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Biomedical subjects

John P Dormans

Publications and source records attributed to John P Dormans.

At least 19 recordsLinked to original sources
PubMed2007

Comparison of Cobb angle measurement of scoliosis radiographs with preselected end vertebrae: traditional versus digital acquisition.

STUDY DESIGN: Prospective study. OBJECTIVE: To compare variability in Cobb angle between digitally and traditionally acquired scoliosis radiographs. SUMMARY OF BACKGROUND DATA: Previous studies have shown that the 95% confidence interval for Cobb angle can vary from 2.6 degrees to 8.8 degrees. No study directly comparing Cobb angles measured from traditional and digitally acquired radiographs has been reported. METHODS: A spine model simulating 25 single right thoracic curves (range, 20 degrees-60 degrees) was imaged using traditional and digital techniques. Traditional films and miniaturized printed digital films were each measured twice manually. Digital films were also measured twice using computer imaging software. RESULTS: Overall mean angle and (95% confidence interval) were 41.7 degrees (39.1 degrees-44.3 degrees) for traditional, 40.6 degrees (37.4 degrees-43.8 degrees) for digital, and 39.7 degrees (36.3 degrees-43.1 degrees) for computer measurements. Overall correlation was 0.994 for traditional and digital, 0.987 for traditional and computer, and 0.993 for digital and computer. Fixed effect model analysis demonstrated that, although a statistically significant difference existed between the 3 methods of measuring the Cobb angle (P < 0.0001), the difference between methods was less than 2 degrees. CONCLUSIONS: Any of the 3 evaluated methods of measurement can be used to measure Cobb angles. Additionally, the methods can be used interchangeably.

Image Interpretation, Computer-Assisted↗
PubMed2007

Acetabular dysplasia with hip subluxation in Trevor's disease of the hip.

Dysplasia epiphysealis hemimelica (Trevor's disease) is a rare developmental bone disorder characterized by single or multiple epiphyseal intraarticular lesions that are usually unilateral and restricted to one side of the limb. Although the process often is limited to the lower extremity, hip involvement is not common. When it occurs it is more commonly limited to the femoral side. We report a 14-year-old boy with Trevor's disease involving the hip, femoral and acetabular sides, and with progressive dysplasia. We describe a new surgical approach to this rare condition using a two-stage procedure consisting of intraarticular resection of the lesion followed by a modified shelf acetabuloplasty in a second stage to prevent compromise of the proximal femur vasculature, and to allow preservation and improvement of range of motion of the hip. At 36 months followup the patient is pain-free, has full range of motion, improved gait, and no signs of recurrence. Although technically challenging, the two-stage approach to Trevor's disease seems a reasonable and safe method.

Acetabulum↗
PubMed2007

Pediatric primary bone lymphoma-diffuse large B-cell lymphoma: morphologic and immunohistochemical characteristics of 10 cases.

Most primary bone lymphomas (PBLs) are diffuse large B-cell lymphomas (DLBCLs). Pediatric PBL-DLBCL has a favorable prognosis but remains poorly characterized. Herein, 10 such cases are detailed. They involved 11- to 20-year-old males with bone lesions that were often painful. They were diagnosed often after months to years of symptoms, suggesting an indolent disease. All were successfully treated with chemotherapy with or without radiotherapy (0.5- to 24-year followup). Biopsy revealed that the lymphomas were paratrabecular or diffuse and were medium- to large-sized with round to irregular nuclei, dispersed chromatin, indistinct to small nucleoli, and abundant cytoplasm. Other features included varying levels of necrosis, cytoplasmic retraction, and myeloid hyperplasia. All cases marked as mature B cells, and most were CD10+ (7/10). Typical centroblastic morphologic features with nucleoli were rare, multilobated nuclei were uncommon, and CD10 negativity did not predict poor prognosis, unlike in the adult PBL-DLBCL. These findings suggest that pediatric and adult PBL-DLBCLs are distinct entities.

