Prevalence and Risk Factors Associated With Pelvic Rod/Screw Radiographic Lucency Following Scoliosis Surgery in Spastic Cerebral Palsy: A Longitudinal Study.

BACKGROUND: Radiographic lucency around a smooth pelvic rod (Galveston/unit rod technique) or sacroiliac/iliac screw following spinal fusion in children with nonambulatory spastic cerebral palsy (CP) has been described as a "windshield wiper" phenomenon. We evaluated demographics, radiographs, and complications in 101 cases from a single center to determine prevalence, risk factors, and complications associated with persistent radiographic lucency from 1 to 5 years following spinal fusion. METHODS: Inclusion criteria were diagnosis of nonambulatory spastic quadriplegic CP [Gross Motor Function Classification System (GMFCS) IV-V], under 18 years of age, scoliosis treated by posterior fusion from upper thoracic to sacrum with pelvic fixation (Galveston rod, iliac screw, or sacroiliac screw), adequate radiographs (preoperative, immediate postoperative, first-year, and second-year), and minimum 5-year follow-up. We evaluated demographics, radiographic parameters, comorbidities, scoliosis curve type, type of pelvic screw/rod, use of off-set connector, screw width, associated with posterior column osteotomy and/or additional anterior spinal release concurrent with posterior spine fusion, and infection over the follow-up period. Specific attention was given to the area and shape of the radiographic lucency. The logistic regression analysis was performed for continuous and categorical variables to define risk factors ( P =0.05). RESULTS: In 101 patients, data were collected at mean intervals of 1-year, 2-year, and >5-year follow-up and were 12.9±1.5, 25.8±2.5, and 81.5±23.0 months, respectively. Prevalence of pelvic rod/screw radiographic lucency was unchanged at 33%, 35%, and 24% at 1-year, 2-year, and >5-year follow-up, respectively, and radiographic parameters did not change ( P >0.05). Furthermore, no risk factors or complications were associated with radiographic lucency around pelvic rods/screws ( P >0.05). CONCLUSION: In patients with spastic nonambulatory CP who had scoliosis treated with posterior spinal fusion from upper thorax to pelvis, the prevalence of pelvic rod/screw lucency is high. Persistent lucency >2 mm around pelvic implants is not clinically significant, does not warrant advanced imaging, or indicate a complication if stable over time and wider distally than proximally. LEVEL OF EVIDENCE: Level III.

Applications and Error Ratios of Calibration Techniques in EOS, Orthoroentgenogram, and Teleoroentgenogram for Length Measurement: A Comparative Study.

BACKGROUND: Accurate length measurements of extremity bones are essential in treating limb deformities and length discrepancies in children. OBJECTIVE: This study aimed to determine errors in common techniques used to measure lower limb lengths in children. METHODS: Precision and instrument errors in length measurements were studied utilizing electro-optical system (EOS), orthoroentgenogram, and teleoroentgenogram The goal was to measure a 70-cm metallic rod phantom (average length of the lower extremity of a 10-year-old boy in the 50th percentile) in 3 phases. In Phase 1, the length measurements were performed in an EOS unit with internal calibrations, a magball/magstrip in various scan positions, and measurement with TraumaCAD software. In Phase 2, the measurements were repeated utilizing a single radiation "shot" teleoroentgenogram. In Phase 3, an orthoroentgenogram was utilized with a radiopaque ruler reference. The reliability and validity of measurements were calibrated by 4 physicians (a radiologist, senior orthopaedic attending, and 2 orthopaedic fellows). RESULTS: EOS measurements utilizing internal references had excellent accuracy (for a 700-mm real length, magnification error (ME)] of 0.09%. Teleoroentgenogram with a magball reference and measurements performed with automatic calibration by TraumaCAD program results in ME of 1.83% with insignificant intraobserver/interobserver difference. Teleoroentgenogram with a magball or magstrip reference measured manually showed that the magball has higher intraobserver/interobserver variance than magstrip, with a 6.60 and 0.33-mm SD, respectively. The length by manual measurement utilizing the magstrip has ME of 2.21%. Orthoroentgenogram is accurate with ME of 0.26%, but does not allow anatomical analysis and is also radiation-costly. CONCLUSION: EOS and orthoroentgenogram are very accurate for length measurements. Teleoroentgenogram is less accurate in measuring length; however, addition of an external reference (magball, magstrip) placed lateral to the target improves accuracy. Automatic calibration with computer-based analysis of the external reference improves the accuracy more than manual calibration. If manual calibration is utilized, the length measurement is less accurate with the magball than the magstrip. LEVEL OF EVIDENCE: Level II-comparative in vitro study.

