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At least 253 records · Page 14Linked to original sources

PubMed2004

Should the donor radius be plated prophylactically after harvest of a radial osteocutaneous flap? A cost-effectiveness analysis.

The objective of this study was to assess the cost-effectiveness of prophylactic plating of the donor radius after harvest of a radial osteocutaneous flap. Costs were measured from a Ministry of Health perspective, and effectiveness in terms of quality adjusted life years (QALYs.) A literature search identified 22 studies reporting complications of radial osteocutaneous free flaps, and nine studies reporting complications of radius plating. The rates of the various complications were pooled to provide the probability of each clinically important complication. A decision analytic model was used to determine the total costs, and QALYs for each of the treatment options. The expected direct costs for prophylactic plating and treatment after fracture were $2071 and $140, respectively. The expected QALYs for prophylactic plating and treatment after fracture were 8.55 and 9.92, respectively. It was concluded that prophylactic plating of the donor radius is not a cost-effective approach when compared to the treatment of donor radius fractures after they occur.

Bone Plates↗

PubMed1960

Determination of equivalent pore radius for human red cells by osmotic pressure measurement.

A new method has been developed to measure the equivalent pore radius in cellular membranes, and has been applied to human red cells. When red cells are suddenly introduced into a non-isosmolar concentration of non-lipid-soluble non-electrolyte molecules, water will enter or leave the cell. The rate of cell swelling or shrinking is determined and extrapolated to zero time to give the initial rate of volume change. By suitable adjustment of the concentration of the external solution the initial rate may be brought to zero. The transient equilibrium concentration, determined by interpolation from experimental data, gives a measure of Staverman's reflection coefficient, sigma. The zero time method has enabled us to determine sigma for nine permeant molecules. sigma is directly related to the equivalent pore radius; the experimental data lead to a value of 4.2 A for the equivalent pore radius in man, in good agreement with the previous figure of 3.5 A given by Paganelli and Solomon. The zero time method offers a number of advantages over previous methods for determination of this parameter. It requires no measurement of the rate of water entrance into the cell, and is essentially independent of the kinetics of cell swelling. It may be applied to a variety of living cells so that many additional membranes may now be characterized in terms of their equivalent pore radius.

Erythrocytes↗

PubMed1989

Comparison of speed of sound and ultrasound attenuation in the os calcis to bone density of the radius, femur and lumbar spine.

Broadband ultrasonic attenuation (BUA) between 0.1 and 0.6 MHz and speed of sound (SOS) were measured on the os calcis in normal women (n = 40), and women who had mild osteoporosis (n = 36). Comparisons were made between the ultrasonic properties and bone mineral densities (BMD) obtained using photon absorptiometry on the lumbar spine, proximal femur and radius shaft. In the osteoporotic women, whose spine BMD was significantly reduced, BUA and SOS were lower, to about the same degree of significance as radius BMD; ROC analysis demonstrated that for discrimination of spinal osteopenia, the area under the ROC curve was similar for radius BMD, SOS, and BUA. There was a modest correlation (r about 0.65) between either SOS or BUA on the os calcis and BMDs of the spine and radius. Correlations of the SOS and BUA with femoral neck BMD were lower (r about 0.4 to 0.5). The standard error of estimate for both spine and femoral neck BMD was too high (about 0.14 g cm-2) for os calcis measurements to be substituted clinically for densitometry at these fracture sites.

Absorptiometry, Photon↗

PubMed2004

Cancellous bone changes in the radius of patients with rheumatoid arthritis: a cross-sectional quantitative macroradiographic study.

