Anterior Scoliosis Correction (ASC) with anterior longitudinal ligament and annular disc complex (intervertebral) de-tethering releases is the authors’ multi-year advancement of their original mini-open vertebral body tethering technique to include a dual screw-line construct and multi-level intervertebral de-tethering releases. The study included patients diagnosed with early onset scoliosis, aged 5-10 years of age, Sanders stage 2 or less, Risser sign of 0, open triradiate cartilages, and a minimum of 2 years of follow-up. Within a database encompassing 840 patients treated by ASC, 15 patients (17 curves) met the inclusion criteria. The average duration of follow-up for this cohort was 48.3 months (range 25 to 86 months). The mean age at the time of surgery was 8 years (range 5.7 to 10.1 years). Preoperative scoliosis curves averaged 81° (range 58° to 100°). At the most recent follow-up, the instrumented curves improved to an average of 22° (range -15° to 68°) and mean correction of 75%. Preoperative 3-D kyphosis, calculated as an average of -6° (range -23° to +20°), was improved to an average of + 28° (range ‑1° to +59°) at latest follow-up. As may be anticipated with early onset scoliosis, 11 of the 15 patients underwent a secondary surgical procedure an average of 43 months following the index procedure. Of these 11, lengthening was necessary for overcorrection in 3 patients (20%), revision or subsequent stage ASC was done for additional correction adjustment in 6 patients (40%), and spinal fusion was performed in 2 patients (13%). In conclusion, a cohort of 15 patients aged 5-10 years with early onset scoliosis treated by ASC with intervertebral de-tethering releases (initial average curve of 81°) demonstrated a substantial mean correction of 75% in the instrumented curve. Although 2/15 patients (13%) subsequently underwent posterior spinal fusion, these early outcomes suggest a potential alternative to traditional posterior growing rod system approaches and posterior spinal fusion for these young patients.

Introduction: The evaluation of spinal range of motion is paramount in the context of spinal disorders, especially considering emerging surgical techniques focused on motion preservation and circumventing spinal fusion. Manual measurement techniques, which utilize a goniometer and tape measure, demand proficiency to accurately assess spinal motion. This becomes further complicated in patients with spinal deformities. Inertial sensors emerge as a potential clinical solution. By assessing electronic inertial sensor performance in capturing thoracolumbar spinal range of motion, this study evaluates the level of association observed between the range of motion measurements captured by manual and sensor methods. Methods: Participants included 19 healthy young adults (74% female, average age 20 years [range 15-26]) without spinal conditions. Each performed a series of manual spinal motion evaluations quantified using a standard goniometer and a tape measure. Participants repeated the motions with an electronic inertial sensor attached to their C7 spinous process. Each manual and electronic motion sequence was performed three times. Data were analyzed with a Pearson’s correlation to assess congruence between the datasets, and a paired t-test compared the mean values between the two groups to examine the two motion measurement methodologies. Results: Association between the different planes of motion for manual and electronic repeated clinical motions were moderate (r=0.44) to strong (r=0.70). Manual measurements showed similar levels of variation to that of the electronic measurements. Upon comparing the manual and electronic measurement sets through a paired t-test, the mean values exhibited no statistically significant differences. Conclusion: The electronic motion measurements were congruent with manual measurements based on the correlation values and t-tests presented. Thus, inertial sensors can approximate the measurements of manual methods in assessing spinal range of motion. This demonstrates the potential for clinical adaptation of these sensors into spine centers to objectively assess patient outcomes in spinal motion preserved surgeries.

