Intraoperative navigation increases the projected lifetime cancer risk in patients undergoing surgery for adolescent idiopathic scoliosis

BACKGROUND CONTEXT

Adolescent idiopathic scoliosis (AIS) is a common condition, often requiring surgical correction. Computed tomography (CT) based navigation technologies, which rely on ionizing radiation, are increasingly being utilized for surgical treatment. Although this population is highly vulnerable to radiation, given their age and female predominance, there is little available information elucidating modeled iatrogenic cancer risk.

PURPOSE

To model lifetime cancer risk associated with the use of intraoperative CT-based navigation for surgical treatment of AIS.

STUDY DESIGN/SETTING

This retrospective cross-sectional study took place in a quaternary care academic pediatric hospital in the United States.

PATIENT SAMPLE

Adolescents aged 10-18 who underwent posterior spinal fusion for a diagnosis of AIS between July 2014 and December 2019.

OUTCOMES MEASURES

Effective radiation dose and projected lifetime cancer risk associated with intraoperative doses of ionizing radiation.

METHODS

Clinical and radiographic parameters were abstracted, including total radiation dose during surgery from flat plate radiographs, fluoroscopy, and intraoperative CT scans. Multivariable regression analysis was used to assess differences in radiation exposure between patients treated with conventional radiography versus intraoperative navigation. Radiation exposure was translated into lifetime cancer risk using well-established algorithms.

RESULTS

In total, 245 patients were included, 119 of whom were treated with navigation. The cohort was 82.9% female and 14.4 years of age. The median radiation exposure (in millisieverts, mSv) for fluoroscopy, radiography, and navigation was 0.05, 4.14, and 8.19 mSv, respectively. When accounting for clinical and radiographic differences, patients treated with intraoperative navigation received 8.18 mSv more radiation (95%CI: 7.22-9.15, p<.001). This increase in radiation projects to 0.90 iatrogenic malignancies per 1,000 patients (95%CI 0.79-1.01).

CONCLUSIONS

Ours is the first work to define cancer risk in the setting of radiation exposure for navigated AIS surgery. We project that intraoperative navigation will generate approximately one iatrogenic malignancy for every 1,000 patients treated. Given that spine surgery for AIS is common and occurs in the context of a multitude of other radiation sources, these data highlight the need for radiation budgeting protocols and continued development of lower radiation dose technologies.

LEVEL OF EVIDENCE

Therapeutic, III.

Two-Surgeon Multidisciplinary Approach to Pediatric Cervical Spinal Fusion: A Single-Institution Series and Review of the Literature

BACKGROUND

A collaborative 2-surgeon approach is becoming increasingly popular in surgery but is not widely used for pediatric cervical spine fusions. The goal of this study is to present a large single-institution experience with pediatric cervical spinal fusion using a multidisciplinary 2-surgeon team, including a neurosurgeon and an orthopedic surgeon. This team-based approach has not been previously reported in the pediatric cervical spine literature.

METHODS

A single-institution review of pediatric cervical spine instrumentation and fusion performed by a surgical team composed of neurosurgery and orthopedics during 2002-2020 was performed. Demographics, presenting symptoms and indications, surgical characteristics, and outcomes were recorded. Particular focus was given to describe the primary surgical responsibility of the orthopedic surgeon and the neurosurgeon.

RESULTS

A total of 112 patients (54% male) with an average age of 12.1 (range 2-26) years met the inclusion criteria. The most common indications for surgery were os odontoideum with instability (n=21) and trauma (n=18). Syndromes were present in 44 (39%) cases. Fifty-five (49%) patients presented with preoperative neurological deficits (26 motor, 12 sensory, and 17 combined deficits). At the time of the last clinical follow-up, 44 (80%) of these patients had stabilization or resolution of their neurological deficit. There was 1 new postoperative neural deficit (1%). The average time between surgery and successful radiologic arthrodesis was 13.2±10.6 mo. A total of 15 (13%) patients experienced complications within 90 days of surgery (2 intraoperative, 6 during admission, and 7 after discharge).

