PURPOSE/AIM 1. To illustrate the normal anatomy of the sacroiliac joint by various imaging modali... more PURPOSE/AIM 1. To illustrate the normal anatomy of the sacroiliac joint by various imaging modalities. 2. To illustrate multi-modality imaging findings of sacroiliitis, including inflammatory, infectious and metabolic etiologies. CONTENT ORGANIZATION 1. Review the normal radiographic, computed tomography (CT), magnetic resonance imaging (MRI) and scintigraphic appearance of the sacroiliac joint. 2. Show imaging features of the various types of sacroiliitis by these same imaging modalities. SUMMARY The sacroiliac joint can be affected by degenerative arthritis, as well as by the inflammatory seronegative spondyloarthropathies including ankylosing spondylitis, reactive arthritis and psoriatic arthritis. Infection (by both bacterial and atypical organisms) and metabolic diseases can affect this joint. Imaging features of the normal sacroiliac joint and of sacroiliitis will be illustrated utilizing radiography, computed tomography, magnetic resonance imaging and bone scintigraphy.
Two steroidal ketones, delta-4-cholesten-3-one and delta-3,-5-cholestadiene-7-one, were isolated ... more Two steroidal ketones, delta-4-cholesten-3-one and delta-3,-5-cholestadiene-7-one, were isolated and identified for the first time in anhydrous milk fat and in nonfat dry milk. Together with these, two isoprenoid alcohols, phytol and dihydrophytol, were identified in anhydrous milk fat. Their identities were established on the basis of chromatographic and mass spectral data and confirmed by comparison with authentic materials.
The tensioned locking plate technique takes advantage of two fracture healing modalities. A direc... more The tensioned locking plate technique takes advantage of two fracture healing modalities. A direct healing effect from osteon bridging due to lag screw compression is combined with axial and angular stability provided by a locking plate construct.
Simultaneous anterior and posterior hip dislocation is an unusual injury. A unique case is presen... more Simultaneous anterior and posterior hip dislocation is an unusual injury. A unique case is presented, consisting of bilateral asymmetric hip dislocation with associated femoral head, femoral shaft, and acetabular fractures resulting from a motorcycle collision. The mechanisms of injury, management, role of imaging, and complications of this injury complex are discussed, with a review of the relevant literature.
Journal of applied biomaterials : an official journal of the Society for Biomaterials, 1994
Strain transfer near hydroxyapatite (HA) coated canine hip implants was examined using simulated ... more Strain transfer near hydroxyapatite (HA) coated canine hip implants was examined using simulated anatomical loading based on in vivo strain measurements. Strain changes near implants relative to intact control values were in excess of 100% for transverse and principal strains for zero time period (immediate postimplant) specimens. They were generally smaller (100% or less) for axial, transverse, and principal minimums in the same locations for 4 months postimplantation specimens. Cortical bone loss occurred in all implanted femora. The most extensive loss, up to 47%, occurred adjacent to the proximal section of the implant. Extensive trabecular bone formation, over 300% in some regions of each femur, was noted in all implanted femora. Backscattered electron imaging along the HA-coated sections of the implants showed extensive bone bonded to the coating. NOrmal light and UV light micrographs showed direct bone apposition to the implant surfaces and extensive bone formation in all tes...
American journal of orthopedics (Belle Mead, N.J.), 2013
We present a 19-year-old collegiate athlete who sustained a low-energy closed tibial shaft fractu... more We present a 19-year-old collegiate athlete who sustained a low-energy closed tibial shaft fracture. Following closed reduction, the dorsalis pedis and posterior tibial pulses were symmetric to the contralateral limb on physical examination. Angiography later confirmed triple vessel arterial disruption complicated by delayed ischemia requiring limb revascularization. Lower extremity triple vessel occlusion from a low-energy injury is rare, and delayed presentation requiring limb salvage is even more unusual. We review the literature, describe the diagnosis and treatment, and propose a strategy for post-fracture reduction management of vascular status.
Joint arthroplasty is the most frequently performed orthopedic procedure after fracture fixation.... more Joint arthroplasty is the most frequently performed orthopedic procedure after fracture fixation. The major indications for any joint replacement are degenerative joint disease, inflammatory arthropathy, avascular necrosis, and complicated fractures. The major contraindications for any joint arthroplasty are systemic and joint infection and a neuropathic joint. The interpretation of radiographs in cases of joint arthroplasty is a significant part of many radiology practices, and correct recognition of the prosthetic devices and their complications by the radiologist is important. The article reviews the most common types of joint arthroplasties and prostheses of the upper and lower extremities and discusses the most frequent complications associated with their placement.