To evaluate the motion-preserving properties of vertebral body tethering with varying cord/screw constructs and cord thicknesses in cadaveric thoracolumbar spines. In vitro flexibility tests were performed on six fresh-frozen human cadaveric spines (T1-L5) (2 M, 4F) with a median age of 63 (59-to-80). An ± 8 Nm load was applied to determine range of motion (ROM) in flexion–extension (FE), lateral bending (LB), and axial rotation (AR) in the thoracic and lumbar spine. Specimens were tested with screws (T5-L4) and without cords. Single (4.0 mm and 5.0 mm) and double (4.0 mm) cord constructs were sequentially tensioned to 100 N and tested: (1) Single 4.0 mm and (2) 5.0 mm cords (T5-T12); (3) Double 4.0 mm cords (T5-12); (4) Single 4.0 mm and (5) 5.0 mm cord (T12-L4); (6) Double 4.0 mm cords (T12-L4). In the thoracic spine (T5-T12), 4.0–5.0 mm single-cord constructs showed slight reductions in FE and 27–33

To develop a protocol for assessing spinal range of motion using an inertial sensor device. The baseline error of an inertial sensor was assessed using a bicycle wheel. Nineteen healthy subjects (12 females and 7 males, average age 18.2 ± 0.6 years) were then prospectively enrolled in a study to assess the reliability of an inertial sensor-based method for assessing spinal motion. Three raters each took three measurements of subjects’ flexion/extension, right and left bending, and right and left rotation. Afterwards, one trial from each set of measurements was excluded. Correlations and the ICC (3,1) were used to assess intra-rater reliability, and ICC (3,2) was used to assess inter-rater reliability of the protocol. The baseline error of the sensor was 1.45°. Correlation and ICC (3,1) values for the protocol all exceeded 0.888, indicating high intra-rater reliability. ICC (3,2) values for the protocol exceed 0.87, indicating high inter-rater reliability. Our study presents both a paradigm for assessing the baseline error of inertial sensors and a protocol for assessing motion of the spine using an inertial sensing device.

Previous work has suggested that surface topography can be used for repeated measurements of deformity during curve monitoring following an initial radiograph. Changes in deformity during natural curve progression may be subtle. An important preemptive question to answer is whether topography can follow a large change in spine deformity, as in scoliosis correction. We assess the ability of surface topography to track the evolution of spine deformity during anterior scoliosis correction relative to traditional radiographs. Anterior scoliosis correction was chosen for this analysis because it changes the shape of the trunk without leaving a surgical scar and muscle atrophy along the posterior spine. Following IRB approval, 18 patients aged 14.6 ± 2.0 years at surgery were enrolled in a retrospective review of coronal radiographs and topographic scans acquired before and after scoliosis correction. Radiographic and topographic measures for the coronal curve angle before and after surgery were compared. Surface topography estimates correlate with radiographic measures of the pre- (r = 0.7890, CI = [0.4989 0.9201], p < 0.00001), postsurgical (r = 0.7485, CI = [0.4329 0.9006], p = 0.0004), and the change in the coronal curve angle (r = 0.6744, CI = [0.3028 0.8680], p = 0.0021) due to surgery. We provide evidence open for further extension that topography can follow changes in the coronal curve angle comparably to radiographs. Level IV.

Treatment for adolescent idiopathic scoliosis (AIS) is dependent upon multiple factors, including curve type and magnitude, curve progression, skeletal maturity, and clinical trunk deformity. While fusion is effective at achieving curve correction, it is associated with disadvantages including prominent implants beneath the skin, back muscle scarring and atrophy, decreased spine range of motion, and decreased functional spinal mobility. Additional concerns include the potential for longer term development of premature adjacent level disc and facet joint degeneration above and below the fusion. Due to these issues with spinal fusion, surgeons have explored alternative surgical approaches to correct spinal deformity and halt curve progression using either growth modulation or remodeling of the spine while preserving motion. This paper provides an overview of a non-fusion scoliosis correction technique called Anterior Scoliosis Correction (ASC).