CONCLUSIONS

A multidisciplinary 2-surgeon approach to pediatric cervical spine instrumentation and fusion provides a safe treatment option for complex pediatric cervical cases. It is hoped that this study could provide a model for other pediatric spine groups interested in implementing a multi-specialty 2-surgeon team to perform complex pediatric cervical spine fusions.

LEVEL OF EVIDENCE

Level IV-case series.

Operative Treatment of Cervical Spine Injuries Sustained in Youth Sports

BACKGROUND

Little data exists on surgical outcomes of sports-related cervical spine injuries (CSI) sustained in children and adolescent athletes. This study reviewed demographics, injury characteristics, management, and operative outcomes of severe CSI encountered in youth sports.

METHODS

Children below 18 years with operative sports-related CSI at a Level 1 pediatric trauma center were reviewed (2004 to 2019). All patients underwent morden cervical spine instrumentation and fusion. Clinical, radiographic, and surgical characteristics were analyzed.

RESULTS

A total of 3231 patients (mean, 11.3±4.6 y) with neck pain were evaluated for CSI. Sports/recreational activities were the most common etiology in 1358 cases (42.0%). Twenty-nine patients (2.1%) with sports-related CSI (mean age, 14.5 y; range, 6.4 to 17.8 y) required surgical intervention. Twenty-five were males (86%). Operative CSI occurred in football (n=8), wrestling (n=7), gymnastics (n=5), diving (n=4), trampoline (n=2), hockey (n=1), snowboarding (n=1), and biking (n=1). Mechanisms were 27 hyperflexion/axial loading (93%) and 2 hyperextension injuries (7%). Most were cervical fractures (79%) and subaxial injuries (79%). Seven patients (24%) sustained spinal cord injury (SCI) and 3 patients (10%) cord contusion or myelomalacia without neurological deficits. The risk of SCI increased with age (P=0.03). Postoperatively, 2 SCI patients (29%) improved 1 American Spinal Injury Association Impairment Scale Grade and 1 (14%) improved 2 American Spinal Injury Association Impairment Scale Grades. Increased complications developed in SCI than non-SCI cases (mean, 2.0 vs. 0.1 complications; P=0.02). Bony fusion occurred in 26/28 patients (93%) after a median of 7.2 months (interquartile range, 6 to 15 mo). Ten patients (34%) returned to their baseline sport and 9 (31%) to lower-level activities.

CONCLUSIONS

The incidence of sports-related CSI requiring surgery is low with differences in age/sex, sport, and injury patterns. Older males with hyperflexion/axial loading injuries in contact sports were at greatest risk of SCI, complications, and permanent disability. Prevention campaigns, education on proper tackling techniques, and neck strength training are required in sports at high risk of hyperflexion/axial loading injury.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Growth-Friendly Spine Surgery in Arthrogryposis Multiplex Congenita

BACKGROUND

Arthrogryposis multiplex congenita (AMC) is a condition that describes neonates born with ≥2 distinct congenital contractures. Despite spinal deformity in 3% to 69% of patients, inadequate data exist on growth-friendly instrumentation (GFI) in AMC. Our study objectives were to describe current GFI trends in children with AMC and early-onset scoliosis (EOS) and to compare long-term outcomes with a matched idiopathic EOS (IEOS) cohort to determine whether spinal rigidity or extremity contractures influenced outcomes.

METHODS

Children with AMC and spinal deformity of ≥30° who were treated with GFI for ≥24 months were identified from a multicenter EOS database (1993 to 2017). Propensity scoring matched 35 patients with AMC to 112 patients with IEOS with regard to age, sex, construct, and curve. Multivariable linear mixed modeling compared changes in spinal deformity and the 24-item Early Onset Scoliosis Questionnaire (EOSQ-24) across cohorts. Cohort complications and reoperations were analyzed using multivariable Poisson regression.

