200+ Free ONC Practice Questions

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Question 1

Score: 0/0

Which pathophysiological change is most characteristic of osteoarthritis?

Synovial membrane inflammation and pannus formation

Progressive loss of articular cartilage with subchondral bone changes

Autoimmune destruction of joint tissues

Septic invasion of joint space with purulent exudate

to track

2026 Statistics

Key Facts: ONC Exam

150

Questions (135 scored)

ONCB test plan

3 hours

Exam Time

ONCB

97/135

Passing Score (~72%)

ONCB

~80%

First-Time Pass Rate

ONCB data

$425

Exam Fee (non-member)

ONCB 2026

7,800+

Certified ONC Nurses

ONCB

38%

Degenerative Disorders

Largest domain

5 years

Certification Valid

ONCB policy

The ONC exam has an approximately 80% first-time pass rate. The exam includes 150 questions (135 scored, 15 pilot) with 3 hours to complete. NAON members receive significant exam fee discounts. With 7,800+ certified orthopaedic nurses, the ONC credential demonstrates specialized expertise in musculoskeletal care. ONC-certified nurses work in hospitals, ambulatory surgery centers, specialty clinics, and sports medicine facilities with average salaries exceeding $85,000 annually.

Sample ONC Practice Questions

Try these sample questions to test your ONC exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 200+ question experience with AI tutoring.

1Which pathophysiological change is most characteristic of osteoarthritis?

A.Synovial membrane inflammation and pannus formation

B.Progressive loss of articular cartilage with subchondral bone changes

C.Autoimmune destruction of joint tissues

D.Septic invasion of joint space with purulent exudate

Explanation: Osteoarthritis is characterized by progressive loss of articular cartilage, subchondral bone sclerosis, cyst formation, and osteophyte development. Unlike rheumatoid arthritis, it is not primarily an inflammatory or autoimmune condition.

2A patient with knee osteoarthritis reports increased pain with activity that improves with rest. Which nursing intervention is most appropriate?

A.Recommend complete bed rest to prevent further joint damage

B.Encourage activity pacing and weight management

C.Prescribe high-impact aerobic exercise

D.Suggest immobilization with a knee brace continuously

Explanation: Activity pacing and weight management are key nursing interventions for osteoarthritis. Complete rest can lead to muscle atrophy and stiffness. High-impact exercise may worsen symptoms. Immobilization should be limited.

3Which risk factor is most strongly associated with the development of primary osteoarthritis?

A.Previous joint infection

B.Advanced age

C.Rheumatoid arthritis

D.Hemophilia

Explanation: Advanced age is the strongest risk factor for primary osteoarthritis. Previous joint infection, rheumatoid arthritis, and hemophilia are associated with secondary osteoarthritis. Primary osteoarthritis is idiopathic and age-related.

4What is the primary nursing priority during the first 24 hours after total knee arthroplasty?

A.Initiate aggressive physical therapy

B.Monitor for neurovascular compromise and bleeding

C.Discontinue all pain medications

D.Remove surgical drains immediately

Explanation: In the first 24 hours post-TKA, monitoring for neurovascular compromise (assessing circulation, sensation, movement) and bleeding are critical priorities. Aggressive PT is introduced gradually. Drains are managed per protocol.

5Which clinical manifestation distinguishes rheumatoid arthritis from osteoarthritis?

A.Joint pain that worsens with activity

B.Morning stiffness lasting greater than 1 hour

C.Heberden's nodes on distal interphalangeal joints

D.Asymmetric joint involvement

Explanation: Morning stiffness lasting greater than 1 hour is characteristic of rheumatoid arthritis. OA typically has stiffness lasting less than 30 minutes. Heberden's nodes and asymmetric involvement are features of OA.

6A patient 8 hours post-op total hip arthroplasty reports sudden severe hip pain and external rotation of the leg. What is the most likely complication?

A.Deep vein thrombosis

B.Dislocation of the prosthesis

C.Periprosthetic fracture

D.Sciatic nerve injury

Explanation: Sudden severe pain with external rotation of the leg in a post-op THA patient strongly suggests prosthetic dislocation. This is a surgical emergency requiring immediate physician notification.

7Which position should be avoided in a patient with a posterior approach total hip arthroplasty?

A.Supine with pillow between legs

B.Hip flexion greater than 90 degrees with adduction

C.Side-lying with operative side up

D.Standing with walker assistance

Explanation: For posterior approach THA, hip flexion greater than 90 degrees combined with adduction and internal rotation risks dislocation. These positions violate the posterior hip precautions and must be avoided.

