- Discussion:
- incorrect placement of pins is a common error;
- superior quadrant of femoral head should be avoided:
- this is where retinacular vessels enter, and pin penetration into this area may cause AVN;
- pins should not be placed superiorly inorder to avoid wt bearing area of femoral head;
- pins should enter anterior aspect of extra-synovial base of femoral neck;
- if pins are placed too posteriorly, they may exit thru lateral femoral neck reenter the head, disrupting vessels along neck;
- from anterior entry point, pins are directed posteromedially to engage epiphysis of femoral head;
- in grade III slip, epiphysis & metaphysis overlap only 25% of width of femoral neck, making accurate pin placement difficult;
- pin penetration:
- pin penetration may cause chondrolysis;
- two x-rays taken at 90 degrees don't necessarily r/o penetration, however, addition of oblique views should rule out penetration
- AP and Lateral Views of Screw Placement:
- type of screw:
- Biomechanical Comparison of Fully and Partially Threaded Screws for Fixation of Slipped Capital Femoral Epiphysis
- Biomechanical Study of 16-mm Threaded, 32-mm Threaded, and Fully Threaded SCFE Screw Fixation
- number of screws:
- references:
- Slip progression after in situ single screw fixation for stable slipped capital femoral epiphysis.
- In situ pinning on slipped femoral capital epipyhysis with a single cannulated screw.
- Biomechanical stability of single-screw versus two-screw fixation of an unstable slipped capital femoral epiphysis model: effect of screw position in the femoral neck.
- Biomechanical Testing of Unstable Slipped Capital Femoral Epiphysis Screw Fixation: Worth the Risk of a Second Screw?
The place of threaded pin fixation in the treatment of slipped upper femoral epiphysis.
- incorrect placement of pins is a common error;
- superior quadrant of femoral head should be avoided:
- this is where retinacular vessels enter, and pin penetration into this area may cause AVN;
- pins should not be placed superiorly inorder to avoid wt bearing area of femoral head;
- pins should enter anterior aspect of extra-synovial base of femoral neck;
- if pins are placed too posteriorly, they may exit thru lateral femoral neck reenter the head, disrupting vessels along neck;
- from anterior entry point, pins are directed posteromedially to engage epiphysis of femoral head;
- in grade III slip, epiphysis & metaphysis overlap only 25% of width of femoral neck, making accurate pin placement difficult;
- pin penetration:
- pin penetration may cause chondrolysis;
- two x-rays taken at 90 degrees don't necessarily r/o penetration, however, addition of oblique views should rule out penetration
- AP and Lateral Views of Screw Placement:
- type of screw:
- Biomechanical Comparison of Fully and Partially Threaded Screws for Fixation of Slipped Capital Femoral Epiphysis
- Biomechanical Study of 16-mm Threaded, 32-mm Threaded, and Fully Threaded SCFE Screw Fixation
- number of screws:
- references:
- Slip progression after in situ single screw fixation for stable slipped capital femoral epiphysis.
- In situ pinning on slipped femoral capital epipyhysis with a single cannulated screw.
- Biomechanical stability of single-screw versus two-screw fixation of an unstable slipped capital femoral epiphysis model: effect of screw position in the femoral neck.
- Biomechanical Testing of Unstable Slipped Capital Femoral Epiphysis Screw Fixation: Worth the Risk of a Second Screw?
The place of threaded pin fixation in the treatment of slipped upper femoral epiphysis.
Unrecognized pin penetration in slipped capital femoral epiphysis.
Screw Placement After Pinning of Slipped Capital Femoral Epiphysis: A Postoperative CT Scan Study