Measurement of the Shoulder Motion Using 3-D Motion Capture Technique / 대한정형외과연구학회지

PURPOSE: Measurement of scapular motion as a component of shoulder motion is clinically limited. The purpose of this study was to measure the scapulothoracic motion and glenohumeral motion separately using the 3-D motion capture technique. MATERIALS AND METHODS: Twelve healthy adult male volunteers (Mean age: 28 years) without any history of shoulder pathologies were included for the study. Shoulder motions in 3 planes -forward flexion, abduction in scapular plane and abduction in coronal plane- were measured in 3-dimensions. And we estimated skin slippage of optical markers according to the flexion of the shoulder using ultrasonography. RESULTS: During forward flexion, abduction in scapular plane and abduction on coronal plane, scapula showed upward rotation, external rotation and posterior tilting. Especially, during abduction on coronal or scapula plane, scapula was upwardly rotated and posteriorly tilted in linear fashion. The scapulo-humeral rhythm was 6.7:1 in whole range of abduction on the coronal and scapular plane. Estimated skin slippage of the marker on the inferior angle of scapula was 4.3+/-1.7 cm and bigger than those of other markers. CONCLUSION: This study failed to get a useful data of shoulder motion due to marker position which did not reflect scapula motion actually. But this trial could be a help for the future study, as this study suggested the possibilities of 3-D motion capture technique for the measurement of shoulder motion.

Medial Unicompartmental Knee Arthroplasty in Patients with Spontaneous Osteonecrosis of the Knee

BACKGROUND: We analyzed the clinical and radiologic results of patients with spontaneous osteonecrosis of the knee treated by minimally invasive medial unicompartmental arthroplasty using Oxford Uni. METHODS: We reviewed 22 knees in 21 patients which were treated for spontaneous osteonecrosis between 2002 and 2006. Patients included one male and 20 females. The mean age was 70.8 years (range, 53 to 82 years). The mean follow-up period was 70.3 months (range, 48 to 93 months). The clinical results were evaluated using the Hospital for Special Surgery (HSS) knee score and the range of motion of the knee preoperatively and at the final follow-up. Preoperative plain radiographs and magnetic resonance images were analyzed to determine the size and stage of osteonecrotic lesions. RESULTS: The mean HSS knee score was 64.3 (range, 54 to 75) preoperatively and 92.0 (range, 71 to 100) at the final follow-up. The mean preoperative flexion contracture was 8.9degrees (range, 0 to 15degrees) and 0.2degrees (range, 0 to 5degrees) at the final follow-up. The mean further flexion increased from 138.6degrees (range, 100 to 145degrees) preoperatively to 145.6degrees (range, 140 to 150degrees) at the final follow-up. Active full flexion was possible within 2 months of the operation. The squatting position was possible in 16 patients (84.2%) out of 19, except one case of bronchiectasis and one case of spine fracture. The cross-leg posture was possible in 19 patients (90.5%) out of 21. The mean tibiofemoral angle was improved from varus 0.98degrees to valgus 3.22degrees. Meniscal bearing dislocation occurred in 2 cases and femoral component loosening occurred in 1 case. CONCLUSIONS: Unicompartmental knee arthroplasty using Oxford Uni could be an alternative treatment option in spontaneous osteonecrosis of the knee.