Inclination Measurements Research Articles

Investigation on the Inclination of Cathode Plasma Jets in High-Current Vacuum Arcs in Magnetic Field

The theoretical and experimental studies of cathode plasma jets in vacuum arc and the effect of magnetic field on them have been under way for several years. In this paper, different axial magnetic field electrodes were tested in a vacuum chamber, obvious individual cathode plasma jets were observed, and the cathode-jet inclination was also detected. Based on the numerical calculation of magnetic field in interelectrode region and the measurement of cathode-jet inclination in experimental results, it is proven that the inclination angle of composite magnetic field (the combination of the axial, the azimuthal, and the radial components) is consistent with the inclination angle of cathode plasma jets, which indicates that the cathode plasma jets in the arc column flow along the magnetic-field direction when the high-current vacuum arc is diffused or even constricted slightly. Meanwhile, it was also found that plasma jets far from the cathode surface mixed with each other and became ambiguous when the electrode gap increases to a certain distance.

Rotational deformity affects radiographic measurements in distal radius malunion

Malunited distal radius fractures are 3D deformities. The preoperative evaluation of the deformity and surgical planning are usually depended on plain radiographic measurements for corrective osteotomies. In most of the cases, the rotational deformity is disregarded in preoperative planning. We aimed to clarify the effect of rotational deformity on radial inclination and dorsal or volar tilt measurements, which are commonly used as radiologic parameters. This study was performed on standard left radius saw bone models. The malunion models were prepared according to AO distal radius fracture classification system in four main and seventeen subgroups. The differences between the mean radial inclination, volar or dorsal tilt measurements performed on plain radiographies and gold standard values were statistically analyzed. Results showed that rotational deformity causes faulty measurements of radial inclination and dorsal tilt on plain radiographies which may be a contributing factor for unsatisfactory clinical results of corrective osteotomy. We suggest 3D preoperative evaluation of the deformity if possible.

Electron beams as the source of whistler‐mode auroral hiss at Saturn

Over the last three years, the Cassini spacecraft has been in a series of high inclination orbits, allowing investigation and measurements of Saturnian auroral phenomena. During this time, the Radio and Plasma Wave Science (RPWS) Investigation on Cassini detected low frequency whistler mode emissions propagating upward along the auroral field lines, much like terrestrial auroral hiss. Comparisons of RPWS data with Cassini Plasma Spectrometer (CAPS) plasma measurements during a high‐latitude pass on 17 October 2008, show that intense upward moving electron beams with energies of a few hundred eV were associated with auroral hiss emissions. In this paper we show that these beams produce large growth rates for whistler‐mode waves propagating along the resonance cone, similar to the generation of auroral hiss at Earth.

Occurrence of retrograde and reoriented migration during formation of the pontine nucleus

Glenoid retroversion may accelerate glenoid loosening after total shoulder arthroplasty. Accurate measurement of preoperative glenoid deformity is critical for decision-making and prognostication. The purpose of this study was to determine whether glenoid version, inclination, and depth and humeral subluxation measurements on computed tomography (CT) scan slices oriented in the plane of the body differ from those oriented in the scapular plane and those obtained by automated 3-dimensional reconstruction software in the setting of a biconcave B2-type glenoid.Thirty-one preoperative CT scans in patients undergoing total shoulder arthroplasty with Walch B2-type glenoids underwent a standardized measurement protocol by 3 observers. Glenoid version, inclination, and depth and humeral subluxation were measured on 2-dimensional CT images in the plane of the body, on 2-dimensional images in the plane of the scapula, and by a validated, automated 3-dimensional software program.Correction of CT slice axis into the plane of the scapula decreased measured retroversion by 2.4° to 4.7° (P < .004) and inclination by 21° (P < .001). Whereas uncorrected version measurements do not differ from automated software measurements, corrected measurements do (P < .001). Whereas corrected inclination measurements do not differ from automated measurements, uncorrected measurements do (P < .001). Automated measurements differed from both corrected and uncorrected subluxation (P < .001 in both cases).If CT images are not reoriented into the plane of the scapula, version and inclination will be significantly overestimated. In the setting of a retroverted, deformed glenoid, automated software may produce similar inclination measurements to corrected 2-dimensional CT, but it produces significantly altered measurements of version and subluxation.

