How to determine the optimal proximal fusion level for Scheuermann kyphosis

OBJECTIVE

To determine optimal proximal fusion levels for instrumented spinal fusion for Scheuermann kyphosis.

METHODS

We reviewed 86 patients (33 women) who underwent corrective instrumented spinal fusion for Scheuermann kyphosis. All patients had long-cassette upright lateral radiographs taken preoperatively, postoperatively, and at 2 years and the last follow-up. Demographic, radiographic, and surgical parameters were compared between patients with and without PJK.

RESULTS

PJK occurred in 28 patients (32%). The mean maximum Cobb angle was 85.8° ± 11.7° preoperatively, 54.8° ± 14.2° postoperatively, and 59.7° ± 16.8° at the last follow-up. Age and sex did not differ between the PJK and non-PJK groups (P > 0.05). The preoperative curve characteristics, fusion levels, and corrective ratio were similar in both groups (P > 0.05). The maximal Cobb angle at 2 years and the last follow-up significantly differed between the 2 groups (P < 0.05). The proportion of patients with the uppermost instrumented vertebra (UIV) at or above the proximal end vertebra (PEV) was similar in both groups (P > 0.05). The proportion of patients with UIV at or above T2 was significantly greater in the non-PJK group (P < 0.05). PJK was significantly associated with a C7 plumb line (C7PL)-sacrum distance ≥ 50 mm (P < 0.05).

CONCLUSION

PJK is the main cause of postoperative correction loss. Proper fusion-level selection can reduce PJK occurrence. We recommend having the UIV at T2 or above, especially when the C7PL-sacrum distance ≥ 50 mm.

Failure of nonoperative care in adult symptomatic lumbar scoliosis: incidence, timing, and risk factors for conversion from nonoperative to operative treatment

OBJECTIVE

The Adult Symptomatic Lumbar Scoliosis (ASLS) study is a prospective multicenter trial with randomized and observational cohorts comparing operative and nonoperative treatment for ASLS. The objective of the present study was to perform a post hoc analysis of the ASLS trial to examine factors related to failure of nonoperative treatment in ASLS.

METHODS

Patients from the ASLS trial who initially received at least 6 months of nonoperative treatment were followed for up to 8 years after trial enrollment. Baseline patient-reported outcome measures (Scoliosis Research Society-22 [SRS-22] questionnaire and Oswestry Disability Index), radiographic data, and other clinical characteristics were compared between patients who did and did not convert to operative treatment during follow-up. The incidence of operative treatment was calculated and independent predictors of operative treatment were identified using multivariate regression.

RESULTS

Of 135 nonoperative patients, 42 (31%) crossed over to operative treatment after 6 months and 93 (69%) received only nonoperative treatment. In the observational cohort, 23 (22%) of 106 nonoperative patients crossed over to surgery. In the randomized cohort, 19 (66%) of 29 patients randomized to nonoperative treatment crossed over to surgery. The most impactful factors associated with crossover from nonoperative to operative treatment were enrollment in the randomized cohort and baseline SRS-22 subscore < 3.0 at the 2-year follow-up, closer to 3.4 at 8 years. In addition, baseline lumbar lordosis (LL) < 50° was associated with crossover to operative treatment. Each 1-point decrease in baseline SRS-22 subscore was associated with a 233% higher risk of conversion to surgery (hazard ratio [HR] 2.33, 95% confidence interval [CI] 1.14-4.76, p = 0.0212). Each 10° decrease in LL was associated with a 24% increased risk of conversion to operative treatment (HR 1.24, 95% CI 1.03-1.49, p = 0.0232). Enrollment in the randomized cohort was associated with a 337% higher probability of proceeding with operative treatment (HR 3.37, 95% CI 1.54-7.35, p = 0.0024).

CONCLUSIONS

Enrollment in the randomized cohort, a lower baseline SRS-22 subscore, and lower LL were associated with conversion from nonoperative treatment to surgery in patients (observational and randomized) who were initially managed nonoperatively in the ASLS trial.

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.

Proximal junctional failure in primary thoracolumbar fusion/fixation to the sacrum/pelvis for adult symptomatic lumbar scoliosis: long-term follow-up of a prospective multicenter cohort of 160 patients

OBJECTIVE

Proximal junctional failure (PJF) is a severe form of proximal junctional kyphosis. Previous reports on PJF have been limited by heterogeneous cohorts and relatively short follow-ups. The authors' objectives herein were to identify risk factors for PJF and to assess its long-term incidence and revision rates in a homogeneous cohort.

METHODS

The authors reviewed data from the Adult Symptomatic Lumbar Scoliosis 1 trial (ASLS-1), a National Institutes of Health-sponsored prospective multicenter study. Inclusion criteria were an age ≥ 40 years, ASLS (Cobb angle ≥ 30° and Oswestry Disability Index [ODI] ≥ 20 or Scoliosis Research Society revised 22-item questionnaire [SRS-22r] score ≤ 4.0 in pain, function, or self-image domains), and primary thoracolumbar fusion/fixation to the sacrum/pelvis of ≥ 7 levels. PJF was defined as a postoperative proximal junctional angle (PJA) change > 20°, fracture of the uppermost instrumented vertebra (UIV) or UIV+1 with > 20% vertebral height loss, spondylolisthesis of UIV/UIV+1 > 3 mm, or UIV screw dislodgment.

RESULTS

One hundred sixty patients (141 women) were included in this analysis and had a median age of 62 years and a mean follow-up of 4.3 years (range 0.1-6.1 years). Forty-six patients (28.8%) had PJF at a median of 0.92 years (IQR 0.14, 1.23 years) following surgery. Based on Kaplan-Meier analyses, PJF rates at 1, 2, 3, and 4 years were 14.4%, 21.9%, 25.9%, and 27.4%, respectively. On univariate analysis, PJF was associated with greater age (p = 0.0316), greater body mass index (BMI; p = 0.0319), worse baseline patient-reported outcome measures (PROMs; ODI, SRS-22r, and SF-12 Physical Component Summary [PCS]; all p < 0.04), the use of posterior column osteotomies (PCOs; p = 0.0039), and greater postoperative thoracic kyphosis (TK; p = 0.0031) and PJA (p < 0.001). The use of UIV hooks was protective against PJF (p = 0.0340). On regression analysis (without postoperative measures), PJF was associated with greater BMI (HR 1.077, 95% CI 1.007-1.153, p = 0.0317), lower preoperative PJA (HR 0.607, 95% CI 0.407-0.906, p = 0.0146), and greater preoperative TK (HR 1.362, 95% CI 1.082-1.715, p = 0.0085). Patients with PJF had worse PROMs at the last follow-up (ODI, SRS-22r subscore and self-image, and SF-12 PCS; p < 0.04). Sixteen PJF patients (34.8%) underwent revision, and PJF recurred in 3 (18.8%).

CONCLUSIONS

Among 160 primary ASLS patients with a median age of 62 years and predominant coronal deformity, the PJF rate was 28.8% at a mean 4.3-year follow-up, with a revision rate of 34.8%. On univariate analysis, PJF was associated with a greater age and BMI, worse baseline PROMs, the use of PCOs, and greater postoperative TK and PJA. The use of UIV hooks was protective against PJF. On multivariate analysis (without postoperative measures), a higher risk of PJF was associated with greater BMI and preoperative TK and lower preoperative PJA.

Rod fractures in thoracolumbar fusions to the sacrum/pelvis for adult symptomatic lumbar scoliosis: long-term follow-up of a prospective, multicenter cohort of 160 patients

OBJECTIVE

Previous reports of rod fracture (RF) in adult spinal deformity are limited by heterogeneous cohorts, low follow-up rates, and relatively short follow-up durations. Since the majority of RFs present > 2 years after surgery, true occurrence and revision rates remain unclear. The objectives of this study were to better understand the risk factors for RF and assess its occurrence and revision rates following primary thoracolumbar fusions to the sacrum/pelvis for adult symptomatic lumbar scoliosis (ASLS) in a prospective series with long-term follow-up.

METHODS

Patient records were obtained from the Adult Symptomatic Lumbar Scoliosis-1 (ASLS-1) database, an NIH-sponsored multicenter, prospective study. Inclusion criteria were as follows: patients aged 40-80 years undergoing primary surgeries for ASLS (Cobb angle ≥ 30° and Oswestry Disability Index ≥ 20 or Scoliosis Research Society-22r ≤ 4.0 in pain, function, and/or self-image) with instrumented fusion of ≥ 7 levels that included the sacrum/pelvis. Patients with and without RF were compared to assess risk factors for RF and revision surgery.

RESULTS

Inclusion criteria were met by 160 patients (median age 62 years, IQR 55.7-67.9 years). At a median follow-up of 5.1 years (IQR 3.8-6.6 years), there were 92 RFs in 62 patients (38.8%). The median time to RF was 3.0 years (IQR 1.9-4.54 years), and 73% occurred > 2 years following surgery. Based on Kaplan-Meier analyses, estimated RF rates at 2, 4, 5, and 8 years after surgery were 11%, 24%, 35%, and 49%, respectively. Baseline radiographic, clinical, and demographic characteristics were similar between patients with and without RF. In Cox regression models, greater postoperative pelvic tilt (HR 1.895, 95% CI 1.196-3.002, p = 0.0065) and greater estimated blood loss (HR 1.02, 95% CI 1.005-1.036, p = 0.0088) were associated with increased risk of RF. Thirty-eight patients (61% of all RFs) underwent revision surgery. Bilateral RF was predictive of revision surgery (HR 3.52, 95% CI 1.8-6.9, p = 0.0002), while patients with unilateral nondisplaced RFs were less likely to require revision (HR 0.39, 95% CI 0.18-0.84, p = 0.016).

CONCLUSIONS

This study provides what is to the authors' knowledge the highest-quality data to date on RF rates following ASLS surgery. At a median follow-up of 5.1 years, 38.8% of patients had at least one RF. Estimated RF rates at 2, 4, 5, and 8 years after surgery were 11%, 24%, 35%, and 49%, respectively. Greater estimated blood loss and postoperative pelvic tilt were significant risk factors for RF. These findings emphasize the importance of long-term follow-up to realize the true prevalence and cumulative incidence of RF.

Individual differences in postoperative recovery trajectories for adult symptomatic lumbar scoliosis

OBJECTIVE

The Adult Symptomatic Lumbar Scoliosis-1 (ASLS-1) trial demonstrated the benefit of adult symptomatic lumbar scoliosis (ASLS) surgery. However, the extent to which individuals differ in their postoperative recovery trajectories is unknown. This study's objective was to evaluate variability in and factors moderating recovery trajectories after ASLS surgery.

METHODS

The authors used longitudinal, multilevel models to analyze postoperative recovery trajectories following ASLS surgery. Study outcomes included the Oswestry Disability Index (ODI) score and Scoliosis Research Society-22 (SRS-22) subscore, which were measured every 3 months until 2 years postoperatively. The authors evaluated the influence of preoperative disability level, along with other potential trajectory moderators, including radiographic, comorbidity, pain/function, demographic, and surgical factors. The impact of different parameters was measured using the R2, which represented the amount of variability in ODI/SRS-22 explained by each model. The R2 ranged from 0 (no variability explained) to 1 (100% of variability explained).

RESULTS

Among 178 patients, there was substantial variability in recovery trajectories. Applying the average trajectory to each patient explained only 15% of the variability in ODI and 21% of the variability in SRS-22 subscore. Differences in preoperative disability (ODI/SRS-22) had the strongest influence on recovery trajectories, with patients having moderate disability experiencing the greatest and most rapid improvement after surgery. Reflecting this impact, accounting for the preoperative ODI/SRS-22 level explained an additional 56%-57% of variability in recovery trajectory, while differences in the rate of postoperative change explained another 7%-9%. Among the effect moderators tested, pain/function variables-such as visual analog scale back pain score-had the biggest impact, explaining 21%-25% of variability in trajectories. Radiographic parameters were the least influential, explaining only 3%-6% more variance than models with time alone. The authors identified several significant trajectory moderators in the final model, such as significant adverse events and the number of levels fused.