Elongation-Derotation-Flexion Casting Treatment of Early-Onset Progressive Scoliosis in Skeletal Dysplasia.

BACKGROUND: Early-onset scoliosis in children with skeletal dysplasia is progressive, contributing to cardiopulmonary restrictive disease. Serial elongation-derotation-flexion (EDF) casting, used in other etiologies of scoliosis to delay curve progression, may be beneficial in maximizing spine growth. Our hypothesis is serial EDF casting can be safely used as a temporary alternative to surgery, delaying progression and preserving growth, to treat scoliosis in skeletal dysplasia. METHODS: All patients with skeletal dysplasia treated at a single institution with serial EDF casting for scoliosis were reviewed retrospectively. Radiographic parameters: Cobb angle of major and minor curves, curve location, thoracic height, thoracolumbar height, space available for lung, and rib vertebra angle difference were measured before casting (C1), in first casting (C2), in last casting (C3), and out of last casting (C4). Peak inspiratory pressure (PIP) values were monitored and recorded during the casting application. RESULTS: Eleven patients met the inclusion criteria (mean 9.7 castings). The mean duration of EDF serial casting was 35 months. The mean major Cobb angles were 54 degrees° (C1), 30 degrees (C2), 37 degrees (C3), and 49 degrees (C4) with no statistically significant differences. The mean minor Cobb angles were 35 degrees (C1), 25 degrees (C2), 33 degrees (C3), and 51 degrees (C4) with no statistically significant differences. The mean thoracic heights were 130 mm (C1), 155 mm (C2), 173 mm (C3), and 160 mm (C4). The 19-mm mean difference between C2 and C3 represents spinal growth. The PIP-1, PIP-2, and PIP-3 mean values were 15, 27, and 18 cmH2O, respectively. Changes in PIP-1 and PIP-2 and PIP-2 and PIP-3 were statistically significant. CONCLUSION: Serial EDF casting can delay surgical scoliosis correction in children younger than 7 years with a diagnosis of skeletal dysplasia. Our study showed that serial casting controls progression of the major curve and allows longitudinal growth of the spine with possible expansion of lung volume for nearly 3 years. During cast application, PIP increased with molding and traction, and improved until windowing and trimming of the cast. LEVEL OF EVIDENCE: Level IV-retrospective study.

Risk Factors for Failure of Pavlik Harness Treatment in Infants With Dislocated Hips That Are Evaluated by Dynamic Sonography.

BACKGROUND: Frankly dislocated hips occur in ∼1% to 3% of infants with developmental dysplasia of the hip and are often difficult to treat. In the most severely dislocated hips, the femoral head is positioned outside the posterior/lateral rim of the acetabulum and is irreducible, that is, the femoral head will not reduce by positioning the leg. The purpose of this study was to determine risk factors, using univariate and multivariate analyses, for Pavlik harness failure in infants who initially presented with irreducible/dislocated hips (confirmed by dynamic sonography). METHODS: Following institutional review board approval, 124 infants (170 hips) with frankly dislocated hips treated using a Pavlik harness between 2000 and 2018 were evaluated. Patients' demographic characteristics, clinical findings, dynamic sonographic findings (dislocated-fixed vs. dislocated-mobile), age at onset of Pavlik harness treatment, duration of harness usage, and follow-up treatments were recorded. Univariate analyses were used to determine risk factors for treatment failure. RESULTS: In frankly dislocated hips (confirmed by dynamic sonography to be positioned outside the posterior/lateral rim of the acetabulum), Pavlik harness treatment was successful in 104 of 170 hips (61%) while it failed in 66 hips. Mean follow-up was 4.86±4.20 years. Univariate analysis determined the risk factors to be onset of treatment after the seventh week of age (P=0.049) and initial mobility (dislocated-fixed group) (P<0.001) by dynamic sonography. In addition, multivariate analysis (P=0.007) showed infants of multigravida mothers (non-firstborn) to be another risk factor for failure. Six percent of hips with no risk factors failed Pavlik harness treatment, those with 1 risk factor had 42% failure, 2 risk factors had 69% failure, and all 3 risk factors had 100% failure. CONCLUSIONS: In our patients with frankly dislocated irreducible hips, 39% of hip failed Pavlik harness treatment. Independent multivariate, logistic regression analysis, and multivariate analysis determining the risk factors for failure of Pavlik harness treatment were onset of treatment after the seventh week of age, infants of multigravida mothers, and initial hip mobility (fixed-dislocated hips) by dynamic sonography. LEVEL OF EVIDENCE: Level III.

