Orthopaedics — 5-min cram sheet
_Built from the ortho disease index. Deck-faithful._
Buzzword → answer (the vignette reflex)
- Dinner-fork deformity / FOOSH with wrist EXTENDED → Colles' fracture (distal radius, DORSAL angulation, extra-articular)
- Garden-spade deformity / fall onto FLEXED wrist → Smith's fracture (distal radius, VOLAR angulation)
- Anatomic snuffbox tenderness + FOOSH → Scaphoid fracture (retrograde supply → AVN/non-union; more proximal # = higher risk)
- Pain OUT OF PROPORTION + pain on PASSIVE stretch → Compartment syndrome (emergency fasciotomy)
- Crescent sign on X-ray → Osteonecrosis / AVN (earliest X-ray sign; MRI = gold standard)
- Saddle anaesthesia + BILATERAL sciatica + bowel/bladder incontinence → Cauda equina syndrome (emergency; MRI)
- Bone pain WORSE AT NIGHT, relieved by salicylates → Osteoid osteoma
- Distal 1/3 humeral SPIRAL # + wrist/finger drop → Holstein-Lewis (radial nerve at risk)
- Simmonds'/Thompson's +ve (squeeze calf, no plantarflexion) → Achilles rupture
- Finkelstein +ve / radial-sided wrist pain → De Quervain's tenosynovitis (1st dorsal extensor compartment)
- Tinel's/Phalen's +ve, numb radial 3½ digits, thenar wasting → Carpal tunnel syndrome (median nerve)
- Kanavel's 4 signs → Pyogenic flexor tenosynovitis
- Prominent acromion + empty glenoid, arm held in external rotation → Anterior shoulder dislocation (check AXILLARY nerve)
- 'Lover's fracture' — heel pain after fall from height → Calcaneus fracture (CT essential)
- Sequestrum + involucrum → (Haematogenous) osteomyelitis — pathological hallmarks
- Sunburst periosteal reaction → Osteosarcoma
Fracture eponym / sign → injury
| Eponym / sign / X-ray clue | Injury / diagnosis (index wording) |
| Colles' | Distal radius, DORSAL angulation, extra-articular (dinner fork; FOOSH extended) |
| Smith's | Distal radius, VOLAR angulation (garden spade; fall on flexed wrist) |
| Barton's | Fracture-dislocation of radiocarpal joint, intra-articular volar OR dorsal lip |
| Chauffeur's | Radial styloid fracture |
| Monteggia | Proximal 1/3 ULNA # + radial head dislocation |
| Galeazzi | Distal 1/3 RADIUS # + DRUJ dislocation ('fracture of necessity') |
| Nightstick | Isolated ulnar shaft # from direct blow |
| Boxer's | 5th metacarpal NECK fracture |
| Bennett's | Intra-articular # at base of 1st MC (thumb base, axial load) |
| Holstein-Lewis | Distal 1/3 humeral spiral # + high radial-nerve injury risk |
| Jones # (Zone 2, 5th MT) | Metaphyseal–diaphyseal junction, vascular watershed → non-union |
| Dancer's / Pseudo-Jones (Zone 1) | 5th MT tuberosity avulsion (peroneus brevis) |
| Lover's fracture | Calcaneus (axial loading, fall from height) |
| Crescent sign | AVN — earliest X-ray sign |
| Brodie's abscess (well-enclosed cavity) | Subacute haematogenous osteomyelitis |
| Sequestrum + involucrum | Osteomyelitis (dead bone + reactive new bone) |
| Sunburst periosteal reaction | Osteosarcoma |
| Hill-Sachs + Bankart | Anterior shoulder dislocation (reversed = posterior) |
| Scottie-dog collar (oblique X-ray) | Pars interarticularis defect = spondylolysis |
| Myelomalacia (white cord signal, MRI) | Cervical myelopathy |
| Finkelstein | De Quervain's tenosynovitis |
| Tinel's / Phalen's | Carpal tunnel syndrome (median nerve) |
| Hueston's tabletop (palm won't flatten) | Dupuytren's disease (DIPJ spared) |
| Kanavel's 4 signs | Pyogenic flexor tenosynovitis |
| Jobe's empty-can | Supraspinatus tear |
| Resisted external rotation | Infraspinatus tear |
| Gerber's lift-off | Subscapularis tear |
| Hawkins-Kennedy / painful arc | Subacromial impingement (Scarf = AC joint) |
| Posterior sag / posterior drawer | PCL tear |
| Anterior drawer (ankle) | ATFL injury |
| Ulnar paradox (partial claw hand) | Cubital tunnel syndrome (ulnar nerve at elbow) |
Criteria / classifications / scores at a glance
- Four R's (fracture mgmt order): Resuscitation → Reduction → Immobilisation → Rehabilitation
- ATLS primary survey (ABCDE): Airway + C-spine · Breathing · Circulation + haemorrhage control · Disability · Exposure/environment
- AMPLE history: Allergies · Medications · Past medical hx · Last meal · Events surrounding injury
- Apley's exam: Look · Feel · Move · Special tests (+ joint above AND joint below)
- RICE (acute soft-tissue / sprain): Rest · Ice · Compression · Elevation
- Edinburgh position (Boxer's / 5th MC neck #): wrist extended 20°, MCP flexed 60–70°, IPs in extension
- Gustilo (open #): I ≤1 cm, minimal contamination · II 1–10 cm, moderate soft-tissue injury · IIIA usually >10 cm, high energy/contaminated, ADEQUATE tissue for flap · IIIB extensive PERIOSTEAL stripping → needs plastic cover · IIIC associated vascular injury needing repair. Farm injuries automatically ≥IIIA.