CONCLUSIONS

ASLS patients have highly variable postoperative recovery trajectories, although most reach steady state at 12 months. Preoperative disability was the most important influence, although other factors, such as number of levels fused, also impacted recovery.

Geometric analysis of pedicle subtraction osteotomy (PSO) for Kyphosis correction: anterior lengthening may occur at the osteotomized body as well as at the discs above and below

OBJECTIVE

To validate the authors kyphosis correction formula for pedicle subtraction osteotomy (PSO) cases. Additionally, to use the formula to evaluate the safety of PSO by determining if there is anterior lengthening.

METHODS

Twenty-two patients with primarily kyphosis corrected by PSO and with clear landmarks on preoperative and postoperative x-rays were selected. Several anatomical lines and angle measurements were utilized as depicted previously in the Vertebral Column Resection formula (see below). Two approximations were calculated: the geometric approximation (G) = (tanG°*2 + 1)*15° and the rough approximation (R) which is about the same amount of actual shortening (x), if parallel length (y) ≥ 40; twice of x, if y < 40. For each patient, the change of segmental kyphosis angle (K°) was measured and compared with G° and R°, and the correlation between each value was analyzed.

RESULTS

The absolute Mean ± SE for K - G and K - R was 2.33° ± 0.34 and 6.09° ± 0.58, respectively. K - G is < 3° (p = 0.03). K - R is < 8° (p = 0.001). In other words, K was close to G and R and thus can be predicted by these approximations. Average posterior shortening, anterior shortening, and kyphosis correction at each level were 20.8 ± 2.0 mm, - 3.64 ± 1.5 mm (which equates to anterior lengthening), and 31.05° ± 2.0, respectively. Anterior lengthening occurred in 13 cases (in 4 cases, both at the body as well as at the disc above and below.) The correlation between posterior and anterior shortening was 0.03 (p = 0.88). There were 3 cage insertion cases: 1 had anterior lengthening, while 2 had anterior shortening even with the cage.

CONCLUSION

This study validated the geometric and rough approximations originally used in PVCR patients, for PSO patients. Additionally, this study found that anterior lengthening may occur in PSOs usually at the discs, but occasionally at the osteotomized body.

The impact of lumbar alignment targets on mechanical complications after adult lumbar scoliosis surgery

PURPOSE

The purpose of this study was to determine the discriminatory ability of age-adjusted alignment offset and the global alignment and proportion (GAP) score parameters to predict postoperative mechanical complications.

METHODS

Surgical patients from the Adult Symptomatic Lumbar Scoliosis cohort were reviewed at 2 year follow up. Age-adjusted alignment offsets and GAP parameters were calculated for each patient. A series of nonlinear logistic regression models were fit, and the odds of mechanical complications were calculated. The discriminatory ability of the GAP score, GAP score parameters, and age-adjusted alignment offsets were determined plotting receiver operative characteristic (ROC) with the C statistic (AUC).

RESULTS

A total of 165 patients were included. A total of 49 mechanical complications occurred in 41 patients (21 proximal junctional kyphosis and 28 pseudoarthrosis). The GAP score had no discriminatory ability in this cohort. Relative lumbar lordosis 15 degrees greater than ideal lumbar lordosis was associated with greater mechanical complications. A lumbar distribution index of 90% was associated with fewer mechanical complications compared to a lumbar distribution index of 65%. Age-adjusted offset alignment targets had no discriminatory ability to predict mechanical complications.

CONCLUSION

Radiographic alignment targets using either age-adjusted alignment target offset or GAP score parameters had minimal ability to predict mechanical complications in isolation. Mechanical complications following adult spinal deformity surgery are complex, and patient factors play a critical role. Clinical trial registeration This study was registered at ClinicalTrials.gov (number NCT00854828) in March 2009.

Evaluation of global alignment and proportion score in an independent database

BACKGROUND CONTEXT

Sagittal spinopelvic alignment has been associated with patient-reported outcome measures and mechanical complication rates. Recently, it was claimed that linear numerical values of pelvic tilt and lumbar lordosis measurements may be misleading for patients that have different magnitudes of pelvic incidence. The use of "relative" measurements embedded in a weighted scoring of Global Alignment and Proportion (GAP) was proposed.

PURPOSE

The purpose was to evaluate the GAP scorein an independent database.

STUDY DESIGN/SETTING

Retrospective Cohort Study PATIENT SAMPLE: Adult spinal deformity patients who underwent ≥7 levels posterior fusion to the pelvis between 2004 and 2014 were included.

OUTCOME MEASURES

Mechanical Complication Rates.

METHODS

Demographic, clinical, surgical and radiographic patient characteristics were recorded. Cochran-Armitage tests were used to compare mechanical complication rates in GAP categories. Uni and multivariable logistic regression analyses were used to obtain crude and adjusted Odds Ratios, of predictor (GAP categories) and the outcome (mechanical complication), and Risk Ratios were calculated. The diagnostic performance of the GAP score was tested using the area under the receiver operating characteristic curve, sensitivity, specificity, positive predictive value, negative predictive value and accuracy in predicting mechanical complications.

RESULTS

A total of 322 patients (285F, 37M) with a mean age of 58.2±9.6 were analyzed. Mean follow-up was 69.7 months (range 24 to 177). Mechanical complications occurred in 52.2% of the patients. Mechanical complication rates in proportioned (GAP-P), moderately (GAP-MD) and severely disproportioned (GAP-SD) patients were 21.8%, 55.1%, and 70.4%, respectively. AUC for the GAP score, at 2 years, was 0.682 (95% CI, 0.624 to 0.741, p<.001). AUC at minimum 5 years follow-up was similar at 0.708, while AUC at minimum 7- and 12-year follow-up were 78.5 and 90.7, respectively. Having a postoperative spinopelvic alignment of GAP-MD and GAP-SD resulted in 2.5 and 3.2 folds of relative risk in incurring a mechanical complication when compared to having a proportioned spinopelvic state, respectively.

CONCLUSIONS

This study reports an association between the GAP Score and mechanical complications in an independent database. Increased association was noted as the years of follow-up increased. Aiming to achieve proportionate GAP Score postoperatively seems to be a viable option as lower GAP scores were associated with lower rates of mechanical complications, and vice versa.

Orthopedic disease burden in adult patients with symptomatic lumbar scoliosis: results from a prospective multicenter study

OBJECTIVE

Although the health impact of adult symptomatic lumbar scoliosis (ASLS) is substantial, these patients often have other orthopedic problems that have not been previously quantified. The objective of this study was to assess disease burden of other orthopedic conditions in patients with ASLS based on a retrospective review of a prospective multicenter cohort.

METHODS

The ASLS-1 study is an NIH-sponsored prospective multicenter study designed to assess operative versus nonoperative treatment for ASLS. Patients were 40-80 years old with ASLS, defined as a lumbar coronal Cobb angle ≥ 30° and Oswestry Disability Index ≥ 20, or Scoliosis Research Society-22 questionnaire score ≤ 4.0 in pain, function, and/or self-image domains. Nonthoracolumbar orthopedic events, defined as fractures and other orthopedic conditions receiving surgical treatment, were assessed from enrollment to the 4-year follow-up.

RESULTS

Two hundred eighty-six patients (mean age 60.3 years, 90% women) were enrolled, with 173 operative and 113 nonoperative patients, and 81% with 4-year follow-up data. At a mean (± SD) follow-up of 3.8 ± 0.9 years, 104 nonthoracolumbar orthopedic events were reported, affecting 69 patients (24.1%). The most common events were arthroplasty (n = 38), fracture (n = 25), joint ligament/cartilage repair (n = 13), and cervical decompression/fusion (n = 7). Based on the final adjusted model, patients with a nonthoracolumbar orthopedic event were older (HR 1.44 per decade, 95% CI 1.07-1.94), more likely to have a history of tobacco use (HR 1.63, 95% CI 1.00-2.66), and had worse baseline leg pain scores (HR 1.10, 95% CI 1.01-1.19).

CONCLUSIONS

Patients with ASLS have high orthopedic disease burden, with almost 25% having a fracture or nonthoracolumbar orthopedic condition requiring surgical treatment during the mean 3.8 years following enrollment. Comparisons with previous studies suggest that the rate of total knee arthroplasty was considerably greater and the rates of total hip arthroplasty were at least as high in the ASLS-1 cohort compared with the similarly aged general US population. These conditions may further impact health-related quality of life and outcomes assessments of both nonoperative and operative treatment approaches in patients with ASLS.

Adolescent Idiopathic Scoliosis Treated by Posterior Spinal Segmental Instrumented Fusion : When Is Fusion to L3 Stable?

Objective

The purpose of this study was to identify risk factors for distal adding on (AO) or distal junctional kyphosis (DJK) in adolescent idiopathic scoliosis (AIS) treated by posterior spinal fusion (PSF) to L3 with a minimum 2-year follow-up.

Methods

AIS patients undergoing PSF to L3 by two senior surgeons from 2000-2010 were analyzed. Distal AO and DJK were deemed poor radiographic results and defined as >3 cm of deviation from L3 to the center sacral vertical line (CSVL), or >10° angle at L3-4 on the posterior anterior- or lateral X-ray at ultimate follow-up. New stable vertebra (SV) and neutral vertebra (NV) scores were defined for this study. The total stability (TS) score was the sum of the SV and NV scores.

Results

Ten of 76 patients (13.1%) were included in the poor radiographic outcome group. The other 66 patients were included in the good radiographic outcome group. Lower Risser grade, more SV-3 (CSVL doesn't touch the lowest instrumented vertebra [LIV]) on standing and side bending films, lesser NV and TS score, rigid L3-4 disc, more rotation and deviation of L3 were identified risk factors for AO or DJK. Age, number of fused vertebrae, curve correction, preoperative coronal/sagittal L3-4 disc angle did not differ significantly between the two groups. Multiple logistic regression results indicated that preoperative Risser grade 0, 1 (odds ratio [OR], 1.8), SV-3 at L3 in standing and side benders (OR, 2.1 and 2.8, respectively), TS score -5, -6 at L3 (OR, 4.4), rigid disc at L3-4 (OR, 3.1), LIV rotation >15° (OR, 2.9), and LIV deviation >2 cm from CSVL (OR, 2.2) were independent predictive factors. Although there was significant improvement of the of Scoliosis Research Society-22 average scores only in the good radiographic outcome group, there was no significant difference in the scores between the groups.

Conclusion

The prevalence of AO or DJK at ultimate follow-up for AIS with LIV at L3 was 13.1%. To prevent AO or DJK following fusion to L3, we recommend that the CSVL touch L3 in both standing and side bending, TS score is -4 or less, the L3/4 disc is flexible, L3 is neutral (<15°) and ≤2 cm from the midline and the patient is ≥ Risser 2.

Operative versus nonoperative treatment for adult symptomatic lumbar scoliosis at 5-year follow-up: durability of outcomes and impact of treatment-related serious adverse events

OBJECTIVE

Although short-term adult symptomatic lumbar scoliosis (ASLS) studies favor operative over nonoperative treatment, longer outcomes are critical for assessment of treatment durability, especially for operative treatment, because the majority of implant failures and nonunions present between 2 and 5 years after surgery. The objectives of this study were to assess the durability of treatment outcomes for operative versus nonoperative treatment of ASLS, to report the rates and types of associated serious adverse events (SAEs), and to determine the potential impact of treatment-related SAEs on outcomes.