Adolescent↗
PubMed2006

Change in lordosis at the occipitocervical junction following posterior occipitocervical fusion in skeletally immature children.

STUDY DESIGN: Retrospective case series. OBJECTIVE: Evaluate the change in lordosis at the occipitocervical junction occurring during growth in skeletally immature children treated with posterior occipitocervical arthrodesis versus patients skeletally mature at arthrodesis. SUMMARY OF BACKGROUND DATA: Posterior occipitocervical arthrodesis is often indicated for children who have instability of the upper cervical spine develop. Theoretically, in skeletally immature children, this approach retards the growth of the posterior spinal elements but allows the anterior spinal column to continue to grow with the risk of excessive lordosis of the cervical spine developing. METHODS: There were 21 children, younger than 11 years (range 1.9-10.9) at surgery and expected to have normal spinal growth, followed radiographically for an average of 6.3 years (range 2.0-12.4). Postoperative lateral neutral radiographs were compared to those at most recent follow-up to measure the change in occipitocervical angle. These results were then compared to a series of control patients who were skeletally mature at surgery. RESULTS: Average overall change in lordosis at the occipitocervical junction was -4.6 degrees (range -12.8 degrees to +6.5 degrees). Average annualized change was -0.28 degrees per vertebral level per year (range -1.13 degrees to +0.67 degrees). This annualized change in angle was statistically significant compared to the average change of +0.01 degrees (range -0.09 degrees to +0.11 degrees) measured in the control series of patients skeletally mature at surgery (P = 0.01). CONCLUSIONS: Increasing lordosis occurs at the occipitocervical junction following fusion in skeletally immature children. If occipitocervical arthrodesis is indicated in a skeletally immature child, fusion in excessive extension and overtightening of posterior wires should be avoided.

Atlanto-Occipital Joint↗
PubMed2006

Os odontoideum revisited: the case for a multifactorial etiology.

STUDY DESIGN: Retrospective analysis of our experience with os odontoideum at the Children's Hospital of Philadelphia. OBJECTIVE: To review the origin of os odontoideum and provide evidence for two separate etiologies. SUMMARY OF BACKGROUND DATA: The etiology of os odontoideum has been debated in the literature. Most authors support a post-traumatic etiology; however, some evidence exists to support a congenital origin. METHODS: We reviewed all 519 abnormal cervical spine radiographs performed from 1991 to 2004 to identify os odontoideum. Medical records and imaging studies were examined to determine: history of trauma, severity of injury, interval from injury to presentation, coexisting syndromes, and associated congenital cervical spine anomalies. RESULTS: Sixteen of 519 patients (3.1%) had os odontoideum. Only 8 of 16 patients reported previous trauma. Only 3 of these 8 injuries occurred with an interval remote enough to allow remodeling of the dens to an ossicle by the time of presentation. Six of 16 patients had associated congenital anomalies in the cervical spine. Three of 16 had a coexisting genetic syndrome. CONCLUSION: Our data supports two separate etiologies for the os odontoideum: post-traumatic and congenital. The data should raise awareness that some children with preexisting syndromes may develop os odontoideum without previous trauma.

Adolescent↗
PubMed2006

Langerhans cell histiocytosis and human herpes virus 6 (HHV-6), an analysis by real-time polymerase chain reaction.

Patients with Langerhans cell histiocytosis (LCH) usually present to orthopedic surgeons because this disease most commonly affects bone. The pathogenesis of LCH is unknown, although roles for environmental, infectious, immunologic, and genetic causes have been postulated. More specifically, there is limited data suggesting that human herpes virus 6 (HHV-6) may be a potential etiologic agent. Frozen biopsy material was obtained from 13 patients with LCH and 20 patients without the disease. After ensuring histologic adequacy of the material, the tissue was tested for HHV-6 by qualitative and quantitative real-time TaqMan PCR. Four of 13 patients with LCH had evidence of HHV-6 DNA in their tissue while 7 of 20 control patients tested positive for HHV-6 genome. Viral loads are reported for the positive patients; no statistical difference was observed in the presence or quantity of HHV-6 DNA found in either population, suggesting that the prevalence of HHV-6 in the tissue of LCH patients is the same as that found in tissue from individuals without disease.

