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Orthopedic Imaging and Fractures

Jun 20, 2025

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Overview

This lecture covers key orthopedic images and their clinical relevance, focusing on fracture identification, important radiographic signs, fixation devices, complications, and common deformities and tests relevant for exams.

Common Splints and Their Uses

  • Thomas splint: Used for lower limb fractures, mainly femoral fractures.
  • Bohler-Braun splint: Used for femur and tibia fractures; can prevent equinus deformity in foot drop.

Pediatric Fractures

  • Greenstick fracture: Unicortical fracture seen in children, especially radius; fracture on convex side from bending force.
  • Torus (buckle) fracture: Bulging of cortex in children, also typically in forearm.

Femur Fractures and Healing

  • Shaft femur fractures can be fixed with intramedullary rods (secondary healing with callus) or compression plates (primary healing without callus).
  • Intramedullary nailing gives secondary (endochondral) healing; compression plating leads to primary (intramembranous) healing.

Open Fractures and Fixators

  • Gustilo-Anderson classification: Type I (<1cm), Type II (1-10cm), Type III (>10cm, with subtypes A: contamination, B: periosteal stripping, C: vascular injury).
  • External fixators: Uniplanar, ring (Ilizarov), rail (LRS), and spanning (across joints).

Foot and Ankle Fractures

  • March fracture: Stress fracture at the neck of the second metatarsal.
  • Jones fracture: Base of the fifth metatarsal, poor healing, needs 6–8 weeks immobilization.
  • Bimalleolar (Pott’s) and trimalleolar (Cotton) fractures: Involvement of malleoli.

Shoulder and Upper Limb Injuries

  • Clavicle fracture: Common at junction of medial 2/3 and lateral 1/3.
  • Anterior shoulder dislocation: Flattened shoulder contour; head not in glenoid.
  • Posterior dislocation: Light bulb sign on X-ray.
  • Holstein-Lewis fracture: Humeral shaft (upper 2/3-lower 1/3), risk of radial nerve injury.
  • Supracondylar humerus fracture: Above condyles, Gartland classification; most common complication is malunion (cubitus varus).

Elbow and Wrist Injuries

  • Lateral condyle fracture (Salter-Harris type IV): Leads to cubitus valgus.
  • Supracondylar fracture (type I/II): Three-point bony relationship undisturbed.
  • Monteggia fracture: Ulna fracture with radial head dislocation.
  • Galeazzi fracture: Radius fracture with distal radioulnar joint disruption.

Distal Radius and Carpal Injuries

  • Colles’ fracture: Distal radius, dorsal displacement (dinner fork deformity).
  • Smith’s fracture: Volar displacement (garden spade deformity).
  • Chauffeur's fracture: Radial styloid fracture.
  • Scaphoid fracture: Tenderness in anatomical snuffbox; poor blood supply.
  • Scapholunate dissociation: Increased gap >3-4mm (Terry Thomas sign).

Hand Injuries

  • Boxer's fracture: Fifth metacarpal neck.
  • Mallet finger: Flexed DIP from extensor tendon injury.
  • Trigger finger: Due to A1 pulley at MCP joint (most often ring finger).

Hip and Lower Limb Injuries

  • Posterior hip dislocation: Flexion, adduction, internal rotation, limb shortening.
  • Anterior dislocation: Flexion, abduction, external rotation, limb lengthening.
  • Intracapsular (neck) vs. extracapsular (intertrochanteric) femur fractures.
  • Trendelenburg test: Healthy side sinks; indicates abductor or superior gluteal nerve palsy.
  • Thomas test: For hip flexion contracture.
  • Gallows traction: For femur fractures in children <2 years.

Knee and Patella Injuries

  • Patella fracture: Most often transverse; treated with tension band wiring with K-wires.
  • Bipartite patella: Congenital, accessory ossification center.

Bone Lesions and Tumors

  • Simple bone cyst: Fallen leaf sign.
  • Osteochondroma: Bone outgrowth away from joint (exostosis).
  • Enchondroma: Lytic lesion with calcification in small hand/foot bones.
  • Giant cell tumor: Epiphyseal, soap-bubble appearance under articular surface.
  • Osteosarcoma: Codman's triangle and sunburst appearance.
  • Ewing's sarcoma: Onion peel periosteal reaction.

Nerve Palsies and Hand Deformities

  • Ulnar nerve palsy: Claw hand, positive card test, use knuckle-bender splint.
  • Median nerve palsy: Ape hand, pointing index (benediction sign), weak OK sign.
  • Radial nerve palsy: Wrist drop, treated with cock-up splint.
  • Erb's palsy: Waiter's/policeman's tip deformity.
  • Foot drop: Common peroneal nerve injury (high stepping gait, AFO splint).

Orthopedic Tests and Instruments

  • Phalen's and Durkan's tests: For carpal tunnel syndrome (median nerve).
  • Roos test: For thoracic outlet syndrome.
  • Anterior drawer test: ACL; Lachman’s test for acute ACL.
  • Posterior drawer test: PCL.
  • Instruments: Bone plate holding forceps (one smooth, one serrated), bone cutter, Ferguson’s forceps, chisel, osteotome.

Pediatric Deformities and Metabolic Bone Disease

  • Rickets: Cupping, fraying, and widening at metaphyses; white line of Frankel indicates healing.
  • Genu valgum/varum: Knock-knees (idiopathic > rickets), bowlegs (rickets > idiopathic), windswept (rickets).
  • Scurvy: White line of Frankel, Wimberger ring sign (epiphyseal sclerosis).

Spine Disorders

  • Codfish vertebra: End-plate biconcavity (osteoporosis).
  • Compression (wedge) fracture: Flexion injury.
  • Picture frame vertebra: Paget disease.
  • Ivory vertebra: Paget, lymphoma, metastasis.
  • Bamboo spine: Ankylosing spondylitis; dagger/trolley track sign on X-ray.
  • Vertebral burst/chance fractures: Axial/flexion injuries; best seen on CT.

Other Conditions and Signs

  • Myositis ossificans: Bony mass post-elbow fracture/massage.
  • Shepherd crook deformity: Proximal femur in fibrous dysplasia.
  • Chronic osteomyelitis: Sequestrum (dead bone), involucrum (new bone), cloaca (opening).
  • Clubfoot: Treated with Dennis-Brown splint.
  • Sprengel shoulder: Elevated scapula.

Key Terms & Definitions

  • Greenstick fracture — Unicortical fracture in children from bending force.
  • Gustilo-Anderson classification — System for grading open fractures.
  • Trendelenburg test — Assesses hip abductor function; healthy side drops.
  • Codman's triangle — Periosteal new bone formation in aggressive bone lesions.
  • Onion peel appearance — Laminated periosteal reaction, often Ewing's sarcoma.
  • Dinner fork deformity — Colles' fracture appearance.
  • Bamboo spine — Fusion of spine seen in ankylosing spondylitis.
  • Mallet finger — DIP flexion due to extensor tendon rupture.

Action Items / Next Steps

  • Review images and signs described for each fracture and deformity.
  • Practice identifying normal vs. abnormal X-rays for common sites.
  • Memorize common splint names and indications.
  • Study Gustilo-Anderson, Gartland, and Salter-Harris classifications.
  • Revise key orthopedic tests and their clinical significance for exams.

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