Leaf wettability decreases along an extreme altitudinal gradient

The duration and amount of water captured on leaves and its functional significance is highly varied. Leaf surface wettability influences water absorption, gas exchange, pathogen infection, nutrient leaching, contamination by pollutants, self-cleaning properties and in freezing environments the probability of extrinsic ice nucleation. To test the impact of environment on the development of leaf wettability, this functional trait was measured in 227 dominant plant species along an extreme altitudinal environment gradient (186-5,268 m) on the wet and dry slopes of the Nepalese Himalayas. Plants from the understorey and open places in woodlands were also compared. Leaf wettability was assessed by droplet contact angle (theta), retention and leaf inclination measurement. With increasing altitude leaf wettability decreased significantly parallel to the observed atmospheric temperature decrease (0.5 K/100 m). Leaves from non-freezing tropical and subtropical origins were highly wettable (theta < 90 degrees). Temperate leaves were non-wettable (110 degrees < theta < 130 degrees). Subalpine and alpine leaves were highly non-wettable (130 degrees < theta < 150 degrees) and adaxial pubescence occurred more frequently. Leaves taken from the understorey were more wettable but had a better droplet run off than leaves sampled in open places. In the semi-arid northern slopes (temperate to alpine) of the Himalayas leaf wettability was decreased in comparison to the southern humid side. The majority of the leaves had a low droplet retention <20 degrees ; higher values were linked to high non-wettability (theta > 130 degrees) which was more often observed at high altitude. Good droplet run off at +/-10 degrees inclination was found in highly wettable leaves (theta < 90 degrees) of tropical and subtropical origin and on leaves from the forest understorey. Structural properties for low wettability are developed in cold and dry environments and open sites with frequent dew formation as it appears to be an important functional trait to prevent a number of the negative effects adhering surface water may have.

Optimal inertial sensor location for ambulatory measurement of trunk inclination

Trunk inclination (TI) is used often to quantify back loading in ergonomic workplace evaluation. The aim of the present study was to determine whether TI can be obtained using a single inertial sensor (IS) on the back, and to determine the optimal IS location on the back for the estimation of TI. Gold standard TI, the angle between the vertical and the line connecting the L5/S1 joint and the trunk centre of mass, was measured using an optoelectronic system. Ten subjects performed experimental trials, each consisting of a symmetric and an asymmetric lifting task, and of a left–right lateral flexion movement. Trials were repeated and, in between trials, the IS was shifted in small steps from a location on the thorax towards a location on the sacrum. Optimal IS location was defined as the IS location with minimum root-mean-square (RMS) error between the gold standard TI and the IS TI. Averaged over subjects, the optimal IS location for symmetric and asymmetric lifting was at about 25% of the distance from the midpoint between the posterior superior iliac spines (MPSIS) to the C7 spinous process. The RMS error at this location, averaged over subjects, was 4.6±2.9°. For the left–right lateral flexion task, the optimal IS location was at about 30% of the MPSIS to C7 distance. Because in most activities of daily living, pure lateral flexion does not occur often, it is recommended place the IS at 25% of the distance from the MPSIS to C7.

Fractures of the Distal Radius Treated With Cross-Pin Fixation and a Nonbridging External Fixator, the CPX System: A Preliminary Report

To present the preliminary findings of distal radius fractures (DRF) treated with percutaneous cross-pin fixation and a nonbridging external fixator, the Cross-Pin Fixation (CPX) system. Thirty-five consecutive patients with 37 DRFs were selected from a series of 51 DRFs for closed reduction, percutaneous pinning, and external fixation with the CPX system. Outcome was determined by studying (1) radiological measurements of radial height, palmar tilt, radial inclination and ulnar variance (UV); (2) grip and pinch strength; (3) wrist active range of motion; and (4) patient outcome instruments-the Patient-Rated Wrist Hand Evaluation and the Disabilities of the Arm, Shoulder, and Hand. We are reporting on 21 patients, 13 females and 8 males, mean age 54 years (range, 27 to 87 y) with AO type fractures A2, B2, B3, C1, C2, and C3. Follow-up was a minimum of 1 year (range, 12 to 36 months). Wrist rehabilitation began at a mean of 10 days (range, 4 to 16 d) after surgery. There was no loss of reduction. Final mean grip and lateral pinch strength recovered 86% and 94%, respectively, and active range of motion increased to a minimum of 89% of the noninjured side. Disabilities of the Arm, Shoulder, and Hand showed change in functional status (minimal detectable change at 95% confidence level) at 4 and 12 weeks. The Patient-Rated Wrist Hand Evaluation results reported resumption of usual activities in the early postoperative period. One patient developed type I complex regional pain syndrome, which resolved, and one patient had residual transient mild superficial radial nerve sensitivity. There were no pin track infections, nonunions, or tendon injuries. All patients returned to their prior employment and activities. The CPX system is a minimally invasive technique of closed reduction and internal fixation for displaced, reducible extra-articular and nondisplaced and displaced reducible intra-articular fractures of the distal radius, allowing rehabilitation of the wrist and resumption of usual activities while maintaining fracture reduction. Therapeutic IV.

