Risk Factors for Reoperation Following Final Fusion After the Treatment of Early-Onset Scoliosis with Traditional Growing Rods

BACKGROUND

Although there is a high rate of reoperation after final fusion following the treatment of early-onset scoliosis with use of traditional growing rods, the risk factors for reoperation are unknown. The purpose of the present study was to identify risk factors associated with the need for reoperation after final fusion for the treatment of early-onset scoliosis.

METHODS

A multicenter database for patients with early-onset scoliosis was retrospectively analyzed. Patients managed with traditional growing rods and final fusion were identified (n = 248). The inclusion criteria were ≥1 lengthening procedure with traditional growing rods and ≥2 years of follow-up after final fusion or revision surgery within 2 years after final fusion (167 patients; 67%). Patients requiring reoperation following final fusion were compared with patients who did not require reoperation. The data that were analyzed included demographic characteristics, comorbidities, spinal deformity characteristics, radiographic measurements, perioperative details, and complications during all stages of treatment. A multivariate regression model was used to identify independent risk factors.

RESULTS

The mean duration of follow-up from the initial visit to the latest visit was 10.7 ± 4.1 years, and the mean duration of follow-up after final fusion was 4.9 ± 3.1 years. Thirty-two (19%) of the 167 patients required reoperation following final fusion. Curve progression requiring revision surgery during lengthening with traditional growing rods (adjusted odds ratio [aOR], 21.137 per event; p = 0.028), the number of levels spanned with traditional growing rods (aOR, 1.378 per level; p = 0.007), and the duration of treatment with traditional growing rods (aOR, 1.220 per year; p = 0.035) were independently associated with revision surgery after final fusion.

CONCLUSIONS

Independent risk factors for curve progression requiring reoperation during lengthening with traditional growing rods that require operative intervention include increasing number of levels spanned with traditional growing rods and longer duration of treatment with traditional growing rods. These findings may help with patient counseling and potentially guide surgeon decision-making.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

One stage or two? A cohort analysis of anterior-posterior spinal fusions for severe pediatric scoliosis

STUDY DESIGN

Retrospective case-series study of prospectively collected data.

OBJECTIVE

We sought to identify the differences in outcomes between one-stage (single surgical episode) and two-stage (separate day) anterior and posterior spinal fusion and segmental spinal instrumentation surgeries in severe non-idiopathic and idiopathic scoliosis cases.

BACKGROUND

Patients with severe pediatric spine deformity may require combined anterior and posterior fusion procedures. Given their increased complexity and morbidity, surgeons may consider staging these procedures on separate days.

METHODS

A retrospective cohort study was performed on a prospective Pediatric Spine Database. Patients 21 years of age or under with pediatric scoliosis who underwent primary anterior and posterior spinal deformity correction surgery either through a one-stage or planned two-stage sequence with greater than 2-year follow-up were included. Differences in demographics, comorbidities, surgical details, perioperative morbidity, complications, and outcomes were assessed based on scoliosis etiology. Multivariate models were utilized to control for confounders.

RESULTS

There were 70 non-idiopathic (14 two-stage vs. 56 one-stage) and 65 idiopathic scoliosis (8 two-stage vs. 57 one-stage) patients. Mean follow-up was 90.1  ± 54.7 months. In non-idiopathic scoliosis patients, two-stage surgery was independently associated with a 140-min increased surgical time (95% confidence interval: 52-229 min, p = 0.002) and an 8.2-day (95% confidence interval: 2.3-14.1 days, p = 0.007) increased hospital length of stay. In idiopathic scoliosis patients, two-stage surgery was independently associated with a 2108 ml increase in crystalloid use (95% confidence interval: 834-3381 ml p = 0.002) and a 5.3-day increased hospital length of stay (95% confidence interval: 4.0-6.5 days, p < 0.001). There were no significant differences in blood loss, transfusions, complications, or post-operative curves on multivariate analysis between one-stage and two-stage surgery cohorts in either non-idiopathic or idiopathic scoliosis patient groups.

CONCLUSION

Two-stage surgery was associated with increased crystalloid use in idiopathic scoliosis patients and longer operative times in non-idiopathic scoliosis patients, and longer hospital length of stay in both populations, without significant difference in complications or deformity correction. In the appropriate patient, one-stage anterior-posterior scoliosis surgery may be preferable to two-stage surgery.

LEVEL OF EVIDENCE

Level III Retrospective Comparative Study.

Surgical site infection prevention protocol for pediatric spinal deformity surgery: does it make a difference?

STUDY DESIGN

Retrospective.

OBJECTIVE

Can a standardized, hospital-wide care bundle decrease surgical site infection (SSI) rate in pediatric spinal deformity surgery? SSI is a major concern in pediatric spinal deformity surgery.

METHODS

We performed a retrospective review of our primary scoliosis surgeries between 1999 and 2017. In 2008, we implemented a standardized infection reduction bundle. Interventions included preoperative nares screening for methicillin-resistant staphylococcus aureus or methicillin-sensitive Staphylococcus aureus 2 weeks preoperatively, and treatment with intranasal mupirocin when positive, a bath or shower the night before surgery, a preoperative chlorohexidine scrub, timing of standardized antibiotic administration, standardized intraoperative re-dosing of antibiotics, limiting operating room traffic, and standardized postoperative wound care. In 2011, we added intrawound vancomycin powder at wound closure. Our inclusion criteria were patients 21 years of age or less with idiopathic, neuromuscular, syndromic, or congenital scoliosis who had a primary spinal fusion or a same day anterior and posterior spine fusion with segmental spinal instrumentation of six levels or more. We compared the incidence of early (within 90 days of surgery) and late (> 91 days) SSI during the first postoperative year.

