Orthopedics: Trauma, Elective Reconstruction and the Next Best Step
Scope of the domain
The Orthopedics domain of the OMSB specialty examination tests decision-making across trauma, pediatric orthopedics, hand and peripheral nerve injury, arthroplasty and its complications, sports and soft-tissue injury, musculoskeletal oncology, and core basic science (bone healing, biomechanics, implant behaviour). Questions favour the next best step and the complication you must not miss.
Rules that decide marks
- Open fractures are graded Gustilo-Anderson I–IIIC; the grade sets antibiotics, debridement urgency and soft-tissue coverage. Antibiotics within one hour and tetanus status matter alongside timely debridement.
- Compartment syndrome is a clinical diagnosis: pain out of proportion, a tense compartment, and pain on passive stretch. Pulselessness is a late sign; fasciotomy is the treatment, and compartment pressure measurement only supports the decision (a delta pressure under 30 mmHg is concerning).
- An undisplaced scaphoid waist fracture may not appear on the first radiograph: immobilise and reimage (or proceed to CT/MRI), because nonunion and proximal-pole avascular necrosis are the feared outcomes.
- In the elderly, a displaced intracapsular hip fracture is treated with arthroplasty and surgery should not be delayed; subtrochanteric fractures need a cephalomedullary device.
- Chronic prosthetic joint infection (over 4 weeks, loose implant) needs implant removal and two-stage revision; an acute infection with a stable implant is the setting for debridement, antibiotics and implant retention.
Worked example
A 7-year-old falls from a wall and holds the elbow flexed. The elbow is swollen, the radial pulse is palpable, capillary refill is brisk, and radiographs show a Gartland III supracondylar fracture. Reasoning: the hand is perfused, so the priority is urgent closed reduction and percutaneous pinning in theatre, then reassessment of the pulse; vascular exploration is reserved for a still-absent pulse after reduction or a white, cool hand. Median (anterior interosseous) nerve function is documented before and after.
Traps
Waiting for a pulseless limb before diagnosing compartment syndrome; exploring a pink hand before reducing the fracture; treating a normal first scaphoid film as exclusion; forgetting the ipsilateral femoral neck in a shaft fracture; and calling a physeal injury a sprain.