Perioperative Complications and Health-related Quality of Life Outcomes in Severe Pediatric Spinal Deformity.

STUDY DESIGN: Prospective multicenter cohort study. OBJECTIVE: To evaluate perioperative complications and mid-term outcomes for severe pediatric spinal deformity. SUMMARY OF BACKGROUND DATA: Few studies have evaluated the impact of complications on health-related quality of life (HRQoL) outcomes in severe pediatric spinal deformity. METHODS: Patients from a prospective, multicenter database with severe pediatric spinal deformity (minimum of 100 degree curve in any plane or planned vertebral column resection (VCR)) with a minimum of 2-years follow-up were evaluated (n=231). SRS-22r scores were collected preoperatively and at 2-years postoperatively. Complications were categorized as intraoperative, early postoperative (within 90-days of surgery), major, or minor. Perioperative complication rate was evaluated between patients with and without VCR. Additionally, SRS-22r scores were compared between patients with and without complications. RESULTS: Perioperative complications occurred in 135 (58%) patients, and major complications occurred in 53 (23%) patients. Patients that underwent VCR had a higher incidence of early postoperative complications than patients without VCR (28.9% vs. 16.2%, P =0.02). Complications resolved in 126/135 (93.3%) patients with a mean time to resolution of 91.63 days. Unresolved major complications included motor deficit (n=4), spinal cord deficit (n=1), nerve root deficit (n=1), compartment syndrome (n=1), and motor weakness due to recurrent intradural tumor (n=1). Patients with complications, major complications, or multiple complications had equivalent postoperative SRS-22r scores. Patients with motor deficits had lower postoperative satisfaction subscore (4.32 vs. 4.51, P =0.03), but patients with resolved motor deficits had equivalent postoperative scores in all domains. Patients with unresolved complications had lower postoperative satisfaction subscore (3.94 vs. 4.47, P =0.03) and less postoperative improvement in self-image subscore (0.64 vs. 1.42, P =0.03) as compared to patients with resolved complications. CONCLUSION: Most perioperative complications for severe pediatric spinal deformity resolve within 2-years postoperatively and do not result in adverse HRQoL outcomes. However, patients with unresolved complications have decreased HRQoL outcomes.

Developing consensus for the management of pediatric cervical spine disorders and stabilization: a modified Delphi study.

OBJECTIVE: Cervical spine disorders in children are relatively uncommon; therefore, paradigms for surgical and nonsurgical clinical management are not well established. The purpose of this study was to bring together an international, multidisciplinary group of pediatric cervical spine experts to build consensus via a modified Delphi approach regarding the clinical management of children with cervical spine disorders and those undergoing cervical spine stabilization surgery. METHODS: A modified Delphi method was used to identify consensus statements for the management of children with cervical spine disorders requiring stabilization. A survey of current practices, supplemented by a literature review, was electronically distributed to 17 neurosurgeons and orthopedic surgeons experienced with the clinical management of pediatric cervical spine disorders. Subsequently, 52 summary statements were formulated and distributed to the group. Statements that reached near consensus or that were of particular interest were then discussed during an in-person meeting to attain further consensus. Consensus was defined as ≥ 80% agreement on a 4-point Likert scale (strongly agree, agree, disagree, strongly disagree). RESULTS: Forty-five consensus-driven statements were identified, with all participants willing to incorporate them into their practice. For children with cervical spine disorders and/or stabilization, consensus statements were divided into the following categories: A) preoperative planning (12 statements); B) radiographic thresholds of instability (4); C) intraoperative/perioperative management (15); D) postoperative care (11); and E) nonoperative management (3). Several important statements reaching consensus included the following recommendations: 1) to obtain pre-positioning baseline signals with intraoperative neuromonitoring; 2) to use rigid instrumentation when technically feasible; 3) to provide postoperative external immobilization for 6-12 weeks with a rigid cervical collar rather than halo vest immobilization; and 4) to continue clinical postoperative follow-up at least until anatomical cervical spine maturity was reached. In addition, preoperative radiographic thresholds for instability that reached consensus included the following: 1) translational motion ≥ 5 mm at C1-2 (excluding patients with Down syndrome) or ≥ 4 mm in the subaxial spine; 2) dynamic angulation in the subaxial spine ≥ 10°; and 3) abnormal motion and T2 signal change on MRI seen at the same level. CONCLUSIONS: In this study, the authors have demonstrated that a multidisciplinary, international group of pediatric cervical spine experts was able to reach consensus on 45 statements regarding the management of pediatric cervical spine disorders and stabilization. Further study is required to determine if implementation of these practices can lead to reduced complications and improved outcomes for children.

