This version was machine-translated from German and has not been medically reviewed. The authoritative version is the German version.
Orthopedics
6 calculators · leg length discrepancy, multiplier method, epiphysiodesis, Cobb angle
Here you will find calculators for orthopedics in childhood: the prediction of leg length discrepancy at skeletal maturity using the multiplier method (Paley 2000, table according to Mills & Nelson 2016), the timing of an epiphysiodesis using the arithmetic method (Menelaus/White) and the multiplier method, and the classification of a Cobb angle according to SOSORT 2016 and the AWMF guideline 151/002 (2023). They are intended for planning in leg length discrepancy and for classifying scoliosis. Each calculator states its formula and sources.
-
Leg length discrepancy at skeletal maturity (multiplier method)
Prognosis of leg length discrepancy according to Paley: congenital Δ × M, after growth arrest of one physis Δ + remaining growth -
Epiphysiodesis – timing
Arithmetic method (Menelaus/White: 9.5 mm/year distal femur, 6.4 mm/year proximal tibia) and multiplier method -
Cobb angle – classification
Severity per SOSORT 2016 and treatment thresholds of the AWMF guideline 151/002 (thoracic vs. thoracolumbar/lumbar) -
Amsterdam Pediatric Wrist Rules: radiography after wrist injury in children
Age and 5 findings after wrist injury (3 to 17 years) – probability of a fracture of the distal forearm, X-ray from 23 % (Slaar 2016) -
Hip ultrasound according to Graf: main group from the α angle
Assigns the α angle of the infant hip to a main group according to Graf: type I from 60°, type IIa/IIb 50–59°, below that IIc, D, III or IV – without β angle and subtypes -
Beighton Score for joint hypermobility
Five mobility tests, 0 to 9 points – indication of generalized joint hypermobility (Beighton 1973, thresholds according to the EDS classification 2017)
Frequently asked questions
How do I calculate leg length discrepancy at skeletal maturity?
The Leg Length Discrepancy at Skeletal Maturity (Multiplier Method) calculator uses the multipliers according to Paley 2000. For a congenital, proportionally growing discrepancy, Δ × M applies; after complete arrest of a growth plate, Δ + residual growth of the plate. In addition, it shows the growth reserve of the femur and tibia.
When is the right time for an epiphysiodesis?
The Epiphysiodesis – Timing calculator determines when a procedure on the distal femur, the proximal tibia or both will compensate the expected leg length discrepancy by skeletal maturity. It works according to the arithmetic method (Menelaus/White) and the multiplier method of Paley.
At what Cobb angle do treatment thresholds for scoliosis apply?
The Cobb angle – Classification calculator shows the severity grade according to SOSORT 2016 and the thresholds of the AWMF guideline 151/002 (2023): scoliosis from 10°, bracing from 25° thoracic or 20° lumbar with remaining growth, referral to a specialist center from 40°, surgery above 50° thoracic or 40° lumbar.