Surgery For Early-onset Scoliosis Research Articles

Evaluation of crankshaft phenomenon after posterior fusion for early onset scoliosis using an inverse trigonometric function: a multicenter retrospective cohort study.

The crankshaft phenomenon (CSP) is a corrective loss after posterior surgery for early onset scoliosis (EOS). However, an accurate method for CSP evaluation has yet to be developed. In this study, we evaluated pedicle screw (PS) length and rotation angle using an inverse trigonometric function and investigated the prevalence of the CSP. Fifty patients from nine institutions (mean age 10.6years, male/female ratio 4:46) who underwent early definitive fusion surgery at ≤ 11years of age were included. The rotation angle was calculated as arctan (lateral/frontal PS length) using radiography. Measurements were taken at the apex and lower instrumented vertebra (LIV) immediate, 2-, and 5-year postoperatively. CSP was defined as a rotation angle progression ≥ 5°. We divided patients into CSP and non-CSP groups and measured the demographic parameters, Risser grade, state of the triradiate cartilage, major coronal Cobb angle, T1-T12 length, T1-S1 length, and presence of distal adding-on (DAO). We compared these variables between groups and investigated the correlation between the measured variables and vertebral rotation. Logistic regression analysis investigated factors associated with CSP. The rotation angle progressed by 2.4 and 1.3° over 5years for the apex and LIV, respectively. CSP occurred in 15 cases (30%), DAO in 11 cases (22%), and CSP and DAO overlapped in 4 cases (8%). In the CSP group, the T1-T12 length was low immediate postoperatively. The rotation angle was negatively correlated with preoperative height (r = -0.33), T1-T12 length (r = -0.35), and T1-S1 length (r = -0.30). A lower preoperative T1-T12 length was associated with CSP (odds ratio: 0.996, p = 0.048). CSP occurred in 30% of patients with EOS who underwent definitive fusion. The presence of CSP was associated with a lower preoperative T1-T12 length. Diagnosis, level IV.

Autofusion in growing rod surgery for early onset scoliosis; what do we know so far?

The evolving landscape of early onset scoliosis management has shifted from the traditional paradigm of early definitive spinal fusion towards modern growth-friendly implants, particularly Growing Rods (GR). Despite the initial classification of GR treatment as a fusionless procedure, the phenomenon of autofusion has emerged as a critical consideration in understanding its outcomes. Studies have demonstrated the presence of autofusion since the early 1980s. The consequences of autofusion are extensive, impacting curve correction, diminishing trunk growth rate, and contributing to the "law of diminishing returns" in growing rod surgery. The literature suggests that autofusion may complicate definitive fusion surgery, leading to prolonged and intricate procedures involving multiple osteotomies. Additionally, it poses challenges in identifying anatomical landmarks during surgery, potentially increasing the risk of complications and revisions. While autofusion poses challenges to achieving optimal outcomes in growing rod treatment, it cannot be considered a standalone replacement for definitive fusion. Recent advances aim to limit autofusion and enhance treatment outcomes. In this review, we will delve into the existing literature on autofusion, examining studies that have documented its presence, probable causes, pathophysiology, potential implications for long-term patient outcomes, and possible new implants and techniques that decrease its incidence.

A Comparative Analysis of Revision Surgery Before or After 2 Years After Graduation From Growth-friendly Surgery for Early Onset Scoliosis

