[Axes of the legs in childhood. What is pathologic?]

[Pediatric developmental disorders of the musculoskeletal system]

CLINICAL/METHODICAL ISSUE

In pediatric musculoskeletal disorders, a distinction is made between normal and abnormal development.

STANDARD RADIOLOGICAL METHODS

X‑ray examination is the standard diagnostic procedure.

METHODOLOGICAL INNOVATIONS

Cross-sectional imaging, such as magnetic resonance imaging (MRI), computed tomography (CT), and ultrasonography (US) are increasingly used.

PERFORMANCE

X‑ray imaging is still the examination method of choice but can be supplemented by cross-sectional imaging depending on clinical situation.

ACHIEVEMENTS

Cross-sectional imaging is helpful and necessary in many cases but significantly more time-consuming and costly than x‑ray examinations.

PRACTICAL RECOMMENDATIONS

Initially standard x‑rays should be taken, which can then be supplemented with cross-sectional imaging depending on the result and clinical question (MRI and US are preferred as there is no radiation).

Age related changes in the Q angle of non-professional football players

Background

Football practice involves a great muscular demand, leading to the development of the lower limbs that, on occasions, can cause deviations from the normal anthropometric values. The quadriceps angle (Q angle) is a value often taken as a reference for the alignment of the lower limbs.

Objective

To observe the changes of the Q angle in young football players, because of muscular effort, analyzing the differences between four groups of different ages and to determine whether the playing position might influence these variations.

Methods

A cross sectional study was carried out with 104 male subjects divided into four groups according to age: under 8 years-old, 8-17 years-old, 17-21 years-old and over 21 years-old. A photograph was taken in standing position and the Q angle was plotted with KINOVEA® software. As for the reliability of the measurements, intraclass intra and interobserver coefficient were 0.958 and 0.860 respectively. The study was conducted in mid-season.

Results

Q angle value is greater in those under 8 years of age and decreases gradually and significantly (p < 0.005) until 17-21 years of age, where it stabilizes at values of 5.73° ± 2.78 for right Q angle and 5.88° ± 2.55 for left Q angle. Two way ANOVA demonstrated a significant group*position interaction for goalkeepers with a medium effect size in both angles (p < 0.001) with a medium effect (η² Right Q angle = 0.31; η² Left Q angle = 0.37). The values remain unchanged in subjects over 21 years of age (p > 0.005), except for goalkeepers, who suffered a difference in the evolution of the angle within their age category (p < 0.005) and with a high effect size with the other positions (value > 0.8) except forward (value < 0.5).

Conclusion

This study determines that the Q angle in football players decreases with growth, reaching values below 15° at the end of development. Playing positions only influence players over the age of 21, and the Q-angle of goalkeepers is greater than that of other players.

Biomechanical Performance of BoneHelix® Compared with Elastic Stable Intramedullary Nailing (ESIN) in a Pediatric Tibia Fracture Model

Tibial shaft fractures are common injuries in the pediatric and adolescent populations. Elastic stable intramedullary nailing (ESIN) is the treatment of choice for cases that require surgical stabilization. A new intramedullary device, BoneHelix^® (BH), may be an alternative for use with fractures that cannot be satisfactorily stabilized with ESIN. This study aimed to assess the biomechanical performance of BH compared with ESIN in a porcine tibia fracture model, observing cyclic fatigue and load to failure. Computed tomography was used to monitor the implant position and to rule out unintended damage. No implant or bone failure occurred during the fatigue testing. An increase in the cumulative plastic displacement was observed in both test groups over the loading cycles applied. Both implant–bone constructs displayed a trend toward closure of the osteotomy gap. During the load-to-failure test, the average loads at failure in specimens instrumented with ESIN and BH were 5364 N (±723) and 4350 N (±893), respectively, which were not statistically significant (p = 0.11). The values of both groups were two to three times higher than the estimated maximal load (2000 N) during physiological weight bearing. The biomechanical results thus indicate equivalent performance and stability by the implants tested.

Development of Garments with Elastic Straps and Pressure Applicator (GESPA) and "GVcorrect" App to Follow the Changes in Lower-Extremity Alignment (Genu Valgum)-A Pilot Study

BACKGROUND

There are non-invasive methods of correcting genu valgum (GV), but to date, there is no method to evaluate mechanotherapeutic intervention that does not restrict child's natural movements while the process is on-going so that timely decisions could be made on effectiveness of intervention. The aim of study was to develop and assess the comfortability of garments with elastic straps and pressure applicator (GESPA) and the reliability and user-friendliness of "GVcorrect" app, which aims to catch the elastic straps' pressure level (mN).

