Vol. 5, Issue 1, Part A (2023)

Background: Scapholunate dissociation is a common condition in wrist injuries, necessitating precise radiological assessment. The scapholunate distance (SLD) on posteroanterior (PA) wrist radiographs is a critical parameter in diagnosing this condition. However, variations in measurement methods and definitions of "normal" values have led to a need for standardization. 
Methods: We conducted a study to establish a standardized protocol for wrist radiographs and determine normal SLD values in a non-traumatic population. A total of 100 wrist radiographs, primarily taken for non-traumatic indications, were included in the study. Patient positioning, technical factors, and measurement methods were standardized. Demographic data, including age, sex, hand dominance, and diagnosis, were recorded. 
Results: The mean SLD for all 100 wrists was 3.435 mm, with a standard deviation of 1.398 mm. Male wrists had a mean SLD of 3.767 mm (SD 0.27 mm), while female wrists had a mean SLD of 3.178 mm (SD 1.813 mm). A statistically significant difference in SLD was observed between male and female subjects. However, no significant differences were found based on age, handedness, or diagnosis. None of the radiographs exhibited the scaphoid "cortical ring" sign. 
Discussion: The study highlights the variability in SLD measurement methods and the lack of consensus on normal values. Our proposed normal limits, based on gender, are SLDs of up to 5 mm in males and 4.5 mm in females. This research emphasizes the importance of standardized protocols for wrist radiographs and provides valuable reference values for clinical practice. 
Conclusion: Standardizing wrist radiographs and establishing gender-based normal SLD values are essential steps towards accurate diagnosis and management of scapholunate dissociation. Our findings contribute to the improvement of clinical assessment protocols for wrist injuries, ensuring more reliable and consistent results in patient care.