A new technique for lag screw placement in the dynamic hip screw fixation of intertrochanteric fractures: decreasing radiation time dramatically

Abstract

The goal of this study was to confirm the decrease in radiation time required for a new technique to place dynamic hip screws (DHS) in intertrochanteric fractures. Seventy-six patients were treated with DHS by either the new technique (NT) or the conventional technique (CT). The width of femoral shaft, the length of the hip screw to be implanted into the injured side, and the distance between the tip of the greater trochanter and the entry point of the guide wire were measured at the uninjured side on the anteroposterior pelvic radiograph preoperatively, and the actual width of the injured femoral shaft was measured intra-operatively. Finally, the entry point and the length of hip screw were obtained through an equation. Mean radiation time of the NT patients (24.57±7.80 s) was significantly shorter than the CT patients (54.2±18.26 s) (P <0.001). The new technique decreased radiation time dramatically in DHS fixation.Résumé Le but de cette étude est d'évaluer la diminution du temps d'exposition aux rayons X par une nouvelle technique de vissage dynamique de la hanche DHS (NT) comparée à la technique conventionnelle. Matériel et méthode: 76 patients ont été traités par DHS avec cette nouvelle technique (NT) ou la technique conventionnelle (CT). La largeur et la longueur de la vis fémorale implantée et la distance entre le sommet du grand trochanter et le point d'entrée du guide ont été mesurés du côté fracturé par une radiographie de face pré-opératoire et per-opératoire. Finalement, le point d'entrée et la longueur de la vis fémorale sont obtenus par équation. Résultats : l'exposition moyenne aux rayons X de la nouvelle technique (24.57± 7.80s) a été significativement moins importante que dans la technique conventionnelle (54.2±18.26 s) (P<0.001). En conclusion, cette nouvelle technique permet de diminuer le temps d'irradiation de façon importante, lors d'une fixation de fracture fémorale par DHS.

Accuracy of the Lesser Trochanter for Guiding Lag Screw Insertion in Hip Fracture Management

“…Several methods have been described for accurate guidewire placement in fixation. [14][15][16][17][18][19][20][21][22] Some authors locate the entry point approximately 2 cm below the vastus lateralis ridge; however, this method is not reproducible without a reliable osseous landmark. Adams and Stossel 14 used staples as groin skin markers to guide the placement of the guidewire, and Aronson and Carlson 15 used a marker pen instead of staples in the treatment of slipped capital femoral epiphysis.…”

“…However, they did not clearly define a reference landmark on the AP plane, and the study showed no decreased radiation exposure. Sheng et al 22 proposed a geometric equation to calculate the entry point of a Kirschner wire, but the procedure required exposing the lesser trochanter to increased trauma and surgery time.…”

“…6,7,[11][12][13] The crucial part of the operation is insertion of a hip screw into the femoral neck in an exact position over the guidewire. Many techniques have been described for accurate placement of the guidewire in fixation [14][15][16][17][18][19][20][21][22] ; however, no technique has been universally accepted because of the lack of accuracy and reproducibility. Without a clear landmark for insertion, most surgeons rely on intraoperative judgment and images from an image intensifier to perform the procedure.…”

Radiographic quantification of dynamic hip screw migration

“…In 2.5-16 % of cases, the hip screw may ultimately "cut out", i.e. penetrate the femoral head in its superior part [9][10][11][12][13][14][15]. Early detection of DHS® migration is important to reduce patient morbidity.…”