Introduction: After discontinuation of growth-friendly (GF) surgery for early onset scoliosis, patients are termed graduates: they undergo a spinal fusion, are observed after final lengthening with GF implant maintenance, or are observed after GF implant removal. The purpose of this study was to compare the rates of and reasons for revision surgery in two cohorts of GF graduates: before or after 2 years of follow-up from graduation. Methods: A pediatric spine registry was queried for patients who underwent GF spine surgery with a minimum of 2 years of follow-ups after graduation by clinical and/or radiographic evidence. Scoliosis etiology, graduation strategy, number of, and reasons for revision surgery were queried. Results: There were 834 patients with a minimum of 2-year follow-up after graduation who were analyzed. There were 241 (29%) congenital, 271 (33%) neuromuscular, 168 (20%) syndromic, and 154 (18%) idiopathic. 803 (96%) had traditional growing rod/vertical expandable titanium rib as their GF construct and 31 (4%) had magnetically controlled growing rod. Five hundred ninety-six patients (71%) underwent spinal fusion at graduation, 208 (25%) had GF implants retained, and 30 (4%) had GF implants removed. In the entire cohort, there were 108/834 (13%) patients who underwent revision surgery. Of the revisions, 71/108 (66%) occurred as acute revisions (ARs) between 0 and 2 years from graduation (mean 0.6 y), and the most common AR indication was infection (26/71, 37%). The remaining 37/108 (34%) patients underwent delayed revision (DR) surgery >2 years (mean 3.8 y) from graduation, and the most common DR indication was implant issues (17/37, 46%). Graduation strategy affected revision rates. Of the 596 patients with spinal fusion as a graduation strategy, 98/596 (16%) underwent revision, compared with only 8/208 (4%) patients who had their GF implants retained, and 2/30 (7%) that had their GF implants removed (P ≤ 0.001). A significantly higher percentage of the ARs had a spinal fusion as the graduation strategy (68/71, 96%) compared with 30/37 DRs, (81%, P = 0.015). In addition, the 71 patients who underwent AR undergo more revision surgeries (mean: 2, range: 1 to 7) than 37 patients who underwent DR (mean: 1, range: 1 to 2) (P = 0.001). Conclusion: In this largest reported series of GF graduates to date, the overall risk of revision was 13%. Patients who undergo a revision at any time, as well as ARs in particular, are more likely to have a spinal fusion as their graduation strategy. Patients who underwent AR, on average, undergo more revision surgeries than patients who underwent DR. Level of Evidence: Level III, comparative.

Safety and efficacy of intrathecal morphine in early onset scoliosis surgery.

Intrathecal morphine (IM) is a popular adjunct for pain management in spinal deformity surgery for idiopathic scoliosis. It has not been studied in patients with early onset scoliosis (EOS). We retrospectively reviewed EOS patients undergoing growth-friendly surgery who received IM or did not receive IM (non-IM). Data from initial insertion and final fusion procedures were studied. IM was not used for lengthening procedures, short procedures (<3 h), patients with significant underlying respiratory issues, paraplegia, unsuccessful access and anesthesiologist discretion. We assessed pediatric ICU (PICU) admission and IM complications (respiratory depression, pruritus and nausea/vomiting), time to first postoperative opiate, and pain scores. There were 97 patients including 97 initial insertions (26 IM and 71 non-IM) and 74 patients with final fusions (17 IM and 57 non-IM). The first dose of opioids following insertion and final fusion occurred at 16.8 ± 3.8 and 16.8 ± 3.1 h postoperatively in the IM group compared to 5.5 ± 2.8 and 8.3 ± 3.2 h in the non-IM group, respectively ( P < 0.001). Postoperative pain scores were lower in the IM groups ( P = 0.001). Two patients with IM developed mild respiratory depression following initial insertion ( P = 0.01) but did not require PICU admission. The rate of respiratory depression was not different between the final fusion groups. There was no difference between pruritus and nausea/vomiting at the final fusion. Preincision IM can provide well-tolerated and effective initial postoperative analgesia in select children with EOS undergoing spinal deformity surgery.

Complications in growth-friendly spinal surgeries for early-onset scoliosis: Literature review.