Predicting Ambulatory Function Based on Infantile Lower Extremity Posture Types in Amyoplasia Arthrogryposis.

BACKGROUND: Arthrogryposis multiplex congenita (AMC) is a nonprogressive syndrome with multiple rigid joints, fibrotic periarticular tissue, and muscular fibrosis. The most common subgroup is amyoplasia. Ambulation is one of the most significant functions of the lower extremities as it translates to increased functionality and independence in adulthood. There is no predicative scale to determine ambulation at maturity for the infant with amyoplasia. It is believed lower extremity resting position of infants with amyoplasia potentially correlates with ambulation at maturity. The purpose of this study was to classify the infantile position of lower extremities and muscle strength to predict ambulation potential at maturity. METHODS: Children with amyoplasia were retrospectively reviewed and classified into groups based on infantile position of hip-knee alignment and limb muscle function. Sitting, standing, and walking skills from infancy into adulthood were evaluated. The ambulation function was correlated with the infantile position of the lower extremities. RESULTS: Amyoplasia cases were sorted into 5 types and correlated with ambulatory potential. Type I: mild ambulatory impairment with infantile position of flexed knees and hips but full range of motion. At maturity, all were community ambulators. Type II: moderate ambulatory impairment having infantile position of hip flexion, hip external rotation, and knee flexion contractures. Hip abductors and external rotators had antigravity strength. All stood and walked during the first decade of life with knee ankle foot orthoses. Type III: severe ambulatory impairment having infantile position of hip flexion, abduction, external rotation, and knee flexion contractures but lacked hip muscle recruitment. All used wheelchairs at maturity. Type IV: mild ambulatory impairment with infantile position of extended knees and flexed dislocated hips. At maturity, 90% were community ambulators. Type V: variable ambulatory impairment having asymmetric hip and knee alignment with unilateral hip dysplasia with extended knee and opposite limb flexed. Ambulation skill varied at maturity with 27% full-time wheelchair users. CONCLUSIONS: Amyoplasia can be sorted by infantile position of lower extremities and muscle strength into 5 types to predict ambulatory function. LEVEL OF EVIDENCE: Level III-Prognostic Study.

Closed displaced femur fractures in children with nonambulatory cerebral palsy.

Femoral fractures in children withcerebral palsy (CP) represent a frequent medical problem, and treatment represents a challenge. The purpose of this study was to review the closed displaced femoral fractures in our population of nonambulatory children with CP to compare the results of nonoperative and operative treatment modalities to improve the care of these children. From 2006 to 2020, children with nonambulatory CP were selected with inclusion criteria of displaced femoral fracture and were divided into nonoperative and operative groups. Forty-four children met the inclusion criteria. The nonoperative group included 23 children and the operative group included 21 children. Mechanism of injury was unknown in 48% of the fractures. Fourteen (25%) fractures occurred after a femoral plate fixation during a reconstructive hip surgery, and 38 (86%) children had osteopenia. Our results reveal a high prevalence of osteopenia, low-energy trauma, malunion in nonoperative treatment, and peri-implant fractures. Suspicion of child abuse should be considered when the fracture has an unclear mechanism of the injury. Removal of proximal femoral implants may be considered to prevent peri-implant fractures. Femoral fractures should preferably be treated nonoperatively. Operative treatment should be considered for diaphyseal fractures in children capable of standing transfers, larger children, children with more severe spasticity or movement disorder or those who have suffered a high-energy fracture. Due to the high prevalence of proximal fractures in the presence of hardware, operative treatment is usually required for these fractures. In contrast, distal fractures are adequately managed nonoperatively.

