Orthopedic University Hospital Friedrichsheim gGmbH

Frankfurt am Main, Germany

Orthopedic University Hospital Friedrichsheim gGmbH

Frankfurt am Main, Germany
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PubMed | TU Ilmenau, Aerpah Clinic Esslingen Kennenburg, Goethe University Frankfurt, Frankfurt University of Applied Sciences and 2 more.
Type: Journal Article | Journal: Medical engineering & physics | Year: 2016

This paper introduces a new approach for computing lower extremity muscle forces by incorporating equations that consider bone structure and prevention of bending by load reduction into existing optimization algorithms. Lower extremity muscle and joint forces, during normal gait, were calculated and compared using two different optimization approaches. We added constraint equations that prevent femoral bending loads to an existing approach that considers minimal total muscular force. Gait parameters such as kinematics, ground reaction forces, and surface electromyographic activation patterns were examined using standardized gait analysis. A subject-specific anatomic model of the lower extremities, obtained from magnetic resonance images of a healthy male, was used for the simulations. Finite element analysis was used to calculate femoral loads. The conventional method of calculating muscle forces leads to higher rates of femoral bending and structural stress than the new approach. Adding equations with structural subject-specific parameters in our new approach resulted in reduced femoral stress patterns. These findings show that our new approach improves the accuracy of femoral stress and strain simulations. Structural overloads caused by bending can be avoided during inverse calculation of muscle forces.

Kostuj T.,Orthopedic University Hospital Friedrichsheim gGmbH | Kostuj T.,Witten/Herdecke University | Streit R.,Orthopedic University Hospital Friedrichsheim gGmbH | Baums M.H.,Orthopedic University Hospital Friedrichsheim gGmbH | And 3 more authors.
Journal of Arthroplasty | Year: 2015

Use of mega-prostheses is a common option for the treatment of patients with malignant tumors as well as in patients with large osseous defects at the time of revision surgery. No studies have compared the two groups to determine whether there is a relative difference in clinical outcomes. We performed a midterm-outcome-study to evaluate our results in these two patient populations. Deep infection was found more often in our revision group (29.5% vs. 9.1%), however no significant differences in WOMAC-results could be found between the two groups. Surgeons should recognize the high complication rate as well as the differences in results using mega-prostheses in these two distinct groups of patients. © 2015 Elsevier Inc.

PubMed | Frankfurt University of Applied Sciences, Goethe University Frankfurt and Orthopedic University Hospital Friedrichsheim gGmbH
Type: | Journal: Gait & posture | Year: 2016

The objective of this study was to test if patients with unilateral hip osteoarthritis (OA) show greater muscle activity asymmetry between their affected and non-affected limbs than healthy controls between their left and right limbs. Seventeen patients with unilateral hip OA (7 females, 10 males) and 17 age-matched healthy controls (7 females, 10 males) participated in this study. Both groups performed instrumented gait analysis at comparable speeds. Muscle activity was recorded simultaneously for the tibialis anterior (TA), gastrocnemius medialis (GM), vastus lateralis (VL), semitendinosus (ST), tensor fasciae latae (TFL), and gluteus medius (GLM) muscles. In hip OA patients, EMG data showed greater activity of the TA muscle in the non-affected limb, and greater TFL muscle activity in the affected limb. Compared to healthy controls, greater asymmetries between paired limbs were observed for the TA and GM muscles. Finally, the TFL muscle of the affected limb contributed more to the total limb muscle activity than did the non-affected limb. The observed alterations in TA and GM muscle activity in hip OA patients may be due to the greater peak braking and peak vertical forces measured in the non-affected limb. Contrary to this, greater TLF muscle activity of the affected limb indicates the demands put on stabilizing the hip during stance phase. Further studies are necessary to test whether leg length discrepancy affects muscle activation alterations between the affected and non-affected limb in unilateral hip OA patients.