DR21 MAIN: A COLLAPSING CLOUD

The molecular cloud, DR21 Main, is an example of a large-scale gravitational collapse about an axis near the plane of the sky where the collapse is free of major disturbances due to rotation or other effects. Using flux maps, polarimetric maps, and measurements of the field inclination by comparing the line widths of ion and neutral species, we estimate the temperature, mass, magnetic field, and the turbulent kinetic, mean magnetic, and gravitational potential energies, and present a 3D model of the cloud and magnetic field.

Improving LWD Image and Formation Evaluation by Using Dynamically Corrected Drilling-Derived LWD Depth and Continuous Inclination and Azimuth Measurements

Summary The paper illustrates the improvements in logging while drilling (LWD) images and subsequent formation evaluation by using a new methodology for depth and survey measurements corrections. LWD depth measurements are often considered inaccurate and, therefore, not as reliable for well-to-well correlations, correlations with data acquired with wireline measurements and formation layer thickness determinations. The reasons for these inaccuracies generally originate from the traditional practice that LWD depth is purposely made equal to the driller's depth, which is a static pipe length measurement made by tape at the surface. There is almost always a difference between the actual measured depth (MD) of the LWD sensor downhole and this static pipe measurement, because downhole the drillpipe is subject to an environment that is not representative of the derrick (e.g., varying drilling mechanical conditions and temperature changes). Here, we demonstrate the applications of the method, which allows dynamic driller's depth correction for the effects of drillstring weight, downhole friction, weight on bit, thermal expansion, residual rig heave, and tide. Another significant inaccuracy source is a standard practice of calculating borehole position from stationary survey points typically taken every 90 feet (ft) using the minimum curvature method. Neglecting the complex borehole shape between survey stations can lead to a systematic error in determining the borehole position. We consider using continuous inclination and azimuth measurements along with stationary surveys to correct these errors. We provide comparisons of LWD images before and after the depth and survey corrections to illustrate how the measurement errors affect formation dips interpreted from the images. We demonstrate how improved accuracy allows filtering out the artifacts and provides more decisive and accurate identification of geologic features. We show how using the corrected 3D position improves accuracy of the formation thicknesses calculations and therefore improves the reservoir summation results. As a result, we propose a borehole 3D position measurement that is accurate, consistent between wells (regardless of rig type or bottomhole assembly [BHA] configuration), and independent of the drilling mode. Using this new measurement significantly improves the quality of the formation evaluation.

Radiographic Outcome of Unstable Distal Radial Fracture Treated by Closed Reduction and Pin in Plaster

Background There is controversy about the appropriate treatment for severely displaced and unstable comminuted fracture of distal radius (type C of AO or OTA classification). Recently, there has been an increase in the number of predilection for surgical management of this fracture. Aim To determine the radiographic outcome in type C fractures of the distal radius treated with closed reduction and pin in plaster. Materials and Methods Eighty consecutive patients 60 male and 20 female, average age 40 years (22–60 years), with type C fractures of the distal radius seen between February 2001 and July 2003 in Shahid Kamiab Hospital of Mashad University, were treated by closed reduction and pin in plaster, followed up by anteroposterior and lateral radiographs to evaluate radial height, inclination and volar tilt. Results There was significant improvement in the measurements of radial height, inclination and volar tilt after closed reduction and pin in plaster, and at the time the pins and plaster were removed. (P = 0.00). Conclusion Closed reduction and pin in plaster is an effective, simple and low cost method in type C fractures of distal radius with satisfactory outcome.

Misalignment of the microquasar V4641 Sgr (SAX J1819.3–2525)

Abstract In the microquasar V4641 Sgr, the spin of the black hole is thought to be misaligned with the binary orbital axis. The accretion disc aligns with the black hole spin by the Lense-Thirring effect near to the black hole and further out becomes aligned with the binary orbital axis. The inclination of the radio jets and the Fe Kα line profile have both been used to determine the inclination of the inner accretion disc but the measurements are inconsistent. Using a steady-state analytical-warped disc model for V4641 Sgr, we find that the inner disc region is flat and aligned with the black hole up to about 900Rg. Thus, if both the radio jet and fluorescent emission originate in the same inner region then the measurements of the inner disc inclination should be the same.

