Browsing by Author "Lenke, Lawrence"
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Item Open Access Activity and sports resumption after long segment fusions to the pelvis for adult spinal deformity: survey results of AO Spine members.(Spine deformity, 2023-07) Theologis, Alekos A; Cummins, Daniel D; Kato, So; Lewis, Stephen; Shaffrey, Christopher; Lenke, Lawrence; Berven, Sigurd H; AO Spine Knowledge Forum DeformityPurpose
To assess recommendations for when adult spinal deformity (ASD) patients may return to athletic activities after surgery.Methods
A web-based survey was administered to members of AO Spine. The survey consisted of surgeon demographic information and questions asking when a patient undergoing a long thoracolumbar fusion (> 5 levels) with pelvic fixation for ASD would be allowed to resume unrestricted range of motion (ROM), non-contact sports, and contact sports postoperatively. Ordinal logistic regression was used to determine predictors for time to resume each activity.Results
One hundred twenty four members' responses were included for analysis. The majority of respondents would allow unrestricted ROM within 3 months postop (< 3 months: 81% vs > 3 months: 19%]. For when to return to non-contact sports, the most common responses were "2-3 months" (26.6%), "3-4 months" (26.6%), and "6-12 months" (18.5%). For when to return to contact sports, the majority advised > 4 months postop [> 4 months: "4-6 months" (19.2%), "6-12 months" (28.0%), " > 12 months" (28.8%) versus < 4 months: "1-2 months" (4.0%), "2-3 months" (1.6%), "3-4 months" (8.8%)]. 8.8% responded they would "never" allow resumption of contact sports.Conclusion
There was significant variation between surgeons' recommendations for resumption of unrestricted range of motion and sports following long fusion with pelvic fixation for ASD. An evidence-based approach to activity recommendations will require information on outcomes and complications.Item Open Access Calibration of a comprehensive predictive model for the development of proximal junctional kyphosis and failure in adult spinal deformity patients with consideration of contemporary goals and techniques.(Journal of neurosurgery. Spine, 2023-06) Tretiakov, Peter S; Lafage, Renaud; Smith, Justin S; Line, Breton G; Diebo, Bassel G; Daniels, Alan H; Gum, Jeffrey; Protopsaltis, Themistocles; Hamilton, D Kojo; Soroceanu, Alex; Scheer, Justin K; Eastlack, Robert K; Mundis, Gregory; Nunley, Pierce D; Klineberg, Eric O; Kebaish, Khaled; Lewis, Stephen; Lenke, Lawrence; Hostin, Richard; Gupta, Munish C; Ames, Christopher P; Hart, Robert A; Burton, Douglas; Shaffrey, Christopher I; Schwab, Frank; Bess, Shay; Kim, Han Jo; Lafage, Virginie; Passias, Peter GObjective
The objective of this study was to calibrate an updated predictive model incorporating novel clinical, radiographic, and prophylactic measures to assess the risk of proximal junctional kyphosis (PJK) and failure (PJF).Methods
Operative patients with adult spinal deformity (ASD) and baseline and 2-year postoperative data were included. PJK was defined as ≥ 10° in sagittal Cobb angle between the inferior uppermost instrumented vertebra (UIV) endplate and superior endplate of the UIV + 2 vertebrae. PJF was radiographically defined as a proximal junctional sagittal Cobb angle ≥ 15° with the presence of structural failure and/or mechanical instability, or PJK with reoperation. Backstep conditional binary supervised learning models assessed baseline demographic, clinical, and surgical information to predict the occurrence of PJK and PJF. Internal cross validation of the model was performed via a 70%/30% cohort split. Conditional inference tree analysis determined thresholds at an alpha level of 0.05.Results
Seven hundred seventy-nine patients with ASD (mean 59.87 ± 14.24 years, 78% female, mean BMI 27.78 ± 6.02 kg/m2, mean Charlson Comorbidity Index 1.74 ± 1.71) were included. PJK developed in 50.2% of patients, and 10.5% developed PJF by their last recorded visit. The six most significant demographic, radiographic, surgical, and postoperative predictors of PJK/PJF were baseline age ≥ 74 years, baseline sagittal age-adjusted score (SAAS) T1 pelvic angle modifier > 1, baseline SAAS pelvic tilt modifier > 0, levels fused > 10, nonuse of prophylaxis measures, and 6-week SAAS pelvic incidence minus lumbar lordosis modifier > 1 (all p < 0.015). Overall, the model was deemed significant (p < 0.001), and internally validated receiver operating characteristic analysis returned an area under the curve of 0.923, indicating robust model fit.Conclusions