BACKGROUNDThe treatments for early-onset scoliosis (EOS), defined as curvature of the spine with onset before 10 years of age, continue to pose a great challenge for pediatric orthopedics. The treatment goals for EOS include minimizing spinal deformity while maximizing thoracic volume and pulmonary function. Different surgical techniques have different advantages and drawbacks; however, the two major concerns in the management of EOS are repeated surgeries and complications.AIMTo review the current literature to assess the safety of EOS surgical treatment in terms of the rate of complications and unplanned surgeries.METHODSIn January 2021 two independent reviewers systematically searched three electronic medical databases (PubMed, the Cochrane Library, and Embase) for relevant articles. Every step of the review was done according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Due to the heterogeneity of articles and topics after data analysis, a descriptive (synthetic) analysis was performed.RESULTSA total of 2136 articles were found. Forty articles were included in this systematic review, after applying our inclusion and exclusion criteria. EOS surgery has a varying but high rate of complications. The most frequent complications were categorized as implant (54%), general (17%), wound (15%) and alignment (12%). The rate of complications might have been even higher than reported, as some authors do not report all types of complications. About 54% of patients required unplanned surgeries due to complications, which comprised 15% of all surgeries.CONCLUSIONThe literature concerning the definitions, collection, and interpretation of data regarding EOS surgery complications is often difficult to interpret. This creates problems in the comparison, analysis, and improvement of spine surgery practice. Additionally, this observation indicates that data on the incidence of complications can be underestimated, and should be interpreted with caution. Awareness of the high rate of complications of EOS surgery is crucial, and an optimal strategy for prevention should become a priority.

The growth process after Growing-rod surgery for early onset scoliosis

The growth process after Growing-rod surgery for early onset scoliosis

Minimum 5-Year Follow-up on Graduates of Growing Spine Surgery for Early Onset Scoliosis.

After discontinuation of growth friendly (GF) surgery for early onset scoliosis, patients undergo spinal fusion or continued observation. This last planned treatment is colloquially called "definitive" treatment, conferring these patients as "graduates" of a growing program. The 5-year radiographic and clinical outcomes of this cohort are unknown. An international pediatric spine database was queried for patients from a GF program (spine or rib-based) with minimum 5-year follow-up from last planned surgery (GF or spinal fusion). Radiographs and charts were reviewed for main coronal curve angle and maximum kyphosis as well as occurrence of secondary surgery. Of 580 graduates, 170 (29%) had minimum 5-year follow-up (37% male). Scoliosis etiology was congenital in 41 (24%), idiopathic 36 (21%), neuromuscular 51 (30%), and syndromic 42 (25%). Index surgery consisted of spine-based growing rods in 122 (71%) and rib-based distraction in 48 (29%). Mean age at index surgery was 6.8 years, and patients underwent an average of 5.4 lengthenings over an average of 4.9 years (range, 6 mo to 11 y). Last planned treatment was at an average age of 11.8 years (range, 7 to 17 years). Last planned treatment consisted of spinal fusion in 114 patients, 47 had growing implants maintained, 9 had implants removed. Average follow-up was 7.3 years (range, 5 to 13 y).When compared from postdefinitive treatment to 2-year follow-up, there was noted progression of the coronal curve angle (46±19 to 51±21 degrees, P=0.046) and kyphosis (48±20 to 57±25 degrees, P=0.03). However, between 2 and 5 years, no further progression occurred in the coronal (51±21 to 53±21 degrees, P=0.26) or sagittal (57±25 to 54±28 degrees, P=0.93) planes. When stratified based on etiology, there was no significant coronal curve progression between 2- and 5-year follow-up. When comparing spinal fusion patients to those who had maintenance of their growing construct, there was also no significant curve progression.Thirty-seven (21%) underwent at least 1 (average, 1.7; range, 1 to 7) revision surgery following graduation, and 15 of 37 (41%) underwent 2 or more revision surgeries. Reason for revision was implant revision (either GF or spinal fusion) in 34 patients, and implant removal in 3. On an average, the first revision was 2.5 years after the definitive treatment plan (range, 0.02 to 7.4 y). In total, 15 of 37 (41%) revisions occurred over 2 years following the final decision for treatment plan, and 7 of 37 (19%) occurred 5 or more years after the definitive treatment.Patients who underwent spinal fusion as a definitive treatment strategy were more likely to undergo revision surgery (27%) than patients who had their GF implants maintained (11%) (P=0.04). Five years following "graduation" from growing surgery for early onset scoliosis, there is progression of curve magnitude in both the coronal and sagittal planes up to 2 years, with no further progression at 5 years. A total of 21% of patients undergo at least 1 revision surgery, and average time to revision surgery is over 2 years from last planned surgery. Risk of revision surgery was higher in patients who underwent a spinal fusion as their definitive treatment strategy. Level III-retrospective comparative. Therapeutic.

