Immunogenicity of a Live-Attenuated Dengue Vaccine Using a Heterologous Prime-Boost Strategy in a Phase 1 Randomized Clinical Trial.

BACKGROUND: Dengue is a global health problem and the development of a tetravalent dengue vaccine with durable protection is a high priority. A heterologous prime-boost strategy has the advantage of eliciting immune responses through different mechanisms and therefore may be superior to homologous prime-boost strategies for generating durable tetravalent immunity. METHODS: In this phase 1 first-in-human heterologous prime-boost study, 80 volunteers were assigned to 4 groups and received a tetravalent dengue virus (DENV-1-4) purified inactivated vaccine (TDENV-PIV) with alum adjuvant and a tetravalent dengue virus (DENV-1-4) live attenuated vaccine (TDENV-LAV) in different orders and dosing schedules (28 or 180 days apart). RESULTS: All vaccination regimens had acceptable safety profiles and there were no vaccine-related serious adverse events. TDEN-PIV followed by TDEN-LAV induced higher neutralizing antibody titers and a higher rate of tetravalent seroconversions compared to TDEN-LAV followed by TDEN-PIV. Both TDEN-PIV followed by TDEN-LAV groups demonstrated 100% tetravalent seroconversion 28 days following the booster dose, which was maintained for most of these subjects through the day 180 measurement. CONCLUSIONS: A heterologous prime-boost vaccination strategy for dengue merits additional evaluation for safety, immunogenicity, and potential for clinical benefit. CLINICAL TRIALS REGISTRATION: NCT02239614.

A Phase 1, Open-Label Assessment of a Dengue Virus-1 Live Virus Human Challenge Strain.

BACKGROUND: Dengue human infection models (DHIM) have been used as a safe means to test the viability of prophylaxis and therapeutics. METHODS: A phase 1 study of 12 healthy adult volunteers using a challenge virus, DENV-1-LVHC strain 45AZ5, was performed. A dose escalating design was used to determine the safety and performance profile of the challenge virus. Subjects were evaluated extensively until 28 days and then out to 6 months. RESULTS: Twelve subjects received the challenge virus: 6 with 0.5 mL of 6.5 × 103 plaque-forming units (PFU)/mL (low-dose group) and 6 with 0.5 mL of 6.5 × 104 PFU/mL (mid-dose group). All except 1 in the low-dose group developed detectable viremia. For all subjects the mean incubation period was 5.9 days (range 5-9 days) and mean time of viremia was 6.8 days (range 3-9 days). Mean peak for all subjects was 1.6 × 107 genome equivalents (GE)/mL (range 4.6 × 103 to 5 × 107 GE/mL). There were no serious adverse events or long-term safety signals noted. CONCLUSIONS: We conclude that DENV-1-LVHC was well-tolerated, resulted in an uncomplicated dengue illness, and may be a suitable DHIM for therapeutic and prophylactic product testing. CLINICAL TRIALS REGISTRATION: NCT02372175.

Multicountry prospective clinical evaluation of two enzyme-linked immunosorbent assays and two rapid diagnostic tests for diagnosing dengue fever.

We evaluated four dengue diagnostic devices from Alere, including the SD Bioline Dengue Duo (nonstructural [NS] 1 Ag and IgG/IgM), the Panbio Dengue Duo Cassette (IgM/IgG) rapid diagnostic tests (RDTs), and the Panbio dengue IgM and IgG capture enzyme-linked immunosorbent assays (ELISAs) in a prospective, controlled, multicenter study in Peru, Venezuela, Cambodia, and the United States, using samples from 1,021 febrile individuals. Archived, well-characterized samples from an additional 135 febrile individuals from Thailand were also used. Reference testing was performed on all samples using an algorithm involving virus isolation, in-house IgM and IgG capture ELISAs, and plaque reduction neutralization tests (PRNT) to determine the infection status of the individual. The primary endpoints were the clinical sensitivities and specificities of these devices. The SD Bioline Dengue Duo had an overall sensitivity of 87.3% (95% confidence interval [CI], 84.1 to 90.2%) and specificity of 86.8% (95% CI, 83.9 to 89.3%) during the first 14 days post-symptom onset (p.s.o.). The Panbio Dengue Duo Cassette demonstrated a sensitivity of 92.1% (87.8 to 95.2%) and specificity of 62.2% (54.5 to 69.5%) during days 4 to 14 p.s.o. The Panbio IgM capture ELISA had a sensitivity of 87.6% (82.7 to 91.4%) and specificity of 88.1% (82.2 to 92.6%) during days 4 to 14 p.s.o. Finally, the Panbio IgG capture ELISA had a sensitivity of 69.6% (62.1 to 76.4%) and a specificity of 88.4% (82.6 to 92.8%) during days 4 to 14 p.s.o. for identification of secondary dengue infections. This multicountry prospective study resulted in reliable real-world performance data that will facilitate data-driven laboratory test choices for managing patient care during dengue outbreaks.

