The impact of increased femoral antetorsion on gait deviations in healthy adolescents

Walking and Running of Children with Decreased Femoral Torsion

Understanding the implications of decreased femoral torsion on gait and running in children and adolescents might help orthopedic surgeons optimize treatment decisions. To date, there is limited evidence regarding the kinematic gait deviations between children with decreased femoral torsion and typically developing children, as well as the implications of the same on the adaptation of walking to running. A three-dimensional gait analysis study was undertaken to compare gait deviations during running and walking among patients with decreased femoral torsion (n = 15) and typically developing children (n = 11). Linear mixed models were utilized to establish comparisons within and between the two groups and investigate the relationship between clinical examination, spatial parameters, and the difference in hip rotation between running and walking. Patients exhibited increased external hip rotation during walking in comparison to controls, accompanied by higher peaks for the same as well as for knee valgus and external foot progression angle. A similar kinematic gait pattern was observed during running, with significant differences noted in peak knee valgus. In terms of variations from running to walking, patients internally rotated their initially externally rotated hip by 4°, whereas controls maintained the same internal hip rotation. Patients and controls displayed comparable kinematic gait deviations during running compared to walking. The passive hip range of motion, torsions, and velocity did not notably influence the variation in mean hip rotation from running to walking. This study underlines the potential of 3D gait kinematics to elucidate the functional implications of decreased FT and, hence, may contribute to clinical decision making.

Influence of femoral anteversion angle and neck-shaft angle on muscle forces and joint loading during walking

Femoral deformities, e.g. increased or decreased femoral anteversion (AVA) and neck-shaft angle (NSA), can lead to pathological gait patterns, altered joint loads, and degenerative joint diseases. The mechanism how femoral geometry influences muscle forces and joint load during walking is still not fully understood. The objective of our study was to investigate the influence of femoral AVA and NSA on muscle forces and joint loads during walking. We conducted a comprehensive musculoskeletal modelling study based on three-dimensional motion capture data of a healthy person with a typical gait pattern. We created 25 musculoskeletal models with a variety of NSA (93°-153°) and AVA (-12°-48°). For each model we calculated moment arms, muscle forces, muscle moments, co-contraction indices and joint loads using OpenSim. Multiple regression analyses were used to predict muscle activations, muscle moments, co-contraction indices, and joint contact forces based on the femoral geometry. We found a significant increase in co-contraction of hip and knee joint spanning muscles in models with increasing AVA and NSA, which led to a substantial increase in hip and knee joint contact forces. Decreased AVA and NSA had a minor impact on muscle and joint contact forces. Large AVA lead to increases in both knee and hip contact forces. Large NSA (153°) combined with large AVA (48°) led to increases in hip joint contact forces by five times body weight. Low NSA (108° and 93°) combined with large AVA (48°) led to two-fold increases in the second peak of the knee contact forces. Increased joint contact forces in models with increased AVA and NSA were linked to changes in hip muscle moment arms and compensatory increases in hip and knee muscle forces. Knowing the influence of femoral geometry on muscle forces and joint loads can help clinicians to improve treatment strategies in patients with femoral deformities.

The effect of functional calibration methods on gait kinematics in adolescents with idiopathic rotational deformity of the femur

BACKGROUND

Due to anatomical deviations, assumptions of the conventional calibration method for gait analysis may be violated in individuals with rotational deformities of the femur. Functional calibration methods were compared with conventional methods in this group for 1) localization of the hip joint center and orientation of the knee axis, and 2) gait kinematics.

METHODS

Twenty-four adolescents with idiopathic rotational deformity of the femur underwent gait analysis and a CT scan. During standing, distance between hip joint centers and knee axis orientation were compared between calibration methods, with CT serving as reference for hip joint center estimation. Gait kinematics were compared using statistical parametric mapping.