METHODS

The ASLS-1 (Adult Symptomatic Lumbar Scoliosis-1) trial is an NIH-sponsored multicenter prospective study to assess operative versus nonoperative ASLS treatment. Patients were 40-80 years of age and had ASLS (Cobb angle ≥ 30° and Oswestry Disability Index [ODI] ≥ 20 or Scoliosis Research Society [SRS]-22 subscore ≤ 4.0 in the Pain, Function, and/or Self-Image domains). Patients receiving operative and nonoperative treatment were compared using as-treated analysis, and the impact of related SAEs was assessed. Primary outcome measures were ODI and SRS-22.

RESULTS

The 286 patients with ASLS (107 with nonoperative treatment, 179 with operative treatment) had 2-year and 5-year follow-up rates of 90% (n = 256) and 74% (n = 211), respectively. At 5 years, compared with patients treated nonoperatively, those who underwent surgery had greater improvement in ODI (mean difference -15.2 [95% CI -18.7 to -11.7]) and SRS-22 subscore (mean difference 0.63 [95% CI 0.48-0.78]) (p < 0.001), with treatment effects (TEs) exceeding the minimum detectable measurement difference (MDMD) for ODI (7) and SRS-22 subscore (0.4). TEs at 5 years remained as favorable as 2-year TEs (ODI -13.9, SRS-22 0.52). For patients in the operative group, the incidence rates of treatment-related SAEs during the first 2 years and 2-5 years after surgery were 22.38 and 8.17 per 100 person-years, respectively. At 5 years, patients in the operative group who had 1 treatment-related SAE still had significantly greater improvement, with TEs (ODI -12.2, SRS-22 0.53; p < 0.001) exceeding the MDMD. Twelve patients who received surgery and who had 2 or more treatment-related SAEs had greater improvement than nonsurgically treated patients based on ODI (TE -8.34, p = 0.017) and SRS-22 (TE 0.32, p = 0.029), but the SRS-22 TE did not exceed the MDMD.

CONCLUSIONS

The significantly greater improvement of operative versus nonoperative treatment for ASLS at 2 years was durably maintained at the 5-year follow-up. Patients in the operative cohort with a treatment-related SAE still had greater improvement than patients in the nonoperative cohort. These findings have important implications for patient counseling and future cost-effectiveness assessments.

The Prevalence of Adding-On or Distal Junctional Kyphosis in Adolescent Idiopathic Scoliosis Treated By Anterior Spinal Fusion to L3 was Significantly Higher Than By Posterior Spinal Fusion to L3

Objective

To compare and identify risk factors for distal adding-on (AO) or distal junctional kyphosis (DJK) in adolescent idiopathic scoliosis (AIS) treated by anterior- (ASF) and posterior spinal fusion (PSF) to L3.

Methods

AIS patients undergoing ASF versus PSF to L3 from 2000–2010 were analyzed. Distal AO and DJK were deemed poor radiographic results. New stable (SV) and neutral vertebra (NV) scores were defined for this study. The total stability (TS) score was the sum of the SV and NV scores.

Results

Twenty of 42 (ASF group: 47.6%) and 8 of 72 patients (PSF group: 11.1%) showed poor radiographic outcome. Fused vertebrae, correction rate of main curve, coronal reduction rate of L3 were significantly higher in PSF group. Multiple logistic regression results indicated that preoperative SV-3 at L3 in standing and side benders (odds ratio [OR], 2.7 and 3.7, respectively), TS score -5, -6 at L3 (OR, 4.9), rigid disc at L3–4 (OR, 3.7), lowest instrumented vertebra (LIV) rotation > 15° (OR, 3.3), LIV deviation > 2 cm from center sacral vertical line (OR, 3.1) and ASF (OR, 13.4; p<0.001) were independent predictive factors. There was significant improvement of the Scoliosis Research Society (SRS)-22 average scores only in PSF group. Furthermore, the ultimate scores of PSF group were significantly superior to ASF group.

Conclusion

The prevalence of AO or DJK at ultimate follow-up for AIS with LIV at L3 was significantly higher in ASF group. Ultimate SRS-22 scores were significantly better in PSF group.

Thoracolumbar Junction Orientation: A Novel Guide for Sagittal Correction and Proximal Junctional Kyphosis Prediction in Adult Spinal Deformity Patients

BACKGROUND

Novel radiographic sagittal parameters of the thoracolumbar junction orientation (TLJO, thoracolumbar slope [TLS] and thoracolumbar tilt [TLT]) have been introduced and correlated with lumbopelvic parameters and thoracic kyphosis.

OBJECTIVE

To determine a predictive model for reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) based on the TLJO.

METHODS

A total of 127 patients who had fusion from sacrum to T10-L2 from 2004 to 2014 were reviewed. TK (T5-T12), PI, SS, PT, LL, and proximal junctional angle (PJA) were measured preoperatively, 6 wk postoperatively, and at final follow-up. TLJO was measured by TLS and TLT. Changes between time points were determined (preop-6 wk = ΔParameterPre6wk and preop-final follow/up = ΔParameterPreFinal). Scoliosis Research Society (SRS) and Oswestry Disability Index (ODI) questionnaires were evaluated at final follow-up. Patients were divided into 2 groups based on the presence of PJK (ΔPJAPreFinal >15°). Independent t-tests and receiver operating characteristic (ROC) curves were used to investigate the significance of differences and cut-off values. Pearson correlations and linear regressions were used to analyze the entire cohort to determine the relationship between the changes in parameters.

RESULTS

Compared to patients without PJK (n = 100), those with PJK (n = 27) had significantly lower SRS scores and significantly greater ΔTKPreFinal, ΔLLPre6wk, and ΔTLSPre6wk. To maintain in the nonPJK group, ROC curves demonstrated a cut-off value of -9.4° for ΔTLSPre6wk. PJK was significantly correlated with ΔTKPreFinal and ΔTLSPre6wk. The linear correlation revealed that ΔTLSPre6wk < -25.3° is the risk factor of PJK > 15°.

CONCLUSION

As change of TLS reflects lumbopelvic realignment and influences reciprocal TK, reducing the change of TLS may be a sagittal realignment guideline to reduce the risk of PJK.

Differences in Functional Treadmill Tests in Patients With Adult Symptomatic Lumbar Scoliosis Treated Operatively and Nonoperatively

STUDY DESIGN

Prospective longitudinal cohort.

OBJECTIVES

The aim of this study was to determine whether functional treadmill testing (FTT) demonstrates differences between patients treated operatively and nonoperatively for adult symptomatic lumbar scoliosis (ASLS).

SUMMARY OF BACKGROUND DATA

ASLS has become increasingly prevalent as the population ages. ASLS can be accompanied by neurogenic claudication, leading to difficulty walking. FTT may provide a functional tool to evaluate patients with ASLS.

METHODS

One hundred and eighty-seven patients who underwent nonoperative (n = 88) or operative treatment (n = 99) of ASLS with complete baseline and 2-year post-treatment FTTs and concurrent patient-reported outcomes were identified. FTT parameters included maximum speed, time to onset of symptoms, distance ambulated, time ambulated, and Back and Leg pain severity before and after testing.

RESULTS

At baseline, patients treated operatively reported worse post-FTT back pain (4.39 vs. 3.45, P = 0.032) than those treated nonoperatively, despite similar ODI, SRS-22 Pain and Activity domain scores. Mean time ambulated (+2.15 vs. -1.20 P = 0.001), pre-FTT back pain (+0.19 vs. -1.60, P < 0.000) and leg pain (+0.25 vs. -0.54, P = 0.024) improved in the operative group but deteriorated in the nonoperative group. On the 2-year follow-up FTT, both groups showed improvement in post-FTT back pain (-0.53 vs. -2.64, P < 0.000) and leg pain (-0.13 vs. -1.54, P = 0.001) severity but the improvement was statistically significantly greater in the operative compared to the nonoperative group.

CONCLUSION

FTT results at baseline were worse in patients treated operatively than those treated non-operatively. FTT may be a useful adjunct to assess treatment outcomes in patients with ASLS and may help surgeons counsel patients regarding expectations 2 years after operative or nonoperative treatment for ASLS. At 2-year follow-up, time ambulated deteriorated in patients treated nonoperatively but improved in patients treated operatively. Although both groups showed improvement in post-FTT Back and Leg pain at 2 years, the improvement was greater in the operative compared to the nonoperative group.

LEVEL OF EVIDENCE

2.

Comprehensive classification system for multirod constructs across three-column osteotomies: a reliability study

OBJECTIVE

In this study, the authors' goal was to determine the intra- and interobserver reliability of a new classification system that allows the description of all possible constructs used across three-column osteotomies (3COs) in terms of rod configuration and density.

METHODS

Thirty-five patients with multirod constructs (MRCs) across a 3CO were classified by two spinal surgery fellows according to the new system, and then were reclassified 2 weeks later. Constructs were classified as follows: the number of rods across the osteotomy site followed by a letter corresponding to the type of rod configuration: "M" is for a main rod configuration, defined as a single rod spanning the osteotomy. "L" is for linked rod configurations, defined as 2 rods directly connected to each other at the osteotomy site. "S" is for satellite rod configurations, which were defined as a short rod independent of the main rod with anchors above and below the 3CO. "A" is for accessory rods, defined as an additional rod across the 3CO attached to main rods but not attached to any anchors across the osteotomy site. "I" is for intercalary rod configurations, defined as a rod connecting 2 separate constructs across the 3CO, without the intercalary rod itself attached to any anchors across the osteotomy site. The intra- and interobserver reliability of this classification system was determined.

RESULTS

A sample estimation for validation assuming two readers and 35 subjects results in a two-sided 95% confidence interval with a width of 0.19 and a kappa value of 0.8 (SD 0.3). The Fleiss kappa coefficient (κ) was used to calculate the degree of agreement between interrater and intraobserver reliability. The interrater kappa coefficient was 0.3, and the intrarater kappa coefficient was 0.63 (good reliability). This scenario represents a high degree of agreement despite a low kappa coefficient. Correct observations by both observers were 34 of 35 and 33 of 35 at both time points. Misclassification was related to difficulty in determining connectors versus anchors.

CONCLUSIONS

MRCs across 3COs have variable rod configurations. Currently, no classification system or agreement on nomenclature exists to define the configuration of rods across 3COs. The authors present a new, comprehensive MRC classification system with good inter- and intraobserver reliability and a high degree of agreement that allows for a standardized description of MRCs across 3COs.

Pedicle Subtraction Osteotomy

Pedicle subtraction osteotomy (PSO) was originally performed in cases of ankylosing spondylitis. This procedure was invented because it was safer than trying to lengthen the anterior column via osteoclasis, which risked vascular injury and death^1-4. PSO involves the removal of the posterior elements and the use of a vertebral body wedge to shorten the spine posteriorly and achieve sagittal-plane correction^5,6. PSO has been used to correct sagittal-plane deformities not only in patients with ankylosing spondylitis but also in those with degenerative conditions or those who have previously undergone surgical procedures resulting in a loss of lumbar lordosis^7,8.

Description

The fixation points are placed with pedicle screws above and below the planned osteotomy level. The posterior elements are decompressed at the level of the osteotomy and at 1 level proximally. In addition to the use of straight and angled curets, a high-speed burr is used to decancellate the vertebral body. Pedicle osteotomes are used to remove the pedicle. Temporary rods are placed. The posterior wall of the body is then impacted into the vertebral body, and the temporary rods are loosened. To close the osteotomy, the bed is extended or the spine is pushed manually, resulting in correction of the lordosis. The temporary rods are tightened. The main rods, independent of the short rods, are used to connect multiple segments several levels above and below the osteotomy site to provide final stabilization.