RESULTS

There were 804 patients who met inclusion criteria: 404 in the non-bundle group (NBG) for cases prior to protocol change and 400 in the bundle group (BG) for cases after the protocol change. Postoperatively, there were 29 infections (7.2% of total cases) in the NBG: 9 early (2.2%) and 20 late (5.0%) while in the BG there were only 10 infection (2.5%): 6 early (1.5%) and 4 late (1.0%). The reduction in overall SSIs was statistically significant (p = 0.01). There was a trend toward decreased early infections in the BG, without reaching statistical significance (p = 0.14).

CONCLUSION

Standardized care bundles appear effective in reducing the incidence of postoperative pediatric spine SSIs.

LEVEL OF EVIDENCE

Level III.

Growth-preserving instrumentation in early-onset scoliosis patients with multi-level congenital anomalies

STUDY DESIGN

Retrospective.

OBJECTIVES

To assess final outcomes in patients with early-onset scoliosis (EOS) who underwent growth-preserving instrumentation (GPI). Various types of growth-preserving instrumentation (GPI) are frequently employed, but until recently had not been utilized long enough to assess final outcomes.

METHODS

GPI "graduates" with multi-level congenital curves were identified. Graduation was defined as a final fusion or 5 years of follow-up without planned future surgeries. Outcomes included radiographic parameters and complications.

RESULTS

26 patients were included. 11 had associated diagnoses; eight had fused ribs. 17 were treated with traditional growing rods, seven with vertically expandable prosthetic ribs, and two with Shilla procedures. The mean GPI spanned 12.3 levels including 10.7 motion segments, age at index surgery was 5.5 years, treatment spanned 7.5 years, and follow-up was 9.2 years. 24 patients underwent final fusion. Mean major curve decreased from 73° to 49° with index surgery (p < 0.01) and remained unchanged through a final follow-up. Final major curve was < 40° in 9 patients (35%), 40°-60° in 11 patients (42%), and > 60° in 6 patients (23%). None worsened throughout treatment. Mean T1-T12 height increased 2.4 cm with index surgery (p = 0.02) and 5.4 cm total (p < 0.01). T1-T12 height increased in all patients and was ultimately < 18 cm in 10 patients (38%), 18-22 cm in 10 patients (38%), and > 22 cm in 6 patients (23%). On average, there were 2.6 complications per patient, including 1.7 implant failures. 12 patients (46%) experienced ≥ 3 complications; four patients (15%) experienced none.

CONCLUSION

We observed successful prevention of deformity progression but substantial residual deformity among GPI graduates with multi-level congenital EOS. Most coronal curve correction was attained during GPI implantation; thoracic height improved throughout treatment. While some favorable results were found, treatment strategies allowing improved deformity correction would be valuable for this challenging population.

LEVEL OF EVIDENCE

Therapeutic-III.

Intrathecal Morphine in the Presence of a Syrinx in Pediatric Spinal Deformity Surgery

BACKGROUND

Intrathecal morphine (IM) is a popular adjunct for pain relief during pediatric spinal deformity surgery. There is no literature regarding its usefulness and safety in the presence of a spinal cord syrinx for patients undergoing spinal instrumentation. Anesthesiologists have previously been reluctant to use IM in the presence of any syrinx.

METHODS

We retrospectively reviewed all patients with a preoperatively diagnosed spinal cord syrinx undergoing spinal deformity surgery who received IM and did not receive IM (non-IM). We recorded location of the syrinx, surgical time, length of stay, unexpected pediatric intensive care unit (PICU) admission, IM related complications (neurological, respiratory depression, or pruritus, nausea/vomiting), and reason for no IM administration. Patients with a syrinx and myelodysplasia (8), tethered spinal cord (4), paraplegia (1), holocord (1), neuroblastoma (1), and spinal cord glioma (1) were not given IM. Other reasons included a failed attempt (1), expectedly short surgical time (1), and anesthesiologist declined (2).

RESULTS

There were 42 patients who met the inclusion criteria. Twenty-two patients received IM, while 20 patients did not. Patients receiving IM had 4 cervical, 5 cervicothoracic, 12 thoracic syrinxes, and 1 holocord syrinx. The non-IM group had 8 cervicothoracic, 6 thoracic, 4 holocord syrinxes, and 2 had unclassified locations. There were no neurological complications in the IM group, and 1 patient experienced respiratory depression following a shorter than expected surgery and was observed overnight in the PICU. One patient in the non-IM group with a holocord syrinx had temporary lower extremity weakness postoperatively that completely resolved and 4 patients were unexpectedly admitted to the PICU. Pruritus and nausea/vomiting was mild and similar in both groups.

CONCLUSIONS

Our study demonstrates that with careful preoperative evaluation, most patients with a spinal cord syrinx can safely be given IM. Certain patients, such as those with a spinal holocord syrinx may have anatomic reasons to avoid IM, but those who are deemed appropriate for IM can receive it safely.

LEVEL OF EVIDENCE

Level III-therapeutic study; retrospective comparative study.

Results of growth-friendly management of early-onset scoliosis in children with and without skeletal dysplasias

Aims

The aim of this study was to compare the surgical and quality-of-life outcomes of children with skeletal dysplasia to those in children with idiopathic early-onset scoliosis (EOS) undergoing growth-friendly management.

Patients and Methods

A retrospective review of two prospective multicentre EOS databases identified 33 children with skeletal dysplasia and EOS (major curve ≥ 30°) who were treated with growth-friendly instrumentation at younger than ten years of age, had a minimum two years of postoperative follow-up, and had undergone three or more lengthening procedures. From the same registries, 33 matched controls with idiopathic EOS were identified. A total of 20 children in both groups were treated with growing rods and 13 children were treated with vertical expandable prosthetic titanium rib (VEPTR) instrumentation.

