Proximal foundation anchor variations and their correlation with unplanned return to the operating room (UPROR) in children with EOS treated with magnetically controlled growing rods (MCGR).

INTRODUCTION: The evolution of MCGR technique has led to modifications in the configuration of the proximal construct to decrease the incidence of implant-related complications (IRC) and revision surgeries. However, there is no data characterizing the performance of the most used configurations reducing the risk of complications. METHODS: 487 patients were identified from an international multicenter EOS database. INCLUSION CRITERIA: EOS patients, primary dual MCGR, complete radiographs, and minimum of 2-year follow-up. 76 patients had incomplete X-rays, 5 had apical fusions, and 18 had inconclusive complications, leaving 388 patients for review. A digital spine template was created to document UIV; number of levels; number, type, and location of anchors; as well as implant configuration. First available postoperative and latest follow-up radiographs were reviewed by two senior surgeons and two spine fellows. UPROR due to IRC was defined as any change in proximal anchors between the postoperative and final follow-up radiographs. RESULTS: The most common proximal construct configuration: UIV at T2 (50.0%) with 17.5% UPROR, followed by T3 (34.0%) with 12.1% UPROR; number of levels was three (57.1%) with 16.8% UPROR and two (26.0%) with 17.0% UPROR; number of proximal anchors was six (49.9%) with 14.1% UPROR and four (27.0%) with 18.3% UPROR. The most common anchors were all screws (42.0%) with 9.9% UPROR, and all hooks (26.4%) with 31.4% UPROR (P < 0.001). The construct with the lowest rate of UPROR was a UIV at T2, with six anchors (all screws) across three levels (42 cases), with 0% UPROR. Other construct combinations that yielded 0% UPROR rates were UIV of T3, six anchors (all screws) across three levels (25 cases), and a UIV of T3 with six anchors (screws and hooks) across three3 levels (9 cases). CONCLUSION: Proximal anchor configuration impacts the incidence of UPROR due to IRC in MCGR. UIV at T2 and T3 compared to T4, and the use of all screws or combination of screws and hooks compared to all hooks were associated with a lower UPROR rate. The most common construct configuration was T2 UIV, three levels, six anchors, and all screws. The use of a combination of six anchors (screws or screws and hooks) across three levels with a UIV at T2 or T3 was associated with a lower UPROR rate. Additional research is needed to further evaluate the variables contributing to configuration selection and their association with IRC.

Incidence of postoperative neurological deficit with the use of an intraoperative neuromonitoring protocol for lateral lumbar interbody fusion.

OBJECTIVE: Intraoperative neuromonitoring (IONM) has become commonplace in assessing neurological integrity during lateral approaches to lumbar interbody fusion surgeries. Neuromonitoring is designed to aid surgeons in identifying the potential for intraoperative nerve injury and reducing associated postoperative complications. However, standardized protocols for neuromonitoring have not been provided, and outcomes are not well described. The purpose of this study was to provide a standardized protocol for IONM, and to describe clinical outcomes in a cohort of individuals who underwent lateral lumbar interbody fusion (LLIF) surgery. METHODS: A retrospective review of 169 consecutive patients who underwent LLIF surgery at a single institution from October 2014 to October 2016 was performed. Patient characteristics, intraoperative details, clinical outcomes, and postoperative deficits (PODs) were compared between patients who did and did not trigger IONM alerts, and between patients who did and did not demonstrate a POD. A protocol for IONM decision-making was generated based on these observations. RESULTS: Most patients (91.7%) underwent surgery for a degenerative spine condition. Twenty-three patients (13.6%) triggered neuromonitoring alerts, and 16 patients (9.5%) demonstrated a POD. Leg pain, back pain, and disability improved significantly (p < 0.045), and 2 patients had both motor and sensory deficits at the 12-week postoperative time point. Patients with a POD demonstrated greater operating room time (p = 0.034) and a greater number of interbody fusion levels (p = 0.015) but were less likely to have triggered a neuromonitoring alert (p = 0.04). There was no association between retractor time and POD (p = 0.98). When an IONM protocol was followed, individuals who experienced a POD were less likely to trigger an alert than those who did not experience a POD (p = 0.04). CONCLUSIONS: This study provides a protocol algorithm for IONM alert responses in patients undergoing LLIF surgery. PODs are most associated with multilevel fusion, and patients with alerts had a low rate of persistent deficit. Future research is needed to validate these findings using a more rigorous comparative study design.