RESULTS

Preoperatively, groups did not differ with regard to age (p = 0.87), sex (p = 0.96), construct (p = 0.62), rate of nonoperative treatment (p = 0.54), and major coronal curve magnitude (p = 0.96). After the index GFI, patients with AMC had reduced percentage of coronal correction (35% compared with 44%; p = 0.01), larger residual coronal curves (49° compared with 42°; p = 0.03), and comparable percentage of kyphosis correction (17% compared with 21%; p = 0.52). In GFI graduates (n = 81), final coronal curve magnitude (55° compared with 43°; p = 0.22) and final sagittal curve magnitude (47° compared with 47°; p = 0.45) were not significantly different at the latest follow-up after definitive surgery. The patients with AMC had reduced T1-S1 length (p < 0.001), comparable T1-S1 growth velocity (0.66 compared with 0.85 mm/month; p = 0.05), and poorer EOSQ-24 scores at the time of the latest follow-up (64 compared with 83 points; p < 0.001). After adjusting for ambulatory status and GFI duration, patients with AMC developed 51% more complications (incidence rate ratio, 1.51 [95% confidence interval (CI), 1.11 to 2.04]; p = 0.009) and 0.2 more complications/year (95% CI, 0.02 to 0.33 more; p = 0.03) compared with patients with IEOS.

CONCLUSIONS

Patients with AMC and EOS experienced less initial deformity correction after the index surgical procedure, but final GFI curve magnitudes and total T1-S1 growth during active treatment were statistically and clinically comparable with IEOS. Nonambulatory patients with AMC with longer GFI treatment durations developed the most complications. Multidisciplinary perioperative management is necessary to optimize GFI and to improve quality of life in this complex population.

LEVEL OF EVIDENCE

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

Risk factors for gastrointestinal complications after spinal fusion in children with cerebral palsy

DESIGN

Prospective cerebral palsy (CP) registry review.

OBJECTIVES

(1) Evaluate the incidence/risk factors of gastrointestinal (GI) complications in CP patients after spinal fusion (SF); and (2) investigate the validity of the modified Clavien-Dindo-Sink classification.

BACKGROUND

Perioperative GI complications result in increased length of stay (LOS) and patient morbidity/mortality. However, none have analyzed the outcomes of GI complications using an objective classification system.

METHODS

A prospective/multicenter CP database identified 425 children (mean, 14.4 ± 2.9 years; range, 7.9-21 years) who underwent SF. GI complications were categorized using the modified Clavien-Dindo-Sink classification. Grades I-II were minor complications and grades III-V major. Patients with and without GI complications were compared.

RESULTS

87 GI complications developed in 69 patients (16.2%): 39 minor (57%) and 30 major (43%). Most common were pancreatitis (n = 45) and ileus (n = 22). Patients with preoperative G-tubes had 2.2 × odds of developing a GI complication compared to oral-only feeders (OR 2.2; 95% CI 0.98-4.78; p = 0.006). Similarly, combined G-tube/oral feeders had 6.7 × odds compared to oral-only (OR 6.7; 95% CI 3.10-14.66; p < 0.001). The likelihood of developing a GI complication was 3.4 × with normalized estimated blood loss (nEBL) ≥ 3 ml/kg/level fused (OR 3.41; 95% CI 1.95-5.95; p < 0.001). Patients with GI complications had more fundoplications (29% vs. 17%; p = 0.03) and longer G-tube fasting periods (3 days vs. 2 days; p < 0.001), oral fasting periods (5 days vs. 2 days; p < 0.001), ICU admissions (6 days vs. 3 days; p = 0.002), and LOS (15 days vs. 8 days; p < 0.001). LOS correlated with the Clavien-Dino-Sink classification.

CONCLUSION

Gastrointestinal complications such as pancreatitis and ileus are not uncommon after SF in children with CP. This is the first study to investigate the validity of the modified Clavien-Dindo-Sink classification in GI complications after SF. Our results suggest a correlation between complication severity grade and LOS. The complexity of perioperative enteral nutritional supplementation requires prospective studies dedicated to enteral feeding protocols.

LEVEL OF EVIDENCE

Therapeutic-level III.

Efficacy of bracing in skeletally immature patients with moderate-severe idiopathic scoliosis curves between 40° and 60°

STUDY DESIGN

Retrospective case-series.