Results

Mean preoperative major curves were 76° (34° to 115°) in the skeletal dysplasia group and 75° (51° to 113°) in the idiopathic group (p = 0.55), which were corrected at final follow-up to 49° (13° to 113°) and 46° (12° to 112°; p = 0.68), respectively. T1-S1 height increased by a mean of 36 mm (0 to 105) in the skeletal dysplasia group and 38 mm (7 to 104) in the idiopathic group at the index surgery (p = 0.40), and by 21 mm (1 to 68) and 46 mm (7 to 157), respectively, during the distraction period (p = 0.0085). The skeletal dysplasia group had significantly worse scores in the physical function, daily living, financial impact, and parent satisfaction preoperatively, as well as on financial impact and child satisfaction at final follow-up, than the idiopathic group (all p < 0.05). The domains of the 24-Item Early-Onset Scoliosis Questionnaire (EOSQ24) remained at the same level from preoperative to final follow-up in the skeletal dysplasia group (all p > 0.10).

Conclusion

Children with skeletal dysplasia gained significantly less spinal growth during growth-friendly management of their EOS and their health-related quality of life was significantly lower both preoperatively and at final follow-up than in children with idiopathic EOS. Cite this article: Bone Joint J 2019;101-B:1563–1569

Superior Mesenteric Artery Syndrome Complicated by Gastric Mucosal Necrosis Following Congenital Scoliosis Surgery: A Case Report

CASE

This is a report of severe superior mesenteric artery (SMA) syndrome in an 11-year-old girl with congenital scoliosis following posterior spinal fusion and segmental spinal instrumentation. This was complicated by gastric mucosal necrosis but resolved satisfactory with prolonged nasogastric suction, intravenous fluids, and total parental nutrition.

CONCLUSIONS

All pediatric spine surgeons should be aware of SMA syndrome following spine surgery. This case demonstrates that although rare, significant complications such as gastric mucosal necrosis can occur. When present, it can be treated successfully with prolonged conservative management. Comanagement with pediatric gastroenterology and pediatric general surgery is recommended.

Risk Factors for Early Infection in Pediatric Spinal Deformity Surgery: A Multivariate Analysis

STUDY DESIGN

Retrospective case-control study.

OBJECTIVES

To identify risk factors for early deep surgical site infections (SSIs; within three months of index procedure) following pediatric spinal deformity surgery.

BACKGROUND

Deep surgical site infections (SSIs) following pediatric spinal deformity surgery are a source of significant morbidity. We sought to identify independent risk factors for early infection following primary, definitive single-stage pediatric posterior spinal fusion and instrumentation (PSFI).

METHODS

A total of 616 consecutive patients (2001-2016) from an institutional prospectively maintained Pediatric Orthopaedic Spine database were identified that met inclusion criteria of definitive single-stage PSFI. Early deep SSI was defined as infection within three months of index procedure requiring surgical intervention. A multivariate analysis of demographics, comorbidities, and perioperative factors was performed and independent risk factors were identified.

RESULTS

Eleven patients (1.6%) developed an early deep SSI. Independent risk factors for SSI identified were nonidiopathic (neuromuscular, syndromic, and congenital) etiologies of scoliosis (adjusted odds ratio [aOR]: 8.384, 95% confidence interval [CI]: 1.784-39.386, p = .007) and amount of intraoperative crystalloids (aOR: 1.547 per additional liter of fluid, 95% CI: 1.057-2.263, p = .025). Mean crystalloid administered in the SSI group was 3.3 ± 1.2 L versus 2.4 ± 1.0 L in the noninfected group (p = .019). On univariate analysis, there was no significant difference in weight of patients between cohorts (p = .869) or surgery time (p = .089). There was also no significant difference in infection rates from redosing of antibiotics intraoperatively after 3 hours of surgery (p = .231).

CONCLUSIONS

Nonidiopathic scoliosis and amount of intraoperative crystalloids were independently associated with early postoperative SSI. Further investigation into intraoperative fluid management may identify modifiable risk factors for early postoperative SSI in primary pediatric spinal deformity posterior spinal fusion patients.

LEVEL OF EVIDENCE

Level III, case-control study.

Growth-Friendly Surgery Is Effective at Treating Early-Onset Scoliosis Associated With Goldenhar Syndrome

OBJECTIVE

To evaluate the radiographic results and complications of growth-friendly (GF) surgery in the treatment of early-onset scoliosis (EOS) associated with Goldenhar syndrome.

BACKGROUND

Goldenhar syndrome has been associated with spinal deformity, which may be progressive. Efficacy and complication rate of GF treatment has not been reported for this population of patients with EOS.

METHODS

Patients with Goldenhar syndrome and EOS with two years' follow-up were identified from two international multicenter EOS databases. Scoliosis, kyphosis, spine height, and hemithoracic height/width were determined preimplant, immediately postoperative, and at the two-year follow-up. Severity of complications (SV) was recorded (Smith et al. JPO 2015).

RESULTS

Ten patients met inclusion criteria and had a mean age of 4.6 ± 2.5 years at GF implantation (one spine and nine rib-based). Mean preoperative scoliosis was 64°, postimplant 52°, and at mean follow up of 2.4 ± 0.5 years was 50° (p = .09). Preoperative kyphosis was 36°, postimplant 38°, and final 42° (p = .08). Preoperative T1-S1 height was 23.5 cm, postimplant 23.6 cm, and final 27.3 cm (p = .06). Preoperative convex hemithoracic height was 10.4 cm, postimplant 7.9 cm, and final 12.8 cm (p < .05). Preoperative concave hemithoracic height was 8.4 cm, postimplant 8.8 cm, and final 9.9 cm (p = .30). Preoperative right hemithoracic width was 8.02 cm, postimplant 7.22 cm, and final 7.86 cm (p = .07). Preoperative left hemithoracic width was 7.18 cm, postimplant 7.86 cm, and final 8.60 cm (p = .43). Eight patients had ≥1 complication with SV I (n = 7), SV II (n = 2), and SV IIA (n = 7). These included infection (n = 4), migration (n = 3), pneumonia (n = 2), and instrumentation failure (n = 2).

