Alteration in hypoplasia of the hindfoot structures during early growth in clubfeet treated using the Ponseti method.

PURPOSE: Previous reports have demonstrated diminished size of the hindfoot bones in patients with idiopathic clubfoot deformity. However, no study has quantified the percentage of hypoplasia as a function of early growth, during the brace phase of Ponseti treatment. METHODS: We measured the dimensions of ossified structures on radiographs in patients with unilateral Ponseti-treated clubfeet to determine changes in the percentage of hypoplasia between two and four years of age. RESULTS: The degree of hypoplasia varied among the osseous structures in Ponseti-treated clubfeet at age two years, with greater hypoplasia being observed in the talus (7.3%), followed by calcaneus (4.9%) and the cuboid (4.8%). Overall, the degree of hypoplasia diminished by four years, such that the degree of hypoplasia was greatest in the talus (4.2%) and the calcaneus (4.2%) followed by the cuboid (0.6%). At four years of age, the greatest degree of hypoplasia persisted in the talus and calcaneus. CONCLUSIONS: Changes occurred in the size of the ossification of hindfoot bones between two and four years of age, and the observed changes in the percentage of hypoplasia varied among the different structures. At four years of age, the greatest percentage of hypoplasia was observed in the talus and calcaneus at values similar to those previously reported in skeletally mature patients. The results suggested that the relative difference in size of the feet may be expected to remain constant in a child with a unilateral clubfoot after this age.

Quantification of the ossification of the lateral cuneiform in the feet of young children with unilateral congenital talipes equinovarus.

AIMS: After the initial correction of congenital talipes equinovarus (CTEV) using the Ponseti method, a subsequent dynamic deformity is often managed by transfer of the tendon of tibialis anterior (TATT) to the lateral cuneiform. Many surgeons believe the lateral cuneiform should be ossified before surgery is undertaken. This study quantifies the ossification process of the lateral cuneiform in children with CTEV between one and three years of age. PATIENTS AND METHODS: The length, width and height of the lateral cuneiform were measured in 43 consecutive patients with unilateral CTEV who had been treated using the Ponseti method. Measurements were taken by two independent observers on standardised anteroposterior and lateral radiographs of both feet taken at one, two and three years of age. RESULTS: All dimensions of the lateral cuneiform on the affected side increased annually but remained smaller than the corresponding dimensions of the unaffected foot (p < 0.01). The lateral cuneiform resembled a 9 mm cube at two years and an 11 mm cube at three years. CONCLUSION: At one and two years, the ossification centre of the lateral cuneiform may not be large enough to accommodate a drill hole for tendon transfer. However, by three years, it has undergone sufficient ossification to do so. Cite this article: Bone Joint J 2017;99-B:1109-14.

How do different anterior tibial tendon transfer techniques influence forefoot and hindfoot motion?

BACKGROUND: Idiopathic clubfoot correction is commonly performed using the Ponseti method and is widely reported to provide reliable results. However, a relapsed deformity may occur and often is treated in children older than 2.5 years with repeat casting, followed by an anterior tibial tendon transfer. Several techniques have been described, including a whole tendon transfer using a two-incision technique or a three-incision technique, and a split transfer, but little is known regarding the biomechanical effects of these transfers on forefoot and hindfoot motion. QUESTIONS/PURPOSE: We used a cadaveric foot model to test the effects of three tibialis anterior tendon transfer techniques on forefoot positioning and production of hindfoot valgus. METHODS: Ten fresh-frozen cadaveric lower legs were used. We applied 150 N tension to the anterior tibial tendon, causing the ankle to dorsiflex. Three-dimensional motions of the first metatarsal, calcaneus, and talus relative to the tibia were measured in intact specimens, and then repeated after each of the three surgical techniques. RESULTS: Under maximum dorsiflexion, the intact specimens showed 6° (95% CI, 2.2°-9.4°) forefoot supination and less than 3° (95% CI, 0.4°-5.3°) hindfoot valgus motion. All three transfers provided increased forefoot pronation and hindfoot valgus motion compared with intact specimens: the three-incision whole transfer provided 38° (95% CI, 33°-43°; p < 0.01) forefoot pronation and 10° (95% CI, 8.5°-12°; p < 0.01) hindfoot valgus; the split transfer, 28° (95% CI, 24°-32°; p < 0.01) pronation, 9° (95% CI, 7.5°-11°; p < 0.01) valgus; and the two-incision transfer, 25° (95% CI, 20°-31°; p < 0.01) pronation, 6° (95% CI, 4.2°-7.8°; p < 0.01) valgus. CONCLUSION: All three techniques may be useful and deliver varying degrees of increased forefoot pronation, with the three-incision whole transfer providing the most forefoot pronation. Changes in hindfoot motion were small. CLINICAL RELEVANCE: Our study results show that the amount of forefoot pronation varied for different transfer methods. Supple dynamic forefoot supination may be treated with a whole transfer using a two-incision technique to avoid overcorrection, while a three-incision technique or a split transfer may be useful for more resistant feet. Confirmation of these findings awaits further clinical trials.

