Nutritional improvement following growing rod surgery in children with early onset scoliosis

Elective musculoskeletal surgery is associated with postoperative weight changes in pediatric and adolescent patients

Purpose

Patients of elective orthopedic surgeries often reduce activity levels during postoperative recovery. It is unclear whether these extended periods of modified activities lead to weight changes. The purpose of this study was to evaluate changes in body mass index percentile in pediatric patients over 2.5 years following primary musculoskeletal surgeries.

Methods

Institutional records for utilized current procedural terminology codes were used to identify patients aged 21 years or younger who underwent elective surgery at a single pediatric orthopedic institution between October 2016 and December 2018. Non-primary surgeries and patients without preoperative body mass index measurements were excluded. Demographic characteristics, height, weight, and body mass index within 30 months of surgery were collected. Body mass index relative to age was calculated. Analysis of body mass index changes at follow-up intervals of 3-7, 9-18, and 24-30 months after surgery was performed for the overall sample, within surgical categories, and within preoperative weight classifications.

Results

A total of 1566 patients (53.1% female, average age 12.4 years) were included. Over one-third of patients were overweight or obese at presentation. The average change in body mass index percentile relative to baseline was increased at all follow-up intervals. Values reached significance at 9-18 months (p = .002) and 24-30 months (p = .001). While underweight and normal-weight patients had increased body mass index at all three timepoints, overweight or obese patients decreased.

Conclusions

Patients undergoing elective orthopedic procedures may experience significant changes in body mass index percentile postoperatively. At extremes of weight, patients experience improvement toward the mean, but most patients may undergo body mass index increases beyond what would be expected during normal growth.

Level of evidence

Retrospective level III.

Halo-pelvic traction in the treatment of severe scoliosis: a meta-analysis

PURPOSE

To provide better evidence of the efficacy and safety of preoperative halo-pelvic traction on the improvements of deformity and pulmonary functions in patients with severe scoliosis.

METHODS

Electronic database searches were conducted including the Cochrane Library, PubMed, Web of Science and Embase. All studies of halo-pelvic traction for the management of severe spinal deformity were included. We referred to a list of four criteria developed by the Agency for Healthcare Research and Quality (AHRQ) to assess the quality of included studies. The meta-analysis was performed using RevMan 5.4 software.

RESULTS

Based on the study selection criteria, a total of eight articles consisting of a total of 210 patients were included. Statistically significant differences were found in coronal Cobb angle (P < 0.001), sagittal Cobb angle (P < 0.001) and height (P < 0.001) between pre- and post-traction. Sensitivity analysis was conducted, and there were substantial changes in heterogeneity with preoperative thoracoplasty subgroup in coronal Cobb angle (P < 0.001). Three trials including 74 subjects reported FVC and FEV1 predicted value between pre- and post-traction. There were statistically significant differences in FVC, FVC%, FEV1 and FEV1% (P < 0.001). The complication rate was 6.6-26.7%, and symptoms disappeared after reasonable traction strategy and intensive care.

CONCLUSIONS

Preoperative halo-pelvic traction achieved significant improvements in spinal deformity and pulmonary functions, with minor and curable complications. Thus, it is an effective and safe solution before surgery and may be the optimal choice for severe scoliosis. In light of the heterogeneity and limitations, future researches are needed to better determine the long-term efficacy on comprehensive assessment and to explore the appropriate traction system.

Weight gain and gastrostomy tube safety during serial body casting for early onset scoliosis

PURPOSE

Serial casting has been shown to improve curve deformity for patients with early-onset scoliosis (EOS). However, despite prior literature demonstrating the importance of weight and nutrition in EOS patients, there is limited information regarding complications and weight gain ability for children undergoing serial casting. Additionally, parents of patients undergoing serial casting often have concerns regarding weight gain and patient comfort, which tend to be amplified in patients with gastrostomy tubes (g-tubes). We aim to understand changes in weight, g-tube complications, and cast-related complications in patients being treated with serial casting.