CONCLUSION

At minimum two-year follow-up, GF surgical intervention for the treatment of EOS associated with Goldenhar syndrome trended toward improvements in scoliosis and spine height, but had a significant improvement in convex hemithoracic height; however, the majority of patients experienced severity grade I or II complications.

LEVEL OF EVIDENCE

Level IV.

Outcomes of growing rod surgery for severe compared with moderate early-onset scoliosis: a matched comparative study

Aims

The aim of this study was to compare the outcomes of surgery using growing rods in patients with severe versus moderate early-onset scoliosis (EOS).

Patients and Methods

A review of a multicentre EOS database identified 107 children with severe EOS (major curve ≥ 90°) treated with growing rods before the age of ten years with a minimum follow-up of two years and three or more lengthening procedures. From the same database, 107 matched controls with moderate EOS were identified.

Results

The mean preoperative major curve was 101° (90 to 139) in the severe group and 67° (33° to 88°) in the moderate group (p < 0.001), which was corrected at final follow-up to 57° (10° to 96°) in the severe group and 40° (3° to 85°) in the moderate group (p < 0.001). T1-S1 height increased by a mean of 54 mm (-8 to 131) in the severe group and 27 mm (-4 to 131) in the moderate group at the initial surgery (p < 0.001), and by 50 mm (-17 to 200) and 54 mm (-11 to 212), respectively, during distraction (p = 0.84). The mean number of complications per patient was 2.6 (0 to 14) in the severe group and 1.9 (0 to 10) in the moderate group (p = 0.040). Five patients (4.7%) in the severe group and three (2.8%) in the moderate group developed a neurological deficit postoperatively (p = 0.47).

Conclusion

Severe EOS can be treated effectively using growing rods, but the risk of complications is high. Cite this article: Bone Joint J 2018;100-B:772-9.

Does Vancomycin Powder Decrease Surgical Site Infections in Growing Spine Surgery?: A Preliminary Study

BACKGROUND

Vancomycin powder has been demonstrated to be safe in children, and yet there are no data on its use to reduce surgical site infections (SSIs) in surgery for early-onset scoliosis.

METHODS

We performed a retrospective study of our patients treated for early-onset scoliosis in the period of 2010 to 2016. In 2010, we updated our standardized perioperative growing spine care path. The only later change was the gradual introduction of intrawound vancomycin powder. Procedures were categorized into either the control group (without vancomycin powder) or the experimental group (with vancomycin powder), with otherwise identical perioperative management. Initial insertion, revision, and lengthening procedures and final fusions were included. We compared the rate of postoperative SSIs per procedure between the groups.

RESULTS

Thirty-six patients who underwent 191 procedures met the inclusion criteria. The clinical and radiographic data were essentially the same between the groups. During the study period, 14 (39%) of the 36 patients developed ≥1 deep SSI. Only 2 patients had multiple acute infections. There were 87 procedures with 12 infections in the control group (SSI rate of 13.8% per procedure), while there were 104 procedures with 5 infections in the vancomycin group (4.8% per procedure). The difference in the SSI rate per procedure was significant (p = 0.038). The number of individual procedures needed to be performed using vancomycin to prevent an SSI was 10.9.

CONCLUSIONS

The use of vancomycin powder in growing spine surgery for early-onset scoliosis is associated with a significant decreased risk of SSI. It appears to be effective even when previous surgeries have been performed without its use.

LEVEL OF EVIDENCE

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

Radiographic Outcomes of Shilla Growth Guidance System and Traditional Growing Rods Through Definitive Treatment

STUDY DESIGN

Retrospective review of a multicenter database.

OBJECTIVES

To compare the radiographic outcomes of patients who had undergone the Shilla Growth Guidance System (SGGS) and traditional growing rod (GR) treatment for management of early-onset scoliosis (EOS) through definitive treatment.

SUMMARY OF BACKGROUND DATA

The efficacy of surgical treatment of EOS can only be determined after definitive treatment has been completed. We wanted to review our experience with the SGGS and GR for management of EOS through definitive treatment.

METHODS

Patients who had surgical treatment with SGGS or GR and had undergone definitive treatment were included. The patients were matched by age, preoperative curve magnitude, and diagnosis. The study population consisted of 36 patients (18 in each group) whose mean age at initial surgery was as follows: SGGS, 7.9 years; and GR, 7.7 years (not significant [NS]). Length of follow-up after initial surgery was 6.1 years for SGGS and 7.4 years for GR (NS). Definitive treatment was posterior spinal fusion (15 SGGS, 17 GR), implant removal (3 SGGS), or completion of lengthenings (1 GR).

RESULTS

The preoperative curve was 61 degrees for SGGS and 65 degrees for GR (NS). After index surgery, the major curve decreased to 24 degrees (-37 degrees) for SGGS and 38 (-27 degrees) for GR (p < .05). At last follow-up, the major curve was 34 degrees (44%) for SGGS and 36 degrees (45%) for GR (NS). The initial T1-T12 length for SGGS was 188 mm and for GR, 181 mm; at last follow-up, SGGS was 234 mm (46 mm increase) and GR was 233 mm (52 mm increase) (NS).

CONCLUSION

Our analysis shows the final radiographic outcomes (and changes) and complications (implant-related and infection) between the SGGS and GR groups were not statistically different. The main difference between the two groups was the threefold difference in overall surgeries.

Final Fusion After Growing-Rod Treatment for Early Onset Scoliosis: Is It Really Final?

