Single vs double headless compression screw fixation for scaphoid nonunion

Table 2 Post-operative radiographic changes and deformity correction

Variable	1-screw group (n = 15)	2-screw group (n = 8)	Test statistic	P value
∆H/L, median (range)	0.01 (-0.07 to 0.13)	0.02 (-0.09 to 0.34)	U = 49.00	0.476
∆SL (degrees), mean ± SD	-7.27 ± 20.31	-11.75 ± 23.66	t = 0.477	0.639
DISI successfully corrected, n (%)	5 (71.4)	2 (28.6)	N/A	0.286

Change in height-to-length ratio was analyzed using the Mann-Whitney U test. Change in scapholunate angle was analyzed using an independent samples t-test. Dorsal intercalated segment instability correction rates were analyzed using Fisher’s exact test. N/A indicates Fisher’s exact test was used, which computes exact probability directly without generating a standardized test statistic. ∆H/L: Change in height-to-length ratio; ∆SL: Change in scapholunate angle; DISI: Dorsal intercalated segment instability; N/A: Not applicable.