PubMed | Frankfurt University of Applied Sciences, Goethe University Frankfurt and Orthopedic University Hospital Friedrichsheim gGmbH
Type: | Journal: Journal of orthopaedic research : official publication of the Orthopaedic Research Society | Year: 2016

In order to reduce pain caused by the affected hip joint, unilateral hip osteoarthritis patients (HOAP) adopt characteristic gait patterns. However, it is unknown if the knee and hip joint loading in the non-affected (limb

Stief F.,Orthopedic University Hospital Friedrichsheim gGmbH | Bohm H.,Orthopedic Hospital for Children | Ebert C.,Goethe University Frankfurt | Doderlein L.,Orthopedic Hospital for Children | Meurer A.,Orthopedic University Hospital Friedrichsheim gGmbH
Gait and Posture | Year: 2014

Ipsilateral trunk lean toward the affected stance limb has been identified as a compensatory mechanism to unload the hip joint. However, this altered gait pattern increases the lever arm around the knee joint by shifting the ground reaction vector more lateral to the knee joint center, which could be sufficient to deform the lateral compartment of the knee. The purpose of the present study was to show the effect of ipsilateral trunk lean on hip and knee joint moments in the frontal plane in 132 young patients with different orthopedic diagnosis. Linear correlations between ipsilateral trunk lean and the external knee and/or hip adduction moment were detected for patients with Legg-Calvé-Perthes disease (LCPD), arthrogryposis multiplex congenita, myelomeningocele, and unilateral cerebral palsy (CP). In contrast, children with bilateral CP did not show such a relationship due to an increased internal foot placement. In comparison to the hip joint, the effect of ipsilateral trunk lean in patients with LCPD is obviously more pronounced in the knee joint. The valgus thrust of the knee could initiate degenerative changes by placing altered loads on regions of the articular cartilage that were previously conditioned for different load levels. The results suggest that the ipsilateral trunk lean should not be considered and recommended as unloading mechanism for the hip joint on its own but also as a potential increased joint loading of the lateral knee compartment. Therefore, an acceptable therapy concept for limping patients should aim for an inconspicuous gait pattern with a reduced trunk movement. © 2013 Elsevier B.V.

Stief F.,Orthopedic Hospital for Children | Stief F.,Orthopedic University Hospital Friedrichsheim gGmbH | Bohm H.,Orthopedic University Hospital Friedrichsheim gGmbH | Michel K.,University of Bern | And 2 more authors.
Journal of Applied Biomechanics | Year: 2013

The standard Plug-in-Gait (PiG) protocol used in three-dimensional gait analysis is prone to errors arising from inconsistent anatomical landmark identification and knee axis malalignment. The purpose of this study was to estimate the reliability and accuracy of a custom made lower body protocol (MA) compared with the PiG protocol. Twenty-five subjects volunteered to evaluate the intertrial reliability. In addition, intersession reliability was examined in 10 participants. An indirect indicator of accuracy according to the knee varus/valgus and flexion/extension range of motion (ROM) was used. Regarding frontal plane knee angles and moments as well as transverse plane motions in the knee and hip joint, the intersession errors were lower for the MA compared with the standard approach. In reference to the knee joint angle cross-talk, the MA produced 4.7̊ more knee flexion/extension ROM and resulted in 6.5̊ less knee varus/valgus ROM in the frontal plane. Therefore, the MA tested in this study produced a more accurate and reliable knee joint axis compared with the PiG protocol. These results are especially important for measuring frontal and transverse plane gait parameters. © 2013 Human Kinetics, Inc.

Stief F.,Orthopedic University Hospital Friedrichsheim gGmbH | Bohm H.,Orthopedic Hospital for Children | Dussa C.U.,Orthopedic Hospital for Children | Multerer C.,Orthopedic Hospital for Children | And 3 more authors.
Knee | Year: 2014

Background: Varus knee alignment has been identified as a risk factor for the progression of medial knee osteoarthritis (OA). This study tested the hypothesis that not only frontal plane kinematics and kinetics but also transverse plane lower extremity mechanics during gait are affected by varus malalignment of the knee. Methods: Eighteen, otherwise healthy children and adolescents with varus malalignment of the knee were studied to examine the association between static varus malalignment and functional gait parameters. Kinematic data were collected using a Vicon motion capture system (Vicon Motion Systems, Oxford, UK). Two AMTI force plates (Advanced Mechanical Technology, Inc., Watertown, MA, USA) were used to collect kinetic data. Results: The results indicated that changes in transverse plane mechanics occur concomitantly with changes in knee malalignment in the frontal plane. A mechanical consequence of varus knee malalignment is obviously an increased endorotation of the foot (internal foot placement) and an increased internal knee rotation (tibia rotation) during stance phase. The linear correlation between the maximum external knee adduction moment in terminal stance and the internal knee rotation in terminal stance ( r= 0.823, p<. 0.001) shows that this transverse plane gait mechanics is directly in conjunction with intrinsic compressive load on the medial compartment during gait. Conclusions: Understanding factors that influence dynamic knee joint loading in healthy, varus malaligned knees may help us to identify risk factors that lead to OA. Thus, three-dimensional gait analysis could be used for clinical prognoses regarding the onset or progression of medial knee OA. © 2014 Elsevier B.V.