BACKGROUND

Final fusion is thought to be the end point for patients with early onset scoliosis following treatment with the use of growing rods. But is it? The purpose of this study was to determine the incidence and cause of any reoperation after final fusion.

METHODS

A multicenter database of patients with early onset scoliosis was retrospectively analyzed to identify patients treated with growing rods with a minimum of 2 years of follow-up after final fusion. All reoperations were recorded. Reoperation was defined as a return to the operating room for any complication related to the final fusion surgery or etiology of the spinal deformity.

RESULTS

One hundred (84%) of 119 patients met the inclusion criteria: for 38 of the patients, the etiology of scoliosis was neuromuscular; for 31, syndromic; for 22, idiopathic; and for 9, congenital. The mean age at final fusion was 12.2 years (range, 8.5 to 18.7 years). The mean follow-up after final fusion was 4.3 years (range, 2 to 11.2 years). Twenty (20%) of the patients had 30 complications requiring reoperation (57 procedures). There was a mean of 1.5 complications per patient after final fusion. Eight patients with neuromuscular scoliosis, 8 with syndromic, 4 with idiopathic, and no patient with congenital scoliosis required reoperation. Nine (9%) of the patients experienced infection (33 reoperation procedures); 6 (6%) had instrumentation failure (8 procedures); 5 (5%) had painful or prominent instrumentation (6 procedures); 3 (3%) each had coronal deformity (3 procedures), pseudarthrosis (3 procedures), or sagittal deformity (3 procedures); and 1 (1%) had progressive crankshaft chest wall deformity requiring a thoracoplasty (1 procedure).

CONCLUSIONS

A higher-than-anticipated percentage of patients treated with growing rods required unplanned reoperation following final fusion. Long-term follow-up after final fusion is necessary to determine true final results. Patients and parents need to be counseled regarding the possibility of further surgery after final fusion.

LEVEL OF EVIDENCE

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

Age at Initiation and Deformity Magnitude Influence Complication Rates of Surgical Treatment With Traditional Growing Rods in Early-Onset Scoliosis

STUDY DESIGN

Multi-center retrospective review.

OBJECTIVE

The purpose of this study was to identify preoperative variables associated with postoperative complications in early-onset scoliosis (EOS) patients treated with traditional growing rods (TGR); and to develop a model to predict the incidence of postoperative complications based on preoperative variables.

SUMMARY OF BACKGROUND DATA

TGRs are commonly used to treat progressive EOS. Prior research has demonstrated a high rate of postoperative complications using this technique; however, few studies have identified preoperative factors that contribute to such complications.

METHODS

A total of 110 patients who initiated TGR treatment before 10 years of age and completed final treatment were identified from a multi-center database. Overall treatment effect was calculated for major curve size, thoracic kyphosis, thoracic height, and total spine height. Univariable and multivariable logistic regression identified preoperative predictors of complications. An algorithm was developed and validated to calculate the probability of complications based on preoperative data.

RESULTS

All patients completed TGR treatment (average follow-up 8.1 years). The overall treatment effect was a significant decrease in major curve magnitude, increase in thoracic height, increase in spine height, and no significant change in thoracic kyphosis. There were 263 total complications in 87 patients (79%) resulting in 84 unplanned surgeries. The most common complications were implant-related (49%), surgical site infection (23%), medical (19%), alignment (6%), and neurologic (3%). The significant independent preoperative predictors of complications were age at implantation and preoperative thoracic kyphosis. Multivariable regression showed that age less than 7.6 years, thoracic kyphosis greater than 38 degrees, or major curve magnitude greater than 84 degrees significantly increased the probability of complications.

CONCLUSIONS

Earlier age at implantation, greater thoracic kyphosis, and larger major curves increased the probability of complications following TGR instrumentation. These findings provide a valuable tool for predicting complications that may aid in surgical planning and shared decision making with patients and their families.

LEVEL OF EVIDENCE

IV.

Avoidance of "Final" Surgical Fusion After Growing-Rod Treatment for Early-Onset Scoliosis

BACKGROUND

Definitive "final" surgical fusion is the common end point for growing-rod treatment of early-onset scoliosis. However, final surgical fusion may be unnecessary for patients who have reached skeletal maturity with good alignment. This study characterizes patients who completed growing-rod treatment but did not undergo final surgical fusion.

METHODS

Using a multicenter early-onset-scoliosis database, we identified 167 patients who received growing-rod treatment from 1995 through 2010, reached skeletal maturity, and had a minimum 2-year follow-up after their last surgery. Thirty patients did not undergo final surgical fusion (observation group) and were compared clinically and radiographically with 137 patients who did undergo final fusion (final surgical fusion group).

RESULTS

No significant differences were found between the groups with regard to the age at which treatment was initiated (p = 0.127), distribution of diagnoses (p = 0.84), or number of lengthening procedures (p = 0.692). In the observation group, 26 patients retained the growing rods and 4 patients had them removed at the last surgery because of infection. The mean primary curve correction at the end of treatment was 48% (from an initial mean magnitude of 79° to a mean final curve of 41°) in the observation group compared with 38% (from 74° to 46°) in the final surgical fusion group. There was no significant difference in final curve magnitude (41° in the observation group and 46° in the final surgical fusion group; p = 0.182). The mean increase in trunk height was 30.5% in the observation group and 35% in the final surgical fusion group. The final trunk height in the observation group was not significantly less than that in the final surgical fusion group (p = 0.142).

CONCLUSIONS

Because of progressive ankylosis, avoiding final surgical fusion at skeletal maturity is a viable option for patients treated with growing rods for all diagnostic subgroups of early-onset scoliosis who have satisfactory final alignment and trunk height, a minimal gain in length at the last distraction, and no clinical or radiographic evidence of implant-related problems.

