bow legs, knock knees and other normal variants
TRANSCRIPT
![Page 1: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/1.jpg)
Bow Legs, Knock Knees and
Other Normal Variants
Dr David Bade
Director of Orthopaedics
Lady Cilento Children’s Hospital
![Page 2: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/2.jpg)
Normal Variants
• Symmetrical
• Improve with growth
• Large range of ‘normal’
• Coronal, axial/rotational planes in the lower
limb
• Most common referral to general paediatric
orthopaedic
• PARENTAL ANXIETY
![Page 3: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/3.jpg)
CORONAL PLANE ISSUES
![Page 4: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/4.jpg)
Knee Varus/Valgus
• Femoro-tibial alignment changes with growth
![Page 5: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/5.jpg)
![Page 6: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/6.jpg)
Maximum varus <18mo
Tachdjian’s 5th Ed
![Page 7: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/7.jpg)
Neutral by 2yo
![Page 8: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/8.jpg)
Max valgus
4yo
![Page 9: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/9.jpg)
Adult
alignment by
10 yo
![Page 10: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/10.jpg)
When does femoro-tibial alignment
become pathological?
1. Genu varum
2. Genu valgum
![Page 11: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/11.jpg)
1. Genu Varum
• Pathologic if:
– >18mo without signs of resolution
– Unilateral
– Progressive
– Pain
– Underlying medical diagnoses
• Rickets
• Renal failure
![Page 12: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/12.jpg)
1. Genu Varum
• What not to miss?
1. Infantile tibia vara (progressive proximal tibial
varus deformity)
• Treatment should begin <4yo
2. Underlying medical diagnoses
• Rickets
• Renal failure
![Page 13: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/13.jpg)
2. Genu Valgum
• Pathologic if:
– Intermalleolar distance >8cm >10yo
– Unilateral
– Progressive
– Underlying medical diagnosis
• Rickets
• Renal failure
![Page 14: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/14.jpg)
2. Genu Valgum
• What not to miss?
– Cozen phenomenon
• Progressive (and generally self-limiting) genu valgum
after proximal tibial metaphyseal greenstick with intact
lateral cortex
![Page 15: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/15.jpg)
![Page 16: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/16.jpg)
Treatment
• 8 plates
– Require referral prior to 12 F or 14 M (guided
growth requires >/= 2 years of growth remaining
for maximal effectiveness)
• Osteotomies
– Generally reserved for skeletally mature patients
![Page 17: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/17.jpg)
![Page 18: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/18.jpg)
![Page 19: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/19.jpg)
ROTATIONAL ISSUES
![Page 20: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/20.jpg)
“Intoer/Outtoer”
• Foot progression angle refers to angle foot
makes with straight line on floor
– Intoers have an internal foot progression angle
– Outtoers have an external foot progression angle
![Page 21: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/21.jpg)
![Page 22: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/22.jpg)
Why does a patient in- or outtoe?
