Relationships among foot position, lower limb alignment, and knee adduction moment in patients with degenerative knee osteoarthritis

Relationship between radiographic measurements and knee adduction moment using 3D gait analysis

BACKGROUND

Radiographic factors estimate the state of the static knee joint, and it is questionable how well these parameters reflect the dynamic knee condition. The external knee adduction moment (KAM) during gait is known to be a kinetic variable contributing to osteoarthritis progression. This study aims to investigate the effects of static radiographic parameters on the dynamic KAM during gait.

METHODS

Overall, 123 patients (mean age, 65.7 years; standard deviation, 8.1 years; 34 men and 89 women) were included. Seven radiographic parameters including the mechanical tibiofemoral angle (mTFA), Kellgren-Lawrence grade, and ankle joint line orientation (AJLO) were measured on radiographs, and the maximum KAM and KAM-time integral in the stance phase were obtained using three-dimensional gait analysis. The correlation and multiple regression analyses were performed for identifying significant radiographic measurements associated with the KAM.

RESULTS

Most of the radiographic measurements correlated with the maximum KAM and KAM-time integral. As a result of multiple regression analysis, the mTFA (p < 0.001) and AJLO (p = 0.003) were identified as significant factors associated with the KAM-time integral (R² = 0.450); the mTFA (p < 0.001) and AJLO (p = 0.003) were identified as a significant factor associated with the maximum KAM (R² = 0.352) in multiple regression analysis. The discriminant validity of KAM was highest at varus 5.7 degree of the mTFA and 7.5 degree of the AJLO.

SIGNIFICANCE

The mTFA and AJLO were significantly associated with the KAM. However, to be used as a surgical indication for corrective osteotomy, a longitudinal study is needed to validate whether the mTFA and AJLO values directly cause osteoarthritis progression as we have suggested.

LEVEL OF EVIDENCE

III.

Increased external rotation of the osteoarthritic knee joint according to the genu varum deformity

PURPOSE

To evaluate the rotational profile of the lower extremity using computed tomography (CT) in accordance with the degree of varus deformity in medial condyle-affected knee joint osteoarthritis (OA).

METHODS

This retrospective study included 1036 patients (872 lower extremities) with end-stage knee OA. The coronal alignment of the lower extremity was measured using standing anteroposterior radiography. The CT parameters of femoral anteversion and tibial torsion were assessed in relation to the knee joint. The axes were the femoral neck axis; the distal femoral axis, which was composed of the anterior trochlear axis, the clinical transepicondylar axis, and the posterior condylar axis; the axis of the proximal tibial condyles; and the bimalleolar axis.

RESULTS

There was a tendency for increased external rotation of the knee joint parameters in relation to the hip and ankle joints as varus deformity of the lower extremity increased. The relative external rotational deformity of the knee joint in relation to the hip joint had a positive value with a good correlation. The relative external rotational deformity of the knee joint in relation to the ankle joint also demonstrated a positive value with a good correlation.

CONCLUSION

The distal femur and proximal tibia (knee joint) tended to rotate externally in relation to the hip and ankle joint, respectively, as the degree of varus deformity increased. This study identified the relationship between lower extremity varus deformity and rotational deformity of knee joints with OA.

LEVEL OF EVIDENCE

III.

Gait Analysis after Total Knee Arthroplasty Assisted by 3D-Printed Personalized Guide

Background

With the development of three-dimensional printing (3DP) technology, the patient-specific instrumentation (PSI) has been widely applied in total knee arthroplasty (TKA). The purpose of this study was to compare the gait parameters of patients with 3DP personalized guide-assisted and standard TKA.

Methods

Retrospective analysis of the advanced knee OA cases in our hospital between June 2017 and June 2018 was conducted. 30 cases received 3DP personalized guide-assisted TKA (group A), and 60 patients who underwent standard TKA during the same period were in group B and group C according to the computed tomography (CT) measurement results, each with 30 cases. Hip–knee–ankle angle (HKA), patella transverse axis-femoral transepicondylar axis angle (PFA), and gait parameters were statistically analyzed. The function was assessed by Hospital for Specific Surgery (HSS) and Knee Society Score (KSS).

Results

The mean follow-up period was 12.3 months in the three groups. The knee max flexion angle at the swing phase of group A was larger than group B and group C (P < 0.05), there was no statistically significant difference in other gait parameters. The mean PFA of group A was smaller than that of group B and group C (P < 0.05). While, the HKA, HSS, and KSS scores of three groups showed no significant difference.

Conclusion

3DP personalized guide technology could improve the gait parameters after surgery, specifically reflected in the knee max flexion angle at the swing phase. It could also assist in the reconstruction of more accurate patellar tracking and rotational alignment in TKA, avoiding the occurrence of insufficient or excessive extorsion.

Structural Characteristics Associated With Radiographic Severity of First Metatarsophalangeal Joint Osteoarthritis

OBJECTIVE

To determine whether foot structure varies according to the presence and radiographic severity of first metatarsophalangeal (MTP) joint osteoarthritis (OA).