OBJECTIVE: Fractal signature analysis (FSA), a computerized method of textural analysis, permits the separate measurement of changes in vertical and horizontal trabeculae based on the fractal dimension over a range of trabecular widths (fractal signature). We determined whether the FSA of high-definition macroradiographs (x5 magnification) quantified radiographic changes at sites of osteopenia and erosion formation in the rheumatoid arthritis (RA) hand. METHODS: Sixty-seven RA patients had macroradiographs of the left wrist and hand. The distal radius was scored and grouped from very mild (RA1) to moderate (RA4) disease. Macroradiographs were digitized and FSA of horizontal and vertical trabecular organization was performed in the radius at sites of periarticular osteopenia, erosion formation and at a mid-metaphyseal site. The RA groups were compared with 11 healthy non-arthritic subjects using ANOVA and Dunnett's tests. RESULTS: Compared to the non-arthritic hands, FSA at the distal radius in groups RA1 to RA4 measured significantly lower (P<0.05) fractal signatures. The fractal signatures were lowest in RA4 involving small, medium to large sized vertical trabeculae at the periarticular osteopenic (0.18 to 0.84 mm, P<0.01) and mid-metaphyseal sites (0.12 to 0.60 and 0.84 to 1.02 mm, P </= 0.04), and small to medium sized vertical trabeculae at the periarticular erosion site (0.24 to 0.84 mm, P<0.01). CONCLUSION: FSA quantified radiographic bone loss in the distal radius of RA patients with increasing radiographic severity in terms of lower fractal signatures compared with the non-arthritics. Disease-related bone loss was demonstrated by FSA to involve mainly vertical trabeculae at the periarticular osteopenic, periarticular erosion and the mid-metaphyseal sites indicating directionality of bone resorption in RA.

Arthritis, Rheumatoid↗

PubMed2000

Lower extremity deformities associated with thrombocytopenia and absent radius syndrome.

The cases of 11 patients with the syndrome of thrombocytopenia and absent radius (TAR syndrome) who presented at two institutions between 1970 and 1996 were reviewed. Knee deformities have been well documented in thrombocytopenia and absent radius syndrome, but an inordinate frequency of other lower extremity problems needing orthopaedic attention was seen. Five of the 11 patients with thrombocytopenia and absent radius syndrome studied had knee deformities, but seven of the 11 had 11 other lower extremity deformities. This article documents all of the lower extremity problems seen in the seven patients with thrombocytopenia and absent radius syndrome with anomalies other than those of the knee.

Child, Preschool↗

PubMed2001

Biomechanical efficacy of an internal fixator for treatment of distal radius fractures.

Despite the effectiveness of external fixation in the treatment of complex wrist fractures, the complication rate for this modality ranges from 20% to 62%. Common complications are related to the use of percutaneous metal pins and result in an average reoperation rate of 16%. In addition, external fixation is unable to prevent dorsal collapse of the radius or maintain the normal palmar tilt of the radiocarpal joint surface. This complication may predispose to posttraumatic wrist instability and arthritis. The problems with external fixation have prompted a search for a better treatment option. An internal fixator placed through limited incisions on the dorsal aspect of the radius and spanning the fracture site can, in theory, provide the benefits of external fixation without the associated morbidity. This study determined the biomechanical efficacy of internal fixators compared with external fixators using a standardized model for an unstable wrist fracture. Two commercially available metal plates were used as internal fixators. Biomechanical testing of the devices was done, and stiffness was determined. Results showed that the internal fixators were significantly stiffer than were the external fixators in axial loading. Failure in axial loading, specifically compression, is a consistent reason for loss of reduction in intraarticular distal radius fractures. The clinical implications of these results suggest that an internal fixator theoretically can prevent loss of reduction in the axial plane and maintain palmar tilt by acting as a rigid dorsal buttress. In addition, the use of an internal fixator potentially decreases the high morbidity associated with external fixation. Additional investigation into the clinical application of internal fixators for distal radius fractures is needed.

Biomechanical Phenomena↗

PubMed1996

Contact stress distributions in malreduced intraarticular distal radius fractures.

Residual articular incongruity of the distal radius following intraarticular fracture has been correlated with early osteoarthritis (OA) and a poor clinical outcome. We developed a simple in vitro fracture model of the distal radius to investigate the relationship between degree of articular incongruity and the resulting distribution of radiocarpal contact stress. Twelve fresh-frozen cadaver arms were dissected, packets of Fuji Pressensor film were inserted into the wrist, and the wrist was loaded through its flexor and extensor tendons. We created a simple intraarticular fracture that allowed controlled distal radius articular incongruity. Loading trials were performed for the intact distal radius, for a fully reduced case, and for step-offs of 0.4, 1, 2, and 3 mm. Mean contact stress was significantly greater than the anatomically reduced case at only 3 mm of step-off. Contact area was greater than the anatomically reduced case at 0.4, 1, and 2 mm of step-off. The elevations in contact stress that we observed were only modest, suggesting that other factors may be involved in the pathogenesis of radiocarpal OA in the presence of residual articular incongruity.

Adult↗

PubMed2002

Open reduction and internal fixation of unstable distal radius fractures: results using the trimed fixation system.

OBJECTIVE: The purpose of this study was to evaluate the early results of patients with displaced and unstable distal radius fractures treated with fragment-specific fixation. DESIGN Prospective and consecutive. SETTING: Private orthopaedic practice. PATIENTS/PARTICIPANTS: Twenty-five patients with 27 fractures with an average follow-up of 29 months (range 24-36 months) treated with fragment-specific fixation for unstable radius fractures. MAIN OUTCOME MEASUREMENTS: Clinical and radiographic examination. Disabilities of the arm, hand, and shoulder and patient-rated wrist evaluation outcome measures. RESULTS Patients had an average 61 degrees of dorsiflexion and 54 degrees of palmarflexion at the wrist. Twenty-five fractures healed in acceptable alignment, with one loss of reduction and one patient death. Mean +/- standard deviation DASH score was 17 +/- 18, and PRWE score was 19 +/- 22. CONCLUSION: Unstable distal radius fractures can be reliably and anatomically reduced and stabilized using fragment-specific fixation. Fixation of markedly comminuted fractures is secure enough to allow immediate motion and does not require casting or external fixation. Preliminary clinical and radiographic results are excellent, and patient satisfaction is high. Anatomic reduction with early motion can be achieved in a routine fashion on unstable distal radius fractures using the described technique.

Adult↗

PubMed1994

Mandibular reconstruction with osseointegrated implants into the free vascularized radius.

Complete oral rehabilitation after oromandibular resection is a goal that is frequently difficult to attain. Poor speech, inability to eat a solid diet, and cosmetic deformity are all potential problems. The introduction of osseointegrated implants and free vascularized bone grafting are two techniques that have permitted improved results of oromandibular reconstruction. When used together they provide the best possibility for providing oral continence, a stable denture, and minimal cosmetic deformity. The free vascularized iliac crest has been used widely to reconstruct mandibular defects with the placement of enosseus implants. However, the radius provides a good alternative to reconstruct the mandible. We report four cases of mandibular reconstruction with the use of the free vascularized radius with subsequent placement of osseointegrated implants. The results of these cases suggest that enosseus implants can be used successfully in the radius. The radius is ideal to reconstruct small to moderate-sized defects of the lateral mandible with loss of oral mucosa.

Adult↗

PubMed2006

Current concepts in volar fixed-angle fixation of unstable distal radius fractures.

UNLABELLED: We present new developments in the volar treatment of unstable distal radius fractures in adults. New perspectives on the anatomy of the wrist, the watershed line on the volar radius and the usefulness of the pronator fossa are presented and these help to avoid flexor and extensor tendon disturbance when using a volar approach. Other new insights on the bony anatomy of the distal end of the radius are discussed, which are important in improving the quality of fracture fixation, including the benefits of constructing a precise fixed-angle scaffold underneath the articular surface in order to stabilize it. A volar fixed-angle plate must support the dorsal, central and volar aspects of the subchondral bone in order to stabilize the most complex fractures. Awareness of the anatomy of blood supply to the distal radius: the dorsal retinaculum that feeds the distal fragments and the blood supply to the diaphysis through branches of the anterior interosseous artery is necessary to maximize healing potential and avoid complications. Volar fixed-angle plates need to withstand very high forces during rehabilitation, the magnitude of these forces are up to five times the loads applied on the hand. LEVEL OF EVIDENCE: Level V (expert opinion).

Biomechanical Phenomena↗

PubMed2006

Corrective osteotomies in malunions of the distal radius: do we get what we planned?

