New Technologies in Pediatric Spine Surgery

Paraspinous Muscle Flaps in Complex Pediatric Spine Surgeries: A 12-Year Single Institution Experience

PURPOSE

The benefits of paraspinous flaps in adult complex spine surgery patients are established in the literature; however, their use in pediatric patients has not been well described. This study compares clinical outcomes with and without paraspinous muscle flap closure in pediatric patients who have undergone spine surgery.

METHODS

We conducted a retrospective review of all pediatric spine surgeries at the University of California, San Francisco from 2011 to 2022. Patients were divided into 2 cohorts based on whether the plastic surgery service closed or did not close the wound with paraspinous muscle flaps. We matched patients by age, American Society of Anesthesiology classification, prior spinal surgical history, and diagnosis. Surgical outcomes were compared between the 2 cohorts.

RESULTS

We identified 226 pediatric patients who underwent at least one spinal surgery, 14 of whom received paraspinous flap closure by plastic surgery. They were matched in a 1:4 ratio with controls (n = 56) that did not have plastic surgery closure. The most common indication for plastic surgery involvement was perceived complexity of disease by the spine surgeon with concern for inadequate healthy tissue coverage (78.6%), followed by infection (21.4%). Postoperative complications were similar between the two groups. The plastic surgery cohort had a higher rate of patients who were underweight (57.1% vs 14.3%, P < 0.01) and had positive preoperative wound cultures (28.6% vs 8.9%, P = 0.05), as well as a higher rate of postoperative antibiotic usage (78.6 vs 17.9%, P < 0.01). There was no difference in recorded postoperative outcomes.

CONCLUSIONS

Spine surgeons requested paraspinous flap closure for patients with more complex disease, preoperative infections, history of chemotherapy, or if they were underweight. Patients with paraspinous flap coverage did not have increased postoperative complications despite their elevated risk profile. Our findings suggest that paraspinous muscle flaps should be considered in high-risk pediatric patients who undergo spine surgery.

Can anterior vertebral body tethering provide superior range of motion outcomes compared to posterior spinal fusion in adolescent idiopathic scoliosis? A systematic review

PURPOSE

Anterior vertebral body tethering (AVBT) was introduced as a fusionless alternative to treating adolescent idiopathic scoliosis (AIS) while preserving range of motion (ROM). This is the first systematic review to compare the ROM outcomes between AVBT and PSF in treating AIS.

METHODS

We conducted a comprehensive search on PubMed, EMBASE, MEDLINE, and Cochrane Library. Inclusion criteria were patients with AIS treated with AVBT or PSF or both, and clearly defined ROM outcomes; exclusion criteria were scoliosis other than AIS, biomechanical or cadaveric studies, non-English publications, case reports, conference summaries, unpublished literature, commentaries, and reviews. Primary outcome was ROM. Secondary outcomes included Cobb angle correction, quality of life (QOL), complications, and muscle strength and endurance.

RESULTS

Twelve studies were included in this review. We found moderate evidence to support that AVBT results in superior ROM outcomes than PSF while achieving comparable Cobb angle correction with low evidence. The comparison of QOL outcomes between AVBT and PSF remained inconclusive. In addition to the complications noted conventionally in PSF, AVBT could result in over-correction and distal adding-on. We also found very low evidence to support that AIS patients treated with AVBT have superior muscle strength and endurance when compared to those treated with PSF.

CONCLUSIONS

AVBT provides better preservation of ROM and muscle strength postoperatively when compared with PSF, while achieving comparable curve correction. Future studies should explore the spinal growth trajectory to determine the window of opportunity for AVBT in AIS.

Implant-Related Complications Do Not Interfere with Corrections with the Shilla Technique in Early Onset Scoliosis: Preliminary Results

Growth-preservation techniques are utilized in early onset scoliosis (EOS) cases requiring surgical intervention. The Shilla technique corrects the deformity by reducing additional surgeries with its growth-guidance effect. As with other techniques, various problems can be encountered following the administration of the Shilla technique. The aim of this study was to examine the effect of complications encountered with the Shilla treatment on correction and growth. Sixteen patients with a follow-up period of at least one year after receiving Shilla growth guidance for EOS were included in this retrospective study. No complications occurred, and no unplanned surgery was required in 50% of the cases. Of the remaining eight patients with postoperative implant-related complications (50%), six (37.5%) required unplanned surgery; this consequently caused implant failure in the proximal region in five cases (31.25%) and deep tissue infection around the implant in one case (6.25%). Deformity correction, spine length, and quality-of-life scores significantly improved in EOS through Shilla growth guidance. In terms of spinal growth and deformity correction, there were no significant differences between patients with implant-related problems and individuals without occurrences. Although implant-related problems were detected in our dataset and corresponding unexpected surgeries were necessary, these complications had no significant unfavorable influence on correction and spine growth.

Diseases and comorbidities associated with early-onset scoliosis: a retrospective multicenter analysis

PURPOSE

To determine the frequencies of various diseases associated with all types of early-onset scoliosis, both idiopathic and nonidiopathic.

METHODS

Retrospective collection of patients within a 21-year interval. Children under 10 years old presenting with scoliosis were included. Medical records were used to collect: identifier, date of birth, sex, diagnosis, follow-up, curve pattern, comorbidities, initial and final cobb angle. Different patient variables were tabulated with associated comorbidities for comparison.

RESULTS

The cohort contained 469 patients, with 227(48.4%) males and 242(51.6%) females. Total comorbidities equaled 1051, where 190 were unique. Only 124(26.4%) patients had an isolated diagnosis of early-onset scoliosis, 79(16.8%) had a single comorbidity, and 266(56.7%) had multiple comorbidities. "Global developmental delay" was most commonly observed, 198(42.2%) times. The central nervous system was involved more often than other organ systems, seen in 394(54.4%) instances. Males had more comorbidities than females. Idiopathic patients had the least number of comorbidities, while neuromuscular patients had the most. Idiopathic types had more musculoskeletal conditions, while congenital types had more cardiovascular diseases. Curve sides did not affect distributions. Cases which progressed had more comorbidities, especially in the respiratory, digestive, and cardiovascular systems. Diseases that could affect either extremity or side, were more likely to be bilateral.

CONCLUSIONS

Early-onset scoliosis patients may present with complex comorbidities in multiple organ systems. The most commonly observed disease entities were: global developmental delay, developmental dysplasia of the hip, and epilepsy. Clinicians should be aware of the common associations, in order to screen for and begin appropriate investigations, referrals, and treatments in affected cases.

LEVEL OF EVIDENCE

Level III.

Reliability of radiographic assessment of growth modulation from anterior vertebral body tethering surgery in pediatric scoliosis

PURPOSE

To assess the reliability of vertebral height and angular measurements for anterior vertebral body tethering (AVBT).

METHODS

Eight observers measured PA radiographs of 15 idiopathic scoliosis patients treated with AVBT, pre-operative and 4-year follow-up. Vertebral wedging, disc wedging, convex vertebral body heights, and concave vertebral body heights of the 3 apical vertebrae were measured. For each observer, there were a total of 90 measurements for vertebral body height and 75 measurements for all wedging types At least 14 days elapsed between first and second round measurements.

RESULTS

From the pre-operative to the 4-year follow-up time-point, the total wedging angle over the 3 peri-apical levels fell from 30 ± 7° to 16 ± 6° (p < 0.001) and the difference between the convex and concave vertebral heights decreased from 9 ± 4 to 6 ± 3 mm (p < 0.001). Interobserver agreement for pre-operative vertebral body heights was good [ICC = 0.80; 95% CI (0.74-0.85)]. At 4-year follow-up there was a moderate agreement [ICC = 0.67 (0.59-0.74)]. There was a poor interobserver agreement for pre-operative wedging angle measurements [ICC = 0.41 (0.32-0.52)] and 4-year follow-up [ICC = 0.45 (0.36-0.56)]. The Limits of Agreement with the Mean (LOAM) for pre-op heights was ± 2.4 mm, similar to the follow-up ± 2.6 mm. When raters are averaged in random groups of two the agreement limits decrease to ± 1.8 mm pre-op and ± 1.6 mm at follow-up. Similarly for wedging angles, LOAM values among the 8 observers of ± 4.6° pre-op and ± 4.2° dropped to ± 2.7° for both pre-op and follow-up when random groups of two raters were averaged together. Intraobserver agreement ranged from good to excellent per individual (ICC = 0.84-0.94) for pre-operative vertebral body heights, but this decreased at 4-year follow-up (ICC = 0.52-0.88). Intraobserver agreement was low overall for wedging (pre-operative ICC = 0.41-0.71; 4-year follow-up ICC = 0.41-0.76).

CONCLUSION

Based on 8 individual observers, interobserver agreement ranged from good (pre-operative vertebral body heights) to moderate (4-year follow-up vertebral body heights) to poor (all wedging angles). To improve the reliability of the measurement of wedging angles, we recommend averaging the measurements of at least two observers.

The incidence and prevalence of early-onset scoliosis: a regional multicenter epidemiological study

BACKGROUND CONTEXT

Despite the many advances in understanding and treating early-onset scoliosis, the incidence and prevalence of this disease in the population remains unknown. Such knowledge is important for guiding clinical practice, directing research and raising awareness.