Tunnel convergence in combined anterior cruciate ligament and posterolateral corner reconstruction.

PURPOSE: To examine the geometric relationship between tunnels created in the lateral femoral condyle in reconstruction of the anterior cruciate ligament (ACL) and the posterolateral structures. METHODS: The geometric relationship between a standard ACL tunnel and 11 lateral femoral tunnel variations in synthetic femur specimens was examined. Tunnel collision frequency and tunnel separation were measured radiographically. Subsequent evaluation was performed on 7 paired cadaveric specimens (14 knees) to access the efficacy of 2 configurations. RESULTS: Phase I-Tunnel collision frequency was 0% and 58% for 25-mm and 30-mm tunnel depths, respectively. Axial angles greater than 40 degrees and coronal angles > or =20 degrees resulted in unsafe configurations. The safest position for lateral tunnel placement was straight lateral approach (0 degrees in the coronal plane) with increased axial plane orientation (hand dropped toward the floor 40 degrees). The safe zone for lateral tunnel configuration was determined to be between [0,0] and [0,40] ([coronal, axial]). Phase II--Control group ([0,0]) collision frequencies were 43% and 86% for the 25-mm 30-mm tunnels, respectively. Experimental group ([0,40]) collision frequencies were 29% and 43% for the 25-mm and 30-mm tunnel, respectively. In femoral condyles measuring <35 mm, collision rates were 100% versus 0% in the control group ([0,0]) versus the experimental group ([0,40]). In specimens where no collision was seen, tunnel separation distance was 4.5 +/- 4.4 mm and 5.8 +/- 2.2 mm for the control and experimental groups, respectively (P = .39). CONCLUSIONS: Tunnel collision occurred often. Tunnel collision is dependent on femoral condyle geometry, tunnel depth, and tunnel configuration. To minimize the potential for tunnel collision, the surgeon should maintain a neutral alignment in the coronal plane, limit lateral tunnel depth to < or =25 mm, and direct the lateral tunnel anteriorly in the axial plane to a maximum of 40 degrees. CLINICAL RELEVANCE: This study describes guidelines for tunnel placement to prevent tunnel collision when performing combined ACL and posterolateral corner reconstruction.

Assessing the Dengue Diagnosis Capability Gap in the Military Health System.

Dengue, one of the most widespread infectious diseases, has affected U.S. military readiness throughout history. We explored the dengue diagnosis capability gap by circulating a questionnaire among military end users to determine in what capacity diagnostic test results are needed and how these results would be used at various roles of care in the Military Health System. Results were used to generate target product profiles for potential diagnostic tests. We determined that at far-forward locations, diagnostic tests need to be rugged and easy to use and are primarily needed to inform medical evacuation decisions. In mobile or fixed hospitals, diagnostics can be less portable but must be accurate enough to inform patient care decisions reliably. We then evaluated the suitability of using rapid diagnostic tests and enzyme-linked immunosorbent assays based on published performance characteristics, and we used a model to determine positive and negative predictive values in certain simulated deployments. In far-forward settings, a rapid diagnostic test comprising both antigen- and antibody-based detection can fulfill the capability gap with reasonable accuracy, whereas at higher roles of care immunoglobulin M-enzyme-linked immunosorbent assay was determined to be the most suitable option.

Interference Kirschner wires augment distal humeral fracture fixation in the elderly.

OBJECTIVES: This study was designed to compare the biomechanical stability of a two-plate distal humerus fixation with and without Kirschner-wire (K-wire) augmentation of supracondylar osteotomies. DESIGN: Ex vivo paired cadaveric study. SETTING: Biomechanical laboratory. MATERIALS: : Five pairs of fresh, elderly cadaveric humeri. INTERVENTION: Two 3.5-mm reconstruction plates were used to stabilize each humerus. This fixation model was selected solely to evaluate the effect of K-wire augmentation. Augmentation consisted of 2 K-wires placed in both the medial and lateral columns of the humerus to interdigitate with the plate screws. A posteriorly directed load was cyclically applied to the distal fragment for 5000 cycles or until failure, and osteotomy site motion was tracked optically. MAIN OUTCOME MEASUREMENTS: Fixation survival was defined as 5000 cycles or the number of cycles until osteotomy site motion reached >2 mm. RESULTS: K-wire augmented fixations survived significantly more cycles than did controls (4410 +/- 875 vs. 1114 +/- 2182, respectively; paired t test, P < 0.05). CONCLUSIONS: Augmentation with K-wires may decrease the incidence of loss of fixation in distal humeral fractures.

