 0.274).

CONCLUSIONS

Measuring the PI and spinopelvic parameters at L5 in sacralized anatomy results in underestimating spinal deformity and is less correlated with health-related quality of life. Surgeons may consider measuring PI and spinopelvic parameters relative to S1 rather than at L5 in patients with a sacralized L5.

Cost Benefit of Implementation of Risk Stratification Models for Adult Spinal Deformity Surgery

STUDY DESIGN/SETTING

Retrospective cohort study.

OBJECTIVE

Assess the extent to which defined risk factors of adverse events are drivers of cost-utility in spinal deformity (ASD) surgery.

METHODS

ASD patients with 2-year (2Y) data were included. Tertiles were used to define high degrees of frailty, sagittal deformity, blood loss, and surgical time. Cost was calculated using the Pearl Diver registry and cost-utility at 2Y was compared between cohorts based on the number of risk factors present. Statistically significant differences in cost-utility by number of baseline risk factors were determined using ANOVA, followed by a generalized linear model, adjusting for clinical site and surgeon, to assess the effects of increasing risk score on overall cost-utility.

RESULTS

By 2 years, 31% experienced a major complication and 23% underwent reoperation. Patients with ≤2 risk factors had significantly less major complications. Patients with 2 risk factors improved the most from baseline to 2Y in ODI. Average cost increased by $8234 per risk factor (R2 = .981). Cost-per-QALY at 2Y increased by $122,650 per risk factor (R2 = .794). Adjusted generalized linear model demonstrated a significant trend between increasing risk score and increasing cost-utility (r2 = .408, P < .001).

CONCLUSIONS

The number of defined patient-specific and surgical risk factors, especially those with greater than two, were associated with increased index surgical costs and diminished cost-utility. Efforts to optimize patient physiology and minimize surgical risk would likely reduce healthcare expenditures and improve the overall cost-utility profile for ASD interventions.Level of evidence: III.

Predictive role of global spinopelvic alignment and upper instrumented vertebra level in symptomatic proximal junctional kyphosis in adult spinal deformity

OBJECTIVE

The authors of this study sought to evaluate the predictive role of global sagittal alignment and upper instrumented vertebra (UIV) level in symptomatic proximal junctional kyphosis (PJK) among patients with adult spinal deformity (ASD).

METHODS

Data on ASD patients who had undergone fusion of ≥ 5 vertebrae from 2008 to 2018 and with a minimum follow-up of 1 year were obtained from a prospectively collected multicenter database and evaluated (n = 1312). Radiographs were obtained preoperatively and at 6 weeks, 6 months, 1 year, 2 years, and 3 years postoperatively. The 22-Item Scoliosis Research Society Patient Questionnaire Revised (SRS-22r) scores were collected preoperatively, 1 year postoperatively, and 2 years postoperatively. Symptomatic PJK was defined as a kyphotic increase > 20° in the Cobb angle from the UIV to the UIV+2. At 6 weeks postoperatively, sagittal parameters were evaluated and patients were categorized by global alignment and proportion (GAP) score/category and SRS-Schwab sagittal modifiers. Patients were stratified by UIV level: upper thoracic (UT) UIV ≥ T8 or lower thoracic (LT) UIV ≤ T9.

RESULTS

Patients who developed symptomatic PJK (n = 260) had worse 1-year postoperative SRS-22r mental health (3.70 vs 3.86) and total (3.56 vs 3.67) scores, as well as worse 2-year postoperative self-image (3.45 vs 3.65) and satisfaction (4.03 vs 4.22) scores (all p ≤ 0.04). In the whole study cohort, patients with PJK had less pelvic incidence-lumbar lordosis (PI-LL) mismatch (-0.24° vs 3.29°, p < 0.001) but no difference in their GAP score/category or SRS-Schwab sagittal modifiers compared with the patients without PJK. Regression showed a higher risk of PJK with a pelvic tilt (PT) grade ++ (OR 2.35) and less risk with a PI-LL grade ++ (OR 0.35; both p < 0.01). When specifically analyzing the LT UIV cohort, patients with PJK had a higher GAP score (5.66 vs 4.79), greater PT (23.02° vs 20.90°), and less PI-LL mismatch (1.61° vs 4.45°; all p ≤ 0.02). PJK patients were less likely to be proportioned postoperatively (17.6% vs 30.0%, p = 0.015), and regression demonstrated a greater PJK risk with severe disproportion (OR 1.98) and a PT grade ++ (OR 3.15) but less risk with a PI-LL grade ++ (OR 0.45; all p ≤ 0.01). When specifically evaluating the UT UIV cohort, the PJK patients had less PI-LL mismatch (-2.11° vs 1.45°) but no difference in their GAP score/category. Regression showed a greater PJK risk with a PT grade + (OR 1.58) and a decreased risk with a PI-LL grade ++ (OR 0.21; both p < 0.05).