METHODS

A single center retrospective review of all EOS patients less than 6 years old treated with serial casting was performed. Patient weight out of cast throughout their treatment was converted to a percentile based on CDC growth charts. Patients with documented calls regarding cast concerns, complications requiring cast removal, or g-tube procedures were recorded.

RESULTS

A total of 32 patients treated with serial casting were included with four having g tubes. Overall, the average weight percentile increased from pre-casting to post-casting (27-38%, p < 0.001) with 21 patients showing an increase. Of the 22 patients with a starting weight below the 25th percentile, 14 (64%) demonstrated an increase. Patients with g tubes increased an average of 4.2 kg during casting compared to 3.0 kg in patients without g tubes (p = 0.588). 18 parents registered a cast concern during the treatment and 5 patients required at least one early cast removal. No difference in cast concerns (p = 0.597) or cast removals (p = 0.488) was observed when comparing patients with g tubes to those without. There were no instances of g-tube dysfunction during casting.

CONCLUSION

While the average weight percentile for patients initiating serial casting is below average, the majority increased their weight percentile during treatment. Patients with and patients without g tubes were able to maintain or gain weight during casting treatment. While it was common for parents to contact providers with cast concerns, patients with g tubes did not appear to have a greater risk of cast or g tube-related complications.

LEVEL OF EVIDENCE

Level IV.

Cost-Utility Analysis of Anterior Vertebral Body Tethering versus Spinal Fusion in Idiopathic Scoliosis from a US Integrated Healthcare Delivery System Perspective

Purpose

Anterior vertebral body tethering (VBT) is a non-fusion, minimally invasive, growth-modulating procedure with some early positive clinical outcomes reported in pediatric patients with idiopathic scoliosis (IS). VBT offers potential health-related quality of life (HRQoL) benefits over spinal fusion in allowing patients to retain a greater range of motion after surgery. We conducted an early cost-utility analysis (CUA) to compare VBT with fusion as a first-choice surgical treatment for skeletally immature patients (age >10 years) with moderate to severe IS, who have failed nonoperative management, from a US integrated healthcare delivery system perspective.

Patients and Methods

The CUA uses a Markov state transition model, capturing a 15-year period following index surgery. Transition probabilities, including revision risk and subsequent fusion, were based on published surgical outcomes and an ongoing VBT observational study (NCT02897453). Patients were assigned utilities derived from published patient-reported outcomes (PROs; SRS-22r mapped to EQ-5D) following fusion and the above VBT study. Index and revision procedure costs were included. Probabilistic (PSA) and deterministic sensitivity analyses (DSA) were performed.

Results

VBT was associated with higher costs but also higher quality-adjusted life years (QALYs) than fusion (incremental costs: $45,546; QALYs gained: 0.54). The subsequent incremental cost-effectiveness ratio for VBT vs fusion was $84,391/QALY gained. Mean PSA results were similar to the base case, indicating that results were generally robust to uncertainty. The DSA indicated that results were most sensitive to variations in utility values.

Conclusion

This is the first CUA comparing VBT with fusion in pediatric patients with IS and suggests that VBT may be a cost-effective alternative to fusion in the US, given recommended willingness-to-pay thresholds ($100,000–$150,000). The results rely on HRQoL benefits for VBT compared with fusion. For improved model accuracy, further analyses with longer-term PROs for VBT, and comparative effectiveness studies, would be needed.

Growing-rod implantation improves nutrition status of early-onset scoliosis patients: a case series study of minimum 3-year follow-up

BACKGROUND

Early onset scoliosis (EOS) may cause malnutrition in affected patients. Growing-rod treatment has been an effective protocol for treating EOS. The objective of this study is to demonstrate whether growing-rod treatment improves nutritional status of EOS patients.

METHODS

Fifty-two EOS patients who had dual growing-rod surgery was enrolled. The minimum follow-up was 3-years. Their body weights were normalized based on the data of two National Population Census of China. Z-scores were used to indicate the standard deviation from the median body weight-for-age.