FINDINGS

The conventional calibration method estimated the hip joint center closer to the CT reference (4±12 mm more lateral) than the functional calibration method (26 ± 20 mm more lateral). Orientation of the knee joint axis was 2.6° less internal in the functional calibration method. During gait, statistical parametric mapping revealed significantly more hip flexion, less external hip rotation during the swing phase, less knee varus-valgus motion, and larger knee flexion angles when applying the functional method.

INTERPRETATION

Functional calibration methods were less accurate in determining the hip joint center location than the conventional calibration method and resulted in a knee joint axis that was less internally rotated. Importantly, there was less knee joint angle crosstalk during gait when using the functional method. Although differences between methods on gait kinematics were within clinically acceptable limits for the sagittal plane, relatively larger differences on transversal hip kinematics may hold clinical importance.

Does Increased Femoral Anteversion Can Cause Hip Abductor Muscle Weakness?

BACKGROUND

Increased femoral anteversion (IFA) causes functional problems (i.e., tripping, frequently falling, and fatigue) by affecting the pelvis and lower extremity biomechanics. In the frontal plane, increased contralateral pelvic drop and ipsilateral hip adduction, which are mainly considered deteriorated hip abductor muscle mechanisms, are associated with hip and knee injuries.

AIMS

The aim of this study was to examine the effects of femoral anteversion on hip abductor weakness and frontal plane pelvis-hip biomechanics during walking.

METHODS

The study included nine subjects with increased femoral anteversion and a control group of eleven subjects. Maximum isometric voluntary contraction (MIVC) values of the hip abductor muscles were measured with a handheld dynamometer. Three-dimensional gait analysis was performed for kinetic, kinematic, and temporo-spatial gait parameters. Non-parametric tests were used for statistical analysis (p < 0.05).

RESULTS

There was no significant difference found between the MIVC values of the IFA and control groups (p = 0.14). Moreover, no significant difference was determined between the ipsilateral peak hip adduction (p = 0.088) and contralateral pelvic drop (p = 0.149) in the stance phase. Additionally, there was no correlation between the peak hip adduction angle in the stance phase and normalized MIVC values in the IFA group (r = -0.198, p = 0.44), or in the control group (r = -0.174, p = 0.55). The deviations of pelvic rotation (p = 0.022), hip internal rotation (p = 0.003), and internal foot progression (p = 0.022), were found to be higher in the IFA group than in the controls.

CONCLUSIONS

IFA may not be associated with hip abductor muscle weakness, and it may not lead to the hip adduction and pelvic depression that can be seen in hip abductor weakness. Increased pelvic rotation and internal hip rotation during walking might be considered as a compensation for the femoral head-acetabulum alignment mechanism in the frontal plane.

The functional role of hip muscles during gait in patients with increased femoral anteversion

BACKGROUND

Femoral anteversion affects the lever arm and moment-generating capacity of the hip abductors, while an increased hip internal rotation during walking was proposed to be a compensatory mechanism to restore the abductive lever arm. Children with isolated increased femoral anteversion, however, do not always present a deficit in the net hip abduction moment during gait, suggesting that a more comprehensive understanding of the effect of morphology and motion on muscle forces and moments is needed to aid clinical decision making.

RESEARCH QUESTION

Are muscle contributions to hip joint moments and muscle forces altered in patients with increased femoral anteversion and internally rotated gait pattern compared to a control group of typically developing children? And how would the functional role of the muscle be altered if the patients walked straight?

METHODS

This follow-up study compared patients with increased femoral anteversion (n = 42, 12.8 ± 1.9 years, femoral anteversion: 39.6 ± 6.9°) to controls (n = 9, 12.0 ± 3.0 years, femoral anteversion: 18.7 ± 4.1°). Muscle forces and moment contributions were calculated using personalized musculoskeletal models. Additionally, a hypothetical scenario, in which the gait of the controls was modelled with an anteverted femoral morphology, was used to understand what would happen if the patients walked straight.

