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Biomedical subjects

Craig S Roberts

Publications and source records attributed to Craig S Roberts.

At least 19 recordsLinked to original sources
PubMed2006

Scapular thickness--implications for fracture fixation.

The purpose of this study was to measure and map scapula osseous thickness to identify the optimal areas for internal fixation. Eighteen (9 pairs) scapulae from 2 female and 7 male cadavers were used. After harvest and removal of all soft tissues, standardized measurement lines were made based on anatomic landmarks. For consistency among scapulae, measurements were taken at standard percentage intervals along each line approximating the distance between two consecutive reconstruction plate screw holes. Two-mm-diameter drill holes were made at each point, and a standard depth gauge was used to measure thickness. The glenoid fossa (25 mm) displayed the greatest mean osseous thickness, followed by the lateral scapular border (9.7 mm), the scapula spine (8.3 mm), and the central portion of the body of the scapula (3.0 mm). To optimize screw purchase and internal fixation strength, the lateral border, the lateral aspect of the base of the scapula spine, and the scapula spine itself should be used for anatomic sites of internal fixation of scapula fractures.

Aged↗
PubMed2006

Correlating weather and trauma admissions at a level I trauma center.

BACKGROUND: Popular emergency room wisdom touts higher temperatures, snowfall, weekends, and evenings as variables that increase trauma admissions. This study analyzed the possible correlation between trauma admissions and specific weather variables, and between trauma admissions and time of day or season. METHODS: Trauma admission data from a Level I trauma center database from July 1, 1996 to January 31, 2002 was downloaded and linked with local weather data from the Archives of the National Oceanic and Atmospheric Administration website, and then analyzed. RESULTS: There were 8,269 trauma admissions over a total of 48,984 hours for an average of one admission every 6 hours. Daily high temperature and precipitation were valid predictors of trauma admission volume, with a 5.25% increase in hourly incidents for each 10-degree difference in temperature, and a 60% to 78% increase in the incident rate for each inch of precipitation in the previous 3 hours. CONCLUSIONS: Weather and seasonal variations affect admissions at a Level I trauma center. Data from this study could be useful for determining staffing requirements and resource allocation.

Humans↗
PubMed2006

The trochanteric nail versus the sliding hip screw for intertrochanteric hip fractures: a review of 93 cases.

BACKGROUND: The trochanteric nail, a redesigned short gamma nail, (Howmedica, Rutherford, NJ) was introduced in the United States during 1998 for the treatment of intertrochanteric fractures. METHODS: We retrospectively reviewed 93 patients who were treated for an intertrochanteric fracture with either a sliding hip screw (SHS) or the short trochanteric nail (TN). RESULTS: In all, 94% of the patients in the sliding hip screw group healed without complication. There was one case of femoral head necrosis, one lag screw cutout, and one hardware removal for pain. Eighty-nine percent of the patients in the trochanteric nail group healed without complication. There was one late fracture at the tip of the nail, three cases of lag screw cutout, and one nonunion. CONCLUSIONS: This study suggests that the trochanteric nail is a reasonable alternative to the sliding hip screw when used for intertrochanteric fractures, although it may be associated with higher complication rates.

Aged↗
PubMed2005

Implant retention and removal after internal fixation of the symphysis pubis.

Although internal fixation of diastasis of the symphysis pubis is commonly performed, there are no clear guidelines regarding the indications for removal of these implants. The long-term physiologic effects of retaining these internal fixation devices are not well described. We surveyed the literature to assess the current thinking and recommendations regarding implant retention and removal. Twenty-four case series and two case reports were found, for a total of 482 cases. Complications arose as a result of implant retention in 7.5% of patients, with infection the most common complication. There is no consensus in the literature regarding implant retention and removal after internal fixation of diastasis of the symphysis pubis.

Device Removal↗
PubMed2005

The effect of transfixion wire crossing angle on the stiffness of fine wire external fixation: a biomechanical study.

To analyse the effect of transfixion wire-crossing angle on the stiffness of fine wire external fixation, a laboratory investigation using a fibreglass tibia fixed into an idealised fixator was performed with a servohydraulic test frame. Load-deformation behaviour was compared at the different wire-crossing angles (30 degrees -90 degrees ) under identical conditions of central axial compression, medial compression-bending, posterior compression-bending, posteromedial compression-bending, and torsion. Stiffness values were calculated from the load-deformation and torque-angle curves. The increase in wire-crossing angle led to an overall increase in the stiffness, except medial bending stiffness. The wire-crossing angle of 90 degrees provided significantly greater stiffness than all other angles in all load configurations (p<0.05) except medial bending. In medial bending, the wire-crossing angle of 30 degrees provided significantly greater stiffness than all the other angles (p<0.05). Increasing wire-crossing angle from 30 degrees to 90 degrees contributed to an overall increase of 75% in external fixation stiffness, which included axial, torsional, and bending stiffness, but bending stiffness was a function of the wire positioning with respect to the loading axis. Therefore, using the widest possible wire-crossing angle and placing wires as close to the loading plane as possible can increase the stiffness of external fixation.

