| UNIVERS~TM 3-D PROTHESIS, a new generation shoulder prosthesis, was developed to restore the nature state of shoulder anatomy from the third generation shoulder prosthesis. Up to now, it has been used for about 7 years since 1997. The purpose of the present study was to evaluate adaptability of UNIVERS~TM 3-D Prothesis to shoulder and it's clinical outcome independently. This study was divided into two parts: 1.Adaptability of UNIVERS~TM 3-D Prothesis to shoulder; 2. The clinical outcome of UNIVERS~TM 3-D Prothesis.Part 1. Adaptability of UNIVERS~TM 3-D Prothesis to shoulderTo evaluate adaptability of UNIVERS~TM 3-D prosthesis to shoulder, this study included comparison between the UNIVERS~TM 3-D implant and shoulder anatomy data, mechanics test of UNIVERS~TM 3-D prosthesis, and advantage of metal backed glenoid component with cage screw compared with the UNIVERS~TM 3-D cemented glenoid implant. we found:1. UNIVERS~TM 3D humeral head component is freely adjustable in inclination, ante-/ retrotorsion and eccentricity, which are the most important factors in the shoulder prosthesis design. The prosthesis inclination angle is changed from 125 to 140 degrees, covered the normal shoulder angle, 129.6±2.9(123.2-135.8) degrees. The ante-/ retrotorsion angle, from –15 to 15 degrees, nearly satisfied normal range, 17.9±13.7 (from -6.7 to -47.4)degrees. The eccentricity offset is 3.5mm, changed in 5 directions. The stem designs, including the stem size, length, titanium alloy, rough-blasted surface, metaphyseal blocking, conical shaped distal stem, are adaptable to shoulder anatomy. On the other hand, the designs of glenoid component including metal back with cage screw, maximal height, radius mismatch, sizes, are also matching to glenoid anatomy.2. Mechanics test of UNIVERS~TM 3-D prosthesis. By the test of EMPA machine special for mechanics test we found, the junction bolt between humeral stem and head had no any change under the cyclic load test with 1,300 N, and more than 1,000,000 alterations. The maximal tensile loading of cage srew fixation is 3,900 N, and the maximal draw-out strength is 1,400N. No failure of the cementless glenoid occured after 500.000 load (1.3 kN) alternations in anterior-posterior direction and 1.000.000 alterations in cranio-caudal direction. These prove that the fixation of UNIVERS~TM 3-D Prothesis is very stable, and also adaptable to shoulder biomechanics.3. Compared with UNIVERS~TM 3-D cemented glenoid implant, uncemented glenoid implant with cage screw got same osteointegration, equal distribution of loads, solid bony fixation, minimal reaming of glenoid, conserving bone stock.. The bone loss in the cemented glenoid implant was 7 times as in the uncemented glenoid implant.Part 2. The clinical outcome of UNIVERS~TM 3-D ProthesisUNIVERS~TM 3-D Prothesis was used to treat a series of shoulder diseases, including primary osteoarthritis (OA), post-traumatic osteoarthritis (PA), instibility arthritis (IA), rheumatoid arthritis (RA), nontraumatic osteonecrosis (NTON), rotator cuff tear arthropathy (RCTA), and so on. Our clinical follow-up included clinical function results (Constant score and normalized Constant score), radiological analysis on preoperative and postoperative X-ray (three AP views: neutral, external and internal rotation; scapular view and axillary view) in all kinds of shoulder diseases.1. Clinicial and radiological results of OA(1) Most of cases had the typical pathology: periarticular osteophytes of humeral head, humeral head necrosis, cyst, flattening or bone loss, periarticular osteophytes of glenoid, shortening of acromion-humerus head distance (AHD), narrowing of glenohumeral joint distance (GHD), and so on.(2) There were the pre-op Constant scores in 82 cases, post-op clinical Constant score with 12-74 months (mean 31.9 months) in 74 cases. The postoperative Constant score and normalized Constant score (92.27±22.53%) were very close to normal, increased more than one time. The pain, activity, mobility, strength score were all increased obvio... |
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