CONCLUSIONS

Symptomatic PJK leads to worse patient-reported outcomes and is associated with less postoperative PI-LL mismatch and greater postoperative PT. A worse postoperative GAP score and disproportion are only predictive of symptomatic PJK in patients with an LT UIV.

Economic burden of nonoperative treatment of adult spinal deformity

OBJECTIVE

The purpose of this study was to investigate the cost utility of nonoperative treatment for adult spinal deformity (ASD).

METHODS

Nonoperatively and operatively treated patients who met database criteria for ASD and in whom complete radiographic and health-related quality of life data at baseline and at 2 years were available were included. A cost analysis was completed on the PearlDiver database assessing the average cost of nonoperative treatment prior to surgical intervention based on previously published treatments (NSAIDs, narcotics, muscle relaxants, epidural steroid injections, physical therapy, and chiropractor). Utility data were calculated using the Oswestry Disability Index (ODI) converted to SF-6D with published conversion methods. Quality-adjusted life years (QALYs) used a 3% discount rate to account for residual decline in life expectancy (78.7 years). Minor and major comorbidities and complications were assessed according to the CMS.gov manual's definitions. Successful nonoperative treatment was defined as a gain in the minimum clinically importance difference (MCID) in both ODI and Scoliosis Research Society (SRS)-pain scores, and failure was defined as a loss in MCID or conversion to operative treatment. Patients with baseline ODI ≤ 20 and continued ODI of ≤ 20 at 2 years were considered nonoperative successful maintenance. The average utilization of nonoperative treatment and cost were applied to the ASD cohort.

RESULTS

A total of 824 patients were included (mean age 58.24 years, 81% female, mean body mass index 27.2 kg/m2). Overall, 75.5% of patients were in the operative and 24.5% were in the nonoperative cohort. At baseline patients in the operative cohort were significantly older, had a greater body mass index, increased pelvic tilt, and increased pelvic incidence-lumbar lordosis mismatch (all p < 0.05). With respect to deformity, patients in the operative group had higher rates of severe (i.e., ++) sagittal deformity according to SRS-Schwab modifiers for pelvic tilt, sagittal vertical axis, and pelvic incidence-lumbar lordosis mismatch (p < 0.05). At 2 years, patients in the operative cohort showed significantly increased rates of a gain in MCID for physical component summary of SF-36, ODI, and SRS-activity, SRS-pain, SRS-appearance, and SRS-mental scores. Cost analysis showed the average cost of nonoperative treatment 2 years prior to surgical intervention to be $2041. Overall, at 2 years patients in the nonoperative cohort had again in ODI of 0.36, did not show a gain in QALYs, and nonoperative treatment was determined to be cost-ineffective. However, a subset of patients in this cohort underwent successful maintenance treatment and had a decrease in ODI of 1.1 and a gain in utility of 0.006 at 2 years. If utility gained for this cohort was sustained to full life expectancy, patients' cost per QALY was $18,934 compared to a cost per QALY gained of $70,690.79 for posterior-only and $48,273.49 for combined approach in patients in the operative cohort.

CONCLUSIONS

Patients with ASD undergoing operative treatment at baseline had greater sagittal deformity and greater improvement in health-related quality of life postoperatively compared to patients treated nonoperatively. Additionally, patients in the nonoperative cohort overall had an increase in ODI and did not show improvement in utility gained. Patients in the nonoperative cohort who had low disability and sagittal deformity underwent successful maintenance and cost-effective treatment.

The impact of baseline cervical malalignment on the development of proximal junctional kyphosis following surgical correction of thoracolumbar adult spinal deformity

OBJECTIVE

The objective of this study was to identify the effect of baseline cervical deformity (CD) on proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in patients with adult spinal deformity (ASD).

METHODS

This study was a retrospective analysis of a prospectively collected, multicenter database comprising ASD patients enrolled at 13 participating centers from 2009 to 2018. Included were ASD patients aged > 18 years with concurrent CD (C2-7 kyphosis < -15°, T1S minus cervical lordosis > 35°, C2-7 sagittal vertical axis > 4 cm, chin-brow vertical angle > 25°, McGregor's slope > 20°, or C2-T1 kyphosis > 15° across any three vertebrae) who underwent surgery. Patients were grouped according to four deformity classification schemes: Ames and Passias CD modifiers, sagittal morphotypes as described by Kim et al., and the head versus trunk balance system proposed by Mizutani et al. Mean comparison tests and multivariable binary logistic regression analyses were performed to assess the impact of these deformity classifications on PJK and PJF rates up to 3 years following surgery.

RESULTS

A total of 712 patients with concurrent ASD and CD met the inclusion criteria (mean age 61.7 years, 71% female, mean BMI 28.2 kg/m2, and mean Charlson Comorbidity Index 1.90) and underwent surgery (mean number of levels fused 10.1, mean estimated blood loss 1542 mL, and mean operative time 365 minutes; 70% underwent osteotomy). By approach, 59% of the patients underwent a posterior-only approach and 41% underwent a combined approach. Overall, 277 patients (39.1%) had PJK by 1 year postoperatively, and an additional 189 patients (26.7%) developed PJK by 3 years postoperatively. Overall, 65 patients (9.2%) had PJF by 3 years postoperatively. Patients classified as having a cervicothoracic deformity morphotype had higher rates of early PJK than flat neck deformity and cervicothoracic deformity patients (p = 0.020). Compared with the head-balanced patients, trunk-balanced patients had higher rates of PJK and PJF (both p < 0.05). Examining Ames modifier severity showed that patients with moderate and severe deformity by the horizontal gaze modifier had higher rates of PJK (p < 0.001).

CONCLUSIONS

In patients with concurrent cervical and thoracolumbar deformities undergoing isolated thoracolumbar correction, the use of CD classifications allows for preoperative assessment of the potential for PJK and PJF that may aid in determining the correction of extending fusion levels.

Clinical outcomes and proximal junctional failure in adult spinal deformity patients corrected to normative alignment versus functional alignment

OBJECTIVE

The objective of this study was to explore the rate of proximal junctional failure (PJF) and functional outcomes of normative alignment goals compared with alignment targets based on age-appropriate physical function.

METHODS

Baseline relationships between age, pelvic incidence (PI), and a component of the T1 pelvic angle (TPA) within the fusion were analyzed in adult spinal deformity (ASD) patients and compared with those of asymptomatic patients. Linear regression modeling was used to determine alignment based on PI and age in asymptomatic patients (normative alignment), and in ASD patients, alignment corresponding to age-appropriate functional status (functional alignment). A cohort of 288 ASD patients was split into two groups based on whether the patient was closer to their normative or functional alignment goal at their 6-week postoperative radiographic follow-up. The rates of proximal junctional kyphosis (PJK) and PJF were determined for each cohort.

RESULTS

In the 288 ASD patients included in this pre- to postoperative analysis, there was no difference in baseline alignment or health-related quality of life (HRQOL) between the normative alignment and functional alignment groups. At 6 weeks, patients with normative alignment had a smaller TPA (4.45° vs 14.1°) and PI minus lumbar lordosis (-7.24° vs 7.4°) (both p < 0.0001) and higher PJK (40% vs 27.2%, p = 0.03) and PJF (17% vs 6.8%, p = 0.008) rates than patients with functional alignment.

CONCLUSIONS

Correction in ASD patients to normative alignment resulted in higher rates of PJK and PJF without improvements in HRQOL. Correction in ASD patients to functional alignment that mirrors the physical function of their age-matched asymptomatic peers is recommended.

Alterations in Magnitude and Shape of Thoracic Kyphosis Following Surgical Correction for Adult Spinal Deformity

STUDY DESIGN

Retrospective review of prospective multicenter data.

