Validation of a noninvasive maturity estimate relative to skeletal age in youth football players.

OBJECTIVE: To validate a non-invasive measure of biological maturity (percentage of predicted mature height at a given age) with an established indicator of maturity [skeletal age (SA)] in youth American football players. DESIGN: Cross-sectional. SETTING: Two communities in central Michigan. PARTICIPANTS: 143 youth football players 9.27 to 14.24 years. METHODS: Height and weight were measured, and hand-wrist radiographs were taken. SA assessed with the Fels method was the criterion measure of maturity status. Chronological age (CA), height, and weight of the player and midparent height were used to predict mature height; current height of the player was expressed as a percentage of his predicted mature height as a noninvasive estimate of biological maturity status. MAIN OUTCOME MEASURE: Boys' maturation was classified as late, on time, or early maturing on the basis of the difference between SA and CA and of present height expressed as a percentage of predicted mature height. Kappa coefficients and Spearman rank-order correlations were calculated. Characteristics of players concordant and discordant for maturity classification with SA and percentage of predicted mature height were compared with MANCOVA. RESULTS: Concordance between methods of maturity classification was 62%. The Kappa coefficient, 0.46 (95% CI 0.19 to 0.59) and Spearman rank-order correlation, rs = 0.52 (P < 0.001) were moderate. Players discordant for maturity status varied in midparent height and percentage of predicted mature height, but not in predicted mature height. CONCLUSION: Percentage of predicted mature height is a reasonably valid estimate of biological maturity status in this sample of youth football players.     

Validation of a blood-sampling method for the measurement of 99mTc-methylene diphosphonate skeletal plasma clearance.

Quantitative studies of bone using (99m)Tc-methylene diphosphonate (MDP) reflect bone remodeling. The simplest method of evaluating (99m)Tc-MDP kinetics involves taking multiple blood samples and measuring total clearance (K(total)) from the area under the plasma curve (AUC) and deriving bone clearance (K(bone)) by subtracting glomerular filtration rate (GFR) from K(total). However, the accuracy of the AUC method is uncertain because of assumptions that the terminal exponential is reached by 2 h and that the rate constant k(4), representing the backflow of tracer from bone to plasma, is negligibly small. The aim of this study was to validate the accuracy of the AUC method by comparing K(bone) values obtained by that method with those obtained by gamma-camera imaging. METHODS: Seventy-one patients were injected with 600 MBq of (99m)Tc-MDP. For the first 22 patients, whole-body images were acquired at 15 min and at 1, 2, 3, and 4 h after injection, whereas the remaining 49 were imaged at 15 min and at 1 and 3 h. Two-minute static images of the thighs were acquired immediately before each whole-body scan. Multiple blood samples were taken between 5 min and 4 h, and free (99m)Tc-MDP was measured using ultrafiltration. Two gamma-camera methods were used to evaluate K(bone): the Patlak plot method and the Brenner method, which is based on measuring soft-tissue uptake in the thighs. The soft-tissue data were also used to measure k(4). RESULTS: The soft-tissue data gave a k(4) value of 0.0003 min(-1) (95% confidence interval, 0-0.0008 min(-1)). The mean (+/-SD) (99m)Tc-MDP K(bone) was 56.0 +/- 32.4 mL x min(-1) with the AUC method, 49.5 +/- 32.1 mL x min(-1) with the Patlak method, and 42.8 +/- 32.0 mL x min(-1) with the Brenner method. Correcting the AUC values of K(total) by factors of 0.95 and 0.90 gave K(bone) values in agreement with the Patlak and Brenner methods, respectively. CONCLUSION: Values of k(4) are too small to affect values of K(bone) measured using the AUC method. Correcting K(total) by factors in the range of 0.90-0.95 corrects for the error in the terminal exponential and brings K(bone) values measured using the AUC method into agreement with the gamma-camera results.     

Validation of a digital videodensitometric program analysis for measurement of left ventricular ejection fraction

Left ventricular (LV) function was studied in 30 patients using digital subtraction angiography by the intravenous approach. Each ventriculogram was processed with a specific videodensitometric analysis to determine LV ejection fraction. The program was verified in an experimental set-up consisting of nine latex balloons filled with contrast medium. Its validation has been established by comparing videodensitometric results with classical results supplied by geometric methods. A good correlation was obtained (r = 0.9449) and, furthermore, with experimental models, videodensitometric analysis seemed to be more accurate than geometric analysis. Digital videodensitometry appears to be a valuable and accurate method for quantifying LV function, and a promising technique for determination of the real volumes.     