The basic goal of fracture fixation is to stabilize the fractured bone, to enable fast healing of... more The basic goal of fracture fixation is to stabilize the fractured bone, to enable fast healing of the injured bone, and to return early mobility and full function of the injured extremity. Fractures can be treated conservatively or with external and internal fixation. Conservative fracture treatment consists of closed reduction to restore the bone alignment. Subsequent stabilization is then achieved with traction or external splinting by slings, splints, or casts. Braces are used to limit range of motion of a joint. External fixators provide fracture fixation based on the principle of splinting. There are three basic types of external fixators: standard uniplanar fixator, ring fixator, and hybrid fixator. The numerous devices used for internal fixation are roughly divided into a few major categories: wires, pins and screws, plates, and intramedullary nails or rods. Staples and clamps are also used occasionally for osteotomy or fracture fixation. Autogenous bone grafts, allografts, and bone graft substitutes are frequently used for the treatment of bone defects of various causes. For infected fractures as well as for treatment of bone infections, antibiotic beads are frequently used.
The Journal of Trauma Injury Infection and Critical Care, May 1, 2003
The most biomechanically stable relationship between the side plate of a compression hip screw (C... more The most biomechanically stable relationship between the side plate of a compression hip screw (CHS) and retrograde intramedullary (IM) femoral nail has not been described in the literature. This becomes a clinical issue when treating supracondylar femur fractures with a retrograde nail in patients with a history of compression hip screw fixation of intertrochanteric fractures. The proximal end of the nail and the interlocking screws may act as a stress riser in the femoral diaphysis. The purpose of this study is to determine the biomechanical consequences of the amount of implant overlap between a CHS plate and retrograde IM femoral nail. Nine paired fresh-frozen cadaver femora from elderly donors were cleaned of soft tissue and fixed with uniaxial strain gauges. Each femur was loaded three times in a fall-loading configuration to 50 kg at a rate of 1 Hz. The study consisted of two phases. In phase 1, six pair were randomly divided into a control and test femur from each pair. Three states were compared on each test femur: uninstrumented, instrumented with CHS, and instrumented with CHS and retrograde nail. The control femur consisted of the matched femur tested in two states: uninstrumented and instrumented with a CHS. The femora were then loaded to failure. The tests were performed with the retrograde nail and CHS gapped 3 cm, kissing, and overlapping by two screw holes (two pair for each state). In phase 2, each of the remaining three pair were instrumented with a CHS and retrograde nail overlapping in one femur and gapped in the matched femur and tested in the same manner. Data analysis was performed using Pearson's correlation coefficients between groups. Paired samples t tests were used to compare differences within test states and independent samples t tests were used to compare differences between femora. Mean strain at 50-kg load, load-versus-strain patterns, failure patterns, and load and strain at failure were recorded. RESULTS; Correlation coefficients were greater than 0.98 within and between pairs (p < 0.001). There were statistically significant differences (p < 0.05) in strain patterns between the uninstrumented, CHS, and CHS/IM test states. The addition of a side plate significantly (p < 0.05) increased lateral compressive strains in the femoral diaphysis. Mean strain at 50-kg load was significantly (p < 0.05) altered by the addition of the retrograde nail in all three implant orientations. Gapped implants failed at lower loads and strains than femurs with kissing and overlapping implants. Gapped constructs failed at lower loads than control states. Overlapped constructs tolerated the highest loads and strains before failure. Strain patterns are altered by the degree of implant overlap in the proximal femoral diaphysis. Femora with uninstrumented intervals between retrograde nails and side plates fail at lower loads than femora without retrograde nails and those with kissing or overlapping implants. Kissing or overlapping instrumentation increases load to failure and creates a more biomechanically stable construct than gapped implants. The findings of this study suggest an overlapping implant orientation in the femur increases failure load at the implant interface.
Fractures of the distal humerus involving the articular surface can be challenging. The complexit... more Fractures of the distal humerus involving the articular surface can be challenging. The complexity of these fracture patterns increases when the distal fracture is associated with a concomitant humeral shaft fracture with significant proximal extension. The combined exposure technique described here allows for consistent and controlled posterior humeral exposure proximally from the traverse of the axillary nerve to the distal trochlear tip. It is especially useful for complex segmental fracture patterns where distal intra-articular involvement is present and a single approach is desired.