OBJECTIVES

This study aimed to investigate the shape of TK before and after fusion in ASD patients treated with long fusion.

METHODS

ASD patients undergoing posterior spinal fusions including at least T5 to L1 without prior fusion extending to the thoracic spine were included. Patients were categorized based on the preoperative T1-T12 kyphosis into: Hypo-TK (if < 30°), Normal-TK, and Hyper-TK (if > 70°). Regional kyphosis at T10-L1 (Distal), T5-T10 (Middle), and T1-T5 (Proximal) and their relative contributions to total kyphosis were compared between groups, and the pre-to postoperative changes were investigated using paired t test.

RESULTS

In total, 329 patients were included in this analysis (mean age: 57 ± 16 years, 79.6% female). Preoperative T1-T12 TK for the entire cohort was 40.9 ± 2° (32% Hypo-TK, 11% Hyper-TK, 57% Normal-TK). The Hypo-TK group had the smallest distal TK (5.9 vs 17.1 & 26.0), and middle TK (8.0 vs 25.3 & 45.4), but the percentage of contribution to total kyphosis was not significantly different (Distal: 24.1% vs 34.1% vs 32.8%; Middle: 46.6% vs 53.9% vs 56.8%, all P > .1). Postoperatively, T1-12 TK increased significantly (40.9 ± 2.0° vs 57.8 ± 17.6°). Each group had a decrease in distal kyphosis (Hypo-TK 2.6 ± 10.4°; Normal-TK 8.9 ± 11.5°; Hyper-TK 14.9 ± 12°, all P < .05). The middle kyphosis significantly decreased for Hyper-TK (11.8 ± 12.4) and increased for both Normal-TK and Hypo-TK (3.8 ± 11° and 14.2 ± 11°). Proximal TK increased significantly for all groups by 14-18°. Deterioration from Normal-TK to Hyper-TK postoperatively was associated with lower rate of patient satisfaction (59.6% vs 77.3%, P = .032).

CONCLUSIONS

Posterior spinal fusion for ASD alters the magnitude and shape of thoracic kyphosis. While 60% of patients had a normal TK at baseline, 30% of those patients developed iatrogenic hyperkyphosis postoperatively. Patients with baseline hypokyphosis were more likely to be corrected to normal TK than hyperkyphotic patients. Future research should investigate TK restoration in ASD and its impact on clinical outcomes and complications.

Analysis of Personalized Interbody Implants in the Surgical Treatment of Adult Spinal Deformity

STUDY DESIGN

Multicenter cohort.

OBJECTIVES

A report from the International Spine Study Group (ISSG) noted that surgeons failed to achieve alignment goals in nearly two-thirds of 266 complex adult deformity surgery (CADS) cases. We assess whether personalized interbody spacers are associated with improved rates of achieving goal alignment following adult spinal deformity (ASD) surgery.

METHODS

ASD patients were included if their surgery utilized 3D-printed personalized interbody spacer(s) and they met ISSG CADS inclusion criteria. Planned alignment was personalized by the surgeon during interbody planning. Planned vs achieved alignment was assessed and compared with the ISSG CADS series that used stock interbodies.

RESULTS

For 65 patients with personalized interbodies, 62% were women, mean age was 70.3 years (SD = 8.3), mean instrumented levels was 9.9 (SD = 4.1), and the mean number of personalized interbodies per patient was 2.2 (SD = .8). Segmental alignment was achieved close to plan for levels with personalized interbodies, with mean difference between goal and achieved as follows: intervertebral lordosis = .9° (SD = 5.2°), intervertebral coronal angle = .1° (SD = 4.7°), and posterior disc height = -0.1 mm (SD = 2.3 mm). Achieved pelvic incidence-to-lumbar lordosis mismatch (PI-LL) correlated significantly with goal PI-LL (r = .668, P < .001). Compared with the ISSG CADS cohort, utilization of personalized interbodies resulted in significant improvement in achieving PI-LL <5° of plan (P = .046) and showed a significant reduction in cases with PI-LL >15° of plan (P = .012).

CONCLUSIONS

This study supports use of personalized interbodies as a means of better achieving goal segmental sagittal and coronal alignment and significantly improving achievement of goal PI-LL compared with stock devices.