First measurement of the ionization yield of nuclear recoils in liquid argon.

This Letter details a measurement of the ionization yield (Q(y)) of 6.7 keV(40)Ar atoms stopping in a liquid argon detector. The Q(y) of 3.6-6.3 detected e(-)/keV, for applied electric fields in the range 240-2130 V/cm, is encouraging for the use of this detector medium to search for the signals from hypothetical dark matter particle interactions and from coherent elastic neutrino-nucleus scattering. A significant dependence of Q(y) on the applied electric field is observed and explained in the context of ion recombination.

Simulation of extreme loads on the proximal femur for implant fixation assessment.

Total joint replacement patients today are younger, heavier, and more active than total joint replacement patients 40 yrs ago. Consequently, patient expectations and prosthesis requirements have increased and there is a need to re-evaluate preclinical testing methods. We present the design rationale for a novel load simulator for the proximal femur, capable of applying a more aggressive load profile than previous simulators. This simulator was used to measure three-dimensional micromotion of a cemented total hip replacement femoral stem under simulated physiological loading. We assessed the influence of a separate abductor muscle force, a higher joint reaction force, and a more accurate implant stability measurement system included in the new simulator and compared the results to the lower, single joint reaction force included in a previously published simulator. Per-cycle motion at both cement interfaces and stem and cement mantle migration obtained from both simulators using the same femoral stem design, are compared. Although the new simulator applied higher loads, per-cycle motions were lower than previously reported. In both studies, regardless of the presence or lack of a separate muscle force, the greatest motions were in the medial-lateral direction (new: 27 +/- 4 mum, old: 67 +/- 21 mum). The findings indicate that magnitude and direction of peak joint reaction force and inclusion of a separate muscle force have a significant effect on femoral stem stability measurements. We recommend that future femoral stem stability studies consider using load simulation techniques and a direct motion measurement system comparable to the one presented in this study.

New limit on the neutrinoless betabeta decay of 130Te.

We report the present results of CUORICINO, a search for neutrinoless double-beta (0nu betabeta) decay of 130Te. The detector is an array of 62 TeO2 bolometers with a total active mass of 40.7 kg. The array is cooled by a dilution refrigerator shielded from environmental radioactivity and energetic neutrons, operated at approximately 8 mK in the Gran Sasso Underground Laboratory. No evidence for (0nu betabeta) decay was found and a new lower limit, T(1/2)(0nu) > or = 1.8 x 10(24) yr (90% C.L.) is set, corresponding to [m(nu)] < or = 0.2 to 1.1 eV, depending on the theoretical nuclear matrix elements used in the analysis.

Effects of total hip arthroplasty cemented femoral stem surface finish, collar and cement thickness on load transfer to the femur.