PURPOSE

To identify the incidence and prevalence of early-onset scoliosis, including all categories, within the population.

STUDY DESIGN

A regional multicenter retrospective cohort study PATIENT SAMPLE: All patients diagnosed with early-onset scoliosis in the region, who were followed-up between January 2000 and December 2020.

OUTCOME MEASURES

Frequency distributions for early-onset scoliosis subtypes, demographics, curve patterns and progression statuses.

METHODS

Relevant population data, for children under 10 years old, was extracted from the official government census for the years 2000 to 2020. Identification of cases was carried out by pediatricians at mandatory government funded regular child wellness check-up visits. Outpatient records were reviewed for all included patients, with extraction of the following: Medical identifier, date of birth, date of initial visit, sex, primary diagnosis, length of follow-up, curve pattern, initial cobb angle, and final cobb angle. Incidence and prevalence values were calculated using population figures and case numbers. Kaplan-Meier survival analysis and Log-rank testing was performed on curve progression data.

RESULTS

The regional population of children, under the age of 10 years, included a total of 2,295,929 children, 1,170,149 (51.0%) males and 1,125,780 (49.0%) females, between the years 2000 and 2020. Early-onset scoliosis cases followed within the same timeframe, totaled 469 patients, 227 (48.4%) males and 242 (51.6%) females. The annual incidence of early-onset scoliosis was found to be 0.019% (95% CI: 0.015%-0.023%), and the prevalence was 0.077% (95% CI: 0.059%-0.096%). The most common age at first presentation was 6 years old. More females (51.6%) than males (48.4%) were observed, and more left-sided curves (54.2%) than right-sided curves (45.8%) were encountered, with the majority being single thoracic curves (38.2%). Scoliosis curves did not progress in 44.3% of cases, while they progressed in 38% of them. Follow-up was inadequate to determine progression status in 17.7% of cases. Neuromuscular etiologies were the most common, at 40.1%, of which 83.5% had cerebral palsy.

CONCLUSIONS

Based on the regional population included in this study, the annual incidence of early-onset scoliosis in children under 10 years old was calculated to be 0.019%, while the prevalence of early-onset scoliosis in children under 10 years old was found to be 0.077%.

Late spinal infections following posterior spinal fusion in pediatric deformities: treatment using single-stage titanium implant exchange

PURPOSE

Late infection following posterior spinal fusion (PSF) for deformity is a leading cause of revision. The purpose of this study is to evaluate clinical and radiographic outcomes following a single-stage debridement and exchange of spinal implants with titanium in adolescent patients with late-onset infections following PSF METHODS: A retrospective review of prospectively collected data of adolescent patients with spinal deformity, who were surgically treated with PSF was collected. Patients were included for the study if they developed late arising infection (> 1 year after index posterior fusion for the deformity) from 2006-2019. Treatment consisted of irrigation, debridement, implant exchange with titanium screws and rods, and antibiotics. Parameters evaluated include radiographic Cobb angles, operative data, and clinical data, all at minimum 2-year follow-up.

RESULTS

31 patients (29 with AIS and 2 with Scheuermann's kyphosis) developed late spinal infections. Mean age was 11.4 ± 2.3 years, 84% female, mean time from index surgery was 52.5 months. 25 had all stainless steel implants and 6 had cobalt chrome during the index procedure. Positive cultures were obtained in 5 patients (2 Staphylococcus Aureus, 1 Staphylococcus epidermidis, 1 Peptostreptococcus, 1 Pseudomonas aeruginosa) with cultures followed till 7 days post-operatively. At 2-years following the exchange, there was no change in coronal and sagittal alignment. Three (9%) patients developed subsequent infection necessitating implant removal.

CONCLUSION

A single-stage procedure consisting of implant removal, irrigation, and debridement, and replacement with all titanium implants is an effective treatment strategy in patients developing late wound infection following PSF with regards to maintenance of curve correction and minimizing recurrent infections.

Intraoperative neurophysiologic monitoring in idiopathic scoliosis surgery: a retrospective observational study of new neurologic deficits

PURPOSE

Patients with adolescent idiopathic scoliosis undergoing corrective surgery are at risk for iatrogenic spinal cord injury and subsequent new neurologic deficits (NNDs). Intraoperative neurophysiologic monitoring (IONM) has been used to identify spinal cord injury; however, available data showing that IONM leads to improved clinical outcomes are inconclusive. This exploratory study aimed to examine the incidence of NNDs after idiopathic scoliosis surgery in two pediatric institutions in Canada with a focus on IONM use.

