Radiographic analysis of anatomic risk factors for scaphoid fractures; A case-control study

Abstract Aim The purpose of this study was to investigate the role of anatomic variations in distal radius radiographic indices in patients with or without scaphoid fractures. Materials and methods Radial inclination (RI), volar tilt (VT), radial height (RH) and ulnar variance (UV) were measured on wrist radiographs of 320 patients with (Group I, n = 167) or without (Group II, n = 153) scaphoid fracture, fall on outstretched hand (FOOSH). Receiver operating characteristics (ROC) curve analysis was used to assess the diagnostic performance for each variable. Sensitivity (Sn), specificity (Sp), cutoff value, and area under the ROC curve were analyzed. Odds ratio was calculated for defined cutoff values. Results The mean age of the groups was similar (29.3 ± 10.2 vs 31.1 ± 9.9 years, p = 0.060). RI (30.0 ± 2.9 vs 26.8 ± 2.3°) VT (11.4 ± 2.4 vs 10.5 ± 2.2°), RH (14.8 ± 2.1 vs 13.2 ± 1.9 mm), UV (−0.46 ± 1.7 vs 0.00 ± 1.5 mm) were higher in scaphoid fracture group (Gr I vs Gr II, p = 0.000, p = 0.000, p = 0.001, p = 0.012 respectively). Ulna minus variant was more prevalent in fracture group (p = 0.001). Optimal cutoff points for RI, VT, RH and UV in differentiating fractured and intact scaphoid were 28.6° (Sn = 81.0%, Sp = 26.3%), 12.2° (Sn = 80.4%, Sp = 67.1%), 14.85 mm (Sn = 80.4%, Sp = 52.1%) and 0 mm (Sn = 88.6%, Sp = 75.8%), respectively. Odds ratios for defined cutoff points for RI, VT, RH and UV were 10.4 (95% CI, 6.2–17.4), 1.8 (95% CI, 1.1–3.0), 3.7 (95% CI, 2.3–6.2) and 2.2 (95% CI, 1.3–3.7) respectively. Conclusion Increased RI, VT, RH and negative UV were found to be predisposing anatomical risk factors for scaphoid fracture when FOOSH.