METHODS

6 children (5-7 y) with intermalleolar distance ≥5 cm wore GESPA daily for 3 months. Anthropometrical and goniometrical measurements were done according to standard technique; tone and biomechanical parameters of skeletal muscles determined with MyotonPRO; feedback about GESPA and "GVcorrect" collected via questionnaire.

RESULTS

Based on feedback from children and parents, new, more comfortable and user-friendly GESPA were designed; several updates were made to "GVcorrect" app; new goals were set for the next phase of the study.

CONCLUSIONS

GESPA and the "GVcorrect" app serve their purpose, but there are still a number of important limitations that need to be removed before the product can be marketed. The study continues with product development until a medical device certificate is obtained.

[Radiographic analysis of limb malalignment in the frontal plane]

Radiographic measurement of the lower limb alignment in the frontal plane is used to assess limb deformity, to plan corrective surgery and for follow-up. It is essential that age-related normal lower limb alignment and joint orientation angles are known before planning surgical treatment. EOS (EOS™ Imaging, Paris, France) can lead to supplemental information, especially in cases of severe multidimensional joint malalignment. It allows 3D reconstruction of a bone model of the limb to assess multi-dimensional deformity.

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

BACKGROUND

From birth to the end of growth, leg axes undergo physiological changes. Congenital, idiopathic or secondary deformities of the lower extremities are considered as a pre-arthrosis. A detailed clinical examination is of primary importance. On the basis of the established preventive examinations, predominantly asymptomatic deformities can be distinguished from age-typical physiological axis deviations at an early stage.

THERAPY

There is a variety of conservative and surgical therapy options. In most cases, the spontaneous course of development can be waited for, depending on the deformity and the associated restrictions. It is important to recognize the right time for an intervention. Usually, surgical interventions are necessary, including guided growth by permanent and partial arrest of the growth plate or osteotomies. The aim is to restore the anatomical axial alignment and thus prevent the development of osteoarthritis. A missed intervention often leads to an early endoprosthetic replacement in adulthood.

Temporary hemiepiphysiodesis for correcting idiopathic and pathologic deformities of the knee: A retrospective analysis of 355 cases

BACKGROUND

Hemiepiphysiodesis is a well-established treatment option in cases of pathologic deformities and leg discrepancies during evolution. The aim of this study was to evaluate the postoperative angular measurement, correction correlated with age at operation time, and postoperative complication rate.

MATERIAL AND METHODS

A total of 355 patients were treated with 887 8-plates between April 2007 and January 2013. Their mean age was 12.18 years (range four to 16 years), and the mean time to axis correction was 17.32 months (range two to 62 months). We analysed the entire population and also performed subgroup analyses for idiopathic, pathologic, varus, valgus and leg length discrepancy.

RESULTS

The mean durations (time from (hemi-) epiphysiodesis to implant removal) in the idiopathic and pathologic groups were 13.24 and 21.3 months, respectively. The time to implant removal was 18.39 months for idiopathic varus deformities and 11.07 months for idiopathic valgus deformities. For the pathologic deformity group it was 24.9 and 20 months in the varus and valgus subgroups, respectively.

CONCLUSIONS

Hemiepiphysiodesis is a well-established treatment option to correct angular deformities. The rate of correction was slower and less successful in pathologic deformities and for leg length discrepancies. This suggests that earlier intervention is appropriate for these patients. A higher body mass index (BMI) was observed for valgus deformity, but no correlation was present between BMI and durability.

Closed reduction with crossed Kirschner wire fixation for displaced supracondylar femoral fractures in young children

Supracondylar femoral fractures are uncommon in children, but may result in various deformities. Though many approaches have been used to manage them, there is no literally approved standard yet.From 2015 to 2017, 12 young children at the average age of 2.5 years old (range 3.6-1.6) with displaced supracondylar fractures were admitted to our department and received closed reduction with crossed Kirschner wire (K-wire) fixation as treatment. After the surgeries, we performed follow-up to every patient at the average length of 26 months (range 24-30) and used the Knee Society Score scale to evaluate the outcome.Fracture healing was observed within 10 weeks for all patients and walking was resumed between 10 to 13 weeks. No patient reported a valgus deformity more than 10°, neurovascular injury or knee infection. The average limb length discrepancy was 0.4 cm at the end of our follow-up. Every patient had perfect score on the Knee Society Score scale.Our study suggests that closed reduction with percutaneous crossed Kirschner wire is a favorable method for displaced supracondylar femoral fractures in young children.

