Dilative histogenesis is a surgical process of bone lengthening utilizing techniques that take advantage of their natural ability to create new bone mass and cover the existing bone deficit.
The Ilizarov technique that has been used with excellent results internationally and in Greece for more than 20 years.
It is applied to limb inequalities greater than two centimeters, congenital defects of the upper and lower limbs and other acquired causes resulting in a bone deficit.
It is, of course, very important that the Orthopedic Surgeon is experienced in the techniques of Expansion Histogenesis for its successful application.
Dr. N. Laliotis has a large number of applications of the Ilizarov technique.
Because the bone lengthening process also relies on device application, it is important to preface that the modern sophisticated systems implemented today are extremely user-friendly.
Dilative Histogenesis takes advantage of the fact that if a bone is “broken” in a controlled manner in the operating room and its ends move away from each other at a constant rate of 1 millimeter per day, then this gap comes to fill along the axis a new bone created by the body itself.
The maximum lengthening from one osteotomy should not exceed 7 cm.
Expanded histogenesis is applied to patients with:
- Hemimelia
- Congenital lack of a bone segment
- Achondroplasia (Dwarfism)
- Dyschondroplasia
- Epiphyseal Dysplasia
- Osteogenesis Imperfecta
- Blount’s disease
Also in patients who require rehabilitation after after:
Trauma and fractures with inadequate healing
Bone Infection
Polio
Osteoarthritis
Bone tumors
Contraindicated in children with osteoporosis.
The Surgical technique
The bone deficit can be treated in two ways:
By Osteo-transfer:
With osteotransfer, i.e. by placing a “device” which will support and maintain the original length of the bone as well as the gap of the bone deficit, while a healthy part of bone is transferred from one end of the gap to the other.
With Osteotomy:
By osteotomy, i.e. controlled fracture, which involves acute shortening of the bone allowing a bone deficit of up to 5 cm in the tibia and up to 7 cm in the femur.
At the same time, this bone is lengthened by performing an osteotomy. The acute shortening osteotomy may not be complete and only be done on the side that needs correction.
The surgery is completed after the external osteosynthesis device is added to the limb (leg or arm) to be lengthened.
The healing phase and the lengthening phase, by about one millimeter per day, follows this.
When the bone is lengthened the device is not removed because it is not able to support the patient’s weight until the bone remodeling of the new bone is gradually completed.
This is followed by plaster placement for temporary protection. The main post-operative emphasis is on physical rehabilitation.
There may be complications such as inflammation around the needles, transient pain, swelling, stiffness of adjacent joints, muscle weakness, damage to nerves and vessels, pseudarthrosis, early perforation and angular deformity. Through systematic monitoring by the Pediatric Orthopedic Surgeon these can be recognized and treated with drugs, physiotherapy or surgery.