OBJECTIVES

To evaluate the outcomes of bracing in skeletally immature patients with moderate-severe idiopathic scoliosis (IS) curves ≥ 40°.

BACKGROUND

In contrast to prior beliefs, the recent studies have reported successful outcomes with brace treatment may occur in some patients with moderate-severe scoliosis ≥ 40°. Despite other encouraging case-series, non-operative treatment is rarely attempted and the efficacy of bracing large curves remains uncertain.

METHODS

100 skeletally immature children (mean 11.8 ± 2.36 years; range 6.1-16.5) with IS ≥ 40° were identified. 80 were adolescent IS (80%) and 20 juvenile IS (20%). The Risser plus score was used to evaluate skeletal maturity. 66 children were Risser 0 (66%). SRS-SOSORT outcome guidelines were used: > 5° progression, stabilization between - 5° and 5° and, > 5° improvement.

RESULTS

Mean initial Cobb was 45° ± 3.9° (range 40°-59°), with in-brace and  % correction of 30° ± 8.7° (range 7°-48°) and 34 ± 17.5% (range 2-84%), respectively. 57 progressed (57%), 32 stabilized (32%), and 11 improved (11%) after a median of 1.8 years (IQR 1.2-2.9). Open triradiate cartilage at presentation (p = 0.005) and less in-brace correction (p = 0.009) were associated with progression. 58 children (58%) underwent surgery after a mean of 3.0 years (range 0.7-7.3). Surgical patients were younger (11.2 vs. 12.7 years; p = 0.003), more often Risser 0 (79% vs. 48%; p < 0.001); however, presented with similar curves (45° vs. 44°; p = 0.31). Open triradiate cartilage at presentation (OR 15.3; 95% CI 4.3-54.6; p < 0.001) and less in-brace correction (p = 0.03) increased the likelihood of surgery. All 20 JIS patients avoided temporary growth rods, with 18 (90%) eventually requiring surgery.

CONCLUSION

Non-operative treatment was successful in 42% of children. Risk factors for surgery were younger age, open triradiates, and less in-brace correction. Bracing can be effective in delaying surgery until skeletal maturity in patients with curves ≥ 40°. Patients should be counseled on the risks and benefits of bracing and surgery.

LEVEL OF EVIDENCE

Level IV.

Clavicular osteotomy in complicated revision of total shoulder arthroplasty: indications, surgical technique, and outcomes

PURPOSE

Adequate exposure in revision of total shoulder arthroplasty (TSA) is important for optimal prosthesis placement and functional results. A clavicular osteotomy in difficult cases of revision TSA is a useful surgical technique that increases the superior exposure area, provides safer dissection, minimizes damage to the anterior deltoid muscle, improves glenoid access, and allows for superior dislocation of the humeral component. There is a paucity of literature analyzing the clavicular osteotomy during challenging cases of revision TSA. The aims of this study were to describe the application, surgical technique, and outcomes of revision TSA with a clavicular osteotomy.

METHODS

This was a retrospective study of consecutive patients who underwent revision TSA with a clavicle osteotomy at a single institution (2004-2016). A curved longitudinal clavicular osteotomy is created parallel to the origin of the anterior deltoid muscle. This allows for lateral reflection of the osteotomy and anterior deltoid muscle to significantly increase superior exposure and reduce damage to remaining deltoid muscle fibres. Osteotomy closure is simple with four or five Nice knot osteosutures. The Constant-Murley score and osteotomy healing were assessed at every follow-up. All complications were reviewed.

RESULTS

Forty patients who had a mean age of 63.8 years (range 37-87) at time of surgery and mean follow-up duration of 34 months (range 12-88) were analyzed. Pre-operative Constant-Murley scores improved significantly from 32 ± 19.0 to 58 ± 15.0 (p < 0.001) at one year and 65 ± 13.1 (p < 0.001) at two years. Primary osteotomy healing and callus formation were evident in 95% of cases by three months. Five patients developed post-operative complications (13%) related to the clavicular osteotomy: three mid-diaphyseal clavicular fractures sustained after trauma (8%), one clavicular stress fracture (3%), and case of one loosening (3%). Three patients (8%) required surgical revision of the osteotomy (two internal fixation and one revision osteosuturing). No neurovascular injuries or scapular fractures were encountered.