Adolescent↗
PubMed2006

Primary non-Hodgkin's lymphoma of bone in children.

BACKGROUND: Primary non-Hodgkin's lymphoma of bone, often more simply referred to as primary lymphoma of bone, is a rare subset of non-Hodgkin's lymphoma in children. There are only a few small series of primary lymphoma of bone in children with long-term follow-up, and none have appeared in the orthopaedic literature. METHODS: A review of our institution's Pediatric Tumor Registry identified fifteen cases of primary lymphoma of bone among 306 cases of diagnosed non-Hodgkin's lymphoma between 1970 and 2003. Retrospective evaluation included collection of demographic, clinical, radiographic, treatment, and follow-up data. A univariate analysis was used to assess the prognostic significance of risk factors with respect to survival of patients from this series and in a summary analysis of data collected from similar series in the literature. RESULTS: The patients included ten male and five female patients with a mean age of 11.6 years. Most patients had a presenting complaint of pain and had swelling and/or tenderness on physical examination. Eight children had a solitary bone lesion, and seven had multiple bone lesions. Overall, the mean number of bones involved was 3.1 per patient. The femur and the pelvis were the most frequently involved bones. The ten surviving patients were followed for a mean of 13.6 years. Five patients died: three of disease progression, one of treatment-related complications, and one of an unrelated cause. The mean time from diagnosis to death was 2.1 years. Nine patients received chemotherapy only, whereas six patients received a combination of chemotherapy and radiation therapy. In the present study, an age of nine years or less was predictive of poor survival (p < 0.05). In the summary analysis of cases collected from the literature, advanced stage, young age, non-large-cell histology, and multiple-bone involvement were predictive of poor survival (p < 0.05). CONCLUSIONS: On the basis of the present series and a comprehensive review of similar series in the literature involving patients with primary lymphoma of bone, it appears that younger age, advanced-stage disease, multiple-bone involvement, and non-large-cell histology are associated with decreased survival as compared with older age, localized disease, single-bone involvement, and large-cell histology, respectively.

Adolescent↗
PubMed2006

Factors distinguishing septic arthritis from transient synovitis of the hip in children. A prospective study.

BACKGROUND: Distinguishing septic arthritis from transient synovitis of the hip in children can be challenging. Authors of recent retrospective studies have used presenting factors to establish algorithms for predicting septic arthritis of the hip in children. This study differs from previous work in three ways: data were collected prospectively, C-reactive protein levels were recorded, and the focus was on children in whom the findings were so suspicious for septic arthritis that hip aspiration was performed. METHODS: Over four years, we prospectively collected data on every child (a total of fifty-three) who underwent hip aspiration because of a suspicion of septic arthritis at our institution. Diagnoses of confirmed septic arthritis, presumed septic arthritis, and transient synovitis were determined on the basis of the results of Gram staining, culture, and a cell count of the hip aspirate. Presenting factors and laboratory values were recorded. To evaluate the strength of predictors, we performed univariate and multivariate analysis on data from forty-eight patients who met the inclusion criteria. RESULTS: Univariate analysis showed that fever, the C-reactive protein level, and the erythrocyte sedimentation rate were strongly associated with the final diagnosis (p < 0.05). On multivariate analysis, the C-reactive protein level and erythrocyte sedimentation rate were found to be significant predictors. However, the erythrocyte sedimentation rate was not independent of the C-reactive protein level on backward elimination, and the C-reactive protein level was the only risk factor that was strongly associated with the outcome at a 5% significance level. Patients with five predictive factors had a 98% chance of having septic arthritis, those with four factors had a 93% chance, and those with three factors had an 83% chance. CONCLUSIONS: This prospective study of children who presented with findings that were highly suspicious for septic arthritis of the hip builds on the work of previous authors. We found fever (an oral temperature >38.5 degrees C) was the best predictor of septic arthritis followed by an elevated C-reactive protein level, an elevated erythrocyte sedimentation rate, refusal to bear weight, and an elevated serum white blood-cell count. In our study group, a C-reactive protein level of >2.0 mg/dL (>20 mg/L) was a strong independent risk factor and a valuable tool for assessing and diagnosing children suspected of having septic arthritis of the hip.

