SURGICAL GROWTH GUIDANCE
- Method
- A small plate with two screws at the growth plate
- Duration
- 15 to 20 minutes per growth plate
- Recovery time
- Sport after 2 to 3 weeks
In children and adolescents a deformity of the leg axis can often be corrected without dividing the bone. What is used for the correction is something that happens anyway: growth.
A small plate with two screws is placed on one side of the growth plate – one screw above it, one below. That side then grows more slowly while the other carries on as normal. Over months the axis straightens itself. The technical term is temporary hemiepiphysiodesis: a temporary brake on one half.
The procedure is small, and it is reversible. Once the axis is straight the metal comes out again, and the bone grows on symmetrically.
How the operation proceeds
Through an incision of about three centimetres – barely longer than the plate itself – the growth plate is reached. Under fluoroscopy the plate is laid across it and fixed with one screw above and one below. The growth plate itself is not injured; that is the decisive point, because it has to keep working.
Each growth plate takes about fifteen to twenty minutes. Depending on where the deformity sits, the work is done at the thigh bone, the shin bone or both, and with a two-sided deformity on both legs in one session.
The correction then happens by itself and takes time. How quickly depends on how much growth is left – during the pubertal growth spurt it moves along briskly, shortly before growth ends hardly at all.
A full-length standing radiograph is therefore taken every five to six months. Once the axis is straight, the metal is removed. From the operation to that point usually takes twelve to eighteen months.
When the operation is considered
The condition is enough remaining growth. Without growth nothing happens – the plate on its own does not correct, it only guides. That makes the timing more important here than in almost any other operation.
We suggest the procedure when the deformity is pronounced, increases over time or causes symptoms – and when it is clear that it will not grow out on its own. An age-appropriate leg position that is the same on both sides is not operated on but observed.
Why the timing decides the result
There are two ways to miss the moment with this procedure:
- Too late – there is then not enough growth left, and the axis no longer straightens fully. Only a corrective osteotomy remains.
- Too early, or left in place too long – the axis then tips past straight into the opposite direction. And after the metal is removed the deformity can return; that is called rebound.
Both are the reason for the close follow-up. The plate is not removed by the calendar but when the X-ray says so.
Aftercare following growth guidance
The operation itself is quickly over. The actual treatment is the months that follow – and the child hardly notices them.
Phase I (0–3 weeks): After the operation
- Usually two nights in the clinic
- Crutches for three to four days, then walking freely
- No cast and no restriction on loading – the leg may be used
- Sport after about two and a half to three weeks
Phase II (until correction): Letting it grow
- No restrictions in everyday life; sport and school as usual
- A check every five to six months with a full-length standing radiograph
- The axis straightens slowly – it only becomes visible after months
- Once the correction is reached, the date for removing the metal is agreed
Removing the implant
- A small procedure, usually as an outpatient, through the same scar
- Another break from sport of about two and a half to three weeks
- The bone then grows on symmetrically
- One check after growth has finished, to rule out a recurrence
Paediatric and adolescent orthopaedics
Specialist assessment of growth, leg axes and deformities
