Measurement of the quadriceps (Q) angle with respect to various body parameters in young Arab population

Specific considerations in female patients with patellar instability: current concepts

Prior literature suggests that patellofemoral instability (PFI) is significantly more prevalent in women than in men. This higher prevalence is commonly attributed to anatomical differences between sexes, particularly with patellofemoral alignment. These differences encompass a higher rate of trochlear dysplasia (TD), patella alta, an increased Q angle, and soft tissue imbalances. In recent years, worse outcomes have been reported in female patients after patellofemoral stabilization surgery using medial patellofemoral ligament reconstruction (MPFLr) alone or in combination with a tibial tubercle osteotomy (TTO), for this reason an "à la carte" plan (addressing the individuals anatomical risk factors) could be more appropriate for female patients.

A Sensorized 3D-Printed Knee Test Rig for Preliminary Experimental Validation of Patellar Tracking and Contact Simulation

Experimental validation of computational simulations is important because it provides empirical evidence to verify the accuracy and reliability of the simulated results. This validation ensures that the simulation accurately represents real-world phenomena, increasing confidence in the model's predictive capabilities and its applicability to practical scenarios. The use of musculoskeletal models in orthopedic surgery allows for objective prediction of postoperative function and optimization of results for each patient. To ensure that simulations are trustworthy and can be used for predictive purposes, comparing simulation results with experimental data is crucial. Although progress has been made in obtaining 3D bone geometry and estimating contact forces, validation of these predictions has been limited due to the lack of direct in vivo measurements and the economic and ethical constraints associated with available alternatives. In this study, an existing commercial surgical training station was transformed into a sensorized test bench to replicate a knee subject to a total knee replacement. The original knee inserts of the training station were replaced with personalized 3D-printed bones incorporating their corresponding implants, and multiple sensors with their respective supports were added. The recorded movement of the patella was used in combination with the forces recorded by the pressure sensor and the load cells, to validate the results obtained from the simulation, which was performed by means of a multibody dynamics formulation implemented in a custom-developed library. The utilization of 3D-printed models and sensors facilitated cost-effective and replicable experimental validation of computational simulations, thereby advancing orthopedic surgery while circumventing ethical concerns.

Use of patellofemoral digital twins for patellar tracking and treatment prediction: comparison of 3D models and contact detection algorithms

Introduction: Poor patellar tracking can result in painful contact pressures, patella subluxation, or dislocation. The use of musculoskeletal models and simulations in orthopedic surgeries allows for objective predictions of post-treatment function, empowering clinicians to explore diverse treatment options for patients. Although a promising approach for managing knee surgeries, the high computational cost of the Finite Element Method hampers its clinical usability. In anticipation of minimal elastic deformations in the involved bodies, the exploration of the Multibody Dynamics approach emerged as a viable solution, providing a computationally efficient methodology to address clinical concerns related to the knee joint. Methods: This work, with a focus on high-performance computing, achieved the simulation of the patellofemoral joint through rigid-body multibody dynamics formulations. A comparison was made between two collision detection algorithms employed in the simulation of contact between the patellar and femoral implants: a generic mesh-to-mesh collision detection algorithm, which identifies potential collisions between bodies by checking for proximity or overlap between their discretized mesh surface elements, and an analytical contact algorithm, which uses a mathematical model to provide closed-form solutions for specific contact problems, but cannot handle arbitrary geometries. In addition, different digital twins (3D model geometries) of the femoral implant were compared. Results: Computational efficiency was considered, and histories of position, orientation, and contact force of the patella during the motion were compared with experimental measurements obtained from a sensorized 3D-printed test bench under pathological and treatment scenarios. The best results were achieved through a purely analytical contact detection algorithm, allowing for clinical usability and optimization of clinical outcomes.

Quadriceps Angle Measurement in Adolescents With Short Stature: Exploring the Relationship Between Postural Alignment and Lower Limb Mechanics

Background The quadriceps angle (Q angle) is measured as an angle formed by two lines that extend from the anterior superior iliac spine to the midpoint of the patella and from the midpoint of the patella to the tibial tuberosity. The average Q angle value for children aged between seven to 12 years was 13.1˚±3.5˚in boys and 13.7˚±4.9˚ in girls, whereas 8˚-15˚ in men and 12˚-19˚ in women. Abnormal variation in Q angle is associated with patellofemoral pain syndrome, lateral patellar malposition, dislocation, chondromalacia patella, patella alta, genu varum, etc. Methodology The present study explores the status of Q angle values among adolescents with short stature and their comparison with age and gender-matched children between 10 and 15 years of age. Results We found a statistically significant difference between the Q angle value in the control group and the male with short stature group aged 14-15 years, with a mean difference of 3.7˚. However, among females, there was a significant difference between the control group and the short-stature group aged 12-13 and 14-15 years, with a mean difference of 2.8˚ and 2.5˚, respectively. Implications Early detection and timely remedial measures, e.g., quadriceps strengthening exercises, before skeleton maturity can prevent Q angle-related misalignments and abnormalities in the limb.

