**6. Unusual and difficult cases**

Difficult for management are the unstable fractures and the fractures with vertical fracture line Pauwels type III.

*Unstable fractures*. In the elderly patients, at the age above 80, the preoperative reduction is usually achieved easily because of the fact that the fracture occurs upon low-energy trauma and although it seems displaced at a diagnostic X-rays (Garden III and IV), the fracture is usually stable and in the process of reduction there is a good control over the head fragment.

In younger and active patients the fracture usually occurs with more severe traumatic influence, for example falling over slippery surface, falling from a greater height (from stairway or in road accidents). In these cases more severely expressed tearing of soft tissues around the fracture occurs frequently and the fracture is severely displaced. Following the incident some patients try to get up and step on the limb, thus causing additional displacement of the fracture or additional fragmentation, which turns one banal fracture of the femoral neck into a an unstable fracture. When there is a severe displacement of the fracture, clinically the patients are with more expressed external rotation and shortening of the limb and have a history of more severe traumatic influence, or patients report for attempts of getting up and stepping, followed by repeated falling. At a diagnostic X-ray the usually registered grade according to Garden is type ІV+ with severe external rotation of the distal fragment. In these cases frequently is found that the distal fragment "hangs" at the fracture table on the lateral view under its own limb weight. In such cases the reduction and fixation can turn to be extremely difficult and a doubtful prognosis of the femoral head survival can be assessed. It is reasonable in such patients if they are not at a young age a decision to be made for a primary joint replacement. In the presence of contraindications for joint replacement, if, nevertheless, a decision is made for metal fixation, we try the usual preoperative reduction: traction, abduction and internal rotation or sometimes a reposition by Leadbetter. If the preoperative reduction is not successful, we use frequently the intraoperative reduction, as under the conditions of sterility, the hanging distal fragment is lifted by the surgical assistant or by a special attachment of the fracture table. With achieving of reduction we use the guiding wires for temporary fixation of the fracture, followed by screw fixation. The intraoperative reduction is a procedure with a high risk for failure and the beginning of the surgery without a successful preoperative reduction of the femoral neck fracture frequently is followed by an open reduction.

Biomechanics of the Fractured Femoral Neck –

The New BDSF-Method of Positioning the Implant as a Simple Beam with an Overhanging End 91

good fixation is achieved with the 130º blade-plate, placed low in the distal one-third of the femoral neck. In order to be avoided fracture displacement during the placing of the blade of the plate, I recommend, following placing of the guiding wire for the blade of the plate, to be performed preliminary fixation of the fracture with one cannulated 7.3 mm screw, placed in the upper one-third of the femoral neck, parallel to the guiding wire for the blade of the plate. The fixed angle of the blade of the plate successfully counteracts to the shearing forces and its double-L cross-section counteracts to the torsion forces until reaching of healing. An alternative technique is a valgus accomplishing osteotomy at the level of lesser trochanter, with fracture surface placed into more horizontal plane and shearing forces turned into compressive. The fixation is with a DHS-plate or with 130º blade-plate. For the Pauwels type

The present methods for fixation of the femoral neck are two types: fixation with cancellous

Methods for fixation of the femoral neck with cancellous screws. At present different methods for screw fixation are used, with typical for the conventional methods placement of the screws parallel to each other and parallel to the axis of the femoral neck. The most popular are the methods with three parallel screws, placed in a configuration of a triangle – two screws distally and one screw proximally; the inverted triangle configuration; the configuration of four parallel screws, placed with square-like form; configuration of three parallel screws, situated in one plane vertically. The main goal in all of these methods is achievement of compression between the fragments. Besides there is a striving of placing the screws with divergence in the femoral head. It is recommended the screws to be placed as far as possible in the periphery, close to the cortex, in order to be achieved maximum stability of fixation. Fixation with screws is also popular, connected with a

The presented new method of *Biplane Double-Supported Screw Fixation* of the femoral neck provides new opportunities in biomechanical and clinical regard, which surpasses all

*DHS (AMBI)-plate*. The fixation with DHS (AMBI)-plate is considered as an alternative method for screw fixation in fractures of the femoral neck. An advantage of the DHS-plate is the fixed angle, which ensures support of the femoral head in regard to the varus stress. Disadvantages of the femoral neck with DHS (AMBI-plate), especially in the presence of osteoporosis are as follow: (1.) The DHS-screw fixes the fracture only in one point and usually requires placing of one additional, antirotational screw, which severely increases the volume of metal, implanted in the femoral neck; (2.) Upon loading, the 135-degree DHS implant not always ensures effective sliding-phenomenon, and with severe osteoporosis the body weight loading

ІІІ fractures in the present are used successfully *locking plates.* 

screws and fixation with massive implants with fixed angle.

known up to now methods of screw fixation for this fracture.

Alternative implant systems. Massive implants with a fixed angle.

small side plate.

**7. Other popular methods for fixation of the femoral neck** 

There exists a group of *unstable* fractures, with which the proximal fragment is too rotated and stands in valgus position, with fracture surface directed laterally. A frequent cause for this is the V-shaped fracture surface with presence of a spicule, which is obstructive to the reduction. If after an attempt for reduction on the fracture table by abduction, traction and internal rotation, the fracture reduction remains unsatisfactory, we apply a developed by the author method for reduction by traction, abduction, external rotation, release of traction, internal rotation and adduction.

*Filipov's technique*: The traction is increased, the limb is abducted and externally rotated in order to wedge away the fragments of the vicious position; next a complete release of the traction is applied and thus the distal fragment skips the obstacle and comes into contact with the head fragment placed in valgus in a new mode. Then internal rotation is applied and adduction of the limb, with the distal fragment reaching the head fragment in anatomical position or achieving reduction.

Sometimes the unstable fractures of the femoral head require open reduction.

The fractures with vertical fracture line (*Pauwels type ІІІ*) are difficult for metal fixation. If the patient is with contraindications for primary joint replacement (young age) and it however requires metal fixation, the popular method of choice are the implants with fixed angle [14]. In these fractures the curve of the femoral neck distal cortex is included to the proximal fragment and it makes inefficient the fixation with screws alone. In vertical fracture line a good fixation is achieved with the 130º blade-plate, placed low in the distal one-third of the femoral neck. In order to be avoided fracture displacement during the placing of the blade of the plate, I recommend, following placing of the guiding wire for the blade of the plate, to be performed preliminary fixation of the fracture with one cannulated 7.3 mm screw, placed in the upper one-third of the femoral neck, parallel to the guiding wire for the blade of the plate. The fixed angle of the blade of the plate successfully counteracts to the shearing forces and its double-L cross-section counteracts to the torsion forces until reaching of healing. An alternative technique is a valgus accomplishing osteotomy at the level of lesser trochanter, with fracture surface placed into more horizontal plane and shearing forces turned into compressive. The fixation is with a DHS-plate or with 130º blade-plate. For the Pauwels type ІІІ fractures in the present are used successfully *locking plates.* 