LEVEL OF EVIDENCE

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

Outcomes of Pelvic Fixation in Growing Rod Constructs: An Analysis of Patients With a Minimum of 4 Years of Follow-up

STUDY DESIGN

Retrospective review.

OBJECTIVE

To evaluate which distal anchors in growing rod (GR) constructs optimally correct major curve, pelvic obliquity, sagittal alignment, T1-S1 length, thoracic kyphosis, and lumbar lordosis with the fewest complications at 4 or more years' postoperative follow-up.

SUMMARY OF BACKGROUND DATA

Pelvic fixation to the ilium and/or sacrum in GR constructs is used to treat patients with early-onset scoliosis. No studies have evaluated radiographical outcomes and complications in these patients at 4 or more years' follow-up.

METHODS

Included were 38 patients from a multicenter early-onset-scoliosis database with dual GRs anchored to the pelvis. Radiographic data included major curve, T1-S1 length, T5-T12 kyphosis, lordosis, sagittal alignment, and pelvic obliquity at preoperative and latest follow-up time points. Complications were evaluated for all anchor subtypes.

RESULTS

Mean follow-up time was 5.3 ± 0.1 years. GRs with distal anchors to the ilium significantly improved major curve (49%, p = .013) and pelvic obliquity (78%, p = .035) compared with constructs anchored to the sacrum only. Constructs with iliac fixation with S1 screws provided greater correction of lumbar kyphosis than constructs with iliac fixation and no S1 screws (p = .023). Constructs with a single caudal crosslink had a greater T1-S1 length at latest follow-up than constructs with combined cephalad and caudal crosslinks (p = .027). There were no significant differences in the rates of infection or instrumentation failure between iliac and sacral fixation groups. GR constructs with distal anchors that used a posterior superior iliac spine start point had a higher infection rate (60%) than those inserted via a sacral-alar-iliac technique (7%) (p = .002).

CONCLUSIONS

GR constructs anchored to the ilium provide significant improvements in the major curve and pelvic obliquity at a minimum of 4 years of follow-up versus constructs anchored to the sacrum alone.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Intrathecal morphine attenuates acute opioid tolerance secondary to remifentanil infusions during spinal surgery in adolescents

Introduction

The unique pharmacokinetic properties of remifentanil with a context-sensitive half-life unaffected by length of infusion contribute to its frequent use during anesthetic management during posterior spinal fusion in children and adolescents. However, its intraoperative administration can lead to increased postoperative analgesic requirements, which is postulated to be the result of acute opioid tolerance with enhancement of spinal N-methyl-D-aspartate receptor function. Although strategies to prevent or reduce tolerance have included the coadministration of longer acting opioids or ketamine, the majority of these studies have demonstrated little to no benefit. The current study retrospectively evaluates the efficacy of intrathecal morphine (ITM) in preventing hyperalgesia following a remifentanil infusion.

Methods

We retrospectively analyzed 54 patients undergoing posterior spinal fusion with segmental spinal instrumentation, to evaluate the effects of ITM on hyperalgesia from remifentanil. Patients were divided into two groups based on whether they did or did not receive remifentanil during the surgery: no remifentanil (control group) (n=27) and remifentanil (study group) (n=27). Data included demographics, remifentanil dose and duration, Wong–Baker visual analog scale postoperative pain scores, and postoperative intravenous morphine consumption in the first 48 postoperative hours.

Results

The demographics of the two study groups were similar. There were no differences in the Wong–Baker visual analog scale pain scores in the postanesthesia care unit and on postoperative days 1 and 3. Pain scores were higher in the remifentanil group on postoperative day 2 (2.9 vs 3.8). Postoperative morphine requirements were similar between the two groups (0.029 vs 0.017 mg/kg/48 h for the control group and the study group, respectively).

Conclusion

In patients receiving preincisional ITM during spinal surgery, intraoperative remifentanil does not increase postoperative analgesic requirements.

Is There an Optimal Time to Distract Dual Growing Rods?

STUDY DESIGN

Retrospective multicenter observational cohort study.

OBJECTIVES

To determine whether there is a significant difference in final spinal height achieved, instrumented height, or Cobb angle related to the mean time interval between distractions of dual growing rods.

SUMMARY OF BACKGROUND DATA

Patients were prospectively enrolled in "The Treatment of Progressive Early Onset Spinal Deformities: A Multi-Center Study." Additional data were collected via a retrospective review of medical records.

METHODS

Using data from a multicenter database, the authors identified 46 patients (23 boys and 23 girls) with early-onset scoliosis who were treated with dual growing rods and who had surgical treatment spanning more than 4 years. The patients were divided into 2 groups: those who had less than 9 months (16 patients) and those who had 9 months or more (30 patients) between distractions. Standard univariate statistics were calculated. The researchers performed 2-tailed t tests. Significance was set at p = .05.

RESULTS

The differences in primary Cobb angle, T1-S1 height, and instrumented segment length at the last distraction or final arthrodesis, compared with the post-index procedure values, were not significantly different (p = .52, .58, and .60, respectively) between groups with the available data. The normalized instrumented height gains, in millimeters per year, were not significantly different (p = .22).

CONCLUSIONS

Patients with longer times between growing-rod distractions (9 or more months) had no significant differences in primary Cobb angle, T1-S1 length, or instrumented length gain compared with patients with shorter times (less than 9 months) between distractions.

Traditional Growing Rods Versus Magnetically Controlled Growing Rods for the Surgical Treatment of Early-Onset Scoliosis: A Case-Matched 2-Year Study

INTRODUCTION

Traditional growing rod (TGR) surgery is a treatment technique commonly used for progressive early-onset scoliosis. Studies have shown that repeated TGR lengthenings can significantly increase the risk of complications. Magnetically controlled growing rods (MCGR) are currently available outside of the United States and early results have been promising. The purpose of this study was to compare the effectiveness of MCGR versus TGR for the treatment of early-onset scoliosis.

