Imaging Approaches for Accurate Determination of the Quadriceps Angle

Effects of Rhythm Step Training on Foot and Lower Limb Balance in Children and Adolescents with Flat Feet: A Radiographic Analysis

Background and Objectives: Owing to the recent reports regarding the efficacy of rhythm step training (RST) in lower limb muscle development and motor skill enhancement, this study aimed to evaluate the effects of RST on foot and lower limb balance in children and adolescents diagnosed with flat feet using radiographic analysis. Materials and Methods: A total of 160 children and adolescents diagnosed with flat feet from a hospital in Seoul were randomly assigned to the general flat feet training (GFFT) (n = 80) or RST (n = 80) group. Patients in both groups exercised for 50 min once a week for 12 weeks. Key variables, such as quadriceps angle (Q-angle), calcaneal pitch angle (CPA), calcaneal-first metatarsal angle (CFMA), and navicular-cuboid overlap ratio (OR) were measured before and after the intervention. Results: Significant improvements in Q-angle (p < 0.001), CPA (p < 0.001), CFMA (p < 0.001), and navicular-cuboid OR (p < 0.001) were observed in the RST group compared to the GFFT group. RST was found to be more effective in normalizing the biomechanical function of the calcaneus and improving lower limb function. Conclusions: RST significantly enhances foot and lower limb balance in children and adolescents with flat feet, suggesting its potential use as an effective intervention for this population. The study did not specifically analyze the effects of various components of rhythm training, such as music, exercise intensity, and frequency, on the outcomes. Further research is needed to determine how each of these elements individually influences the results.

Radiological Verification for the Suitability of Using the Quadriceps Angle to Represent Orientation of the Quadriceps Femoris

OBJECTIVES

The orientation of the quadriceps femoris can be represented by the quadriceps angle (Q-angle) has not yet been approved because of the high incidence of patellar instability. In this study, the correlations among components of the quadriceps femoris and the Q-angle using the plain radiographic technique were assessed. This retrospective study aims to use the radiographic technique to clarify these doubts from anatomic viewpoints.

METHODS

One hundred consecutive young adult patients (50 men and 50 women; aged, 34 ± 5 and 33 ± 6 years, respectively) who sustained chronic unilateral lower extremity injuries (unilateral femoral, tibial nonunions or malunions) were enrolled. The contralateral intact lower extremity was used for the study. The full-length standing scanogram (FLSS) was used to evaluate the rectus Q-angle (R-Q angle), vastus Q-angle (V-Q angle), and clinical Q-angle (C-Q angle; i.e., known as the Q-angle). The three Q-angles were compared statistically. The Mann-Whitney U test and the Kruskal-Wallis test were used for comparison among groups. The Spearman rank correlation coefficient was used to evaluate the degree of relationship between two groups.

RESULTS

The C-Q angle or the V-Q angle was statistically different from the R-Q angle (p < 0.001). The C-Q angle between sexes was not different (p = 0.25). High correlation occurred among the C-Q angle, the R-Q angle, and the V-Q angles (correlation coefficient, 0.886-0.979). The multiple linear regression revealed of C-Q angle = 0.72; R-Q angle, p < 0.001 + 0.21; and V-Q angle, (p = 0.009) + 2.61° in 100 patients.

CONCLUSION

Orientation of the quadriceps femoris can be represented by the Q-angle. Compared to the rectus femoris, the three vastus muscles of the quadriceps femoris are more correlated to the Q-angle.

Challenging the assumption of uniformity in patellar tendon structure: Regional patellar tendon morphology and mechanical properties in vivo

Patellar tendons are assumed to be uniform in morphology and mechanical properties despite a higher prevalence of tendinopathies observed in the medial region. The purpose of this study was to compare the thickness, length, viscosity, and shear modulus of the medial, central, and lateral regions of healthy patellar tendons of young males and females in vivo. B-mode ultrasound and continuous shear wave elastography were performed on 35 patellar tendons (17 females, 18 males) over three regions of interest. A linear mixed-effects model (α = 0.05) was used to determine differences between the three regions and sexes followed by pairwise comparisons for significant findings. The lateral region (mean [95% confidence interval] = 0.34 [0.31-0.37] cm) was thinner compared with the medial (0.41 [0.39-0.44] cm, p < 0.001), and central (0.41 [0.39-0.44] cm, p < 0.001) regions regardless of sex. Viscosity was lower in the lateral (19.8 [16.9-22.7] Pa-s) versus medial region (27.4 [24.7-30.2] Pa-s, p = 0.001). Length had a region-by-sex interaction (p = 0.003) characterized by a longer lateral (4.83 [4.54-5.13] cm) versus medial (4.42 [4.12-4.72] cm) region in males (p < 0.001), but not females (p = 0.992). Shear modulus was uniform between regions and sexes. The thinner, and less viscous lateral patellar tendon may reflect the lower load the tendon experiences explaining the differences in regional prevalence of developing tendon pathology. Statement of Clinical Significance: Healthy patellar tendons are not uniform in morphology or mechanical properties. Considering regional tendon properties may help guide targeted interventions for patellar tendon pathologies.

