Comparative analysis of hook, hybrid, and pedicle screw instrumentation in the posterior treatment of adolescent idiopathic scoliosis.

BACKGROUND: Spinal instrumentation in adolescent idiopathic scoliosis (AIS) aims to correct spinal deformity and maintain long-term spinal stability until bony healing is ensured. The purpose of this study was to compare the minimum 2-year postoperative radiographic and clinical results of posterior spine correction and fusion with all-hook instrumentation versus hybrid segmental instrumentation versus pedicle screw instrumentation for AIS from a single institution. METHODS: A total of 105 patients with AIS who underwent a posterior spinal fusion with segmental pedicle screw (35), hook (35), or hybrid (35) instrumentation were sorted and matched according to the following criteria: similar age at surgery, identical Lenke curve types, curve magnitude, and Risser grade. Patients were evaluated before, immediately after, and at 2 years after surgery for radiographic parameters, complications, and outcome, as well as on the basis of the Scoliosis Research Society (SRS) questionnaire. RESULTS: The age and Risser grade, major curve Cobb angle, apical vertebral rotation (AVR), apical vertebral translation (AVT), lowest instrumented vertebral tilt, global coronal and sagittal balance, lumbar lordosis, and thoracic kyphosis were determined as part of preoperative evaluation. All 3 groups showed significant differences between the preoperative and postoperative major curve Cobb angle, lowest instrumented vertebral tilt, AVT, and AVR. At the latest follow-up, lumbar lordosis, thoracic kyphosis, and global coronal and sagittal balance remained similar among the 3 groups. Major curve Cobb angle, AVT, and AVR were significantly different--the hook group's measurements were significantly higher than the other groups, but there was no difference between the pedicle screw and hybrid groups. Major curve correction rate was significantly different among all groups (screw=71.9%±13.8%, hybrid=61.4%±16.6%, hook=48.1%±19.7%) (P<0.001). The pedicle screw group had the least amount of correction loss but there was no statistically significant difference between groups (screw=2.6±6.7 degrees, hybrid=4.5±7.4 degrees, hook=4.4±6.2 degrees) (P=0.35). The hook group had the least amount of AVT correction, but the screw group and the hybrid groups were similar (pedicle=67.3%±15.5%, hybrid=57.5%±22.4%, hook=39.9%±32.5%) (P<0.001). Surgery time and blood loss were higher in the screw group. No differences in global SRS-22 scores were demonstrated between the patients treated with pedicle screw, hybrid, and hook constructs; however, the satisfaction domain was higher in the screw group at the latest follow-up. CONCLUSIONS: Pedicle screw and hybrid instrumentations offer significantly better spinal deformity correction than hook constructs in major curve coronal correction, AVT, and AVR. Patients with pedicle screw instrumentation had the greatest curve correction percentage, maintenance of this correction in the coronal and sagittal planes, and higher patient satisfaction by the SRS outcome scores. Global SRS-22 scores were similar at 2-year follow-up in all groups. LEVEL OF EVIDENCE: Therapeutic level III retrospective comparative study.

Little league shoulder: case report and literature review.

When compared with adults, children have unique injury patterns secondary to their anatomical differences. The susceptibility of the growth plate to injury is well-documented. "Little Leaguer's shoulder" is the term used for injury to the open proximal humeral epiphysis in the Little League pitcher. We present a case report and literary review. Discussed are the possible etiologies, patient presentation, physical exam, radiographic findings, and treatment recommendations.

Distal humeral epiphyseal separation.

Distal humeral epiphyseal separation is an uncommon injury that is often misdiagnosed upon initial presentation. To make a timely, correct diagnosis, the treating physician must have a thorough understanding of basic anatomical relationships and an awareness of the existence of this injury. This is a case of a child who sustained a separation of the distal humeral epiphysis, as well as multiple other bony injuries, secondary to child abuse.

Spondyloepimetaphyseal dysplasia with joint laxity (SEMDJL).

