- See:
-
Nail Placement and Depth
-
Cannulated Screws:
- Discussion:
- if bone is dense enough to permit stable fixation, patients treated by
percutaneous pinning have the advantage of immediate, full weight
bearing postoperatively;
- failures in percutaneous pinning include
AVN,
non-union, failure
of reduction, & late segmental collapse;
- options for treating these failures include conversion to hemiarthroplasty
or total arthroplasty
- Anatomy:
- osseous anatomy of proximal femur dictates where internal fixation
device should be placed for maximum purchase in femoral head;
- maximum bone density is found in the area where compression &
tension trabeculae coalesce in the center of the head;
- Multiple Pins: (Knowles, Moore's, Neufeld's)
- technique similar to
Cannulated Screws:
- pts w/ osteoporotic bone may not tolerate internal fixation;
- these pins are ideal in impacted fractures of the femoral neck,
since they may be inserted without fear of frx displacement;
- select point on lateral side of shaft of femur midway between anterior
& posterior cortices & 2 cm distal to bony ridge at distal edge of
greater trochanter, from which vastus lateralis takes origin;
- anatomic placement of the pins is critical;
- by placing pins parallel to each other, wt bearing will allow
compression to occur at the fracture site;
- divergent or convergent pins tend to prevent impaction;
- convergence increases incidence of nonunion;
- placement of parallel peripheral pins, close to the subchondral
bone, is considered ideal;
- peripheral pin placement in head will incr rotational stability;
- no more than three screws or pins are usually required;
- risk of pin penetration increase w/ each additional pin;
- consider placing pins into the subcondral bone of the femoral
head to ensure maximal proximal fixation;
- tips of knowles pins ideally should penetrate to w/in 0.6 cm of subcondrondral
bone to obtain maximum purchase on proximal fragment;
- nails in the superior aspect of the femoral head can inadvertently
interrupt the lateral epiphyseal vessels that supply most of blood
to the femoral head;
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The use of Ender's pins in extracapsular fractures of the hip.
Biomechanical analysis of the sliding characteristics of compression
hip screws.
Deyerle treatment for femoral neck fractures.
Treatment of intracapsular hip fractures by the Deyerle method. A
comparative review of one hundred and nineteen cases.
Internal fixation of femoral neck fractures.Two methods compared.
Function after hook-pin fixation of femoral neck fractures.
Prospective 2-year follow-up of 191 cases.
Fixation of 220 femoral neck fractures. A prospective comparison of the Rydell
nail and the LIH hook pins.
Femoral neck fractures. 121 cases treated by Knowles pinning.
Internal fixation of femoral neck fracture. No difference between the Rydell four-
flanged nail and Gouffon's pins.
Hook-pin fixation in femoral neck fractures. A two-year follow-up
study of 300 cases.
Internal fixation of femoral neck fractures. A comparative biomechanical study
of Knowles pins and 6.5-mm cancellous screws.
Why use drains
The effect of early weight-bearing on the stability of femoral neck
fractures treated with Knowles pins.
Femoral neck fractures. 165 cases treated by multiple percutaneous pinning.
Crossed pins vs parallel pins in the treatment of femoral neck fractures.