RESULTS

The median follow-up time was 6 years. Preoperatively, the prevalence of malnutrition (Z < - 2) was 21.2%, and reduced to 9.6% at the end of the follow-up. Preoperatively, the average Z-score was - 0.94, and it increased to - 0.65 at the latest follow-up (p < 0.05). Patients with preoperative Z-score below - 1 had more significant increase of Z-scores (- 2.15 vs - 1.26, p < 0.001). A significant negative correlation between the change of Z-score and the preoperative Z-score (correlation coefficient - 0.65, p < 0.001).

CONCLUSIONS

The growing rod surgery and lengthening procedures significantly improves the nutrition status of EOS patients. The body weight gains are more significant in patients with lower body weights.

Complications in the treatment of EOS: Is there a difference between rib vs. spine-based proximal anchors?

INTRODUCTION

Currently, there is significant equipoise regarding the selection and placement of growing spinal instrumentation when treating patients with early-onset scoliosis (EOS). The primary purpose of this study was to compare complications following surgery in patients receiving rib-based versus spine-based proximal anchors as a part of posterior growing instrumentation in the management of EOS.

METHODS

Retrospective cohort study. Inclusion criteria required: age 3-10 years old, diagnosis of EOS, treatment with a growing construct that utilized rib- or spine-based proximal anchors, and a major coronal curve larger than 40 degrees. The primary outcome analyzed was postoperative complications. Secondary outcomes included coronal major curve correction and patient reported outcomes measured by the Early-Onset Scoliosis 24-item Questionnaire (EOSQ-24). Subjects were categorized into rib- or spine-based proximal fixation groups for comparison.

RESULTS

Of 104 patients included in the study, 76 (73.1%) were treated with rib-based constructs and 28 (26.9%) were treated with spine-based constructs. 24 (31.6%) patients with rib-based constructs and 9 (32.1%) patients with spine-based constructs experienced at least one implant related complication (p = 0.956). Rod fracture was observed more often in spine-based groups than rib-based groups for both patients with congenital/idiopathic EOS (rib: 0 (0%) vs. spine: 3 (13.6%), p = 0.009) and neuromuscular/syndromic EOS (rib: 0 (0%) vs. spine: 2 (33.3%), p = 0.002). Furthermore, surgical site infection was found to be more frequent in rib-based than spine-based groups for neuromuscular/syndromic patients (rib: (13) 27.15 vs. spine: (1) 4.5%, p = 0.029). The most commonly reported complication was device migration. In patients with rib-based constructs, 2 (12.5%) patients with ≥ 5 anchors and 13 (21.7%) patients with < 5 anchors experienced device migration (p = 0.413). In patients with spine-based constructs, 1 (11.1%) patient with ≥ 5 anchors and 4 (21.1%) patients with < 5 anchors experienced device migration (p = 0.064). Spine-based anchors had significantly higher% correction (42.0%) compared to rib-based anchors (20.6%) (p = 0.003) at the most recent follow-up. There were no significant differences in the change of patient reported outcomes as measured by the EOSQ-24 between patients who received rib or spine-based anchors.

DISCUSSION

The number of patients with at least one implant related complication was similar between the rib- and spine-based groups. Having 5 or more proximal anchors appeared protective against proximal device migration; however, this result was not statistically significant. Spine-based anchors had better overall correction than rib-based anchors. There were no differences in the change in patient reported outcomes between spine- and rib-based cohorts.

BMI change following spinal fusion for neuromuscular scoliosis surgery

STUDY DESIGN

Retrospective descriptive, multi-center study.

OBJECTIVES

We hypothesize that a post-operative weight gain will result in patients who are underweight prior to surgery. Cachexia and low body mass index is common among children with cerebral palsy (CP). Many interventions are undertaken to assist the child in nourishment and to obtain a more normal body mass. Additionally, scoliosis is common among children with CP. In our practice we have noted weight gain post operatively in severely underweight children after spinal fusion.

