Voorhees D R, Daffner R H, Nunley J A, Gilula L A
Skeletal Radiol. 1985;13(4):257-62. doi: 10.1007/BF00355345.
Negative ulnar variance is a condition in which the ulna is relatively shorter than the radius at the carpus. It was found in 21% of 203 normal wrists. We have observed an increased incidence (49%) of this anomaly in patients with carpal ligamentous instabilities (dorsiflexion instability, palmar flexion instability, scapholunate dissociation with rotary luxation of the scaphoid, and lunate and perilunate dislocations). While the reasons for this association have yet to be adequately delineated, the presence of a negative ulnar variant may serve as an impartial clue to the presence of ligamentous instability. Many carpal instabilities present with subtle radiographic findings requiring careful evaluation of radiographs. Patients with negative ulnar variance and histories suggestive of ligamentous instability should undergo careful radiologic evaluation to assure early diagnosis of carpal disruption.
尺骨负变异是一种尺骨在腕关节处相对比桡骨短的情况。在203例正常腕关节中，有21%发现存在这种情况。我们观察到，在腕关节韧带不稳定（背屈不稳定、掌屈不稳定、舟月骨分离伴舟骨旋转性脱位以及月骨和月周脱位）的患者中，这种异常的发生率增加（49%）。虽然这种关联的原因尚未得到充分阐明，但尺骨负变异的存在可能是韧带不稳定存在的一个客观线索。许多腕关节不稳定表现为细微的影像学表现，需要仔细评估X线片。有尺骨负变异且有韧带不稳定病史的患者应接受仔细的影像学评估，以确保腕关节损伤的早期诊断。
