This document discusses genu valgum, or knock knees. It defines the deformity as an outward deviation of the longitudinal axis of the tibia. Genu valgum results in the medial angulation of the knee and external rotation of the femur and tibia. It can be caused by physiological, pathological, traumatic or metabolic factors that create asymmetric growth of the epiphyseal plate. Treatment involves conservative measures like bracing or surgical options like osteotomies if the deformity is severe.

1. GENU VALGUS
Dr. Santosh Batajoo

2.  Genu valgum or knock knee
 Outward deviation of the longitudinal
axis of tibia.

3. DEFORMITY
 Medial angulation of the knee and outward
deviation of the longitudinal axis of both the tibia
and the femur.
 Advanced cases- the distal ends of the femur
and tibia are rotated externally by the pull of the
biceps femoris and the tensor fascia lata.
 Distal shaft of the tibia develops a
compensatory internal rotation
 Pronated and flat foot.

4.  Idiopathic variety is the commonest.
 Bilateral
 Physiological genu valgum appears at the
age of 2-3 years and nearly always corrects
by the age of 6.

5. PATHOPHYSIOLOGY
 The mechanical axis shifts
laterally, pathologic stress is
placed on the lateral femur and
tibia, inhibiting growth and
possibly leading to vicious cycle.

6.  Asymmetrical rate of growth of the
epiphyseal plate- trauma, infection.
 Static abnormality like deformed femur or the
tibia or muscle imbalance brings excessive
pressure on one end of the plate.
 Metabolic and nutritional disturbance
 Malunion of fracture at the metaphysis
 Developmental disturbances – osteogenesis
imperfecta, chondrodysplasia

7.  The medial condyle assumes larger proportions,
and the articular surfaces lie at an oblique
angle.
 The quadriceps extensor mechanism crosses
the joint over the lateral aspect where the
patella tends to subluxate or dislocate outward.
 Soft tissue structures on the lateral side are
shortened (biceps, iliotibial band, peroneal
nerve)
 Medial collateral ligament is lax.

8. TYPES
Physiological –
Compensatory-
 Varus, valgus and rotational deformities
of the proximal femur.
 Persistent anteversion of the femoral
neck
Pathological-
 Distorted epiphyseal or physeal growth.
 Rickets, injuries of the epiphyseal and
physeal growth cartilage.

9. In adults-
 Common in females.
 May be sequel to childhood deformity,
rheumatoid arthritis, ligament injury,
malunited fractures, paget’s disease.
 Complications-
 Patello-femoral osteoarthritis due to
abnormal tracking of the patella.

10. CAUSES
 Idiopathic
 Post-traumatic
fractures of the lateral femoral or tibial condyles
damage to lateral lower femoral or upper tibial
epiphyses.
 Post inflammatory
damage to lateral epiphyses by infection.
 Neoplastic
tumour causing growth disparity e.g.
chondroblastoma

11.  Bone softening
rickets and osteomalacia, bone dysplasias,
RA
 Stretching of joints
charcot’s disease, paralytic disease
 Cartilage thinning
OA of the lateral compartment of the knee

12. CLINICAL FEATURES
 Knee pain
 Gait- limp or circumduction
 Deformity of the knee.
 Intermalleolar gap- distance between the medial
malleoli when the knees are touching with the
patella facing forwards, is more than 8cm.

13.  Plumb line test.
 Knee flexion test to detect whether it lies in
the femur or tibia.

14. RADIOGRAPHS
X-ray
 Entire lower limb with the
patient weight bearing
 Angle formed between
femoral and tibial shafts
(normal 6º)

15.  Lateral distal femoral angle (normal - 84º)
 Proximal medial tibial angle (normal – 87º)

16. TREATMENT
CONSERVATIVE-
 Depends on the cause.
 vitamin D and calcium supplements
 Weight loss
 Exercise

17.  Pronation of the feet is corrected by elevating
the inner border of the shoes
 Knock knee braces are worn continuously

18. SURGICAL-
 More severe cases- intermalleolar distance
more than 10cm by the age 4.
 If the lateral portion of the
epiphyseal plate is intact-
stapling the medial portion
of the epiphyseal plate.
 If correction is achieved before growth is
complete, some overcorrection must be
attained.

19. Open wedge osteotomy-
 After epiphyseal fusion- an osteotomy at the site
of maximum deformity, either femur or the tibia.
 If the length of the extremity is adequate, a
wedge of bone is removed from the medial side.
 If the length is short, osteotomy from the outer
side lengthens the extremity.

20. THANK YOU…