Alternatives

The alternatives to PSO depend on the surgical history of the patients, as well as the flexibility and alignment of the spine. In a spine with mobile disc spaces, Smith-Petersen osteotomies can be performed posteriorly to shorten the posterior column over multiple segments to gain lordosis. A formal anterior or lateral approach can be performed to release the disc spaces and restore the disc height. A posterior release through the facet joints with segmental compression can achieve desired lumbar lordosis. A vertebral column resection can also be performed to achieve lordosis.

Rationale

PSO is ideal for patients who have undergone multiple spinal fusions and who have a very rigid, flat lumbar spine. A single posterior approach can be used to provide adequate correction of the flat lumbar spine up to 40°. Asymmetric PSO can also be performed to allow for correction in the coronal plane. Recently, PSO has been performed more frequently because of the improved osteotomy instrumentation, exposure to resection techniques, and improved positioning tables that allow correction of the osteotomy.

Effect modifiers for patient-reported outcomes in operatively and nonoperatively treated patients with adult symptomatic lumbar scoliosis: a combined analysis of randomized and observational cohorts

OBJECTIVE

Adult symptomatic lumbar scoliosis (ASLS) is a common and disabling condition. The ASLS-1 was a multicenter, dual-arm study (with randomized and observational cohorts) examining operative and nonoperative care on health-related quality of life in ASLS. An aim of ASLS-1 was to determine patient and radiographic factors that modify the effect of operative treatment for ASLS.

METHODS

Patients 40-80 years old with ASLS were enrolled in randomized and observational cohorts at 9 North American centers. Primary outcomes were the differences in mean change from baseline to 2-year follow-up for the SRS-22 subscore (SRS-SS) and the Oswestry Disability Index (ODI). Analyses were performed using an as-treated approach with combined cohorts. Factors examined were prespecified or determined using regression tree analysis. For each potential effect modifier, subgroups were created using clinically relevant cutoffs or via regression trees. Estimates of within-group and between-group change were compared using generalized linear mixed models. An effect modifier was defined as a treatment effect difference greater than the minimal detectable measurement difference for both SRS-SS (0.4) and ODI (7).

RESULTS

Two hundred eighty-six patients were enrolled and 256 (90%) completed 2-year follow-up; 171 received operative treatment and 115 received nonoperative treatment. Surgery was superior to nonoperative care for all effect subgroups considered, with the exception of those with nearly normal pelvic incidence-lumbar lordosis (PI-LL) match (≤ 11°). Male patients and patients with more (> 11°) PI-LL mismatch at baseline had greater operative treatment effects on both the SRS-SS and ODI compared to nonoperative treatment. No other radiographic subgroups were associated with treatment effects. High BMI, lower socioeconomic status, and poor mental health were not related to worse outcomes.

CONCLUSIONS

Numerous factors previously related to poor outcomes with surgery, such as low mental health, lower socioeconomic status, and high BMI, were not related to outcomes in ASLS in this exploratory analysis. Those patients with higher PI-LL mismatch did improve more with surgery than those with normal alignment. On average, none of the factors considered were associated with a worse outcome with operative treatment versus nonoperative treatment. These findings may guide future prospective analyses of factors related to outcomes in ASLS care.

Comparison of rod fracture rates in long spinal deformity constructs after transforaminal versus anterior lumbar interbody fusions: a single-institution analysis

OBJECTIVE

Pseudarthrosis is a common complication of long-segment fusions after surgery for correction of adult spinal deformity (ASD). Interbody fusions are frequently used at the caudal levels of long-segment spinal deformity constructs as adjuncts for anterior column support. There is a paucity of literature comparing rod fracture rates (proxy for pseudarthrosis) in patients undergoing transforaminal lumbar interbody fusion (TLIF) versus anterior lumbar interbody fusion (ALIF) at the caudal levels of the long spinal deformity construct. In this study the authors sought to compare rod fracture rates in patients undergoing surgery for correction of ASD with TLIF versus ALIF at the caudal levels of long spinal deformity constructs.

METHODS

We reviewed clinical records of patients who underwent surgery for correction of ASD between 2008 and 2014 at a single institution. Data including demographics, comorbidities, and indications for surgery, as well as postoperative variables, were collected for each patient. All patients had a minimum 2-year follow-up. Patients were dichotomized into two groups for comparison on the basis of undergoing a TLIF versus an ALIF procedure at the caudal levels of long spinal deformity constructs. The primary outcome of interest was the rate of rod fractures.

RESULTS

A total of 198 patients (TLIF 133 patients; ALIF 65 patients) underwent a long-segment fusion to the sacrum with iliac fixation. The mean ± standard deviation follow-up period was 62.23 ± 29.26 months. Baseline demographic variables were similar in both patient groups. There were no significant differences between groups in the severity of the baseline sagittal plane deformity (i.e., baseline lumbar-pelvic parameters) or the final deformity correction achieved. Mean total recombinant human bone morphogenetic protein 2 (rhBMP-2) dose for L1-sacrum fusion was significantly higher in the ALIF (100 mg) than in the TLIF (62 mg) group. The overall rod failure rate (cases with rod fracture/total cases) within this case series was 19.19% (38/198); 10.60% (21/198) were unilateral rod fractures and 8.58% (17/198) were bilateral rod fractures. At last clinical follow-up, there were no statistically significant differences in bilateral rod fracture rates between the group of patients who had a TLIF procedure and the group who had an ALIF procedure at the caudal levels of the long spinal deformity constructs (TLIF 10.52% vs ALIF 4.61%, p = 0.11). However, the incidence rate (cases per patient follow-up years) for bilateral rod fractures was significantly higher in the TLIF than in the ALIF cohort (TLIF 2.20% vs ALIF 0.70%, p < 0.0001). The reoperation rate for rod fractures was similar between the patient groups (p = 0.40).

CONCLUSIONS

Although both ALIF and TLIF procedures at the caudal levels of long spinal deformity constructs achieved similar and satisfactory deformity correction, ALIFs were associated with a lower rod fracture incidence rate. There were no differences between groups in the prevalence of rod fracture or revision surgery, however, and both groups had low bilateral rod fracture prevalence and incidence rates. One technique is not clearly superior to the other.

Operative Versus Nonoperative Treatment for Adult Symptomatic Lumbar Scoliosis

BACKGROUND

The effectiveness of operative compared with nonoperative treatment at initial presentation (no prior fusion) for adult lumbar scoliosis has not, to our knowledge, been evaluated in controlled trials. The goals of this study were to evaluate the effects of operative and nonoperative treatment and to assess the benefits of these treatments to help treating physicians determine whether patients are better managed operatively or nonoperatively.

METHODS

Patients with adult symptomatic lumbar scoliosis (aged 40 to 80 years, with a coronal Cobb angle measurement of ≥30° and an Oswestry Disability Index [ODI] score of ≥20 or Scoliosis Research Society [SRS]-22 score of ≤4.0) from 9 North American centers were enrolled in concurrent randomized or observational cohorts to evaluate operative versus nonoperative treatment. The primary outcomes were differences in the mean change from baseline in the SRS-22 subscore and ODI at 2-year follow-up. For the randomized cohort, the initial sample-size calculation estimated that 41 patients per group (82 total) would provide 80% power with alpha equal to 0.05, anticipating 10% loss to follow-up and 20% nonadherence in the nonoperative arm. However, an interim sample-size calculation estimated that 18 patients per group would be sufficient.

RESULTS

Sixty-three patients were enrolled in the randomized cohort: 30 in the operative group and 33 in the nonoperative group. Two hundred and twenty-three patients were enrolled in the observational cohort: 112 in the operative group and 111 in the nonoperative group. The intention-to-treat analysis of the randomized cohort found that, at 2 years of follow-up, outcomes did not differ between the groups. Nonadherence was high in the randomized cohort (64% nonoperative-to-operative crossover). In the as-treated analysis of the randomized cohort, operative treatment was associated with greater improvement at the 2-year follow-up in the SRS-22 subscore (adjusted mean difference, 0.7 [95% confidence interval (CI), 0.5 to 1.0]) and in the ODI (adjusted mean difference, -16 [95% CI, -22 to -10]) (p < 0.001 for both). Surgery was also superior to nonoperative care in the observational cohort at 2 years after treatment on the basis of SRS-22 subscore and ODI outcomes (p < 0.001). In an overall responder analysis, more operative patients achieved improvement meeting or exceeding the minimal clinically important difference (MCID) in the SRS-22 subscore (85.7% versus 38.7%; p < 0.001) and the ODI (77.4% versus 38.3%; p < 0.001). Thirty-four revision surgeries were performed in 24 (14%) of the operative patients.

CONCLUSIONS

On the basis of as-treated and MCID analyses, if a patient with adult symptomatic lumbar scoliosis is satisfied with current spine-related health, nonoperative treatment is advised, with the understanding that improvement is unlikely. If a patient is not satisfied with current spine health and expects improvement, surgery is preferred.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Key Role of Preoperative Recumbent Films in the Treatment of Severe Sagittal Malalignment

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine if severe sagittal malalignment (SM) patients without fixed deformities require a three-column osteotomy (3CO) to achieve favorable clinical and radiographic outcomes.

SUMMARY OF BACKGROUND DATA

3CO performed for severe SM has significantly increased in the last 15 years. Not all severe SM patients require a 3CO.

METHODS

Severe SM patients (sagittal vertical axis [SVA] >10 cm) who underwent deformity correction between 2002 and 2011. Patients with <33% change in their lumbar lordosis (LL) on a preoperative supine radiograph were classified as stiff deformities, whereas those with ≥33% change were categorized as flexible deformities. The clinical/radiographic outcomes were assessed at minimum two years postoperatively.

RESULTS

Seventy patients met the inclusion criteria, 35 patients with flexible and 35 with stiff deformities. Eighteen flexible-deformity patients underwent a 3CO versus 22 stiff-deformity patients. The remaining patients in each group underwent spinal realignment without a 3CO. The flexible-deformity patients not undergoing a 3CO had overall improvement in all sagittal radiographic parameters. Preoperative LL (22°), LL-pelvic incidence (PI) mismatch (43), SVA (17 cm), and pelvic tilt (PT, 34°) improved to 46°, 18, 6 cm, and 26°, respectively, p < .05. Flexible-deformity patients who underwent a 3CO also had overall improvement in all radiographic parameters. Preoperative LL (8.5°), LL-PI mismatch (47), SVA (19 cm), and PT (37°) improved to 39°, 15, 7 cm, and 24°, respectively (p < .05). Stiff-deformity patients who underwent a 3CO had statistically significant improvement in all radiographic parameters. However, stiff-deformity patients who did not undergo a 3CO had suboptimal improvement in all radiographic parameters, except for SVA (14 cm-9 cm, p < .05). Flexible patients who did not undergo a 3CO had statistical improvement in the SRS domains of function and self-mage as well as in their ODI scores (p < .05).

CONCLUSION

Severe SM that is flexible can be corrected without a 3CO without compromising clinical and radiographic outcomes.

LEVEL OF EVIDENCE

Level III.

Optimal Lowest Instrumented Vertebra for Thoracic Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective cohort chart review.

OBJECTIVE

To determine the optimal lowest instrumented vertebra (LIV) following posterior segmental spinal instrumented fusion (PSSIF) of thoracic adolescent idiopathic scoliosis (AIS) with LIV at L2 or above.

SUMMARY OF BACKGROUND DATA

Few studies evaluate the optimal LIV based on rotation or center sacral vertical line (CSVL).