Comparison and Relationship of Quadriceps Femoris Angle, Muscle Strength, and Balance in Athletes and Non-Athletes

Objective

Q-angle is an important parameter to assess quadriceps muscle's function and its effect on knee. The present study aims to investigate the potential relationships between Q-angle, muscle strength, and balance in both athlete and non-athlete populations.

Methods

Fifty-six athletes and non-athletes aged between 18 and 20 were included in this cross-sectional study. The Q-angle of each participant was measured using a universal goniometer. Muscle strength was evaluated using hand-held dynamometer, and static and dynamic balance were assessed using the one-leg stand test and Y balance test, respectively.

Results

Our findings revealed that athletes had a significantly smaller Q angle than non-athletes (p < 0.05). Furthermore, male participants had both higher muscle strength and better static balance with eyes closed than female participants (p < 0.05). Similarly, athletes had both higher muscle strength and better static balance than non-athletes (p < 0.05). Moreover, we found that the dominant limb had a significantly smaller Q angle than the non-dominant limb (p < 0.05). However, we did not observe a significant relationship between Q angle and dynamic balance (p > 0.05).

Conclusion

Our study suggests that individuals who participate in sports have lower Q angle values than those who do not participate in sports. Additionally, gender differences may exist in muscle strength and static balance. Furthermore, the Q angle was found to be lower in the non-dominant extremity compared to the dominant extremity. Finally, our study revealed a significant association between Q angle and knee muscle strength and static balance. Further research is needed to elucidate the underlying mechanisms of these relationships.

Knee skin temperature response of patients with bilateral patellofemoral syndrome before and after heat and cold stress

Patellofemoral Pain Syndrome is characterized by the presence of pain in the front area of the knee, which occurs when performing common activities such as climbing stairs, and bending the knees, among others. The objective of this research was to evaluate the detection capability of infrared thermography in patients with Patellofemoral Pain Syndrome, in the baseline state, as well as after the application of thermal stress. The investigation was conducted in 48 patients, who were subdivided into four groups (n = 12). Two subgroups were healthy patients and two with Patellofemoral Pain Syndrome. For the diagnosis of the syndrome, a manual evaluation was performed using the Zohlen test and Q angle measurement. Subsequently, cold stress was applied for 10 min to a healthy subgroup and an experimental subgroup. The remaining two subgroups were subjected to heat stress for 15 min. Thermographic images of the lower extremities were acquired at seven time points, at baseline, immediately after application of thermal stress and then every 3 min until 15 min were completed. It was observed that patients presented Patellofemoral Pain Syndrome bilaterally. After statistical analysis, it was found that there were no significant differences in baseline temperature between the groups. However, for heat stress, a higher temperature was observed in the group with Patellofemoral Pain Syndrome (p < 0.05) in the recovery period, and in the case of cold stress, only a lower temperature in the left knee immediately after the application. In conclusion, it is not possible to detect patellofemoral syndrome bilaterally in the baseline state by thermography and neither is it evident in cold stress. However, after heat stress, thermal recovery is lower for the PFPS group, so it would be susceptible to detection.

Patellofemoral Pain, Q-Angle, and Performance in Female Chinese Collegiate Soccer Players

Background and objective: Female sports injuries have been neglected by science, and few relevant studies have considered female subjects. Knee pain in female soccer players is more common than in male soccer players. The number of days of absence from training and competition has been shown to be higher in females than males. The reporting of knee pain is common in female soccer players, but whether knee pain is associated with morphological features is unclear. The Q-angle of the knee has been hypothesized to be a causal factor in knee pain. Asian females have shown higher levels of valgus than non-sporting Caucasian populations, but no data exist for female Chinese players. The aim of our study was to investigate whether there are associations between knee pain, the Q-angle of the lower limb, jump performance, play time, and perceived exertion in female Chinese collegiate soccer players. Materials and Methods: We measured the Q-angle, patellofemoral/anterior knee pain (SNAPPS questionnaire), and CMJ and SJ performance of 21 subjects (age: 20.09 ± 1.13 years, weight: 56.9 ± 6.26 kg, height: 164.24 ± 4.48 cm, and >10 years of practice) before and after a match; Borg scale and play time results were also recorded. Results: We found that our studied group had higher Q-angles in comparison to other ethnic groups reported in the literature, as well as an association of the Q-angle with the age, height, and weight of the players; however, contrary to other studies, we did not find any association between the Q-angle and knee pain, jumps, play time, or perceived exertion. Knee pain was not associated with any of the measured variables. Conclusions: Female Chinese soccer players showed higher Q-angles than players of other ethnic groups, a result that was associated with anthropometrics. The Q-angle was not found to be associated with knee pain, for which the sole determinant was body height.