RESULTS

Gluteus medius abductive contribution was lower in patients compared to controls, despite a comparable net abduction moment around the hip. Patients presented lower muscle forces. However, if modelled to walk straight, they would require higher forces as well as a larger co-contraction of both hip internal and external rotators in the transversal plane.

SIGNIFICANCE

This study suggests that patients with increased femoral anteversion walking with an internally rotated gait pattern present lower muscle forces, but when modelled to walk straight muscle forces increase. The current results provide important information to better understand this condition and improve treatment recommendations in these patients.

3D Gait Analysis and Patient-reported Outcomes of Femoral Osteotomies for Torsional Deformity

BACKGROUND

Idiopathic torsional deformities causing pain and/or functional difficulty is an indication for a femoral derotational osteotomy (FDRO). Past studies have focused entirely on children with internal femoral torsional deformity (IFTD). This study aims to compare gait and outcomes between children with IFTD and those with external femoral torsional deformity (EFTD) after a FDRO.

METHODS

A retrospective review of all patients who underwent an FDRO between 1997 and 2020 at our institution. Data on typically developing (TD) children with no torsional deformity was used as a control group. We analyzed preoperative and postoperative standardized physical examination, 3-dimensional gait analysis, and Pediatric Outcomes Data Collection Instrument questionnaires.

RESULTS

There were 54 patients in total (IFTD=37, EFTD=17) and 20 patients in the control group. The EFTD cohort was older (IFTD=11.7, EFTD=14.7, P <0.05) and had a higher body mass index both preoperatively (IFTD=21.1 kg/m 2 , EFTD=32.1 kg/m 2 , P <0.05) and postoperatively (IFTD=20.2 kg/m 2 , EFTD=34.1 kg/m 2 , P <0.05). Preoperatively, 3-dimensional gait analysis elicited mean hip rotation in stance was more internal for IFTD cohort (10.8 degrees) and external for the EFTD cohort (-17.8 degrees) in comparison to the TD (2.4 degrees, P <0.001). Postoperatively, dynamic mean hip rotation during stance was -1.4 degrees for IFTD, whereas for EFTD, it was -5.4 degrees, which was different to the TD ( P <0.05). The IFTD group's Pediatric Outcomes Data Collection Instrument improved for transfer/basic mobility, sports/physical function, global functioning, and satisfaction with symptoms ( P <0.05). The EFTD group that only reported an improvement with the satisfaction with symptoms after surgery ( P <0.05).

CONCLUSIONS

Adolescents with surgically corrected IFTD show more improvement in gait and in patient-reported outcomes than those with surgically corrected EFTD. Children with EFTD persist in external rotation and have less satisfactory patient-reported outcomes after a FDRO in comparison those with IFTD.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Frontal plane knee moment in clinical gait analysis: A systematic review on the effect of kinematic gait changes

INTRODUCTION

The frontal plane knee moment (KAM1 and KAM2) derived from non-invasive three-dimensional gait analysis is a surrogate measure for knee joint load and of great interest in clinical and research settings. Many aspects can influence this measure either unintentionally or purposely in order to reduce the knee joint load to relieve symptoms and pain. All these aspects must be known when conducting a study or interpreting gait data for clinical decision-making.

METHODS

This systematic review was registered with PROSPERO (CRD42020187038). Pubmed and Web of Science were searched for peer-reviewed, original research articles in which unshod three-dimensional gait analysis was undertaken and KAM1 and KAM2 were included as an outcome variable. Two reviewers independently screened articles for inclusion, extracted data and performed a methodological quality assessment using Downs and Black checklist.

RESULTS

In total, 42 studies were included. Based on the independent variable investigated, these studies were divided into three groups: 1) gait modifications, 2) individual characteristics and 3) idiopathic orthopedic deformities. Among others, fast walking speeds (1) were found to increase KAM1; There were no sex-related differences (2) and genu valgum (3) reduces KAM1 and KAM2.

