近排腕骨切除术后对腕关节生物力学影响的实验研究

Experimental study of the biomechanical effect of proximal row carpectomy

目的测定正常腕关节和近排腕骨切除术后腕关节的活动范围和生物力学变化,探讨近排腕骨切除术后腕关节功能丧失和并发症出现的机制。方法选用16例新鲜腕关节标本,通过CSS-44020系列生物力学试验机(中国长春试验机研究所制造),牵引腕关节于被动掌屈、背伸、尺偏和桡偏位,测量正常腕关节和近排腕骨切除术后腕关节的活动范围。然后在腕关节内放置压敏片,于中立位对腕关节施压,分析压敏片上相关信息。结果正常腕关节标本掌屈(74.2°±4.9°,-x±s,下同)、背伸63.3°±3.6°、尺偏36.8°±2.6°、桡偏20.2°±3.4°。近排腕骨切除后掌屈48.1°±5.6°、背伸43.6°±4.6°、尺偏21.0°±4.3°、桡偏10.3°±4.1°。正常腕关节的受力面积平均为(640.57±23.15)mm2,近排腕骨摘除组为(81.26±2.38)mm2。正常腕关节负荷压力为(27.68±0.73)N/cm2,近排腕骨切除组为(169.81±2.27)N/cm2。结论近排腕骨切除术后腕关节活动范围丧失较大,其应力负荷的增加明显超出了正常腕关节所承受的压力负荷,使腕关节功能丧失较多并容易在术后产生腕关节退行性关节炎等并发症。

Objective To investigate the motion and the biome chanical changes of the normal wrist and the wrist after proximal row carpectomy （PRC）, and to provide theoretical basis of the functional loss of wrists following PRC. Methods 16 fresh-frozen human forearm specimens were used. These specimens were placed on the CSS- 44020 biomechanical test machine, and driven to make the movement of flexion, extension, radial deviation and ulnar deviation. Range of motion of the wrists was checked. Pressure sensitive films were inserted into the wrists, and the wrists were pressed at neutral position to collect data of the loaded wrist. Results Range of motion of the normal wrist is as follows： 74.2°± 4.9° flexion, 63.3°± 3.6° extension, 20.2°± 3.4°radial deviation, and 36.8°± 2.6° ulnar deviation. Range of motion in wrists after PRC changed to 48.1°± 5.6°flexion, 43.6°± 4.6° extension, 10.3°± 4.1° radial deviation, and 21.0°±4.3° ulnar deviation. The pressed area of the normal wrist was 640.57± 23.15（mm^2 ）. The pressure intensity of the normal wrist was 27.68± 0.73 （ N/cm^2 ）, while that of PRC wrist 169.81± 2.27 （ N/ cm^2）. Conclusion Proximal row carpectomy significantly reduced range of motion of the wrist, and increased general wrist pressure intensity. The radiocapitate joint formed after PRC is abnormal and is subject to degenerative changes.