Reoperations after primary and revision lumbar discectomy: study of a national-level cohort with eight years follow-up.

BACKGROUND CONTEXT: Published rates for disc reherniation following primary discectomy are around 6%, but the ultimate reoperation outcomes in patients after receiving revision discectomy are not well understood. Additionally, any disparity in the outcomes of subsequent revision discectomy (SRD) versus subsequent lumbar fusion (SLF) following primary/revision discectomy remains poorly studied. PURPOSE: To determine the 8-year SRD/SLF rates and time until SRD/SLF after primary/revision discectomy respectively. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Patients undergoing primary or revision discectomy, with records in the PearlDiver Patient Records Database from the years 2010 to 2019. OUTCOME MEASURES: Subsequent surgery type and time to subsequent surgery. METHODS: Patients were grouped into primary or revision discectomy cohorts based off of the nature of "index" procedure (primary or revision discectomy) using ICD9/10 and CPT procedure codes from 2010 to 19 insurance data sets in the PearlDiver Patient Records Database. Preoperative demographic data was collected. Outcome measures such as subsequent surgery type (fusion or discectomy) and time to subsequent surgery were collected prospectively in PearlDiver Mariner database. Statistical analysis was performed using BellWeather statistical software. A Kaplan-Meier survival analysis of time to SLF/SRD was performed on each cohort, and log-rank test was used to compare the rates of SLF/SRD between cohorts. RESULTS: A total of 20,147 patients were identified (17,849 primary discectomy, 2,298 revision discectomy). The 8-year rates of SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01) and SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) were higher after revision versus primary discectomy. Time to SLF was shorter after revision versus primary discectomy (709 vs. 886 days, p<.01). After both primary and revision discectomy, the 8-year rate of SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) is greater than SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01). CONCLUSIONS: Compared to primary discectomy, revision discectomy has higher rates of SLF (10.4% vs. 6.2%), and faster time to SLF (2.4 vs. 1.9 years) at 8-year follow up.

Mechanical Analysis of 3 Posterior Fusion Assemblies Intended to Cross the Cervicothoracic Junction.

STUDY DESIGN: This was a biomechanical comparison study. OBJECTIVE: The objective of this study is to evaluate the mechanical properties of 3 posterior spinal fusion assemblies commonly used to cross the cervicothoracic junction. SUMMARY OF BACKGROUND: When posterior cervical fusions are extended into the thoracic spine, an instrumentation transition is often utilized. The cervical rod (3.5 mm) can continue using thoracic screws designed to accept the cervical rods. Alternatively, traditional thoracic screws may be used to accept thoracic rods (5.5 mm). This requires the use of a 3.5-5.5 mm transition rod or a separate 5.5 mm rod and a connector to fix the 3.5 and 5.5 mm rod together. Fusion success depends on the immobilization of vertebrae, yet the mechanics provided by these different assemblies are unknown. MATERIALS AND METHODS: Three titanium alloy posterior fusion assemblies intended to cross the cervicothoracic junction underwent static compressive bending, tensile bending, and torsion as described in ASTM F1717 to a torque of 2.5 Nm. Five samples of each assembly were attached to ultrahigh molecular weight polyethylene blocks via multiaxial screws for testing. Force and displacement were recorded, and the stiffness of each construct was calculated. RESULTS: The 2 assemblies that included a 5.5 mm rod were found to be stiffer and have less range of motion than the assembly that used only 3.5 mm rods. CONCLUSIONS: The results of this study indicate that incorporating a 5.5 mm rod in a fusion assembly adds significant stiffness to the construct. When the stability of a fusion is of heightened concern, as demonstrated by the ASTM F1717 vertebrectomy (worst-case scenario) model, including 5.5 mm rods may increase fusion success rates. LEVEL OF EVIDENCE: Level V.

