Artikel
Residual rotation of forearm amputation: Cadaveric study
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Veröffentlicht: | 6. Februar 2020 |
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Gliederung
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Objectives/Interrogation: The purpose of this study was to investigate the residual rotation of the patient with forearm amputation and the contribution of involved muscle to the residual rotation. Finally, we tried to determine the optimal amputation level for the forearm bionic arm.
Methods: Testing was performed using 5 fresh-frozen cadaveric specimens that were surgically prepared by isolating muscles involved in forearm rotation. Amputation was implemented at 25 cm (wrist disarticulation), 18 cm and 10 cm from tip of olecranon. The supination and pronation in the amputation stump was simulated with traction of involved muscle (supinator, biceps brachii, pronator teres, pronator quadratus) using an electric actuator. The degree of rotation was examined at 30°, 60°, 90° and 120° in flexion of elbow.
Results and Conclusions: Average rotation of 25 cm forearm stump was 148° (SD 23.1). The rotation was decreased to 117.5° (SD 26.6) at 18 cm forearm stump and to 63° (SD 31.5) at 10 cm forearm stump. Tendency of disorganized rotation was observed in close proximity of the amputation site to the elbow. Full residual pronation was achieved with traction of each pronator teres and pronator quadratus. Although traction of supinator could implement residual supination, the contribution of biceps brachii range from 4% to 88% according to the degree of flexion.
Close proximity of the amputation site to the elbow decreased the residual rotation significantly and the preservation of pronosupination was 80% at 18 cm forearm stump. Although the pronator teres and the pronator quadratus could make a full residual pronation separately, the supinator was essential to a residual supination.