Leg Lengthening with intramedullary (internal) nail over external fixator, LON
The nail is inserted in the leg (femur or tibia) and after the osteotomy (cut of the bone) it is fixed proximally with screws. A mono lateral external fixture is positioned spanning the osteotomy site. Lengthening is achieved distracting the external fixator and once the desired length is reached the nail is blocked distally during a small operation and the external fixator removed.
This method is quite comfortable for the patients, especially after removing the external fixator. Muscular contractures are still possible as for all other techniques. The operation is longer with respect of HEF, there is a considerable blood loss and carries the risk of fat embolism. In case of delated consolidation there is the option od compressing the new forming bone before removing the external fixator. Rarely bone graft is needed.
At the end of the treatment, when a solid consolidation of the new bone is achieved the nail is removed.
The frames can be removed earlier (around 5-7 months after surgery)
Lengthening the tibia with a nail is often associated with permanent anterior knee pain.
This method is more expensive (almost twice the cost of an external fixator even thought less expensive with respect of intramedullary extendable nails) due to the cost of the nails.
Possible risks of this procedure:
- Pin and deep bone infection (this is the worst down point and account for up to 3% of cases according to literature)
- Delayed bone consolidation needing a second procedure such as bone grafting
- Deformities needing further surgery
- Metalwork fatigue and break
- Fracture during the surgery. This complication have never been experienced by our patients but are described in the literature. This will need to stop the lengthening and deal with the fracture.
- Muscles contractures
- Neurovascular problems due to blood vassels or nerve stracchino. This complication have never been experienced by our patients but are described in the literature.