Biomechanical Phenomena↗
PubMed2005

The effect of wire plane tilt and olive wires on proximal tibia fracture fragment stability and fracture site motion.

To analyze the effect of the tilt angle relationship between the crossed wire plane and the bone axis on the stiffness of fine wire external fixation, load-deformation behavior was compared across different tilt angles (0 degree, 10 degrees, and 20 degrees) of the plane containing crossed smooth or olive wires under identical conditions of central axial compression, medial compression-bending, posterior compression-bending, posteromedial compression-bending, and torsion. Stiffness values were calculated from the load-deformation and torque-angle curves. A tilt angle of 20 degrees with olive wires provided significantly greater stiffness compared to smooth wires at any angle in any loading condition (p < 0.05). A tilt angle of 20 degrees with olive wires was also significantly more stiff than a tilt angle of 0 degree with olive wires in any loading condition. In torsion, olive wires with 10 degrees and 20 degrees tilt were not significantly different, while in posterior bending olive wires with 10 degrees tilt were significantly stiffer than olive wires with 0 degree or 20 degrees tilt. With smooth wires, tilting the wire plane caused a decrease in stiffness in posterior bending, posteromedial bending, and torsion. Overall, the use of olive wires in conjunction with tilting the wire plane enhances the fixation stiffness for proximal tibia fractures while allowing more options for wire configurations that avoid neurovascular and musculotendinous structures, and wounds.

External Fixators↗
PubMed2005

The effect of transfixion wire number and spacing between two levels of fixation on the stiffness of proximal tibial external fixation.

OBJECTIVES: Anatomic constraints about the proximal tibia limit the ability to insert wires at the biomechanically optimum angle of 90 degrees, thus diminishing the potential stability of external fixators used for proximal tibial fractures. To overcome this problem, surgeons use more than 2 wires at a single level of fixation or a second level of fixation. This study evaluated the effect of transfixion wire number and placement of a second level of fixation on the stiffness of proximal tibial external fixation. METHODS: A fiberglass tibia fixed into an idealized ring external frame was tested. Load-deformation behavior was compared among the different wire numbers (1 level with 2, 3, 4, and 5 wires) and placement of a second level of fixation (2 wires first level and 1 wire second level, and 2 wires first level and 2 wires second level) at 2, 3, 4, 5, 6, 7, 8, 9, and 10 cm distance from the first level of fixation. Identical loading conditions of central axial compression, medial compression-bending, posterior compression-bending, posteromedial compression-bending, and torsion were used. Stiffness values were calculated from the load-displacement and the torque-angle curves. RESULTS: An increase in wire number at 1 level led to an overall increase in stiffness, whereas the addition of a second level of fixation and increased spread between these 2 levels increased bending stiffness. CONCLUSIONS: The addition of a second level of external fixation of the proximal tibia fragment with maximum possible distance between the 2 levels increases bending stiffness, whereas increasing the number of transfixion wires increases overall stiffness. Axial and torsional stiffness is proportional to the total number of wires regardless of the number of levels of fixation.

Biomechanical Phenomena↗
PubMed2005

Knee dislocation with ipsilateral femoral shaft fracture: a report of five cases.

We report the management and outcome of 4 patients with 5 knee dislocations associated with ipsilateral femoral shaft fractures. All patients were managed by immediate reduction of the knee dislocation, intramedullary nailing of the femur, and angiography, followed by postoperative immobilization of the knee (brace or external fixation) for a minimum of 6 weeks. Four of the 5 dislocations underwent a secondary ligament reconstruction. At the 2-year follow up, the mean Knee Society Score was 133 (range 99-170).

Adult↗
PubMed2005

Toxicology screening in orthopedic trauma patients predicting duration of prescription opioid use.