Alvimopan for the reduction of postoperative ileus after long posterior spinal fusion: placebo-controlled double-blind randomized trial.

OBJECTIVE: The aim of this study was to evaluate the efficacy of alvimopan administration after posterior spinal fusion (PSF) in adult spine surgery patients who are taking opioid agents. METHODS: In this placebo-controlled, double-blind randomized trial, PSF patients were randomized in blocks to placebo or study drug. Primary and secondary outcome measures were return to normal bowel function, including time to passage of flatus and stool, time to tolerance of oral nutrition, and time to hospital discharge. Patients were included regardless of chronic opioid consumption status. RESULTS: Thirty-one patients provided consent for participation, and 26 patients (13 per group) completed the study. There were no differences between groups with respect to time to flatus, time to bowel movement, time to oral nutrition tolerance, and time to discharge. Calculated effect sizes favored placebo for all interventions. CONCLUSIONS: Alvimopan did not hasten return to bowel function for any primary or secondary outcome measures when compared with placebo for patients undergoing PSF. There were no adverse events related to alvimopan, including for patients with chronic opioid consumption. While underpowered to determine a statistical difference, it is unlikely that a clinically relevant effect exists.

The Hip and Femur Fracture Bundle: Preliminary Findings From a Tertiary Hospital.

BACKGROUND: The voluntary hip and femur fracture Bundled Payments for Care Improvement Advanced (BCPI-A) includes Diagnosis Related Groups (DRG) 480, 481, and 482, which include diverse and medically complex patients undergoing urgent inpatient surgery without optimization. Concern exists that this bundle is financially unfavorable for hospitals, and this study aimed to identify the costliest services. METHODS: We retrospectively reviewed a 12-month cohort of 32 consecutive patients in the DRG 480-482 bundle at our academic tertiary referral center. Cost of discharge disposition, readmission, and other variables were analyzed for all patients in the 90-day bundle. RESULTS: Overall, a net financial gain averaging $2,028 per patient (range -$52,128 to +$30,199) was seen. Discharge to facilities (n = 19) resulted in higher costs than discharge to home (n = 11, P < .0001). Use of inpatient rehabilitation (n = 6) averaged a loss of $11,028 per patient and use of skilled nursing facilities (n = 15) averaged a loss of $7,250 per patient, compared to a gain of $15,011 for patients discharged home (n = 11). Episodes with readmission (n = 6) averaged a loss of only $1,390. Total index admission costs averaged $12,489 ± $2,235 per patient (range $9,329-$18,884) while post-inpatient cost averaged $30,150 per patient (range $4,803 - $77,768). CONCLUSION: The BPCI-A hip and femur fracture bundle has a wide variability in costs, with the largest component in the post-acute care phase. Discharge home is favorable in the bundle while discharge to post-acute facilities leads to net losses. Institutions in this bundle need to develop multi-disciplinary teams to promote safe discharge home.

Changes in kinematics, kinetics, and muscle activity in patients with lumbar spinal stenosis during gait: systematic review.

BACKGROUND CONTEXT: Lumbar spinal stenosis (LSS) is one of the most common orthopaedic conditions and affects more than half a million people over the age of 65 in the US. Patients with LSS have gait dysfunction and movement deficits due to pain and symptoms caused by compression of the nerve roots within a narrowed spinal canal. PURPOSE: The purpose of the current systematic review was to summarize existing literature reporting biomechanical changes in gait function that occur with LSS, and identify knowledge gaps that merit future investigation in this important patient population. STUDY DESIGN/SETTING: This study is a systematic literature review. OUTCOME MEASURES: The current study included biomechanical variables (e.g., kinematic, kinetic, and muscle activity parameters). METHODS: Relevant articles were selected through MEDLINE, Scopus, Embase, and Web of Science. Articles were included if they: 1) included participants with LSS or LSS surgery, 2) utilized kinematic, kinetic, or muscle activity variables as the primary outcome measure, 3) evaluated walking or gait tasks, and 4) were written in English. RESULTS: A total of 11 articles were included in the current systematic review. The patients with LSS exhibited altered gait function as compared to healthy controls. Improvements in some biomechanical variables were found up to one year after surgery, but most gait changes were found within one month after surgery. CONCLUSIONS: Although numerous studies have investigated gait function in patients with LSS, gait alterations in joint kinetics and muscle activity over time remain largely unknown. In addition, there are limited findings of spinal kinematics in patients with LSS during gait. Thus, future investigations are needed to investigate longer-term gait changes with regard to spinal kinematics, joint kinetics, and muscle activity beyond one month after LSS surgery.