Treatment of genu valgum in children by means of temporary hemiepiphysiodesis using eight-plates: short-term findings

Background

Idiopathic genu valgum is a frequently diagnosed growth disorder in adolescence. Whenever the possibilities of conservative therapy have been exhausted, leg straightening by means of hemiepiphysiodesis has become the standard form of treatment. Because of their flexible screw-plate connection, eight-Plates have been reported in the literature to lead to lower complications regarding implant loosening and fracture compared to other implants.

The aim of this retrospective survey was to analyse our own patient population who were treated for genu valgum by means of temporary hemiepiphysiodesis near the knee using eight-Plates to modulate growth.

Methods

Between July 2007 and July 2015, 198 eight-Plates were implanted near the knee in 132 children suffering from genu valgum to modulate growth. Depending on the deformity analysis, an eight-Plate was implanted on the distal medial femur and/or the proximal medial tibia. By December 2015, they had been removed from 105 patients. The etiology of genu valgum was mainly idiopathic or associated withobesity. Evaluation was carried out clinically and radiologically (whole-leg X-ray in standing) including determination of the joint angles.

Results

The median follow-up period was about 46 months (12–102 months). The median age at implantation was 12.7 +/−6.76 years. Of the 105 patients, 45.7% (n = 48) were girls. The eight-Plates remained in place for a median period of 13 +/−1.76 months. Irrespective of the location of hemiepiphysiodesis, the intermalleolar distance was corrected to a median of 0 +/−2.1 cm while the anatomical femorotibial angle was corrected by on average 9 +/−2.7 °Mechanical lateral distal femoral angle changed an average 7 +/− 7.72 degrees. Medial proximal tibial angle changed an average 4 +/− 6.02 degrees. Complications necessitating surgery occurred in 2.8% of cases (1 wound infection, 3 corrective osteotomies following overcorrection).

Conclusion

Temporary hemiepiphysiodesis using eight-Plates is a gentle, simple and effective procedure used to treat genu valgum by modulating growth. Slight overcorrection is desirable due to the rebound phenomenon, especially in young patients with high growth potential and risk groups such as obese children. In adolescents with only low growth potential (older than 14 years), owing to the low correction potential, the indication should be strictly reviewed and the possible failure of therapy should be discussed with the patient. No differences were observed regarding the location of the implanted eight-Plates (femoral or tibial).

[Special topics in pediatric orthopedics: options and limits of growth guidance]

BACKGROUND

A main task of pediatric orthopedics is the treatment of legs of different lengths or misshapen legs. Whereas for adult patients complicated and invasive operative interventions are necessary, the growth potential of the epiphysial plate can be utilized in childhood and adolescence to correct leg length differences and leg axis deformities.

THERAPY

Epiphysiodesis leads to a guidance of growth via a temporary or permanent and partial or complete blockade of the epiphysial plate depending on the indications. This method is principally a less invasive procedure with few complications.

CONCLUSION

Careful preoperative assessment of the indications and planning, precise operative technique and attentive postoperative control investigations are absolutely essential for successful treatment.

[Evaluation of the usefulness of the EOS 2D/3D system for the measurement of lower limbs anatomical and biomechanical parameters in children]

INTRODUCTION

Lower limbs anatomical and biomechanical parameters are essential in several paediatric orthopaedic disease, which makes their exact measurement necessary.

AIM

The aim of the author was to evaluate the reliability of the EOS 2D/3D System, a 3D reconstruction capable imaging device in children.

METHOD

3D reconstructions were performed in 523 cases aged between 2 and 16 years in whom no abnormality influencing lower limbs biomechanics was observed. For statistical analysis intraclass correlation, paired-samples t-test, Spearman-correlation and Welch-test were used.

RESULTS

Excellent results were found for all parameters in reliability test used by the operator. The step-forward position used during the examination influenced the sagittal tibiofemoral angle only. All examined parameters showed significant correlation with age and gender. Height correlated with neck-shaft angle, hip-knee shift, femoral and tibial torsion only.

CONCLUSIONS

The EOS technology proved to be an appropriate method to measure lower limbs anatomical parameters in children. Changes in these parameters during development correlated with age and gender.

The physiological range of femoral antetorsion

INTRODUCTION

Intramedullary nailing is a common method for fixation of femoral diaphyseal shaft fractures. However, postoperative malrotation does occur in 20-30 % of patients, as intraoperative assessment of antetorsion remains difficult. The estimated average antetorsion angle is 15°. However, it is not clear whether antetorsion correlates with individual characteristics such as age, gender, or femoral length. This information may help surgeons to better estimate the correct target rotation before and during surgery.