Ex vivo biomechanical comparison of hydroxyapatite and polymethylmethacrylate cements for use with vertebroplasty.

BACKGROUND AND PURPOSE: Little is known about the mechanical stabilization afforded by new materials proposed for use with vertebroplasty. This comparative ex vivo biomechanical study was designed to determine the strength and stiffness of osteoporotic vertebral bodies (VBs) subjected to compression fractures and stabilized with bipedicular injections of Cranioplastic altered in a manner consistent with the practice of vertebroplasty or BoneSource cement. METHODS: VBs T8-T10 and L2-L4 from 10 fresh spines were harvested from female cadavers (aged 91.5 years +/- 3.9 at death). These were screened for bone density (t score, -4.9 +/- 1.4; bone mineral density, 0.61 g/cm(2) +/- 0.19), disarticulated, and compressed to determine initial strength and stiffness. The fractured VBs were stabilized with bipedicular injections of a predetermined quantity and type of cement and then re-crushed. RESULTS: At both the thoracic and lumbar levels, VBs repaired with altered Cranioplastic resulted in significantly greater strength (P <.05) than that in their prefracture states, whereas those repaired with BoneSource were restored to their initial strength. Cranioplastic resulted in significantly stronger repairs than BoneSource in the thoracic region; however, repair strengths in the lumbar region were not significantly different. The repaired stiffness was significantly lower than the initial stiffness in all treatments and in both regions. Differences in the repaired stiffness between the treatment groups in either region and differences in the mechanical parameters obtained by adding an additional 2 mL of BoneSource were not significant. CONCLUSION: Both materials in the volumes used either restored or increased VB strength, but none restored stiffness.

A biomechanical evaluation of transcondylar femoral fixation of anterior cruciate ligament grafts.

BACKGROUND: Interference screw fixation of the graft in anterior cruciate ligament reconstruction is considered the gold standard, but limited clinical experience suggests that transcondylar fixation is equally effective. PURPOSE: To compare transcondylar and interference screw fixation. STUDY DESIGN: Ex vivo biomechanical study. METHODS: Twenty pairs of unembalmed knees underwent anterior cruciate ligament reconstruction with patellar tendon autografts. In 1 knee of each pair, the bone plug was stabilized in the femoral tunnel with standard interference screws; in the other knee, transcondylar screws were used. Testing to failure occurred immediately or after 1000 cycles of sinusoidal loading (30 to 150 N) (20 paired reconstructions each). Fixation stiffness, strength, graft creep, displacement amplitude, and change in amplitude were measured and compared (repeated measures anaylsis of variance with Tukey test; P <.05). RESULTS: There was no significant difference in acute strength, maximum load within 3 mm, or stiffness between transcondylar fixation (410 +/- 164 N, 183 +/- 93 N, and 49.6 +/- 28 N/mm, respectively) and interference fixation (497 +/- 216 N, 206 +/- 115 N, and 61 +/- 37.8 N/mm, respectively). Similarly, there was no significant difference in cyclic strength, maximum load within 3 mm, or stiffness between transcondylar fixation (496 +/- 214 N, 357 +/- 82.9 N, and 110 +/- 27.4 N/mm, respectively) and interference fixation (552 +/- 233 N, 357 +/- 76.2 N, and 112 +/- 26.8 N/mm, respectively). Predominant modes of failure were bone plug pullout (transcondylar fixation) and tendon failure or bone plug fracture (interference fixation). CONCLUSIONS: Transcondylar screw fixation of the patellar tendon autograft into the femoral tunnel performed mechanically as well as interference screw fixation. CLINICAL RELEVANCE: The results suggest that transcondylar and interference screws provide similar fixation for anterior cruciate ligament reconstruction.

Biomechanical evaluation of intramedullary nail versus tension band fixation for transverse olecranon fractures.

