Kenneth J. Rogers

Outcome of in situ pinning in patients with unstable slipped capital femoral epiphysis: assessment of risk factors associated with avascular necrosis.

Introduction Avascular necrosis (AVN) is a devastating complication following treatment of unstable slipped capital femoral epiphysis (SCFE). The advent of newer methods such as open reduction and surgical dislocation of the hip has increased the debate on the optimal method of treatment. However, the risk or predisposing factors for AVN remain unclear. We aimed to assess the outcome of in situ fixation and the risk factors associated with AVN. Methods We retrospectively reviewed the records of 27 patients (27 hips) with unstable SCFE out of the 280 children managed for SCFE from 1995 to 2006. The mean age in years of the patients at surgery was 12.2±1.58, and our sample comprised 70.4% males, and 29.6% females, with a mean follow-up of 3.1±1.9 years. Univariable and multivariable binomial regression models were used to assess factors predisposing to AVN. Results AVN occurred in 22.2% (6/27) of the children with unstable SCFE. After adjustment for age, race, and time to surgery, sex and preoperative slip angle were the only 2 significant factors related to an increased risk of AVN, risk ratio (RR)=4.15, 95% confidence interval=1.00-17.19, P=0.05 and RR=1.04, 95% confidence interval=1.00-1.07, P=0.03, respectively. Female children constitute a high-risk group for AVN in this subgroup. Conclusions AVN is still prevalent among patients with unstable SCFE who underwent in situ pinning. Female sex and slip magnitude are potential predisposing factors for developing AVN. Level of Evidence Level III (retrospective cohort study).

Long-term outcome of reconstruction of the hip in young children with cerebral palsy

We reviewed the long-term radiological outcome, complications and revision operations in 19 children with quadriplegic cerebral palsy and hip dysplasia who underwent combined peri-iliac osteotomy and femoral varus derotation osteotomy. They had a mean age of 7.5 years (1.6 to 10.9) and comprised 22 hip dislocations and subluxations. We also studied the outcome for the contralateral hip. At a mean follow-up of 11.7 years (10 to 15.1) the Melbourne cerebral palsy (CP) hip classification was grade 2 in 16 hips, grade 3 in five, and grade 5 in one. There were five complications seen in four hips (21%, four patients), including one dislocation, one subluxation, one coxa vara with adduction deformity, one subtrochanteric fracture and one infection. A recurrent soft-tissue contracture occurred in five hips and ten required revision surgery. In pre-adolescent children with quadriplegic cerebral palsy good long-term outcomes can be achieved after reconstruction of the hip; regular follow-up is required.

The lower extremity in Morquio syndrome.

Background: The modalities and results of surgical intervention in the lower extremity in children with Morquio syndrome type A [mucopolysaccharidosis-IV (MPS-IVA)] have not been well described. The aims of this study are to define the lower extremity deformities, and describe the results of intervention in MPS-IVA patients. Methods: Retrospective chart and radiograph review of 23 MPS-IVA patients with a minimum follow-up of >2 years. Patients were divided into no intervention and surgical groups. Demographic data, surgical details, clinical results, and complications were recorded. Standard lower extremity radiographic measurements made on standing radiographs at initial presentation, preoperatively (in surgical group), and at the final follow-up were used to study the deformities and effects of hip, knee, and ankle surgery. Descriptive statistics were performed. Results: There were 11 boys and 12 girls. The average age at presentation was 6.8±3.4 years and at the last visit was 13.5±5 years with a mean follow-up of 6.7±3.7 years. Progressive hip subluxation, genu valgum, and ankle valgus were observed in all patients without intervention. Twenty patients had a total of 159 lower extremity surgical procedures (average, 8 procedures per patient). There were 61 hip, 78 knee, and 20 ankle procedures. Surgery resulted in improvement of the center edge angle, femoral head coverage, lateral distal femoral angle, medial proximal tibial angle, tibiofemoral angle, and lateral distal tibial angle. Mechanical axis of the lower extremities improved after intervention. Six patients (12 hips) had recurrence of hip subluxation after acetabular osteotomies and/or femoral varus derotation osteotomy, and 8 patients (16 knees) had postoperative genu valgum recurrence requiring subsequent intervention. There was no recurrent hip subluxation after shelf acetabuloplasty. Conclusions: Progressive hip subluxation, genu valgum, and ankle valgus were seen and often needed surgery. After shelf acetabuloplasty and varus derotation osteotomy, there was no recurrent hip subluxation. Recurrence after genu valgum correction was common. Level of Evidence: Level IV, therapeutic case series.