METHODS

A radiographic assessment of 544 thoracic major AIS patients (average age 14.7 years) with minimum 2 years' follow-up (average 4.1 years) after PSSIF was performed. The LIV was divided by CSVL: stable vertebra 1 (SV-1) if the CSVL fell between the medial walls of the LIV pedicles; SV-2 if between stable vertebra 1 and 3; and SV-3 if the CSVL did not touch the LIV. LIV was divided by rotation into: neutral vertebra 0 (NV-0) if the LIV was at or distal to the neutral vertebra; NV-1 if one vertebra proximal to the NV; NV-2 if two vertebrae proximal; and NV-3 if three vertebrae proximal to the NV.

RESULTS

The prevalence of adding-on (AO) or distal junctional kyphosis (DJK) at ultimate follow-up was 13.6%. Patients with AO or DJK had a higher rate of open triradiate cartilage, LIV not touching the CSVL, and more proximal to the NV (p < .05). Risk factors were SV-3 (39% vs. SV-2 14%, SV-1 9%, p < .05), NV-3 (35% vs. NV-2 9%, NV-1 6%, NV-0 12%, p = .000), open triradiate cartilage (43% vs. closed 13%, p < .05), lumbar C modifier (22% vs. B modifier 8%, A modifier 13%, p < .05), and Risser stage 0 (19% vs. 12% Risser 1-5, p < .05).

CONCLUSION

The prevalence of AO or DJK at ultimate follow-up of PSSIF for AIS with LIV at L2 or above was 13.6%. Risk factors included the CSVL outside the LIV, LIV 3 or more proximal to the NV, open triradiate cartilage, lumbar C modifier, and Risser stage 0.

LEVEL OF EVIDENCE

Level IV.

Prevalence and Indications for Unplanned Reoperations Following Index Surgery in the Adult Symptomatic Lumbar Scoliosis NIH-Sponsored Clinical Trial

STUDY DESIGN

Longitudinal cohort.

OBJECTIVE

To report on the prevalence and indications for unplanned reoperations following index surgery in the Adult Symptomatic Lumbar Scoliosis NIH-sponsored Clinical Trial.

SUMMARY OF BACKGROUND DATA

Reoperation following adult spinal deformity surgery exposes the patient to additional surgical risk, increases the cost of care, and decreases the potential cost-effectiveness of the intervention. Accurate data regarding the prevalence and indication for reoperation will facilitate future efforts to minimize risk.

METHODS

A total of 153 patients underwent adult spinal deformity surgery as part of the observational, randomized, or crossover groups and were eligible for two-year follow-up. Reoperations were meticulously tracked as part of the National Institutes of Health (NIH)-mandated serious adverse event (SAE) reporting. The primary indication for reoperation was obtained from the treating surgeon's operative report.

RESULTS

Thirty-two patients had one reoperation, two patients underwent two reoperations, and three patients underwent three reoperations. A total of 45 reoperations were performed in 37 patients. Eleven patients (7%) underwent reoperation within 90 days of the index surgery: two for superficial wound dehiscence, three for radiculopathy with screw removal, and six for acute proximal junctional failure (PJF). Four patients underwent reoperation for PJF more than 90 days from index surgery. Twenty-six patients underwent 28 reoperations for rod fracture/pseudoarthrosis.

CONCLUSION

In a consecutive series of adult spinal deformity surgery patients with meticulous follow-up, 24% of patients required an unplanned reoperation. The most common indication for reoperation was rod fracture/pseudoarthrosis, which occurred from 9 months to 3.7 years following the index surgery and accounted for 62% (28/45) of the reoperations. The second most common indication for reoperation was PJF, which occurred from 1 month to 1.6 years following index surgery and accounted for 22% (10/45) of the reoperations. As these complications will likely increase with longer follow-up, efforts to lower the rates of these complications are warranted.

LEVEL OF EVIDENCE

Level II.

Correlation of 2-year SRS-22r and ODI patient-reported outcomes with 5-year patient-reported outcomes after complex spinal fusion: a 5-year single-institution study of 118 patients

OBJECTIVE

Patient-reported outcomes (PROs) are often measured up to 2 years after surgery; however, prospective collection of longitudinal outcomes for 5 years postoperatively can be challenging due to lack of patient follow-up. The aim of this study was to determine whether PROs collected at 2-year follow-up accurately predict long-term PROs 5 years after complex spinal fusion (≥ 5 levels).

METHODS

This was an ambispective study of 118 adult patients (≥ 18 years old) undergoing ≥ 5-level spinal arthrodesis to the sacrum with iliac fixation from January 2002 to December 2011. Patient demographics and radiographic parameters as well as intraoperative variables were collected. PRO instruments (Scoliosis Research Society [SRS]-22r function, self-image, mental health, pain, and Oswestry Disability Index [ODI]) were completed before surgery then at 2 and 5 years after surgery. Primary outcome investigated in this study was the correlation between SRS-22r domains and ODI collected at 2- and 5-year follow-up.

RESULTS

Of the 118 patients, 111 patients had baseline PROs, 105 patients had 2-year follow-up data, and 91 patients had 5-year follow-up PRO data with 72% undergoing revision surgery. The average pre- and postoperative major coronal curve Cobb angles for the cohort were 32.1° ± 23.7° and 19.8° ± 19.3°, respectively. There was a strong correlation between 2- and 5-year ODI (r2 = 0.80, p < 0.001) and between 2- and 5-year SRS-22r domains, including function (r2 = 0.79, p < 0.001), self-image (r2 = 0.82, p < 0.001), mental health (r2 = 0.77, p < 0.001), and pain (r2 = 0.79, p < 0.001). Of the PROs, ODI showed the greatest absolute change from baseline to 2- and 5-year follow-up (2-year Δ 17.6 ± 15.9; 5-year Δ 16.5 ± 19.9) followed by SRS-22r self-image (2-year Δ 1.4 ± 0.96; 5-year Δ 1.3 ± 1.0), pain (2-year Δ 0.94 ± 0.97; 5-year Δ 0.80 ± 1.0), function (2-year Δ 0.60 ± 0.62; 5-year Δ 0.49 ± 0.79), and mental health (2-year Δ 0.49 ± 0.77; 5-year Δ 0.38 ± 0.84).

CONCLUSIONS

Patient-reported outcomes collected at 2-year follow-up may accurately predict long-term PROs (5-year follow-up).

Rod fracture in adult spinal deformity surgery fused to the sacrum: prevalence, risk factors, and impact on health-related quality of life in 526 patients

BACKGROUND CONTEXT

Risk factors associated with rod fracture (RF) following adult spinal deformity (ASD) surgery fused to the sacrum remain debatable, and the impact of RF on patient-reported outcomes (PROs) after ASD surgery has not been investigated.

PURPOSE

We aimed to evaluate the prevalence of and risk factors for RF and determine PROs changes associated with RF after ASD surgery fused to the sacrum.

STUDY DESIGN/SETTING

A retrospective single-center cohort study was performed.

PATIENT SAMPLE

Patients undergoing long-construct posterior spinal fusions to the sacrum performed at a single institution by two senior spine surgeons from 2004 to 2014 were included.

OUTCOME MEASURES

Patient demographics, radiographic parameters, and surgical factors were assessed for risk factors associated with RF. Oswestry Disability Index (ODI) and Scoliosis Research Society-30 (SRS-30) scores were assessed at baseline, 1 year postoperatively, and latest follow-up.

METHODS

Inclusion criteria were ASD patients age >18 who had ≥5 vertebrae instrumented and fused posteriorly to the sacrum and either development of RF or no development of RF with minimum 2-year follow-up. Patient characteristics, operative data, radiographic parameters, and PROs were analyzed at baseline and follow-up. Separate Cox proportional hazard models based on rod material and diameter were used to determine factors associated with RF.

RESULTS

Five hundred twenty-six patients (80%) were available for analysis. RF occurred in 97 (18.4%) patients (unilateral RF n=61 [63%]; bilateral RF n=36 [37%]). Risk factors for fracture of 5.5 mm cobalt chromium (CC) instrumentation (CC 5.5 model) included preoperative sagittal vertical axis (hazard ratio [HR] 1.07, 95% confidence interval [95% CI] 1.02-1.14 per 1-cm increase), preoperative thoracolumbar kyphosis (HR 1.02, 95% CI 1.01-1.04 per 1-degree increase), and number of levels fused for patients who received rhBMP-2 <12 mg per level fused (HR 1.48, 95% CI 1.20-1.82 per 1-level increase). Implants that were 5.5-mm CC constructs were at a higher risk for fracture than 6.35-mm stainless steel (SS) constructs (HR 8.49, 95% CI 4.26-16.89). The RF group had less overall improvement in SRS Satisfaction (0.93 vs. 1.32; p=.007) and SRS Self-image domain scores (0.72 vs. 1.02; p=.01). The bilateral RF group had less overall improvement in ODI (8.1 vs. 15.8; p=.02), SRS Subscore (0.51 vs. 0.85; p=.03), and SRS Pain domain scores (0.48 vs. 0.95; p=.02) compared with the non-RF group at final follow-up.

CONCLUSIONS

The prevalence of all RF after index procedures was 18.4%, 37% for bilateral RF. Greater preoperative sagittal vertical axis, greater preoperative thoracolumbar kyphosis, increased number of vertebrae fused for patients who received rhBMP-2 <12 mg per level fused, and CC 5.5-mm rod were associated with RF. Less improvement in patient satisfaction and self-image was noted in the RF group. Furthermore, bilateral RF significantly affected PROs as measured by ODI and SRS Subscore at final follow-up.

Serious Adverse Events Significantly Reduce Patient-Reported Outcomes at 2-Year Follow-up: Nonoperative, Multicenter, Prospective NIH Study of 105 Patients

STUDY DESIGN

This is an analysis of a prospective 2-year study on nonoperative patients enrolled in the Adult Symptomatic Lumbar Scoliosis (ASLS) National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) trial.

OBJECTIVE

The purpose was to evaluate the impact of serious adverse events (SAEs) on patient-reported outcomes (PROs) in nonoperative management of ASLS as measured by Scoliosis Research Society-22 (SRS-22), Oswestry Disability Index (ODI), and Short Form-12 (SF-12) at 2-year follow-up.

SUMMARY OF BACKGROUND DATA

Little is known about PROs in the nonoperative management of ASLS or the prevalence and impact of SAEs on PROs.

METHODS

The ASLS trial dataset was analyzed to identify adult lumbar scoliosis patients electively choosing or randomly assigned to nonoperative treatment with minimum 2-year follow-up. Patient data were collected prospectively from 2010 to 2015 as part of NIAMS R01-AR055176-01A2 "A Multi-Centered Prospective Study of Quality of Life in Adult Scoliosis." SAEs were defined as life-threatening medical events, new significant or permanent disability, new or prolonged hospitalization, or death.

RESULTS

One hundred five nonoperative patients were studied to 2-year follow-up. Twenty-seven patients (25.7%) had 42 SAEs; 15 (14.3%) had a SAE during the first year. The SAE group had higher body mass index (29.4 vs. 25.2; P = 0.008) and reported worse SRS-22 Function scores than the non-SAE group at baseline (3.3 vs. 3.6; P = 0.024). At 2-year follow-up, SAE patients experienced less improvement (change) in SRS-22 Self-Image (-0.07 vs. 0.26; P = 0.018) and Mental Health domains (-0.19 vs. 0.25; P = 0.002) than non-SAE patients and had lower SRS-22 Function, Self-Image, Subscore, and SF-12 Mental and Physical component scores (MCS/PCS). Fewer SAE patients reached minimal clinically important difference (MCID) threshold in SRS-22 Mental Health (14.8% vs. 43.6%; P = 0.01).

CONCLUSION

A high percentage (25.7%) of ASLS patients managed nonoperatively experienced SAEs. Those patients who sustained a SAE had less improvement in reported outcomes.

