Putting a screw-plate in place using a mini external approach

	Putting a screw-plate in place using a mini external approach Doctor Frédéric Laude
	The classical manner of placing of an external screw plate is commonly practised by raising the vastus lateralis muscle until the proximal femur is greatly exposed. It seems possible to osteosynthesis an intertrochanteric fracture with a sliding screw-plate in a manner much less invasively, without approaching the focus and without having to detach the vastus lateralis, by using a mini external approach.

	PRINCIPLE The point of entry for an external plaque on a femoral diaphysis is situated about 2 to 3 centimetres below the crest on which the vastus lateralis is inserted. This distance is sufficient enough to allow for the placement of a pin guide axial wick with having to detach the vastus lateralis from its trochanteric crest. Thus the continuity between the vastus lateralis and the gluteus medius is conserved. It is sufficient to just lift off the vastus lateralis of the femoral diaphysis and lay it towards the front. As the first two centimetre of the vastus lateralis is not touched, the usual incision cut that is made in order to see this part of the vastus is not necessary.

	Description of the technique The reduction is done on a orthopaedic table with the patient in dorsal decubitus. It is controlled by a brilliancy amplifier or fluoroscope. In most all of the cases involved the fracture is reduced in a satisfactory manner by playing upon the rotation, adduction and traction. The incision cut is modified. It starts, at its upper part, at the level of the intersection between the neck axis and the skin (figure 1). The most simple method for locating the approach is, during the manoeuvres of the reduction examination, pose a long non- sterile pin on the skin that will coincide with the neck axis. These references are inscribed on the skin with an indelible marker. The incision cut is prolonged vertically downwards for 4 to 5 cm. At the end of the intervention, the incision will have been designed over the top the plaque’s diaphysis screw holes. (fig. 6)		Figure 1 : preoperative identification of the incision

	For certain gestures done during the intervention, the approach might seem limited but the skin’s plasticity of elderly patients permits, due to the placing of the Farabeuf retractors in the scar axis, to be more useful than expected. The fascia lata is cut vertically and this cut is extended upwards and downwards beyond the incision cut. A Beckmann retractor is put into place and will lean against the fascia lata at the bottom and upon the vastus lateralis at the top. The incision of the superficial aponeurosis of the vastus lateralis is made in the classic manner by a longitudinal cut at its posterior part. The vastus lateralis is not detached from its trochanteric crest. This access does not pass through the vastus lateralis. The vastus is lifted up with a Lambotte rugine. The self-retaining Beckmann retractor is placed forwards under the vastus lateralis and backwards on the tensor of the fascia lata. The diaphysis is thus exposed from 6 to 7 centimeters. The guide pin of the ancillary is positioned on the diaphysis in the usual manner (figure 2).		Figure 2 : placing the guide pin

	The guide pin should be able to slip under the vastus and come to a joint stop at its upper part between the vastus lateralis and the diaphysis. Not all of the ancillaries are adapted for this technique as some are too bulky and do not easily slide under the vastus. It is preferable that the handle of the guide pin be positioned as low possible on the metal part that is posed upon the diaphysis. The guide pin is often at the limit of the incision cut and one must apply a great deal of pressure in order to place it in exactly the right position. The presence of a burr on the deep end of the guide pin is desirable. In placing it in the right position below the vastus, then applying strong pressure upwards, it should automatically position itself and most of the time give the correct entry point for the guide pin (figure 3). A pin guide with a handle slightly inclined and X-ray transparent, allows an instant view of the correct positioning of the ancillary and the pin guide.		Figure 3 : The ideal pin guide

	Once the pin is positioned, the operation proceeds in the usual classical manner. The skin at the upper part of the incision is protected by a retractor during the passage of the bone drill. The axial screw should be put in place with an extension. (Figure 4).		Figure 4 : Screw and extension in place. The extension is placed just at the level of the upper part of the incision.

	The plaque is then slid onto the extension. In general the plaque seems larger than the incision cut. When it is introduced on the extension, it is, in principle, placed on the skin at the lower part of the incision (Figure 5).		Figure 5 : The plaque slides on the extension and « dives » into the incision.

	The angle of 135 that the canon makes with the plaque, forces the later to go up and then dive into the incision without difficulty. The only thing that is needed is the separation of the fascia lata and the vastus lateralis during the passage. Once applied on the diaphysis, the only thing remaining to do is to place the diaphysis screws. This does not pose any problems for the incision is very low on the femur and the plaque is in front of the eyes and easily seen. (figure 6). It is in any case an a excellent indicator of a good scar position.		Figure 6 : Once posed on the diaphysis, the only things that should be visible are the holes of the plaque. Placing the screws is now very easy.

	CONCLUSION It takes a bit of practice but this technique simplifies the placing of external sliding screw-plates. The incision cut is very tiny. (scar figure ) The access of the femur is not very destructive and less haemorrhagic. The intervention is more rapid. The operation takes place under closed surgery conditions. The continuity between the vastus lateralis and the gluteus medius rests intact.Thus leading one to assume that the secondary deplacements of the greater trochanter would be less frequent. In certain number of cases an adaptation of the ancillary should be considered. For example, in order make the surgeon’s work easier, it would be more convenient if the guide pin was X-ray transparent.		Scar figure : final aspect of the scar.