Guided growth is often described as a small operation. Surgically, it can be: a plate is placed across one side of the growth plate through small incisions. For families, however, the less obvious part comes afterwards.
The child's legs are still bowed or knock-kneed after the operation. The plate does not straighten the bone immediately. It temporarily changes growth on one side of the growth plate, allowing the remaining growth to gradually correct the alignment.
The outcome therefore depends on time and follow-up appointments, as well as the operation itself.
Why the leg is not straight immediately after surgery
Temporary hemiepiphysiodesis with a tension-band plate, often called an eight-plate, slows growth on one side of the growth plate while the other side continues to grow. Alignment changes gradually over the following months.
The rate varies between children. It depends on age, the growth plate treated, remaining growth, the cause of the deformity and its initial severity. A systematic review reported average correction rates of roughly one degree per month, with considerable variation; more recent studies also suggest faster correction in children with more growth remaining. [1,2]
That is why I do not promise a precise correction date based on the first X-ray alone.
The first few days: walking and everyday activities
Early recovery is generally much quicker than after an osteotomy, because the bone has not been cut to change its alignment immediately. Nevertheless, pain, swelling and difficulty fully bending the knee can occur in the first few days.
Advice about weight-bearing, crutches, school and activity depends on the site treated, the technique and the individual child. There is no timetable that suits everyone. The key distinction is that wound healing and movement recover over weeks, whereas alignment changes over months.
Why X-rays are needed even when the child feels well
Follow-up appointments now have a different purpose.
A child may have no pain and move comfortably while correction continues. Follow-up is therefore about more than checking whether the plate causes discomfort. It measures alignment and shows how growth is changing the femur and tibia.
Waiting until overcorrection becomes visible means relying on a late sign. Standing full-length lower-limb X-rays allow the team to assess the mechanical axis and joint angles, and plan when to stop guiding growth.
When is the plate removed?
The plate is intended to be temporary. It is removed when the desired correction has been achieved, or when the surgeon considers removal appropriate in relation to the remaining growth.
There is no universal threshold for every child. Timing aims to avoid removing it too early and leaving a residual deformity, or waiting too long and allowing overcorrection.
A 2024 review highlights the need to individualise both the expected correction rate and the timing of removal. [3]
Can the deformity return after removal?
Once the plate is removed, the growth plate may resume more symmetrical growth. In some children, however, part of the deformity returns. This is called rebound.
Rebound does not necessarily mean that the operation was performed incorrectly. It reflects the behaviour of the remaining growth and appears more common in younger children and after rapid correction. In one study, correction faster than about 7° per year was associated with a higher rebound risk. Other studies have identified age, the tibial site and underlying conditions as relevant factors. [4,5]
This explains why follow-up sometimes continues after the plate has been removed.
Sport while the plate is in place
Having an eight-plate is not the same as having a fracture, and does not mean the child must remain inactive throughout the months needed for correction. After the wound has healed and movement and strength have recovered, return to activity depends on the clinical assessment and the surgeon's instructions.
The period immediately after surgery, and the period after implant removal, each require specific advice. Between appointments, the aim is to allow everyday life to continue as normally as possible while alignment gradually changes.
Follow-up determines when to stop guiding growth
Guided growth relies on something that will eventually run out: the child's remaining growth.
That makes follow-up part of the treatment itself. Appointments help determine whether the plate should remain in place, when it should be removed and how long monitoring should continue afterwards.
Removal is therefore not scheduled solely according to the months since surgery. The correction achieved, remaining growth and findings at follow-up determine when to stop growth modulation.
References
[1] Kumar S, Sonanis SV. Growth modulation for coronal deformity correction by using Eight Plates-Systematic review. Journal of orthopaedics. 2018. PubMed: 29657461 · DOI.
[2] Salvato D, Chipman DE, Cirrincione P, Hawes J, Lijesen E, Green DW. Temporary hemi-epiphysiodesis with tension band plates in skeletally immature patients with genu valgum: Faster correction in patients with more than 2 years of expected time of growth remaining. Journal of children's orthopaedics. 2024. PubMed: 39100981 · DOI.
[3] Zeng JF, Xie YY, Liu C, Song ZQ, Xu Z, Tang ZW, Wen J, Xiao S. Effective time, correction speed and termination time of hemi-epiphysiodesis in children. World journal of orthopedics. 2024. PubMed: 38293262 · DOI.
[4] Choi KJ, Lee S, Park MS, Sung KH. Rebound phenomenon and its risk factors after hemiepiphysiodesis using tension band plate in children with coronal angular deformity. BMC musculoskeletal disorders. 2022. PubMed: 35395849 · DOI.
[5] Zaidman M, Kotlarsky P, Eidelman M. Rebound predictors of varus-valgus deformities around the knee corrected by guided growth. European journal of orthopaedic surgery & traumatology : orthopedie traumatologie. 2023. PubMed: 35119489 · DOI.
Disclaimer: this article provides general information. Weight-bearing, follow-up, sport and implant removal must be planned by the surgeon for the individual child.
Related information
The procedure is explained in guided growth and epiphysiodesis. For the clinical background, see knock-knees and bow legs.
After an isolated procedure around the knee, the guided-growth rehabilitation pathway provides illustrated options for the treating clinician to select. It does not replace individual postoperative instructions or growth monitoring.