LEVEL OF EVIDENCE

2.

Decompression in Adult Lumbar Deformity Surgery Is Associated With Increased Perioperative Complications but Favorable Long-Term Outcomes

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To analyze the impact of performing a formal decompression in patients with adult lumbar scoliosis with symptomatic spinal stenosis on perioperative complications and long-term outcomes.

METHODS

Adult patients undergoing at least 5 levels of fusion to the sacrum with iliac fixation from 2002 to 2008 who had a minimum 5-year follow-up at one institution were studied. Patients who had 3-column osteotomy were excluded from the study. Perioperative complications and clinical outcomes (Scoliosis Research Society [SRS], Oswestry Disability Index [ODI], and Numerical Rating Scale [NRS] back/leg pain) were analyzed. Patients who underwent formal laminectomy/decompressions were compared with those who did not. Differences between the 2 groups were analyzed using Student's t test.

RESULTS

A total of 147 patients were included in the study (Decompression: n = 55 [37%], No decompression: n = 92 [63%]). Average fusion levels for the decompression and no decompression groups were 11 and 12 levels, respectively (P = .26). Mean improvements in SRS domains for decompression versus no decompression patients, respectively, were pain (1.1 vs 0.9, P = .3), function (0.7 vs 0.5, P = .09), self-image (1.1 vs 1.1, P = .9), and mental health (0.5 vs 0.4, P = .5). Furthermore, additional mean improvements were ODI (21 vs 21, P = .14), NRS-Back pain (3.0 vs 1.3, P = .16), and NRS-Leg pain (3.9 vs 0.5, P = .002). Complication rates between the decompression group and no decompression group differed in incidental durotomies (18.2% vs 0%) and cardiac-related (9.1% vs 1.1%).

CONCLUSIONS

Performing a formal decompression in adult lumbar scoliosis with symptomatic spinal stenosis is associated with increased perioperative complications but favorable long-term clinical outcomes.

Health-Related Quality of Life Scores Underestimate the Impact of Major Complications in Lumbar Degenerative Scoliosis Surgery

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To examine Charlson Comorbidity Index (CCMI) as a marker for deterioration in health status not reflected in standard Health Related Quality of Life (HRQOL) measures.

SUMMARY OF BACKGROUND DATA

HRQOL has become a primary metric for assessing outcomes following spinal deformity surgery. However, studies have reported limited impact of complications on postoperative HRQOL outcomes.

METHODS

We examined serial CCMI, complications, and HRQOL outcomes for 138 adult lumbar deformity patients treated surgically with a minimum two-year follow-up that included 126 females (91%) with a mean age of 59.8 years (range, 40.2-78.5). Patients with no, minor, or major complications were compared at baseline and at one and two years postoperation.

RESULTS

Minor complications were observed in 26 patients (19%) and major complications in 15 (11%). Major complications included motor deficit (7), deep vein thrombosis (4), and respiratory failure (3). There was no difference in preoperative SF-36 Physical Component Summary or Scoliosis Research Society-22R (SRS-22R) scores among the groups at baseline. Preoperative CCMI was lowest in the No Complication group (3.52 ± 1.70) followed by the Major (4.00 ± 1.13) and Minor Complication groups (4.15 ± 1.71, p = .165). At one year, there was a significantly greater CCMI deterioration in the Major Complication group (0.80 ± 1.01) compared to both the Minor (0.08 ± 0.27) and No Complication groups (0.27 ± 0.47, p < .001). There was no significant difference in SF-36 Physical Component Summary or SRS-22R scores among the three groups. Similar findings were observed at two years.

CONCLUSIONS

Despite similar one- and two-year HRQOL improvement, patients with major complications had greater deterioration in CCMI. As CCMI is predictive of medical and surgical risk, patients who sustained a major complication now carry a greater likelihood of adverse outcomes with future interventions, including any subsequent spinal surgery. Although this increased risk may not alter the patient's perception of his or her current health status, it may be important, and should be recognized as part of the shared decision-making process.

LEVEL OF EVIDENCE

Level II, high-quality prognostic study.

SRS-22R Minimum Clinically Important Difference and Substantial Clinical Benefit After Adult Lumbar Scoliosis Surgery

STUDY DESIGN

Longitudinal cohort.

OBJECTIVES

To determine if the minimum clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds for the Scoliosis Research Society-22R (SRS22R) domains in patients with degenerative lumbar scoliosis are similar to those in patients with adult spinal deformity (ASD) with fusions extending into the thoracic spine.

SUMMARY OF BACKGROUND DATA

The MCID and SCB thresholds for the SRS22R domains in patients with ASD and adolescent idiopathic scoliosis have been reported.

METHODS

Patients enrolled in the NIH-sponsored Adult Symptomatic Lumbar Scoliosis (ASLS) trial who underwent surgery and completed the SRS22R preoperative and the SRS30 one-year postoperative were identified. One-year postoperative answers to the last eight questions of the SRS30 were used as anchors to determine the MCID and SCB for the Pain, Appearance, and Activity domains, and the Subscore and Total score using receiver operating characteristic (ROC) curve analysis.

RESULTS

The sample population consisted of 147 patients. A total of 132 (89%) were females with a mean age of 59.4 years. There was a statistically significant improvement in all SRS22R scores from preoperative to one-year postoperative. There was also a statistically significant difference in domain scores among the different responses to the anchors. According to the ROC analysis, MCID was 1.17 for Appearance, 0.40 for Activity, 0.60 for Pain, 0.53 for Subscore, and 0.77 for Total; and SCB was 1.67 for Appearance, 0.60 for Activity, 0.62 for Subscore, and 1.11 for Total score. These are similar to previous reports of MCID and SCB thresholds for ASD patients who underwent fusion to the thoracic spine.

CONCLUSION

The MCID and SCB thresholds for the SRS22R domains in patients with adult symptomatic lumbar scoliosis are very similar to the threshold values previously reported for adult deformity patients.

LEVEL OF EVIDENCE

Level II.

Health-related quality of life outcomes in complex adult spinal deformity surgery

OBJECTIVE Significant health-related quality of life (HRQOL) benefits have been observed for patients undergoing primary and revision adult spinal deformity (ASD) surgery. The purpose of this study was to report changes in HRQOL measures in a consecutive series of patients undergoing complex spinal reconstructive surgery, using Scoli-RISK-1 (SR-1) inclusion criteria. METHODS This was a single-center, retrospective cohort study. The SR-1 inclusion criteria were used to define patients with complex ASD treated between June 1, 2009, and June 1, 2011. Standard preoperative and perioperative data were collected, including the Scoliosis Research Society (SRS)-22r instrument. The HRQOL changes were evaluated at a minimum 2-year follow-up. Standardized forms were used to collect surgery-related complications data for all patients. Complications were defined as minor, transient major, or permanent major. Patients who achieved a minimum 2-year follow-up were included in the analysis. RESULTS Eighty-four patients meeting SR-1 criteria were identified. Baseline demographic and surgical data were available for 74/84 (88%) patients. Forty-seven of 74 (64%) patients met the additional HRQOL criteria with a minimum 2-year follow-up (mean follow-up 3.4 years, range 2-6.5 years). Twenty-one percent of patients underwent posterior fusion only, 40% of patients had a posterior column osteotomy, and 38% had a 3-column osteotomy. Seventy-five percent of patients underwent a revision procedure. Significant improvements were observed in all SRS-22r domains: Pain: +0.8 (p < 0.001); Self-Image: +1.4 (p < 0.001); Function: +0.46 (p < 0.001); Satisfaction: +1.6 (p < 0.001); and Mental Health: +0.28 (p = 0.04). With the exception of Mental Health, more than 50% of patients achieved a minimum clinically important difference (MCID) in SRS-22r domain scores (Mental Health: 20/47, 42.6%). A total of 65 complications occurred in 31 patients. This includes 29.8% (14/47) of patients who suffered a major complication and 17% (8/47) who suffered a postoperative neurological deficit, most commonly at the root level (10.6%, 5/47). Of the 8 patients who suffered a neurological deficit, 1 (13%) was able to achieve MCID in the SRS Function domain. CONCLUSIONS The majority of patients experienced clinically relevant improvement in SRS-22r HRQOL scores after complex ASD surgery. The greatest improvements were seen in the SRS Pain and SRS Self-Image domains. Although 30% of patients suffered a major or permanent complication, benefits from surgery were still attained. Patients sustaining a neurological deficit or major complication were unlikely to achieve HRQOL improvements meeting or exceeding MCID for the SRS Function domain.

Factor analysis of the SRS-22 outcome assessment instrument in patients with adult spinal deformity

PURPOSE

Designed for patients with adolescent idiopathic scoliosis, the SRS-22 is now widely used as an outcome instrument in patients with adult spinal deformity (ASD). No studies have confirmed the four-factor structure (pain, function, self-image, mental health) of the SRS-22 in ASD and under different contexts. Factorial invariance of an instrument over time and in different languages is essential to allow for precise interpretations of treatment success and comparisons across studies. This study sought to evaluate the invariance of the SRS-22 structure across different languages and sub-groups of ASD patients.

METHODS

Confirmatory factor analysis was performed on the 20 non-management items of the SRS-22 with data from 245 American English-, 428 Spanish-, 229 Turkish-, 95 French-, and 195 German-speaking patients. Item loading invariance was compared across languages, age groups, etiologies, treatment groups, and assessment times. A separate sample of SRS-22 data from 772 American surgical patients with ASD was used for cross-validation.

RESULTS

The factor structure fitted significantly better to the proposed four-factor solution than to a unifactorial solution. However, items 14 (personal relationships), 15 (financial difficulties), and 17 (days off work) consistently showed weak item loading within their factors across all language versions and in both baseline and follow-up datasets. A trimmed SRS (16 non-management items) that used the four least problematic items in each of the four domains yielded better-fitting models across all languages, but equivalence was still not reached. With this shorter version there was equivalence of item loading with respect to treatment (surgery vs conservative), time of assessment (baseline vs 12 months follow-up), and etiology (degenerative vs idiopathic), but not age (< vs ≥50 years). All findings were confirmed in the cross-validation sample.

CONCLUSION

We recommend removal of the worst-fitting items from each of the four domains of the SRS-instrument (items 3, 14, 15, 17), together with adaptation and standardization of other items across language versions, to provide an improved version of the instrument with just 16 non-management items.

Failure of Intraoperative Monitoring to Detect Postoperative Neurologic Deficits: A 25-year Experience in 12,375 Spinal Surgeries

STUDY DESIGN

Retrospective.

OBJECTIVE

The purpose was to categorize and evaluate intraoperative monitoring (IOM) failure to detect neurologic deficits occurring during spinal surgery.

SUMMARY OF BACKGROUND DATA

The efficacy of spinal cord/nerve root monitoring regarding undetected neurologic deficits is examined in a large, single institution series involving all levels of the spinal column and all spinal surgical procedures.

METHODS

Multimodality IOM included somatosensory-evoked potentials (SSEPs), descending neurogenic-evoked potentials (DNEPs), transcranial motor-evoked potentials (MEPs), dermatomal somatosensory-evoked potentials (DSEPs), and spontaneous and triggered electromyography (spEMG, trgEMG). We reviewed 12,375 patients who underwent surgery for spinal pathology from 1985 to 2010. There were 7178 females (59.3%) and 5197 males (40.7%); 9633 (77.8%) primary surgeries and 2742 (22.2%) revisions. Procedures by spinal level were cervical 29.7% (3671), thoracic/thoracolumbar 45.4% (5624), and lumbosacral 24.9% (3080). Age at surgery was > 18 years - 72.7% (8993) and < 18 years - 27.3% (3382).

