The purpose of this study was to determine the prevalence of non-accidental injury in toddlers (birth to two years old) presenting with a femur fracture to a single institution within a Western Canadian population. There are currently no Canadian studies that investigate this association in the medical literature. A retrospective case-control study was performed for children less than or equal to two years of age with a diagnosis of femur fracture who presented to a single institution from 1994 to 2005. Patients with associated pathological or metabolic bone disorders were excluded. The primary outcome measure was the prevalence of non-accidental injury associated with femur fracture. Secondary outcome measures included: patient demographics, injury characteristics, radiologic and other work-up, and suspicion of abuse. Statistical analysis was performed using tests of analysis of variance and multivariate analysis to identify independent and significant risk factors associated with non-accidental injury. One hundred twenty-seven children that met the inclusion criteria were identified. The overall prevalence of non-accidental injury was 11% (14/127 patients) and 17% (10/60 patients) in children under twelve months. Mean age was twelve months in the abused group and sixteen months in the accidental group. Forty-three percent of the abused group had delayed presentation compared to 8% of the accidental group. In the abused group, 43% had unknown, unwitnessed, inconsistent histories versus 4% in the accidental group. No specific fracture pattern or location suggestive for non-accidental injury was identified. Forty-three percent (6/14 patients) of the abused group and 12% (13/113 patients) of the accidental group had other injuries. Multivariate analysis determined that delayed presentation (p=0.001), mechanism of injury (p=0.02) and other associated injuries (p=0.003) were the only independently significant risk factors for abuse. Toddlers who present with femoral fracture are at risk for associated non-accidental injury though perhaps this risk is not as high as previously thought. Regardless, a high index of suspicion is mandatory when these children are encountered and careful screening with a thorough history, physical examination, and other investigations where indicated, are warranted to rule out associated child abuse.
The purpose of this study was to first determine if neuromuscular scoliosis results in greater peri-operative transfusion requirements compared to idiopathic scoliosis, and secondly to compare the effects of tranexamic acid (TXA) dosing on reducing transfusion requirements in scoliosis surgery. Previous studies have suggested that patients with neuromuscular scoliosis tend to have more blood loss during scoliosis corrective surgery as compared to patients with idiopathic scoliosis. Tranexamic acid has not been studied extensively in these populations and consensus regarding appropriate dosing has not yet been elucidated. A retrospective chart review of all patients who underwent posterior instrumentation and fusion for scoliosis for the years 1999 to 2006 was performed. Peri-operative transfusion requirements for idiopathic and neuromuscular scoliosis patients were compared and grouped according to TXA use. Transfusion requirements for those patients receiving either a low (10mg/kg loading, 1mg/kg/h infusion) or high (20mg/kg loading, 10mg/kg/h infusion) dose TXA were also compared. Idiopathic patients had significantly decreased transfusion requirements overall (no TXA: idiopathic 1028.3 ± 558.7ml vs. neuromuscular 1400.7 ± 911.3ml, p = 0.02; with TXA: idiopathic 1082.9 ± 1005.5ml vs. neuromuscular 2043.8 ± 1397.5ml, p = 0.03). In the idiopathic group, high dose TXA resulted in a significant reduction in peri-operative transfusion requirements compared to low dose TXA (687.9 ± 778.1ml vs. 1355.0 ± 965.8ml, p = 0.04). Neuromuscular scoliosis patients have significantly higher transfusion requirements as compared to idiopathic patients. For patients with idiopathic scoliosis, the use of the high dose TXA is suggested over low dose TXA given the relative reduction in transfusion requirements for the high dose group.
The purpose of this study was to determine contact patterns in cementless acetabular cups using a novel computed tomography (CT) scan analysis technique. Eighteen embalmed cadaveric hemipelvis specimens were randomly assigned to receive one of three cup designs. A custom CT platform was designed to optimize imaging of the acetabular cups. After cup implantation, specimens were mounted on the platform and imaged in a spiral CT scanner. Contact analysis was preformed using custom-developed imaging software. The hemisphere, dual geometry and spiked cup designs analyzed using this CT analysis technique demonstrate differences in the amount and distribution of bone pros-thesis contact. The purpose of this study was to determine contact patterns in cementless acetabular cups using computed tomography (CT) scan analysis. Eighteen embalmed cadaveric hemipelvis specimens were randomly assigned to receive a hemispherical cup, a dual geometry cup, or a spiked cup. After radiographic templating, an experienced orthopaedic team prepared the specimens and implanted the acetabular cups. A custom CT platform was designed to optimize imaging of the acetabular cups. After cup implantation, specimens were mounted on the platform and imaged in a spiral CT scanner. Contact analysis was preformed using custom-developed imaging software. Contact was defined as a bone-prosthesis distance of 0.5 mm or less. The mean amount of cup contact was 40.4% (SD=8.2%) in the hemisphere group, 24.7% (SD=2.3%) in the dual geometry group, and 29.7% (SD=9.5%) in the spiked group. Colour mapping of the bone-prosthesis gap was used to identify contact/non-contact regions along the acetabular contour for all cup designs. Preliminary work with this CT analysis technique demonstrates differences in the amount and distribution of contact in the acetabular cup designs. Future work will involve development of an imaging phantom to clarify error, use of the technique with different cup designs and reaming techniques, and comparison of this technique with conventional CT scan techniques. This study outlines a novel CT analysis technique for quantitatively determining bone-prosthesis contact for cementless acetabular cups. The hemisphere, dual geometry and spiked cup designs analyzed using this CT analysis technique demonstrate differences in the amount and distribution of bone prosthesis contact.
