Table 2 Summary of studies reporting trunnion design

Tan et al. [15]

44

28-mm heads; six taper designs

Significantly greater corrosion scores within the trunnion base zone (P = 0.018)

Brock et al. [16]

104 female tapers, 11 stem trunnions

Short 12/14 trunnions versus long 11/13 trunnions

Higher rate of material loss with shorter trunnion compared to longer trunnion (0.402 vs 0.123 mm³/year; P = 0.035)

Porter et al. [4]

85

Stems released between 1983 and 2012; 10 different taper designs; five metal alloys from 16 manufacturers

Negative correlation between flexural rigidity (−0.23; P = 0.04) and trunnion length (−0.53; P < 0.001) with release date of the stem. Multiple regression analysis showed flexural rigidity (β = −0.17) and trunnion length (β = −0.51) were independently correlated with time

Nassif et al. [18]

40

Taper diameters: type one (eight hips), 11/13 (six hips), 12/14 (26 hips)

Higher fretting scores in 11/13 compared to type one tapers (P = 0.005)