The bone (usually tibia or femur) is divided through a small incision (corticotomy). An internal lengthening nail (such as PRECICE) is placed inside the bone, or an external fixator frame is applied around the limb. Over the following weeks, the nail or frame is gradually adjusted to pull the bone apart at approximately 1 mm per day, and new bone forms in the gap (distraction osteogenesis). The distraction phase takes several weeks; the consolidation phase (while new bone hardens) takes months.
Leg lengthening is recommended for significant leg length discrepancy (usually greater than 3-4 cm), short stature conditions, and congenital limb deficiencies. The discrepancy may be due to growth plate damage, congenital conditions, or previous fracture.
Shoe raises (for discrepancies under 2-3 cm), epiphysiodesis (controlled growth arrest of the longer leg), and acceptance of the discrepancy.
Detailed planning with standing X-rays, bone age assessment, and predicted final discrepancy. Psychological preparation of the child and family is important. This is a prolonged treatment.
Correction of leg length discrepancy with the patient's own bone. Lengthening of 3-8 cm is routinely achievable. The new bone becomes indistinguishable from normal bone.
Prolonged treatmentExpected
The entire process takes many months (distraction plus consolidation).
Pain during distractionExpected
Daily lengthening can be uncomfortable. Managed with analgesia.
Joint stiffnessCommon
Knee or ankle stiffness from soft tissue tightening as the bone lengthens.
Pin site infectionCommon
With external fixators, pin site infections are very common and usually managed with antibiotics and pin care.
Premature consolidationUncommon
The bone may heal before sufficient length is achieved, requiring repeat surgery.
Delayed consolidationUncommon
The new bone may be slow to harden.
Nerve palsyUncommon
Stretching of nerves during lengthening, particularly the peroneal nerve.
Joint subluxationUncommon
The joint above or below may subluxate as the bone lengthens.
FractureUncommon
Through the regenerate bone.
Deep infectionUncommon
Particularly with external fixation.
Psychological impactCommon
The prolonged treatment can be challenging for children and families.
General anaesthesia for the initial surgery. Subsequent adjustments are done at home (internal nails with external magnets; external fixators with manual adjustment).
Distraction phase: four to eight weeks depending on the amount of lengthening needed. Consolidation phase: two to four months (the new bone hardens). Total treatment time: four to twelve months. Intensive physiotherapy throughout. Weight-bearing as guided by the surgeon. Return to full activity after the nail is removed or frame is taken off and the bone is fully consolidated.
Frequent X-rays and clinical reviews throughout treatment — typically every two to four weeks during distraction and monthly during consolidation.
How much can the bone be lengthened?
Typically 3-8 cm in a single lengthening. Greater amounts may require staged procedures. The rate of lengthening is approximately 1 mm per day.
Is an internal nail or external frame better?
Internal lengthening nails (like PRECICE) are more comfortable and have lower infection rates, but are not suitable for very young children whose bones are too small. External fixators remain an excellent option and allow more complex corrections.