RESULTS

Forty-five of the 12,375 patients (0.36%) had false negative outcomes. False negative results by modality were as follows: spEMG (n = 22, 48.8%), trgEMG (n = 8, 17.7%), DSEP (n = 4, 8.8%), DNEP (n = 4, 8.8%), SSEP (n = 3, 6.6%), DSEP/spEMG (n = 3, 6.6%), and trgEMG/spEMG (n = 1, 2.2%). Thirty-seven patients had immediate postoperative deficits unidentified by IOM; 30 patients (81%) involved nerve root monitoring, four patients had spinal cord deficits, and three patients had peripheral sensory deficits. Eight patients had permanent neurologic deficits, six (0.048%) were nerve root and two (0.016%) were spinal cord in nature.

CONCLUSION

Despite correct application and usage, IOM data failed to identify 45 (0.36%) patients with false negative outcomes out of 12,375 surgical patients. Eight patients (0.064%) of these 45 patients had permanent neurologic deficits, six patients had nerve root deficits in nature and two patients had spinal cord deficits. Although admittedly small, this represents the risk of undetected neurologic deficits even when properly using IOM. Deficits are at a higher risk to remain unresolved when not detected by IOM.

LEVEL OF EVIDENCE

4.

Factors associated with long-term patient-reported outcomes after three-column osteotomies

BACKGROUND CONTEXT

Studies have demonstrated sustained improvements in patient-reported outcomes (PROs) after three-column osteotomies (three-COs), but no study has evaluated what factors impact long-term outcomes.

PURPOSE

The aim was to investigate factors associated with PROs in patients who underwent three-CO at minimum 5 years postoperatively.

STUDY DESIGN/SAMPLE

This was a retrospective review of prospective database.

PATIENT SAMPLE

All patients who had a three-CO at a single institution and completed clinical evaluations after at least 5 years postoperative were included.

OUTCOME MEASURES

Oswestry Disability Index (ODI), Scoliosis Research Society (SRS) scores, and radiographic parameters were assessed at baseline and a minimum 5 years postoperatively.

METHODS

Analysis of 120 patients who underwent three-CO (96-pedicle subtraction osteotomy/24-vertebral column resection) was performed. The mean age was 48 years (range 8-79), and clinical follow-up was 7 years (range 5-14). Separate multivariable linear regression analyses were performed to determine factors associated with ODI, SRS average, and SRS satisfaction while controlling for time since surgery and baseline outcome scores.

RESULTS

Average PROs were significantly improved from baseline at a minimum 5-year follow-up (ODI: 48-28, p<.01; SRS: 2.8-3.5, p<.01). The average SRS satisfaction score was 4.0. Average sagittal alignment (C7 plumb) improved 74 mm, with 81% of patients' alignment less than 95 mm. Major surgical complications occurred in 32 patients (27%) with major reoperations in 30 patients (25%). Multivariable regression analysis found that prior surgery and major reoperations were risk factors for worse ODI scores. A diagnosis of adult idiopathic scoliosis and final sagittal alignment less than 95 mm were associated with improved SRS scores. Improvement in major coronal Cobb and final pelvic tilt less than 30° were associated with increased SRS satisfaction.

CONCLUSIONS

With a minimum 5-year follow-up, PROs in patients undergoing three-CO were associated with improvements in radiographic alignment but negatively affected by prior surgery and complications necessitating revision surgery.

Genetic Risk for Aortic Aneurysm in Adolescent Idiopathic Scoliosis

BACKGROUND

Scoliosis is a feature of several genetic disorders that are also associated with aortic aneurysm, including Marfan syndrome, Loeys-Dietz syndrome, and type-IV Ehlers-Danlos syndrome. Life-threatening complications of aortic aneurysm can be decreased through early diagnosis. Genetic screening for mutations in populations at risk, such as patients with adolescent idiopathic scoliosis, may improve recognition of these disorders.

METHODS

The coding regions of five clinically actionable genes associated with scoliosis (COL3A1, FBN1, TGFBR1, TGFBR2, and SMAD3) and aortic aneurysm were sequenced in 343 adolescent idiopathic scoliosis cases. Gene variants that had minor allele frequencies of <0.0001 or were present in human disease mutation databases were identified. Variants were classified as pathogenic, likely pathogenic, or variants of unknown significance.

RESULTS

Pathogenic or likely pathogenic mutations were identified in 0.9% (three) of 343 adolescent idiopathic scoliosis cases. Two patients had pathogenic SMAD3 nonsense mutations consistent with type-III Loeys-Dietz syndrome and one patient had a pathogenic FBN1 mutation with subsequent confirmation of Marfan syndrome. Variants of unknown significance in COL3A1 and FBN1 were identified in 5.0% (seventeen) of 343 adolescent idiopathic scoliosis cases. Six FBN1 variants were previously reported in patients with Marfan syndrome, yet were considered variants of unknown significance based on the level of evidence. Variants of unknown significance occurred most frequently in FBN1 and were associated with greater curve severity, systemic features of Marfan syndrome, and joint hypermobility.

CONCLUSIONS

Clinically actionable pathogenic mutations in genes associated with adolescent idiopathic scoliosis and aortic aneurysm are rare in patients with adolescent idiopathic scoliosis who are not suspected of having these disorders, although variants of unknown significance are relatively common.

CLINICAL RELEVANCE

Routine genetic screening of all patients with adolescent idiopathic scoliosis for mutations in clinically actionable aortic aneurysm disease genes is not recommended on the basis of the high frequency of variants of unknown significance. Clinical evaluation and family history should heighten indications for genetic referral and testing.

Comparison of Anteroposterior to Posterior-Only Correction of Scheuermann's Kyphosis: A Matched-Pair Radiographic Analysis of 92 Patients

STUDY DESIGN

Retrospective radiographic benchmark study.

OBJECTIVE

To evaluate the amount of instrumented correction obtained from a combined anterior/posterior (A/P) versus posterior-only (post-only) approach for Scheuermann's kyphosis.

SUMMARY OF BACKGROUND DATA

An A/P approach was thought to optimize correction; however, instrumentation advances using pedicle screws allow treatment through an all-posterior approach.

METHODS

A total of 166 Scheuermann's kyphosis patients were treated between 2 centers: 90 by combined A/P approach at 1 center and 76 by post-only at the second center. From the 166 patients, a matched cohort of 92 (46 from each) was established according to preoperative sagittal (±10°) and hyperextension (HE) Cobb (±10°) measurements and matched for age and gender.

RESULTS

In the matched-pair group, average preoperative sagittal Cobb angles were 75.9° for the A/P group versus 78.8° for the post-only group (p = .2). The HE Cobb angles were similar (52.4° vs. 51.1°; p = .6). They showed similar corrections (33.7° vs. 30.6°; p = .3) and postoperative Cobb measurements (43.4° vs. 47.1°; p = .2) as well. The number of fusion levels was 9 in the A/P group and 12 in the post-only group; the difference yielded significance (p = .02).

CONCLUSIONS

The A/P and post-only approaches averaged similar degrees of correction. The A/P patients were likely to correct more than their preoperative HE sagittal Cobb measurement, whereas the post-only group corrected close to their preoperative HE measurement. The number of fusion levels was larger with the post-only group.

Management of complications following radiofrequency ablation of a pedicle osteoid osteoma

Radiofrequency ablation (RFA) has become an accepted first-line treatment for osteoid osteomas. Ablation of spinal osteoid osteomas has presented a particular challenge because of their proximity to delicate neural structures. Although many case series have reported multiple successfully treated spinal osteoid osteomas, there are no reports of thermal injury or insufficiency fracture associated with RFA of spinal osteoid osteomas. We report the management of complications that result from treating a spinal osteoid osteoma within a pedicle.

Proximal junctional kyphosis in primary adult deformity surgery: evaluation of 20 degrees as a critical angle

BACKGROUND

: Multiple studies have reported on the prevalence of proximal junctional kyphosis (PJK) following spinal deformity surgery; however, none have demonstrated its significance with respect to functional outcome scores or revision surgery.

OBJECTIVE

: To evaluate if 20° is a possible critical PJK angle in primary adult scoliosis surgery patients as a threshold for worse patient-reported outcomes.

METHODS

: Clinical and radiographic data of 90 consecutive primary surgical patients at a single institution (2002-2007) with adult idiopathic/degenerative scoliosis and 2-year minimum follow-up were analyzed. Assessment included radiographic measurements, but most notably sagittal Cobb angle of the proximal junctional angle at preoperation, between 1 and 2 months, 2 years, and ultimate follow-up.

RESULTS

: Prevalence of PJK ≥20° at 3.5 years was 27.8% (n = 25). Those with PJK ≥20° at ultimate follow-up were older (mean 56 vs 46 years), had lower number of levels fused (median 8 vs 11), and were proximally fused to the lower thoracic spine more often than upper thoracic spine (all P < .001). PJK ≥20° was associated with significantly higher body mass index and fusion to the sacrum with iliac screws (P < .016, P < .029, respectively). Scoliosis Research Society outcome score changes were lower for PJK patients, but not significantly different from those in the non-PJK group.

CONCLUSION

: PJK ≥20° in primary adult idiopathic/degenerative scoliosis does not lead to revision surgery for PJK, but is univariately associated with older age, shorter constructs starting in the lower thoracic spine, obesity, and fusion to the sacrum. The negative results, supported by Scoliosis Research Society outcome data, provide important guidance on the postoperative management of such PJK patients.

ABBREVIATIONS

: BMI, body mass indexLIV, lowest instrumented vertebraeODI, Oswestry Disability IndexPJ, proximal junctionalPJK, proximal junctional kyphosisSRS, Scoliosis Research SocietyUIV, upper instrumented vertebra.

High-dose rhBMP-2 for adults: major and minor complications: a study of 502 spine cases

BACKGROUND

Use of recombinant human bone morphogenetic protein-2 (rhBMP-2) has increased considerably since its introduction in 2002. The complications associated with high-dose rhBMP-2 (≥ 40 mg) are unknown. The purpose of our study was to determine outcomes and medical and surgical complications associated with high-dose rhBMP-2 at short-term and long-term follow-up evaluations.

METHODS

Five hundred and two consecutive adult patients who had received high-dose rhBMP-2 as a part of spinal surgery from 2002 to 2009 at one institution were enrolled. Data were entered prospectively and studied and analyzed retrospectively. Surgical procedures in the thoracic and lumbar spine were included. Major and minor complications were documented intraoperatively, perioperatively, and at the latest follow-up examination. Complications potentially associated with rhBMP-2 use were evaluated for correlation with rhBMP-2 dose. Scoliosis Research Society (SRS) and Oswestry Disability Index (ODI) outcome measures were obtained before and after surgery.

RESULTS

On average, 115 mg (range, 40 to 351 mg) of rhBMP-2 was used. The average age of the patients (410 women and ninety-two men) at the time of the index procedure was 52.4 years (range, eighteen to eighty years). There were 265 primary and 237 revision procedures, and 261 patients had interbody fusion. An average of 11.5 vertebrae were instrumented. The average duration of follow-up was forty-two months (range, fourteen to ninety-two months). The diagnoses included idiopathic scoliosis (41%), degenerative scoliosis (31%), fixed sagittal imbalance (18%), and other diagnoses (10%). The rate of intraoperative complications was 8.2%. The rate of perioperative major surgical complications was 11.6%. The rate of perioperative major medical complications was 11.6%. Minor medical complications occurred in 18.9% of the cases, and minor surgical complications occurred in 2.6%. Logistic regression analysis and Pearson correlation did not identify a significant correlation between rhBMP-2 dosage and radiculopathy (r = -0.006), seroma (r = -0.003), or cancer (r = -0.05). Significant improvements in the ODI score (from a mean of 41 points to a mean of 26 points; p < 0.001) and the SRS total score (from a mean of 3.0 points to a mean of 3.7 points; p < 0.001) were noted at the latest follow-up evaluation.