Following hospitalization for orthopedic trauma, some patients continue to use opioids following fracture healing. This retrospective cohort study of 50 patients with high-energy fractures was conducted to determine if toxicology screening tests upon admission can predict subsequent opioid use. Data were collected from clinical records and a statewide electronic database of prescription records. Six months following hospital discharge, those with positive toxicology used more Following hospitalization for orthopedic trauma, some patients continue to use opioids following fracture healing. This retrospective cohort study of 50 patients with high-energy fractures was conducted to determine if toxicology screening tests upon admission can predict subsequent opioid use. Data were collected from clinical records and a statewide electronic database of prescription records. Six months following hospital discharge, those with positive toxicology used more. Following hospitalization for orthopedic trauma, some patients continue to use opioids following fracture healing. This retrospective cohort study of 50 patients with high-energy fractures was conducted to determine if toxicology screening tests upon admission can predict subsequent opioid use. Data were collected from clinical records and a statewide electronic database of prescription records. Six months following hospital discharge, those with positive toxicology used more opioids (730 mg vs. 364 mg; P = .04) expressed as morphine equivalents than those with negative toxicology and were more likely to continue using opiates at the end of the 3rd, 4th, 5th, and 6th month after discharge. Patients hospitalized for high-energy fractures with positive admission toxicology are at risk for prolonged opiate use during the initial six months following discharge.

Adult↗
PubMed2005

Damage control orthopaedics: evolving concepts in the treatment of patients who have sustained orthopaedic trauma.

In some groups of polytrauma patients, particularly those with chest injuries, head injuries, and those with mangled extremities, early total care of major bone fractures may be potentially harmful. Delaying all orthopaedic surgery, however, is also not always the best approach. In these situations, damage control orthopaedics, which emphasizes the stabilization and control of the injury rather than repair will add little additional physiologic insult to the patient and is a treatment option that should be considered.

Fracture Fixation↗
PubMed2004

Incremental effectiveness of amlodipine besylate in the treatment of hypertension with single and multiple medication regimens.

BACKGROUND: The objective of this retrospective observational analysis is to examine the clinical effectiveness of amlodipine besylate as monotherapy or in combination with other antihypertensive drugs (AHDs) in systolic blood pressure (BP) control and BP goal attainment, according to the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC) 6, JNC 7, and American Diabetes Association (ADA)recommendations, within a multicenter ambulatory care setting. METHODS: Hypertensive adults (n = 1175) were identified during a 4-year period (1998 to 2001) from a large commercially available electronic medical record (EMR) database. Patients were required to have initiated therapy with amlodipine and have at least one BP measurement within 6 months before, and 12 months after, the medication start date. Patients were divided into cohorts based on the number of AHDs used before, and continued through, the initiation of amlodipine. Mean change in systolic BP was compared from pre- to post-amlodipine, and adjusted change in systolic BP was calculated using multivariate regression. The percentage of patients attaining BP goal was also calculated. RESULTS: In the order of increasing number of AHDs before initiation of amlodipine (0, 1, 2, > or = 3 previous AHDs): adjusted systolic BP change in mm Hg was -16.1 (95% confidence interval [CI]: -17.9, -14.3), -17.6 (95% CI: -19.6, -15.5), -16.7 (95% CI: -19.0, -14.5), and -15.7 (95% CI: -18.7, -12.8), respectively; BP goal attainment was 39%, 45%, 41%, and 45%, respectively. Amlodipine initiation in all regimens showed statistically significant incremental systolic BP reduction and BP goal attainment from baseline (P < .001). CONCLUSIONS: This study suggests that amlodipine besylate is effective alone or as an add-on therapy to diverse classes of agents.

Aged↗
PubMed2004

The accuracy of fine wire tensioners: a comparison of five tensioners used in hybrid and ring external fixation.

OBJECTIVES: To compare the accuracy of 5 commonly available fine wire tensioners used in hybrid and ring external fixation. DESIGN: A laboratory investigation. SETTING: The testing of 5 commonly available tensioners was performed with a servohydraulic test frame (MTS Bionix 858, Minneapolis, MN). MAIN OUTCOME MEASUREMENT: The real wire tension data of each tensioner provided by the MTS were compared with corresponding nominal values. The percent error for each tensioner was calculated. Clinical ease of usage of the wire tensioners was also evaluated. RESULTS: The EBI tensioner was the most accurate (-0.17% to 0.09% error). The Smith and Nephew tensioner had a -13.97% to -8.61% error, the How medica tensioner a -12.48% to -10.86% error, and the Synthes tensioner a -0.2% to 24.28% error. The DePuyACE tensioner was the least accurate, with errors ranging from -36.76% to -30.92%. The Howmedica tensioner was the easiest to use, followed by the Smith and Nephew tensioner, the DePuyACE tensioner, the Synthes tensioner, and the EBI tensioner. CONCLUSIONS: Most commonly available tensioners tend to undertension. Future efforts should focus on the development of wire tensioners that combine accuracy and ease of usage.

Bone Wires↗
PubMed2004

Treatment patterns in the months prior to and after asthma-related emergency department visit.