CT measurement of femoral anteversion angle in patients with unilateral developmental hip dysplasia: A comparative study between 2D and 3D techniques

Objective

To compare the accuracy of 2D and 3D CT measurements of femoral anteversion angle, in pediatric patients with developmental hip dysplasia.

Ulnar variance and skeletal maturity of radius and ulna in female gymnasts.

It is has been suggested that repetitive loading on the distal end of the radius in elite gymnasts may lead to epiphyseal changes, a premature closure (union) of the radius growth plate, and ulnar overgrowth. PURPOSE: It is hypothesized that ulnar overgrowth in female gymnasts is associated with advanced maturity status and early onset of epiphyseal closure of the radius, and later maturity status and later onset of epiphyseal closure of the ulnar. METHODS: Posterior-anterior radiographs of 201 female gymnasts, participants of the 1987 World Championships Artistic Gymnastics, were used to measure ulnar overgrowth, to determine skeletal maturation of the hand and wrist with the Tanner-Whitehouse technique, and to determine the maturity status of the radius and ulna separately, particularly with regard to the onset of epiphyseal closure. To test the hypothesis, extreme quintiles for ulnar overgrowth were contrasted for skeletal maturation of the hand and wrist and for maturity stages of the radius and ulna as defined by the Tanner-Whitehouse criteria. RESULTS: Female gymnasts who demonstrate ulnar overgrowth are skeletally more advanced in maturity status of the entire hand-wrist compared with gymnasts who did not show ulnar overgrowth. There were, however, no differences between gymnasts in the extreme quintiles of ulnar overgrowth in the maturation of the radius, although gymnasts with ulnar overgrowth show more advanced maturity status of the ulna. CONCLUSIONS: Ulnar overgrowth is thus not apparently associated with advanced maturity of the distal radial epiphysis as defined in protocols for assessing skeletal maturity and does not apparently lead to premature epiphyseal closure of the distal radius.     

Value of computed tomography in congenital hip dysplasia and hip luxation

A lot of methods of measurement have been developed to record precisely the degrees of luxation and the deviations from the normal form in the hip joints of the child and adult. The orthopaedic surgeon needs those data for a preoperative "coxometric program" before performing acetabuloplastic operations with osteotomy, osteotomy of the pelvis and combined operations. Computed tomography yields a series of informations and of possibilities of measurements which can determine the operative procedure in particular. These informations concern among other things the dimensions of the dysplasia of the acetabulum in the horizontal plane with the extension of the posterior lip and the angle of the acetabular opening, furthermore the physiological or pathological congruence between the head of the femur and the acetabulum, the angle of antetorsion of the neck of the femur and, in the small infant, the direct noninvasive imaging of the tube of the capsule with imaging of possible obstacles to reposition.     

Phantom studies of triple photon absorptiometry and bone mineral measurement at a hip prosthesis.

The feasibility of using triple photon absorptiometry (TPA) for the measurement of bone mineral mass about a hip prosthesis was examined. A theoretical expression describing the variance of TPA measurements was verified using a triple photon source and phantom materials which simulate the soft tissue-bone mineral-metal prosthesis system. The expression for the variance was used to determine an optimized set of photon energies. It was shown that a precision of 3% could be obtained for reasonable measurement times using this optimized set of energies, and that TPA should be a feasible approach for measurement of bone mineral about a hip prosthesis.     

发育性髋关节发育不良的外科治疗分析

目的：探讨发育性髋关节发育不良的治疗方法及疗效。方法：对26例发育性髋关节发育不良的治疗效果进行回顾性分析,治疗方法包括Pavlik吊带、蛙式石膏、Salter截骨、Pemberton截骨、Steel截骨、Chairi截骨及复合股骨近端截骨治疗。结果：Pavlik吊带2例为优。蛙式石膏4例,优1例,良1例,差2例。Salter截骨14髋,优5例,良4例,可4例,差1例。Pemberton截骨8髋,优5例,良3例。Steel截骨1例可。Chairi截骨2例优。结论：根据病情采用不同的治疗方法是提高发育性髋关节发育不良治疗效果的重要手段。     

The extent of Crohn's disease. Radiological measurements. Correlation with surgical findings

Twenty-three patients with small intestinal Crohn's disease were studied by barium-methylcellulose infusion. All patients underwent surgery within 1-24 months (average 7 months). The extent of the lesions and the small bowel length were radiologically evaluated by means of a map measurer. The same measurements were performed at surgery. Radiological and surgical data concerning the extent of enteritis were statistically correlated (r = 0.7). The correlation between radiological and surgical measurements of total small bowel length was not significant.     