The effect of quadriceps anatomical factors on patellar stability: A systematic review

PURPOSE

The aim of this systematic review was to analyse the effect of quadriceps anatomical factors on patellar stability.

METHODS

The protocol for this review was registered on PROSPERO with registration number CRD42022334265. A systematic PRISMA compliant database search was conducted. Electronic databases (MEDLINE, Global Health, MIDIRS, Embase, PsycARTICLES and APA PsycInfo), currently registered studies, conference proceedings and the reference lists of included studies were searched. A narrative synthesis provided a summary of current evidence pertaining to the effect of quadriceps anatomical factors on patellar stability.

RESULTS

A total of 9168 records were screened in the initial search. Of these, 20 articles satisfied the inclusion criteria, assessing 754 knees of 689 patients, and 69 cadaveric knees. Vastus medialis obliquus strength (VMO) affected patellar stability up to 15° of knee flexion, whereas medial retinaculum integrity did so up to 30° of knee flexion. Studies disagreed as to whether this applied to the rest of knee flexion. There is conflicting evidence regarding the effect of VMO elevation, cross-sectional area and angulation on patellar stability. The lateral retinaculum contributed to patellar stability throughout the entirety of knee flexion. Quadriceps angle altered patellar orientation during knee flexion, but not extension.

CONCLUSION

Whilst vastus medialis obliquus strength was found to be a determinant of patellar stability, there is conflicting evidence regarding the effect of VMO morphological parameters on patellar stability. The lateral retinaculum provided stability throughout the entirety of knee flexion, and the medial retinaculum did so up to 30° of flexion.

Lower-Limb Kinematic Change during Pelvis Anterior and Posterior Tilt in Double-Limb Support in Healthy Subjects with Knee Malalignment

This study aimed to investigate lower-limb kinematic changes during pelvic tilting in participants with knee malalignment. To define participants with lower-limb malalignment, the quadriceps angle (Q-angle) was used in this study. The sample population was divided into two groups in accordance with the Q-angle: the experimental group (ABQ) consisted of participants with an abnormal Q-angle greater than the normal range, and the control group (CON) consisted of participants with a normal Q-angle. All participants performed anterior and posterior pelvic tilts in double-limb support. Kinematic change in the lower limb was evaluated using a three-dimensional motion analysis system (Motion Analysis, Santa Rosa, CA, USA). The horizontal plane hip angle in the ABQ was significantly different compared with that in the CON in all positions (p < 0.05), and no significant difference was observed in the other lower-limb kinematic variables (p > 0.05). A significant correlation was identified only between the Q-angle and horizontal plane hip angle in all positions. Based on the results, the Q-angle was strongly related to the thigh, although it may not be related to malalignment with other segments during double-limb support.

Clinical Significance of the Static and Dynamic Q-angle

Q-angle represents the resultant force vector of the quadriceps and patellar tendons acting on the patella. An increased Q-angle has been considered a risk factor for many disorders and injuries. This literature review challenges the clinical value of static Q-angle and recommends a more dynamic movement evaluation for making clinical decisions. Although there are many articles about static Q-angle, few have assessed the value of dynamic Q-angle. We searched Scopus and PubMed (until September 2021) to identify and summarize English-language articles evaluating static and dynamic Q-angle, including articles for dynamic knee valgus (DKV) and frontal plane projection angle. We also used textbooks and articles from references to related articles. Although static Q-angle measurement is used systematically in clinical practice for critical clinical decisions, its interpretation and clinical translation present fundamental and intractable limitations. To date, it is acceptable that mechanisms that cause patellofemoral pain and athletic injuries have a stronger correlation with dynamic loading conditions. Dynamic Q-angle has the following three dynamic elements: frontal plane (hip adduction, knee abduction), transverse plane (hip internal rotation and tibia external rotation), and patella behavior. Measuring one out of three elements (frontal plane) illustrates only one-third of this concept. Static Q-angle lacks biomechanical meaning and utility for dynamic activities. Although DKV is accompanied by hip and tibia rotation, it remains a frontal plane measurement, which provides no information about the transverse plane and patella movement. However, given the acceptable reliability and the better differentiation capability, DKV assessment is recommended in clinical practice.

Gender-Related Aspects in Osteoarthritis Development and Progression: A Review

Osteoarthritis (OA) is a common degenerative joint disease treated mostly symptomatically before approaching its definitive treatment, joint arthroplasty. The rapidly growing prevalence of OA highlights the urgent need for a more efficient treatment strategy and boosts research into the mechanisms of OA incidence and progression. As a multifactorial disease, many aspects have been investigated as contributors to OA onset and progression. Differences in gender appear to play a role in the natural history of the disease, since female sex is known to increase the susceptibility to its development. The aim of the present review is to investigate the cues associated with gender by analyzing various hormonal, anatomical, molecular, and biomechanical parameters, as well as their differences between sexes. Our findings reveal the possible implications of gender in OA onset and progression and provide evidence for gaps in the current state of art, thus suggesting future research directions.