METHODS

Magnetically controlled growing rod patients were selected based on the following criteria: aged less than 10 years, major curve greater than 30°, thoracic height less than 22 cm, no previous spine surgery, and minimum 2-year follow-up. A total of 17 MCGR patients met the inclusion criteria, 12 of whom had complete data available for analysis. Each MCGR patient was matched with a TGR patient by etiology, gender, single versus dual rods, preoperative age, and preoperative major curve.

RESULTS

Magnetically controlled growing rod patients had a mean age of 6.8 years and mean follow-up of 2.5 years. Mean follow-up was greater for TGR patients by 1.6 years. Major curve correction was similar between MCGR and TGR patients throughout treatment. The MCGR patients experienced an average of 8.1 mm/year increase in T1-S1 during the lengthening period, compared with 9.7 mm/year for TGR patients (p = .73). There was a mean increase in T1-T12 of 1.5 mm/year for MCGR patients and 2.3 mm/year for TGR patients (p = .83). The TGR patients had 73 open surgeries, 56 of which were lengthenings. The MCGR patients had 16 open surgeries and 137 noninvasive lengthenings. Three TGR patients underwent 5 unplanned revision surgeries whereas 3 MCGR patients underwent 4 unplanned revisions.

CONCLUSIONS

Major curve correction was similar between MCGR and TGR patients throughout treatment. Annual T1-S1 and T1-12 growth was also similar between groups. The MCGR patients had 57 fewer surgical procedures than TGR patients. Incidence of unplanned surgical revisions as a result of complications was similar between groups.

Do Thoracolumbar/lumbar Curves Respond Differently to Growing Rod Surgery Compared With Thoracic Curves?

STUDY DESIGN

Retrospective study.

OBJECTIVES

To compare radiographic outcomes between primary thoracic and primary thoracolumbar/lumbar curves in patients with early-onset scoliosis (EOS) after growing rod (GR) surgery.

SUMMARY OF BACKGROUND DATA

Previous studies have shown the efficacy of GR surgery for progressive EOS. However, there is no information on the behavior of different curve patterns in EOS after GR surgery.

METHODS

A multicenter international EOS database query identified 175 patients who met the following inclusion criteria: non-congenital etiology, GR surgery, ≤ 10 years of age at index surgery, minimum 2-year follow-up, and at least 3 lengthenings. Patients were categorized into 2 groups based on the Scoliosis Research Society definition of the anatomical location of primary curves: group 1 included thoracic apices (T2 to T11/12 disc) and group 2 included thoracolumbar (T12 to L1) and lumbar (L1/2 disc to L4) apices. Radiographic measurements were performed before and after index surgery and at latest follow-up.

RESULTS

A total of 139 patients (79%) had primary thoracic (group 1) and 36 (21%) had primary thoracolumbar or lumbar curves (group 2). Mean number of levels instrumented was statistically greater in group 2 (15.0) versus group 1 (13.6) (p < .05). Group 2 had statistically better mean curve correction than group 1 after the index GR surgery (51% and 44%, respectively; p < .05). However, there was no significant difference in mean percent curve correction at latest follow-up (46% and 39%, respectively; p > .05). Implant complication rate was 45% and 47% for groups 1 and 2, respectively. Preoperative curve flexibility was greater in group 2 (45%) compared with group 1 (40%) (p > .05).

CONCLUSIONS

Overall, thoracolumbar/lumbar and thoracic curves achieve similar major curve correction and have a similar complication profile.

Development and initial validation of the Classification of Early-Onset Scoliosis (C-EOS)

BACKGROUND

Early-onset scoliosis is a heterogeneous condition, with highly variable manifestations and natural history. No standardized classification system exists to describe and group patients, to guide optimal care, or to prognosticate outcomes within this population. A classification system for early-onset scoliosis is thus a necessary prerequisite to the timely evolution of care of these patients.

METHODS

Fifteen experienced surgeons participated in a nominal group technique designed to achieve a consensus-based classification system for early-onset scoliosis. A comprehensive list of factors important in managing early-onset scoliosis was generated using a standardized literature review, semi-structured interviews, and open forum discussion. Three group meetings and two rounds of surveying guided the selection of classification components, subgroupings, and cut-points. Initial validation of the system was conducted using an interobserver reliability assessment based on the classification of a series of thirty cases.

RESULTS

Nominal group technique was used to identify three core variables (major curve angle, etiology, and kyphosis) with high group content validity scores. Age and curve progression ranked slightly lower. Participants evaluated the cases of thirty patients with early-onset scoliosis for reliability testing. The mean kappa value for etiology (0.64) was substantial, while the mean kappa values for major curve angle (0.95) and kyphosis (0.93) indicated almost perfect agreement. The final classification consisted of a continuous age prefix, etiology (congenital or structural, neuromuscular, syndromic, and idiopathic), major curve angle (1, 2, 3, or 4), and kyphosis (-, N, or +) variables, and an optional progression modifier (P0, P1, or P2).

CONCLUSIONS

Utilizing formal consensus-building methods in a large group of surgeons experienced in treating early-onset scoliosis, a novel classification system for early-onset scoliosis was developed with all core components demonstrating substantial to excellent interobserver reliability. This classification system will serve as a foundation to guide ongoing research efforts and standardize communication in the clinical setting.

Deep Surgical Site Infection Following 2344 Growing-Rod Procedures for Early-Onset Scoliosis: Risk Factors and Clinical Consequences

BACKGROUND

Deep surgical site infection may change the course of growing-rod treatment of early-onset scoliosis. Our goal was to assess the effect of this complication on subsequent treatment.