CONCLUSION

While consistent use of terminology and reporting of KAM is required for meta-analysis, this review indicates that gait modifications (speed, trunk lean, step width), individual characteristics (body weight, age) and idiopathic orthopedic deformities (femoral or tibial torsion, genu valgum/varum) influence KAM magnitudes during walking. These factors should be considered by researchers when designing studies (especially of longitudinal design) or by clinicians when interpreting data for surgical and therapeutic decision-making.

The Effects of Lower Extremity Rotational Malalignment on Pediatric Patient-reported Outcomes Measurement and Information System (PROMIS) Scores

BACKGROUND

There is sparse literature demonstrating the relationship between lower limb pediatric idiopathic rotational malalignment (IRM) and patient-reported outcomes measurement information system (PROMIS) scores. Our goal is to determine and quantify the amount that IRM deformities, as measured with the 3D gait analysis, affect childrens' pain interference, mobility, and peer relationship PROMIS domains. Secondary outcomes include investigating the potential relationships between IRM and various subgroups (Pediatric Outcomes Data Collection Instrument (PODCI), gender, Body Mass Index (BMI), femur Versus tibia). We also examine whether the PROMIS domains correlate with PODCI in this population.

METHODS

This study was a retrospective cohort, single institution, and consecutively recruited cases series. We identified 47 children over a 3-year period who were evaluated at the motion analysis center at our tertiary care hospital, with increased torsion of the femur or tibia. After exclusions, 25 children with IRM, documented PROMIS data and gait analysis were considered.

RESULTS

Femoral malrotation had a significant relationship with female gender ( P =0.001) and increased BMI ( P <0.001). Femoral malrotation had a correlation with PROMIS pain interference ( P =0.016), whereas tibial rotation did not achieve significance ( P =0.084). In the ANOVA regression analysis, there was a strong prediction of the PROMIS mobility domain when both malrotation and pain interference were present ( P =0.007). There were Pearson Correlations of PROMIS and PODCI domains for Mobility Versus Sports ( P =0.007) and Pain Interference Versus Comfort/Pain ( P =0.004), respectively.

CONCLUSION

The evident relationship between lower limb rotational malalignment and PROMIS scores signifies the likelihood for gait and pain disturbance. This in turn could show us that children are likely to be more debilitated and thus may benefit from timely correction. We aim to conduct this as a multicentre trial to confirm our findings.

LEVEL OF EVIDENCE

Level IV.

Increased Femoral Anteversion Does Not Lead to Increased Joint Forces During Gait in a Cohort of Adolescent Patients

Orthopedic complications were previously reported for patients with increased femoral anteversion. A more comprehensive analysis of the influence of increased femoral anteversion on joint loading in these patients is required to better understand the pathology and its clinical management. Therefore, the aim was to investigate lower-limb kinematics, joint moments and forces during gait in adolescent patients with increased, isolated femoral anteversion compared to typically developing controls. Secondly, relationships between the joint loads experienced by the patients and different morphological and kinematic features were investigated. Patients with increased femoral anteversion (n = 42, 12.8 ± 1.9 years, femoral anteversion: 39.6 ± 6.9°) were compared to typically developing controls (n = 9, 12.0 ± 3.0 years, femoral anteversion: 18.7 ± 4.1°). Hip and knee joint kinematics and kinetics were calculated using subject-specific musculoskeletal models. Differences between patients and controls in the investigated outcome variables (joint kinematics, moments, and forces) were evaluated through statistical parametric mapping with Hotelling T2 and t-tests (α = 0.05). Canonical correlation analyses (CCAs) and regression analyses were used to evaluate within the patients’ cohort the effect of different morphological and kinematic predictors on the outcome variables. Predicted compressive proximo-distal loads in both hip and knee joints were significantly reduced in patients compared to controls. A gait pattern characterized by increased knee flexion during terminal stance (KneeFlex_tSt) was significantly correlated with hip and knee forces, as well as with the resultant force exerted by the quadriceps on the patella. On the other hand, hip internal rotation and in-toeing, did not affect the loads in the joints. Based on the finding of the CCAs and linear regression analyses, patients were further divided into two subgroups based KneeFlex_tSt. Patients with excessive KneeFlex_tSt presented a significantly higher femoral anteversion than those with normal KneeFlex_tSt. Patients with excessive KneeFlex_tSt presented significantly larger quadriceps forces on the patella and a larger posteriorly-oriented shear force at the knee, compared to patients with normal KneeFlex_tSt, but both patients’ subgroups presented only limited differences in terms of joint loading compared to controls. This study showed that an altered femoral morphology does not necessarily lead to an increased risk of joint overloading, but instead patient-specific kinematics should be considered.

