Introduction: Angular deformities around the knee; Genu Varum (Bowing) or Genu Valgum (Knock knees) are commonly seen deformities in children. These can be physiological as well as pathological. The newborns have a physiological genu varum which is highest around age of 1 yr. and later as the child grows the lower limbs become straight and then further progress to Valgus between age of 3-4 years. It reaches normal angulation of 7-10 degrees by the age of 7 yrs.
Causes of Bowing/ Knock Knees
Physiological
If the Genu Varum persists beyond 2 years, it is considered pathological.
Pathological: Few causes are listed below:
| Genu Varum | Genu Valgum |
| Vit D deficiency Rickets | Vit D Deficiency Rickets |
| Hypophosphataemic Rickets | Renal osteodystrophy |
| Blounts Disease | Dysplasias |
| Syndromes: Ellis Van Creveld, MPS | Syndromes: MPS, Achondroplasia |
| Physeal injury: Trauma, Infection | Physeal Injury |
| Tumours: Osteochondroma, Fibrous dysplasia |
Investigations: Blood Investigations: Vit D3, Sr Phosphorous, Alkaline Phosphatase, Sr. Calcium, Renal Workup Radiology: Full Length Scanogram, Physeal bar Maping on MRI for Physeal injuries
Medical Treatment: Mainly for Vit D deficiency Rickets, Hypophosphataemic rickets, Renal Osteodystrohy
Bracing: Limited Role – Blount’s Disease A three-point brace customized as per the child can be used to correct the deformity.
Growth Modulation: Also known as hemiepiphysiodesis, is a lesser invasive procedure which involves application of Clips/Bone Staples or Plates on distal femoral physis or proximal tibial physis to control the growth at the Growth plate and thereby correct the deformity gradually. The growth modulation corrects deformities at an average rate of 0.7 to 1.2 degrees per month. The advantage of this procedure is early recovery, no immobilization in plaster and child can regain regular activities within a week.
Osteotomy: Indicated in skeletally mature children. This is a more invasive procedure which requires correction of deformity acutely at the distal femur or proximal tibia and removing a wedge (Part of bone depending on the degree of deformity) and fixation with a larger plate and screw system or an external fixator. This procedure requires more rehabilitation, longer period of rest and non-weight bearing.
Conclusion: Genu Varum and Genu Valgum are common deformities around the knee in Children. They need to be addressed so as to maintain alignment and prevent arthritis and injuries in future. Also, this malalignment can interfere with normal walking, running and sports activities in the children. Timely intervention in terms of investigation and diagnosing the cause and further treatment is important.