Patellar malalignment: A common disorder associated with knee pain

Pain-associated knee joint disorders are common in daily life. Practically, knee pain should be divided into the origin from the isolated tibiofemoral (TF), isolated patellofemoral (PF) joint, or a combination thereof. The TF joint controls the actions of level walking, while the PF joint controls knee flexion-extension. Owing to its sufficient inherent stability, non-traumatic disorders of the isolated TF joint in young individuals are uncommon. In contrast, because of its insufficient inherent stability, non-traumatic disorders of the isolated PF joint are common in young individuals. Patellar malalignment (PM) associated with knee pain is common in all age groups, and the most common predisposing factor is imbalanced peripatellar soft-tissue tension. The outward forces acting on the patella are caused by pulling from the quadriceps femoris during knee flexion to extension (manifested by the quadriceps angle [Q-angle]), and sliding backward of the iliotibial band (ITB) during knee extension to flexion. Once the muscle power of the vastus medialis (especially the vastus medialis obliquus [VMO]) decreases, which lowers the counteracting effect against outward forces, the patella displaces or rotates laterally. The reduced contact surface between the patella and the femoral condyle significantly increases the compressive pressure and injures the articular cartilage. Subsequently, progressive PF degeneration occurs. Although other factors may also cause PM, they are relatively uncommon. In principle, nonsurgical treatment of PM should be considered first, while surgical treatment should follow established indications. Some nonsurgical techniques are currently widely used that feature high satisfaction rates. Surgical techniques are continuously being developed, and their success rates have gradually improved. This study aimed to review the current literature for relevant studies and report related publications of the author's institution to emphasize the universality and importance of PM management. Conceptually, simply focusing on problems of the TF joint cannot treat all knee disorders.

A novel limb-salvage reconstruction strategy with a custom hemipelvic endoprosthesis and preserved femoral head following the resection of periacetabular tumors: A preliminary study

The treatment of periacetabular malignancy frequently challenges surgeons. To simplify the surgical procedure, we performed a novel reconstruction strategy preserving the femoral head for patients with periacetabular malignancies. We retrospectively reviewed 14 patients who underwent total en bloc resection of a periacetabular tumor and reconstruction of the hip joint with an individualized hemipelvic endoprosthesis and remaining femoral head from July 2015 to January 2019 at our center. Regions of pelvic resection: region II-4 (28.6%), region I + II-5 (35.7%), region II + III-2 (14.3%) and region I + II + III-3 (21.4%). The oncological outcomes were that 13 patients survived without disease and one patient survived with lung metastasis. None of the patients experienced local recurrence (range: 20-62 months; mean: 32 months). The incidence of postoperative complications was 35.7%, including delayed wound healing and deep venous thrombosis. No prosthesis-related complications occurred until the last follow-up in this study (range: 20-62 months; mean: 32 months). The mean Musculoskeletal Tumor Society functional outcome score was 23.2. The mean Toronto Extremity Salvage Score of the patients was 75.7 points, with a mean limb discrepancy of 1.51 cm (range: 0.5-3.2 cm). Reconstruction with preservation of the femoral head showed acceptable early functional and oncological outcomes, and it had an acceptable complication rate.

Impact of parity on biomechanical risk factors for knee OA initiation

BACKGROUND

Women are twice as likely as men to develop knee osteoarthritis (OA), and with it experience greater losses of physical function and disability. A change in the mechanical environment of the joint is a key initiating factor for knee OA. Differences in morphology, joint injury risk, and hormonal shifts in mid-life are often considered factors which increase OA risk for women. Pregnancy, a time of significant hormonal, morphological, and biomechanical change, has received comparably less attention. If morphological and biomechanical changes persist postpartum, this could increase OA risk for parous (childbearing) women.

RESEARCH QUESTION

Are lower limb gait mechanics different between healthy nulliparous (non-childbearing) and parous (childbearing) women?

METHODS

Twenty-eight self-reported not pregnant female participants (14 parous, 14 nulliparous) were recruited for the study. Nulliparous participants had never given birth to a child. Parous participants had given birth to at least one full-term infant (37-42 weeks) without complications between one to five years before data collection. Motion capture of participants' preferred, fast, and set (1.4 m/s) walking speeds was conducted. Repeated measures ANOVA were performed to test for significant group differences in joint kinematics and kinetics.

RESULTS

There was a significant main effect of group indicating a larger knee flexion angle at toe off (p = 0.0002), smaller knee extension moment at heel strike (p = 0.0006), smaller first peak knee flexion moment (p = 0.040), and smaller peak hip adduction moment for the parous group compared to the nulliparous group (p = 0.003). Static Q-angle did not differ between groups.

SIGNIFICANCE

Alteration in mechanics from the habitual loading pattern are thought to increase risk of OA. Smaller knee moments in post-partum women could alter the mechanical stimulus to cartilage, and should be investigated in conjunction with cartilage health measures to determine the link with OA initiation.