- Mirels' score (MBD impending #): >8 → consider prophylactic stabilisation (four components not individually detailed in deck)
- Compartment-pressure thresholds: absolute >40 mmHg, OR delta (diastolic BP − compartment) <30 mmHg; diagnosis mainly clinical
- Kocher's NEWT (paediatric septic arthritis): Non-weight-bearing · Elevated ESR · White-cell count elevated · Temperature (fever)
- MSIS 2011 definite PJI: EITHER major (sinus tract to prosthesis, OR pathogen in ≥2 separate samples) OR 4 of 6 minor (↑ESR + CRP; ↑synovial leukocytes; ↑synovial PMN%; purulence; 1 positive periprosthetic culture; >5 neutrophils/HPF in 5 HPFs at ×400)
- DAIR (early PJI <3 wk): Debridement · Antibiotics · Implant Retention; absolute cut-off 3 weeks from symptom onset
- One- vs two-stage PJI revision: one-stage if organism KNOWN (new implant + antibiotic-loaded cement, 3 peri-op doses) · two-stage if UNKNOWN — stage 1: remove implant + debride + odd-number samples (3/5/7) + antibiotic-cement spacer + 6 wk antibiotics → stage 2: remove spacer + new implant, no antibiotics
- 5th MT base zones: Zone 1 Avulsion/Dancer's/Pseudo-Jones (tuberosity, peroneus brevis) · Zone 2 JONES # (metaphyseal–diaphyseal junction, watershed → non-union) · Zone 3 proximal diaphyseal stress # in athletes
- Cobb's angle (scoliosis): <30° non-op (posture/strengthening, Milwaukee brace) · >30° or expected to progress → operative correction + rebalancing
- Hyperkyphosis angle: >50° → operative correction + spinal fixation
- Synovial fluid: Normal = clear yellow, high viscosity, few WBC · Septic = purulent, LOW viscosity, WBC >10,000/mm³, LOW glucose, +ve bacteriology · Gout = cloudy, URATE crystals · Pseudogout = cloudy, PYROPHOSPHATE crystals
- Arthroplasty complications (5): PJI · dislocation · limb-length discrepancy · osteolysis · polyethylene wear
- Fracture description (imaging): shape by line — transverse / oblique / spiral / longitudinal; angulation medial = valgus, lateral = varus; overriding + foreshortening = bayonet apposition; children — bowing/plastic, torus/buckle, greenstick
- Bankart (shoulder instability): I cartilaginous (antero-inferior labrum/IGHL avulsion) · II bony (+ antero-inferior glenoid rim #); paired with Hill-Sachs (postero-lateral humeral head impaction) in anterior dislocation
- Modic end-plate (MRI): I oedema (low T1, bright T2) · II fatty (bright T1 & T2) · III sclerotic (low T1 & T2)
- Meyerding (spondylolisthesis): graded I–IV by % vertebral slippage
- Meniscal signal grades (MRI): 1 globular (asymptomatic) · 2 linear not reaching surface · 3 reaches one articular surface (= tear) · 4 complex, both surfaces
- Sacroiliitis MRI phases: oedema (STIR bright, active, most sensitive) → fatty (bright T1/T2) → sclerotic (low T1/T2, seen on plain X-ray)
Discriminators that decide questions
- Colles' vs Smith's — both distal radius, extra-articular: Colles' = DORSAL angulation (FOOSH, wrist extended, dinner fork); Smith's = VOLAR angulation (fall on flexed wrist, garden spade, always operative/ORIF).
- Monteggia vs Galeazzi — Monteggia = proximal 1/3 ULNA # + radial head dislocation (easily missed); Galeazzi = distal 1/3 RADIUS # + DRUJ dislocation, 3× as common, 'fracture of necessity' (always surgical).
- Non-union: hypertrophic vs atrophic — hypertrophic = good blood supply, flared ends + abundant callus (mechanical cause) → STABILISATION; atrophic = poor vascularity + too-rigid fixation, withered ends → BIOLOGICAL enhancement (bone graft).
- NOF #: intracapsular vs extracapsular — intracapsular (femoral head, subcapital, trans-cervical) = high AVN/non-union risk (medial femoral circumflex supply disrupted); extracapsular (basicervical, trochanteric) = blood supply preserved, low AVN.
- Osteosarcoma vs Ewing's — osteosarcoma = most common bone sarcoma, around KNEE (50%)/SHOULDER (25%), peak 2nd decade, metastasises early; Ewing's = 2nd most common, typically DIAPHYSEAL, 80% in first two decades.