Infant inclined sleep product safety: A model for using biomechanics to explore safe infant product design.

Over 450 adverse incidents have been reported in infant inclined sleep products over the past 17 years, with many infants found dead in both the supine and prone positions. The unique design of inclined sleep products may present unexplored suffocation risks related to how these products impact an infant's ability to move. The purpose of this study was to assess body movement and muscle activity of healthy infants when they lie supine and prone on different inclined sleep products. Fifteen healthy full-term infants (age: 17.7 ±â€¯4.9 weeks) were recruited for this IRB-approved study. Three inclined sleep products with unique features, representative of different sleeper designs, were included. Surface electromyography (EMG) was recorded from infants' cervical paraspinal, abdominal, and lumbar erector spinae muscles for 60 s during supine and prone positioning. Neck and trunk sagittal plane movements were evaluated for each testing condition. Paired t-tests and Wilcoxon signed-rank tests were performed to compare each inclined sleeper to a flat crib mattress (0° baseline condition). During prone positioning, abdominal muscle activity significantly nearly doubled for all inclined sleep products compared to the flat crib mattress, while erector spinae muscle activity decreased by up to 48%. Trunk movement significantly increased compared to the flat crib mattress during prone lying. During prone lying, inclined sleep products resulted in significantly higher muscle activity of the trunk core muscles (abdominals) and trunk movement, which has the potential to exacerbate fatigue and contribute to suffocation if an infant cannot self-correct to the supine position.

Surgical Outcomes of Obese Patients With Adolescent Idiopathic Scoliosis From Endemic Areas of Obesity in the United States.

BACKGROUND: Obesity rates continue to rise among children and adolescents across the globe. A multicenter research consortium composed of institutions in the Southern US, located in states endemic for childhood obesity, was formed to evaluate the effect of obesity on pediatric musculoskeletal disorders. This study evaluates the effect of body mass index (BMI) percentile and socioeconomic status (SES) on surgical site infections (SSIs) and perioperative complications in patients with adolescent idiopathic scoliosis (AIS) treated with posterior spinal fusion (PSF). METHODS: Eleven centers in the Southern US retrospectively reviewed postoperative AIS patients after PSF between 2011 and 2017. Each center contributed data to a centralized database from patients in the following BMI-for-age groups: normal weight (NW, 5th to <85th percentile), overweight (OW, 85th to <95th percentile), and obese (OB, ≥95th percentile). The primary outcome variable was the occurrence of an SSI. SES was measured by the Area Deprivation Index (ADI), with higher scores indicating a lower SES. RESULTS: Seven hundred fifty-one patients were included in this study (256 NW, 235 OW, and 260 OB). OB and OW patients presented with significantly higher ADIs indicating a lower SES (P<0.001). In addition, SSI rates were significantly different between BMI groups (0.8% NW, 4.3% OW, and 5.4% OB, P=0.012). Further analysis showed that superficial and not deep SSIs were significantly different between BMI groups. These differences in SSI rates persisted even while controlling for ADI. Wound dehiscence and readmission rates were significantly different between groups (P=0.004 and 0.03, respectively), with OB patients demonstrating the highest rates. EBL and cell saver return were significantly higher in overweight patients (P=0.007 and 0.002, respectively). CONCLUSION: OB and OW AIS patients have significantly greater superficial SSI rates than NW patients, even after controlling for SES. LEVEL OF EVIDENCE: Level III.

Delayed diagnosis of a flexion-distraction spinal injury and occult small bowel injury in a pediatric trauma patient: Importance of recognizing the abdominal "seatbelt sign".

