STUDY DESIGN: Experimental.

SAMPLE POPULATION: Fourteen equine cadaver limbs/horses.

METHODS: Simulated fractures were repaired with 2 lag screws under 4-Nm insertion torque (linear repair). Computed tomography (CT) imaging was performed with the leg unloaded and loaded to forces generated while walking. The fracture repair was revised to include 3 lag screws placed with the same insertion torque (triangular repair) prior to CT. The width of the fracture gap was assessed qualitatively by 2 observers and graded on the basis of gap measurements relative to the average voxel size at dorsal, mid, and palmar P1 sites. Interobserver agreement was assessed with Cohen's κ. The effect of repair type, loading condition, and measurement site on fracture gap grades was evaluated by using Kendall's τ-b correlation coefficients and paired nonparametric tests. Significance was set at P ≤ .05.

METHODS: Thirty patients who underwent distal volar locking plate for distal radius fracture were included in a retrospective study. In all 30 patients no dorsal and intra-articular screw penetration were detected on standard AP and lateral views of a plain radiograph. CT scan of the operated wrist was performed to determine the number of intra-articular and dorsal screw penetrations. Clinical examination was performed to determine the wrist functions in comparison to the normal wrist.

RESULTS: Nineteen wrists were noted to have screw penetration either dorsally or intraarticularly. The highest incidence is in the 2nd extensor compartment where 13 screws had penetrated with a mean of 2.46 mm. Six screws penetrated into the distal radial ulnar joint and five screws into the wrist joint with a mean of 2.83 mm and 2.6 mm, respectively. However, there was no incidence of tendon irritation or rupture.