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Identifier

000367093

Title

Ανάπτυξη και αξιολόγηση μιας γενικευμένης διαγνωστικής μεθόδου στην ορθοπαιδική βασισμένη στην κινησιομετρία του ανθρώπινου σώματος

Alternative Title

Development and evaluation of a generalized diagnostic method in orthopedics based on kinesiology of human body

Author

Τζαγκαράκης,Γεώργιος Ν

Thesis advisor

Κατώνης, Παύλος

Reviewer

Καμπάνης, Νίκος
Κοντάκης, Γελωργιος
Βελεγράκης, Γεώργιος
Δουγαλής, Βασίλης
Τερσένοβ, Άλκης
Χλουβεράκης, Γρηγόρης

Abstract

Aim: Development and evaluation of a new method based on theory of statistical entropy. The new method is going to permit an objective and quantitative evaluation of the gait characteristics in patients with Lumbar Spinal Stenosis (LSS) and will be useful for the evaluation of responses to surgical treatment in these subjects. It will also permit an objective and quantitative evaluation of the gait variability of patients with excessive Anterior Cruciate Ligament (ACL) Rupture. Methods: Oswestry Disability Questionnaire (ODQ) forms were completed. A tri-axial accelerometer sensor was used for the gait measurement and entropy algorithm was used for accelerometer data analysis. The measurement device measured the approximate gait acceleration of the centre of gravity (COG) of the subject body. All subjects were instructed to walk along a 40 m straight hospital level walkway at a self-selected walking speed. Two groups participated at the first study. The experimental group consisted of subjects diagnosed with spinal stenosis (n=35) and the control group consisted of healthy subjects (n=35). The experimental group’s subjects were diagnosed with spinal stenosis, without any other neuromuscular and musculoskeletal pathology or injury, using Magnetic Resonance Imaging (MRI) and Computerized Axial Tomography (CAT) scans. A t-test was used to compare the entropy values between the two groups. A receiver operating characteristic (ROC) analysis was used to assess the diagnostic value of the method. The objective of the second study was to assess the gait variability of lumbar spinal stenosis (LSS) patients and to evaluate quantitatively its postoperative progression. Twelve (12) subjects with LSS were measured before and after surgery. Preoperative measurements were performed 2 days before surgery. Postoperative measurements were performed 6 and 12 months after surgery. Repeated measures analysis of variance (ANOVA) was used to test whether there was a significant surgery effect on entropy at 6 and 12 months postoperatively. In the case of a statistically significant finding, post hoc Bonferroni adjusted tests were needed to pinpoint differences. The objective of the third study was to compare the gait variability of patients with excessive anterior cruciate ligament (ACL) deficiency (experimental group) with that of healthy individuals (control group) using the proposed method. The experimental group consisted of 20 men with an ACL tear and the control group consisted of 20 healthy men without any neurological and/or musculoskeletal pathology or injury. A receiver operating characteristic (ROC) analysis was used to assess the diagnostic value of the method. Results: For the first study, the ROC analysis estimated a 97.1% probability for correct identification of patients (sensitivity) and an 80.0% probability for correct identification of healthy subjects (specificity). According to ROC analysis, the entropy index has a 97.6% probability for distinguishing between patients with spinal stenosis and healthy subjects. The positive likelihood ratio (PLR) was 4.86 and the negative likelihood ratio (NLR) was 0.21. The Spearman correlation coefficient between entropy values and Oswestry scores for the experimental group was 0.654. In the second study, repeated measures ANOVA revealed that there was a statistical significant surgery effect (p<0.001). The preoperative and postoperative measurements of the LSS patients’ comparison indicated a statistically significant decrease in entropy for each patient. Post hoc Bonferroni adjusted tests yield that there was a statistically significant reduction in gait variability postoperatively. In the third study, the entropy index of the experimental group in the medio– lateral axis, but not the anterior–posterior axis, was statistically significantly higher (P< 0.0001) than that of the control group. For the medio–lateral axis, the ROC analysis estimated a 90% probability for the correct identification of patients (sensitivity) and an 85% probability for the correct identification of healthy subjects (specificity). According to the ROC analysis, the entropy index had a 95.6% probability for distinguishing between ACL patients and healthy subjects. The positive likelihood ratio (PLR) was 6.0 and the negative likelihood ratio (NLR) was 0.17. Thus, the LR values of gait variability suggested that the method has strong diagnostic value for using the medio– lateral axis data. Conclusions: The proposed method permits an objective and quantitative evaluation of the gait characteristics in patients with LSS and is useful for the evaluation of responses to surgical treatment in these subjects. It also permits objective and quantitative evaluation of the gait characteristics in patients with ACL Rupture. The proposed method is also painless, low-cost, non-invasive, requires no radiation or chemicals and the objective index that corresponds to gait irregularity may be computed instantly.

Language

Greek

Subject

Accelerometry

Anterior cruciate ligament rupture

Biosignal analysis

Entropy

Gait variability

Musculoskeletal system

Postoperative estimation

Spine diseases

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