Stress shielding and load transfer to the femur following total hip arthroplasty have been studied extensively. A number of models have addressed the effects of surface finish of double-tapered, non-collared cemented stems on load transfer to the femur. However, a great number of cemented femoral stem designs in wide use today are not double tapered, and many, such as the Charnley, have collars. The effects of surface finish of such stems on load transfer to the femur are not completely understood. In this study, we measured the effects of surface finish of a straight, non-tapered cemented femoral stem, with and without a collar, in two stem sizes, on load transfer to the femur, using an in vitro laboratory model. Eight types of straight stems were fabricated, with polished or rough surfaces, with and without a collar, and in two sizes. All stems were based on the same template, and varied only in the desired combination of parameters studied. Three each of the eight unique stem types (total of 24 specimens) were cyclically loaded for 77,000 cycles at 1 Hz, alternating between walking and stair-climbing load profiles. Surface strains were measured at ten locations in each femur during designated initial and final periods. Of the three design variables, stem surface finish had the greatest effect on femoral surface strains. Specifically, compared to rough stems, with polished stems, mean proximal medial compressive strains were smaller, whereas mean distal medial compressive strains were greater. In contrast, on the anterior surface, mean proximal anterior tensile strains were greater, whereas mean distal anterior strains were smaller. All femoral surface strains increased with cyclic loading, however, strains increased at a greater rate with polished stems than with rough stems. Proximal medial strains were somewhat increased with the presence of a collar, however, these differences were small (< 100 microå ) and/or not statistically significant. Similarly, distal medial strains were increased with the presence of a collar but, again, the differences were not consistent (p > 0.16). Compared to large stems, with small stems, proximal medial compressive strains were greater. The results emphasize the importance cemented femoral stem surface roughness and the manner in which this changes stem-cement bond strength, affecting the distribution of stresses in the femur. This is an important consideration in the design of femoral stems. (Journal of Applied Biomaterials & Biomechanics 2003; 1: 76-83).

[Late ventricular potentials in the post-infarct patient. A follow-up at 4 years]. / I potenziali tardivi ventricolari nel post-infarto. Follow-up a 4 anni.

We performed a prospective study to evaluate the prognostic significance and the natural history of late ventricular potentials (LPs) in 209 patients (165 males and 44 females; mean age 59.8 +/- 10 years) who survived acute myocardial infarction. Signal-averaged electrocardiograms (SA-ECGs) were performed before hospital discharge (16 +/- 5 days) and after four years (mean follow-up 42 +/- 7 months). SA-ECGs were processed using a 40 Hz high-pass bidirectional filter. Duration of "filtered" QRS (normal value < 120 msec), duration of the low-amplitude signals (n.v. < 39 msec) and last 40 msec voltage of the QRS complex (n.v. > 20 microV) were measured. LPs were defined as the presence of two or more abnormal values. In addition, 24-hour Holter monitoring was performed in all patients, and left ventricular ejection fraction (LVEF) was determined by scintigraphy in 120 (57.4%). Sixty patients (28.7%) had LPs before hospital discharge (group 1), and 149 (71.3%) had normal SA-ECGs (group 2). During the follow-up period there were 10 arrhythmic events, 7 of which were sudden deaths, and three cases of sustained ventricular tachycardia. SA-ECG was repeated in 141 patients (68%). The mean values of SA-ECG's parameters did not change significantly between the two controls, and the correlation was good for all of them. Despite this, spontaneous normalization of SA-ECGs occurred in 21 patients (60%) and the subsequent appearance of LPs was seen in 13 (12%); in these latter, the SA-ECG's parameters measured before hospital discharge were "borderline" and significantly different from those who did not change. The sensitivity of SA-ECG as a predictor of arrhythmic events was 80% and the specificity 74%. Patients with arrhythmic events had a longer filtered QRS (126 +/- 33 vs 103 +/- 12 msec; p < 0.001), longer duration of the low-amplitude signals (57 +/- 23 vs 32 +/- 11 msec; p < 0.001), lower voltages (17 +/- 8 vs 36 +/- 24 microV; p < 0.001), and, moreover, higher peak CK values, lower LVEF and higher value of Lown modified class. In conclusion, SA-ECG confirms its value in identifying patients at risk of arrhythmic events after myocardial infarction. SA-ECG recordings taken before the discharge can be used to predict serial changes during follow-up.

Prognostic significance and evolution of late ventricular potentials in the first year after myocardial infarction: a prospective study.