Upper Cervical Fusion in Children with Morquio Syndrome: Intermediate to Long-term Results

BACKGROUND Paraplegia or death secondary to upper cervical spine instability and spinal cord compression are known consequences of Morquio syndrome. Decompression and fusion of the upper cervical spine are indicated to treat spinal cord compression. The purpose of this study was to report the intermediate to long-term results of upper cervical spine fusion in children with Morquio syndrome. METHODS Twenty patients (nine female and eleven male) with Morquio syndrome who underwent upper cervical spine fusion at a mean age of sixty-three months were retrospectively analyzed with use of hospital records. Radiographic and clinical results were reported. RESULTS The average follow-up period was eight years and ten months. Fusion was achieved in all patients except one; this patient underwent a revision with transarticular C1-C2 screw fixation. Seven patients developed symptomatic instability below the fusion mass that required extension of fusion to lower levels at a mean of ninety-one months after the initial operation. Two patients required decompression and fusion of a site other than the upper cervical spine. Asymptomatic cervicothoracic and thoracolumbar kyphosis was prevalent among our patients. All patients were neurologically stable at the time of the latest follow-up visit. CONCLUSIONS Upper cervical spine fusion provides reliable fusion and a stable neural outcome in patients with Morquio syndrome. However, distal junctional instability is a major problem at long-term follow-up. Kyphotic deformity of the cervicothoracic and thoracolumbar junction may be present in a large number of patients with Morquio syndrome and evaluation for spinal stenosis at these levels should also be considered.

Correction of lower extremity angular deformities in skeletal dysplasia with hemiepiphysiodesis: a preliminary report.

Background: Lower extremity angular deformities are common in children with skeletal dysplasia and can be treated with various surgical options. Both acute correction by osteotomy with internal fixation and gradual correction by external fixation have been used with acceptable results. Recently, the Guided Growth concept using temporary hemiepiphysiodesis for correction of angular deformities in the growing child has been proposed. This study presents the results of temporary hemiepiphysiodesis using eight-Plates and medial malleolus transphyseal screws in children with skeletal dysplasia with lower extremity angular deformities. Methods: Twenty-nine patients (50 lower extremities) with skeletal dysplasia of different types were treated for varus or valgus deformities at 2 centers. The mean age at the time of hemiepiphysiodesis was 10±2.9 years. A total of 66 eight-Plates and 12 medial malleolus screws were used. The average follow-up time between the index surgery and the latest follow-up with the eight-Plate in was 25±13.4 months. Erect long-standing anteroposterior and lateral view radiographs were obtained for deformity planning before the procedure. Angular deformities on radiograph were evaluated by mechanical axis deviation, mechanical lateral distal femoral angle, medial proximal tibial angle, and lateral distal tibial angle. Mechanical axis deviation was also expressed as a percentage to one half of the width of the tibial plateau, and the magnitude of the deformity was classified by determining the zones through which the mechanical axis of the lower extremity passed. Four zones were determined on both the medial and lateral side of the knee and the zones were labeled 1, 2, 3, and 4, corresponding to the severity of the deformity. A positive value was assigned for valgus alignment and a negative for varus alignment. Results: Patients were analyzed in valgus and varus groups. There was correction in 34 of 38 valgus legs and 7 of 12 varus legs. In the valgus group, the mean preoperative and postoperative mechanical lateral distal femoral angles were 82.1±3.7 and 91.1±4.9 degrees, respectively (P<0.001). The mean preoperative and postoperative medial proximal tibial angles were 98.5±8 and 87.8±7.1 degrees, respectively (P<0.001). Six patients with bilateral ankle valgus deformities (12 ankles) underwent single-screw medial malleolus hemiepiphysiodesis. The mean preoperative and postoperative lateral distal tibial angles were 73.9±8.7 and 86.1±6.8 degrees, respectively (P<0.001). The numbers of plates in each anatomic location were not enough to make statistical conclusions in varus legs. Four patients in the valgus group and 3 patients in the varus group did not benefit from the procedure. Mechanical axes were in zone 2 or over in 94% of the legs preoperatively, whereas postoperatively, only 23% of the legs had mechanical axes in zone 2 or over in varus and valgus groups. Conclusions: Growth modulation with an eight-Plate is a relatively simple surgery and has low risk of mechanical failure or physeal damage. It can be performed in very young patients, which is an important advantage in skeletal dysplasia. Screw purchase is reliable even in the abnormal epiphysis and metaphysis. Our results show that Guided Growth using eight-Plates in skeletal dysplasia is safe and effective. Level of Evidence: Level IV.