CONCLUSION

A curved longitudinal clavicular osteotomy is beneficial in difficult revision TSA and is another tool in the arsenal of experienced shoulder surgeons who manage these challenging cases. This surgical technique increases glenoid exposure, facilitates superior dislocation of the humeral component, minimizes anterior deltoid damage, and reduces the risk of neurovascular injuries. All clavicular complications occurred within four months prior to osteotomy union, with many sustained due to trauma. However, patients who developed a complication had comparable shoulder function as those without.

Chiari I malformations with syringomyelia: long-term results of neurosurgical decompression

STUDY DESIGN

Retrospective case series.

OBJECTIVES

The objective was to assess the long-term outcomes on scoliosis following Chiari-I (CM-I) decompression in patients with CM-I and syringomyelia (SM). A secondary objective was to identify risk factors of scoliosis progression.

BACKGROUND

The association between CM-I with SM and scoliosis is recognized, but it remains unclear if CM-I decompression alters the long-term evolution of scoliosis in patients with associated syringomyelia.

METHODS

A retrospective review of children with scoliosis, CM-I, and SM during 1997-2015 was performed. Congenital, syndromic, and neuromuscular scoliosis were excluded. Clinical and radiographic characteristics were recorded at presentation, pre-decompression, after 1-year, and latest follow-up. A scale to measure syringomyelia area on MRI was used to evaluate SM changes post-decompression.

RESULTS

65 children with CM-I, SM, and scoliosis and a mean age of 8.9 years (range 0.7-15.8) were identified. Mean follow-up was 6.9 years (range 2.0-20.4). Atypical curves were present in 28 (43%) children. Thirty-eight patients (58%) underwent decompression before 10 years. Syringomyelia size reduced a mean of 70% after decompression (p < 0.001). Scoliosis improved in 26 (40%), stabilized in 17 (26%), and progressed in 22 (34%) cases. Early spinal fusion was required in 7 (11%) patients after a mean of 0.5 ± 0.37 years and delayed fusion in 16 (25%) patients after 6.0 ± 3.24 years. The remaining 42 (65%) patients were followed for a median of 6.1 years (range 2.0-12.3) without spine instrumentation or fusion. Fusion patients experienced less improvement in curve magnitude 1-year post-decompression (p < 0.001) and had larger curves at presentation (43° vs. 34°; p = 0.004).

CONCLUSIONS

Syringomyelia size decreased by 70% after CM-I decompression and scoliosis stabilized or improved in two-thirds of patients. Greater curve improvement within the first year post-decompression and smaller curves at presentation decreased the risk of spinal fusion. Neurosurgical decompression is recommended in children with CM-I, SM, and scoliosis with the potential to treat all three conditions.

LEVEL OF EVIDENCE

Level IV.

Halo-gravity traction for the treatment of pediatric cervical spine disorders

OBJECTIVE

Halo-gravity traction (HGT) is an effective and safe method for gradual correction of severe cervical deformities in adults. However, the literature is limited on the use of HGT for cervical spine deformities that develop in children. The objective of the present study was to evaluate the safety and efficacy of HGT for pediatric cervical spine deformities.

METHODS

Twenty-eight patients (18 females) whose mean age was 11.3 ± 5.58 years (range 2-24.9 years) underwent HGT. Common indications included kyphosis (n = 12), rotatory subluxation (n = 7), and basilar invagination (n = 6). Three children (11%) received traction to treat severe occipitocervical instability. For these 3 patients, traction combined with a halo vest, with bars attached rigidly to the vest, but with the ability to slide through the connections to the halo crown, was used to guide the corrective forces and moments in a specific and controlled manner. Patients ambulated with a wheelchair or halo walker under constant traction. Imaging was done before and during traction to evaluate traction efficacy. The modified Clavien-Dindo-Sink classification was used to categorize complications.

