The use of 'blocking' screws for the 'closed' reduction of difficult proximal and distal femoral fractures

Abstract

Most meta-diaphyseal femoral fractures that are treated with intramedullary nailing can be reduced satisfactorily by skeletal traction without 'opening' the fracture site and therefore, complications such as nonunion, infection and wound healing problems are reduced.In cases where adequate fracture reduction cannot be achieved by skeletal traction, 'reduction aids' have been used during the operative procedure in order to avoid the exposure of the fracture site.The 'blocking' screw, as a reduction tool, was proposed initially for the 'difficult' metaphyseal fractures of the tibia. Subsequently, surgeons have tried to implement the 'blocking' screw technique in 'difficult' distal femoral fractures.This article presents the 'blocking' screw technique as an adjunctive process in the management of fractures of the proximal and distal femur which are found to be non-reducible by skeletal traction alone. The minimal invasiveness of the technique contributes greatly to the preservation of both the soft tissue integrity and the fracture haematoma and thus reduces the major complications that can occur by exposing the fracture site. Cite this article: EFORT Open Rev 2021;6:451-458. DOI: 10.1302/2058-5241.6.210024.

Keywords: blocking screw; difficult femoral fracture reduction; intramedullary nailing.

Fig. 1

(a) Segmental ‘closed’ fracture of the right femur in a 33-year-old male. (b) (c) Intraoperative fluoroscopic images showing the displacement in both antero-posterior (AP) and lateral views and the insertion of an AP ‘blocking’ screw, perpendicular to the displacement on the coronal plane, in the proximal fragment, at the lateral side of the guide wire, as the bony segment where the ‘blocking’ screw has been inserted must move laterally. (d) (e) A second ‘blocking’ screw has been inserted at the distal segment, in a medio-lateral direction in order to contribute towards the reduction of the distal fracture on the sagittal plane. (f) (g) Final intraoperative views depicting the good overall ‘closed’ reduction at the distal fracture site. The proximal fracture site was reduced by the introduction of the nail. (h) AP postoperative X-ray.

Fig. 2

(a) Segmental ‘closed’ fracture of the right femur in a 48-year-old female. (b) (c) (d) Intraoperative fluoroscopic images showing good reduction proximally and gross displacement in both antero-posterior (AP) and lateral views at the distal fracture site. (e) The guide wire diverts the nail towards the medial condyle. The nail followed the same direction even when the guide wire was withdrawn. (f) (g) The nail was withdrawn and a second curved guide wire was introduced just to indicate the best location for the insertion of the ‘blocking’ screw. (h) The ‘blocking’ screw diverted the nail at the correct direction and allowed flexibility in the final positioning of the nail, so an optimal position of the lag screw proximally could be obtained. (i) AP X-ray at four months showing healing of both fracture sites with sizable callus formation.

Fig. 3

(a) Antero-posterior (AP) view of a segmental ‘closed’ fracture of the right femur in a 52-year-old male. (b) (c) (d) Intraoperative fluoroscopic images showing the initial position of the proximal (AP) and distal (AP and lateral) fracture sites under skeletal traction. (e) AP view of the distal femur that shows the tendency for the nail to follow an eccentric trajectory. (f) As the guide wire crosses the pathway of the ‘blocking’ screw, it is withdrawn (but not removed from the distal segment) and the ‘blocking’ screw is inserted antero-posteriorly, at a position (g) (h) that will allow both the insertion of the nail and its direction towards the middle of the distal femur. (j) AP X-ray at three months when the patient was instructed to fully weight-bear.

Fig. 4

(a) (b) Preoperative AP and lateral X-rays of a 78-year-old female that show an extensive, oblique sub-trochanteric fracture of the right femur with marked anterior displacement on the lateral view. (c) (d) Intraoperative fluoroscopic images showing the initial position of the fracture under skeletal traction. (e) (f) Positioning of the drill-bit on the lateral view and insertion of the ‘blocking’ screw at the trochanteric area. (g) (h) Following the reduction of the fracture with the reduction tool (‘joy-stick’), the insertion of the guide wire and reaming, the insertion of the nail above the ‘blocking’ screw, reduces the fracture. (i) (j) Postoperative antero-posterior (AP) and lateral X-rays show excellent reduction of the fracture.

Fig. 5

(a) Preoperative antero-posterior (AP) X-ray of a 65-year-old male that shows a comminuted sub-trochanteric fracture of the left femur with mainly lateral displacement. (b) (c) Intraoperative fluoroscopic images showing the initial position of the fracture site under skeletal traction and the point of insertion of an AP ‘blocking’ screw. (d) (e) Insertion of nail lateral to the ‘blocking’ screw reduced the fracture. (f) (g) AP and lateral X-rays at four months show solid callus formation and the patient was instructed to fully weight-bear.