Establishing a Standardized Clinical Consensus for Reporting Complications Following Lateral Lumbar Interbody Fusion.

Background and Objectives: Mitigating post-operative complications is a key metric of success following interbody fusion. LLIF is associated with a unique complication profile when compared to other approaches, and while numerous studies have attempted to report the incidence of post-operative complications, there is currently no consensus regarding their definitions or reporting structure. The aim of this study was to standardize the classification of complications specific to lateral lumbar interbody fusion (LLIF). Materials and Methods: A search algorithm was employed to identify all the articles that described complications following LLIF. A modified Delphi technique was then used to perform three rounds of consensus among twenty-six anonymized experts across seven countries. Published complications were classified as major, minor, or non-complications using a 60% agreement threshold for consensus. Results: A total of 23 articles were extracted, describing 52 individual complications associated with LLIF. In Round 1, forty-one of the fifty-two events were identified as a complication, while seven were considered to be approach-related occurrences. In Round 2, 36 of the 41 events with complication consensus were classified as major or minor. In Round 3, forty-nine of the fifty-two events were ultimately classified into major or minor complications with consensus, while three events remained without agreement. Vascular injuries, long-term neurologic deficits, and return to the operating room for various etiologies were identified as important consensus complications following LLIF. Non-union did not reach significance and was not classified as a complication. Conclusions: These data provide the first, systematic classification scheme of complications following LLIF. These findings may improve the consistency in the future reporting and analysis of surgical outcomes following LLIF.

Is spinal height gain associated with rod orientation and the use of cross-links in magnetically controlled growing rods in early-onset scoliosis?

Optimal orientation for magnetically controlled growing rods (MCGRs) is unclear. The objective of this study was to investigate associations of rod orientation with implant-related complications (IRCs) and spinal height gains. Using an international early-onset scoliosis (EOS) database, we retrospectively reviewed 57 patients treated with dual MCGRs from May 2013 to July 2015 with minimum 2-year follow-up. Outcomes of interest were IRCs and left/right rod length gains and thoracic (T1-T12) and spinal (T1-S1) heights. We compared patients with two rods lengthened in the cephalad ( standard; n  = 18) versus opposite ( offset; n  = 39) directions. Groups did not differ in age, sex, BMI, duration of follow-up, EOS cause, ambulatory status, primary curve magnitude, baseline thoracic height, or number of distractions/year. We compared patients whose constructs used ≥1 cross-link (CL group; n  = 22) versus no CLs (NCL group; n  = 35), analyzing thoracic height gains per distraction ( α  = 0.05). Offset and standard groups did not differ in left or right rod length gains overall or per year or in thoracic or spinal height gain. Per distraction, the CL and NCL groups did not differ significantly in left or right rod length or thoracic or spinal height gain. Complications did not differ significantly between rod orientation groups or between CL groups. MCGR orientation and presence of cross-links were not associated with differences in rod length gain, thoracic height, spinal height, or IRCs at 2-year follow-up. Surgeons should feel comfortable using either MCGR orientation. Level of evidence: 3, retrospective.

Outcomes of Growth-friendly Instrumentation in Osteogenesis Imperfecta: A Preliminary Report.