BACKGROUND: There are 2 million asthma-related emergency department (ED) events each year in the United States. The underrecognition and undertreatment of asthma is believed to be associated with this high level of morbidity. This study was designed to describe the treatment patterns in the year prior to the ED event and for 2 months after the event. METHODS: This retrospective observational study utilized an integrated managed care database that contained administrative claims from > 20 managed care plans across the United States. All patients with at least one ED visit for asthma during 2001 were included. Patients were required to have data available 12 months prior to and 2 months following the ED visit of interest, and were excluded if they had made an asthma-related ED visit within 12 months of the identified event. RESULTS: There were 12,636 patients identified with an asthma-related ED visit. In the year prior to the ED event, 25.1% of the patients received an inhaled corticosteroid (ICS), 29.9% received an oral corticosteroid (OCS), and 53.5% received a short-acting beta-agonist (SABA). Overall, there were three albuterol units dispensed for every ICS unit dispensed in the 12-month period prior to the ED event. Ninety-four percent of patients had made an office visit in the prior year, but only 13.3% underwent spirometry testing. Prescriptions dispensed for ICSs and OCSs increased 2.6-fold and 7.5-fold, respectively, in the month after the ED event, and dispensing rates reverted approximately to baseline rates by the second month after the index ED event. CONCLUSION: This study demonstrates the dependence of this population on the use of rescue medications, including SABA and OCS, to treat their asthma. Furthermore, the ED event resulted in only an incremental short-term improvement in ICS-containing controller treatment.

Administration, Inhalation↗
PubMed2003

Occult bilateral acetabular fractures associated with high-energy trauma and osteoporosis.

Acetabular fractures that are radiographically occult are associated with osteoporosis, low-energy trauma, and advanced age. We present a case of bilateral occult acetabular fractures in a 65-year-old woman who presented with an open tibia-fibula fracture and compartment syndrome and thoracolumbar spine fractures sustained in a motor vehicle accident. Initial radiographs of the pelvis and a pelvic CT scan did not show any bony injuries when the films were reviewed prospectively. At 6 weeks after injury, a CT scan and plain radiographs showed bilateral healing transverse acetabular fractures with acetabular protrusio on the left. At most recent follow-up, the patient had posttraumatic hip arthritis with moderate protrusio on the left and was ambulating with a cane. Total hip arthroplasty is anticipated in the future.

Accidents, Traffic↗
PubMed2003

Hybrid external fixation of the proximal tibia: strategies to improve frame stability.

OBJECTIVE: To determine the specific frame construction strategies that can increase the stability of hybrid (ring with tensioned wires proximally connected by bars to half-pins distally) external fixation of proximal tibia fractures. DESIGN Repeated measures biomechanical testing. SETTING: Laboratory. SPECIMENS: Composite fiberglass tibias. METHODS: Using the Heidelberg and Ilizarov systems, external fixators were tested on composite fiberglass tibias with a 1-cm proximal osteotomy (OTA fracture classification 41-A3.3) in seven frame configurations: unilateral frames with 5-mm diameter half-pins and 6-mm diameter half-pins; hybrid (as described above), with and without a 6-mm anterior proximal half-pin; a "box" hybrid (additional ring group distal to the fracture connected by symmetrically spaced bars to the proximal rings) with and without an anterior, proximal half-pin; and a full, four-ring configuration. Each configuration was loaded in four positions (central, medial, posterior, and posteromedial). MAIN OUTCOME MEASUREMENTS: Displacement at point of loading of proximal fragment. RESULTS: The "box" hybrid was stiffer than the standard hybrid for all loading positions. The addition of an anterior half-pin stiffened the standard hybrid and the "box" hybrid. CONCLUSIONS: The most dramatic improvements in the stability of hybrid frames used for proximal tibial fractures result from addition of an anterior, proximal half-pin.

Biomechanical Phenomena↗
PubMed2003

Pin tract infection with contemporary external fixation: how much of a problem?

OBJECTIVE: To determine the incidence of pin tract infection.DESIGN Retrospective chart review. SETTING: Level 1 trauma center in an urban community. PATIENTS: A total of 285 patients with 285 fractures over a 4-year period (1997-2001). INTERVENTION: External fixation. MAIN OUTCOME MEASUREMENT: Incidence of pin tract infection. RESULTS: Of 285 fractures, 32 (11.2%) were complicated by infection. The incidence of infection according to montage was 3.9% (3/77) for ring fixators, which was significantly different (P < 0.04) from the 12.9% incidence (23/178) for unilateral fixators and the 20.0% incidence (6/30) for hybrid fixators (P = 0.004). The incidences of pin tract infection for the unilateral fixator group and the hybrid fixator group were not significantly different. CONCLUSIONS: Patients with hybrid external fixators had a similar risk of pin tract infection as patients who had unilateral fixators. The infection rate in the ring fixator group was significantly lower than the hybrid external and unilateral fixator groups.

Adolescent↗