Spine trauma in the pediatric population can present with occult spinal and visceral injuries, presenting unique diagnostic challenges. Subtle imaging findings, as well as difficulty in patient participation with history and examination can contribute to a delayed or missed diagnosis. This in turn can be detrimental to recovery, leading to significant delay in care, additional morbidity, and cost. We present the case of an 11-year-old female patient with a delayed diagnosis of an unstable three-column lumbar spine injury as well as an occult small bowel injury that evaded diagnosis despite multiple hospitalizations and a plethora of imaging and treatment modalities. This led to several extended hospital stays and numerous interventions and surgeries to treat her injuries. We present this case to highlight the sequela of such an injury, and to broaden awareness across specialties of an injury pattern which requires a heightened index of suspicion to detect.

The Alpha-Defensin Prosthetic Joint Infection Test Has Poor Validity for Native Knee Joint Infection.

BACKGROUND: The alpha-defensin test known as Synovaure has been very effective in diagnosis of prosthetic joint infections (PJIs). Being able to easily and accurately differentiate septic and inflammatory arthropathies in native joints would improve diagnostic workup and management. We tested the ability of an alpha-defensin test to distinguish septic from inflammatory or crystalline arthropathy in the native knee. METHODS: 40 native knee joint fluid specimens were tested with cell count, fluid analysis, and culture and alpha-defensin testing. We determined the sensitivity and specificity of the alpha-defensin test using culture-positive fluid as the gold standard for septic arthropathy and positive crystals as the gold standard for crystalline arthropathy. RESULTS: The Synovasure PJI test had 100% specificity for septic arthritis coupled with a 28% false-positive rate when applied to native knee aspirations. False-positive rate was 5.3 times higher in patients with crystals found in the joint fluid. CONCLUSION: Alpha-defensin testing, in the form of the Synovasure PJI test, has a high-false-positive rate when used to distinguish septic and inflammatory arthritis in the native knee joint. Future work will need to determine the sensitivity and specificity of the newer native joint panel. Clinicians should be cognizant of the specific alpha-defensin test used when sampling native knee synovial fluid.

Do inclined sleeping surfaces impact infants' muscle activity and movement? A safe sleep product design perspective.

The design of inclined sleep products may be associated with an increased risk of suffocation when an infant finds themselves prone in the product. It is important to understand how different inclined sleep surface angles impact infants' muscle activity when considering a safe sleep environment. The purpose of this study was to assess muscle activity of healthy infants when they lie supine and prone on different inclined crib mattress surfaces (0° vs. 10° vs. 20°). Fifteen healthy infants were recruited for this study. Surface EMG was recorded from cervical paraspinal, abdominal, lumbar erector spinae, and triceps muscles for 60 s during supine and prone positioning. Repeated measures ANOVAs and Bonferroni post-hoc adjustments were performed to test the effect of incline angles. Paired t-tests were performed to test the effect of position (supine vs. prone). During prone lying, abdominal muscle activity increased by 33% and 71% for 10° and 20° compared to 0°, while erector spinae and triceps muscle activity decreased for 20° compared to 0°. Lumbar erector spinae and cervical paraspinal muscle activity increased by 185% and 283% for prone compared to supine lying. During prone positioning, the 20° inclined surface resulted in significantly higher muscle activity of the trunk core muscles (abdominals), which may exacerbate fatigue and contribute to suffocation if an infant cannot self-correct to the supine position. Compared to supine positioning, prone lying requires higher musculoskeletal effort to maintain a safe posture to prevent suffocation, and babies likely fatigue faster when lying prone.

Infant carrying method impacts caregiver posture and loading during gait and item retrieval.