CONCLUSIONS

This is the largest study of which we are aware that examines complications associated with high-dose rhBMP-2. Major surgical complications occurred in 11.6% of patients, and 11.6% experienced major medical complications. There was a cancer prevalence of 3.4%, but no correlation between increasing rhBMP-2 dosage and cancer, radiculopathy (seen in 1% of the patients), or seroma (seen in 0.6%) was found.

Weight Change and Clinical Outcomes Following Adult Spinal Deformity Surgery in Overweight and Obese Patients

STUDY DESIGN

Retrospective comparative study.

SUMMARY OF BACKGROUND DATA

The effect of spine surgery on postoperative weight loss or weight gain in overweight and obese spinal deformity patients is unknown.

OBJECTIVE

To evaluate the postoperative outcomes and weight changes in adult patients undergoing spinal deformity surgery.

MATERIALS AND METHODS

A total of 104 adult patients undergoing primary spinal deformity surgery were enrolled. All patients had a minimum 2-year follow-up (average, 50.1 months). Preoperative and latest follow-up, body mass index (BMI), Oswestry Disability Index, Scoliosis Research Society (SRS)-22 self-image and SRS outcomes scores were collected. Instrumented levels, estimated blood loss, major and minor complications, length of hospitalization, and hospital discharge status were also reviewed and compared.

RESULTS

A total of 66 patients were overweight (BMI > 25-29.9; average, 26.9) (Group OW), whereas 38 patients were obese (BMI > 30; average, 33.5) (Group OB). The average age was 54.5 in Group OW and 48.6 in Group OB (p < .01). Postoperatively, significant changes were not found in the BMI for Group OW, 27.2 (26.9-27.2; p < .39), and for Group OB, 35 (33.5-35; p < .06). Postoperatively, significant improvements were seen in both groups for Oswestry Disability Index (36.1-21.8, Group OW; 44.1-24.4, Group OB; p <.001), SRS self-image (2.9-3.7, Group OW; 2.6-3.8, Group OB; p < .001) and SRS score (3.1-3.8, Group OW; 2.9-3.8, Group OB; p < .001). There were no significant differences in complications between groups.

CONCLUSIONS

As a group, overweight and obese primary spinal deformity patients did not demonstrate significant weight gain or weight loss from preoperative to latest follow-up. However, both overweight and obese patients had significant improvements in outcome scores at latest follow-up and equivalent rates of complications.

Proximal junctional kyphosis results in inferior SRS pain subscores in adult deformity patients

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

We aimed to examine the difference in clinical outcomes in proximal junctional kyphosis (PJK).

SUMMARY OF BACKGROUND DATA

To date, PJK has been primarily a radiographical finding. Inferior outcomes associated with PJK have not been reported. We performed an analysis of PJK in adult deformity patients to identify risk factors and to evaluate clinical outcomes.

METHODS

A total of 364 patients at a single institution from 2002 to 2007 with adult scoliosis, with an average 3.5 years' follow-up were analyzed. Inclusion criteria were age more than 18 years and fusion greater than 5 levels from any thoracic upper instrumented vertebrae to any lower instrumented vertebrae. Cobb measurements in the coronal and sagittal plane in addition to measurements of the PJK angle at postoperative time points were performed. Clinical assessment was performed using Scoliosis Research Society (SRS) scores and the Oswestry Disability Index.

RESULTS

The prevalence of PJK was 39.5% (144/364). The average age in the non-PJK group (n-PJK) was 48.9 versus 53.3 in the PJK group (PJK), and, specifically, age more than 60 years posed a higher prevalence. The prevalence of osteoporosis was 9.8% versus 20.4% in the n-PJK versus PJK groups, respectively. Sex, body mass index, revision surgery, and smoking status were not different between groups. Pain was prevalent in 0.9% versus 29.4% in n-PJK versus PJK, which resulted in lower composite SRS Pain scores (mean change +1.2 vs. +0.8), despite no differences seen in other SRS domains, total SRS score, or Oswestry Disability Index. On multivariate analysis, the presence of pain of the upper back was highly predictive of PJK (odds ratio, 12.5, 95% confidence interval, 2.5-63.2). Radiographically, no differences were seen between groups. However, increasing distance of the upper instrumented vertebrae to C7 plumb line had a higher prevalence of PJK. Instrumentation type, surgical approach, and crosslink use were not different between groups.

CONCLUSION

PJK results in worse clinical outcomes measured by the SRS Pain subscore. Our regression model suggests that pain in the upper back has a strong predictive value for PJK.

LEVEL OF EVIDENCE

3.

Decompression alone versus decompression with limited fusion for treatment of degenerative lumbar scoliosis in the elderly patient

STUDY DESIGN

 Retrospective cohort study.

OBJECTIVE

 To analyze the surgical results of a group of patients older than 65 years treated for mild degenerative lumbar scoliosis (<30°) with stenosis, treated with decompression alone or decompression and limited fusion.

METHODS

 We evaluated 55 patients, all older than 65 years from our prospectively collected database with mild degenerative scoliosis (<30°) and stenosis who underwent surgery. Laminectomy alone was performed in 16 patients, and laminectomy and limited fusion in 39 patients. Mean follow-up was 4.6 years in the decompression group and 5.0 years in the fusion group. Clinical results were graded by patients' self-reported satisfaction and length of symptom-free period to recurrence.

RESULTS

 In the decompression alone group, 6 (37%) of 16 patients developed recurrent stenosis at the previously decompressed level and five developed recurrence within 6 months postoperatively versus the decompression and fusion group where 3 (8%) of 39 (P = .0476) developed symptomatic stenosis supra adjacent to the fusion. Of 16 patients in the decompression alone group, 12 (75%) had recurrence of symptoms by the 5-year follow-up period versus only 14 (36%) patients in the decompression and fusion group (P = .016). Adjacent segment degenerative changes were common in the fusion group, but only 7% developed symptomatic stenosis.

CONCLUSIONS

 Decompression with limited fusion prevents early return of stenotic symptoms compared with decompression alone in the setting of mild degenerative scoliosis (<30°) and symptomatic stenosis in patients 65 years and older. [Table: see text] The definiton of the different classes of evidence is available on page 67.

Preoperative Halo-Gravity Traction for Severe Pediatric Spinal Deformity: Complications, Radiographic Correction and Changes in Pulmonary Function

BACKGROUND SUMMARY

The use of preoperative halo-gravity traction (HGT) improves both spinal deformity and pulmonary function and is a helpful adjuvant in the treatment of complex spinal deformity. Despite the benefits of preoperative HGT, there is no consensus on the optimal traction protocol.

METHODS

We evaluated the treatment of 33 patients treated with preoperative HGT to determine the safety and efficacy of preoperative HGT with regards to deformity correction; to quantify changes in pulmonary function; and to better define an ideal preoperative traction protocol. All patients were treated at the same tertiary-care pediatric hospital between 1998 and 2007. Inclusion criteria were preoperative HGT (before anterior and/or posterior spinal fusion), pretraction spinal Radiographs, repeat Radiographs taken during the traction period, and repeat Radiographs taken at the completion of traction and final Radiographs after surgical correction. The average duration of preoperative HGT was 70.1 days. The average traction weight applied was 38.5% of total body weight. Maximal traction weight was achieved in an average of 30.5 days.

RESULTS

Our results, 35% correction of the coronal Cobb and 35% correction of the sagittal Cobb, are consistent with others reported in the literature. Pulmonary function tests taken before and after traction were available for 22 patients. Treatment with HGT improved pulmonary function results in 19 patients. There were no serious complications.

CONCLUSION

We found that preoperative HGT is a safe and useful adjuvant to the treatment of patients with severe scoliosis. Significant deformity correction averaging 35% percent can be expected, with the majority of deformity correction occurring after 3 to 4 weeks. In the majority of patients, this correction is maintained or even improved with subsequent surgical correction.

Clinical and radiographic parameters that distinguish between the best and worst outcomes of scoliosis surgery for adults

PURPOSE

Predictors of marked improvement versus failure to improve following surgery for adult scoliosis have not been identified. Our objective was to identify factors that distinguish between patients with the best and worst outcomes following surgery for adult scoliosis.

METHODS

This is a secondary analysis of a prospective, multicenter spinal deformity database. Inclusion criteria included: age 18-85, scoliosis (Cobb ≥ 30°), and 2-year follow-up. Based on the Oswestry Disability Index (ODI) and the SRS-22 at 2-year follow-up, patients with the best and worst outcomes were identified for younger (18-45) and older (46-85) adults with scoliosis. Clinical and radiographic factors were compared between patients with the best and worst outcomes.

RESULTS

276 patients met inclusion criteria (89 younger and 187 older patients). Among younger patients, predictors of poor outcome included: depression/anxiety, smoking, narcotic medication use, older age, greater body mass index (BMI) and greater severity of pain prior to surgery. Among older patients, predictors of poor outcome included: depression/anxiety, narcotic medication use, greater BMI and greater severity of pain prior to surgery. None of the other baseline or peri-operative factors assessed distinguished the best and worst outcomes for younger or older patients, including severity of deformity, operative parameters, or the occurrence of complications.

CONCLUSIONS

Not all patients achieve favorable outcomes following surgery for adult scoliosis. Baseline and peri-operative factors distinguishing between patients with the best and worst outcomes were predominantly patient factors, including BMI, depression/anxiety, smoking, and pain severity; not comorbidities, severity of deformity, operative parameters, or complications.

Does prior short-segment surgery for adult scoliosis impact perioperative complication rates and clinical outcome among patients undergoing scoliosis correction?

Object

In many adults with scoliosis, symptoms can be principally referable to focal pathology and can be addressed with short-segment procedures, such as decompression with or without fusion. A number of patients subsequently require more extensive scoliosis correction. However, there is a paucity of data on the impact of prior short-segment surgeries on the outcome of subsequent major scoliosis correction, which could be useful in preoperative counseling and surgical decision making. The authors' objective was to assess whether prior focal decompression or short-segment fusion of a limited portion of a larger spinal deformity impacts surgical parameters and clinical outcomes in patients who subsequently require more extensive scoliosis correction surgery.

Methods

The authors conducted a retrospective cohort analysis with propensity scoring, based on a prospective multicenter deformity database. Study inclusion criteria included a patient age ≥ 21 years, a primary diagnosis of untreated adult idiopathic or degenerative scoliosis with a Cobb angle ≥ 20°, and available clinical outcome measures at a minimum of 2 years after scoliosis surgery. Patients with prior short-segment surgery (< 5 levels) were propensity matched to patients with no prior surgery based on patient age, Oswestry Disability Index (ODI), Cobb angle, and sagittal vertical axis.

Results

Thirty matched pairs were identified. Among those patients who had undergone previous spine surgery, 30% received instrumentation, 40% underwent arthrodesis, and the mean number of operated levels was 2.4 ± 0.9 (mean ± SD). As compared with patients with no history of spine surgery, those who did have a history of prior spine surgery trended toward greater blood loss and an increased number of instrumented levels and did not differ significantly in terms of complication rates, duration of surgery, or clinical outcome based on the ODI, Scoliosis Research Society-22r, or 12-Item Short Form Health Survey Physical Component Score (p > 0.05).

Conclusions

Patients with adult scoliosis and a history of short-segment spine surgery who later undergo more extensive scoliosis correction do not appear to have significantly different complication rates or clinical improvements as compared with patients who have not had prior short-segment surgical procedures. These findings should serve as a basis for future prospective study.