Free ONP-C Practice Questions

Question 1

A 68-year-old woman with advanced radiographic knee osteoarthritis has night pain and cannot walk one block despite six months of exercise therapy, weight-management support, and appropriate analgesia. After discussing alternatives, she chooses total knee arthroplasty. Her BMI is 38 kg/m²; she does not smoke, has no diabetes, and has no other condition requiring optimization. Which scheduling recommendation is consistent with the 2023 ACR/AAHKS guideline?

Accepted Answer

Proceed with surgical planning after counseling about her increased weight-related operative risks.

Answer

Require another three months of supervised physical therapy before reassessing surgical eligibility.

Answer

Arrange a trial of viscosupplementation before accepting that nonoperative treatment has failed.

Answer

Defer scheduling until her BMI falls below 35 kg/m² to reduce operative risk.

Question 2

Six hours after a tibial shaft fracture, a 34-year-old has escalating pain, pain with passive toe flexion, and new paresthesia despite release of all constrictive dressings. The foot is warm with palpable pulses. Blood pressure is 118/64 mm Hg, and repeated anterior-compartment pressures are 44 mm Hg. Which interpretation should direct care now?

Accepted Answer

The pressure difference is 20 mm Hg; obtain emergency surgical assessment for decompression.

Answer

The pressure difference is 44 mm Hg; repeat measurements after another dose of analgesia.

Answer

The pressure difference is 74 mm Hg; continue observation with serial neurovascular examinations.

Answer

The pressure difference is 20 mm Hg; obtain CT angiography before considering decompression.

Question 3

A recreational soccer player is examined four days after a blow to the lateral knee. Tenderness follows the medial collateral ligament. Valgus stress at 30 degrees produces mild opening with a firm endpoint, but the knee is stable in full extension. Lachman and posterior drawer testing are normal, and radiographs show no fracture. The patient can bear weight. Select the appropriate initial treatment.

Accepted Answer

A hinged knee brace with protected motion and progressive rehabilitation.

Answer

Long-leg cast immobilization for six weeks before beginning knee motion.

Answer

Early ligament reconstruction to prevent chronic instability during cutting activities.

Answer

MRI and an operative consultation before allowing rehabilitation to begin.

Question 4

A 67-year-old postmenopausal woman has no prior fragility fracture. Her femoral-neck T-score is -1.9, and her U.S. FRAX results are 4.2% for hip fracture and 16% for major osteoporotic fracture over 10 years. She asks why medication is being discussed when her scan does not show densitometric osteoporosis. Under the Bone Health and Osteoporosis Foundation treatment framework, the reason is that:

Accepted Answer

Her hip-fracture probability independently exceeds the threshold for treatment consideration.

Answer

Her combined fracture probability exceeds 20% when the two FRAX results are added.

Answer

Her femoral-neck T-score should be reclassified as osteoporosis because of her age.

Answer

Low bone mass in a woman older than 65 is sufficient by itself to justify medication.

Question 5

The referral says “rotator cuff tear,” but a 54-year-old woman with diabetes describes gradual shoulder stiffness without trauma. Active elevation reaches 85 degrees and passive elevation 90 degrees. Passive external rotation with the arm at the side is 10 degrees, compared with 55 degrees on the other side. Radiographs show preserved glenohumeral joint space. Which diagnosis better accounts for this examination?

Accepted Answer

Adhesive capsulitis

Answer

C5 cervical radiculopathy

Answer

Full-thickness supraspinatus tear

Answer

Glenohumeral osteoarthritis

Question 6

“The X-ray says bone-on-bone. Won’t exercise wear the knee out faster?” asks a patient who still walks the dog daily. A strengthening program causes mild soreness that settles the same day, without swelling, locking, or giving way. The patient wants to remain active. Which response best supports appropriate self-management?

Accepted Answer

“Continue strengthening and low-impact exercise, with loads adjusted to your symptoms.”

Answer

“Stop resistance exercise until ordinary walking is entirely pain-free.”

Answer

“Pause the program until an MRI excludes an associated meniscal tear.”

Answer

“Replace strengthening with stretching so the joint is not exposed to additional load.”

Question 7

Radiographs obtained for progressive thigh pain in a 22-year-old show a destructive distal femoral lesion with cortical breakthrough and a soft-tissue mass. No fracture is present. Weight bearing is protected, and a community surgeon offers an open biopsy the next morning. Which action best preserves the patient’s options for definitive treatment?

Accepted Answer

Have the treating orthopaedic-oncology team plan the biopsy.

Answer

Arrange prophylactic intramedullary fixation and obtain tissue during the same procedure.

Answer

Complete systemic staging before requesting orthopaedic-oncology review of the lesion.

Answer

Arrange a local image-guided core biopsy and refer after histology is available.

Question 8

An immunocompetent 36-year-old has a soil-contaminated open tibial fracture. Intravenous antibiotics have been given and operative debridement is being arranged. Records confirm completion of the tetanus primary series and a Tdap dose seven years ago. What tetanus prophylaxis is indicated for this injury?

Accepted Answer

A tetanus-containing booster without tetanus immune globulin.

Answer

A tetanus-containing booster plus tetanus immune globulin because this is an open fracture.

Answer

No tetanus vaccine or immune globulin, because the last vaccine was less than 10 years ago.

Answer

Tetanus immune globulin alone, because the previous vaccine completed active immunization.

Question 9

Six weeks after starting allopurinol for recurrent crystal-proven gout, a patient develops another typical first-metatarsophalangeal flare that began this morning. Serum urate is now 5.4 mg/dL. The patient is afebrile, has normal renal function, takes no interacting medications, and has previously tolerated colchicine. He asks whether the flare means allopurinol should be stopped. Which medication plan is appropriate?

Accepted Answer

Treat the flare with low-dose colchicine while continuing the established allopurinol regimen.

Answer

Hold allopurinol during the flare and resume it after a course of colchicine.

Answer

Increase allopurinol immediately and use the higher dose instead of an anti-inflammatory.

Answer

Replace allopurinol with febuxostat and treat the current flare with colchicine.

Question 10

A 13-year-old boy with obesity has limped for three weeks because of “knee pain.” Knee examination and radiographs are normal. The affected hip has markedly reduced internal rotation and rotates externally as it is flexed. He can still walk without crutches. Which plan addresses the risk posed by these findings?

Accepted Answer

Stop weight bearing and arrange urgent hip imaging and orthopaedic evaluation.

Answer

Begin quadriceps rehabilitation and reassess if the knee pain persists after two weeks.

Answer

Obtain a knee MRI before changing activity restrictions or extending the examination.

Answer

Continue weight bearing as tolerated and arrange a routine pediatric hip appointment.

Free ONP-C Practice Questions

Domain 1: Degenerative Disorders

Question 1

Question 2

Domain 2: Orthopedic Trauma

Question 3

Question 4

Domain 3: Sports Injuries

Question 5

Domain 4: Inflammatory Disorders

Question 6

Domain 5: Metabolic Bone Disorders

Question 7

Domain 6: Congenital/Pediatric Disorders

Question 8

Domain 7: Musculoskeletal Tumors

Question 9

Domain 10: Educator

Question 10

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