Adolescent↗
PubMed2006

Nontraumatic upper cervical spine instability in children.

The upper cervical spine begins at the base of the occiput, continues caudally to the C2-C3 disk space, and includes the occipitoatlantal and atlantoaxial joints. Nontraumatic upper cervical spine instability can result from abnormal development of osseous or ligamentous structures or from gradually increasing ligamentous laxity associated with connective tissue disorders. Such instability can lead to compression of the spinal cord during movement of the cervical spine. Establishing a correct diagnosis includes performing a thorough physical examination as well as evaluating radiographic relationships and measurements. Appropriate management of syndromes associated with instability of the upper cervical spine includes preventive care and recommendations for sports participation. Surgical treatment for the upper cervical spine includes a posterior surgical approach, used for instability, and the use of rigid plate implants, wiring, and bone graft materials to achieve a solid spinal fusion.

Age Factors↗
PubMed2006

Down syndrome in children: the role of the orthopaedic surgeon.

Down syndrome, the result of trisomy of chromosome 21, is one of the most common chromosomal abnormalities. Patients have a characteristic facial appearance, variable levels of intelligence and self-care skills, and a variety of associated medical conditions. Orthopaedic manifestations occur frequently; most are related to hypotonia, joint hypermobility, and ligamentous laxity. Atlanto-occipital and atlantoaxial hypermobility, as well as bony anomalies of the cervical spine, can produce atlanto-occipital and cervical instability. Methods of screening for this instability, particularly with regard to participation in sports, are a subject of controversy. Scoliosis, hip instability, slipped capital femoral epiphysis, patellar instability, and foot deformities are other musculoskeletal conditions found in patients with Down syndrome that can be challenging for the orthopaedic surgeon to treat.

Adolescent↗
PubMed2005

Scoliosis correction in an adolescent with a rigid spine syndrome: case report.

STUDY DESIGN: Details of presentation and approach to the treatment of scoliosis in a case of a Rigid Spine Syndrome (RSS). OBJECTIVE: To report on the results of conservative and operative treatment of scoliosis associated with RSS, and, based on this, to propose an assessment and treatment protocol for this condition. SUMMARY OF BACKGROUND DATA: Congenital muscular dystrophies (CMD) are a group of disorders marked by hypotonia at birth and a generally nonprogressive course of muscle weakness. Spinal rigidity is present in a number of patients with CMD. RSS is classified as a CMD, and is characterized by early rigidity of the spine, limb contractures, and restrictive respiratory dysfunction. An approach to the treatment of scoliosis in RSS has not been established. METHODS: Details of history, diagnostic tests, and treatment of an adolescent with RSS associated with progressive scoliosis and cervical spine extension contracture is presented. The role of brace treatment, Botox (Allergan, Inc., Irvine, CA), and details of operative correction, including histology of back muscles, is defined. RESULTS: In this case of RSS with rigid scoliosis nonresponsive to brace therapy and Botox injections, an anterior thoracolumbar spine fusion with instrumentation was successfully performed for correction of the scoliosis, and the cervical spine was addressed through a posterior approach and an occiput-cervical fusion. We outline the details of surgical procedure and restoration of spinal balance in both sagittal and coronal planes. CONCLUSIONS: The chromosomal bases of CMD and characteristic features of RSS, including diagnostic tests, have been reviewed. Surgical intervention with spinal deformity fusion, correction, and instrumentation is indicated in RSS with progressive spinal imbalance not responding to conservative therapy is safe and can give promising results.