The Use of Metal Sublaminar Wires in Modern Growth-Guidance Scoliosis Surgery: A Report of 4 Cases and Literature Review

To avoid early fusion and allow residual growth of the spine in early onset scoliosis (EOS) treatment, growth-guided scoliosis surgery can be performed. Four patients with EOS are presented in which a growth-guidance instrumentation is used with sliding titanium (Ti) sublaminar cables. Residual growth of the spine can be preserved using metal sublaminar wiring; however, several drawbacks of this technique and type of material are illustrated. Four patients with progressive neuromuscular scoliosis were treated with a posterior stabilization. A fusionless growth-guidance instrumentation was used consisting of a combination of lumbar pedicle screws and sliding Ti sublaminar cables along cobalt chrome rods. In 2 cases, the described growth-guidance technique provided sufficient stability and correction of the curvature with preservation of growth. In 2 patients, the instrumentation failed due to upper thoracic sublaminar wire breakage. The ongoing abrasion of the rod-wire interface caused severe metallosis. In these cases, a debridement and revision surgery was performed with partial fusion of the spine. Growth-guidance techniques with sliding metal sublaminar wires seem to be a valuable solution for the preservation of spinal growth in EOS surgery. High curvatures, however, have a higher chance of failure and demand for more corrective strength and support of the instrumentation. The use of metal sublaminar wires in a "sliding" instrumentation can lead to early breakage and metallosis. 4, case series. Surgeons should be aware of possible complications associated with the use of metal laminar wires in spinal fusion and growth-guidance scoliosis surgery. The implementation of materials containing higher fatigue strength and lower friction properties (eg, UHMWPE wires) may avoid these potential complication risks.

Magnetically controlled growing rods in early onset scoliosis surgery: a review of Englishlanguage literature

The objective of the review is to provide multifaceted information on the treatment of young children with severe onset scoliosis using magnetically-controlled growing rods (MCGR). This promising though controversial method is not yet well known in our country. The review presents the history of the development of the method, surgical technique, the frequency of etiological forms of spinal deformities, and describes in detail the results of scoliosis correction including the most severe cases. Quantitative and qualitative data describe complications that arise during the treatment including those characteristic only for this method (for example, slippage phenomena). The problem of repeated operations is separately discussed, and the capabilities of MCGR and other techniques based on the principle of distraction are compared. The review presents features of the use of MCGR in adult patients, the dynamics of the primary curve in the postoperative period (does the Sankar’s law work?), the possibilities of ultrasound when monitoring the effectiveness of magnetic rods, the use of MRI simultaneously with MCGR, and the comparative cost of the method. Particular attention is paid to the problem of a uniform protocol of staged extension of rods. It seems that the initial enthusiasm has somewhat decreased. It is commonly agreed that new research is needed.

A high degree of variability exists in how "safety and efficacy" is defined and reported in growing rod surgery for early onset scoliosis: a systematic review.

Several publications have reported the safety and efficacy of traditional growing rods (TGR) and magnetically controlled growing rods (MCGR) using various parameters. Radiographic parameters are most commonly used to measure efficacy, while incidence and type of complications are used to assess safety. A systematic review of peer-reviewed articles was performed to identify whether a consensus exists in how safety and efficacy parameters are reported in EOS patients treated with TGR and MCGR. There is no consensus on the parameters used for reporting safety and efficacy in growing rod treatment for early onset scoliosis. Systematic literature review. Four databases were searched on November 10, 2016 to identify all qualified peer-reviewed articles using specific keyword searches. All peer-reviewed articles published in English language reporting any data related to safety and efficacy of the TGR and/or MCGR surgical technique were included. Articles that met the inclusion criteria were scored by modified Downs and Black scoring system (J Epidemiol Community Health 52(6):377-384, 1998) for non-randomized studies. All reported safety and efficacy data were extracted and analyzed. Search of the databases resulted in 111 unique citations including: PubMed (50), Embase (68 with 21 duplicates), Web of Science (29 with 15 duplicates), and CINAHL (15; all duplicates). Fifty-six of 111 citations were excluded during the review of the titles and abstracts. In addition, 16 citations were excluded at the time of full manuscript review. The remaining 39 articles included 23 TGR (2007-2016) and 16 MCGR papers (2012-2016). The overall Downs and Black score was 63.9 for TGR papers vs. 64.0 for MCGR papers (p = 0.97). Efficacy measures were not consistently reported among the publications. The only consistently reported efficacy parameter in majority (> 90%) of papers was curve size. Complication reporting was highly variable. Major curve size was the only consistent parameter to report efficacy in peer-reviewed TGR and MCGR publications. Since complications were not consistently reported, assessing safety of either treatment was infeasible. Establishing standardized safety and efficacy parameters in growing rod surgery for EOS would improve the quality of future studies and makes comparison of different treatment modalities possible. Indeed, other clinically relevant parameters such as health-related quality of life, pulmonary function, nutritional status, and psychiatric and developmental health should also be considered to improve the future safety and efficacy reporting.

Expert Consensus for Early Onset Scoliosis Surgery.

Despite a validated classification system, high-quality multicenter research databases (CSSG/GSSG), and a recent proliferation in publications, early-onset scoliosis (EOS) surgeons have no consensus on standards for surgical treatment. The 21st-century revolution in EOS care has only accelerated, with the arrival of a classification system, magnetically controlled growing rod, nusinersen, and improved nonoperative care (Mehta or Risser casting and compliance-monitored braces). This dizzying pace of change may have outstripped our ability to develop best-practice standards for EOS surgical indications. To learn where consensus is best (and worst) at this moment, we surveyed EOS world thought-leaders on a collection of representative cases. A 6-case survey was constructed and sent to 20 EOS world thought-leaders. The cases were selected to be representative of the major treatment categories: idiopathic, neuromuscular, syndromic, congenital, thoracic dysplasia, and spinal muscular atrophy (specifically to assess the impact of nusinersen and parasol deformity on surgical planning). Respondents were queried regarding treatment with specific attention to instrumentation and construct when surgery was selected. Responses regarding surgical timing and technique were analyzed for consensus (defined as >80%). χ analysis was performed to evaluate for differences in treatment preferences based on years of experience. The survey response was 100%. Clinical experience ranged from 8 to 40 years (average 23.9 y). There was no consensus on any case. The greatest variability was on the congenital case; the closest to consensus was on the spinal muscular atrophy case. Three or more approaches were selected for all 6 cases; >4 approaches were selected for 5 cases. There is a trend towards screw fixation for proximal anchors. The management of thoracic dysplasia and parasol deformity is far from consensus. The lack of consensus for surgical treatment of 6 representative EOS cases demands a renewed effort and commitment to develop best-practice guidelines based on multicenter outcome data. Level V-Expert Opinion.

The Safety and Efficacy of Intrathecal Morphine in Early Onset Scoliosis Surgery - A 25 Year Single Center Experience

The Safety and Efficacy of Intrathecal Morphine in Early Onset Scoliosis Surgery - A 25 Year Single Center Experience

Expert Consensus for Early Onset Scoliosis Surgery 2018

Expert Consensus for Early Onset Scoliosis Surgery 2018

Unplanned Reoperations in Magnetically Controlled Growing Rod Surgery for Early Onset Scoliosis With a Minimum of Two-Year Follow-Up.

