Refine
Document Type
- conference proceeding (article) (13)
- Article (8)
Has Fulltext
- no (21)
Is part of the Bibliography
- no (21)
Keywords
- Hüftgelenkprothese (4)
- Biomechanics (3)
- Bewegungsapparat (2)
- Biomechanik (2)
- Gait analysis (2)
- Simulation (2)
- THA (2)
- Abduction tasks (1)
- Biomechanische Analyse (1)
- Combined anteversion (1)
- Computer-assisted surgery (1)
- Computerunterstütztes Verfahren (1)
- Conventional surgery (1)
- Early recovery (1)
- Femur first (1)
- Ganganalyse (1)
- Glenohumeral stability (1)
- Kniegelenkband (1)
- Lastverteilung <Statik> (1)
- Leg length (1)
- Mechanische Belastung (1)
- Minimal-invasive Chirurgie (1)
- Muscle weakness (1)
- Musculoskeletal Modeling (1)
- Offset (1)
- Operationstechnik (1)
- Rotator cuff tears (1)
- Rotatorenmanschettenriss (1)
- Schultergelenk (1)
- Stabilität (1)
- Steifigkeit (1)
- THR (1)
- critical hip joint loading (1)
- cup loading (1)
- force angles (1)
- force pathways (1)
- functional outcome (1)
- rim loading (1)
- subject-specific musculoskeletal modeling (1)
- total hip replacement (1)
Institute
- Labor Biomechanik (LBM) (21) (remove)
Begutachtungsstatus
- peer-reviewed (7)
A key requirement in both native knee joints and total knee arthroplasty is a stable capsular ligament complex. However, knee stability is highly individual and ranges from clinically loose to tight. So far, hardly any in vivo data on the intrinsic mechanical of the knee are available. This study investigated if stiffness of the native ligament complex may be determined in vivo using a standard knee balancer. Measurements were obtained with a commercially available knee balancer, which was initially calibrated in vitro. 5 patients underwent reconstruction of the force-displacement curves of the ligament complex. Stiffness of the medial and lateral compartments were calculated to measure the stability of the capsular ligament complex. All force-displacement curves consisted of a non-linear section at the beginning and of a linear section from about 80 N onwards. The medial compartment showed values of 28.4 ± 1.2 N/mm for minimum stiffness and of 39.9 ± 1.1 N/mm for maximum stiffness; the respective values for the lateral compartment were 19.9 ± 0.9 N/mm and 46.6 ± 0.8 N/mm. A commercially available knee balancer may be calibrated for measuring stiffness of knee ligament complex in vivo, which may contribute to a better understanding of the intrinsic mechanical behaviour of knee joints.
We have developed a novel, computer-assisted operation method for minimal-invasive total hip replacement (THR) following the concept of “femur first/combined anteversion,” which incorporates various aspects of performing a functional optimization of the prosthetic stem and cup position (CAS FF). The purpose of this study is to assess whether the hip joint reaction forces and patient’s gait parameters are being improved by CAS FF in relation to conventional THR (CON). We enrolled 60 patients (28 CAS FF/32 CON) and invited them for gait analysis at three time points (preoperatively, postop six months, and postop 12 months). Data retrieved from gait analysis was processed using patient-specific musculoskeletal models. The target parameters were hip reaction force magnitude (hrf), symmetries, and orientation with respect to the cup. Hrf in the CAS FF group were closer to a young healthy normal. Phase-shift symmetry showed an increase in the CAS FF group. Hrf orientation in the CAS FF group was closer to optimum, though no edge or rim-loading occurred in the CON group as well. The CAS FF group showed an improved hrf orientation in an early stage and a trend to an improved long-term outcome.
A prospective randomized controlled trial is presented that is used to compare gait performance between the computer assisted Femur First (CAS FF) operation method and conventional THR (CON). 60 patients underwent a 3D gait analysis of the lower extremity at pre-operative, 6 months post-operative and twelve months post-operative. Detailed verification experiments were facilitated to ensure the quality of data as well as to avoid over-interpreting of the data. The results confirm a similar data-quality as reported in the literature. Walking speed, range of motion and symmetry thereof improved over the follow-up period, without significant differences between the groups. While all parameters do significantly increase over the follow-up period for both groups, there were no significant differences between them at any given time-point. Patients undergoing CAS FF showed a trend to improved hip flexion angle indicating a possible long-term benefit.