Subject-Specific Modeling of Femoral Torsion Influences the Prediction of Hip Loading During Gait in Asymptomatic Adults

Hip osteoarthritis may be caused by increased or abnormal intra-articular forces, which are known to be related to structural articular cartilage damage. Femoral torsional deformities have previously been correlated with hip pain and labral damage, and they may contribute to the onset of hip osteoarthritis by exacerbating the effects of existing pathoanatomies, such as cam and pincer morphologies. A comprehensive understanding of the influence of femoral morphotypes on hip joint loading requires subject-specific morphometric and biomechanical data on the movement characteristics of individuals exhibiting varying degrees of femoral torsion. The aim of this study was to evaluate hip kinematics and kinetics as well as muscle and joint loads during gait in a group of adult subjects presenting a heterogeneous range of femoral torsion by means of personalized musculoskeletal models. Thirty-seven healthy volunteers underwent a 3D gait analysis at a self-selected walking speed. Femoral torsion was evaluated with low-dosage biplanar radiography. The collected motion capture data were used as input for an inverse dynamics analysis. Personalized musculoskeletal models were created by including femoral geometries that matched each subject’s radiographically measured femoral torsion. Correlations between femoral torsion and hip kinematics and kinetics, hip contact forces (HCFs), and muscle forces were analyzed. Within the investigated cohort, higher femoral antetorsion led to significantly higher anteromedial HCFs during gait (medial during loaded stance phase and anterior during swing phase). Most of the loads during gait are transmitted through the anterior/superolateral quadrant of the acetabulum. Correlations with hip kinematics and muscle forces were also observed. Femoral antetorsion, through altered kinematic strategies and different muscle activations and forces, may therefore lead to altered joint mechanics and pose a risk for articular damage. The method proposed in this study, which accounts for both morphological and kinematic characteristics, might help in identifying in a clinical setting patients who, as a consequence of altered femoral torsional alignment, present more severe functional impairments and altered joint mechanics and are therefore at a higher risk for cartilage damage and early onset of hip osteoarthritis.

The impact of symptomatic femoral neck anteversion and tibial torsion on gait, function and participation in children and adolescents

BACKGROUND

Torsional deformities of the lower limbs in children and adolescents are a common cause of in-toeing gait and cause gait deviations. The purpose of this study was to examine the relationship of children and adolescents with suspected Idiopathic Torsional Deformities (ITD) and pain, gait function, activity and participation.

METHODS

A retrospective review of all children and adolescents who attended our Centre over a 5-year period for evaluation of the effect of ITD. All children completed three-dimensional gait analysis (3DGA), standardized physical examination, medical imaging and the Pediatric Outcomes Data Collection Instrument (PODCI). Statistical analysis was completed using two sample t-tests, Pearson's Correlation and linear regression.

RESULTS

Fifty children and adolescents, 40 females and 10 males with a mean age of 13.5 years were included. Children reported a high prevalence of pain(86%), had increased internal hip rotation(p = 0.002) and decreased external hip rotation(p < 0.001) on physical examination when compared to published normative data. Medical imaging showed a mean(SD) femoral neck anteversion (FNA) of 38°(13°) and external tibial torsion of 39°(12°). Mean(SD) PODCI score was 32(16), indicating these children are functioning below their typically developing peers. The 3DGA kinematics show deviations from typical data including hip rotation, foot progression, pelvic tilt, hip flexion and knee extension. Observed mild kinetic deviations were within typical limits. The relationship between FNA and gait parameters, FNA and PODCI and gait and PODCI were weak.

