01Core principlesThe concepts and mechanisms needed to understand the subject.
Fracture interpretation begins before the cortex is inspected. The study must belong to the correct patient and side, use projections capable of demonstrating the suspected injury, and cover enough anatomy to assess adjacent joints. A single view converts a three-dimensional injury into overlapping shadows; apparent alignment can therefore be false reassurance. Mechanism and maximal tenderness guide which region and special views are needed.
A disciplined search separates detection from description. First assess overall alignment and joint congruence. Then trace each cortex and medullary contour, inspect trabeculae and articular surfaces, and compare paired bones. Review cartilage spaces, growth plates and soft tissues. Once a fracture is found, deliberately continue: the second injury, dislocation, foreign body or complication often changes urgency more than the first fracture.
Description should allow another clinician to reconstruct the injury. Name the bone and exact segment, orientation and completeness of the line, fragment number, displacement by direction and proportion, angulation by apex, shortening, rotation and articular involvement. In children state physeal and epiphyseal involvement. In prosthetic bone describe the relationship to components and signs of loosening without claiming stability from one projection.
Key points
- Confirm patient, side, date, mechanism and clinical question, then assess projection, exposure, motion, collimation and whether two adequate orthogonal views include the required joints.
- Use a fixed sequence through alignment, bones, cartilage and joints, then soft tissues; trace every cortex rather than stopping at the first abnormality.
- Describe site, bone segment, fracture line, displacement, angulation, shortening, rotation, comminution, articular extension and whether the physis or prosthesis is involved.
- Judge joint congruence and alignment lines above and below the injury because a visible fracture may be part of a fracture-dislocation or paired-bone injury.
- Treat lipohaemarthrosis, displaced fat pads, focal swelling and joint effusion as indirect signs that can justify targeted additional imaging.
- End with an impression that answers the question, names technical limits, highlights urgent complications and recommends only a next test that will change care.
02Mechanisms and patternsImportant relationships and how to distinguish them.
A sharp lucency, step or buckle interrupts the expected cortex; trace it on an orthogonal view and distinguish a fracture from a nutrient canal or unfused ossification centre.
Loss of a normal joint line, unexpected overlap or disruption of anatomical alignment may reveal dislocation, subluxation or a subtle fracture even when no line is obvious.
Report fragment translation, shortening and rotation separately; describe angulation by the direction of the distal fragment or the apex according to local convention.
A fracture entering a joint requires assessment of step, gap, congruence and associated impaction because these influence stability and operative planning.
Fat-pad displacement, lipohaemarthrosis, focal swelling and periosteal reaction can signal an occult or healing injury but remain anatomical clues rather than diagnoses alone.
After finding one fracture, inspect adjacent joints and the entire paired bone for patterns such as Monteggia, Galeazzi, Lisfranc or fracture-dislocation.
03Interpreting evidenceInformation, measurements and their limitations.
Consider the information, its meaning and its limitations before deciding what follows.
- 01
Orthogonal radiographs - Why
- Demonstrate the injured bone and adjacent joint in at least two perpendicular planes.
- Interpretation and limitations
- If one projection is absent, rotated or does not include the painful region, fracture displacement and joint congruence cannot be judged reliably.
- 02
Targeted special views - Why
- Profile anatomy hidden on standard projections, such as scaphoid, mortise, axial shoulder or oblique foot views.
- Interpretation and limitations
- The requested view must follow mechanism and examination; extra projections do not compensate for imaging the wrong region.
- 03
Computed tomography - Why
- Define complex, intra-articular, pelvic, spinal or anatomically overlapping fractures and assist operative planning.
- Interpretation and limitations
- CT improves cortical and geometric detail but does not replace immediate limb assessment or reliably exclude all marrow-predominant injury.
- 04
Magnetic resonance imaging - Why
- Detect radiographically occult fracture, marrow oedema and associated ligament, cartilage or tendon injury.
- Interpretation and limitations
- MRI is sensitive but should be targeted to a clinical question; incidental signal changes require correlation with symptoms and mechanism.
- 05
Comparison imaging - Why
- Distinguish chronic deformity, accessory ossification and postoperative appearances from acute change.
- Interpretation and limitations
- Comparison helps only when projection and clinical interval are considered; bilateral imaging is not a routine substitute for expertise.
04Applied reasoningWorked examples connecting principles to decisions.
01Worked caseVerify and searchA new trauma radiograph is available for clinical interpretation.+
- 1Context: match identity, side, date and mechanism, then decide whether coverage and projections can answer the referral question.
- 2Reasoning: inspect alignment before tracing every cortex, medulla, joint surface and surrounding soft tissue in a fixed order.
- 3Outcome: describe each abnormality using site, morphology, displacement and articular or physeal involvement.
- 4Verification: state the impression, confidence, urgent implication and any focused next test or view that changes management.
02Second injuryContinue after detectionA fracture or dislocation has already been identified on the image.+
- 1Return to the start of the search pattern rather than ending interpretation at the first lesion.
- 2Trace the full involved bone and paired bone and assess joints proximal and distal to the visible injury.
- 3Look for neurovascular-risk patterns, open injury clues, foreign material and soft-tissue gas or swelling.
- 4Communicate any additional unstable pattern and ensure the patient is re-examined with the imaging findings.
03Limited studyResolve discordance safelyRadiographs are normal or equivocal but examination and mechanism still suggest important injury.+
- 1Recheck the exact site of tenderness and whether the imaged field and projection cover that structure.
- 2Review for subtle cortical, trabecular, alignment and soft-tissue signs with an experienced reader.
- 3Immobilise or restrict weight bearing when clinically appropriate and select CT or MRI by the suspected structure.
- 4Assign follow-up ownership and give deterioration advice instead of treating the initial film as definitive exclusion.
05Checking understandingVerify the reasoning, revisit uncertainties and apply feedback.
- Repeat and document distal pulse, perfusion, motor and sensory findings after splintage, manipulation or any clinical change.
- Confirm that the final report and images have been reviewed together when management depends on alignment or an associated lesion.
- Track requested additional views or cross-sectional imaging to completion, including who will act on the result.
- At follow-up, compare alignment and healing on matched projections and relate appearances to pain, function and weight-bearing status.
- Escalate a discrepancy between the preliminary and final report through the local communication process and reassess the patient.
06Special situationsVariants, exceptions and circumstances that change the usual approach.
One view is one shadow
A fracture aligned with the beam can disappear, while displacement may be underestimated when the second plane is missing.
Describe before classifying
An exact plain-language account remains useful even when an eponym or formal classification is uncertain or has imperfect reliability.
Cartilage is invisible
Joint-space width and ossification centres are indirect markers; unossified paediatric epiphyses and cartilage can conceal major injury.
Check the edge
Clinically important abnormalities often lie at image margins, including an adjacent dislocation or fracture just beyond tight collimation.
Swelling has geography
Focal soft-tissue swelling can direct attention to a subtle fracture, but diffuse swelling alone cannot prove a bony lesion.
Clinical status leads urgency
Imaging detail refines anatomy, whereas perfusion, skin threat, open wounds and compartment findings determine immediate limb-saving action.
07Common pitfallsFrequent interpretation and management errors.
- 01
Accepting a single projection as proof of normal alignment.
- 02
Using only an eponym without describing the actual injury.
- 03
Stopping once the first fracture has been seen.
- 04
Failing to compare imaging with the point of maximal tenderness.
- 05
Delaying emergency care while pursuing technically perfect radiographs.