OBJECTIVES: To compare the biomechanical stability of an alternative custom-designed intramedullary nail (IMN) fixation with that of traditional tension band wiring (TBW), the gold standard for stabilizing transverse olecranon fractures. DESIGN: Ex vivo biomechanical study. SETTING: Biomechanical laboratory. MATERIALS: Six pairs of elderly cadaver elbows. INTERVENTION: A simulated transverse olecranon fracture was created in each elbow after it had been denuded of most of its soft tissue. The right and left olecranons of each pair were alternately assigned to the IMN or TBW group. A tensile force was applied via the triceps tendon while the elbow was secured in 90 degree of flexion. MAIN OUTCOME MEASUREMENTS: Displacement at the simulated fracture segment was measured optically. Fixation failure was defined as >2 mm of fracture displacement. The differences in stiffness and maximum load to failure between the two treatments were analyzed for significance (P < 0.05) using a one-tailed paired t test. RESULTS: IMN fixation was significantly stiffer and stronger than TBW fixation. CONCLUSIONS: The locked IMN provided stronger and stiffer fixation than did TBW. Theoretically the IMN fixation would require less surgical exposure and would be expected to require fewer revisions than TBW fixation. IMN fixation warrants consideration as a clinical alternative to TBW.

The effect of oblique femoral tunnel placement on rotational constraint of the knee reconstructed using patellar tendon autografts.

PURPOSE: Despite the high long-term success rates of anterior cruciate ligament (ACL) reconstructions, 8% of patients undergoing this primary procedure have recurrent disability and graft failure. Nonanatomic tunnel positioning (primarily of the femoral tunnel) accounts for most of all technical failures. We hypothesized that reconstructions that closely recreate the oblique femoral attachment of the ACL would result in more normal knee rotational stability than more vertical reconstruction. The purpose of this study was to determine whether obliquity of the femoral tunnel in the coronal (frontal) plane has an effect on rotational constraint after ACL reconstruction, as measured by anterior tibial translation, external rotation, and internal rotation. TYPE OF STUDY: Ex vivo biomechanical study. METHODS: Ten matched pairs of fresh-frozen cadaver knees were alternately assigned to a standard or an oblique tunnel position reconstruction. Each knee was tested at 30 degrees and 90 degrees of flexion on a materials testing machine in ACL-intact, ACL-sectioned, and ACL-reconstructed states. A 100-N load was applied at a rate of 10 N/second, and anterior tibial translation was measured. Then 6.5 Nm of torque were applied, and external tibial rotation and internal tibial rotation were measured. The effects of tunnel placement and ligament condition were analyzed with a repeated measures analysis of variance. Significance was set at P < or =.05 (Tukey's test). RESULTS: At 30 degrees of flexion, internal tibial rotation in oblique reconstruction was restored to intact values and was significantly less than the internal tibial rotation values in standard reconstruction. Internal tibial rotation in standard reconstruction was significantly greater than intact values. No significant differences were found between standard and oblique tunnel reconstructions and the respective intact values for the remaining internal tibial rotation and all external tibial rotation tests, regardless of flexion angle. CONCLUSIONS: In our biomechanical model, ACL reconstructions using oblique femoral tunnels restored normal knee kinematics.

A biomechanical evaluation of clinical stress tests for syndesmotic ankle instability.

Displacement transducers were placed across the anterior and posterior tibiofibular ligaments of 17 fresh cadaver (78.4 +/- 6.7 years old at death) lower extremities. Displacements induced by various clinical tests (squeeze, fibula translation, Cotton, external rotation, and anterior drawer) were measured with the ankle ligaments intact and after sequential sectioning of the anterior tibiofibular ligament, anterior deltoid ligament, and posterior tibiofibular ligament. None of the syndesmotic stress tests could distinguish which ligaments were sectioned. Furthermore, the small displacements measured during the stress tests (with the exception of the external rotation test) suggest it is unlikely that the displacement induced in injured syndesmoses can be clinically differentiated from normal syndesmoses. Therefore, pain, rather than increased displacement, should be considered the outcome measure of these tests.

Fifth metatarsal tuberosity fracture fixation: a biomechanical study.

This study tested the hypothesis that fixation of a fifth metatarsal tuberosity fracture with a lag screw that engages the intact medial cortex is biomechanically stronger than fixation with a long intramedullary screw (control). The right and left feet from 10 male cadavers were alternately assigned to the two fixation groups. After fracture reduction and fixation, each specimen was potted in acrylic cement and tested on a servohydraulic testing machine. The repairs were then distracted until failure by placing the peroneus brevis tendon under tension at a rate of 1 mm/s. The lag screw technique resulted in a significantly greater mean (+/- SD) load to failure (150 +/- 90 N) than did intramedullary screw fixation (70 +/- 60 N) (p < .05) and may offer a useful method of internal fixation of fifth metatarsal tuberosity fractures when surgical stabilization is indicated.