BACKGROUND: There is limited literature on the outcomes in patients with osteogenesis imperfecta (OI) undergoing growth-friendly instrumentation (GFI). The purpose of this study was to report the outcomes of GFI in patients with early-onset scoliosis (EOS) and OI. We hypothesized that similar trunk elongation could be obtained in OI patients, but with higher complication rates. METHODS: A multicenter database was studied for patients with EOS and OI etiology who had GFI from 2005 to 2020, with a minimum 2-year follow-up. Demographic, radiographic, clinical, and patient-reported outcomes data were collected and compared with an idiopathic EOS cohort matched 2:1 for age, follow-up duration, and curve magnitude. RESULTS: Fifteen OI patients underwent GFI at a mean age of 7.3±3.0 years, with an average follow-up of 7.3±3.9 years. OI patients had a mean preoperative coronal curve of 78.1±14.5 and achieved 35% correction after index surgery. There were no differences in major coronal curves and coronal percent correction between the OI and idiopathic groups at all time points. T1-S1 length (cm) was lower for the OI group at baseline (23.3±4.6 vs. 27.7±7.0; P =0.028) but both groups had similar growth (mm) per month (1.0±0.6 vs. 1.2±1.1; P =0.491). OI patients had a significantly increased risk of proximal anchor failure, which occurred in 8 OI patients (53%) versus 6 idiopathic patients (20%) ( P =0.039). OI patients who underwent preoperative halo-traction (N=4) had greater T1-S1 length gain (11.8±3.2 vs. 7.3±2.8; P =0.022) and greater percent major coronal curve correction (45±11 vs. 23±17; P =0.042) at final follow-up versus patients with no halo-traction (N=11). Staged foundation fusion was performed in 2 cases. CONCLUSION: Compared with matched idiopathic EOS patients, OI patients undergoing GFI achieved similar radiographic outcomes but sustained greater rates of anchor failures, likely due to weakened bone. Preoperative halo-traction was a useful adjunct and may improve final correction. Staged foundation fusion is an idea to consider for difficult cases. LEVEL OF EVIDENCE: Therapeutic-III.

Definition of Tweener: Consensus Among Experts in Treating Early-onset Scoliosis.

BACKGROUND: The term "Tweener" is colloquially used to refer to early-onset scoliosis (EOS) patients whose age and development make them candidates for multiple surgical options. The purpose of this study was to establish expert consensus on a definition to formally characterize the Tweener population. METHODS: A 3-round survey of surgeons in an international EOS study group was conducted. Surgeons were provided with various patient characteristics and asked if each was part of their definition for Tweener patients. Responses were analyzed for consensus (≥70%), near-consensus (60% to 69%), and no consensus (<60%). RESULTS: Consensus was reached (89% of respondents) for including chronological age in the Tweener definition; 8 to 10 years for females and 9 to 11 years for males. Surgeons agreed for inclusion of Sanders score, particularly Sanders 2 (86.0%). Patients who have reached Sanders 4, postmenarche, or have closed triradiate cartilage should not be considered Tweeners. Bone age range of 8 years and 10 months to 10 years and 10 months for females (12 y for males) could be part of the Tweener definition. CONCLUSIONS: This study suggests that the Tweener definition could be the following: patients with open triradiate cartilage who are not postmenarche and have not reached Sanders 4, and if they have one of the following: Sanders 2 or chronological age 8 to 10 years for females (9 to 11 y for males) or bone age 8 years and 10 months to 10 years and 10 months for females (12 y for males). This definition will allow for more focused and comparative research on this population. LEVEL OF EVIDENCE: Level V-expert opinion.

Surgical treatment of young adults with idiopathic scoliosis.

OBJECTIVE: In this study, the authors report on their experience with the surgical treatment of young adults with idiopathic scoliosis (YAdISs) who did not have surgical treatment in adolescence but did require intervention after skeletal maturity. METHODS: The medical records of YAdISs between 18 and 40 years of age who had been surgically treated at two institutions between 2009 and 2018 were retrospectively evaluated. Pre- and postoperative clinical and radiographic information was gathered and compared at 2 years after treatment. RESULTS: Twenty-eight patients (9 male, 19 female) with a median age of 25 years (range 18-40 years) met the study inclusion criteria. Five patients (18%) had postoperative complications, including 2 deep venous thromboses, 1 ileus, and 2 reoperations, one for implant failure and the other for pseudarthrosis. The mean maximum coronal curve angle improved from 43° ± 12° to 17° ± 8° (p < 0.001), but there were no significant differences in sagittal vertical axis, lumbar lordosis, pelvic tilt, or thoracic kyphosis (p > 0.05). There was no relationship between the amount of correction obtained and patient age (p = 0.46). Significant improvements in the Oswestry Disability Index (31 vs 24, p = 0.02), visual analog scale score for both back pain (6.0 vs 4.0, p = 0.01) and leg pain (2.6 vs 1.1, p = 0.02), and self-image score (Δ1.1, p < 0.001) were seen. CONCLUSIONS: YAdISs can present with pain, deformity progression, and/or appearance dissatisfaction because of their scoliosis despite successful nonoperative management during adolescence. Once the scoliosis becomes symptomatic, surgical correction can result in significant clinical and radiographic improvements at the 2-year follow-up with a relatively low complication rate compared to that for other types of adult spinal deformity.

