Ross Mark, Di Mascio Livio, Peters Susan, Cockfield Allen, Taylor Fraser, Couzens Greg
Brisbane Hand and Upper Limb Research Institute, Brisbane, Australia ; Orthopaedic Department, Princess Alexandra Hospital, Brisbane, Australia ; School of Medicine, The University of Queensland, Brisbane, Australia.
Brisbane Hand and Upper Limb Research Institute, Brisbane, Australia ; Orthopaedic Department, St Bartholomew's and the Royal London Hospital, London, United Kingdom.
J Wrist Surg. 2014 Feb;3(1):22-9. doi: 10.1055/s-0033-1357758.
Instability of the distal radioulnar joint (DRUJ) is a complication that can occur following distal radius fracture or malunion. We have observed that residual radial translation of the distal radius, relative to the radial shaft, may be a causal factor of DRUJ instability, even once the traditional radiographic parameters (volar tilt, radial inclination, and ulnar variance) have been restored. Residual radial translation of the distal fragment may cause detensioning of the distal interosseous membrane (IOM) and pronator quadratus with poor apposition between the ulnar head and sigmoid notch. This may potentially lead to persistent instability of the ulnar head following internal fixation. Residual radial translation deformity is at risk of being overlooked by the wrist surgeon as there is no existing radiographic parameter that accurately measures this deformity.
In this study, 100 normal wrist radiographs were reviewed by three fellowship-trained orthopedic surgeons to develop a simple and reproducible technique to measure radial translation.
Utilizing the method described, the point of intersection between the ulnar cortex of the shaft of the radius and the lunate left a mean average of 45.48% (range 25–73.68%) of the lunate remaining on the radial side. In the majority of cases more of the lunate resided ulnar to this line. High levels of agreement with inter-rater (intraclass coefficients = 0.967) and intra-rater (intraclass coefficients = 0.79) reliability was observed.
The results of this study can be used to define a normal standard against which residual radial translation can be measured to assess the reduction of distal radius fractures. This new parameter aids in the development of surgical techniques to correct residual radial translation deformity. In addition, awareness and correction of this potential malreduction at the time of surgery may decrease the need for other procedures on the ulnar side of the wrist to improve DRUJ stability, such as ulnar styloid fixation, TFCC repair, or ligamentous grafting [corrected].
桡尺远侧关节（DRUJ）不稳定是桡骨远端骨折或畸形愈合后可能出现的并发症。我们观察到，即使传统的影像学参数（掌倾角、桡骨倾斜角和尺骨变异）已恢复正常，桡骨远端相对于桡骨干的残余桡侧移位仍可能是DRUJ不稳定的一个致病因素。远端骨折块的残余桡侧移位可能导致远侧骨间膜（IOM）和旋前方肌张力减小，尺骨头与乙状切迹之间对合不良。这可能潜在地导致内固定后尺骨头持续不稳定。由于目前没有准确测量这种畸形的影像学参数，残余桡侧移位畸形有被腕关节外科医生忽视的风险。
在本研究中，三位接受过专科培训的骨科医生对100张正常腕关节X线片进行了评估，以开发一种简单且可重复的测量桡侧移位的技术。
采用所述方法，桡骨干尺侧皮质与月骨的交点平均使月骨的45.48%（范围25%-73.68%）留在桡侧。在大多数情况下，月骨的更多部分位于这条线的尺侧。观察到评分者间（组内系数=0.967）和评分者内（组内系数=0.79）的可靠性具有高度一致性。
本研究结果可用于定义一个正常标准，据此可测量残余桡侧移位以评估桡骨远端骨折的复位情况。这个新参数有助于开发纠正残余桡侧移位畸形的手术技术。此外，在手术时意识到并纠正这种潜在的复位不良可能会减少在腕关节尺侧进行其他改善DRUJ稳定性的手术的必要性，如尺骨茎突固定、TFCC修复或韧带移植[已修正]。