UNLABELLED: Fifteen patients with symptomatic malunions of the distal radius were treated with osteotomies, corticocancellous bone grafting, and plate and screw fixation. We investigated the ability of precise preoperative planning of the size and shape of the corticocancellous bone graft to restore alignment of the radius to within 5 degrees angular deformity and 2 mm ulnar variance as compared with the opposite uninjured wrist. Only six of 15 patients (40%) satisfied these criteria. Inter-rater reliability of radiographic assessment was greater than 0.85. Five patients had residual radial inclination or sagittal tilt greater than 10 degrees with respect to the uninvolved wrist. Four patients had a residual ulnar variance greater than 2 mm with respect to the uninvolved wrist. Residual shortening (three of four patients), but not residual angulation, was associated with unsatisfactory pain and stiffness an average of 19.5 months after osteotomy (range, 11-32 months). We conclude that a distal radius osteotomy using a precisely planned and measured interpositional corticocancellous graft does not restore distal radius alignment in most patients, and that failure to restore length is associated with continued pain and stiffness. LEVEL OF EVIDENCE: Therapeutic study, Level IV (case series).

Adolescent↗

PubMed2006

Two potential causes of EPL rupture after distal radius volar plate fixation.

Rupture of the extensor pollicis longus tendon can occur after volar plate fixation of dorsally comminuted distal radius fractures. We attempted to identify the etiology of extensor pollicis longus tendon injury after volar plate fixation of the distal radius and potential solutions to this problem. After describing two case reports, we examine six cadaveric specimens and retrospectively review 10 selected patients to evaluate possible technique refinements to minimize damage to the extensor pollicis longus tendon during volar plating of the distal radius. We identify specific screw holes in three commercially available volar distal radius plates that direct the drill bit or prominent screw tips into the third extensor compartment. In addition, after reduction and plate fixation, bone fragments or dorsal gapping may predispose the extensor pollicis longus tendon to injury. We recommend either using shorter screw lengths or leaving the implicated plate holes unfilled. In addition, we suggest consideration of an open assessment of the third extensor compartment, if indicated, as performed through a small dorsal incision ulnar to Lister's tubercle.

Adult↗

PubMed1999

Effect of age, exercise and growth rate on bone mineral density (BMD) in third carpal bone and distal radius of Dutch Warmblood foals with osteochondrosis.

This study aimed a the determining bone mineral density (BMD) in the 3rd carpal bone and distal radius of foals age 5 and 11 months that had been subjected to different exercise regimens from birth until age 5 months. It was hypothesised that BMD would be greater in older animals, and that differences in exercise regimens before age 5 months would be associated with differences in BMD at both age 5 and 11 months. Epiphyseal bone tissue was available from 5 and 11 month old Warmblood foals bred from sires known to have radiographic evidence of osteochondrosis (OC). The foals were in a clinical trial which assessed the effect of exercise up to age 5 months on osteochondrosis (OC). Until age 5 months, foals were either box confined, box confined and sprint trained daily, or kept at pasture. Half the horses in each group were then confined together in a large stall, with access to pasture for 2 h daily, from age 6 to 11 months. BMD was assessed by dual x-ray absorptiometry in 4 areas of interest (AOIs) of excised third carpal bone (C3) and 5 in the distal radius. Volumetric BMD was determined in C3, only surface BMD was analysed in the radius. Across age groups, exercise had an effect on BMD in the mediodorsal and mediopalmar areas of C3. In the 5-month-old animals, the training exercise had similar effect to constant pasture exercise. In all AOIs, BMD was significantly greater in 11-month than in 5-month-old animals. Between age groups there was a difference in effect of exercise regimen before 5 months, in mediodorsal C3 and medial aspect of the radius, and the difference observed between exercise groups at age 5 months was no longer present in horses age 11 months, indicating no residual effect of early exercise. BMD was lower in the group with high OC scores. In the group of horses with the most severe OC, monthly growth rate did not fall uniformly with age over the first 5 months, as it did in groups with lower OC scores. It was concluded that exercise influenced significantly BMD at 5 months, suggesting that carefully designed training programmes to increase bone mineral could be employed in young animals. There was no residual effect at 11 months.

Absorptiometry, Photon↗

PubMed2005

Clinical application of double dorsal plates for the distal radius fractures.