METHODS

A multicenter international database was retrospectively reviewed; 379 patients treated with growing-rod surgery and followed for a minimum of two years were identified. Deep surgical site infection was defined as any infection requiring surgical intervention.

RESULTS

Forty-two patients (11.1%; twenty-five males and seventeen females) developed at least one deep surgical site infection. The mean age at the initial growing-rod surgery was 6.3 years (range, 0.6 to 13.2 years) and the mean duration of follow-up was 5.3 years (range, 2.2 to 14.3 years). The mean interval between the initial surgery and the first deep surgical site infection was 2.8 years (range, 0.02 to 7.9 years). Ten (2.6%) of the 379 patients developed deep surgical site infection before the first lengthening. Twenty-nine patients (7.7%) developed the infection during the course of the lengthening procedures, and three patients (0.8%) developed it after final fusion surgery. Thirty (13.6%) of 221 patients with stainless-steel implants had at least one deep surgical site infection compared with twelve (8%) of 150 patients with titanium implants (p < 0.05). (The remaining patients were treated with chromium-cobalt implants.) Twenty-two (52.4%) of the forty-two patients with deep surgical site infection underwent implant removal, which was complete in thirteen and partial in nine. Growing-rod treatment was terminated in two patients with partial removal and six patients with complete removal. An increased risk of deep surgical site infection was associated with stainless-steel implants (odds ratio [OR] = 5.7), non-ambulatory status (OR = 2.9), and the number of revisions before the development of deep surgical site infection (OR = 3.3). Neuromuscular etiology and non-ambulatory status increased the possibility of implant removal to treat infection (p < 0.05).

CONCLUSIONS

The prevalence of deep surgical site infection associated with growing-rod surgery is higher than that associated with standard pediatric spinal fusion (historical data). Non-ambulatory status, more revisions, and stainless-steel implants increased the risk of deep surgical site infection. After eight surgical procedures, the risk of deep surgical site infection increased to approximately 50%. When patients have implant removal, efforts should be made to retain one longitudinal implant to continue treatment.

LEVEL OF EVIDENCE

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

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

PURPOSE

We aimed to evaluate the nutritional status of children with early onset scoliosis (EOS) and to determine if treatment with growing rod instrumentation improves weight percentile.

METHODS

Data was retrospectively collected on 88 EOS patients treated with growing rods at six institutions. Mean age at surgery was 5.8 years, and mean Cobb angle was 75°. All patients were followed for at least 2 years (mean 4 years). Weights were converted to normative percentiles based on the patients' age and gender.

RESULTS

Preoperatively, 47 % (41/88) of patients were <5 percentile for weight, thus failing to thrive. There was a significant increase in mean postoperative weight percentiles at latest follow-up (p = 0.004). 49 % of patients gained weight, with a mean of 18 percentile. A significant relationship exists between age at initial surgery and percentile weight gain (p < 0.005), with children <4 years old not demonstrating postoperative improvement. This relationship was not confounded by preoperative weight, preoperative Cobb angle, or years of follow-up (p > 0.05). Children with neuromuscular and syndromic diagnoses do not appear to improve their mean nutritional status after surgery when compared to patients with idiopathic or congenital/structural scoliosis (p = 0.006).

CONCLUSION

Following growing rod treatment, there was significant improvement in nutritional status in approximately 50 % of patients, similar to that reported with VEPTR. Neuromuscular and syndromic patients did not experience nutritional improvement post-operatively. These findings support the theory that growing rods improve the clinical status of EOS patients, as nutritional improvement is one outcome of improved clinical status. The relationship between age at initial surgery and nutritional improvement is intriguing.

Growing-rod graduates: lessons learned from ninety-nine patients who completed lengthening

BACKGROUND

Growing-rod spinal instrumentation systems are a valuable tool for managing severe early-onset scoliosis. There is little information about the end point of treatment.

METHODS

A multicenter early-onset-scoliosis database was searched to identify patients who had undergone treatment with growing rods and either had had a final operative procedure or were still being treated with the growing rods after reaching skeletal maturity (defined as fourteen years of age or older). Clinical, radiographic, and operative data were analyzed.

RESULTS

Ninety-nine patients met the inclusion criteria, and ninety-two (93%) of them had had a final operative procedure. The remaining seven patients (7%) were older than fourteen years but had not undergone a final procedure. Of the ninety-two patients who had a final procedure, seventy-nine (86%) had an instrumented fusion, nine (10%) had growing-rod exchanges and fusion in situ, three (3%) had the growing rods left in place and fusion in situ, and one (1%) had only growing-rod removal. The mean age (and standard deviation) at the final fusion was 12.4 ± 1.9 years. In forty-four (55%) of eighty patients for whom the information was available, the number of vertebral levels fused was the same as the number of vertebral levels spanned by the growing rods. The percent correction of the curve after final fusion was none or minimal (≤ 20 %) in eleven (18%) of the sixty-two patients for whom sufficient-quality radiographs were available, moderate (21% to 50%) in thirty (48%), and substantial (≥ 51 %) in nine (15%); the curve had worsened in twelve patients (19%). The mean duration of growing-rod treatment was 5.0 ± 2.6 years. Of fifty-eight operative reports made at final fusion that contained comments on spinal flexibility, eleven (19%) described the spine as being mobile, eleven (19%) described decreased flexibility, and thirty-six (62%) described the spine as being completely stiff. At final fusion, twenty-two patients (24%) had osteotomies and seven patients (8%) had a thoracoplasty.

CONCLUSIONS

Most patients underwent growing-rod removal and final instrumented fusion. The final fusion often included the same levels spanned by the growing rods and usually achieved <50% additional correction of the deformity remaining at the end of the growing-rod management.

LEVEL OF EVIDENCE

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