Comparison of the Paley Method Using Chronological Age with Use of Skeletal Maturity for Predicting Mature Limb Length in Children

Sanders, James O.; Howell, James; Xing Qiu
June 2011
Journal of Bone & Joint Surgery, American Volume;6/1/2011, Vol. 93-A Issue 11, p1051
Academic Journal
Background: Treating patients with congenital or acquired limb-length inequality requires accurate estimations of limb length at skeletal maturity. There is controversy over the best indicator of maturity to be used for limb-length calculations. Paley popularized the multiplier method, in which chronological age is used, which has the virtue of simplicity but does not account for the wide variance in timing of the adolescent growth spurt. The purpose of this study was to determine whether the use of chronological age or the level of skeletal maturity provides more accurate limb-length predictions. Methods: We identified patients with limb-length inequality, for whom scanograms had been obtained before and at maturity, and who had had no surgical procedures on their normal lower limb. Skeletal maturity was determined with use of the Greulich and Pyle atlas, Tanner-Whitehouse-3 method, and simplified stages described by Sanders et al. The length of the lower extremity was compared with the ultimate limb length and the actual multiplier (final limb length divided by current limb length) for each point in time. A linear model was used to determine the log-transformed multipliers for the level of skeletal maturity, and Paley's multipliers were used for chronological age. Residual standard errors were deter- mined to compare the results of the methods. We also conducted piecewise linear regression on each of the methods and used the residual standard errors to rank their performance and cross-validated the results. Results: We identified twenty-four patients (twelve girls and twelve boys) who met the study criteria. Most subjects had had multiple scanograms along with skeletal age radiographs (average, 4.5) at different ages. When all ages are considered, the Paley method had the best overall performance, with residual standard errors that were typically ⩽5 cm. However, the Paley method did not perform best for subjects at stage-2 skeletal maturity or above; in those cases, skeletal-maturity-based predictions had residual standard errors of <2 cm. Conclusions: While the Paley method, which is based on chronological age, provides reasonable estimates of ultimate limb length for most patients, use of skeletal-maturity determinations appears to provide better predictions of mature limb length during adolescence.


Related Articles

  • On local influence for elliptical linear models. Shuangzhe Liu // Statistical Papers;2000, Vol. 41 Issue 2, p211 

    Presents a study that examined the use of local influence method in elliptical linear regression models. Background on elliptical linear models; Details on the local influence method; Analysis of the predictor and response perturbations.

  • Reduced-rank vector generalized linear models. Yee, Thomas W; Hastie, Trevor J // Statistical Modelling: An International Journal;2003, Vol. 3 Issue 1, p15 

    Reduced-rank regression is a method with great potential for dimension reduction but has found few applications in applied statistics. To address this, reduced-rank regression is proposed for the class of vector generalized linear models (VGLMs), which is very large. The resulting class, which...

  • A Note on the Consistency of LS Estimates in Linear Models. Chen, Xiru // Chinese Annals of Mathematics;Oct2001, Vol. 22 Issue 4, p471 

    It is well known that when the random errors are iid. with finite variance, the week and the strong consistency of LS estimate of multiple regression coefficients are equivalent. This note, by constructing a counter-example, shows that this equivalence no longer holds true in case that the...

  • "Neighborhood" Influence on the Formation of National Identity in Taiwan: Spatial Regression with Disjoint Neighborhoods. Tse-Min Lin; Chin-En Wu; Feng-Yu Lee // Political Research Quarterly;Mar2006, Vol. 59 Issue 1, p35 

    This article argues that, like fashion, national identity may be influenced by "neighbors" in a broadly defined sense. Inspired by models of collective choice, we hypothesize that, in Taiwan, a subethnically divided society facing a dilemma in its relationship with China, township residents and...

  • Adjusting for bias and unmeasured confounding in Mendelian randomization studies with binary responses. Tom M Palmer; John R Thompson; Martin D Tobin; Nuala A Sheehan; Paul R Burton // International Journal of Epidemiology;Oct2008, Vol. 37 Issue 5, p1161 

    Background Mendelian randomization uses a carefully selected gene as an instrumental-variable (IV) to test or estimate an association between a phenotype and a disease. Classical IV analysis assumes linear relationships between the variables, but disease status is often binary and modelled by a...

  • Improving generalised estimating equations using quadratic inference functions. Qu, Annie; Lindsay, Bruce G.; Bing Li // Biometrika;Dec2000, Vol. 87 Issue 4, p823 

    Generalised estimating equations enable one to estimate regression parameters consistently in longitudinal data analysis even when the correlation structure is misspecified. However, under such misspecification, the estimator of the regression parameter can be inefficient. In this paper we...

  • An efficient design for model discrimination and parameter estimation in linear models. Biswas, Atanu; Chaudhuri, Probal // Biometrika;Sep2002, Vol. 89 Issue 3, p709 

    We consider experimental designs in a regression set-up where the unknown regression function belongs to a known family of nested linear models. The objective of our design is to select the correct model from the family of nested models as well as to estimate efficiently the parameters...

  • A linear fit gets the correct monotonicity directions. Malik Magdon-Ismail; Joseph Sill // Machine Learning;Jan2008, Vol. 70 Issue 1, p21 

    Abstract   Let f be a function on ℝ d that is monotonic in every variable. There are 2 d possible assignments to the directions of monotonicity (two per variable). We provide sufficient conditions under which the optimal linear model obtained from a least squares...

  • PROPERTIES OF THE LOG-BARRIER FUNCTION ON DEGENERATE NONLINEAR PROGRAMS. Wright, Stephen J.; Orban, Dominique // Mathematics of Operations Research;Aug2002, Vol. 27 Issue 3, p585 

    We examine the sequence of local minimizers of the log-barrier function for a nonlinear program near a solution at which second-order sufficient conditions and the Mangasarian-Fromovitz constraint qualification are satisfied, but the active constraint gradients are not necessarily linearly...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics