ONC Study Guide: High-Yield Topics on Fracture Management and Post-Op Care for Orthopaedic Nurses

Fracture patients test a nurse’s full skill set: keen assessment, calm teaching, and sharp clinical judgment. For the ONC exam and for real-world practice, you need to know what to do first, what can’t wait, and how to prevent the most serious complications. This study guide focuses on high-yield fracture management and post-op care topics, with the “why” behind each step so you can reason through tricky situations.

Fracture basics you must recognize quickly

Why it matters: The type of fracture and its stability drive your priorities: how fast to act, what to monitor, and how to protect tissue perfusion.

• Open vs. closed: Open fractures break skin. These carry a high infection risk because bacteria can reach bone. They need urgent IV antibiotics and sterile coverage.
• Displaced vs. nondisplaced: Displacement disrupts alignment and blood supply. More pain, swelling, and soft-tissue injury are common.
• Stable vs. unstable: Unstable fractures move even after reduction and can re-injure vessels and nerves. More frequent neurovascular checks are needed.
• Pattern clues: Spiral fractures suggest torsion; comminuted means multiple fragments and soft-tissue damage; impacted fractures occur when fragments drive into each other, often masking initial swelling.
• Special populations: Children have growth plates (physis). Injuries here risk growth disturbance. Older adults have fragile bone and often present after a simple fall with hip or wrist fractures.

Initial assessment: what to do first

Why it matters: Early actions prevent irreversible damage. Missed neurovascular compromise and uncontrolled swelling cause disability.

• Stabilize ABCs first. Hypoxia and bleeding kill faster than a fracture. Control bleeding with direct pressure. Avoid circumferential tight dressings that can worsen swelling.
• Immobilize the limb above and below the injury. It reduces pain and limits further soft-tissue and vascular damage.
• Neurovascular checks (baseline and frequent): Document color, temperature, cap refill, pulses, motor, and sensation. Compare sides. Changes often occur fast with swelling.
• Pain control early and reassess. Unrelieved pain may signal compartment syndrome, not just undertreated pain. Reassess after each intervention.
• Open fracture care: Cover with sterile, moist dressing. Start IV antibiotics as soon as possible (ideally within 1 hour). Update tetanus. Do not probe the wound; that pushes bacteria deeper.
• Keep NPO if surgery likely. Reduces aspiration risk if urgent anesthesia is needed.

High-yield: recognizing and acting on compartment syndrome

Why it matters: Compartment syndrome is a limb-threatening emergency. Fasciotomy is time-sensitive. Delays cause necrosis, contractures, and amputation.

• Classic signs: Pain out of proportion and pain with passive stretch are early. Paresthesia, pallor, paralysis, and pulselessness are late. Pulses can be present, so do not rely on them alone.
• What to do now: Call the surgeon immediately. Loosen or remove constrictive dressings. Keep the limb at heart level (not elevated high). Avoid ice, which reduces arterial inflow. Prepare for possible fasciotomy.
• Documentation: Note time, exact findings, and your actions. Frequent reassessment shows trend and supports urgent decisions.

Cast and splint care

Why it matters: Casts can hide swelling and pressure injuries. Early teaching prevents skin breakdown, burns, and missed ischemia.

• First 24–48 hours: Elevate the limb above the heart to reduce edema and pain. Ice packs can be used around, not directly on wet plaster, to avoid softening and thermal injury.
• Move exposed joints and wiggle toes/fingers. Motion reduces stiffness and venous stasis. It also helps the patient notice new numbness or weakness early.
• Keep the cast dry and cool. Moisture weakens plaster and macerates skin. Heat increases swelling and itching.
• No objects inside the cast. Scratching causes skin lacerations and infection. Teach the “cool setting only” hair-dryer trick for itching.
• Red flags (“hot spots”): Burning pain at one site, bad odor, fever, or a soft area suggests infection or pressure necrosis. Contact the team immediately.
• Body cast risk – cast syndrome (SMA syndrome): Nausea, early satiety, abdominal pain from duodenal compression. Loosen or bivalve cast and elevate the head of bed. This prevents ischemia and aspiration.

Traction essentials

Why it matters: Traction aligns the limb, reduces spasms, and protects tissue until surgery. Small setup errors cause pain and neurovascular harm.

• Skin traction (e.g., Buck’s): Temporary. Lower weight limits. Monitor skin closely for blisters and breakdown.
• Skeletal traction: Pins through bone allow stronger, longer traction. Inspect pin sites and neurovascular status at least every shift and with any change in pain.
• Rules: Weights hang freely. No resting on the floor or bed. Lines stay straight, with no knots at pulleys. Reposition the patient with a trapeze; do not lift weights.
• Why strict alignment: Off-axis pull increases pain and can worsen the fracture. Free weights maintain constant force, reducing muscle spasm and bleeding.

External fixators and pin-site care

Why it matters: Pin infections can become osteomyelitis. Clean technique and consistent assessment prevent deep infection.

• Daily inspection: Look for erythema, heat, drainage, or loosening. Pain that localizes to a pin is concerning.
• Cleaning: Follow facility protocol (chlorhexidine or sterile saline). One swab per pin. Work from the pin outward to avoid dragging bacteria into the site.
• Stability first: Never adjust clamps without an order. Movement at the pin-bone interface drives infection and nonunion.

Post-op priorities after ORIF or arthroplasty for fracture

Why it matters: The first 24–72 hours decide the path: stable healing vs. complications. Clear routines limit risk.

• Airway, breathing, circulation, then surgical site. Check drains, dressings, and the limb’s neurovascular status on arrival and at frequent intervals.
• Weight-bearing status: Know the order and teach it exactly:
  • NWB: No weight on the limb.
  • TTWB/TDWB: Toes down for balance only; about 10–15% body weight.
  • PWB: Usually 25–50% body weight as ordered.
  • WBAT: As tolerated by pain and safety.
• Antibiotics: Prophylaxis typically within 1 hour before incision and stopped within about 24 hours post-op unless there is a specific reason to continue. This reduces infection without promoting resistance.
• Glycemic control: Keep blood glucose under roughly 180 mg/dL. Hyperglycemia impairs leukocyte function and wound healing even in non-diabetics.
• Normothermia and oxygenation: Warm the patient and maintain oxygen to support tissue perfusion and collagen synthesis.
• Drains and dressings: Mark drainage outlines with time and date. Sudden increases, bright red bleeding, or loss of suction (for wound VAC) requires prompt evaluation.

Preventing VTE: never skip the basics

Why it matters: Orthopaedic trauma sharply raises DVT/PE risk. Prevention is more effective than late treatment.

• Chemoprophylaxis: LMWH, DOACs, or aspirin per protocol and risk profile. Teach patients that missed doses increase clot risk.
• Mechanical: SCDs and early ankle pumps improve venous return. Ensure sleeves fit correctly and stay on when in bed.
• Early mobilization: The best preventive tool. Even dangling or bedside standing helps.
• Warning signs: New calf pain/swelling, unilateral warmth, chest pain, dyspnea, tachycardia, hemoptysis. Escalate care immediately.

Pain management: multimodal and smart

Why it matters: Good pain control reduces delirium, improves sleep, and speeds rehab. Over-sedation and constipation create setbacks.

• Foundation: Scheduled acetaminophen reduces opioid needs. Check total daily dose limits to protect the liver.
• NSAIDs: Short courses may modestly delay bone healing in high-risk fractures. Use the lowest effective dose for the shortest time, and avoid in renal disease or GI bleed risk. Balance pain relief with healing needs.
• Opioids: Use the smallest dose that allows mobility and sleep. Combine with bowel prophylaxis (stool softener + stimulant). Reassess sedation and respiratory rate frequently, especially in older adults or with gabapentinoids.
• Adjuncts: Muscle relaxants for spasms; gabapentin or duloxetine for neuropathic features. Regional blocks can offer strong relief with fewer systemic effects.
• Non-drug: Elevation, ice (if appropriate), splinting, repositioning, and guided breathing reduce pain by lowering swelling and muscle tension.

Geriatric fracture care and delirium prevention

Why it matters: Hip fractures in older adults carry high morbidity. Small nursing actions prevent big complications.

• Delirium prevention: Reorient often, keep glasses and hearing aids on, manage pain, avoid unnecessary catheters, and encourage daytime light and nighttime quiet. Delirium worsens falls and delays rehab.
• Early surgery and mobilization: Fewer complications and shorter stays. Get them to a chair or stand as ordered, usually within 24 hours post-op.
• Osteoporosis management: Calcium, vitamin D, and antiresorptive therapy after a fragility fracture prevent the next fracture. Teach fall prevention and home safety.
• Nutrition and hydration: Protein intake supports callus formation. Dehydration worsens hypotension and delirium.

Preventing infection: open fractures and post-op wounds

Why it matters: Infection can destroy hardware fixation and bone. Early antibiotics save limbs.

• Open fractures: Start broad-spectrum IV antibiotics quickly:
  • Type I–II (lower-energy): First-generation cephalosporin.
  • Type III (high-energy): Add gram-negative coverage (e.g., aminoglycoside) per protocol.
  • Farm or soil contamination: Add anaerobic coverage (e.g., penicillin) for clostridial risk.
• Debridement: Done as soon as feasible. Antibiotic timing is most critical; it reduces deep infection even before surgery.
• Post-op wound care: Keep dressings clean and dry. Do not remove the first dressing unless ordered; sterility matters. Teach patients how normal drainage evolves from sanguineous to serosanguineous to minimal.

Neurovascular checks: what to test and why

Why it matters: Missed nerve or vessel injury causes permanent deficits. Your exam guides urgent decisions.

• Perfusion: Skin color, temperature, cap refill, and pulses (palpated or Doppler). A cool, pale foot with slow refill suggests arterial compromise.
• Sensation and motor (examples):
  • Upper extremity: Thumb abduction (radial), “OK sign” pinch (anterior interosseous), finger ab/adduction (ulnar).
  • Lower extremity: Great toe extension (deep peroneal), foot eversion (superficial peroneal), plantarflexion and sole sensation (tibial).
• Compare sides and trend. Worsening numbness or new weakness is urgent—may signal compartment syndrome or hardware malposition.

Bone healing 101 and why some fractures don’t heal

Why it matters: Understanding healing stages helps you explain timelines, set expectations, and spot nonunion early.

• Stages:
  • Inflammation (days): Hematoma and cytokines recruit cells.
  • Reparative (weeks): Soft callus becomes hard callus as cartilage mineralizes.
  • Remodeling (months–years): Woven bone becomes lamellar, regaining strength along stress lines.
• Healing helpers: Good reduction, stable fixation or immobilization, intact blood supply, no infection, adequate protein and vitamin D, no nicotine. Weight-bearing as ordered stimulates bone through Wolff’s law.
• Delayed union/nonunion risks: Smoking, diabetes, NSAID overuse, steroids, large soft-tissue injury, infection, poor alignment, and inadequate stabilization.
• Clinical clues: Ongoing pain at the fracture site after expected healing window, motion at the site, and failure to progress on X-ray.

Rehab and mobility: get moving, but protect the repair

Why it matters: Safe mobility prevents DVT, pneumonia, and deconditioning, and promotes bone strength.

• Teach and coach weight-bearing: Use bathroom scale or therapist guidance to feel 25–50% PWB. Clear, repeated coaching prevents overloading hardware.
• Assistive devices: Fit crutches or walkers so elbows flex about 20–30 degrees. Teach a step-to or step-through pattern based on pain and stability.
• Hip surgery precautions: After posterior-approach arthroplasty (common for some hip fracture treatments), avoid hip flexion past 90 degrees, adduction past midline, and internal rotation. These reduce dislocation risk while soft tissues heal.
• Pressure injury prevention: Reposition every two hours, float heels, and inspect bony prominences. Nutrition and moisture control matter as much as turning.