The Benefit of Addressing Malalignment in Revision Surgery for Proximal Junctional Kyphosis Following ASD Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Understand the benefit of addressing malalignment in revision surgery for proximal junctional kyphosis (PJK).

SUMMARY OF BACKGROUND DATA

PJK is a common cause of revision surgery for adult spinal deformity patients. During a revision, surgeons may elect to perform a proximal extension of the fusion, or also correct the source of the lumbopelvic mismatch.

MATERIALS AND METHODS

Recurrent PJK following revision surgery was the primary outcome. Revision surgical strategy was the primary predictor (proximal extension of fusion alone compared with combined sagittal correction and proximal extension). Multivariable logistic regression determined rates of recurrent PJK between the two surgical groups with lumbopelvic surgical correction assessed through improving ideal alignment in one or more alignment criteria [Global Alignment and Proportionality (GAP), Roussouly-type, and Sagittal Age-Adjusted Score (SAAS)].

RESULTS

A total of 151 patients underwent revision surgery for PJK. PJK occurred at a rate of 43.0%, and PJF at 12.6%. Patients proportioned in GAP postrevision had lower rates of recurrent PJK [23% vs. 42%; odds ratio (OR): 0.3, 95% confidence interval (CI): 0.1-0.8, P =0.024]. Following adjusted analysis, patients who were ideally aligned in one of three criteria (Matching in SAAS and/or Roussouly matched and/or achieved GAP proportionality) had lower rates of recurrent PJK (36% vs. 53%; OR: 0.4, 95% CI: 0.1-0.9, P =0.035) and recurrent PJF (OR: 0.1, 95% CI: 0.02-0.7, P =0.015). Patients ideally aligned in two of three criteria avoid any development of PJF (0% vs. 16%, P <0.001).

CONCLUSIONS

Following revision surgery for PJK, patients with persistent poor sagittal alignment showed increased rates of recurrent PJK compared with patients who had abnormal lumbopelvic alignment corrected during the revision. These findings suggest addressing the root cause of surgical failure in addition to proximal extension of the fusion may be beneficial.

Adult Cervical Deformity Patients Have Higher Baseline Frailty, Disability, and Comorbidities Compared With Complex Adult Thoracolumbar Deformity Patients: A Comparative Cohort Study of 616 Patients

STUDY DESIGN

Multicenter comparative cohort.

OBJECTIVE

Studies have shown markedly higher rates of complications and all-cause mortality following surgery for adult cervical deformity (ACD) compared with adult thoracolumbar deformity (ATLD), though the reasons for these differences remain unclear. Our objectives were to compare baseline frailty, disability, and comorbidities between ACD and complex ATLD patients undergoing surgery.

METHODS

Two multicenter prospective adult spinal deformity registries were queried, one ATLD and one ACD. Baseline clinical and frailty measures were compared between the cohorts.

RESULTS

616 patients were identified (107 ACD and 509 ATLD). These groups had similar mean age (64.6 vs 60.8 years, respectively, P = .07). ACD patients were less likely to be women (51.9% vs 69.5%, P < .001) and had greater Charlson Comorbidity Index (1.5 vs .9, P < .001) and ASA grade (2.7 vs 2.4, P < .001). ACD patients had worse VR-12 Physical Component Score (PCS, 25.7 vs 29.9, P < .001) and PROMIS Physical Function Score (33.3 vs 35.3, P = .031). All frailty measures were significantly worse for ACD patients, including hand dynamometer (44.6 vs 55.6 lbs, P < .001), CSHA Clinical Frailty Score (CFS, 4.0 vs 3.2, P < .001), and Edmonton Frailty Scale (EFS, 5.15 vs 3.21, P < .001). Greater proportions of ACD patients were frail (22.9% vs 5.7%) or vulnerable (15.6% vs 10.9%) based on EFS (P < .001).

CONCLUSIONS

Compared with ATLD patients, ACD patients had worse baseline characteristics on all measures assessed (comorbidities/disability/frailty). These differences may help account for greater risk of complications and all-cause mortality previously observed in ACD patients and facilitate strategies for better preoperative optimization.

When not to Operate in Spinal Deformity: Identifying Subsets of Patients With Simultaneous Clinical Deterioration, Major Complications, and Reoperation

STUDY DESIGN

Retrospective review of a prospectively enrolled adult spinal deformity (ASD) database.

