The inward twisting of the femur
AP Hips the knees and feet will appear internally rotated
(2) (4)
The outward twisting of the femur
AP Hips the knees and feet will appear externally rotated
(2) (4)
The abnormal twisting of the tibia throughout growth causing the feet to turn inwards or outwards.
AP Knee and external rotation of the foot = external tibial torsion (ETT)
AP Knee and internal rotation of the foot = internal tibial torsion (ITT)
(1)
Can cause issues with gait and balance. Lots of rotational abnormalities will not require surgery and will correct themselves throughout the child's growth (1, 2) Derotational osteotomies may be require in severe cases. This includes FDRO and SMO's.
We image 2 locations on the leg to assess for femoral rotation
Femoral head and neck
Distal Femoral Condyles
We image 2 locations on the leg to assess for tibial torsion
Proximal tibia
Distal tibia and fibular
A rotational profile CT includes scans of all these areas unless stated on request (eg femur only)
All measurements are relevant to one another, therefore although preferable for legs to be as neutral as possible, scanning can be performed in any leg position. The most important thing is the patient is in the same position between each scan. If there is movement, the angles can no longer be compared and the whole scan must be repeated.
As we only need bony angles, these scans have a very low dose preset.
Link to protocol: FORCE CT-CP-605 Rotational profile and TTTG. 2023. Under review.docx
Case Examples:
Femoral Anteversion
Hip close to AP position, distal femur showing internal rotation
External tibial torsion
Case above: Imagine is proximal tibia was AP (externally rotated then the ankle would become externally rotated)
Case below: Proximal tibia AP, Distal tibia externally rotated
Idiopathic scoliosis is describes as "a spine with a previously normal alignment deforms in three planes – coronal, sagittal and most important, by rotation in the long axis of the vertebral column".
Can occur as an
infantile (from birth to three years)
juvenile (between four and the end of the ninth year) and
adolescent (commencing at or about ten years of age, or later)
Adolescent Idiopathic Scoliosis (AIS) is by far the most common in Australia
The following are generally accepted guidelines which are strongly influenced by the age, the degree of curve at presentation and the remaining growth potential.
<20°. Observations through the rapid growth phase on a six-monthly basis, or earlier review if parents think there has been a deterioration
20° - 40°. Bracing may be indicated if radiographic evidence of progression of more than 5° , or if there is 12 months or more of growth remaining. One third of curves in this range do not progress significantly either in adolescence, or in later life.
>45°. Surgery may be indicated.
Under 6 years of age
In young children, plaster jackets are applied around the trunk under a general anaesthetic to straighten the curve.. The cast stays on for between 1 and 4 months before being changed. Casting is useful in treating small, fast-growing children where a brace would be quickly outgrown, or when curves are too big to be braced (generally over 50 degrees). Casting is usually reserved for children under 6 years of age.
Scoliosis can also be caused by the following
Neuromuscular diseases effecting the muscles, nerves and spinal cord such as cerebral palsy and spinal muscle atrophy.
Congenital abnormalities such as hemivertebrae and congenital fusions
Underlying genetic syndromes such as Marfan Syndrome, Neurofibromatosis, Noonan Syndrome and many others.
Loss of spinal cord function early in life from disease or disorder, particularly injury (quadriplegia and paraplegia).
These types of scoliosis are managed on a case to case basis.
More information at: https://www.scoliosis-australia.org/about-scoliosis/types-of-scoliosis/
These scans are diagnostic but mainly used to assist in the intraoperative guidance of a spinal instrumentation surgery. Our CT is connected to equipment from Brain Lab during the patients surgery which will assist in guide the surgeons for screw placements throughout the curve.
Each CT requests will have a scanning range provided by the clinician to include the entire curve or ROI for operation (eg T2-L3)
It is important to topogram the entire spine to allow for accurate vertebral identification as we include 1 vertebral body above and below the given range (range T2-l3, scan T1-L4)
The Brain Lab recon requires all soft tissue to be included for the guidance to be accurate
Link to protocol: FORCE CT-CP-309 Pre Op Spine Brain Lab Navigation. 2023. Under review.docx
Scan Range requested: T2-L5
Scan range: T1- S1
Normal recons: To spine
Brain lab recon: Include all soft tissue
Scan Range requested: T2-L1
Scan range: T1- L2
Normal recons: To spine
Brain lab recon: Include all soft tissue