[Axial deformities of the lower extremity in the frontal plane : From physiological development to pathological and possible long-term consequences]

The Coronal Alignment of Lower Limbs in the Adolescent Football and Ice Hockey Players

Background

To investigate the influence of sport-specific activities on coronal axial alignment of the lower limbs in adolescent football and ice hockey players.

Methods

This cross-sectional study targeted healthy adolescent male football and ice hockey players with at least 3 years of sports participation. 90 football and 38 ice hockey players aged 12-16 years were divided into five age-matched subgroups. Coronal alignment of the lower limbs was determined by measuring the players' intercondylar or intermalleolar (ICD-IMD) distance with a custom-made calliper. In addition, their sports history was recorded. An age-matched comparison between the two sports groups was performed using the two-way model ANOVA and a multiple regression model for ICD-IMD was constructed. Results were additionally compared with age-matched data from the general population published in recent literature.

Results

A statistically significant increase in ICD-IMD values (p < 0.05) was found between 12 (football 0 mm; ice hockey - 64 mm) and 16 years (football 340 mm; ice hockey 310 mm) in both sports groups. Results of regression analysis of pooled group data showed that ICD-IMD has low positive correlation (r = 0.407; r2 = 0.168; p < 0.05) with time of participation in sport, but no association with age of athletes at the start of their sport participation (r = - 0.018; r2 = 0.000; p > 0.05). There were no statistically significant differences between the two groups at any time point. Both sports groups showed a significant increase in ICD-IMD values (mean 198 mm) after the age of 14 compared to the general population.

Conclusions

Participation in football and ice hockey is associated with a similar increase in ICD-IMD in the adolescent years in male athletes. The observed increase was higher in both groups of athletes than in their peers who do not regularly participate in sports.

Level of Evidence

Level 4 (case series).

Intra- and interobserver reliability analysis of pediatric lower limb parameters on digital long leg radiographs

BACKGROUND

Malalignments of the lower extremity are common reasons for orthopedic consultation because it may lead to osteoarthritis in adulthood. An accurate and reliable radiological assessment of lower limb alignment in children and adolescents is essential for clinical decision-making on treatment of limb deformities and for regular control after a surgical intervention.

OBJECTIVE

First, does the analysis of full-length standing anteroposterior radiographs show a good intra- and interobserver reliability? Second, which parameter is most susceptible to observer-dependent errors? Third, what is the Standard Error of Measurement (SEM_95%) of the absolute femoral and tibial length?

METHODS

Two observers evaluated digital radiographs of 144 legs from 36 children and adolescents with pathological valgus alignment before a temporary hemiepiphysiodesis and before implant removal. Parameters included Mechanical Femorotibial Angle (MFA), Mechanical Axis Deviation (MAD), mechanical Lateral Distal Femoral Angle (mLDFA), mechanical Medial Proximal Tibial Angle (mMPTA), mechanical Lateral Proximal Femoral Angle (mLPFA), mechanical Lateral Distal Tibial Angle (mLDTA), Joint Line Convergence Angle (JLCA), femur length, tibial length. Intra- and interobserver reliability (ICC_2,1), SEM_95% and proportional errors were calculated.

RESULTS

The intra- and interobserver reliability for almost all measurements was found to be good to excellent (Intra-ICC_2,1: 0.849-0.999; Inter-ICC_2,1: 0.864-0.996). The SEM_95% of both observers was found to be ± 1.39° (MFA), ± 3.31 mm (MAD), ± 1.06° (mLDFA) and ± 1.29° (mMPTA). The proportional error of MAD and MFA is comparable (47.29% vs. 46.33%). The relevant knee joint surface angles show a lower proportional error for mLDFA (42.40%) than for mMPTA (51.60%). JLCA has a proportional error of 138%. Furthermore, the SEM_95% for the absolute values of the femoral and tibial length was 4.53 mm for the femur and 3.12 mm for the tibia.

CONCLUSIONS

In conclusion, a precise malalignment measurement and the knowledge about SEM_95% of the respective parameters are crucial for correct surgical or nonsurgical treatment. The susceptibility to error must be considered when interpreting malalignment analysis and must be considered when planning a surgical intervention. The results of the present study elucidate that MAD and MFA are equally susceptible to observer-dependent errors. This study shows good to excellent intra- and interobserver ICCs for all leg alignment parameters and joint surface angles, except for JLCA.

TRIAL REGISTRATION

This study was registered with DRKS (German Clinical Trials Register) under the number DRKS00015053.

LEVEL OF EVIDENCE

I, Diagnostic Study.