A retrospective review of prospectively collected clinical and radiologic data of patients with magnetically controlled growing rods (MCGRs) from a multi-centered study with a minimum of 2-year follow-up. The aim of this study was to describe the incidence and causes of unplanned reoperations and to report the outcomes of patients treated with MCGR for early-onset scoliosis (EOS). Published clinical studies have demonstrated that MCGR is safe and effective for curvature control of EOS, and can avoid repeated surgeries for distractions. However, there have been no reports on the unplanned reoperations and complications of MCGR for EOS with a large series of patients. Between 2009 and 2012, 30 patients with EOS underwent MCGR implantation in six institutions. A retrospective review of prospectively collected clinical and radiologic data with a minimum of 2-year follow-up was conducted. Demographic data, radiologic measurements, unplanned reoperations, and other complications were noted. Risk factors for unplanned reoperations were analyzed. Patients underwent MCGR implantation at the mean age of 7.2 years. The mean follow-up period was 37 months. Fourteen patients (46.7%) underwent an unplanned reoperation within the follow-up period, with a mean time to reoperation of 23 months after initial surgery (range, 5-48 months). Causes of unplanned reoperation were failure of rod distractions, proximal foundation failure, rod breakage, and infection. More frequent distractions (between 1 week and 2 months) were associated with a higher rate of reoperation than distraction frequencies between 3 and 6 months (71% vs. 25%). This is the largest series with the longest follow-up to date that examines the need for additional unplanned surgery after the initial procedure. It highlights that MCGR surgery can be associated with unplanned reoperations, and more frequent distractions may be a risk factor. Long-term comparative studies with traditional growing rod are required to evaluate the effectiveness of this implant. 4.

The Recognition, Incidence, and Management of Spinal Cord Monitoring Alerts in Early-onset Scoliosis Surgery.

The objective of the research was to study the relevance of intraoperative neuromonitoring throughout all stages of surgical management in patients with progressive early-onset scoliosis (EOS).The routine monitoring of spinal cord potentials has gradually become standard of practice among spinal surgeons. However, there is not a consensus that the added expense of this technique necessitates monitoring in all stages of surgical management. A retrospective review of 180 surgical cases of 30 patients with EOS from July 2003 to July 2012 was performed. All monitoring alerts as judged by the neuromonitoring team were identified. Both somatosensory-evoked potentials and transcranial electric motor-evoked potentials were studied and no limiting thresholds for reporting electrophysiological changes were deemed appropriate. Of 150 monitored cases there were 18 (12%) monitoring alerts. This represented 40% of the patient cohort over the 9-year study period. Index versus routine lengthening rate of alerts showed no significant difference in incidence of monitoring alerts. Conversely, several patients whose primary implantation surgeries were uneventful had monitoring alerts later in their treatment course. Intraoperative neuromonitoring is warranted throughout all stages of surgical management of EOS. Level IV. This study is a retrospective review of surgical cases of 30 patients with EOS.

The Classification for Early-onset Scoliosis (C-EOS) Correlates With the Speed of Vertical Expandable Prosthetic Titanium Rib (VEPTR) Proximal Anchor Failure.

The Classification for Early-onset Scoliosis (C-EOS) was developed by a consortium of early-onset scoliosis (EOS) surgeons. This study aims to examine if the C-EOS classification correlates with the speed (failure/unit time) of proximal anchor failure in EOS surgery patients. A total of 106 EOS patients were retrospectively queried from an EOS database. All patients were treated with vertical expandable prosthetic titanium rib and experienced proximal anchor failure. Patients were classified by the C-EOS, which includes a term for etiology [C: Congenital (54.2%), M: Neuromuscular (32.3%), S: Syndromic (8.3%), I: Idiopathic (5.2%)], major curve angle [1: ≤20 degrees (0%), 2: 21 to 50 degrees (15.6%), 3: 51 to 90 degrees (66.7%), 4: >90 degrees (17.7%)], and kyphosis ["-": ≤20 (13.5%), "N": 21 to 50 (42.7%), "+": >50 (43.8%)]. Outcome was measured by time and number of lengthenings to failure. Analyzing C-EOS classes with >3 subjects, survival analysis demonstrates that the C-EOS discriminates low, medium, and high speed of failure. The low speed of failure group consisted of congenital/51-90/hypokyphosis (C3-) class. The medium-speed group consisted of congenital/51-90/normal and hyperkyphosis (C3N, C3+), and neuromuscular/51-90/hyperkyphosis (M3+) classes. The high-speed group consisted of neuromuscular/51-90/normal kyphosis (M3N), and neuromuscular/>90/normal and hyperkyphosis (M4N, M4+) classes. Significant differences were found in time (P<0.05) and number of expansions (P<0.05) before failure between congenital and neuromuscular classes.As isolated variables, neuromuscular etiology experienced a significantly faster time to failure compared with patients with idiopathic (P<0.001) and congenital (P=0.026) etiology. Patients with a major curve angle >90 degrees demonstrated significantly faster speed of failure compared with patients with major curve angle 21 to 50 degrees (P=0.011). The ability of the C-EOS to discriminate the speeds of failure of the various classification subgroups supports its validity and demonstrates its potential use in guiding decision making. Further experience with the C-EOS may allow more tailored treatment, and perhaps better outcomes of patients with EOS. Level III.