Adolescent↗
PubMed2005

Developmental anomalies of the cervical spine in patients with fibrodysplasia ossificans progressiva are distinctly different from those in patients with Klippel-Feil syndrome: clues from the BMP signaling pathway.

STUDY DESIGN: A radiographic analysis of the cervical spine of 70 patients diagnosed with fibrodysplasia ossificans progressiva (FOP) and 33 diagnosed with Klippel-Feil (KF) syndrome was conducted. OBJECTIVES: The objectives of this study were to describe cervical spine abnormalities in patients with FOP, to compare and contrast those findings with the malformations in patients with KF syndrome, and to examine the possible etiology of these abnormalities. SUMMARY OF BACKGROUND DATA: Congenital features of diseases often provide seminal clues to underlying etiology and developmental pathways. While progressive metamorphosis of connective tissue to heterotopic bone is the most dramatic and disabling feature of FOP, less severe congenital anomalies of the skeleton are also present. Vertebral fusions observed in KF are consistent with defects in embryonic segmentation. METHODS: The cervical spine plain films of 70 FOP patients and 33 KF patients with documented congenital abnormalities were reviewed. RESULTS: Generalized neck stiffness and decreased range of motion were noted in most children with FOP. In the FOP patient group, characteristic anomalies, including large posterior elements, tall narrow vertebral bodies,and fusion of the facet joints between C2 and C7, were observed. Most notably, these characteristic anomalies of the cervical spine in patients with FOP were distinctly different from those of 33 patients with KF that were examined but were strikingly similar to those seen in mice with homozygous deletions of the gene-encoding noggin, a bone morphogenetic protein (BMP) antagonist. CONCLUSIONS: FOP patients exhibit a characteristic set of congenital spine malformations. While the noggin gene (NOG) is not mutated in patients who have FOP, these findings extend a growing body of evidence implicating overactivity of the BMP signaling pathway in the molecular pathogenesis of FOP.

Adolescent↗
PubMed2005

Molecular analysis of congenital scoliosis: a candidate gene approach.

The etiology of congenital scoliosis is largely unknown. The severe vertebral disorder, spondylocostal dysostosis type 1, is associated with a homozygous delta-like 3 (DLL3) mutation. Scoliosis has been observed in a heterozygous DLL3 carrier, raising the possibility of its involvement in congenital scoliosis. We present the first molecular study of congenital scoliosis by analysis of the candidate gene DLL3 and demonstrate one novel missense variant. However, no novel or previously described mutations are present in our cohort, indicating that DLL3 mutations may not be a major cause of congenital scoliosis. Additionally, we have evaluated patients with congenital scoliosis not diagnosed with a known syndrome and identified a significant number of associated renal and cardiac anomalies and familial incidence of idiopathic scoliosis in this group.

Abnormalities, Multiple↗
PubMed2005

The diagnostic accuracy of MRI versus CT imaging for osteoid osteoma in children.

UNLABELLED: Advanced imaging often is obtained in children suspected of having osteoid osteoma. We hypothesized that magnetic resonance imaging gives a falsely aggressive appearance and that computed tomography is better for identifying osteoid osteoma. This is the first prospective blinded study comparatively assessing these imaging studies in children. Twelve preoperative magnetic resonance imaging scans of confirmed cases of osteoid osteoma were collected. Three radiologists blinded to the diagnosis reviewed these images. Only a clinical history of skeletal pain was given. Lesions were classified as benign-latent, benign-aggressive, or malignant. Radiologists were asked to list their primary diagnosis (with a confidence level from 1-10). Seven of these 12 children also had computed tomography scans that subsequently were reviewed in similar manner. With computed tomography scans, lesions were accurately identified as benign-latent (15/21 readings, 71%) and as osteoid osteoma (14/21 readings) more frequently than with magnetic resonance imaging scans (7/36 readings, 19%). LEVEL OF EVIDENCE: Diagnostic study, Level III-1 (study of nonconsecutive patients--no consistently applied reference gold standard). See the Guidelines for Authors for a complete description of levels of evidence.

