Fracture & Musculoskeletal Classification
Every fracture & musculoskeletal classification calculator on CalcEngines — unit converters, derived indices and interpretive tools, each with its formula, a worked example and the reference intervals it is judged against.
16 calculators in this section
- Acetabular Index Calculator (Tonnis Angle)The acetabular index from Hilgenreiner's line, with the two age-band thresholds a source states in text — and a plain statement that this page holds no centile table, because Tonnis's age norms exist only as a picture.
- Bohler Angle Calculator (Calcaneus)Bohler's tuber joint angle from the two drops it is built out of, with the three published normal ranges that disagree about where it starts — and the 76-degree spread between experienced readers measuring the same fractured heel.
- Cobb Angle Calculator (Scoliosis)The Cobb angle from the two endplate inclinations, and the change from a previous film read against the published measurement error — because a difference under 10 degrees is not progression.
- Compartment Differential Pressure CalculatorDiastolic blood pressure minus intracompartmental pressure, with the mean-arterial variant alongside it — and the published evidence that this number rules acute compartment syndrome OUT far better than it rules it in.
- Garden Classification of Femoral Neck FractureStage an intracapsular femoral neck fracture I to IV from completeness and displacement — and see why the four grades agree so poorly between observers that most practice collapses them to two.
- Gustilo-Anderson Open Fracture ClassificationGrade an open fracture I to IIIC from the wound, the energy and the soft-tissue coverage — with the published infection rates and the cohorts they came from, and the reason the grade belongs to the operating theatre rather than the emergency department.
- Hip-Knee-Ankle Angle Calculator (Mechanical Axis)Coronal mechanical alignment from two offsets and two lengths, in both published conventions — with the 4.84 degrees of measurement error that limb rotation alone introduces, and the third of men who are constitutionally varus.
- Lateral Centre-Edge Angle Calculator (Wiberg)Wiberg's lateral centre-edge angle from the two distances that define it, with Hanson's published thresholds — and the 4 degrees that separate the bony rim from the sourcil, which reclassified ten of fourteen dysplastic hips.
- Neer Proximal Humerus Fracture ClassificationCount the displaced segments to get a one-, two-, three- or four-part fracture — then read the published kappas, which run from 0.03 to 0.57 and include an observer agreeing with themselves at 0.20.
- Ottawa Ankle and Foot Rules InterpreterApply both Ottawa rules to an acute ankle injury, with the exclusions that define the population they were validated in — and the predictive values worked out from the published 2x2 tables, because near-perfect sensitivity and 25 to 49% specificity is the whole story.
- Patellar Height: Insall-Salvati Ratio CalculatorDivide the patellar tendon length by the patellar length for the Insall-Salvati ratio, with the modified ratio alongside it — and two published sets of cut-offs that disagree about where patella alta begins.
- Pauwels Angle Calculator (Femoral Neck)The inclination of a femoral neck fracture line, with Pauwels' three types — and the published verdict that the reference horizontal "can only be arbitrarily assigned" and the types predict neither non-union nor avascular necrosis.
- Posterior Tibial Slope CalculatorPosterior tibial slope by Bernhardson's published method — 90 degrees minus the plateau-to-axis angle — for the medial and lateral plateaus separately, with the cohort means and the 12-degree figure two sources give.
- Salter-Harris Classification InterpreterType a physeal fracture I to V from which structures the line crosses — with the published growth-disturbance rates by type, the zone of the physis each type passes through, and why the mnemonic teaches the anatomy and not the prognosis.
- Sharp Angle Calculator (Acetabular Inclination)Sharp's angle from the inter-teardrop line, with his own 1961 bands in 200 hips — and the three different upper limits that four sources put at 42, 43, 45 and 47 degrees.
- Weber Ankle Fracture ClassificationClassify an ankle fracture Weber A, B or C from the level of the fibular fracture — and see why a system built on bone is being used to report a ligament that the radiograph cannot show.