Re-evaluating consensus and uncertainty among treatment options for early onset scoliosis: a 10-year update.

PURPOSE: Consensus and uncertainty in early onset scoliosis (EOS) treatment were evaluated in 2010. It is currently unknown how treatment preferences have evolved over the past decade. The purpose of this study was to re-evaluate consensus and uncertainty among treatment options for EOS patients to understand how they compare to 10 years ago. METHODS: 11 pediatric spinal surgeons (similar participants as in 2010) were invited to complete a survey of 315 idiopathic and neuromuscular EOS cases (same cases as in 2010). Treatment options included the following: conservative management, distraction-based methods, growth guidance/modulation, and arthrodesis. Consensus was defined as ≥ 70% agreement, and uncertainty was < 70%. Associations between case characteristics and consensus for treatments were assessed via chi-squared and multiple regression analyses. Case characteristics associated with uncertainty were described. RESULTS: Eleven surgeons [31.7 ± 7.8 years of experience] in the original 2010 cohort completed the survey. Consensus for conservative management was found in idiopathic patients aged ≤ 3, whereas in 2010, some of these cases were selected for surgery. There is currently consensus for casting idiopathic patients aged 1 or 2 with moderate curves, whereas in 2010, there was uncertainty between casting and bracing. Among neuromuscular cases with consensus for surgery, arthrodesis was chosen for patients aged 9 with larger curves. CONCLUSION: Presently, preferences for conservative management have increased in comparison to 2010, and casting appears to be preferred over bracing in select infantile cases. Future research efforts with higher levels-of-evidence should be devoted to elucidate the areas of uncertainty to improve care in the EOS population. LEVEL OF EVIDENCE: Level V.

Can a bioactive interbody device reduce the cost burden of achieving lateral lumbar fusion?

OBJECTIVE: Intervertebral devices are increasingly utilized for fusion in the lumbar spine, along with a variety of bone graft materials. These various grafting materials often have substantial cost burdens for the surgical procedure, although they are necessary to overcome the limitations in healing capacity for many traditional interbody devices. The use of bioactive interbody fusion devices, which have demonstrable stimulatory capacity for the surrounding osteoblasts and osteoprogenitor cells and allow for osseointegration, may reduce this heavy reliance on osteobiologics for achieving interbody fusion. The objective of this study was to evaluate the rate of successful interbody fusion with a bioactive lateral lumbar interbody titanium implant with limited volume and low-cost graft material. METHODS: The authors conducted a retrospective study (May 2017 to October 2018) of consecutively performed lateral lumbar interbody fusions with a bioactive 3D-printed porous titanium interbody device. Each interbody device was filled with 2-3 cm3/cage of a commercially available ceramic bone extender (ß-tricalcium phosphate-hydroxyapatite) and combined with posterior pedicle screw fixation. No other biological agents or grafts were utilized. Demographic, clinical, and radiographic variables were captured. Fusion success was the primary endpoint of the study, with graft subsidence, fixation failure, and patient-reported outcomes (Oswestry Disability Index [ODI] and visual analog scale [VAS]-back and -leg pain scores) collected as secondary endpoints. The authors utilized a CT-based fusion classification system that accounted for both intervertebral through-growth (bone bridging) and ingrowth (integration of bone at the endplate-implant interface). RESULTS: In total, 136 lumbar levels were treated in 90 patients. The mean age was 69 years, and 63% of the included patients were female. Half (50.0%) had undergone previous spinal surgery, and a third (33.7%) had undergone prior lumbar fusion. A third (33.7%) were treated at multiple levels (mean levels per patient 1.51). One year after surgery, the mean improvements in patient-reported outcomes (vs preoperative scores) were -17.8 for ODI (p < 0.0001), -3.1 for VAS-back pain (p < 0.0001), and -2.9 for VAS-leg pain (p < 0.0001). Bone bridging and/or appositional integrity was achieved in 99.3% of patients, including 97.8% who had complete bone bridging. No fixation loosening or implant failure was observed at any segment. Low-grade graft subsidence (Marchi grade ≤ I) occurred in 3 levels (2.2%), and intraoperative endplate violation occurred twice (1.5%). High-grade subsidence was not found. No implant failure or revision surgery for pseudarthrosis/subsidence was necessary. CONCLUSIONS: The use of bioactive titanium interbody devices with a large surface footprint appears to result in a very high rate of effective fusion, despite the use of a small volume of low-cost biological material. This potential change in the osteobiologics required to achieve high fusion rates may have a substantially beneficial impact on the economic burden inherent to spinal fusion.