PURPOSE/AIM 1. To illustrate the normal anatomy of the sacroiliac joint by various imaging modali... more PURPOSE/AIM 1. To illustrate the normal anatomy of the sacroiliac joint by various imaging modalities. 2. To illustrate multi-modality imaging findings of sacroiliitis, including inflammatory, infectious and metabolic etiologies. CONTENT ORGANIZATION 1. Review the normal radiographic, computed tomography (CT), magnetic resonance imaging (MRI) and scintigraphic appearance of the sacroiliac joint. 2. Show imaging features of the various types of sacroiliitis by these same imaging modalities. SUMMARY The sacroiliac joint can be affected by degenerative arthritis, as well as by the inflammatory seronegative spondyloarthropathies including ankylosing spondylitis, reactive arthritis and psoriatic arthritis. Infection (by both bacterial and atypical organisms) and metabolic diseases can affect this joint. Imaging features of the normal sacroiliac joint and of sacroiliitis will be illustrated utilizing radiography, computed tomography, magnetic resonance imaging and bone scintigraphy.
Two steroidal ketones, delta-4-cholesten-3-one and delta-3,-5-cholestadiene-7-one, were isolated ... more Two steroidal ketones, delta-4-cholesten-3-one and delta-3,-5-cholestadiene-7-one, were isolated and identified for the first time in anhydrous milk fat and in nonfat dry milk. Together with these, two isoprenoid alcohols, phytol and dihydrophytol, were identified in anhydrous milk fat. Their identities were established on the basis of chromatographic and mass spectral data and confirmed by comparison with authentic materials.
The tensioned locking plate technique takes advantage of two fracture healing modalities. A direc... more The tensioned locking plate technique takes advantage of two fracture healing modalities. A direct healing effect from osteon bridging due to lag screw compression is combined with axial and angular stability provided by a locking plate construct.
Simultaneous anterior and posterior hip dislocation is an unusual injury. A unique case is presen... more Simultaneous anterior and posterior hip dislocation is an unusual injury. A unique case is presented, consisting of bilateral asymmetric hip dislocation with associated femoral head, femoral shaft, and acetabular fractures resulting from a motorcycle collision. The mechanisms of injury, management, role of imaging, and complications of this injury complex are discussed, with a review of the relevant literature.
Journal of applied biomaterials : an official journal of the Society for Biomaterials, 1994
Strain transfer near hydroxyapatite (HA) coated canine hip implants was examined using simulated ... more Strain transfer near hydroxyapatite (HA) coated canine hip implants was examined using simulated anatomical loading based on in vivo strain measurements. Strain changes near implants relative to intact control values were in excess of 100% for transverse and principal strains for zero time period (immediate postimplant) specimens. They were generally smaller (100% or less) for axial, transverse, and principal minimums in the same locations for 4 months postimplantation specimens. Cortical bone loss occurred in all implanted femora. The most extensive loss, up to 47%, occurred adjacent to the proximal section of the implant. Extensive trabecular bone formation, over 300% in some regions of each femur, was noted in all implanted femora. Backscattered electron imaging along the HA-coated sections of the implants showed extensive bone bonded to the coating. NOrmal light and UV light micrographs showed direct bone apposition to the implant surfaces and extensive bone formation in all tes...
American journal of orthopedics (Belle Mead, N.J.), 2013
We present a 19-year-old collegiate athlete who sustained a low-energy closed tibial shaft fractu... more We present a 19-year-old collegiate athlete who sustained a low-energy closed tibial shaft fracture. Following closed reduction, the dorsalis pedis and posterior tibial pulses were symmetric to the contralateral limb on physical examination. Angiography later confirmed triple vessel arterial disruption complicated by delayed ischemia requiring limb revascularization. Lower extremity triple vessel occlusion from a low-energy injury is rare, and delayed presentation requiring limb salvage is even more unusual. We review the literature, describe the diagnosis and treatment, and propose a strategy for post-fracture reduction management of vascular status.
Joint arthroplasty is the most frequently performed orthopedic procedure after fracture fixation.... more Joint arthroplasty is the most frequently performed orthopedic procedure after fracture fixation. The major indications for any joint replacement are degenerative joint disease, inflammatory arthropathy, avascular necrosis, and complicated fractures. The major contraindications for any joint arthroplasty are systemic and joint infection and a neuropathic joint. The interpretation of radiographs in cases of joint arthroplasty is a significant part of many radiology practices, and correct recognition of the prosthetic devices and their complications by the radiologist is important. The article reviews the most common types of joint arthroplasties and prostheses of the upper and lower extremities and discusses the most frequent complications associated with their placement.