Case report (review of patient records, imaging, and pulmonary function tests) and literature review. To describe the case of a skeletally immature patient with Marfan syndrome who underwent anterior scoliosis correction (ASC) and muscle-sparing posterior far lateral interbody fusion (FLIF) in a two-stage procedure to correct progressive severe double major scoliosis and spondylolisthesis. Patients with Marfan syndrome suffer from rapidly progressive scoliosis and spondylolisthesis. Operative treatment has typically been limited to PSF, but newer techniques may be less invasive and provide more spine motion. A 12-year-old girl with Marfan syndrome, spondylolisthesis, and severe progressive scoliosis underwent a two-stage procedure to achieve correction. Muscle-sparing posterior FLIF of the spondylolisthesis from L4–S1 was initially performed, followed 1 week later by ASC from right T4–T11 and left T11–L3 using an anterior screw/cord construct. Follow-up from the index procedures for the spondylolisthesis and scoliosis is 35 months. No significant complications occurred in perioperative and postoperative follow-up periods. At the 13-month follow-up, the double major scoliosis showed continued curve correction via growth modulation and overcorrection of the lumbar to − 13°. A revision lengthening procedure of the anterior cord from T11–L3 was performed. An asymptomatic elevated hemidiaphragm was discovered at 6 weeks postoperation, which was believed to be secondary to retraction neuropraxia and subsequently improved. At 21 months postlengthening and 35 months postindex procedure, she is skeletally mature and the curves have maintained correction in both the coronal and sagittal planes without any further complications. Anterior scoliosis correction of both a thoracic and lumbar curve combined with an L4–S1 PSF was effective for this patient and may be promising for patients with Marfan syndrome, progressive scoliosis, and spondylolisthesis. Overcorrection can be planned for and easily corrected by inserting a new cord of a different length.

Ninety-eight percent of skeletally immature patients with spinal cord injury (SCI) suffer from progressive neuromuscular scoliosis (NMS). Operative treatment has typically been limited to posterior spinal fusion (PSF), but a newer technique as described may be less invasive and preserve more function. A PSF of the entire spine to the pelvis is standard of care. However, maintenance of spinal flexibility, motion, and potential growth is desirable. We present a case for proof-of-concept of utilizing a surgical motion-preserving technique to treat progressive NMS in an 11year-old girl with T10 level (AIS B) paraplegia with a progressive 60° NMS of the lumbar spine. She had anterior scoliosis correction (ASC) from T11-L5 without fusion. Over 24 months, the curve growth-modulated to a residual of 12° with continued modulation to 7° at 3-year follow-up (skeletal maturity).

The standard of care for skeletally immature patients with idiopathic scoliosis is bracing for moderate curves. The standard of care for both skeletally immature and mature patients who have more severe or progressive curves is spinal fusion. We present a summary of four currently used non-fusion surgical techniques as alternatives to bracing and spinal fusion. Vertebral body stapling (VBS) is suggested for patients between the ages of 8 and 13 yr for girls and younger than 15 yr for boys with at least one year of growth remaining (Risser 0-1, Sanders digital stage ≤4). Thoracic curves should measure 25-35 degrees and lumbar curves 25-45 degrees. For best results, the curves should be flexible, bending to < 20 degrees. Correction with a cord/screw construct includes vertebral body tethering (VBT) and anterior scoliosis correction (ASC), which are most commonly being performed for skeletally immature patients (Risser 0-2, Sanders digital stage ≤4) with thoracic and lumbar curves between 30-70 degrees that bend to < 30 degrees. The authors of this article have expanded the indications for treating adolescents with idiopathic scoliosis who are more mature (Risser > 2) with ASC. One commercial product has received CE mark approval in Europe for ASC treatment in both skeletally immature and mature patients. A second product utilizing posterior dynamic concave distraction, also with CE mark approval in Europe, is indicated for patients who are 10-17 yr old with primary single main thoracic or thoracolumbar curves between 30-60 degrees that correct to ≤35 degrees on bending films.