SIGNIFICANCE

These children and adolescents have altered gait and experience pain leading to impaired function and diminished participation. Therefore, ITD is not purely a cosmetic issue.

Compensatory gait deviations in patients with increased outward tibial torsion pre and post tibial derotation osteotomy

BACKGROUND

Tibial torsion describes the rotation between the proximal and distal joint axis along the shaft, which can be, as rotational deformity, pathologically increased or decreased. Some patients might increase hip internal rotation during walking to compensate increased outward tibial torsion.

RESEARCH QUESTION

The aim of this study was to assess the effect of tibial derotation osteotomy on gait deviations in patients with increased outward tibial torsion.

METHODS

Thirteen patients (13.5 ± 1.4 yrs, 22 limbs) with increased tibial torsion (CT confirmed 49.2 ± 4.8°) were analyzed pre and post tibial derotation osteotomy and compared with 17 typically developing children (TDC, 13.5 ± 2.3 yrs, 32 limbs). Kinematic and kinetic data were recorded. Subgroup analyses were performed whether patients showed compensatory hip internal rotation (Comp) or not (NoComp). Principal component (PC) analysis was used to achieve data transformation. A linear mixed model was used to estimate the main effect of PC-scores of retained PCs explaining 90% of the cumulative variance.

RESULTS

Compensatory hip internal rotation (Comp, present in 45.5% of limbs analyzed) led to a lower external foot progression angle compared to patients without compensatory hip internal rotation (NoComp). In both patient groups foot progression angle was normalized after tibial derotation osteotomy. Post-operative NoComp had normalized frontal plane joint loadings, while Comp showed an increased hip and knee adduction moment.

SIGNIFICANCE

Future studies should investigate if more time is needed for Comp to normalize gait patterns post-operative or if a pre and post-operative gait training might help. Otherwise the increased knee adduction moment might be clinically relevant due to previous studies reporting a possible association with knee osteoarthritis.

Increased femoral anteversion-related biomechanical abnormalities: lower extremity function, falling frequencies, and fatigue

BACKGROUND

Increased femoral anteversion (IFA) is defined as forwardly rotated femoral head relative to the transcondylar knee axis which may have a potential to reduce the functional quality of adolescents. Therefore, the aim of our study was to investigate the effects of IFA on lower-extremity function, falling frequency, and fatigue onset in neurologically intact children.

RESEARCH QUESTION

Does increased femoral anteversion influence lower extremity function, falling frequency and fatigue on set in healthy children?

METHODS

Sixty-five participants with increased femoral anteversion (IFA) and thirty-two healthy peers as control were included into the study. For the function, the lower extremity function form (LEFF) which is adapted from Lower Extremity Function Test used. Falling frequency and fatigue onset time were assessed by a Likert-type scale. In addition, the activities which cause frequently fall for the participants were questioned.

RESULTS

Lower extremity function was found deteriorated (p= 0.02) and falling frequency was higher (p = 0.00) in IFA than in controls. Fatigue onset time was not different between groups, although lower extremity function was strongly correlated with fatigue onset (rho = -0.537, p < 0.001). IFA children fall four times more during running (60%), three times more during fast walking (21.42%) than their healthy peers (14.28%, 7.14% respectively).

SIGNIFICANCE

IFA leads functional problems, especially in the form of high falling frequencies. According to the LEFF score, the most difficult functional parameters for these children were walking long distances, becoming tired, walking more than a mile, and standing on one spot. Also, shorter fatigue onset time may worsen the lower-extremity function secondarily. Because of the higher frequency of falling and functional problems, children with IFA may be more defenseless to injuries, especially in high-motor-skill activities such as running and soccer.