Region-specific pearls you’ll see on the ONC exam

• Hip fractures (elderly): Watch for external rotation and leg shortening. Pain with gentle log roll is typical. Early surgery and mobilization reduce mortality.
• Femoral shaft: High blood loss risk from thigh compartments. Monitor hemoglobin and perfusion closely.
• Tibia (shaft or plateau): High compartment syndrome risk. Mark swelling borders and reassess pain with passive stretch of toes/ankle.
• Ankle fractures: Elevate aggressively to control swelling before and after surgery. Check peroneal nerve (dorsiflexion, eversion).
• Distal radius (“Colles’”): Median nerve compression causes thumb-index finger numbness or weakness. Teach finger ROM to avoid stiffness.
• Pelvic fractures: Suspect associated bleeding. Monitor vitals, hemoglobin, and urinary output closely. Bed rest protocols vary; follow weight-bearing orders exactly.
• Humerus (proximal): Assess axillary nerve (sensation over lateral shoulder, deltoid activation). Sling positioning prevents swelling and nerve traction.

Documentation that protects patients (and you)

Why it matters: Clear documentation shows you saw the changes and acted promptly, which supports good outcomes and safe handoffs.

• Time-stamped neurovascular checks: Baseline on arrival, after interventions (reduction, casting), and per protocol (often hourly early on).
• Pain assessments and responses: Include functional impact (sleep, mobility). Note if pain is disproportionate or changes character.
• Traction and device details: Weights, alignment, pin care, and patient position.
• Education provided: What you taught, patient’s teach-back, and materials given. This improves safety at home.

Discharge teaching: what patients absolutely must know

Why it matters: Most complications show up at home. Patients who know what to watch for seek help sooner.

• Activity and weight-bearing: Repeat the exact order. Demonstrate how to use crutches or a walker on stairs. Practice transfers to bed, chair, and toilet.
• Cast/splint care: Keep dry, do not insert objects, elevate for swelling, and call if hot spots, odor, or cracks develop.
• Incision care: When to shower, how to change dressings if ordered, and what normal vs. abnormal drainage looks like.
• Medications: Pain plan (scheduled vs. as needed), bowel regimen, anticoagulants (timing and bleeding signs), and when to stop antibiotics if prescribed.
• Nutrition: Adequate protein, hydration, calcium, and vitamin D. Avoid nicotine. Explain that these choices speed healing.
• Urgent red flags:
  • Sudden severe pain or pain with passive stretch that is new.
  • Numbness, tingling, weakness, pale or cold toes/fingers.
  • Fever, foul drainage, or spreading redness.
  • Calf pain/swelling, chest pain, shortness of breath.
  • Uncontrolled nausea/vomiting, inability to pass urine, or severe constipation.
• Follow-up: Confirm dates, imaging needs, and how to reach the care team after hours.

Exam-ready quick hitters

• Earliest compartment sign: Pain with passive stretch (not pulselessness).
• Traction rule: Weights hang freely; do not lift or rest them.
• Open fracture priority: Start IV antibiotics fast; cover with sterile dressing; tetanus.
• Cast warning: Hot spot or bad odor means possible pressure or infection—escalate.
• VTE prevention: Chemoprophylaxis + SCDs + early mobilization beat any single method.
• Delirium prevention: Vision/hearing aids, pain control, sleep hygiene, avoid unnecessary catheters and restraints.
• Pin care: One swab per pin, clean outwards, assess for loosening and drainage.
• Weight-bearing terms: TTWB = balance only; PWB = 25–50% as ordered; WBAT = guided by pain and safety.

Bottom line: High-yield fracture care is pattern recognition plus disciplined routines. Do frequent neurovascular checks, control swelling, align and protect the limb, prevent clots and infection, and teach clearly. When in doubt, reassess, compare sides, and escalate early. That’s how you pass the ONC exam—and keep your patients safe.

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com