Trends in the Utilization of Implants in Index Procedures for Early Onset Scoliosis From the Pediatric Spine Study Group.

INTRODUCTION: Because of the relative rarity of Early Onset Scoliosis (EOS) cases, patient registries were developed to combine clinical information from multiple institutions to maximize patient care and outcomes. This study examines the history and trends regarding the use of growth-friendly devices for index surgical procedures in EOS patients within the Pediatric Spine Study Group database. METHODS: All index growth-friendly implants were queried from registry inception until October 2020. EOS etiology, device/implant type, and geographic area/institution for each procedure were recorded. RESULTS: From 1994 to 2020, 2786 patients underwent index surgery at a mean age of 6.2±2.9 years. There were 908 traditional growing rods (TGR) (32.3%), 922 vertical expandable prosthetic titanium rib devices (VEPTR) (33.1%), 5 hybrid VEPTR/TGR (0.18%), and 951 magnetically controlled growing rods (MCGR) (34.2%) index implants. Fifty-six different institutions reported an index implant, and 5 accounted for 823 (30%) of the cases during the study period. Institutions in the Northeast accounted for more index implants than other regions of the United States. There was a 40% increase in index implant insertions annually when comparing 1994 (3 implants/1 center) to 2018 (234 implants/56 centers), ( P <0.001). Beginning in 2009, there was a 90.9% decrease in the number of TGR/VEPTR procedures (2009: 156 implants/32 centers; 2019: 22 implants/49 centers P =0.001), and a 479% increase in MCGR (2009: 1 implant/1 center; 2018: 197 implants/34 centers ( P =0.005). The overall number of growth-friendly index procedures performed in 2019 (150/49 centers) decreased 34.5% when compared to 2018 (234/48 centers). CONCLUSION: The number of growth-friendly implants reported in the Pediatric Spine Study Group registry as the initial surgical management of EOS increased markedly over the past 20 years. MCGR is currently the predominant type of device utilized for index surgical procedures by group members, surpassing the use of VEPTR and TGR in 2014. There was a significant decrease in index growth-friendly procedures in 2019 compared to 2018. LEVEL OF EVIDENCE: Level IV.

Contraindications to magnetically controlled growing rods: consensus among experts in treating early onset scoliosis.

PURPOSE: The purpose of this study was to describe contraindications to the magnetically controlled growing rod (MCGR) in patients with early onset scoliosis (EOS) by establishing consensus amongst expert surgeons who treat these patients frequently. METHODS: Nine pediatric spine surgeons from an international EOS study group participated in semi-structured interviews via email to identify factors that influence decision making in the use of MCGR. A 39-question survey was then developed to specify these factors as contraindications for MCGR-these included patient age and size, etiology, medical comorbidities, coronal and sagittal curve profiles, and skin and soft tissue characteristics. Pediatric spine surgeons from the EOS international study group were invited to complete the survey. A second 29-item survey was created to determine details and clarify results from the first survey. Responses were analyzed for consensus (> 70%), near consensus (60-69%), and no consensus/variability (< 60%) for MCGR contraindication. RESULTS: 56 surgeons of 173 invited (32%) completed the first survey, and 64 (37%) completed the second survey. Responders had a mean of over 15 years in practice (range 1-45) with over 6 years of experience with using MCGR (range 2-12). 71.4% of respondents agreed that patient size characteristics should be considered as contraindications, including BMI (81.3%) and spinal height (84.4%), although a specific BMI range or a specific minimum spinal height were not agreed upon. Among surgeons who agreed that skin and soft tissue problems were contraindications (78.6%), insufficient soft tissue (98%) and skin (89%) to cover MCGR were specified. Among surgeons who reported curve stiffness as a contraindication (85.9%), there was agreement that this curve stiffness should be defined by clinical evaluation (78.2%) and by traction films (72.3%). Among surgeons who reported sagittal curve characteristics as contraindications, hyperkyphosis (95.3%) and sagittal curve apex above T3 (70%) were specified. Surgeons who indicated the need for repetitive MRI as a contraindication (79.7%) agreed that image quality (72.9%) and not patient safety (13.6%) was the concern. In the entire cohort, consensus was not achieved on the following factors: patient age (57.4%), medical comorbidities (46.4%), etiology (53.6%), and coronal curve characteristics (58.9%). CONCLUSION: Surgeon consensus suggests that MCGR should be avoided in patients who have insufficient spinal height to accommodate the MCGR, have potential skin and soft tissue inadequacy, have too stiff a spinal curve, have too much kyphosis, and require repetitive MRI, particularly of the spine. Future data-driven studies using this framework are warranted to generate more specific criteria (e.g. specific degrees of kyphosis) to facilitate clinical decision making for EOS patients. LEVEL OF EVIDENCE: Level V-expert opinion.