METHODS

Charts of pediatric patients (10-18 yr) with adolescent idiopathic scoliosis who underwent scoliosis correction surgery were retrospectively identified from the operating room database. Data regarding incidence and severity (mild [isolated sensory deficit] vs severe [any motor deficit]) of NNDs as well as demographic and clinical characteristics were extracted.

RESULTS

Of 547 patients reviewed, 359 (66%) underwent IONM and 186 (34%) underwent wake-up test. Neuromonitoring data were missing in two patients. Total incidence of NNDs was 4.9% (95% confidence interval [CI], 3.1 to 6.8). Compared with the wake-up test, patients undergoing IONM were less likely to develop NNDs (unadjusted odds ratio, 0.39; 95% CI, 0.18 to 0.86; P = 0.02). Nevertheless, subgroup analysis did not reveal a statistical difference in severity of those deficits (mild vs severe) with IONM vs wake-up test. Combined anterior and posterior approach was also significantly associated with increased risk of such deficits.

CONCLUSION

This exploratory study revealed that IONM was associated with a reduced overall incidence of NNDs in idiopathic scoliosis correction; however, its impact on the severity of those deficits is questionable. As we were unable to adjust for confounding variables, further research is needed to determine the impact of IONM on NNDs.

Treatment of early-onset scoliosis: techniques, indications, and complications. Chin Med J (Engl). 2020;133:351-357. [PMID: 31904727 PMCID: PMC7004623 DOI: 10.1097/cm9.0000000000000614]

The treatments for early-onset scoliosis (EOS) remain great challenges for spine surgeons. This study aimed to comprehensively review the treatments for EOS, especially the advancements made in the last decade. Current studies on EOS were retrieved through a search on PubMed, UpToDate, the Web of Science Core Collection and Scopus were reviewed. The most pertinent information related to the current treatments for EOS was collected. The foci of treatments for EOS have included creating a well-developed thoracic cavity, improving lung volume, and improving pulmonary function. Conservative treatments include bracing, casting, halo-gravity traction, and physiotherapy. Serial casting is the most effective conservative treatment for EOS. Surgical treatments mainly include growth-friendly techniques, which are generally classified into three types according to the amount of correction force applied: distraction-based, compression-based, and growth-guided. The distraction-based systems include traditional or conventional growing rods, magnetically controlled growing rods, and vertical expandable prosthesis titanium ribs. The compression-based systems include vertebral body stapling and tethering. The growth-guided systems include the Shilla system and modern Luque trolley. In addition, some newer techniques have emerged in recent years, such as posterior dynamic deformity correction (ApiFix). For EOS patients presenting with sharp deformities in a long, congenital spinal deformity, a hybrid technique, one-stage posterior osteotomy with short segmental fusion and dual growing rods, may be a good choice. Hemivertebra resection is the gold standard for congenital scoliosis caused by single hemivertebra. Although the patient's growth potential is preserved in growth-friendly surgeries, a high complication rate should be expected, as well as a prolonged treatment duration and additional costs. Knowledge about EOS and its treatment options is rapidly expanding. Conservative treatments have specific limitations. For curves requiring a surgical intervention, surgical techniques may vary depending on the patients' characteristics, the surgeon's experience, and the actual state of the country.

Brace treatment in adolescent idiopathic scoliosis: risk factors for failure-a literature review

Brace treatment is the most common nonoperative treatment for the prevention of curve progression in adolescent idiopathic scoliosis. The success reported in level 1 and 2 clinical trials is approximately 75%. The aim of this review was to identify the main risk factors that significantly reduce success rate of brace treatment. A literature search using the MEDLINE and Embase databases was conducted. Studies were included if they identified specific risk factor(s) for curve progression. Studies that looked at nighttime braces, superiority of one type of brace over another, the effect of physical therapy on brace performance, cadaver or nonhuman studies were excluded. A total of 1,022 articles were identified of which 25 met all of the inclusion criteria. Seven risk factors were identified: Poor brace compliance (eight studies), lack of skeletal maturity (six studies), Cobb angle over a certain threshold (six studies), poor in-brace correction (three studies), vertebral rotation (four studies), osteopenia (two studies), and thoracic curve type (two studies). Three risk factors were highly repeated in the literature which identified specific subgroups of patients who have a much higher risk to fail brace treatment and to progress to fusion. This data demonstrates that 60% to 70% of the patients referred to bracing are Risser 0 and 30% to 70% of this group will not wear the brace enough to ensure treatment efficacy. Furthermore, Risser 0 patients who reach the accelerated growth phase with a curve ≥40° are at 70% to 100% risk of curve progression to the fusion surgical threshold despite proper brace wear. Skeletally immature patients with relatively large magnitude scoliosis who are noncompliant are at a higher risk of failing brace treatment.