8What is the most common complication following total joint arthroplasty?

A.Prosthetic joint infection

B.Deep vein thrombosis

C.Dislocation

D.Periprosthetic fracture

Explanation: Deep vein thrombosis (DVT) is the most common complication following total joint arthroplasty. While prosthetic joint infection is serious, it occurs less frequently. DVT prophylaxis is essential post-operatively.

9Which assessment finding is most concerning for compartment syndrome in a patient with a tibial fracture?

A.Pain unrelieved by opioid analgesics

B.Edema at the fracture site

C.Warmth over the affected area

D.Inability to bear weight

Explanation: Pain disproportionate to injury and unrelieved by opioids is the earliest and most reliable sign of compartment syndrome. The "5 Ps" (pain, pallor, pulselessness, paresthesia, paralysis) guide assessment, with pain being most significant.

10A patient with rheumatoid arthritis is scheduled for total knee arthroplasty. Which preoperative consideration is most important?

A.Discontinue all immunosuppressive medications immediately

B.Assess cervical spine stability before intubation

C.Avoid antibiotic prophylaxis due to allergy risk

D.Schedule surgery during acute disease flare

Explanation: RA patients often have cervical spine instability (atlantoaxial subluxation). Preoperative cervical spine assessment is crucial before intubation. Immunosuppressants are managed, not stopped abruptly. Surgery should be during remission.

About the ONC Exam

The ONC certification validates expertise in orthopaedic nursing care across 8 musculoskeletal condition domains and nursing tasks. The exam covers degenerative disorders (38%), orthopaedic trauma (19%), sports injuries (11%), metabolic bone disorders (9%), inflammatory disorders (8%), congenital/pediatric conditions (5%), musculoskeletal tumors (5%), and neuromuscular conditions (4%). Nursing tasks include pain management, complications prevention, self-care education, activity/mobility support, nutrition, and psychosocial care.

Questions

150 scored questions

Time Limit

3 hours

Passing Score

97/135 (72%)

Exam Fee

$425 (non-members), $300-340 (members) (ONCB (Orthopaedic Nurses Certification Board))

ONC Exam Content Outline

38%

Degenerative Disorders

Osteoarthritis, rheumatoid arthritis, avascular necrosis, spinal stenosis, degenerative disc disease, total joint replacement (hip, knee, shoulder), revision arthroplasty, joint replacement complications

19%

Orthopaedic Trauma

Fracture classification and healing, open/closed fractures, fracture complications, compartment syndrome, fat embolism syndrome, hip fractures, pelvic fractures, spinal cord injury, casting, traction, external fixation

11%

Sports Injuries

Meniscal injuries, ligament injuries (ACL, PCL, MCL, LCL), shoulder instability, rotator cuff injuries, tendon injuries, cartilage injuries, concussion, return-to-play criteria, injury prevention

Metabolic Bone Disorders

Osteoporosis, osteopenia, osteomalacia, Paget's disease, vertebral compression fractures, bone mineral density, bisphosphonates, calcium and vitamin D metabolism

Inflammatory Disorders

Septic arthritis, osteomyelitis, seronegative spondyloarthropathies (ankylosing spondylitis, psoriatic arthritis), gout, pseudogout, infectious disorders

Congenital/Pediatric

Developmental dysplasia of the hip, clubfoot, adolescent idiopathic scoliosis, spinal deformities, cerebral palsy orthopaedic manifestations, pediatric fractures, physeal injuries

Musculoskeletal Tumors

Benign bone tumors (osteochondroma, osteoid osteoma), malignant bone tumors (osteosarcoma, Ewing sarcoma, chondrosarcoma), metastatic bone disease, soft tissue sarcomas

Neuromuscular

Low back pain, herniated disc, sciatica, cervical radiculopathy, muscular dystrophies, carpal tunnel syndrome, peripheral nerve injuries, complex regional pain syndrome

How to Pass the ONC Exam

What You Need to Know

Passing score: 97/135 (72%)
Exam length: 150 questions
Time limit: 3 hours
Exam fee: $425 (non-members), $300-340 (members)

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

ONC Study Tips from Top Performers

1Focus on total joint arthroplasty nursing care - this is the highest-weighted content area

2Master hip precautions for posterior approach THA: no flexion >90°, no adduction, no internal rotation