Differences in early sagittal plane alignment between thoracic and lumbar adolescent idiopathic scoliosis

BACKGROUND CONTEXT It has previously been shown that rotational stability of spinal segments is reduced by posteriorly directed shear loads that are the result of gravity and muscle tone. Posterior shear loads act on those segments of the spine that are posteriorly inclined, as determined by each individuals inherited sagittal spinal profile. Accordingly, it can be inferred that certain sagittal spinal profiles are more prone to develop a rotational deformity that may lead to idiopathic scoliosis; and lumbar scoliosis, on one end of the spectrum, develops from a different sagittal spinal profile than thoracic scoliosis on the other end. PURPOSE To examine the role of sagittal spinopelvic alignment in the etiopathogenesis of different types of idiopathic scoliosis. STUDY DESIGN/SETTING Multicenter retrospective analysis of lateral radiographs of patients with small thoracic and lumbar adolescent idiopathic scoliotic curves. PATIENTS SAMPLE We included 192 adolescent idiopathic scoliosis patients with either a thoracic (n=128) or lumbar (n=64) structural curve with a Cobb angle of less than 20° were studied. Children with other spinal pathology or with more severe idiopathic scoliosis were excluded, because this disturbs their original sagittal profile. Subjects who underwent scoliosis screening and had a normal spine were included in the control cohort (n=95). OUTCOME MEASURES Thoracic kyphosis, lumbar lordosis, T9 sagittal offset, C7 and T4 sagittal plumb lines, pelvic incidence, pelvic tilt, and sacral slope, as well as parameters describing orientation in space of each individual vertebra between C7 and L5 and length of the posteriorly inclined segment. METHODS On standardized lateral radiographs of the spine, a systematic, semi-automatic measurement of the different sagittal spinopelvic parameters was performed for each subject using in-house developed computer software. RESULTS Early thoracic scoliosis showed a significantly different sagittal plane from lumbar scoliosis. Furthermore, both scoliotic curve patterns were different from controls, but in a different sense. Thoracic kyphosis was significantly decreased in thoracic scoliosis compared with both lumbar scoliosis patients and controls. For thoracic scoliosis, a significantly longer posteriorly inclined segment, and steeper posterior inclination of C7-T8 was observed compared with both lumbar scoliosis and controls. In lumbar scoliosis, the posteriorly inclined segment was shorter and located lower in the spine, and T12-L4 was more posteriorly inclined than in the thoracic group. The lumbar scoliosis cohort had a posteriorly inclined segment of the same length as controls, but T12-L2 showed steeper posterior inclination. Lumbar lordosis, pelvic incidence, pelvic tilt, and sacral slope, however, were similar for the two scoliotic subgroups as well as the controls. CONCLUSIONS This study demonstrates that even at an early stage in the condition, the sagittal profile of thoracic adolescent idiopathic scoliosis differs significantly from lumbar scoliosis, and both types of scoliosis differ from controls, but in different aspects. This supports the theory that differences in underlying sagittal profile play a role in the development of different types of idiopathic scoliosis.

Anterior Distal Femoral Stapling for Correcting Knee Flexion Contracture in Children With Arthrogryposis—Preliminary Results

Background Fixed flexion contractures of the knee are more common and disabling than extension contractures in children with arthrogryposis. For correcting these deformities, there are various surgical options such as soft tissue release, distal femoral osteotomy, and frame distraction. We sought in this study to examine the effectiveness of anterior distal femoral stapling using 8-plates for correcting knee flexion contracture in children with arthrogryposis. Methods We retrospectively assessed 16 knees in 10 children using clinical and radiographic measures. To determine the outcome, we assessed the Functional Mobility Scale (FMS) as well. Statistically, a paired t test, independent t test, and Wilcoxon signed-rank test were used to analyze the results. Results After anterior distal femoral stapling, there was a reduction in the flexion deformity of the knee in children with arthrogryposis, P<0.05. There was an estimated 18-degree correction comparing the mean preoperative flexion deformity and the mean postoperative flexion deformity. This correction was significant in children when the knee flexion deformity was less than 45 degrees. The FMS also improved in those patients where the residual flexion contracture was less than 30 degrees at follow-up, suggesting an improvement in their ambulatory capacity, P<0.05. Conclusion Among children with arthrogryposis who present with knee flexion contractures, anterior distal femoral stapling with 8-plates improved their flexion deformity and ambulatory capacity. This technique is less invasive than soft tissue releases, distal femoral osteotomy, or frame distraction and is most rewarding in children with arthrogryposis whose flexion contractures is less than 45 degrees.

Electronic monitoring of scoliosis brace wear compliance.