Validation of 13C NMR measurement of human skeletal muscle glycogen by direct biochemical assay of needle biopsy samples.

Recent developments in 13C nuclear magnetic resonance (NMR) spectroscopy have permitted noninvasive assessment of glycogen concentration in human skeletal muscle. Before these indirect measurements could be accepted as accurate, it was essential that validation should be carried out by comparing the widely used method of muscle biopsy and direct biochemical assay for glycogen concentration with measurement by NMR. Eight normal subjects underwent six NMR scans of gastrocnemius and three biopsies of the same muscle on the same day. The overall mean for muscle glycogen concentration was 87.4 mM by NMR and 88.3 mM by biopsy. There was a close correlation between the pairs of observations on each subject (R = 0.95; P less than 0.0001). The mean coefficient of variation for NMR measurement was 4.3 +/- 2.1% and that for biopsy was 9.3 +/- 5.9%. The performance of the muscle biopsies was accompanied by a small but significant rise in plasma-free fatty acids (529 +/- 157 to 667 +/- 250; P less than 0.01), epinephrine (17 +/- 6 to 25 +/- 8 pg/ml; P less than 0.02), and norepinephrine (318 +/- 119 to 400 +/- 140 pg/ml; P less than 0.02) but no change in plasma glucose, plasma insulin, nor muscle glycogen concentration assessed by NMR. The study demonstrates that in vivo 13C NMR measurement of human muscle glycogen can be regarded as accurate, and the technique is associated with a higher precision that biopsy with direct biochemical assessment.     

Validation of US-guided percutaneous venous access and manual compression for studies in swine

PURPOSE: To validate, in swine, the feasibility, efficacy, and safety of ultrasound (US)-guided vascular access, with manual compression for hemostasis, as an alternative to surgical cutdown. MATERIALS AND METHODS: US-guided femoral vein access was attempted 22 times in eight pigs. Bilateral access was performed in the initial procedure (eight pigs, 16 veins), and unilateral access was performed during follow-up procedures (six pigs, six veins). Two sheath sizes were used: 9 F (in eight veins) and 8 F (in 14 veins). At the completion of each procedure, the vascular sheaths were removed and hemostasis was attempted by manual compression. All animals were followed clinically for at least 24 hours after each access procedure. Bilateral US images of the femoral region were obtained in six pigs (12 puncture sites) 2 weeks after the initial procedure. RESULTS: US-guided femoral vein access was successful in all 22 attempts, including 16 first-time insertions and six subsequent insertions. Hemostasis was achieved with 5 minutes of manual compression in all 22 procedures. No groin complications were identified on clinical follow-up or at necropsy. US imaging of the 12 femoral access points in the six pigs that underwent more than one procedure demonstrated normal femoral veins that compressed appropriately with no evidence of thrombosis or hematoma. CONCLUSION: US-guided femoral vein access, with manual compression used for hemostasis, is a safe and effective method for venous interventions in swine. Moreover, this percutaneous technique allows the same vessel to be reused.     

Radiological features of the visceral and skeletal involvement of hemochromatosis

Hemochromatosis is a multisystem disorder produced by the excessive accumulation of iron in visceral organs and the musculoskeletal system. Clinically the disease may be silent, but characteristic radiological features may point to the diagnosis. The increased iron stores in the organs involved, especially in the liver and pancreas, result in an increased attenuation at unenhanced CT and an decreased signal intensity at MR imaging. Hemochromatosis arthropathy includes degenerative osteoarthritis and chondrocalcinosis. The distribution of the arthropathy is distinctive, but not unique, frequently affecting the second and third metacarpophalangeal joints of the hand. Received 7 October 1996; Revision received 8 January 1997; Accepted 12 February 1997