The basic goal of fracture fixation is to stabilize the fractured bone, to enable fast healing of... more The basic goal of fracture fixation is to stabilize the fractured bone, to enable fast healing of the injured bone, and to return early mobility and full function of the injured extremity. Fractures can be treated conservatively or with external and internal fixation. Conservative fracture treatment consists of closed reduction to restore the bone alignment. Subsequent stabilization is then achieved with traction or external splinting by slings, splints, or casts. Braces are used to limit range of motion of a joint. External fixators provide fracture fixation based on the principle of splinting. There are three basic types of external fixators: standard uniplanar fixator, ring fixator, and hybrid fixator. The numerous devices used for internal fixation are roughly divided into a few major categories: wires, pins and screws, plates, and intramedullary nails or rods. Staples and clamps are also used occasionally for osteotomy or fracture fixation. Autogenous bone grafts, allografts, and bone graft substitutes are frequently used for the treatment of bone defects of various causes. For infected fractures as well as for treatment of bone infections, antibiotic beads are frequently used.
The Journal of Trauma Injury Infection and Critical Care, May 1, 2003
The most biomechanically stable relationship between the side plate of a compression hip screw (C... more The most biomechanically stable relationship between the side plate of a compression hip screw (CHS) and retrograde intramedullary (IM) femoral nail has not been described in the literature. This becomes a clinical issue when treating supracondylar femur fractures with a retrograde nail in patients with a history of compression hip screw fixation of intertrochanteric fractures. The proximal end of the nail and the interlocking screws may act as a stress riser in the femoral diaphysis. The purpose of this study is to determine the biomechanical consequences of the amount of implant overlap between a CHS plate and retrograde IM femoral nail. Nine paired fresh-frozen cadaver femora from elderly donors were cleaned of soft tissue and fixed with uniaxial strain gauges. Each femur was loaded three times in a fall-loading configuration to 50 kg at a rate of 1 Hz. The study consisted of two phases. In phase 1, six pair were randomly divided into a control and test femur from each pair. Three states were compared on each test femur: uninstrumented, instrumented with CHS, and instrumented with CHS and retrograde nail. The control femur consisted of the matched femur tested in two states: uninstrumented and instrumented with a CHS. The femora were then loaded to failure. The tests were performed with the retrograde nail and CHS gapped 3 cm, kissing, and overlapping by two screw holes (two pair for each state). In phase 2, each of the remaining three pair were instrumented with a CHS and retrograde nail overlapping in one femur and gapped in the matched femur and tested in the same manner. Data analysis was performed using Pearson's correlation coefficients between groups. Paired samples t tests were used to compare differences within test states and independent samples t tests were used to compare differences between femora. Mean strain at 50-kg load, load-versus-strain patterns, failure patterns, and load and strain at failure were recorded. RESULTS; Correlation coefficients were greater than 0.98 within and between pairs (p < 0.001). There were statistically significant differences (p < 0.05) in strain patterns between the uninstrumented, CHS, and CHS/IM test states. The addition of a side plate significantly (p < 0.05) increased lateral compressive strains in the femoral diaphysis. Mean strain at 50-kg load was significantly (p < 0.05) altered by the addition of the retrograde nail in all three implant orientations. Gapped implants failed at lower loads and strains than femurs with kissing and overlapping implants. Gapped constructs failed at lower loads than control states. Overlapped constructs tolerated the highest loads and strains before failure. Strain patterns are altered by the degree of implant overlap in the proximal femoral diaphysis. Femora with uninstrumented intervals between retrograde nails and side plates fail at lower loads than femora without retrograde nails and those with kissing or overlapping implants. Kissing or overlapping instrumentation increases load to failure and creates a more biomechanically stable construct than gapped implants. The findings of this study suggest an overlapping implant orientation in the femur increases failure load at the implant interface.
Fractures of the distal humerus involving the articular surface can be challenging. The complexit... more Fractures of the distal humerus involving the articular surface can be challenging. The complexity of these fracture patterns increases when the distal fracture is associated with a concomitant humeral shaft fracture with significant proximal extension. The combined exposure technique described here allows for consistent and controlled posterior humeral exposure proximally from the traverse of the axillary nerve to the distal trochlear tip. It is especially useful for complex segmental fracture patterns where distal intra-articular involvement is present and a single approach is desired.
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