Purpose. We report a comparison study of vertebral body stapling (VBS) versus a matched bracing cohort for immature patients with moderate (25 to 44°) idiopathic scoliosis (IS). Methods. 42 of 49 consecutive patients (86%) with IS were treated with VBS and followed for a minimum of 2 years. They were compared to 121 braced patients meeting identical inclusion criteria. 52 patients (66 curves) were matched according to age at start of treatment (10.6 years versus 11.1 years, resp. [P = 0.07]) and gender. Results. For thoracic curves 25–34°, VBS had a success rate (defined as curve progression <10°) of 81% versus 61% for bracing (P = 0.16). In thoracic curves 35–44°, VBS and bracing both had a poor success rate. For lumbar curves, success rates were similar in both groups for curves measuring 25–34°. Conclusion. In this comparison of two cohorts of patients with high-risk (Risser 0-1) moderate IS (25–44°), in smaller thoracic curves (25–34°) VBS provided better results as a clinical trend as compared to bracing. VBS was found not to be effective for thoracic curves ≥35°. For lumbar curves measuring 25–34°, results appear to be similar for both VBS and bracing, at 80% success.

OBJECT:Several studies have characterized the relationship among postoperative thoracic, lumbar, and pelvic alignment in the sagittal plane. However, little is known of the relationship between postoperative thoracic kyphosis and sagittal cervical alignment in patients with adolescent idiopathic scoliosis (AIS) treated with all pedicle screw constructs. The authors examined this relationship and associated factors. METHODS:A prospective database of pediatric patients with AIS undergoing spinal fusion between 2003 and 2005 was reviewed for those who received predominantly pedicle screw constructs for Lenke Type 1 or Type 2 curves. Parameters analyzed on pre- and postoperative radiographs were the fusion levels; cervical, thoracic, and lumbar sagittal balance; and C-2 and C-7 plumb lines. RESULTS:Preoperatively, 6 (Group A) of the 22 patients included in the study had frank cervical kyphosis (mean angle 13.0°) with mean associated thoracic kyphosis of 27.2° (range 16°-37°). Postoperatively, cervical kyphosis (13.0°) remained in the patients in Group A along with mean thoracic kyphosis of 17.7° (range 4°-26°, p < 0.05). Preoperatively, the remaining 16 of 22 patients had neutral to lordotic cervical alignment (mean -13.8°) with thoracic kyphosis (mean 45°, range 30°-76°). Postoperatively, 8 (Group B) of these 16 patients demonstrated cervical sagittal decompensation (> 5° kyphosis), with 6 showing frank cervical kyphosis (10.5°, p < 0.05). In Group B, the mean postoperative thoracic kyphosis was 25.6° (range 7°-49°, p < 0.05). The other 8 patients (Group C) had mean postoperative thoracic kyphosis of 44.1° (range 32°-65°), and there was no cervical decompensation (p < 0.05). CONCLUSIONS:The sagittal profile of the thoracic spine is related to that of the cervical spine. The surgical treatment of Lenke Type 1 and 2 curves by using all pedicle screw constructs has a significant hypokyphotic effect on thoracic sagittal plane alignment (19 [86%] of 22 patients). If postoperative thoracic kyphosis is excessively decreased (mean 25.6°, p < 0.05), the cervical spine may decompensate into significant kyphosis.

STUDY DESIGN:Retrospective case review of skeletally immature patients treated with growing rods. Patients received an average of 9.6 years follow-up care.OBJECTIVE:(1) to identify the rate of autofusion in the growing spine with the use of growing rods; (2) to quantify how much correction can be attained with definitive instrumented fusion after long-term treatment with growing rods; and (3) to describe the extent of Smith-Petersen osteotomies required to gain correction of an autofused spine following growing rod treatment.SUMMARY OF BACKGROUND DATA:The safety and use of growing rods for curve correction and maintenance in the growing spine population has been established in published reports. While autofusion has been reported, the prevalence and sequelae are not known.METHODS:Nine skeletally immature children with scoliosis were identified who had been treated using growing rods. A retrospective review of the medical records and radiographs was conducted and the following data collected: complications, pre- and postoperative Cobb angles at time of initial surgery (growing rod placement), pre- and postoperative Cobb angles at time of final surgery (growing rod removal and definitive fusion), total spine length as measured from T1-S1, % correction since initiation of treatment and at definitive fusion, total number of surgeries, and number of patients found to have autofusion at the time of device removal.RESULTS:The rate of autofusion in children treated with growing rods was 89%. The average percent of the Cobb angle correction obtained at definitive fusion was 44%. On average, 7 osteotomies per patient were required at the time of definitive fusion due to autofusion.CONCLUSION:Although growing rods have efficacy in the control of deformity within the growing spine, they also have adverse effects on the spine. Immature spines treated with a growing rod have high rates of unintended autofusion which can possibly lead to difficult and only moderate correction at the time of definitive fusion.