![Page 23: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/23.jpg)
Rotational Profile
• Method of determining the cause for in- or
outtoeing
• Three components
1. Comparison of internal and external rotation
(hip)
2. Thigh-foot angle (or transmalleolar axis)
3. Heel bisector
![Page 24: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/24.jpg)
Rotational Profile
• Place patient prone, knees flexed to 90
• Check:
![Page 25: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/25.jpg)
1. Heel Bisector (N = 2/3)
![Page 26: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/26.jpg)
2. Thigh-foot Angle (N -5 IR – 20 ER)
![Page 27: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/27.jpg)
2. Transmalleolar Axis (N -10 IR – 15 ER)
![Page 28: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/28.jpg)
3. Hip Rotation (compare IR with ER)
![Page 29: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/29.jpg)
Intoeing
• Three etiologies:
1. Femur
2. Tibia
3. Foot
![Page 30: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/30.jpg)
Femur
• Femoral anteversion
– IR > ER
– Pathologic if persists >10yo
• Normal adult anteversion ~15 degrees
![Page 31: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/31.jpg)
Tibia
• Internal tibial torsion
– Thigh-foot angle < -15
– Pathologic if persists >8yo
• Normal adult torsion -5 IR – 30 ER
![Page 32: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/32.jpg)
Foot
• Metatarsus adductus
– Heel bisector > 3
– Pathological
• Associated with DDH
• Screen for DDH with U/S if <6mo and XR if > 6mo
![Page 33: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/33.jpg)
Outtoeing
• Three etiologies:
1. Femur
2. Tibia
3. Foot
![Page 34: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/34.jpg)
Femur
• Femoral retroversion
– ER > IR
– Normal adult anteversion 15
– Pathologic if
• Unilateral
• Progressive
• Associated with groin/thigh/knee pain (SUFE)
![Page 35: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/35.jpg)
Tibia
• External tibial torsion
– Thigh-foot angle > 30 ER
– The most common normal variant not to correct
– Pathologic if
• Unilateral
• Progressive
![Page 36: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/36.jpg)
Foot
• Forefoot abduction
– Heel bisector intersects medial to 2/3
– Pathologic if
• Progressive
• Associated with rigid flatfoot
![Page 37: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/37.jpg)
What needs treatment?
• Controversial!
• Considerations
– Functional limitations
– Pain/ Falls
– Cosmesis
– MTA
• straight- or reverse-last boots (non-operative, low risk)
![Page 38: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/38.jpg)
What treatment is available?
• No successful non-operative therapy
• Operative
– Femoral or tibial derotation osteotomies
![Page 39: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/39.jpg)
PESKY FEET
![Page 40: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/40.jpg)
![Page 41: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/41.jpg)
Flatfeet
• Arch develops until 8yo
• Two varieties
1. Flexible
2. Rigid
![Page 42: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/42.jpg)
Which is it, flexible or rigid?
• Heel rise
• Jack’s test
![Page 43: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/43.jpg)
Normal hindfoot valgus ~5-10 degrees
![Page 44: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/44.jpg)
Flexible flatfeet regain arch and
convert to heel varus with heel rise
![Page 45: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/45.jpg)
Flexible flatfeet regain arch with first toe
dorsiflexion (Jack’s test)
![Page 46: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/46.jpg)
Flexible Flatfeet
• Treatment
– ONLY if painful
• Semirigid medial longitudinal arch support orthotic
![Page 47: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/47.jpg)
What if the arch does not
reconstitute?
• Rigid flatfeet
![Page 48: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/48.jpg)
Rigid Flatfeet
• Differential diagnosis
1. Tarsal coalition
2. Congenital vertical talus
![Page 49: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/49.jpg)
1. Tarsal Coalition
• Abnormal connection between two tarsal
bones
– Fibrous/cartilagenous/bony
• Investigations:
– XR
– +/- CT or MRI
![Page 50: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/50.jpg)
![Page 51: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/51.jpg)
Treatment
• Immobilization
• Orthotic
• Surgical excision
![Page 52: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/52.jpg)
2. Congenital Vertical Talus
• Dorsal dislocation of navicular onto talar head
– “rocker bottom” foot
![Page 53: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/53.jpg)
![Page 54: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/54.jpg)
Summary
1. Genu Varum – Beware >2yo progressive +/- unilateral
2. Genu Valgum – Beware intramalleolar distance >8cm at 10yo
3. Intoeing – Beware DDH in MTA
4. Outtoeing – Beware SUFE
5. Flatfeet – Beware the rigid flatfoot
![Page 55: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/55.jpg)
OPSC at LCCH
• Orthopaedic Physiotherapy Screening Clinic
• Review all normal variant referrals to LCCH
• Doesn’t delay orthopaedic review or
intervention
• Allows earlier review in less hectic clinics
![Page 56: Bow Legs, Knock Knees and Other Normal Variants](https://reader030.vdocuments.mx/reader030/viewer/2022013009/61ce53e31693196bd621b737/html5/thumbnails/56.jpg)
Simple Fracture Management