METHODS

We underwent a retrospective review of a CP cohort from a multicenter prospective registry. Percentiles on the CP specific growth chart for which each child belonged were plotted based on the patients' age, weight, gender, GMFCS level, and tube feeding status. We then assessed percentile change in patients between pre-op visit, 1 year, 2 years and for those with available data, 5 years follow up visits. Patients with under two years of follow up, patients with GMFCS III and below, and patients without weight data were excluded.

RESULTS

We identified a total of 211 potentially eligible patients from a multicenter prospective registry. 109 had complete 2 years data to analyze and 37 patients had full 5 years data to analyze. We found that patients under the 50th percentile pre-operatively increased their percentile on the CP growth chart for weight 12.1 percentiles (95% CI 6.7, 17.5 p value < 0.001) whereas patients that began at the 50th percentile or above on average lost 2.2 percentiles (95% CI -6.8, 2.3) though the change was not statistically significant (p value 0.330). These changes appeared stable at 5 years. Although regression analysis showed that Cobb correction and pelvic obliquity correction, and hyperlordosis were not independent predictors of the change, we noted that patients with residual curves after surgery of 40° or more experienced 13.3 percentile less weight gain than those with better corrections.

CONCLUSIONS

Patients with CP are at risk for cachexia, malnutrition, reflux and other GI disorders. Data presented here suggests that corrective spinal surgery may improve weight percentile in patients who start out at 50th percentile and lower. Patients with 40° or greater of residual scoliosis may benefit less from spinal fusion than those with a better correction.

LEVEL OF EVIDENCE

II; Prognostic retrospective cohort study.

Releasing the tether: Weight normalization following corrective spinal fusion in cerebral palsy

PURPOSE

Feeding difficulties are common among patients with cerebral palsy (CP) and neuromuscular (NM) scoliosis. We theorize that posterior spinal fusion (PSF) reduces intra-abdominal pressure, resulting in improved feeding and subsequent weight gain. We hypothesized that, among nonambulatory patients with CP and NM scoliosis, we would observe significant gain in weight following PSF.

METHODS

Fifty subjects with nonambulatory CP who underwent PSF for NM scoliosis were included. Age and weight were recorded for the preoperative year; on the day of surgery; and at 6-month, 1-year, and 2-year follow-up. Weights were converted to weight percentiles using CP-specific growth charts. The weight percentile distributions were compared between time points using descriptive statistics as well as regression analysis.

RESULTS

The average change in weight from the day of surgery to 2-year follow-up was +3.4 percentiles. Patients who started out under the 50th percentile gained an average of 17.3 percentiles in the first year after PSF ( p = 0.009). Regression analysis showed that patients with baseline weight <50th percentile tended to gain in weight percentile over the first postoperative year ( β = 1.990, p = 0.001). No trend was present among this group prior to surgery ( p = 0.692) or during the second postoperative year ( p = 0.945). No trends were noted prior to or after surgery for patients with baseline weights ≥50th percentile. No significant association was observed between curve severity (measured by preoperative Cobb angle) and weight change.

CONCLUSIONS

This series is the first to document significant weight gain after PSF for NM scoliosis, supporting the theory that spinal correction improves digestive function.

LEVEL OF EVIDENCE

Prognostic level II.

Radiographic, Pulmonary, and Clinical Outcomes With Halo Gravity Traction

STUDY DESIGN

Single-center retrospective chart review.

OBJECTIVES AND SUMMARY

Halo gravity traction (HGT) is a safe and effective intervention to improve spinal deformity prior to corrective instrumentation. Our study aimed to report on a large series of patients undergoing HGT, demonstrate the correlation between thoracic height achieved and pulmonary function, and evaluate the efficacy of nutritional assessment and intervention while in HGT for these often malnourished or nutritionally compromised patients.

METHODS

107 patients underwent HGT for severe spinal deformity. Major coronal and sagittal Cobb angles, T1-T12 ht, and T1-S1 ht were collected pre-HGT, during HGT, postoperation, and 2 years postoperation. Pulmonary function tests (PFTs) recorded forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1). Nutritional interventions such as formal nutrition consult, resulting nutritional supplementation, or interventions were recorded.