The purpose of this study was to develop plates that fit the contour of the distal radius of the Japanese and can be inserted less invasively. Three-dimensional models of 36 radii of 18 volunteers were prepared. Using these models, the shape of the cortical bone on the radial margin of the distal radius and just below the dorsal fourth compartment of the wrist, to which the plates were expected to be applied, was measured, and the curves of the plates were determined. The functions of approximated curves of the plates were: [y = -2 x 10(-8) x5 - 2 x 10(-6) x(4) + 0.0006 x3 - 0.0312 x2 + 0.3274 x + 15.224 on the radial margin of the distal radius and [y = 7 x 10(-7) x5 - 0.0001 x4 + 0.0078 x3 - 0.2355 x2 + 3.1815 x - 5.6383 just below the fourth compartment. The clinical results of the application of double dorsal plates were satisfactory in clinical cases for the distal radius fractures.

Adult↗

PubMedDate not supplied

Early active rehabilitation for operatively stabilized distal radius fractures.

From the young to the elderly, distal radius fractures are very common. Extensive literature has been written regarding surgical management of distal radius fractures, but the same degree of attention has not been given to the critical rehabilitation that follows. Successful functional outcomes for distal radius fractures are a result of appropriate surgical treatment as well as timely and specific rehabilitation. Surgical treatment strategies available for unstable distal radius fractures include percutaneous pinning, external fixation, dorsal plating, and volar fixed-angle plating. Arthroscopically assisted as well as other minimally invasive techniques are now gaining acceptance. The ideal surgical treatment would provide stable fixed-angle fragment-specific support with minimal soft tissue disturbance and allow safe, early active wrist rehabilitation. This article reviews the normal anatomy of the region, the pathoanatomy created by the different stabilization strategies, and specific therapy techniques, including static and static progressive splints, that correlate with each of the surgical procedures.

Arthroscopy↗

PubMed2004

An in vitro study of the ultrasonic axial transmission technique at the radius: 1-MHz velocity measurements are sensitive to both mineralization and intracortical porosity.

UNLABELLED: The ultrasonic axial transmission technique allows for investigating skeletal sites such as the cortical layer of long bones (radius, tibia, phalanges). Using synchrotron radiation microCT, we investigated, in vitro, the relationships between 1-MHz axial transmission SOS measurements at the radius and site-matched measurements of C.Th, POR, MIN, and vBMD. INTRODUCTION: The ultrasonic axial transmission technique allows for investigating skeletal sites such as the cortical layer of long bones (radius, tibia, phalanges). MATERIALS AND METHODS: Using synchrotron radiation microCT, we investigated, in vitro, the relationships between 1-MHz axial transmission speed of sound (SOS) measurements at the radius and site-matched measurements of cortical thickness (C.Th), intracortical porosity (POR), tissue mineralization (MIN), and volumetric BMD (vBMD). SOS measurements were based on bidirectional axial transmission and were performed with a 1-MHz proprietary probe on 39 excised human radii. RESULTS: The highest correlations between SOS values and bone parameters (R(2)(SOS/POR) = 0.28, p < 10(-3); R(2)(SOS/MIN) = 0.38, p < 10(-4); R(2)(SOS/vBMD) = 0.57, p < 10(-3)) were found for bone parameters assessed in a 1-mm-thick periosteal region of the cortex rather than throughout the whole cortex. The observed moderate correlation between SOS and C.Th values (R(2)(SOS/C.Th) = 0.20, p < 10(-2)) disappeared when controlled for other variables. The two best multilinear predictive models, including either BMD alone or the pair of dependent variables MIN and POR (all assessed in the periosteal cortex), were equally accurate in predicting SOS values (R(2)(SOS/(POR,MIN)) = 0.59, p < 10(-5); R(2)(SOS/vBMD) = 0.57, p < 10(-5)). CONCLUSION: For the first time, the respective adjusted contributions of POR (-24 m/s%(-1)) and tissue mineralization (+3.5 m/s/mg/cm(-3)) to SOS values were assessed. These results suggest potential sensitivity of axial transmission SOS values to changes in cortical bone status under different pathological conditions or treatments affecting POR and/or tissue mineralization.

Aged↗

PubMed1999

Site-specific effects of strength training on bone structure and geometry of ultradistal radius in postmenopausal women.