Adolescent↗
PubMed2005

Case report: Reconstruction of an intercalary defect with bone transport after resection of Ewing's sarcoma.

We report a 13-year-old girl with Ewing's sarcoma of the tibia who was treated with multiagent chemotherapy, followed by local control tumor surgery consisting of wide resection of the tumor and bone transport with distraction osteogenesis for reconstruction. The bone defect created by resection was 13 cm long and was replaced by bone transport using a monolateral external fixator. Evaluation of the resected specimen revealed wide tumor-free margins with 100% chemonecrosis. A planned Harmon-type autogenous bone grafting between the middle and proximal segments of the tibia (docking site) was done primarily after docking occurred, and a solid union was obtained by 23 months after resection. The bone healing index (treatment index) was 54 days/1 cm distraction, which is indicative of slow healing. Clinical evaluation of the affected extremity using the Musculoskeletal Tumor Society rating system revealed 80% normal functional capability. Indications for bone transport in reconstruction of bone defects created by wide resection of bone sarcomas are discussed. In retrospect, we have concerns regarding the suitability of this technique in the setting of diaphyseal sarcoma reconstruction in patients with Ewing's sarcoma who require aggressive and intense multiagent chemotherapy.

Adolescent↗
PubMed2005

Traumatic atlanto-occipital dislocation in children.

BACKGROUND: Traumatic atlanto-occipital dislocation in children and adolescents is a rare and often fatal injury. Although historically most reported cases have been fatal, the advent of modern prehospital care has led to an increase in survival following this injury. As a consequence, some patients may achieve or maintain satisfactory neurologic function following early intervention, stabilization, and definitive management. We analyzed the data on children and adolescents in whom traumatic atlanto-occipital dislocation had been treated with modern resuscitation techniques at our institution. METHODS: Atlanto-occipital dislocation is defined as disruption of the ligaments and other supporting soft tissues as indicated by displacement in either a transverse or vertical direction. With use of the Trauma Registry database at our institution, we identified sixteen such injuries that had occurred between 1986 and 2003. The hospital charts, clinic notes, and radiographs were reviewed. A careful neurological evaluation was performed for all of the survivors at the time of the latest follow-up. RESULTS: The mean age of the sixteen patients at the time of the injury was 7.6 years. The mechanisms of injury were diverse. The mean Glasgow Coma Scale score was 7.4 points. Eleven of the sixteen patients underwent intubation in the field, two were intubated in the emergency department, and three were not intubated. Eight of the sixteen patients were declared dead on arrival in the emergency department. The eight surviving patients initially were immobilized with either a halo vest or another orthosis. All patients except one received intravenous steroids in the emergency department. Three of the patients who survived the initial injury subsequently died while undergoing neurosurgical procedures for the treatment of extensive intracranial injuries. Four of the remaining five survivors underwent occiput-C2 fusion, and one was managed with a Minerva cast. At the time of the final follow-up, at a mean of 4.2 years after the injury, one patient was neurologically normal, three had mild spastic hemiparesis and were very functional, and one had spastic quadriplegia and was ventilator-dependent. CONCLUSIONS: Prompt recognition and treatment of traumatic atlanto-occipital dislocation in children and adolescents can result in improved survival. Early diagnosis, prompt intubation, early and adequate immobilization of the head and neck, and the use of intravenous steroids appear to facilitate survival. We recommend arthrodesis from the occiput to C2 (or the nearest adjacent intact and stable vertebra caudad to C2) for all children who survive a traumatic atlanto-occipital dislocation, particularly those with an incomplete spinal cord injury.

Adolescent↗