|Title:||Vibration Arthrometry in the Patients with Failed Total Knee Replacement||Authors:||JIANG, CHING-CHUAN
|Keywords:||cartilage degeneration;crepitus;failed total knee replacement;knee joint;parametric modeling;vibration arthrometry (VAM)||Issue Date:||2000||Journal Volume:||v.47||Journal Issue:||n.2||Start page/Pages:||219-227||Source:||IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING||Abstract:||
This is a preliminary research on the vibration arthrometry of artificial knee joint in vivo. Analyzing of the vibration signals measured from the accelerometer on patella, there are two speed protocols in knee kinematics : 1 ) 2°/s, the signal is called “physiological patellofemoral crepitus ( PPC)”, and 2) 67°/s, the signal is called“ vibration signal in rapid knee motion”. The study had collect 14 patients who had revision total knee arthroplasty due to prosthetic wear or malalignment represent the failed total knee replacement (FTKR), and 12 patients who had just udergone the primary total knee arthroplasty in the past two to six months and have currently no knee pain represent the normal total knee replacement (NTKR). FTKR is clinically divided into three categories: metal wear, polyethylene wear of the patellar compartment, and no wear but with prosthesis malalignment. In PPC, the value of root mean square (rms) is used as a parameter; in vibration signals in rapid knee motion, autoregressive modeling is used for adaptive segmentation and extracting the dominant pole of each signal segment to calculate the spectral power ratios in f < 100 Hz and f > 500Hz. It was found that in the case of metal wear, the rms value of PPC signal is far greater than a knee joint with polyethylene wear and without wear, i .e., PPC signal appears only in metal wear. As for vibration signals in rapid knee motion, prominent time- domain vibration signals could be found in the FTKR patients with either polyethylene or metal wear of the patellar component. We also found that for normal knee joint, the spectral power ratio of dominant poles has nearly 80% distribution in f > 500 Hz, spectral power ratio of dominant poles has over 30% distribution in metal wear but only non- significant distribution in polyethylene wear, no wear, and normal knee. The results show that vibration signals in rapid knee motion can be used for effectively detecting polyethylene wear of the patellar component in the early stage, while PPC signals can only be used to detect prosthetic metal wear in the late stage.
|Appears in Collections:||醫學系|
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