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

90 Injury and Skeletal Biomechanics

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

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,

*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

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

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

femoral neck fracture frequently is followed by an open reduction.

internal rotation and adduction.

anatomical position or achieving reduction.

The present methods for fixation of the femoral neck are two types: fixation with cancellous screws and fixation with massive implants with fixed angle.

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 small side plate.

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

Alternative implant systems. Massive implants with a fixed angle.

*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

### 92 Injury and Skeletal Biomechanics

sometimes leads to cutting of the DHS-screw through the soft cancellous bone of the femoral head with migration of the implant in proximal direction, accompanied by displacement in varus of the fracture; (3.) Increase of the percentage of aseptic necrosis with fixation with DHS, compared to the screw fixation. (4.) In the presence of osteoporosis, the compression upon the fracture, created by the DHS-screw is very weak, compared to the three cancellous screws, which fix in the head subchondrally in three different points.

Biomechanics of the Fractured Femoral Neck –

The New BDSF-Method of Positioning the Implant as a Simple Beam with an Overhanging End 93

[1] S.E. Asnis, L. Wanek-Sgaglione (1994) Intracapsular fractures of the femoral neck. Results of cannulated screw fixation. J Bone Joint Surg. 76, Vol.12, pp. 1793-1803 [2] R. Blomfeldt, H. Törnkvist, S. Ponzer, A. Söderqvist, J. Tidermark (2005) Internal fixation versus hemiarthroplasty for displaced fractures of the femoral neck in elderly patients with severe cognitive impairment. J Bone Joint Surg. Br 87-B, Vol.4, pp. 523-529 [3] J.E. Gjertsen , T. Vinje, L.B. Engesaeter, S.A. Lie, L.I. Havelin, O. Furnes, J.M. Fevang (2010) Internal screw fixation compared with bipolar hemiarthroplasty for treatment of displaced femoral neck fractures in elderly patients. J Bone Joint Surg. Am 92, pp. 619-

[4] G.L. Lu-Yao, R.B. Keller, B. Littenberg, J.E. Wennberg (1994) Outcomes after displaced fractures of the femoral neck. A meta-analysis of one hundred and six published

[5] J. Tidermark, S. Ponzer, O. Svensson, A. Söderqvist, H. Törnkvist (2003) Internal fixation compared with total hip replacement for displaced femoral neck fractures in

[6] S. Lindequist (1993) Cortical screw support in femoral neck fractures. A radiographic analysis of 87 fractures with a new mensuration teqhnique. Acta Orthop.64, Vol.3, pp.

[7] R.S. Garden (1961) Low-angle fixation in fractures of the femoral neck. J Bone Joint

[8] L. Hernefalk, K. Messner (1996) Rigid osteosynthesis decreases the late complication rate after femoral neck fracture. Archives of Orthopaedic and Trauma Surgery, 115, pp.

[9] V. Selvan, M. Oakley, A. Rangan, M. A-Lami (2004) Optimum configuration of cannulated hip screws for the fixation of intracapsular hip fractures: a biomechanical

[10] E. Walker, D. Mukherjee, A. Ogden, K. Sadasivan, J. Albright (2007) A biomechanical study of simulated femoral neck fracture fixation by cannulated screws: effects of

[11] J. Dickson (1953) The "unsolved" fracture: a protest against defeatism. J Bone Joint Surg.

[12] O. Filipov (2011) Biplane double-supported screw fixation (F-technique): a method of screw fixation at osteoporotic fractures of the femoral neck. Eur J Orthop Surg

[13] W.H. Harris (1969) Traumatic arthritis of the hip after dislocation and acetabular fractures: treatment by mold arthroplasty. An end-result study using a new method of

[14] F. Liporace, R. Gaines, C. Collinge, G. Haidukewych (2008) Results of internal fixation of Pauwels type-3 vertical femoral neck fractures. J Bone Joint Surg. Am 90, pp. 1654-9

placement angle and number of screws. Am J Orthop. 36, Vol.12, pp. 680-684

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the elderly. J Bone Joint Surg. Br 85-B, Vol.3, pp. 380-388

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*Proximal femoral locking plates*. These implants represent a modification of the traditional methods for fixation with cancellous screws, placed almost parallel in the cancellous bone of the femoral neck. Here the screws are fixed in the plate at the level of the lateral cortex, which solves the problem with the fragile lateral cortex of the greater trochanter and creates a stable construction. However it fixes the fracture statically, not allowing creation of compression, because of the locking of the screws and also lacks the sliding-phenomenon, which is helpful for the process of healing.

Intramedullary nails. In the presence of femoral neck fracture, combined with other fracture, located in a lower segment of femur, at present we use different types of intramedullary systems of the type of the reconstructive nail and PFN.

Other alternative types of implants, most of which have only historical significance, are the 130° blade-plates. Their inconvenience is that they cannot create compression as the screw systems and having at the same time imperfections with their outdated surgical technique. However, having a fixed angle the blade-plate ensure excellent fixation of the fracture regarding the varus stress and torsion and combined with one additional screw is probably the most effective method for fixation in fracture with vertical fracture line – type Pauwels III.