PJK and PJF remain critical concerns in ASD surgery, and efforts to reduce the occurrence of PJK and PJF have resulted in the development of novel prophylactic techniques and enhanced clinical and radiographic selection criteria. This study demonstrates a validated model incorporating such techniques that may allow for the prediction of clinically significant PJK and PJF, and thus assist in optimizing patient selection, enhancing intraoperative decision making, and reducing postoperative complications in ASD surgery.Item Open Access Cervical mismatch: the normative value of T1 slope minus cervical lordosis and its ability to predict ideal cervical lordosis.(Journal of neurosurgery. Spine, 2018-10) Staub, Blake N; Lafage, Renaud; Kim, Han Jo; Shaffrey, Christopher I; Mundis, Gregory M; Hostin, Richard; Burton, Douglas; Lenke, Lawrence; Gupta, Munish C; Ames, Christopher; Klineberg, Eric; Bess, Shay; Schwab, Frank; Lafage, Virginie; International Spine Study GroupOBJECTIVE: Numerous studies have attempted to delineate the normative value for T1S-CL (T1 slope minus cervical lordosis) as a marker for both cervical deformity and a goal for correction similar to how PI-LL (pelvic incidence-lumbar lordosis) mismatch informs decision making in thoracolumbar adult spinal deformity (ASD). The goal of this study was to define the relationship between T1 slope (T1S) and cervical lordosis (CL). METHODS: This is a retrospective review of a prospective database. Surgical ASD cases were initially analyzed. Analysis across the sagittal parameters was performed. Linear regression analysis based on T1S was used to provide a clinically applicable equation to predict CL. Findings were validated using the postoperative alignment of the ASD patients. Further validation was then performed using a second, normative database. The range of normal alignment associated with horizontal gaze was derived from a multilinear regression on data from asymptomatic patients. RESULTS: A total of 103 patients (mean age 54.7 years) were included. Analysis revealed a strong correlation between T1S and C0-7 lordosis (r = 0.886), C2-7 lordosis (r = 0.815), and C0-2 lordosis (r = 0.732). There was no significant correlation between T1S and T1S-CL. Linear regression analysis revealed that T1S-CL assumed a constant value of 16.5° (R2 = 0.664, standard error 2°). These findings were validated on the postoperative imaging (mean absolute error [MAE] 5.9°). The equation was then applied to the normative database (MAE 6.7° controlling for McGregor slope [MGS] between -5° and 15°). A multilinear regression between C2-7, T1S, and MGS demonstrated a range of T1S-CL between 14.5° and 26.5° was necessary to maintain horizontal gaze. CONCLUSIONS: Normative CL can be predicted via the formula CL = T1S - 16.5° ± 2°. This implies a threshold of deformity and aids in providing a goal for surgical correction. Just as pelvic incidence (PI) can be used to determine the ideal LL, T1S can be used to predict ideal CL. This formula also implies that a kyphotic cervical alignment is to be expected for individuals with a T1S < 16.5°.Item Open Access Determining the best vertebra for measuring pelvic incidence and spinopelvic parameters in adult spinal deformity patients with transitional anatomy.(Journal of neurosurgery. Spine, 2023-10) Ani, Fares; Protopsaltis, Themistocles S; Parekh, Yesha; Odeh, Khalid; Lafage, Renaud; Smith, Justin S; Eastlack, Robert K; Lenke, Lawrence; Schwab, Frank; Mundis, Gregory M; Gupta, Munish C; Klineberg, Eric O; Lafage, Virginie; Hart, Robert; Burton, Douglas; Ames, Christopher P; Shaffrey, Christopher I; Bess, ShayObjective
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.Item Open Access Quantifying the Contribution of Lower Limb Compensation to Upright Posture: What Happens if Adult Spinal Deformity Patients Do Not Compensate?(Spine, 2023-03) Lafage, Renaud; Duvvuri, Priya; Elysee, Jonathan; Diebo, Bassel; Bess, Shay; Burton, Douglas; Daniels, Alan; Gupta, Munish; Hostin, Richard; Kebaish, Khaled; Kelly, Michael; Kim, Han Jo; Klineberg, Eric; Lenke, Lawrence; Lewis, Stephen; Ames, Christopher; Passias, Peter; Protopsaltis, Themistocles; Shaffrey, Christopher; Smith, Justin S; Schwab, Frank; Lafage, Virginie; International Spine Study GroupStudy design