The use of thoracic pedicle screws for the treatment of adolescent idiopathic scoliosis (AIS) has gained widespread popularity. However, the placement of pedicle screws in the deformed spine poses unique challenges, and surgeons experience a learning curve. The in vivo accuracy as determined by computed tomography (CT) of placement of thoracic pedicle screws in the deformed spine as a function of surgeon experience is unknown. We undertook a retrospective review to determine the effect of surgeon experience on the accuracy of thoracic pedicle screw placement in AIS. In 2005, we started to obtain routine postoperative CT scans on patients undergoing a spinal fusion. From a database of these patients, we selected AIS patients, who underwent a posterior spinal fusion. Fifteen consecutive patients for each of the following three groups stratified by attending surgeon experience were selected (N = 45): A) less than 20 cases of all pedicle screw constructs for AIS (surgeons <2 years of practice), B) 20–50 cases (surgeons 2–5 years of practice), and C) greater than 50 cases (surgeons greater than 5 years of practice). Intraoperative evaluation of all screws included probing of the pedicle screw tract, neurophysiologic monitoring, and fluoroscopic confirmation. A total of 856 thoracic pedicle screws were studied. Postoperative CT scans were evaluated by two spine surgeons and a consensus read established as follows: (1) In: intraosseous placement or ≤2-mm breach, (2) Out: >2-mm breach, either medial or lateral. Of the 856 screws, 104 demonstrated a >2-mm breach, for an overall rate of 12.1% (medial = 55, lateral = 49, P = 0.67). When the breach rates were stratified by surgeon experience, there was a trend toward decreased rate of breach for the most experienced surgeons, although this did not attain statistical significance (Group A: 12.7%, Group B: 12.9%, Group C: 10.8%, P = 0.58). However, the most experienced group (C) had a markedly decreased rate of medial breaches (3.5 vs. 7.4% and 8.4% for groups A and B, respectively, P < 0.01). The breach rate for the concave periapical screws was not statistically different from the overall breach rate (13.0% vs. 12.1%, P = 0.93). In conclusion, the overall accuracy of placement of pedicle screws in the deformed spine was 87.9%, with no neurologic, vascular, or visceral complications. Meticulous technique allows spine surgeons with a range of surgical experience to accurately and safely place thoracic pedicle screws in the deformed spine. The most experienced surgeons demonstrated the lowest rate of medial breaches.

BACKGROUND CONTEXT: Traditionally, thoracoplasty with spinal fusion has been used to treat thoracic coronal and rotational deformity associated with AIS. More recently, the use of pedicle screw fixation and the subsequent development of techniques for axial derotation have allowed for correction of the chest wall deformity. Previous studies have shown siginificant rotational correction with segmental pedicle screws and direct vertebral body derotation. However, to date, no studies have compared the residual rib prominence and percent correction in patients with thoracoplasty versus all pedicle screw and direct vertebral body derotation.

BACKGROUND CONTEXT: There have been several attempts to characterize the relationship between thoracic kyphosis, lumbar lordosis, and pelvic alignment in sagittal balance but none to correlate the effect of postoperative thoracic kyphosis on the cervical spine.