Imaging and Navigation Measurement of Acetabular Component Position in THA

There are six different definitions of acetabular position based on observed inclination and anteversion made in either the (1) anterior pelvic plane or (2) coronal planes and based on whether each of the observations made in one of these two planes is (1) anatomic, (2) operative, or (3) radiographic. Anteroposterior pelvic tilt is the angle between the anterior pelvic plane and the coronal plane of the body. The coronal plane is a functional plane and the anterior pelvic plane is an anatomic pelvic plane. A cup may be in the "safe zone" by one definition but may be out of the "safe zone" by another definition. We reviewed published studies, analyzed the difference in varying definitions, evaluated the influence of the anterior pelvic tilt, and provided methods to convert from one definition to another. We recommend all inclination and anteversion measurements be converted to the radiographic inclination and anteversion based on the coronal plane, which is equivalent to the inclination and anteversion on the anteroposterior pelvic radiograph.

Is there a relationship between anterior knee pain and femoral trochlear dysplasia? Assessment of lateral trochlear inclination by magnetic resonance imaging

It may be very difficult to diagnose the pathology in patients with anterior knee pain. Patients with chronic anterior knee pain have been reviewed for the study. Our aim was to delineate the presence of subtle trochlear dysplasia by measuring lateral trochlear inclination (LTI) in axial magnetic resonance imaging (MRI) scans. While there were 109 knees in the study group with anterior knee pain (AKP), control group consisted of 74 knees without AKP. The LTI measurements were performed at the level of proximal cartilaginous area of trochlear groove in axial scans. The condition was termed to be trochlear dysplasia when LTI was below 11 masculine. Parameters in both groups were statistically analyzed and compared for their association with LTI. There was no significant difference between LTI values of male and female subjects in each group. The mean LTI values in anterior knee pain and control groups were 17.32 masculine and 21.5 masculine, respectively, and the difference was statistically significant (P < 0.05). The ratio of knees with trochlear dysplasia was 16.5% in AKP group, which was only 2.7% in control. In the AKP group, the ratio of trochlear dysplasia was significantly high (P < 0.05). Although trochlear dysplasia has been generally detected in cases with patellar instability, this study revealed that the frequency of this finding in patients with other causes of anterior knee pain was also considerably high. Measurement of lateral trochlear inclination in axial MRI scans with radiologic assessment seems to be a valuable diagnostic criterion, especially in patients in whom etiology of anterior knee pain could not be identified.

Recent investigations of the 0–5 Ma geomagnetic field recorded by lava flows

We present a synthesis of 0–5 Ma paleomagnetic directional data collected from 17 different locations under the collaborative Time Averaged geomagnetic Field Initiative (TAFI). When combined with regional compilations from the northwest United States, the southwest United States, Japan, New Zealand, Hawaii, Mexico, South Pacific, and the Indian Ocean, a data set of over 2000 sites with high quality, stable polarity, and declination and inclination measurements is obtained. This is a more than sevenfold increase over similar quality data in the existing Paleosecular Variation of Recent Lavas (PSVRL) data set, and has greatly improved spatial sampling. The new data set spans 78°S to 53°N, and has sufficient temporal and spatial sampling to allow characterization of latitudinal variations in the time‐averaged field (TAF) and paleosecular variation (PSV) for the Brunhes and Matuyama chrons, and for the 0–5 Ma interval combined. The Brunhes and Matuyama chrons exhibit different TAF geometries, notably smaller departures from a geocentric axial dipole field during the Brunhes, consistent with higher dipole strength observed from paleointensity data. Geographical variations in PSV are also different for the Brunhes and Matuyama. Given the high quality of our data set, polarity asymmetries in PSV and the TAF cannot be attributed to viscous overprints, but suggest different underlying field behavior, perhaps related to the influence of long‐lived core‐mantle boundary conditions on core flow. PSV, as measured by dispersion of virtual geomagnetic poles, shows less latitudinal variation than predicted by current statistical PSV models, or by previous data sets. In particular, the Brunhes data reported here are compatible with a wide range of models, from those that predict constant dispersion as a function of latitude to those that predict an increase in dispersion with latitude. Discriminating among such models could be helped by increased numbers of low‐latitude data and new high northern latitude sites. Tests with other data sets, and with simulations, indicate that some of the latitudinal signature previously observed in VGP dispersion can be attributed to the inclusion of low‐quality, insufficiently cleaned data with too few samples per site. Our Matuyama data show a stronger dependence of dispersion on latitude than the Brunhes data. The TAF is examined using the variation of inclination anomaly with latitude. Best fit two‐parameter models have axial quadrupole contributions of 2–4% of the axial dipole term, and axial octupole contributions of 1–5%. Approximately 2% of the octupole signature is likely the result of bias incurred by averaging unit vectors.