RESULTS

The mean duration of HGT was 25 days (IQR 13-29 days), and the mean traction was 29% ± 13.0% of body weight (IQR 19%-40% of body weight). The mean kyphosis improved from 91° ± 20.7° (range 64°-122°) to 56° ± 17.6° (range 32°-96°) during traction and corresponded to a mean percentage kyphosis correction of 38% ± 13.8% (range 21%-57%). Twenty-five patients (89%) underwent surgical stabilization, and 3 patients (11%) had rotatory subluxation that was adequately reduced by traction and were treated with a halo vest as their definitive treatment. The mean hospital stay was 35 days (IQR 17-43 days).Nine complications (32%) occurred: 8 grade I complications (28%), including 4 cases of superficial pin-site infection (14%) and 4 cases of transient paresthesia (14%). One grade II complication (4%) was seen in a child with Down syndrome and a preexisting neurological deficit; this patient developed flaccid paralysis that rapidly resolved with weight removal. Six cases (21%) of temporary neck discomfort occurred as a sequela of a preexisting condition and resolved without treatment within 24-48 hours.

CONCLUSIONS

HGT in children is safe and effective for the gradual correction of cervical kyphosis, atlantoaxial subluxation, basilar invagination, and os odontoideum. Cervical traction is an additional tool for the pediatric spine surgeon if uncertainties exist that the spinal alignment required for internal fixation and deformity correction can be safely achieved surgically. Common complications included grade I complications such as superficial pin-site infections and transient paresthesias. Halo vest gravity traction may be warranted in patients with baseline neurological deficits and severe occipitocervical instability to reduce the chance of catastrophic movement.

Perioperative acute neurological deficits in instrumented pediatric cervical spine fusions

OBJECTIVE

Pediatric cervical deformity is a complex disorder often associated with neurological deterioration requiring cervical spine fusion. However, limited literature exists on new perioperative neurological deficits in children. This study describes new perioperative neurological deficits in pediatric cervical spine instrumentation and fusion.

METHODS

A single-center review of pediatric cervical spine instrumentation and fusion during 2002-2018 was performed. Demographics, surgical characteristics, and neurological complications were recorded. Perioperative neurological deficits were defined as the deterioration of preexisting neurological function or the appearance of new neurological symptoms.

RESULTS

A total of 184 cases (160 patients, 57% male) with an average age of 12.6 ± 5.30 years (range 0.2-24.9 years) were included. Deformity (n = 39) and instability (n = 36) were the most frequent indications. Syndromes were present in 39% (n = 71), with Down syndrome (n = 20) and neurofibromatosis (n = 12) the most prevalent. Eighty-seven (48%) children presented with preoperative neurological deficits (16 sensory, 16 motor, and 55 combined deficits).A total of 178 (96.7%) cases improved or remained neurologically stable. New neurological deficits occurred in 6 (3.3%) cases: 3 hemiparesis, 1 hemiplegia, 1 quadriplegia, and 1 quadriparesis. Preoperative neurological compromise was seen in 4 (67%) of these new deficits (3 myelopathy, 1 sensory deficit) and 5 had complex syndromes. Three new deficits were anticipated with intraoperative neuromonitoring changes (p = 0.025).Three (50.0%) patients with new neurological deficits recovered within 6 months and the child with quadriparesis was regaining neurological function at the latest follow-up. Hemiplegia persisted in 1 patient, and 1 child died due a complication related to the tracheostomy. No association was found between neurological deficits and indication (p = 0.96), etiology (p = 0.46), preoperative neurological symptoms (p = 0.65), age (p = 0.56), use of halo vest (p = 0.41), estimated blood loss (p = 0.09), levels fused (p = 0.09), approach (p = 0.07), or fusion location (p = 0.07).

CONCLUSIONS

An improvement of the preexisting neurological deficit or stabilization of neurological function was seen in 96.7% of children after cervical spine fusion. New or progressive neurological deficits occurred in 3.3% of the patients and occurred more frequently in children with preoperative neurological symptoms. Patients with syndromic diagnoses are at higher risk to develop a deficit, probably due to the severity of deformity and the degree of cervical instability. Long-term outcomes of new neurological deficits are favorable, and 50% of patients experienced complete neurological recovery within 6 months.