Ilizarov kyphectomy technique in the management of the gibbus deformity with an open wound in meningomyelocele patients: a case report with five years of follow-up.

PURPOSE: To propose an alternative method of surgical technique to address gibbus deformity in meningomyelocele with open wound simultaneously. METHODS: We report a rare case of an 8-year-old girl with a refractory skin breakdown on her gibbus deformity, which underwent an Ilizarov kyphectomy technique to address her skin breakdown, and spinal deformity at the same time, while planning a definitive fusion in the future. RESULTS: The patient was followed up for about 5 years. Her spine and overlying skin seem stable and no definite fusion has been offered to the patient so far. CONCLUSION: Ilizarov kyphectomy technique is an alternative procedure that can provide a safe and effactive method to address severe kyphosis deformity with skin breakdown. However, a comparison should be drawn to other procedures, while including more patients with longer follow-up.

Treatment of Early-onset Scoliosis: Similar Outcomes Despite Different Etiologic Subtypes in Traditional Growing Rod Graduates.

BACKGROUND: It is unclear whether traditional growing rod (TGR) treatment outcomes vary by early-onset scoliosis (EOS) subtype. The goal of this study was to compare radiographic outcomes and complications of TGR treatment by EOS subtype. METHODS: We queried an international database of EOS patients from 20 centers to identify "graduates" who had (1) undergone primary TGR treatment from 1993 to 2014; (2) completed TGR treatment; and (3) had an uneventful clinical examination within 6 months after completion of TGR treatment with no anticipated further intervention. We included 202 patients in 4 etiologic subgroups: neuromuscular (n=65), syndromic (n=57), idiopathic (n=52), and congenital (n=28). Mean age at surgery was 7.1 years (range, 1.6 to 14.9 y); mean duration of follow-up was 8 years (range, 2 to 18.6 y). The groups did not differ by mean age, body mass index, sex, number of lengthenings, or duration of follow-up. The following preoperative differences were significant: (1) greater mean major curve in the neuromuscular versus idiopathic subgroup; (2) shorter spinal height (T1-S1) in the congenital versus idiopathic subgroup; and (3) smaller proportion of ambulatory patients in the neuromuscular subgroup versus all other subgroups. RESULTS: We found no significant differences among subgroups in mean major curve correction or changes in thoracic height (T1-T12), spinal height, or global kyphosis at any point. Rates of deep surgical site infection, implant-related complications, and neurological complications were not different among subgroups. The medical complication rate was significantly lower in the idiopathic group compared with the other groups. CONCLUSIONS: Major curve correction and spinal and thoracic height increases did not differ significantly at any point by EOS subtype. Rates of deep surgical site infection, implant-related complications, and neurological complications did not differ by subtype. Except for the lower rate of medical complications in the idiopathic group, our findings suggest that, after TGR treatment, patients can expect similar outcomes regardless of their EOS subtype. LEVEL OF EVIDENCE: Level III, therapeutic.

Prevalence of junctional kyphosis in early-onset scoliosis: can it be corrected at final fusion?