RESULTS

Patients were in HGT for mean of 82.1 days and mean maximum percentage body weight in traction was 49.5%. Mean major coronal Cobb angle prior to HGT was 92.6°, improving to 65.8° in maximal traction and to 47° after surgical intervention. Traction accounted for 78% of T1-T12 height and 79% of T1-S1 length gains from pre- to postoperation. We showed a positive correlation between gain in T1-T12 height and percentage predicted changes in FVC and FEV1. Weight Z score for the entire cohort of patients improved from -2.8 pretraction to -2.4 in traction and then to -2.3 postoperative.

CONCLUSIONS

Our study again demonstrated that HGT achieves radiographic improvement safely and effectively in severe spinal deformity. We demonstrated a positive correlation between improvement in PFTs and increase in thoracic height seen with HGT. Additionally, improvement in weight Z score was seen in the entire population and the most at risk patients for malnutrition, results that have not been shown before.

LEVEL OF EVIDENCE

Level IV.

Comparison of Percentile Weight Gain of Growth-Friendly Constructs in Early-Onset Scoliosis

STUDY DESIGN

Multicenter retrospective cohort.

OBJECTIVE

To compare improvement in nutritional status seen in early-onset scoliosis (EOS) patients following treatment with various growth-friendly techniques, especially in underweight patients (<20th weight percentile).

BACKGROUND

Thoracic insufficiency resulting from EOS can lead to severe cardiopulmonary disease. In this age group, pulmonary function tests are often difficult or impossible to perform. Weight gain has been used in prior studies as a proxy for improvement and has been demonstrated following VEPTR and growing rod implantation. In this study, we aim to analyze weight gain of EOS patients treated with four different spinal implants to evaluate if significant differences in weight percentile change exist between them.

METHODS

Retrospective review of patients treated surgically for EOS was performed from a multicenter database. Exclusion criteria were index instrumentation at >10 years old and <2 years' follow-up.

RESULTS

287 patients met the inclusion criteria and etiologies were as follows: congenital = 85; syndromic = 79; neuromuscular = 69; and idiopathic = 52. Average patient age at surgery was 5.41 years, with an average follow-up of 5.8 years. Preoperatively, 55.4% (162/287) fell below the 20th weight percentile. There was no significant difference in preoperative weight between implants (p = .77), or diagnoses (p = .25). Among this group, the mean change in weight percentile was 10.5% (range: -16.7% to 88.7%) and all implant groups increased in mean weight percentile at final follow-up. There were no significant differences in weight percentile change between the groups when divided by implant type (p = .17).

CONCLUSIONS

Treatment of EOS with growth-friendly constructs resulted in an increase in weight percentile for underweight patients (<20th percentile), with no significant difference between constructs.

LEVEL OF EVIDENCE

Level III.

Weight Gain After Vertical Expandable Prosthetic Titanium Rib Surgery May Be From Nutritional Optimization Rather Than Improvement in Pulmonary Function

STUDY DESIGN

Prospective comparative study.

OBJECTIVE

To evaluate whether weight percentile (WP) increases after vertical expandable prosthetic titanium rib (VEPTR) insertion, and whether WP correlates with nutrition laboratories and pulmonary function.

SUMMARY OF BACKGROUND DATA

Children with thoracic insufficiency syndrome often have "failure to thrive" (WP ≤5). Previous authors have reported an increase in WP after VEPTR surgery. Weight gain was hypothesized to be secondary to improved pulmonary function. The presence of a correlation between WP and nutrition laboratories and pulmonary function tests (PFT) after VEPTR insertion has not been studied.

METHODS

Demographic, nutrition, radiographic, and PFT data were collected on 35 VEPTR patients with a minimum follow-up of 2 years. The relationship between WP and nutrition laboratories and pulmonary function was analyzed.