MATERIALS AND METHODS

The antetorsion of 211 healthy femurs was measured using torsion difference CTs according to the technique published by Jend. Correlations with age, gender, and femoral length were calculated.

RESULTS

A significant negative correlation of age and antetorsion was found for women aged 0-20. Older women and men did not show any correlation between antetorsion and age. There was no correlation between antetorsion and femoral length. Mean values differed between 17.8° ± 8.9° and 22.7° ± 10.7° in women and 15.3° ± 8.0° and 21.4° ± 9.7° in men.

CONCLUSIONS

Antetorsion is mostly independent of body height and age, the latter except in women younger than 20. The so-far-estimated physiologic antetorsion of about 15° seems to be a little higher in most people.

Femoral torsion: reliability and validity of the trochanteric prominence angle test

Influence of femoral torsion on femoroacetabular impingement and other hip conditions is not well documented and its assessment by imaging methods during clinical work-up is not routinely performed. We studied whether physical examination could reliably measure or at least screen for gross anomalies of femoral torsion or if appropriate imaging should routinely be performed. Assessing femoral torsion of 45 volunteers using the "trochanteric prominence angle test" and magnetic resonance imaging (MRI), inter- and intra-observer reliability ranged from poor to moderate and agreement with MRI values was only fair. Considering a 5° to 10° difference of femoral torsion as clinically relevant, physical examination failed to match MRI values within ±10° in more than 50%. Arbitrarily defining thresholds for pathological femoral torsion, the "trochanteric prominence angle test" could not recognise torsions outside the >30°/<0° range and diagnosed torsions outside the >20°/<10° range with a sensitivity of 18%-75% and a specificity of 58%-98% only. Physical assessment of femoral torsion using the "trochanteric prominence angle test" does not allow reliable measurement or screening for gross anomalies. We therefore integrate an adapted MRI protocol allowing measurement of femoral torsion within our clinical work up.

Normal lower-extremity alignment parameters in healthy Southern Chinese adults as a guide in total knee arthroplasty

Alignment parameters in 199 healthy lower extremities of Southern Chinese adults and the parameters' anatomical influence were studied in a standardized frontal plane for the selection of the proper valgus angle of the distal femoral cut in total knee arthroplasty. The average hip-knee-ankle angle was 179.8 degrees +/- 2.4 degrees. The average femoral physiologic valgus angle was 5.1 degrees +/- 0.9 degrees (95% confidence interval, 4.9 degrees -5.2 degrees). The hip-knee-ankle angle showed a significantly inverse correlation with the femoral physiologic valgus angle. The results indicate that choosing 5 degrees as the valgus angle for the femoral distal cut in total knee arthroplasty is safe for most of Southern Chinese ethnicity, and it is reasonable to adjust the femoral valgus angle to 7 degrees or 3 degrees in the few patients with severe genu varum or genu valgum.

[Indications and results of corrective pelvic osteotomies in developmental dysplasia of the hip]

BACKGROUND

Joint-preserving reconstructive surgeries in children and adolescents remain challenging for orthopaedists with regard to indication and surgical technique. Besides skeletal maturity and tissue quality at the time of surgery, the kind and degree of deformity, the causative pathologies in secondary dysplasias, and the prognosis have to be considered when deciding for or against a surgical procedure. Developmental dysplasia of the hip (DDH) is the most frequent deformity that indicates reorienting surgery on the hip joint in children and adolescents. The aim of these procedures is to prevent early secondary osteoarthritis. For patients and families as well as for the orthopaedist, risk-benefit analysis is of major interest.

METHODS

In this study, the surgical techniques and specialties of different reconstructive operations are presented. Based on a review of the literature, the results of defined surgical methods are discussed and compared with own experiences.

RESULTS

Only limited information is available about the clinical long-term outcome after defined reconstructing surgery on the hip joint in children and adolescents. The degree of the deformity, the age of onset, and the surgical experience of the orthopaedist are crucial factors in decision making for or against a surgical treatment. In early childhood, acetabuloplasty and Salter osteotomy are widely accepted to correct DDH. Triple and periacetabular osteotomies are preferred and have shown promising results in late adolescence and young adults. When the triradiate cartilage (growth plate) is closed, good outcomes can be achieved by the Ganz osteotomy. Intertrochanteric varus and derotation osteotomies of the femur may serve as additional procedures for pelvic osteotomies and are rarely indicated as a single procedure today.

CONCLUSION

Reconstructive surgery on the hip joint improves function and may prevent early osteoarthritis and delay progression of cartilage degeneration in most patients when the indication and surgical technique are appropriate.