This is a multicenter, prospective cohort study.Objective
This study tests the hypothesis that elimination of lower limb compensation in patients with adult spinal deformity (ASD) will significantly increase the magnitude of sagittal malalignment.Summary of background data
ASD affects a significant proportion of the elderly population, impairing functional sagittal alignment and inhibiting overall quality of life. To counteract these effects, patients with ASD use their spine, pelvis, and lower limbs to create a compensatory posture that allows for standing and mobility. However, the degree to which each of the hips, knees, and ankles contributes to these compensatory mechanisms has yet to be determined.Methods
Patients undergoing corrective surgery for ASD were included if they met at least one of the following criteria: complex surgical procedure, geriatric deformity surgery, or severe radiographic deformity. Preoperative full-body x-rays were evaluated, and age and PI-adjusted normative values were used to model spine alignment based upon three positions: compensated (all lower extremity compensatory mechanisms maintained), partially compensated (removal of ankle dorsiflexion and knee flexion, with maintained hip extension), and uncompensated (ankle, knee, and hip compensation set to the age and PI norms).Results
288 patients were included (mean age 60 y, 70.5% females). As the model transitioned from the compensated to uncompensated position, initial posterior translation of the pelvis decreased significantly to an anterior translation versus the ankle (P.Shift: 30 to -7.6 mm). This was associated with a decrease in pelvic retroversion (PT: 24.1 to 16.1), hip extension (SFA: 203 to 200), knee flexion (KA: 5.5 to-0.4), and ankle dorsiflexion (AA: 5.3 to 3.7). As a result, the anterior malalignment of the trunk significantly increased: SVA (65 to 120 mm) and G-SVA (C7-Ankle from 36 to 127 mm).Conclusion
Removal of lower limbs compensation revealed an unsustainable truncal malalignment with two-fold greater SVA.Item Open Access The comprehensive anatomical spinal osteotomy classification.(Neurosurgery, 2014-01) Schwab, Frank; Blondel, Benjamin; Chay, Edward; Demakakos, Jason; Lenke, Lawrence; Tropiano, Patrick; Ames, Christopher; Smith, Justin S; Shaffrey, Christopher I; Glassman, Steven; Farcy, Jean-Pierre; Lafage, VirginieBackground
Global sagittal malalignment is significantly correlated with health-related quality-of-life scores in the setting of spinal deformity. In order to address rigid deformity patterns, the use of spinal osteotomies has seen a substantial increase. Unfortunately, variations of established techniques and hybrid combinations of osteotomies have made comparisons of outcomes difficult.Objective
To propose a classification system of anatomically-based spinal osteotomies and provide a common language among spine specialists.Methods
The proposed classification system is based on 6 anatomic grades of resection (1 through 6) corresponding to the extent of bone resection and increasing degree of destabilizing potential. In addition, a surgical approach modifier is added (posterior approach or combined anterior and posterior approaches). Reliability of the classification system was evaluated by an analysis of 16 clinical cases, rated 2 times by 8 different readers, and calculation of Fleiss kappa coefficients.Results
Intraobserver reliability was classified as "almost perfect"; Fleiss kappa coefficient averaged 0.96 (range, 0.92-1.0) for resection type and 0.90 (0.71-1.0) for the approach modifier. Results from the interobserver reliability for the classification were 0.96 for resection type and 0.88 for the approach modifier.Conclusion
This proposed anatomically based classification system provides a consistent description of the various osteotomies performed in spinal deformity correction surgery. The reliability study confirmed that the classification is simple and consistent. Further development of its use will provide a common frame for osteotomy assessment and permit comparative analysis of different treatments.Item Open Access The comprehensive anatomical spinal osteotomy classification.(Neurosurgery, 2015-03) Schwab, Frank; Blondel, Benjamin; Chay, Edward; Demakakos, Jason; Lenke, Lawrence; Tropiano, Patrick; Ames, Christopher; Smith, Justin S; Shaffrey, Christopher I; Glassman, Steven; Farcy, Jean-Pierre; Lafage, VirginieBackground
