Biomechanical comparison for the stability of the greater tuberosity between different fixation methods during humeral head replacement
- VernacularTitle:人工肱骨头置换术中大结节不同固定方式的稳定性研究
- Author:
Chunyan JIANG
;
Yiming ZHU
;
Yi LU
- Publication Type:Journal Article
- Keywords:
Shoulder Joint;
Arthroplasty, replacement;
Biomechanics
- From:
Chinese Journal of Orthopaedics
1999;0(07):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate and compare the biomechanical stability between anatomical and overlapping reconstruction of the greater tuberosity in cadaveric humeral head replacement model. Methods Eight pair (16) fresh-frozen shoulder cadavers were match-paired into 2 groups. Four-part fracture model was created in all cadavers. Standardized humeral head replacement procedure was carried out in all specimens, and anatomical and overlapping reconstruction of the greater tuberosity was applied to each group respectively. Custom mounting apparatus and fixation jigs were designed for designated shoulder motion. A Binocular 3D Computer Vision metrical method was employed to measure the displacement of greater tuberosity relative to the humeral diaphysis. Results When the shoulder was external rotated to neutral position, the mean displacement of greater tuberosity in anatomical reconstruction group was (1.81?1.75) mm,while the mean displacement was (3.23?2.91) mm in overlapping group. Statistical difference was found between the 2 groups. When the glenohumeral joint was elevated to 30? and 60? forward flexion, the mean displacement of greater tuberosity in anatomical group was (4.01?5.00) mm and (5.99?6.97) mm respectively, while the mean displacement was (3.02?5.27) mm and (6.97?7.00) mm respectively in overlapping group. No statistical difference was found between the 2 groups during forward flexion measurement. Conclusion In cadaveric humeral head replacement model, anatomic greater tuberosity reconstruction shows better mechanical stability compared with overlapping reconstruction during external rotation to neutral position. This result suggests that there may be some loss in mechanical stability in overlapping fixed greater tuberosity. Even though standardized postoperative rehabilitation protocol are strictly followed, evident displacement of the greater tuberosity was detected. Postpone of the postoperative rehabilitation program after humeral head replacement for a decent period of time may benefit tuberosity healing.
