Review Question - QID 3616

Posterior blocking screws in the proximal tibial segement help to avoid tibial procurvatum deformity and malunion. Proximal third tibia fractures are often times difficult to reduce anatomically due to the tendency for both valgus and flexion deformity at the fracture site. The posterior blocking screw helps to eliminate the tendency for the nail to be too posterior and cause the fracture to flex. Blocking screws should be placed on the concavity of the deformity to minimize the procurvatum and valgus deformities of this fracture pattern.

Krettek et al looked at the importance of using blocking screws during intramedullary nailing of metaphyseal fractures using small diameter nails. They found less procurvatum deformity and malunions associated with using of blocking screws and found no complication with their utilization.

Ricci et al reviewed fractures of the proximal third of the tibial shaft treated with intramedullary nails and blocking screws. Their results supported that blocking screws were effective in maintaining alignment of fractures of the proximal third of the tibial shaft treated by intramedullary nailing.

Hiesterman et al review different reduction techniques to avoid malalignment, including the use of a proper starting point and insertion angle, blocking screws, unicortical plates, and a universal distractor.

Illustration A shows a radiograph utilizing posterior proximal and distal blocking screws to prevent procurvatum deformity.

Incorrect Answers:
1- would exacerbate procurvatum deformity.
2- would help avoid valgus deformity.
3- would exacerbate valgus deformity.
4- would exacerbate procurvatum deformity.