We performed a prospective study of the high-frequency components of the terminal portion of the QRS complex in 220 patients who survived acute myocardial infarction. Signal-averaged electrocardiograms (SA-ECGs) were performed before hospital discharge (16 +/- 6 days) and then serially at regular intervals over the following year. SA-ECGs were processed using a 40 Hz high-pass bidirectional filter. Duration of "filtered" QRS (D-normal value less than 120 ms), duration of the low-amplitude signals (D40 - n.v. less than 39 ms) and last 40 ms voltage of the QRS complex (V40 - n.v. greater than 20 microV) were measured. Late potentials (LPs) were defined as the presence of two or more abnormal values. In addition, 24-hour Holter monitoring was performed in 208 patients and left ventricular ejection fraction (LVEF) was determined by scintigraphy in 111. Sixty-two patients (group 1) had LPs, 158 had normal SA-ECGs (group 2). Spontaneous normalization of SA-ECGs occurred in 20% of patients after 6 months, although the mean values of D, D40 and V40 did not change significantly and the reproducibility was very good for all the indexes during all the follow-up controls. Three patients had sudden death and three presented again with spontaneous, sustained ventricular tachycardia. Five of 62 (8%) group 1 patients had an arrhythmic event compared with one of 158 patients (0.6%) in group 2. The sensitivity of SA-ECGs as a predictor of arrhythmic events was 83% with a specificity of 73%. Patients with subsequent arrhythmic events had longer filtered QRS (133 +/- 19 vs 104 +/- 16 ms; P less than 0.001), longer duration of the low-amplitude signals (54 +/- 15 vs 33 +/- 14 ms; P less than 0.01), and lower voltages in the last 40 ms of the filtered QRS (11 +/- 3 vs 36 +/- 25 microV; P less than 0.02) and, moreover, higher peak CK values and lower LVEF than those without such events. In conclusion, SA-ECGs provide important prognostic information in identifying patients at risk of arrhythmic events after myocardial infarction although dynamic changes of LPs are observed during the first year after myocardial infarction.

Ventricular and supraventricular arrhythmias in clinically silent right ventricular infarction.

To study the relationship between clinically silent right ventricular infarction and the incidence of a-v block, atrial and ventricular arrhythmias, 100 patients with inferior wall myocardial infarction underwent equilibrium gated radioisotopic angiocardiography. Fifty-four of them had radioisotopic evidence of right ventricular involvement and 43 (80%) of them had a-v block and/or supraventricular arrhythmias during the acute phase of the infarct, while only 10 (22%) of the 46 patients without right ventricular involvement did. As regards the incidence of ventricular tachyarrhythmias, 14 (26%) patients with right ventricular involvement had ventricular tachycardia and/or fibrillation, while only one patient without right ventricular involvement had ventricular tachycardia, and no patients had ventricular fibrillation. Moreover, V4R-precordial lead showed a sensitivity in predicting the risk of developing a-v block/supraventricular arrhythmias and ventricular tachyarrhythmias of 0.84 and 0.79, respectively. Therefore, right ventricular involvement should be suspected when atrial arrhythmias, a-v block and ventricular tachyarrhythmias are found in early acute inferior wall myocardial infarction. On the other hand, when right precordial lead V4R in early acute inferior infarction shows ST-elevation and/or a QS pattern, the sudden occurrence of these arrhythmias should be suspected, and possibly prevented.

[Vascular changes in postmastectomy "thick arm"]. / Studio delle modificazioni vascolari nel "braccio grosso" postmastectomia.

The authors, after shortly outlining some pathogenetic theories about postmastectomy "big arm", especially dwell upon the theory of the hindered venous discharge. They, subsequently, through a clear and interesting phlebographic iconography, illustrate ten of the 41 cases suffering from such syndrome, they recently had the opportunity to observe. On the basis of their own experience, and according to part of the literature thereabout, the authors think very probably the postmastectomy "big arm" is to be ascribed to the hindered venous reflux of upper limb (for thrombosis or compression), due to the operation of mastectomy. As a conclusion, they suggest the improvement or recovery of this syndrome by stepping over the stenosed venous tract through a by-pass.