RESULTS

Preoperative WP was ≤5 (PREOP≤5) in 13 patients (37%) and >5 (PREOP>5) in 22 patients (63%). Although all children gained weight, the PREOP≤5 group was more likely to have an increase in WP (P = 0.014). Sixty-eight percent of the PREOP>5 group had a decrease in WP and 32% of the PREOP>5 patients met the criteria for failure to thrive at final follow-up. Overall, there was no change in the number of children with a WP ≤5 (13 vs. 15). Forty-two percent of the children who maintained or increased their WP had a gastrostomy tube, compared to 19% of those who decreased their WP. Seventy-three percent of the patients with failure to thrive at final follow-up did not have a gastrostomy tube. No significant correlations were found between WP and nutrition laboratories, radiographic measures, or PFTs.

CONCLUSION

We did not find an overall change in WP after VEPTR insertion. We did not find any correlation between WP and nutrition laboratories or pulmonary function. Weight gain after VEPTR surgery may be secondary to nutritional optimization in high-risk patients. Children who do not have failure to thrive at presentation also require attention.

LEVEL OF EVIDENCE

2.

Complications and Radiographic Outcomes of Posterior Spinal Fusion and Observation in Patients Who Have Undergone Distraction-Based Treatment for Early Onset Scoliosis

STUDY DESIGN

Retrospective, multicenter.

OBJECTIVES

To compare surgical and radiographic outcomes of early-onset scoliosis (EOS) patients who had stopped lengthening for ≥2 years without additional surgery to those who had posterior spinal fusion (PSF) at the end of lengthening.

SUMMARY OF BACKGROUND DATA

Because of the risk of significant complications with PSF in patients with EOS, "watchful waiting" at the end of lengthening has been suggested as a viable alternative.

METHODS

Retrospective review of the Children's Spine Study Group (CSSG) database identified all patients with the diagnosis of EOS who had distraction-based treatment, who were ≥2 years from their last distraction, and who had complete records. Radiographic measures were obtained by a single unbiased trained observer. Treatment outcomes including curve correction, height and length gain, as well as complications were recorded.

RESULTS

The 37 patients (21 females and 16 males) had a mean age of 7.2 years; 12 were in the observation (OBS) and 25 in the PSF group. The PSF group had a slightly greater coronal Cobb angle and maximal kyphosis at the end of distraction. Although there was some correction of the coronal Cobb angle and maximal kyphosis following PSF, the differences between the two groups were not statistically significant at final follow-up. At final follow-up, the OBS group obtained 88% of T1-T12 height and 90% of T1-L1 length of that obtained by the PSF group. Twenty-six complications occurred in 15 patients, all in the PSF group.

CONCLUSIONS

Observation may be a viable alternative to PSF after distraction-based treatment in a subset of patients with EOS. PSF was found to provide no significant curve correction or gains in spine height and length compared to observation and carries a significant risk of complications.

LEVEL OF EVIDENCE

Level III, therapeutic.

Early-Onset Scoliosis: A Review of History, Current Treatment, and Future Directions

Early-onset scoliosis (EOS) is defined as curvature of the spine in children >10° with onset before age 10 years. Young children with EOS are at risk for impaired pulmonary function because of the high risk of progressive spinal deformity and thoracic constraints during a critical time of lung development. The treatment of EOS is very challenging because the population is inhomogeneous, often medically complex, and often needs multiple surgeries. In the past, early spinal fusion was performed in children with severe progressive EOS, which corrected scoliosis but limited spine and thoracic growth and resulted in poor pulmonary outcomes. The current goal in treatment of EOS is to maximize growth of the spine and thorax by controlling the spinal deformity, with the aim of promoting normal lung development and pulmonary function. Bracing and casting may improve on the natural history of progression of spinal deformity and are often used to delay surgical intervention or in some cases obviate surgery. Recent advances in surgical implants and techniques have led to the development of growth-friendly implants, which have replaced early spine fusion as the surgical treatment of choice. Treatment with growth-friendly implants usually requires multiple surgeries and is associated with frequent complications. However, growth-friendly spine surgery has been shown to correct spinal deformity while allowing growth of the spine and subsequently lung growth.