Stief F.,Orthopedic Hospital for Children | Stief F.,Orthopedic University Hospital Friedrichsheim gGmbH | Bohm H.,Orthopedic Hospital for Children | Schwirtz A.,TU Munich | And 2 more authors.
Gait and Posture | Year: 2011

Three-dimensional gait analysis is a diagnostic tool that can be used to gain a better understanding of the relationship between joint loading and the onset or progression of articular cartilage degeneration in subjects with varus malalignment. The purpose of the present study was to investigate knee and hip joint angles and moments in children and adolescents with pathological varus alignment of the knee without signs of knee osteoarthritis (OA). Moreover, we wanted to know if compensatory mechanisms are present in this young patient group. Fourteen, otherwise healthy patients with varus malalignment of the knee and 15 healthy control subjects were analysed. Patients showed a reduced knee extension and a significantly lower maximum knee extension moment in terminal stance compared to controls. The maximum knee adduction moment in mid and terminal stance and the maximum hip abduction moment in loading response were significantly higher in the patient group. In the transverse plane, abnormally increased knee internal rotation and hip external rotation moments were present in patients with varus malalignment. These findings imply that varus malalignment is not an isolated problem in the frontal plane. In contrast to adult patients with established medial knee OA, the young patients assessed in the present study did not show typical compensatory mechanisms such as increased foot progression angle or reduced walking speed. This suggests that children and adolescents with varus malalignment of the knee probably do not need to alter their spatio-temporal gait parameters in order to decrease knee joint loading. © 2011 Elsevier B.V.

PubMed | Goethe University Frankfurt and Orthopedic University Hospital Friedrichsheim gGmbH
Type: | Journal: Gait & posture | Year: 2016

Current surgery outcome evaluations in patients with Legg-Calv-Perthes disease (LCPD) are usually based on static radiological changes. The aim of the present study was to assess the development of characteristic gait parameters and passive hip range of motion (ROM) measurements during the postoperative period up to healed stage of the femoral head represented by Stulberg classification. Twelve children (10 male, 2 female) with unilateral diagnosis of LCPD and 19 healthy control subjects at the same age participated in this prospective longitudinal study. Instrumented gait analysis was performed preoperatively, 13.4 (1.7), and 28.0 (4.4) months postoperatively. At final follow-up, the mean leg length of the involved side was reduced by 1.10 (0.53)cm compared to the non-involved side. In addition, a significant reduction in maximum knee flexion (-26%, p=0.037) and knee flexion/extension ROM (-26%, p=0.017) in stance was still present in the patient group compared to controls indicating a stiff knee gait pattern. In contrast, the sagittal plane hip parameters, the ipsilateral trunk lean toward the involved stance limb, and the knee and hip joint loading during gait normalized during the postoperative period. The results of the present study should motivate further exploration if patients with LCPD stiffen their knees to compensate for leg length discrepancy. Besides the standard radiological evaluation of the surgery outcome, instrumented gait analysis is a valuable method of recording functional deficits and early recognition of the need for physiotherapeutic treatment or insole supply in patients with LCPD.

PubMed | Orthopedic University Hospital Friedrichsheim gGmbH
Type: Journal Article | Journal: Journal of aging and physical activity | Year: 2016

The present study should reveal differences in gait performance, quadriceps strength, and physical activity (PA) between fallers and nonfallers in women with osteoporosis. Forty-one women with osteoporosis (17 fallers, 24 nonfallers) participated. Gait analysis shows that fallers were walking with a slower walking speed (-9%, p = .033) and had a shorter stride length (-7%, p = .039). Moreover, fallers showed a decreased ankle power generation (-18%, p = .045). The quadriceps strength was decreased by 24% for fallers (p = .005) while PA showed no significant differences. Although a decrease in ankle power generation could have an effect on floor clearance for limb advancement in the swing phase, the causal relationship between spatiotemporal parameters (walking speed, stride length) and walking ankle joint power generation remains unknown and warrants further investigation. In conclusion, walking speed, stride length, ankle power generation, and quadriceps strength can be used to differentiate between fallers and nonfallers in women with osteoporosis.

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