METHODS

Weight-bearing dorsiplantar and lateral radiographs were obtained for the symptomatic foot of 185 participants (105 women, ages 22-85 years) with clinically diagnosed first MTP joint OA. A validated atlas was used to classify participants as having radiographic first MTP joint OA and to stratify into 3 categories of severity (none/mild, moderate, severe). Bone length and width and angular measures of the forefoot and medial arch were performed on radiographs, and differences between categories were compared using univariate general linear models, adjusting for confounders.

RESULTS

A total of 150 participants were categorized as having radiographic first MTP joint OA, and participants were further stratified into none/mild (n = 35), moderate (n = 69), or severe (n = 81) OA categories. Participants with radiographically defined first MTP joint OA displayed a greater hallux abductus interphalangeal angle. Greater radiographic severity of first MTP joint OA was associated with a larger hallux abductus interphalangeal angle, a wider first metatarsal and proximal phalanx, and a smaller intermetatarsal angle. No differences in medial arch measurements were observed between the categories.

CONCLUSION

First ray alignment and morphology differed according to the presence and severity of first MTP joint OA. Prospective studies are required to determine whether the observed differences are a cause or consequence of OA.

The effect of extra-osseous talotarsal stabilization (EOTTS) to reduce medial knee compartment forces - An in vivo study

Background

Excessive hindfoot pronation, talotarsal joint (TTJ) instability, has been attributed to an increase in medial knee compartment pathology. Advocacy for hindfoot realignment has been the subject of research. An internal solution for TTJ instability, extra-osseous talotarsal stabilization (EOTTS), exists but its effect on knee forces is unknown. This is the first study to measure the in vivo forces acting within the medial knee compartment before and after EOTTS. We hypothesized that following EOTTS there should be a reduction of force acting on the medial knee compartment.

Methods

10 fresh frozen cadaver lower extremities exhibiting clinical and radiographic evidence of TTJ instability were evaluated. The proximal femur segment was mounted to a mechanical testing unit. Pressure sensors were placed within the medial knee compartment. A force of 1000 newtons was then applied, and the femur was internally rotated 10 degrees. Measurements were recorded before and after the insertion of a type II EOTTS stent.

Results

Pre-EOTTS resulted in an average of 842 ± 247N acting within the medial knee joint compartment. These forces then decreased to an average of 565 ± 260N (<0.05) following EOTTS, representing an average reduction of force by 32.8%.

Conclusion

EOTTS has been shown to decrease the in vivo forces action within the medial knee compartment. This helps to further illustrate the importance of realigning and stabilizing the hindfoot for the prevention and treatment of chronic knee pain.

The relationship between gait and functional outcomes in patients treated with circular external fixation for malunited tibial fractures

BACKGROUND

Lower extremity fractures have a profound negative effect on a patient's gait and outcomes. Correction of deformity, and with it normalization of objective gait parameters, may result in better subjective and objective functional outcomes in patients treated with circular external fixation for malunited tibial fractures.

AIM

The purpose of this study was to investigate the relationships between gait parameters, patient reported outcome measures (PROMs), and health related quality of life measures in patients treated with circular external fixation for the correction of deformity related to tibial malunions.

METHODS

This retrospective study included patients with posttraumatic tibial deformities, aged 14-65, with a minimum follow-up of 24 months following deformity correction. Patients with congenital deformities, head injuries, spinal cord injury, neurological disorders, or contralateral lower limb amputation were excluded. Functional outcomes were assessed by the Foot Function Index (FFI); Short Form 12 (SF-12); the EQ 5D; and the ASAMI score. Gait analysis was performed using Dartfish® and the Edinburgh Visual Gait Score (EVGS). The relationships between the EVGS and functional outcome scores were analyzed using Pearsons' moment correlations with Bonferroni corrections.

RESULTS

Eleven patients with a mean age of 42 (range 23-57) were analyzed. The mean EVGS was 2.6 ± 2.1, the mean FFI 29.6 ± 33.4, the mean EQ5 Index Value 0.7 ± 0.2, the mean EQ5 VAS 85.4 ± 19.5, the SF12 mean Physical Component Score (PCS) 46.7 ± 11.1, and the mean Mental Component Score (MCS) 55.2 ± 7.5. The following relationships were strong and significant: EVGS and FFI (r = 0.7; P = 0.02), EVGS and PCS (r = -0.82; P = 0.02), and FFI and EQ5 (r = -0.79, P = 0.05).

SIGNIFICANCE

The results of this study suggest that correction of deformity with realignment and restoration of normal anatomy was associated with improved functional outcomes and physical well-being. Patient reported quality of life is strongly associated with patient perceived functional outcome, but not with objective gait parameters.

Correlation between Foot Arch Index and the Intensity of Foot, Knee, and Lower Back Pain among Pregnant Women in a South-Eastern Nigerian Community

OBJECTIVES

The aim of this study was to assess the arch height index of pregnant women and its correlation with foot pain, anterior knee pain, and lower back pain.