Study Design. Single-surgeon retrospective case series of 303 consecutive operative patients with idiopathic scoliosis (IS).Objective. The purpose of this study is to evaluate the perioperative outcomes in patients undergoing surgery for IS as a function of the experience level of the surgical assistant.Summary of Background Data. The experience level of the surgical assistant, who is often a resident or fellow, has never before been evaluated as an independent factor in predicting perioperative outcomes and morbidity in scoliosis surgery. We hypothesize that there is no difference in perioperative outcomes with varying experience level of the surgical assistant.Methods. We evaluated the clinical, radiographic, and operative records from 303 consecutive operative patients from consecutive patients with IS. Group I was comprised of residents or spine fellows as assistants (teaching service, n = 175), and Group II consisted of junior or senior attendings as assistants (private practice service, n = 128). Multivariable linear regression was used to evaluate the relationship between experience level of the assistant and curve correction, operative time, estimated blood loss (EBL), complications, transfusions, and length of stay.Results. In the posterior spinal fusion group (PSF, n = 164), there were no statistically significant differences in operative times between Groups I and II. Group I operative time was significantly increased, however, in patients undergoing anterior spinal surgery (ASF, P = 0.01), video-assisted thoracoscopic surgery (P = 0.0004), and combined anterior/posterior surgeries (ASF/PSF, P = 0.0063). There were no differences in EBL in ASF, video-assisted thoracoscopic surgery, or PSF surgeries, however, Group I had significantly higher EBL in the ASF/PSF group (P = 0.0016). No group differences were detected with respect to curve correction, transfusion rates, length of stay, or early complication rates.Conclusion. The experience level of surgical assistant had little bearing on perioperative morbidity or radiographic outcomes in scoliosis surgery. Marginally increased operative times and EBL, without an increase in transfusions or complications, is an acceptably safe tradeoff for educating orthopedic residents and fellows.

BACKGROUND CONTEXT: Surgery for idiopathic scoliosis (IS) may be associated with longer surgical times, increased blood loss, and a potentially higher rate of perioperative complications compared with other orthopaedic procedures. The experience level of the surgical assistant, who is often a resident or fellow, has never before been evaluated as a factor in predicting perioperative outcomes and morbidity in scoliosis surgery. We hypothesize that there is no difference in perioperative outcomes with varying experience level of the surgical assistant.

Study Design. Consecutive case prospective radiographic and medical record review.Objective. To define the learning curve associated with thoracoscopic spinal instrumentation by evaluating operative data and early outcomes of 1 surgeon's ( B. L.) cases.Summary of Background Data. Thoracoscopic spinal instrumentation for the treatment of thoracic adolescent idiopathic scoliosis has emerged as an alternative to open anterior and posterior techniques. The technique is technically demanding and has been perceived as having a prohibitive learning curve.Methods. The operative reports, charts, and surgeon's database were used to evaluate operating time, estimated blood loss, levels fused, complication rate, blood transfusions, and curve correction, among other variables. For purposes of analysis, the entire cohort was divided into 2 groups of 28 and 29 patients, respectively, and then 4 groups of 14 patients ( the last group with 15) were used for comparison.Results. The records of 57 patients were evaluated. No significant difference in estimated blood loss or number of levels fused was noted for either comparison ( P = 0.46 and P = 0.66, respectively). There was no significant difference in blood transfusion requirements, with 7% in group 1 and 18% in group 2 ( P = 0.35). Operating time was significantly less after 28 patients were operated on 6.2 +/- 1.3 hours versus 5.3 +/- 1.2 hours ( P = 0.011). Percent curve correction was significantly better after 28 cases were performed, 54.4 +/- 17.9 in the former groups versus 65.7 +/- 10.4 in the latter half of cases ( P = 0.005). Complications were evenly distributed throughout the series. No significant differences were observed between the 2 groups in terms of rate of complication ( P = 0.50). No major complications, such as neurologic deficit or significant hemorrhage, were observed.Conclusions. The learning curve associated with thoracoscopic spinal instrumentation appears to be acceptable. Significant differences were noted in operating time and percent curve correction after 28 cases. The complication rates remained stable throughout the surgeon's experience.