Clinical Evaluation of Semi-Adjustable Articulators: Reproducibility of Sagittal Condylar Path Inclination Assessed by a Jaw-Tracking System with Six Degrees of Freedom

To validate whether the data for individual patients are correctly reproduced in sagittal condylar path inclination of the articulator, the data obtained by the conventional anterior check bite method and the data obtained by a jaw-tracking system with six degrees of freedom were compared. In 5 subjects (4 males and 1 female) with healthy tooth alignments, 5 anterior check bites were obtained from each subject. Sagittal condylar path inclination was measured using seven types of semi-adjustable articulator. Next, the anterior gliding movement was measured 5 times in all 5 subjects using a jaw-tracking system with six degrees of freedom (MMJI- E, Shofu Inc. Kyoto, Japan. The sagittal condylar path inclination data obtained with semi-adjustable articulators were compared to those obtained by the jaw-tracking system using the two-way analysis of variance and Fisher's PLSD method (alpha = 0.05). In measurements of the same subjects for five types of articulators with the check bite method, significant differences were observed by two-way analysis of variance, and differences in measurements among articulators were found (p < 0.01). Regarding the sagittal condylar path inclinations measured with Hanau-184 Wide-View and Dentatus ARL articulators, significant differences were observed on both right and left sides compared with the jaw-tracking system. With the Denar Centri-Check System and Denar Mark II, significant differences were observed on one side (p < 0.05). Denar Cadiax Compact, Hanau Condyle Repositioner, and Hanau H2O are recommended for more accurate measurements of the sagittal condylar path inclination.

Correcting distorted paleosecular variation in late glacial lacustrine clay

An undisturbed, horizontal chronostratigraphic marker horizon of laminated red glacio-lacustrine clay crops out over ∼25,000 km 2 in northern Ontario, Canada. The primary, clastic hematite laminae possess two stable vector components of magnetization. We sampled a 1.6 m vertical section at overlapping 2 cm intervals in cubic specimens (8 cm 3, n = 106), precisely oriented in geographic coordinates which permitted measurement of inclination and declination. Alternating field demagnetization (12–17 steps per specimen) isolated a characteristic (ChRM), primary component (coercivity ≥40 mT) approximately 30° shallower than the mean geomagnetic field inclination at this latitude, with distorted paleosecular secular variation (PSV). A lower coercivity overprint (20–40 mT) is 6° shallower than the present geomagnetic field and similarly inclined to the depositional-remanence deflection when the clay was re-sedimented in the laboratory. We believe this angle to be representative of the inclination of the deflected primary remanence inclination during deposition, caused by the magnetic anisotropy of the clay. Using this as a proxy for the initial inclination, the ChRM (hard-component) inclinations were restored to their original values assuming vertical compaction, which averages to 51%. The restored inclinations are compatible with site-latitude and the restored secular-variation loops centre reasonably on the geographic North Pole. The structural correction based on homogeneous vertical shortening over-simplifies the reality of heterogeneous particulate flow in which grain rotations depend on shape, size and packing and effectively combines influences of compaction and depositional settlement. Nevertheless, this correction makes the PSV data more useful and interpretable in terms of paleopole migration. The more logical correction technique using anisotropy of anhysteretic remanence (AARM; Jackson, M.J., Banerjee, S.K., Marvin, J.A., Lu, R., Gruber, W., 1991. Detrital remanence, inclination errors, and anhysteretic remanence anisotropy: quantitative model and experimental results. Geophys. J. Int. 104: 95–103) is foiled here due to the high-coercivity of the remanence-bearing grains and their unknown orientation-distribution and shape-distribution.