Tension band plate-guided growth of knee-flexion deformity in arthrogryposis multiplex congenita in which metaphyseal funnelization induced screw encroachment upon the neurovascular bundle.

Knee-flexion deformity in arthrogryposis multiplex congenita is treated by serial casting into extension, distal femoral osteotomies, distal femoral-guided growth, hemiepiphysiodesis, external fixation, capsulotomy, and soft-tissue releases. We are aware of four cases treated by distal anterior femoral-guided growth with tension band plates in which an unreported complication occurred: the screws of the tension band plates penetrated the posterior cortex of the femur during remodeling with metaphyseal funnelization risking the neurovascular bundle. Inclusion criteria were cases with arthrogryposis multiplex congenita and knee-flexion deformity, treatment at our institution by distal anterior femoral-guided growth with tension band plates, and radiographic evidence of posterior cortex screw penetration during remodeling from growth. Six knees (four cases) met the inclusion criteria. The average age at the distal anterior femoral-guided growth with tension band plate operation was 5.8 years. Radiographs after 6.6 years of follow-up showed that the screws of the tension band plates, which at surgery were intrametaphyseal, had penetrated the posterior cortex of the femur. Four knees (two cases) had diffuse pain around the knee to lower leg area, and instrumentation removal alleviated the symptoms. During distal anterior femoral-guided growth with tension band plate operation for knee-flexion deformity in arthrogryposis multiplex congenita, we found that the screws of the tension band plates, which were initially located inside the metaphysis, may protrude through the posterior bone cortex during metaphyseal funnelization with growth, and may encroach upon the neurovascular tissues. Level of evidence: Level IV - case series.

Associations among slipped capital femoral epiphysis, tibia vara, and type 2 juvenile diabetes.

BACKGROUND: Clinical consequences of obesity are numerous and include slipped capital epiphysis of the femur, tibia vara, impaired mobility, insufficient muscle strength, glucose intolerance, type 2 diabetes, hyperlipidemia, nonalcoholic fatty liver disease, cholelithiasis, hypertension, sleep apnea, polycystic ovary disease, increased cardiorespiratory effort, and pseudotumor cerebri, among others. Because slipped capital femoral epiphysis, tibia vara, and type 2 diabetes are observed commonly in obese children, a degree of multiple disease occurrence in a patient would be anticipated; however, the senior author has never observed an obese adolescent who presented at the initial diagnosis with a coexistence of slipped capital femora epiphysis, tibia vara, or type 2 diabetes, so, possibly, these constellations of comorbidities may represent unique obesity phenotypes. METHODS: We reviewed the population consisting of all consecutive patients with newly diagnosed slipped capital femoral epiphysis or tibia vara from 2000 to 2006 and a selected group of patients with type 2 diabetes treated at the Alfred I. duPont Hospital for Children, Wilmington, DE. RESULTS: There were 57 cases of slipped capital femoral epiphysis, 41 cases of tibia vara, and 53 cases of type 2 diabetes. The tibia vara group had the highest body mass index (BMI; 40.81 [13.01]); the diabetes group (BMI, 35.76 [7.04]) and the slipped capital femoral epiphysis group (BMI, 29.08 [7.07]) had the lowest BMI. There was no significant difference in age at the disease onset and height between groups. There was no overlap of disease at initial presentation among slipped capital femoral epiphysis, adolescent tibia vara, and type 2 diabetes. CONCLUSIONS: We observed 3 separate obesity-related phenotypes in adolescents with no overlap of disease at initial presentation among slipped capital femoral epiphysis, adolescent tibia vara, and type 2 diabetes.

The correction of leg-length discrepancy after treatment in developmental dysplasia of the hip by using a percutaneous epiphysiodesis.

The aims of this study were to determine factors that cause a leg-length discrepancy (LLD) to the extent that correction is indicated after treatment in developmental dysplasia of the hip and determine whether the LLD may be treated with a percutaneous epiphysiodesis. Twelve children were included in this study. The factors which caused LLD were avascular necrosis, femoral shortening and varus at reduction, and septic arthritis. Percutaneous epiphysiodesis of the contralateral limb reduced the mean predicted LLD from 3.8 to 1.2 cm at maturity. We concluded that LLD (>2.5 cm) might result from complications of developmental dysplasia of the hip and these patients can be treated with a percutaneous epiphysiodesis.