Spondyloepimetaphyseal dysplasia with joint laxity (SEMDJL) is a distinctive form of skeletal dysplasia characterized by severe dwarfism, generalized articular hypermobility, and progressive spinal malalignment. We report on a patient with SEMDJL, who presented with all the characteristic orthopedic manifestations of the disorder, required multiple operative procedures, and has the longest reported follow-up and survival into adulthood with a favorable outcome. We describe all the clinical and radiographic findings that can allow an early diagnosis of this type of skeletal dysplasia, which can lead to profound disability with potentially lethal spinal and pulmonary complications in early childhood. In view of the severe clinical and genetic implications, diagnostic precision is of vital importance, particularly since the disorder is currently believed to be more common than initially reported.

Factors influencing the development of osteonecrosis in patients treated for slipped capital femoral epiphysis.

BACKGROUND: Osteonecrosis is a serious complication of the treatment of slipped capital femoral epiphysis. The purpose of the present study was to identify factors influencing the development of osteonecrosis. METHODS: Two hundred and forty patients who had been treated for slipped capital femoral epiphysis between 1965 and 1999 were retrospectively evaluated. Treatment included stabilization with a spica cast or fixation with one to four pins or screws. Radiographs that had been made at the time of presentation, before and after the operation, and at consecutive follow-up examinations were reviewed. Osteonecrosis was defined retrospectively on the basis of radiographic evidence of sclerosis and collapse of the femoral head. The risk of development of osteonecrosis was correlated with various clinical and radiographic parameters. RESULTS: All twenty-one patients in whom osteonecrosis developed had presented with an unstable slipped capital femoral epiphysis. None of the 204 patients who had presented with a stable slipped capital femoral epiphysis, regardless of grade, had development of osteonecrosis. In the group of patients who had presented with an unstable slipped capital femoral epiphysis, the risk of development of osteonecrosis increased with the severity (grade) of the slip. Osteonecrosis was more likely to develop in patients who had been treated with multiple pins than in those who had been treated with a single cannulated screw. CONCLUSIONS: Patients who have a stable slipped capital femoral epiphysis are not at risk for the development of osteonecrosis when treated with pinning in situ. Patients who have an unstable slipped capital femoral epiphysis have a decreased risk of osteonecrosis when treated with pinning in situ. Complete or partial reduction of an unstable slipped capital femoral epiphysis increases the risk of development of osteonecrosis. Pinning in situ without reduction with a single cannulated screw is the method of choice for the treatment of a slipped capital femoral epiphysis.

Spinal deformity in chondrodysplasia punctata.

BACKGROUND DATA: Our purpose was to describe the deformities, natural history, and course of treatment in chondrodysplasia punctata, a skeletal dysplasia characterized by stippled epiphysis in infancy, short stature, and progressive kyphoscoliosis. STUDY DESIGN: We identified 20 patients (15 female, 5 male) with chondrodysplasia punctata and spinal abnormalities. RESULTS: The spinal deformity was rarely present in the neonatal radiographs but typically appeared during the first year. We identified three patterns of spinal deformity. The first was a C2 dentocentral synchondrosis separation, which was successfully fused. Scoliosis had two patterns: one slowly progressive without dysplastic vertebrae or significant kyphosis (two patients) and the other rapidly progressive with dysplastic vertebral bodies often appearing similar to a congenital kyphoscoliosis (17 patients). Follow-up averaged 7.9 years (range 2-20 years). The slowly progressive type was fused successfully with standard posterior techniques. The dysplastic type, however, required on average 2.5 procedures, including anteroposterior fusions, repeat fusions for pseudarthrosis repair, extension of the fusions for progression beyond the curves, and osteotomies for progression through the fusion mass. Unlike congenital deformities, they did not respond well to hemiepiphysiodesis. CONCLUSION: Three types of spinal deformities were identified in children with chondrodysplasia punctata, including cervical bony disruption, a slowly progressive, nondysplastic scoliosis responding well to standard fusion techniques and a dysplastic kyphoscoliosis, which is rapidly progressive and resistant to fusion. The best results in dysplastic curves are obtained with an anterior strut graft and a posterior fusion. The patients must be observed long-term for further vertebral dysplasia and progressive kyphoscoliosis.