A biomechanical evaluation of the tibiofibular and tibiotalar ligaments of the ankle.

The purpose of this ex vivo biomechanical study was to determine the strength and stiffness of the anterior and posterior syndesmotic tibiofibular ligaments and the posterior tibiotalar component of the deltoid ligament. Injuries to these ligaments are a prevalent clinical problem, yet little is known about their mechanical behavior. Ten fresh-frozen cadaver lower extremities (average age at death, 72 +/- 8 years) were harvested. The anterior and posterior tibiofibular ligaments and the posterior tibiotalar component of the deltoid were isolated and prepared as bone-ligament-bone complexes for tensile testing to determine strength, stiffness, and mode of failure. The posterior tibiofibular ligament exhibited greater strength, but not significantly so (p < .05), than the anterior tibiofibular ligament and the posterior tibiotalar component of the deltoid ligament. There were no significant differences in stiffness between the three ligaments tested. The dominant mode of failure for the anterior tibiofibular ligament was ligament substance rupture, primarily near its fibular insertion, whereas the failure modes of the posterior tibiofibular ligament were evenly split between substance ruptures and fibular avulsions. The posterior tibiotalar component of the deltoid ligament ruptured most often near the talar insertion. The tibiofibular ligaments showed greater strength than the lateral collateral and deltoid ligaments, as mentioned in literature. The greater strength of the tibiofibular ligaments relative to the lateral collateral and deltoid ligaments suggests that these ligaments play an important role in ankle constraint.

Biomechanical comparison of two fixation methods for first metatarsophalangeal joint arthrodesis.

PURPOSE: The aim of this study was to compare the mechanical stability of two methods of fixation for arthrodesis of the hallux metatarsophalangeal joint: 1. a technique using an intramedullary screw and 2. a standard technique using crossed interfragmentary compression screws. METHODOLOGY: The metatarsophalangeal joint was mechanically evaluated in cantilever bending using a servohydraulic testing machine. Differences in stiffness and strength parameters between the two techniques were checked for significance (P<0.05) using a paired t-test. RESULTS: Fixation provided by the intramedullary screw was stiffer and stronger than that from crossed compression screws. CONCLUSIONS: The stronger and stiffer intramedullary screw technique offers mechanical advantages over the crossed interfragmentary screw technique.

The effect of the monomer-to-powder ratio on the material properties of acrylic bone cement.

The procedure percutaneous vertebroplasty consists of injecting polymethylmethacrylate cement into vertebral bodies for the treatment of osteoporotic compression fractures and tumors of the spine. Clinicians practicing vertebroplasty commonly alter the mixture of monomer-to-powder recommended by the manufacturer in an effort to decrease viscosity and increase the working time. The purpose of the current study was to measure the effect of varying the monomer-to-powder ratio on the compressive material properties (compressive modulus, yield stress, and ultimate compressive strength) of the cement Simplex P (Stryker-Howmedica-Osteonics, Rutherford, NJ). Cylindrical specimens were prepared using monomer-to-powder ratios of 0.45 to 1.00 mL/g and tested in compression. Peak compressive material properties occurred at the mixture ratio recommended by the manufacturer (0.5 mL/g) but decreased as the ratio of monomer to powder was increased. The material properties of specimens cured for 1 hour were significantly less than those for specimens cured for 24 hours. The monomer-to-powder ratio affects the compressive material properties of cement. The clinical significance of these results with respect to vertebroplasty is yet to be determined.

An ex vivo evaluation of an inflatable bone tamp used to reduce fractures within vertebral bodies under load.