OBJECTIVE

To investigate what patient factors elevate the risk of sub-optimal outcomes after deformity correction.

BACKGROUND

Currently, it is unknown what factors predict a poor outcome after adult spinal deformity surgery, which may require increased preoperative consideration and counseling.

MATERIALS AND METHODS

Patients >18 yrs undergoing surgery for ASD(scoliosis≥20°, SVA≥5 cm, PT≥25°, or TK≥60°). An unsatisfactory outcome was defined by the following categories met at two years: (1) clinical: deteriorating in ODI at two years follow-up (2) complications/reoperation: having a reoperation and major complication were deemed high risk for poor outcomes postoperatively (HR). Multivariate analyses assessed predictive factors of HR patients in adult spinal deformity patients.

RESULTS

In all, 633 adult spinal deformity (59.9 yrs, 79% F, 27.7 kg/m 2, CCI: 1.74) were included. Baseline severe Schwab modifier incidence (++): 39.2% pelvic incidence and lumbar lordosis, 28.8% sagittal vertical axis, 28.9% PT. Overall, 15.5% of patients deteriorated in ODI by two years, while 7.6% underwent reoperation and had a major complication. This categorized 11 (1.7%) as HR. HR were more comorbid in terms of arthritis (73%), heart disease (36%), and kidney disease (18%), P <0.001. Surgically, HR had greater EBL (4431ccs) and underwent more osteotomies (91%), specifically Ponte(36%) and Three Column Osteotomies(55%), which occurred more at L2(91%). HR underwent more PLIFs (45%) and had more blood transfusion units (2641ccs), all P <0.050. The multivariate regression determined a combination of a baseline Distress and Risk Assessment Method score in the 75th percentile, having arthritis and kidney disease, a baseline right lower extremity motor score ≤3, cSVA >65 mm, C2 slope >30.2°, CTPA >5.5° for an R2 value of 0.535 ( P <0.001).

CONCLUSIONS

When addressing adult spine deformities, poor outcomes tend to occur in severely comorbid patients with major baseline psychological distress scores, poor neurologic function, and concomitant cervical malalignment.

Are we improving in the optimization of surgery for high-risk adult cervical spine deformity patients over time?

OBJECTIVE

The aim of this study was to investigate whether surgery for high-risk patients is being optimized over time and if poor outcomes are being minimized.

METHODS

Patients who underwent surgery for cervical deformity (CD) and were ≥ 18 years with baseline and 2-year data were stratified by year of surgery from 2013 to 2018. The cohort was divided into two groups based on when the surgery was performed. Patients in the early cohort underwent surgery between 2013 and 2015 and those in the recent cohort underwent surgery between 2016 and 2018. High-risk patients met at least 2 of the following criteria: 1) baseline C2-7 Cobb angle > 15°, mismatch between T1 slope and cervical lordosis ≥ 35°, C2-7 sagittal vertical axis > 4 cm, or chin-brow vertical angle > 25°; 2) age ≥ 70 years; 3) severe baseline frailty (Miller index); 4) Charlson Comorbidity Index (CCI) ≥ 1 SD above the mean; 5) three-column osteotomy as treatment; and 6) fusion > 10 levels or > 7 levels for elderly patients. The mean comparison analysis assessed differences between groups. Stepwise multivariable linear regression described associations between increasing year of surgery and complications.

RESULTS

Eighty-two CD patients met high-risk criteria (mean age 62.11 ± 10.87 years, 63.7% female, mean BMI 29.70 ± 8.16 kg/m2, and mean CCI 1.07 ± 1.45). The proportion of high-risk patients increased with time, with 41.8% of patients in the early cohort classified as high risk compared with 47.6% of patients in the recent cohort (p > 0.05). Recent high-risk patients were more likely to be female (p = 0.008), have a lower BMI (p = 0.038), and have a higher baseline CCI (p = 0.013). Surgically, high-risk patients in the recent cohort were more likely to undergo low-grade osteotomy (p = 0.003). By postoperative complications, recent high-risk patients were less likely to experience any postoperative adverse events overall (p = 0.020) or complications such as dysphagia (p = 0.045) at 2 years. Regression analysis revealed increasing year of surgery to be correlated with decreasing minor complication rates (p = 0.030), as well as lowered rates of distal junctional kyphosis by 2 years (p = 0.048).