BACKGROUND: Human babies are carried by their caregivers during infancy, and the use of ergonomic aids to wear the baby on the body has recently grown in popularity. However, the effects of wearing or holding a baby in-arms on an individual's mechanics during gait and a common object retrieval task are not fully understood. RESEARCH QUESTION: What are the differences in: 1) spatiotemporal, lower extremity kinematics, and ground reaction force variables during gait, and 2) technique, center of mass motion, and kinematics during an object retrieval task between holding and wearing an infant mannequin? METHODS: In this prospective biomechanics study, 10 healthy females performed over-ground walking and an object retrieval task in three conditions, holding: (1) nothing (unloaded), (2) an infant mannequin in-arms, and (3) an infant mannequin in a baby carrier. Mechanics were compared using repeated measures ANOVA. RESULTS: During gait, greater vertical ground reaction force and impulse and braking force was found during the in-arms and carrier conditions compared to unloaded. Significant but small (<5°) differences were found between conditions in lower extremity kinematics. Increased back extension was found during carrier and in-arms compared to unloaded. Step length was the only spatiotemporal parameter that differed between conditions. During object retrieval, most participants used a squatting technique to retrieve the object from the floor. They maintained a more upright posture, with less trunk flexion and anteroposterior movement of their center of mass, and also did not try to fold forward over their hips during the two loaded conditions. Lower extremity kinematics did not differ between unloaded and carrier, suggesting that babywearing may promote more similar lower extremity mechanics to not carrying anything. SIGNIFICANCE: Holding or wearing an infant provides a mechanical constraint that impacts the forces and kinematics, which has implications for caregivers' pain and dysfunction.

Accuracy of the Spinal Pain Diagram Is Influenced by Patient Health Literacy in Completion of the Scoliosis Research Society30 Questionnaire.

The Scoliosis Research Society Questionnaire (SRS30) was designed to measure healthrelated quality of life in scoliosis patients. Patients with low health literacy may need specific guidance when providing feedback on the SRS30 so that reliable and valid results are collected for clinical decision making. The purpose of this research study was to investigate the health literacy demands of the Scoliosis Research Society Questionnaire (SRS30) and to determine if health literacy best practices mitigate errors for patients with low health literacy. Readability assessment, focus groups and structured interviews were used. Results indicated that patients with low health literacy perceived health literacy best practices as helpful in completing the SRS30 drawing. Additionally, patients with inadequate health literacy had a higher proportion of errors in pain location on the drawing (p = 0.0325) compared to patients with adequate health literacy. (Journal of Surgical Orthopaedic Advances 29(1):3942, 2020).

Positioning and baby devices impact infant spinal muscle activity.

Infant positioning in daily life, particularly in relation to active neck and back muscles, may affect spinal development, psychosocial progression, and motor milestone achievement. Yet the impact of infant body position on muscle activity is unknown. The objective of this study was to evaluate neck and back muscle activity of healthy infants in common positions and baby devices. Healthy full-term infants (n = 22, 2-6 months) participated in this experimental study. Daily sleep and positioning were reported by caregivers. Cervical paraspinal and erector spinae muscle activity was measured using surface electromyography (EMG) in five positions: lying prone, lying supine, held in-arms, held in a baby carrier, and buckled into a car seat. Mean filtered EMG signal and time that muscles were active were calculated. Paired t-tests were used to compare positions to the prone condition. Caregivers reported that infants spent 12% of daily awake time prone, 43% in supine-lying baby gear, and 44% held in-arms or upright in a baby carrier. Infants exhibited highest erector spinae activity when prone, and lowest cervical paraspinal muscle activity in the car seat. No differences were found between in-arms carrying and babywearing. This first evaluation of the muscle activity of healthy infants supports the importance of prone time in infants' early spinal development because it promotes neck and back muscle activity. Carrying babies in-arms or in baby carriers may also be beneficial to neck muscle development, while prolonged time spent in car seats or containment devices may be detrimental to spinal development.

Validation of a custom spine biomechanics simulator: A case for standardization.

Mechanical testing machines used in cadaveric spine biomechanics research vary between labs. It is a necessary first step to understand the capabilities and limitations in any testing machine prior to publishing experimental data. In this study, a reproducible protocol that uses a synthetic spine was developed and used to quantify the inherent rotation error and the ability to apply loads in a single physiologic plane (pure-moment) of a custom spine biomechanics simulator. Rotation error was evaluated by comparing data collected by the test machine and the data collected by an optical motion capture system. Pure-moment loading was assessed by comparing the out-of-plane loads to the primary plane load. Using synthetic functional spine units previously shown to have mechanics similar to the cadaveric human spine, the simulator was evaluated using a dynamic test protocol reflective of its future use in the study of cadaveric spine specimens. Rotation errors inherent in the test machine were <0.25° compared to motion capture. Out of plane loads were <4.0% of the primary plane load, which confirmed pure-moment loading. The authors suggest that a standard validation protocol for biomechanical spine testing machines is needed for transparency and accurate field-wide data interpretation and comparison. We offer recommendations based on the reproducible use of a synthetic spinal specimen for consideration.