PURPOSE: To investigate the risk and predictive factors of junctional issues after conversion from Traditional growing rod (TGR) to definitive spinal fusion in Early-onset scoliosis (EOS). METHODS: Retrospective review of a multicenter EOS database. TGR patients who received final fusion with at least two-year follow-up were included. Proximal (PJA) and Distal junctional angles (DJA) on pre-final fusion, post-final fusion (within one year of surgery), and at latest follow-up were measured on lateral upright spinal radiographs. Differences in values among designated time points and predictive factors of junctional issues were evaluated statistically. RESULTS: Forty-six of 251 patients (28 females, 18 males and mean age at final fusion: 12 ± 2 [9-17] years) met the inclusion criteria. Mean follow-up between first postoperative measurement and latest follow-up was 49 ± 22 (24-112) months. No statistical differences in PJA and DJA values were available at pre-fusion, first post-fusion, or latest follow-up (p = 0.827, p = 0.076). Fifty percent of patients had extension of TGR instrumentation at fusion, either proximal or distal. No factor including sex and etiology, lumbar lordosis, thoracic kyphosis, major curve magnitude, PJA, and DJA at pre-fusion was found to be a predictive issue for extension of index TGR instrumentation, except the history of at least one implant-related complication during the period from index surgery to the definitive fusion. CONCLUSION: PJA and DJA remained stable when transitioning from TGR to final posterior spinal fusion. But 50% of patients had extension of construction at fusion, either proximal or distal.

The role of traditional growing rods in the era of magnetically controlled growing rods for the treatment of early-onset scoliosis.

PURPOSE: To describe the clinical and radiographic profile of early-onset scoliosis (EOS) patients treated with traditional growing rods (TGR) during the magnetically-controlled growing rod (MCGR) era. METHODS: A US multicenter EOS database was reviewed to identify (1) patients who underwent TGR after MCGR surgery was introduced at their institution, (2) patients who underwent MCGR during the same time period. Of 19 centers, 8 met criteria with all EOS etiologies represented. Clinical notes were reviewed to determine the indication for TGR. Patient demographics and pre-operative radiographs were compared between groups. RESULTS: A total of 25 TGR and 127 MCGR patients were identified. The TGR patients were grouped by indication into the sagittal plane profile (n = 11), trunk height (n = 6), co-morbidities/need for MRI (n = 4), and other (ex: behavioral issues, remaining growth). Four patients had a combination of sagittal profile and short stature with sagittal profile listed as primary factor. The TGR short trunk group had a mean T1-S1 length of 192 mm vs 273 mm for the MCGR group (p = 0.0002). The TGR sagittal profile group, had a mean maximal kyphosis of 61° vs 55° for the MCGR group (p = 0.09). CONCLUSION: TGR continues to have a role in the MCGR era. In this study, the most commonly reported indications for TGR were sagittal plane profile and trunk height. These results suggest that TGR is indicated in patients of short stature with stiff hyperkyphotic curves. As further experience is gained with MCGR, the indications for TGR will likely be refined.

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.

Effect of race, age, and gender on lumbar muscle volume and fat infiltration in the degenerative spine.

BACKGROUND: The quantity and quality of spinal muscles in patients with degenerative spinal diseases and various backgrounds such as age, gender, or race is unclear. We quantitatively evaluated the cross-sectional area (CSA) and fatty degeneration of the muscles around the spine, using magnetic resonance imaging (MRI) in patients with degenerative spinal disease, and studied the effects of age, gender, and race in multicenter retrospective study. METHODS: The subjects were Caucasian and Asian patients with degenerative lumbar disease who underwent L4-5 single level spinal fusion surgery at centers in the United States and Japan. Using preoperative axial T2 MRI at the L4-5 disc level, the cross-sectional areas of the psoas and paraspinal muscles were measured. Fat infiltration was measured using the threshold method, and percent fat area (%FA) was calculated for each muscle. The muscle/disc area ratio (MDAR) was used to control for size differences per patient. T-test, Pearson's correlation coefficient, partial correlation, and multiple linear regression were used for statistical analysis. RESULTS: In total, 140 patients (53 men; 87 women; mean age, 69.2 years) were analyzed. Age was similar in Caucasians (n = 64) and Asians (n = 76). MDARs were larger in Caucasians for paraspinal and psoas muscles (p < 0.005). Percent FA of psoas was similar in Caucasians and Asians, but greater in the paraspinal muscles of Asians (p < 0.05). After controlling for race and gender, age was correlated negatively with MDAR (p < 0.001) and positively with %FA (p < 0.001). In the multiple linear regression analysis, age, gender, and race were independently affected by MDAR and %FA. CONCLUSIONS: Lumbar muscle mass and quality were affected by age, gender, and race, independently, in patients with degenerative lumbar disease.