Osseointegration improves bone-implant interface of pedicle screws in the growing spine: a biomechanical and histological study using an in vivo immature porcine model.

Implant failure is a frequent complication in corrective surgery for early onset scoliosis, since considerable forces are acting on small and fragile vertebrae. Osseointegration showing biomechanical and histological improvement in bone-implant interface (BII) after dental implant placement has been well investigated. However, there are no studies regarding osseointegration in immature vertebral bone. The purpose was to evaluate the timecourse of biomechanical and histological changes at BII after pedicle screw placement using in vivo immature porcine model. Ten immature porcine were instrumented with titanium pedicle screws in the thoracic spine. After a 0-, 2-, 4-, and 6-month survival periods, the spines were harvested at the age of 12months. Histological evaluation of BII was conducted by bone volume/tissue volume (BV/TV) and bone surface/implant surface (BS/IS) measurements. Bone mineral density (BMD) measurement and biomechanical testing of BII were done. Contact surface and bone volume around the screw threads were significantly increased over the time. BV/TV and BS/IS were improved with statistically significant differences between 0- and ≥4-month (p≤0.001) periods. BMD in all subjects was determined to be the same (p≥0.350). Pullout strength was also increased over time with significant differences between 0- and ≥2-month (p≤0.011) periods. Improved stability at BII caused by osseointegration was confirmed by in vivo immature porcine model. A two-stage operation is proposed based on the osseointegration theory, in which an implant is installed in advance in the vertebrae at the first stage and deformity correction surgery is performed after sufficient stability is obtained by osseointegration at a later stage.

Paper #23 Spinopelvic Parameters Predict Development of Proximal Junctional Kyphosis in Early Onset Scoliosis

Retrospective cohort study of patients with EOS from 2 EOS registries, treated with growth-friendly surgery, looking into the relationship of preoperative spinopelvic alignment and development of postoperative proximal junctional kyphosis. A total of 135 children with min 2 yr f/up were included. Pre-op thoracic kyphosis and post-op spinopelvic parameters influence the development of PJK in children undergoing growth friendly surgery for early onset scoliosis.

Offset layered closure reduces deep wound infection in early-onset scoliosis surgery.

Deep wound infection is a common complication in early-onset scoliosis (EOS) surgery. Soft tissue technique has received less attention as a means to reduce infection. A retrospective review of 1170 EOS surgeries (single surgeon, institution) investigated the impact of offset layered closure (OLC) and soft tissue awareness. The introduction of OLC reduced deep infection from 3.0% in 99 surgeries to 0.37% in 1071. Logistic regression confirmed that OLC led to significantly lower odds of infection (P=0.007). This deep infection rate (0.37%) is more typical of elective surgery, providing a more optimistic view of infection in EOS surgery than generally reported.

Effect of growing rod on sagittal and spinopelvic parameters in early-onset scoliosis patients.

Growing rod is a commonly used surgery for early-onset scoliosis (EOS). However, the effect of growing-rod lengthening on the spinopelvic alignment is unclear. In this study, 21 EOS patients treated by growing rod were evaluated retrospectively and thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI) , sacral slope (SS), pelvic tilt (PT), and sagittal vertical axis (SVA) were measured. Preoperatively, the mean TK, LL, PI, PT, SS, and SVA were 27.4°, 35.2°, 43.8°, 7.5°, 33.8°, and 47.7 mm respectively. After the last lengthening, TK, LL, PI, PT, SS, and SVA were 28.3°, 28.06°, 41.4°, 7°, 5.2°, and 42.6 mm, respectively. The sagittal plane parameters in our EOS patients were not significantly altered during the lengthening period.