Analysis of Predictors Affecting Biomechanical Function of the Knee Joint and Its Relation to Anterior Knee Pain

Background: Anterior knee pain is the most common problem in the young and sporting population. Quadriceps femoris angle and condylar distance are tools to assess the bio-mechanical function of the knee joint. The aim of this research was to give comparative data of quadriceps femoris angle and condylar distance in the Indian population (sedentary/sportsperson). The study also aims to know which parameter (condylar distance/quadriceps angle) is the better predictor for knee pain in the young Indian population.

Materials and methods: This study was composed of a total of 130 individuals suffering from anterior knee pain which was divided into two categories; Sedentary and sportsperson. Each category consisted of 65 individuals. Q angle (goniometric method) and condylar distance (manual caliper) of each participant were calculated. A comparison of body parameters was done by independent t-test. Comparison between the two parameters (condylar distance and quadriceps angle) was done to know which is the better predictor of anterior knee pain.

Results: Statistically significant sexual variation (p<0.05) was observed in both quadriceps angle and condylar distance in sedentary and sportsperson groups. Females had a higher value of Q angle than males (p<0.05). The difference in quadriceps angle was statistically significant (p<0.05) between sedentary and sportsperson groups. Cohen’s kappa coefficient of Q angle was 0.72 while that of bi-condylar distance was 0.49. 

Conclusion: Q angle is a better indicator for anterior knee pain than condylar distance. Females in either category; sedentary and sportsperson, had higher Q angle in comparison to males making them more susceptible to disorders of the patellofemoral joint. Hence, encouragement and awareness are needed not only to carry out periodic screening of the susceptible population but also to emphasize its usage in clinical practice and the prognosis of the affected individual after treatment.

Determining the relationship between the quadriceps and tibiofemoral angles among adolescents

Objectives

This study aims to determine the relationship between the quadriceps angle (Q-angle) and tibiofemoral angle (TF-angle) among adolescents. We also compared the angles between both the lower limbs with respect to dominancy, measured the difference between athletic and non-athletic angles, and explored the variations of these features in different sports.

Methods

We recruited 150 adolescents aged between 12 and 18 years and classified them into two groups; group A (athletic group), including four subgroups of players of different sports, and group B (non-athletic group). We measured the Q-angle and TF-angle via computerized photogrammetry.

Results

This study showed a strong and statistically significant relationship between Q-angle and TF-angle (p < 0.05). Similarly, we found a statistically significant difference in the Q-angle and TF-angle between both the lower limbs concerning dominance. Lastly, we identified a significant difference between the athletic and non-athletic groups. However, there was no difference among players of different sports (p > 0.05).

Conclusion

Our study showed a strong relationship between the Q-angle and the TF-angle. The Q-angle and the TF-angle should be measured bilaterally and the nature of sports should also be considered.

Risk factors for progression to total knee arthroplasty within two years of presentation for knee osteoarthritis

INTRODUCTION

Knee osteoarthritis (OA) is a leading cause of disability and functional limitations in aging adults. Total knee arthroplasty (TKA) is the gold standard treatment of this condition. The purpose of this study is to evaluate which patient characteristics are associated with proceeding to TKA.

METHODS

Retrospective review of patients with knee osteoarthritis at a single institution was conducted. Demographic, radiographic and clinical patient characteristics were analyzed. The primary outcome measure was whether patients underwent TKA over the study time-period. Univariate comparisons between patients not undergoing surgery and those undergoing TKA were performed. Multivariate logistic regression was performed to evaluate risk factors for undergoing TKA.

RESULTS

Two hundred seven patients were included in the study. One hundred eighty seven patients (90.3%) did not undergo surgery, while 20 (9.7%) underwent TKA. No statistically significant differences in demographics were observed between patients who underwent TKA and those who did not. On multivariate analysis, patients with Kellgren Lawrence grade 4 OA (OR: 20.793, p = 0.009) and varus alignment (OR: 13.044, p = 0.040) were at significantly increased risk of undergoing TKA. Using only these two variables, the area under the curve for predicting which patients would undergo TKA was 0.846, indicating excellent discrimination.

CONCLUSION

In patients diagnosed with knee OA, Kellgren Lawrence grade 4 classification and varus knee alignment are significant risk factors for undergoing TKA, and are associated with a decreased time from initial presentation to surgery. These findings may be used to counsel patients, aid triage decisions, and inform the development of future predictive models.