STUDY DESIGN: Ex vivo biomechanical study using osteoporotic cadaveric vertebral bodies. OBJECTIVE: To determine if fracture reduction could be achieved by the inflatable bone tamp (tamp) in vertebral bodies under simulated physiologic loads. SUMMARY OF BACKGROUND DATA: Previous ex vivo biomechanical studies showed that kyphoplasty restored vertebral body height with vertebral body endplates under stress-free conditions. METHODS: Simulated compression fractures were experimentally created in 18 osteoporotic vertebral bodies alternatingly assigned to one of two treatment (tamp inflation) groups: low axial load (111 N) or high axial load (222 N). Each vertebral body was then placed between two platens in a special radiolucent loading fixture and subjected to the preassigned load to simulate in vivo physiologic loading. The tamps were inflated and postreduction heights were measured fluoroscopically. The effect of applied load and condition on vertebral body height was checked for significance (P < 0.05). RESULTS: Comparing the experimental conditions (initial, postcompression, postinflation), there were no significant vertebral body height differences between the load groups (low load vs. high load). However, vertebral body height differences between conditions within each load group were all significant. For the low-load and high-load groups, mean postinflation heights (24.4 and 24.4 mm) were significantly greater than mean postcompression heights (21.6 and 22.5 mm) but significantly less than initial vertebral body heights (26.6 and 26.3 mm), respectively. Initial heights were fully restored in 22% (two of nine) of vertebral bodies in both groups. CONCLUSION: The inflatable bone tamp restored some of the height lost to compression fractures in vertebral bodies under simulated physiologic loads.

Biomechanical comparison of kyphoplasty with different bone cements.

STUDY DESIGN: Ex vivo biomechanical study. OBJECTIVES: To compare the biomechanical properties of isolated, fractured, osteoporotic vertebral bodies after treatment by kyphoplasty with one of two cements: alpha-tri-calcium phosphate cement (Biopex-R; Mitsubishi Materials Corp., Tokyo, Japan) or polymethylmethacrylate (Simplex P; Stryker-Howmedica-Osteonics, Mahwah, NJ). SUMMARY OF BACKGROUND DATA: Kyphoplasty and vertebroplasty typically use polymethylmethacrylate cements for the treatment of osteoporotic compression fractures. Scant information exists regarding the use of alternative cements in kyphoplasty. METHODS: Simulated compression fractures were created in 24 vertebral bodies (T6-T9, L2-L5) harvested from three female cadavers. Vertebral bodies were assigned to one of two groups: kyphoplasty with Biopex-R or kyphoplasty with Simplex P. The kyphoplasty treatment consisted of inserting bone tamps bipedicularly into each vertebral body, inflating the tamp, and filling the created void with Biopex-R or Simplex P. Pretreatment and post-treatment heights were measured, and the repaired vertebral bodies were recompressed to determine posttreatment strength and stiffness values. Differences were checked for significance (P < 0.05) using a repeated-measures analysis of variance followed by Tukey's test. RESULTS: Kyphoplasty with Biopex-R restored strength in the lumbar and thoracic vertebral bodies. Kyphoplasty with Simplex P displayed significantly greater posttreatment strength than initial strength in the thoracic region. Vertebral bodies augmented with either cement were significantly less stiff than their initial conditions, except for the thoracic vertebrae treated with Simplex P, in which stiffness was restored. There was no significant difference in percentage of height restored between the cement treatments. CONCLUSIONS: Kyphoplasty with either cement restored initial strength. In general, stiffness was not restored.

A biomechanical evaluation of lateral plating of distal radial shaft fractures.

PURPOSE: In this ex vivo biomechanical study we compared the maximum anterior/posterior bending moment, maximum torque, torsional stiffness, and twist angle at failure of distal radial shaft (Galeazzi) fractures stabilized with lateral plating (LP) and anterior plating (AP) and subjected to 4-point anterior/posterior bending and torsion. METHODS: Simulated fractures (oblique osteotomy between the middle and distal thirds of each radius) were created in 21 pairs of fresh, unembalmed, cadaver radii. One radius from each pair was stabilized with AP (n = 21); the contralateral radius was stabilized with LP (n = 21). Eleven pairs of specimens were tested to failure in torsion; the remaining 10 pairs were tested to failure in 4-point anterior/posterior bending. Differences between plating groups were checked for significance using paired t-tests. RESULTS: AP fixation was stronger in torsion (12.8 +/- 5.6 N-m) and anterior/posterior bending (40.1 +/- 25.7 N-m) than LP fixation (10.7 +/- 5.6 N-m and 36.0 +/- 30.5 N-m, respectively), although the differences were not significant. Similarly there was no significant difference in twist angle at failure (29 degrees +/- 13 degrees vs 23 degrees +/- 10 degrees ) or in torsional stiffness (0.6 +/- 0.2 N-m/ degrees vs 0. 6 +/- 0.2 N-m/ degrees ) between AP and LP fixations, respectively. CONCLUSIONS: Because LP fixation was not mechanically superior to AP fixation and required additional tendon elevation and dissection of the dorsal sensory nerve and possibly of the lateral antebrachial cutaneous nerves, AP fixation appears to be the preferable treatment for Galeazzi fractures.