SUBJECTS AND METHODS

Two hundred and fifteen consenting pregnant women participated in this cross-sectional study. The arch height index was assessed from their foot prints, while pain intensity was rated on a numerical rating scale. Data were summarized with descriptive statistics and the Pearson correlation was used to determine correlations between the variables at p < 0.05.

RESULTS

Of the 215 pregnant women, 123 (57.2%) and 127 (59.9%) had low arch heights on the right and left feet, respectively, and the mean arch height indices were 0.27 ± 0.71 for the right foot and 0.28 ± 0.07 for the left foot. The prevalence of foot, knee, and lower back pain was 65 (30.2%), 43 (20.0%), and 93 (43.3%), respectively. The Pearson correlation analysis did not reveal any significant relationship (p > 0.05) between foot pain and each of the right (r = -0.010, p = 0.886) and left (r = 0.004, p = 0.955) arch indices as well as between knee pain and each of the right (r = 0.042, p = 0.536) and left (r = 0.045, p = 0.515) arch indices. A similar trend was observed for the lower back, which also did not show any significant relationship to each of the right (r = 0.026, p = 0.703) and left (r = 0.097, p = 0.157) arch indices.

CONCLUSION

The study participants had a high prevalence of low foot arches, indicating pes planus. Lower back pain was more common than foot and knee pain. The foot arch heights did not show any relationships between the intensities of foot, anterior knee, and lower back pain.

Effects of muscle strength asymmetry between left and right on isokinetic strength of the knee and ankle joints depending on athletic performance level

[Purpose] The aim of this study was to collect basic data on the effect of asymmetry on the muscle strength of the left and right knee and ankle joints of soccer players at varying athletic performance levels, to guide the development of improved exercise programs. [Subjects and Methods] Forty-nine soccer players at three athletic performance levels participated: 15 professional, 16 amateur, and 18 college. Knee extensor and flexor strength were measured at 60°/sec and 180°/sec, and ankle plantar flexor and dorsiflexor strength were measured at 30°/sec and at 120°/sec. Variables were analyzed by one-way ANOVA. [Results] College soccer players showed greater muscle strength at 60°/sec and 180°/sec in the knee extension muscles of both the right and the left sides, lower muscle strength at 30°/sec and 120°/sec in the dorsiflexor of the right ankle, and similar levels of asymmetry between left and right. The maximum muscle strength on the same side significantly differed in the right ankle joint, with asymmetry between left and right at 30°/sec and 120°/sec. [Conclusion] These findings suggest that muscle strength asymmetry in the ankle joint may lead to counterbalancing muscle strengthening of the knee joint to maintain the center of body mass.

Biomechanical effects of lateral and medial wedge insoles on unilateral weight bearing

[Purpose] Lateral wedge insoles reduce the peak external knee adduction moment and are advocated for patients with knee osteoarthritis. However, some patients demonstrate adverse biomechanical effects with treatment. In this study, we examined the immediate effects of lateral and medial wedge insoles under unilateral weight bearing. [Subjects and Methods] Thirty healthy young adults participated in this study. The subjects were assessed by using the foot posture index, and were divided into three groups: normal foot, pronated foot, and supinated foot groups. The knee adduction moment and knee-ground reaction force lever arm under the studied conditions were measured by using a three-dimensional motion capture system and force plates. [Results] In the normal and pronated groups, the change in knee adduction moment significantly decreased under the lateral wedge insole condition compared with the medial wedge insole condition. In the normal group, the change in the knee-ground reaction force lever arm also significantly decreased under the lateral wedge insole condition than under the medial wedge insole condition. [Conclusion] Lateral wedge insoles significantly reduced the knee adduction moment and knee-ground reaction force lever arm during unilateral weight bearing in subjects with normal feet, and the biomechanical effects varied according to individual foot alignment.

Correlation between Quadriceps Endurance and Adduction Moment in Medial Knee Osteoarthritis

It is not clear whether the strength or endurance of thigh muscles (quadriceps and hamstring) is positively or negatively correlated with the adduction moment of osteoarthritic knees. This study therefore assessed the relationships between the strength and endurance of the quadriceps and hamstring muscles and adduction moment in osteoarthritic knees and evaluated predictors of the adduction moment. The study cohort comprised 35 patients with unilateral medial osteoarthritis and varus deformity who were candidates for open wedge osteotomy. The maximal torque (60°/sec) and total work (180°/sec) of the quadriceps and hamstring muscles and knee adduction moment were evaluated using an isokinetic testing device and gait analysis system. The total work of the quadriceps (r = 0.429, P = 0.037) and hamstring (r = 0.426, P = 0.045) muscles at 180°/sec each correlated with knee adduction moment. Preoperative varus deformity was positively correlated with adduction moment (r = 0.421, P = 0.041). Multiple linear regression analysis showed that quadriceps endurance at 180°/sec was the only factor independently associated with adduction moment (β = 0.790, P = 0.032). The adduction moment of osteoarthritic knees correlated with the endurance, but not the strength, of the quadriceps muscle. However, knee adduction moment did not correlate with the strength or endurance of the hamstring muscle.