Knowledge of the effects of exercise on bone mass in postmenopausal women is limited and controversial. Animal studies have shown that the response of bone to bending strain is an alteration of bone geometry. We studied 250 postmenopausal women, aged 52-72 years, willing to participate in a 6-month exercise program. The first 125 started the program immediately and the remaining 125 served as controls. The training program included exercises designed to maximize the stress on the wrist. One hundred and eighteen of the active group and 116 of the control group completed the study and were reassessed 6 months later. Bone mineral density (BMD) of the femoral neck, lumbar spine, ultradistal and proximal radius was measured by dual-energy X-ray absorptiometry (DXA) both before and at the end of the exercise program. The forearm was also evaluated by peripheral quantitative computed tomography, which measures the area, bone mineral content (BMC), and volumetric density for both the cortical and the trabecular component. The results showed that the DXA measurements at the femoral neck, lumbar spine, ultradistal and proximal radius were similar between the two groups. No significant difference was detected after the exercise program at the proximal radius. At the ultradistal radius, the cross-sectional area of cortical bone rose by 2.8 +/- 15.0% (SD, p < 0.05), apparently for both periosteal apposition and corticalization of the trabecular tissue. The volumetric density of cortical bone rose by 2. 2 +/- 15.8% (p < 0.1), and that of trabecular bone decreased by 2.6 +/- 10.7% (p < 0.01). The combined changes in both bone volume and density in the exercise group were associated with marked increase in cortical BMC (3.1 +/- 10.7%, p < 0.01) and decrease in trabecular BMC (-3.4 +/- 14.2%, p < 0.05), which were statistically different from those observed in the control group (p < 0.05). In conclusion, these results confirm that site-specific moderate physical exercises have very little effect on bone mass. However, it appears that some exercises may reshape the bone segment under stress by increasing both the cross-sectional area and the density of the cortical component. These structural changes are theoretically associated with increases in the bending strength.

Absorptiometry, Photon↗

PubMed2003

Hip fracture discrimination study: QUS of the radius and the calcaneum.

As an emerging alternative to current radiation-based bone densitometry techniques, there is a growing interest in the use of quantitative ultrasound (QUS) measurements for the noninvasive assessment of fracture risk in the management of osteoporosis. However, there are also a multiplicity of technologically different QUS devices available on the market and, so far, no study has compared heel and radius QUS device for the discrimination of subjects with hip fractures. Our study evaluated the ability of three QUS devices (one calcaneal gel-coupled system, one calcaneal water-coupled system, and one radius system) to discriminate osteoporotic from controls subjects, using the same population. We also checked if the combination of two different skeletal sites (i.e., calcaneum and radius) improve the discriminatory ability of the QUS devices. Forty-five women aged 79.1+/-7.1 yr with hip fractures within the last 4 d were used as the hip-fracture group and compared to 40 healthy controls from 65-87 yr. In addition, 47 young controls, aged 20-40 yr, were used as reference population to express some of the results as T-scores. QUS measurements were performed with the Hologic Sahara, Ge-Lunar Achilles+, and Sunlight Omnisense devices according to the manufacturer's recommendations. Adjusted odds ratio results showed that a decrease in Omnisense SOS of 1 standard deviation (SD) was associated with a significant increase in fracture risk (OR adj.=2.83) comparable with Sahara BUA (OR adj.=2.42) and Achilles BUA (OR adj.=3.29). However, given the large overlap between the 95% intervals of each odds ratio, no significant difference was found between the devices. Similarly, comparison between the areas under ROC curves did not show any significant difference between all the parameters. Considering the parameters provided per default by each QUS device, the Sahara, Achilles, and Omnisense devices classified correctly 70, 67.5, and 62.5% of the subjects, respectively. Although the OR of the combination of radius and calcaneum is improved (3.62 to 4.74) compared with either one of the single skeletal site, the large confidence intervals do not allow to claim a significant difference. The three QUS technologies tested against hip fractures seem to show the same discriminatory ability. However, there is some differences in the definition of the diagnostic threshold underlying the nonusability of the World Health Organization (WHO) osteoporosis definition. Finally the combination of several site using two different devices is not clinically relevant. Potential interest could be seen in combining several sites using the same device, supposing that such device would measure differently active bone.

Aged↗