The V effect in PFN is a complication that causes a varus deformity, specifically a varus angulation of the femoral neck relative to the femoral shaft, occurring during the fixation of intertrochanteric femoral fractures with a Proximal Femoral Nail (PFN).
Understanding the V Effect
The V-effect is a well-recognized complication in orthopedic surgery, particularly associated with the use of intramedullary nails like the Proximal Femoral Nail (PFN) for repairing certain types of hip fractures.
- Iatrogenic Complication: This means the complication is caused by the medical treatment or procedure itself, in this case, the surgical fixation using a PFN.
- Procedure: It occurs during the fixation of Intertrochanteric Femoral Fractures (ITFF), which are breaks in the upper part of the femur (thigh bone) near the hip joint.
- Fixation Device: The V-effect is specifically linked to the use of a Proximal Femoral Nail (PFN), an implant inserted into the bone marrow cavity of the femur.
The Deformity: Varus Angulation
The core characteristic of the V-effect is the resulting deformity. It causes a varus of the femoral neck relative to the femoral shaft.
- Varus: In orthopedic terms, varus refers to an angulation where the distal part of a limb or bone segment is angled inward (towards the midline of the body) relative to the proximal part.
- Femoral Neck vs. Shaft: The V-effect means the angle between the femoral neck (which connects to the hip joint) and the femoral shaft (the main long part of the thigh bone) becomes abnormally decreased, causing the neck to point more downwards and inwards. This resembles the shape of the letter 'V' when viewed in certain planes, hence the name.
Clinical Significance
The V-effect is not just a radiographic observation; it has significant clinical implications.
- Rate: It is observed at a "considerable rate," meaning it is not uncommon.
- Importance: It is highlighted as an "important complication."
- Outcome: The V-effect is associated with a "high re-operation rate," indicating that it often requires further surgery to correct the deformity, address persistent pain, or manage implant failure resulting from the biomechanical changes caused by the angulation.
Summary of V Effect
| Aspect | Description |
|---|---|
| Definition | Iatrogenic complication during PFN fixation of ITFF |
| Cause | Associated with Proximal Femoral Nail (PFN) usage |
| Resulting Deformity | Varus angulation of the femoral neck relative to the femoral shaft |
| Significance | Occurs frequently, important complication, high re-operation rate |
Preventing or minimizing the V-effect is a key goal during surgical planning and execution when treating intertrochanteric fractures with a PFN. Careful technique, implant selection, and positioning are crucial factors in trying to avoid this undesirable outcome.