PurposeAccurate evaluation of patient compliance with scoliosis brace usage has been a challenge for physicians treating patients with adolescent idiopathic scoliosis. This inability to accurately measure compliance has resulted in difficulty in determining brace treatment efficacy. This prospective study was performed to demonstrate the efficacy of using a new electronic brace compliance monitor, the Cricket.MethodsThe Cricket is a small encased circuit that can be attached to the brace and, by means of a temperature sensor, can record brace wear times. This study included ten subjects with adolescent idiopathic scoliosis who were prescribed the Wilmington scoliosis brace (thoraco-lumbo-sacral orthosis) into which the Cricket sensor was incorporated. Subjects kept a diary of brace wear times.ResultsComparisons of data for the Cricket, subject diaries, and prescribed brace wear were evaluated. The mean error between the diary times and Cricket recording was 2%. Patient compliance was 78%.ConclusionsThe Cricket is a reliable, accurate, and sensitive device to determine patient compliance with scoliosis brace usage.

Prediction of Curve Progression in Idiopathic Scoliosis: Validation of the Sanders Skeletal Maturity Staging System.

Study Design. Retrospective case series. Objective. This study aimed to validate the Sanders Skeletal Maturity Staging System and to assess its correlation to curve progression in idiopathic scoliosis. Summary of Background Data. The Sanders Skeletal Maturity Staging System has been used to predict curve progression in idiopathic scoliosis. This study intended to validate that initial study with a larger sample size. Methods. We retrospectively reviewed 1100 consecutive patients with idiopathic scoliosis between 2005 and 2011. Girls aged 8 to 14 years (<2 yr postmenarche) and boys aged 10 to 16 years who had obtained at least 1 hand and spine radiograph on the same day for evaluation of skeletal age and scoliosis curve magnitude were followed to skeletal maturity (Risser stage 5 or fully capped Risser stage 4), curve progression to 50° or greater, or spinal fusion. Patients with nonidiopathic curves were excluded. Results. There were 161 patients: 131 girls (12.3 ± 1.2 yr) and 30 boys (13.9 ± 1.1 yr). The distribution of patients within Sanders stage (SS) 1 through 7 was 7, 28, 41, 45, 7, 31, and 2 patients, respectively; modified Lenke curve types 1 to 6 were 26, 12, 63, 5, 38, and 17 patients, respectively. All patients in SS2 with initial Cobb angles of 25° or greater progressed, and patients in SS1 and SS3 with initial Cobb angles of 35° or greater progressed. Similarly, all patients with initial Cobb angles of 40° or greater progressed except those in SS7. Conversely, none of the patients with initial Cobb angles of 15° or less or those in SS5, SS6, and SS7 with initial Cobb angles of 30° or less progressed. Predictive progression of 67%, 50%, 43%, 27%, and 60% was observed for subgroups SS1/30°, SS2/20°, SS3/30°, SS4/30°, and SS6/35° respectively. Conclusion. This larger cohort shows a strong predictive correlation between SS and initial Cobb angle for probability of curve progression in idiopathic scoliosis. Level of Evidence: 3

Flexion-extension cervical spine MRI in children with skeletal dysplasia: is it safe and effective?

Background: Skeletal dysplasias may be associated with cervical spinal instability or stenosis. Cervical spine flexion-extension plain radiographs in children with skeletal dysplasia are difficult to interpret. The purpose of this study was to review the indications, efficacy, and safety of performing flexion-extension magnetic resonance imaging (MRI) under sedation/anesthesia in these children. Methods: Retrospective, Institutional Review Board–approved review of 31 children with skeletal dysplasia who underwent 38 cervical spine flexion-extension MRI studies under sedation/anesthesia. Indications included abnormal neurological examination, suspected instability, stenosis, or inconclusive findings on flexion-extension radiographs. Studies were performed by the radiology technologist as directed by the radiologist with an anesthesiologist present. MRI was evaluated for odontoid hypoplasia, os odontoideum, cerebrospinal fluid effacement, cord compression, spinal cord changes, cervical canal narrowing in the neutral, flexion, and extension positions. Neurological examinations were recorded before and after MRI to assess safety. Results: The average age at MRI was 3 years, 2 months. In 6 patients whose plain radiographs showed C1-C2 or subaxial instability, flexion-extension MRI showed no cord compression. Nine patients with inconclusive plain radiographs had abnormal MRI findings. An os odontoideum not seen on plain radiographs was diagnosed in 3 patients on flexion-extension MRI. On the basis of the MRI findings, 14 patients underwent surgery, 9/14 had increased cord compression in flexion or extension compared with neutral, and observation was continued in 17 others. Patients who underwent surgery had significant cord compression on MRI. There were no significant changes in the neurological examinations after MRI. Conclusions: Cervical spine flexion-extension MRI under sedation/anesthesia in children with skeletal dysplasia is safe under adequate supervision and is necessary to guide accurate medical and surgical decision making. Flexion-extension MRI is useful for identifying dynamic changes in canal diameter resulting in cord compression not seen on plain radiographs, and it is also useful for identifying patients with suspected plain film instability who may not have stenosis or cord compression on MRI. Study Design: Level IV—retrospective case series.