A novel elastomer-based magnetoresistive accelerometer

In this paper, we present a novel type of biaxial accelerometer based on a polydimethylsiloxane (PDMS) structure as the mass–spring system and using magnetoresistive (MR) sensors as the detection method. The proof mass of the sensor is a mushroom-shaped polymer magnet made of PDMS filled with permanent magnet powder, whose minute movement under lateral acceleration is precisely sensed by a set of MR sensors. The device aims at consumer electronics applications of low g range and low frequency, such as inclination measurements and motion sensing. An experimental device has been successfully fabricated which showed a linear transfer curve without significant hysteresis. A sensitivity of 0.32mV/(Vg) was obtained.

Hubble Space Telescope time-series photometry of the planetary transit of HD 189733: no moon, no rings, starspots

We monitored three transits of the giant gas planet around the nearby K dwarf HD 189733 with the ACS camera on the Hubble Space Telescope. The resulting very-high accuracy lightcurve (signal-to-noise ratio near 15 000 on individual measurements, 35 000 on 10-min averages) allows a direct geometric measurement of the orbital inclination, radius ratio and scale of the system: i = 85.68 ± 0.04, Rpl/R∗ = 0.1572 ± 0.0004, a/R∗ = 8.92 ± 0.09. We derive improved values for the stellar and planetary radius, R∗ = 0.755 ± 0.011 R� ,Rpl = 1.154 ± 0.017 RJ, and the transit ephemerides, Ttr = 2453931.12048 ± 0.00002+n·2.218581 ± 0.000002. The HST data also reveal clear evidence of the planet occulting spots on the surface of the star. At least one large spot complex (>80 000 km) is required to explain the observed flux residuals and their colour evolution. This feature is compatible in amplitude and phase with the variability observed simultaneously from the ground. No evidence for satellites or rings around HD 189733b is seen in the HST lightcurve. This allows us to exlude with a high probability the presence of Earth-sized moons and Saturn-type debris rings around this planet. The timing of the three transits sampled is stable to the level of a few seconds, excluding a massive second planet in outer 2:1 resonance.

An X-ray template assessment for distal radial fractures

BackgroundThe current method for radiological measurements on plain X-rays of distal radius fractures is unreliable. We examined the reproducibility of a new X-ray assessment technique—where the uninjured side is used as a template for the injured side—compared to the conventional assessment technique.MethodsX-rays of 30 patients with a unilateral distal radial fracture were included reflecting the prevalence of AO fracture types in clinical practice. Eight experienced observers assessed these X-rays on two separated occasions (2-month interval) using the traditional measurement technique and the template technique. Reproducibility of the X-ray assessments was quantified by intraclass correlations and weighted kappa coefficients.ResultsThe reproducibility of the radial length measurement did not improve nor did the volar angulation measurement. However, marked improvement in reproducibility was observed for the radial inclination measurement, the kappa increased from 0.36 (95 % CI; 0.30–0.41) to 0.49 (95 % CI; 0.43–0.55) in the template technique. As a result, the classification of the reduction results (Lidström score) greatly improved. The overall kappa for the Lidström score improved from 0.37 (95 % CI; 0.31/0.43) to 0.59 (0.52/0.63).ConclusionThe assessment technique using the uninjured side as a template for the injured side resulted only in an improved reproducibility of the radial inclination measurement which in turn resulted in an improved classification reproducibility of the reduction results.

Can carpal malalignment predict early and late instability in nonoperatively managed distal radius fractures?

The purpose of this study was to assess the frequency of carpal instability as a concomitant lesion in distal radius fractures and identify other factors including carpal malalignment in an attempt to predict the final radiological outcome more accurately following conservative treatment of distal radius fractures. An observational study from patient records and standardised radiological follow-up examinations as data sources was used. The alignment of each wrist was checked radiographically immediately post-reduction and subsequently at 1- and 6-week follow-up assessments. Serial measurements of radial length, dorsal tilt, radial inclination, scapho-lunate, radio-lunate, radioscaphoid, scapho-capitate angles and effective radiolunate flexion angle were made. Regression analysis showed high correlation among the severity of axial shortening, pre-reduction dorsal angulation and radio-carpal malalignment pattern with early loss of reduction at 1 week. We found the age, severity of axial radial shortening, dorsal angulation, presence of dorsal comminution and radio-carpal malalignment pattern to be significant predictors of adverse radiological outcome at 6 weeks (late instability). Our study highlights the importance of radio-carpal instability pattern on post-reduction radiographs as a predictor of early and late instability.