Biomedical subjects

Brandon D Lawrence

Publications and source records attributed to Brandon D Lawrence.

5 recordsLinked to original sources

PubMed2005

Complete exposure of the articular surface for fixation of patellar fractures.

Anterior tension band fixation constructs are among the mainstay of treatment of patella fractures and lead to reliable results with simple transverse fracture patterns. However, comminuted fractures of the patella require much more extensive articular reconstruction than interdigitating two large fragments to achieve a good result. In this report, we describe a technique for exposure, reduction, and stabilization of patella fractures that allows for direct visual reduction of the articular surface. Subsequent devices are applied directly to the bony surfaces of the patella without soft-tissue interposition, which distinguishes it from traditional approaches. This technique may be used to ensure articular surface congruity in simple transverse fractures and may be particularly useful in comminuted fractures when patellar excision would otherwise be considered.

Adult↗

PubMed2005

Treatment of intertrochanteric hip fractures with the AO trochanteric fixation nail.

Further biomechanical and clinical studies are necessary to validate the efficacy of the Trochanteric Fixation Nail, but in our experience this is an improvement over the currently available devices.

Bone Nails↗

PubMed2004

Complete cervical intervertebral disc extrusion with spinal cord injury in the absence of facet dislocation: a case report.

STUDY DESIGN: Complete cervical disc complex extrusion, defined as the extrusion of both cartilaginous end-plates, the entire nucleus pulposus, and portions of the anulus fibrosus, is rare. A case of complete cervical disc complex extrusion with spinal cord injury in the absence of facet dislocation or subluxation in an obtunded patient is reported. OBJECTIVE: To report an unusual presentation of spinal cord injury and the occurrence of complete traumatic cervical disc complex extrusion in the absence of facet dislocation and normal plain radiographic findings. SUMMARY OF BACKGROUND DATA: Traumatic cervical disc herniation occurs in 54% to 80% of patients with facet dislocation. A report of complete extrusion of a cervical intervertebral disc complex (cartilaginous endplate, anulus, and nucleus pulposus) with spinal cord injury in the absence of dislocation has not been described, to the best of the authors' knowledge. METHODS: A clinical and radiographic review of such a case of complete traumatic cervical disc complex herniation in the absence of dislocation was performed. RESULTS: Plain radiographic imaging did not show any injury. A nondisplaced fracture of the left inferior facet joint was evident on computed tomography. The diagnosis of C4-C5 intervertebral disc extrusion was made only after magnetic resonance imaging. The vacuum effect of complete disc extrusion created a "white-out" appearance to the disc space on the sagittal T2 magnetic resonance image. The patient underwent anterior cervical discectomy and fusion with additional posterior cervical fusion. He subsequently regained functional strength against gravity in two of four limbs. He remains completely paraparetic in the left upper extremity and partially paraparetic in the left lower extremity. CONCLUSION: The case report highlights the occurrence of complete traumatic cervical disc extrusion in the absence of facet dislocation with normal plain radiographic findings and consequent spinal cord injury, which can accompany such an injury.

Accidents, Traffic↗

PubMed2004

Surgical treatment of pediatric femoral shaft fractures.

PURPOSE OF REVIEW: Femoral shaft fractures are among the most common fractures in children. Depending on the patient's age, fracture location, pattern, mechanism of injury, and associated injuries, several different treatment options exist. The purpose of this review is to discuss these different clinical situations and the recommended treatment methods, as well as to characterize the latest literature and recommendations. RECENT FINDINGS: In the past several years, there have been significant changes in the approach to the treatment of pediatric femoral shaft fractures, particularly in school-aged children. Young children have traditionally been treated conservatively with good results, and this method is still currently advocated. Adolescents over the age of 12 are generally treated with rigid intramedullary rods. However, in children between the ages of 5 and 12, new surgical treatment modalities have been tested with good outcomes, and, as new data emerge, these methods are becoming preferable to conservative treatment. SUMMARY: Children who sustain femoral shaft fractures can present difficult challenges to both orthopedists and pediatricians. A recent shift in treatment in children between ages of 5 and 12 from nonoperative to surgical intervention has led to shorter hospital stays and earlier return to activity with reliable fracture healing.

Adolescent↗

PubMed2002

Functional polycystin-1 expression is developmentally regulated during epithelial morphogenesis in vitro: downregulation and loss of membrane localization during cystogenesis.

Polycystin-1 is a protein mutated in the majority of cases of autosomal dominant polycystic kidney disease (ADPKD), but its role in the molecular pathway of tubulogenesis and cystogenesis is not understood. To define the role of polycystin-1 during dynamic changes in formation of intercellular contacts and cell polarity accompanying epithelial morphogenesis, we have utilized a 3D MDCK in vitro model of tubulogenesis and cystogenesis. Here we demonstrate that polycystin-1 is a novel component of desmosomal junctions of epithelial cells. A striking downregulation of polycystin-1 mRNA was detected in cysts as compared to tubules, leading to altered protein expression and localization. While polycystin-1 is localized to basolateral membranes of MDCK tubules, it is only detected in cytoplasmic pools in cystic cells. Furthermore, the expression of polycystin-1 is modulated during distinct stages of HGF-induced tubulogenesis from MDCK cysts. Thus, polycystin-1 is not detected in intercellular contacts at early steps of tubulogenesis, but assumes its basolateral localization at the time of cell polarization and lumen formation. An important role of polycystin-1 is further demonstrated using the pancreatic ductal epithelial cell line SU.86.86 which undergoes in vitro differentiation resulting in the formation of domes. Dome formation is thought to parallel tubular differentiation and morphogenesis in vivo. Our data reveal significant upregulation of polycystin-1 mRNA and protein levels in domes. Collectively, our results demonstrate a critical importance of controlled level of polycystin-1 expression for proper tubular differentiation and maturation. We suggest that the loss of polycystin-1 from its basolateral location in tubular epithelium may alter critical pathways controlling normal tubulogenesis leading to cystic transformation.

Adherens Junctions↗