Curve Modulation and Apex Migration Using Shilla Growth Guidance Rods for Early-onset Scoliosis at 5-Year Follow-up.

BACKGROUND: The Shilla procedure was designed to correct and control early-onset spinal deformity while harnessing a child's remaining spinal growth. It allows for controlled axial skeletal growth within the construct, avoiding the need for frequent surgeries to lengthen implants. We hypothesized that curve characteristics evolve over time after initial apex fusion and placement of the Shilla implants. The purpose of this study was to identify trends in curve evolution after Shilla implantation and understand how these changes influence ultimate outcome. METHODS: A single-center, retrospective review of all patients with Shilla implants in place for ≥5 years yielded 21 patients. Charts and radiographs were reviewed to compare coronal curve characteristics preoperatively, postoperatively, and at last follow-up to note changes in the apex of the primary curve. Also noted were the development of adjacent compensatory curves, the overall vertical spinal growth, and the need for definitive spinal fusion once skeletal maturity was reached. RESULTS: Of the 21 patients, the curve apex migrated caudally in 12 patients (57%) and cephalad in 1 patient (5%), with a mean migration of 2.7 vertebral levels. Two patients (10%) developed new, significant compensatory curves (1 caudal and 1 cephalad). All patients demonstrated spinal growth in T1-S1 length following index surgery (mean, 45 mm). At skeletal maturity, 10 patients underwent definitive posterior spinal fusion and instrumentation, and 3 underwent implant removal alone. CONCLUSIONS: This study constitutes the longest follow-up of Shilla patients evaluating curve and implant behavior. Results of this review suggest that the apex of the fused primary curve shifts in approximately 62% of patients, with nearly all of these (92%) involving a distal migration. Compensatory curves did develop after Shilla placement as well. Overall, these findings represent adding-on distal to the apex after Shilla instrumentation rather than a crankshaft phenomenon about the apex. A better understanding of spinal growth mechanics and outcomes after Shilla placement may improve our ability to appropriately select patients and instrumentation levels. LEVEL OF EVIDENCE: Level III.

Outcomes and cost-minimization analysis of cement spacers versus expandable cages for posterior-only reconstruction of metastatic spine corpectomies.

BACKGROUND: Reconstruction of the thoracolumbar spine after tumor corpectomy can be accomplished using either an expandable metallic cage (EC) or a polymethylmethacrylate (PMMA) cement spacer. Few studies have compared the relative successes between these two forms of reconstructions in the management of metastatic spine disease (MSD). The purpose of this study was to compare both the outcomes and costs of EC and PMMA spacers in the treatment of MSD. We hypothesized that the rate of complications and revision surgery when using PMMA spacers to reconstruct the spine after corpectomy for MSD would be equivalent to use of an EC, with lower implant and operating room (OR) costs. METHODS: A single surgeon performed 65 vertebral corpectomies for MSD requiring anterior column reconstruction from 2007-2014. Charts were retrospectively reviewed and no patients were excluded. All resections were single-stage resections/reconstructions of the vertebral body through a posterior-only approach. Outcomes evaluated included perioperative complications, intraoperative time, postoperative survival, subsequent reoperations, and changes in radiographic spinal alignment. RESULTS: Thirty-six patients were treated with PMMA spacers; 29 were treated with EC. Baseline age, BMI, comorbidities, and disease severity as measured by Tokuhashi scores were equivalent between treatment groups. The cohorts had no significant differences in operative complications, blood loss, postoperative survival, number of subsequent reoperations, or changes in radiographic alignment. PMMA patients had a significantly shorter mean operative duration (328.6 vs. 241.1 min, P<0.001). Institutional implant cost savings were $4,355 favoring the PMMA cohort ($75 for cement vs. $5,000 for cage). Mean OR time savings were calculated to be $2,001 less for the PMMA cohort. Total cost minimization per PMMA case was thus $6,356, which was robust in 2-way sensitivity analyses varying both implant costs and time costs by 30%. CONCLUSIONS: In the largest series of posterior-only corpectomies for MSD reconstructed with PMMA, PMMA intervertebral spacers provided equivalent stability and longevity to EC, at a fraction of the cost. PMMA showed excellent durability while minimizing costs by $6,356 per case, an important consideration as reimbursement pressures increasingly influence surgical decision making.