3Know the 5 Ps of compartment syndrome: Pain, Pallor, Pulselessness, Paresthesia, Paralysis (pain is earliest sign)

4Understand VTE prophylaxis: mechanical (SCDs) + chemical (anticoagulants) + early mobilization

5Study fracture healing phases: inflammatory, reparative (soft callus → hard callus), remodeling

6Learn the Gustilo-Anderson classification for open fractures (Grade I, II, IIIA, IIIB, IIIC)

7Know fat embolism syndrome classic triad: respiratory distress, neurological changes, petechial rash

8Master osteoporosis medications: bisphosphonates (alendronate), denosumab, teriparatide - know administration and side effects

9Study common orthopaedic emergencies: compartment syndrome, fat embolism, neurovascular compromise, cauda equina

10Understand pediatric orthopaedic conditions: DDH (Pavlik harness), clubfoot (Ponseti method), scoliosis (Adams test)

11Learn assistive device progression: walker → crutches → cane → independent (safest to least restrictive)

12Know wound care for joint replacement: assess for infection signs, delayed healing, wound drainage

Frequently Asked Questions

What is the ONC certification?

The ONC (Orthopaedic Nurse Certified) is a specialty certification offered by the Orthopaedic Nurses Certification Board (ONCB) for registered nurses specializing in orthopaedic nursing. It validates expertise in musculoskeletal conditions, orthopaedic surgery care, trauma management, and rehabilitation. The certification is accredited by the Accreditation Board for Specialty Nursing Certification (ABSNC).

What are the eligibility requirements for the ONC exam?

To be eligible for the ONC exam, you must: 1) Hold a current, unrestricted RN license in the US or Canada, 2) Have at least 2 years (24 months) of experience as an RN, 3) Have a minimum of 1,000 hours of orthopaedic nursing practice within the past 3 years. Orthopaedic practice includes direct patient care, education, research, or administration in orthopaedic nursing.

How many questions are on the ONC exam?

The ONC exam consists of 150 multiple-choice questions. Of these, 135 are scored questions and 15 are pilot (unscored) questions used for future exam development. You have 3 hours to complete the exam. The exam is administered via computer at Prometric testing centers.

What is the passing score for the ONC exam?

The passing score for the ONC exam is 97 correct answers out of 135 scored questions (approximately 72%). You will receive preliminary pass/fail results immediately after completing the exam, with official results mailed within 2-3 weeks.

How much does the ONC exam cost?

The ONC exam fee is $425 for non-members. NAON (National Association of Orthopaedic Nurses) members receive discounted rates: $300 for professional members and $340 for affiliate members. Membership pays for itself with the exam discount plus additional member benefits including journal subscriptions and educational resources.

What topics are covered on the ONC exam?

The ONC exam covers 8 musculoskeletal condition domains: Degenerative Disorders (38%), Orthopaedic Trauma (19%), Sports Injuries (11%), Metabolic Bone Disorders (9%), Inflammatory Disorders (8%), Congenital/Pediatric (5%), Musculoskeletal Tumors (5%), and Neuromuscular (4%). Cross-cutting nursing tasks include pain management, complications prevention, self-care education, activity/mobility support, nutrition, and psychosocial care.

How should I prepare for the ONC exam?

Effective preparation includes: 1) Reviewing the ONCB Test Content Outline and Test References, 2) Studying core orthopaedic nursing texts (Core Curriculum for Orthopaedic Nursing), 3) Completing at least 1,500-2,000 practice questions, 4) Focusing on high-yield topics: joint replacement care, fracture management, complications (compartment syndrome, DVT, fat embolism), and orthopaedic emergencies. Use our AI tutor to master difficult concepts and rationales.

How long is the ONC certification valid?

The ONC certification is valid for 5 years. Recertification can be achieved by either: 1) Retaking and passing the ONC exam, OR 2) Completing 75 contact hours of orthopaedic nursing continuing education plus 1,000 practice hours in orthopaedic nursing during the 5-year period. The ONCB also accepts academic credit, presentations, publications, and preceptorship for contact hours.

What is the average salary for an ONC-certified nurse?

ONC-certified nurses typically earn 5-10% more than non-certified orthopaedic nurses. According to industry data, orthopaedic nurses with ONC certification average $85,000-$95,000 annually, with variations based on location, experience, and practice setting. Many institutions offer certification bonuses and higher pay scales for certified nurses.