Global sagittal malalignment is significantly correlated with health-related quality-of-life scores in the setting of spinal deformity. In order to address rigid deformity patterns, the use of spinal osteotomies has seen a substantial increase. Unfortunately, variations of established techniques and hybrid combinations of osteotomies have made comparisons of outcomes difficult.Objective
To propose a classification system of anatomically-based spinal osteotomies and provide a common language among spine specialists.Methods
The proposed classification system is based on 6 anatomic grades of resection (1 through 6) corresponding to the extent of bone resection and increasing degree of destabilizing potential. In addition, a surgical approach modifier is added (posterior approach or combined anterior and posterior approaches). Reliability of the classification system was evaluated by an analysis of 16 clinical cases, rated 2 times by 8 different readers, and calculation of Fleiss kappa coefficients.Results
Intraobserver reliability was classified as 'almost perfect'; Fleiss kappa coefficient averaged 0.96 (range, 0.92-1.0) for resection type and 0.90 (0.71-1.0) for the approach modifier. Results from the interobserver reliability for the classification were 0.96 for resection type and 0.88 for the approach modifier.Conclusion
This proposed anatomically based classification system provides a consistent description of the various osteotomies performed in spinal deformity correction surgery. The reliability study confirmed that the classification is simple and consistent. Further development of its use will provide a common frame for osteotomy assessment and permit comparative analysis of different treatments.Item Open Access The Scoliosis Research Society Health-Related Quality of Life (SRS-30) age-gender normative data: an analysis of 1346 adult subjects unaffected by scoliosis.(Spine, 2011-06) Baldus, Christine; Bridwell, Keith; Harrast, John; Shaffrey, Christopher; Ondra, Stephen; Lenke, Lawrence; Schwab, Frank; Mardjetko, Steven; Glassman, Steven; Edwards, Charles; Lowe, Thomas; Horton, William; Polly, DavidStudy design
Prospective, cross-sectional study.Objective
To determine Scoliosis Research Society (SRS)-30 health-related quality of life (HRQOL) reference values by age and gender in an adult population unaffected by scoliosis thereby allowing clinicians and investigators to compare individual and/or groups of spinal deformity patients to their generational peers.Summary of background data
Normative data are collected to establish means and standard deviations of health-related quality of life outcomes representative of a population. The SRS HRQOL questionnaire has become the standard for determining and comparing treatment outcomes in spinal deformity practices. With the establishment of adult SRS-30 HRQOL population values, clinicians, and investigators now have a reference for interpretation of individual scores and/or the scores of subgroups of adult patients with spinal deformities.Methods
The SRS-30 HRQOL was issued prospectively to 1346 adult volunteers recruited from across the United States. Volunteers self-reported no history of scoliosis or prior spine surgery. Domain medians, means, confidence intervals, percentiles, and minimum/maximum values were calculated for six generational age-gender groups: male/female; 20-39, 40-59, and 60-80 years of age.Results
Median and mean domain values ranged from 4.1 to 4.6 for all age-gender groups. The older the age-gender group, the lower (worse) the reported domain median and mean scores. The only exception was the mental health domain scores in the female groups which improved slightly. Males reported higher (better) scores than females but only the younger males were significantly higher in all domains than their female counterparts. In addition, all male groups reported higher Mental Health domain scores than their female counterparts (P=0.003).Conclusion
This study reports population medians, means, standard deviations, percentiles, and confidence intervals for the domains of the SRS-30 HRQOL instrument. Clinicians must be mindful of age-gender differences when assessing deformity populations. Generational decreases noted in the older adult volunteer scores may provide a basis for future investigators to interpret observed score decreases in patient cohorts at long-term follow-up.