Expansion Thoracoplasty as a Life-Saving Procedure in an Adolescent With Severe Spinal Deformity and Sacral Agenesis.

STUDY DESIGN: Case report. OBJECTIVES: To describe use of expansion thoracoplasty (ET) for severe thoracic insufficiency syndrome (TIS) in an adolescent with severe spinal deformity. BACKGROUND: ET is typically performed in young patients with TIS to increase chest cavity volume, improve alveolar expansion, and potentially improve alveolar proliferation. ET has not been well-described in adolescent patients with TIS. METHOD: A mature adolescent with previously treated myelokyphosis and sacral agenesis developed severe TIS with dependence on supplemental oxygen and noninvasive ventilation. She was treated with two-stage bilateral ET and vertical expandable prosthetic titanium rib (VEPTR) placement. Yearly pulmonary function testing (PFT) was performed over 7 years of follow-up. RESULTS: Significant clinical pulmonary improvement was achieved and maintained at final follow-up, as the patient no longer required supplemental oxygen. Percentage predicted forced vital capacity (FVC) improved from 29% to 36%; percentage predicted forced expiratory volume-1 second (FEV1) improved from 30% to 36%. CONCLUSIONS: This case demonstrates that improvement and stabilization of respiratory function can be achieved with instrumented ET in a skeletally mature adolescent with severe TIS and spinal deformity.

Key Role of Preoperative Recumbent Films in the Treatment of Severe Sagittal Malalignment.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine if severe sagittal malalignment (SM) patients without fixed deformities require a three-column osteotomy (3CO) to achieve favorable clinical and radiographic outcomes. SUMMARY OF BACKGROUND DATA: 3CO performed for severe SM has significantly increased in the last 15 years. Not all severe SM patients require a 3CO. METHODS: Severe SM patients (sagittal vertical axis [SVA] >10 cm) who underwent deformity correction between 2002 and 2011. Patients with <33% change in their lumbar lordosis (LL) on a preoperative supine radiograph were classified as stiff deformities, whereas those with ≥33% change were categorized as flexible deformities. The clinical/radiographic outcomes were assessed at minimum two years postoperatively. RESULTS: Seventy patients met the inclusion criteria, 35 patients with flexible and 35 with stiff deformities. Eighteen flexible-deformity patients underwent a 3CO versus 22 stiff-deformity patients. The remaining patients in each group underwent spinal realignment without a 3CO. The flexible-deformity patients not undergoing a 3CO had overall improvement in all sagittal radiographic parameters. Preoperative LL (22°), LL-pelvic incidence (PI) mismatch (43), SVA (17 cm), and pelvic tilt (PT, 34°) improved to 46°, 18, 6 cm, and 26°, respectively, p < .05. Flexible-deformity patients who underwent a 3CO also had overall improvement in all radiographic parameters. Preoperative LL (8.5°), LL-PI mismatch (47), SVA (19 cm), and PT (37°) improved to 39°, 15, 7 cm, and 24°, respectively (p < .05). Stiff-deformity patients who underwent a 3CO had statistically significant improvement in all radiographic parameters. However, stiff-deformity patients who did not undergo a 3CO had suboptimal improvement in all radiographic parameters, except for SVA (14 cm-9 cm, p < .05). Flexible patients who did not undergo a 3CO had statistical improvement in the SRS domains of function and self-mage as well as in their ODI scores (p < .05). CONCLUSION: Severe SM that is flexible can be corrected without a 3CO without compromising clinical and radiographic outcomes. LEVEL OF EVIDENCE: Level III.