CONCLUSIONS

Over time, high-risk CD patients have an increase in frequency and comorbidity rates but have demonstrated improved postoperative outcomes. These findings suggest that spine surgeons have improved over time in optimizing selection and reducing potential adverse events in high-risk patients.

Adherence to the Obeid coronal malalignment classification and a residual malalignment below 20 mm can improve surgical outcomes in adult spine deformity surgery

PURPOSE

Coronal balance is a major factor impacting the surgical outcomes in adult spinal deformity (ASD). The Obeid coronal malalignment (O-CM) classification has been proposed to improve the coronal alignment in ASD surgery. Aim of this study was to investigate whether a postoperative CM < 20 mm and adherence to the O-CM classification could improve surgical outcomes and decrease the rate of mechanical failure in a cohort of ASD patients.

METHODS

Multicenter retrospective analysis of prospectively collected data on all ASD patients who underwent surgical management and had a preoperative CM > 20 mm and a 2-year follow-up. Patients were divided in two groups according to whether or not surgery had been performed in adherence to the guidelines of the O-CM classification and according to whether or not the residual CM was < 20 mm. The outcomes of interest were radiographic data, rate of mechanical complications and Patient-Reported Outcome Measures.

RESULTS

At 2 years, adherence to the O-CM classification led to a lower rate of mechanical complications (40 vs. 60%). A coronal correction of the CM < 20 mm allowed for a significant improvement in SRS-22 and SF-36 scores and was associated with a 3.5 times greater odd of achieving the minimal clinical important difference for the SRS-22.

CONCLUSION

Adherence to the O-CM classification could reduce the risk of mechanic complications 2 years after ASD surgery. Patients with a residual CM < 20 mm showed better functional outcomes and a 3.5 times greater odd of achieving the MCID for the SRS-22 score.

Impact of Frailty on the Development of Proximal Junctional Failure: Does Frailty Supersede Achieving Optimal Realignment?

BACKGROUND

Patients undergoing surgery for adult spinal deformity (ASD) are often elderly, frail, and at elevated risk of adverse events perioperatively, with proximal junctional failure (PJF) occurring relatively frequently. Currently, the specific role of frailty in potentiating this outcome is poorly defined.

PURPOSE

To determine if the benefits of optimal realignment in ASD, with respect to the development of PJF, can be offset by increasing frailty.

STUDY DESIGN

Retrospective cohort.

MATERIALS AND METHODS

Operative ASD patients (scoliosis >20°, SVA>5 cm, pelvic tilt>25°, or TK>60°) fused to the pelvis or below with available baseline and 2-year (2Y) radiographic and HRQL data were included. The Miller Frailty Index (FI) was used to stratify patients into 2 categories: Not Frail (FI <3) and Frail (>3). Proximal Junctional Failure (PJF) was defined using the Lafage criteria. "Matched" and "unmatched" refers to ideal age-adjusted alignment postoperatively. Multivariable regression determined the impact of frailty on the development of PJF.

RESULTS

Two hundred eighty-four ASD patients met inclusion criteria [62.2yrs±9.9, 81%F, BMI: 27.5 kg/m 2 ±5.3, ASD-FI: 3.4±1.5, Charlson Comorbidity Index (CCI): 1.7±1.6]. Forty-three percent of patients were characterized as Not Frail (NF) and 57% were characterized as Frail (F). PJF development was lower in the NF group compared with the F group (7% vs . 18%; P =0.002). F patients had 3.2 × higher risk of PJF development compared to NF patients (OR: 3.2, 95% CI: 1.3-7.3, P =0.009). Controlling for baseline factors, F unmatched patients had a higher degree of PJF (OR: 1.4, 95% CI:1.02-1.8, P =0.03); however, with prophylaxis, there was no increased risk. Adjusted analysis shows F patients, when matched postoperatively in PI-LL, had no significantly higher risk of PJF.

CONCLUSIONS

An increasingly frail state is significantly associated with the development of PJF after corrective surgery for ASD. Optimal realignment may mitigate the impact of frailty on eventual PJF. Prophylaxis should be considered in frail patients who do not reach ideal alignment goals.