10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
These 10 free COSC questions are organized by exam domain, so you can see how each part of the Certified Orthopaedic Surgery Coder blueprint is tested. Reveal the answer and explanation under each question.
Domain 1: Core knowledge areas
Question 1
Eight months after prompt operative treatment of an open Gustilo type II Colles fracture of the left radius, the patient undergoes revision fixation and bone grafting for documented nonunion. The patient has attended regular fracture follow-up since the original operation. There is no infection or implant complication. Complete the diagnosis code S52.532_ for today’s nonunion care.
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Correct answer: A - M - subsequent encounter for an open type I or II fracture with nonunion
Question 2
Five years after a left total hip replacement, a patient is seen in the office for new lateral hip pain. The signed assessment states, “Left hip pain; possible aseptic loosening versus periarticular tendinopathy.” Neither condition nor a causal relationship between the pain and the implant is established today. Further imaging is ordered. How should today’s diagnostic assessment be reported?
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Correct answer: A - Report the documented left hip pain for this unresolved outpatient presentation.
Question 3
At an established patient’s office visit, an orthopaedist treats a nonsevere exacerbation of rheumatoid arthritis affecting the elbow. The physician adjusts a prescription NSAID, orders a CBC, ESR, and CRP to assess inflammatory activity, and has a substantive management discussion with the patient’s external rheumatologist. That discussion is not separately reported. There is no intensive drug-toxicity monitoring, threat to bodily function, or other high-risk management. Which office E/M code and data-element assessment are supported by this medical decision making?
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Correct answer: C - 99214; the data element is extensive.
Domain 2: Surgical coding of upper and lower extremities
Question 4
The scheduled operation is arthroscopic repair of a chronic right rotator cuff tear. After mobilizing the tendon arthroscopically, the surgeon determines that the repair cannot be completed through the portals and converts to an open approach. The cuff repair is completed open; no other arthroscopic therapeutic procedure is completed. For the Medicare professional claim, which cuff-repair reporting is supported, before laterality modifiers?
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Correct answer: C - 23412
Question 5
For an open proximal-ulna fracture involving the olecranon, the surgeon excises devitalized skin, subcutaneous tissue, fascia, and damaged triceps muscle from the communicating traumatic wound. The exposed bone is irrigated but no bone is excised. Fracture fixation is coded separately. The documented debridement is represented by:
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Correct answer: C - 11011
Question 6
A partial medial meniscectomy is performed for an irreparable tear. The surgeon also completes a medically necessary major synovectomy for separately documented proliferative synovial disease in the lateral and patellofemoral compartments. Neither of those compartments receives another arthroscopic procedure. CPT 29881 has been selected for the meniscectomy. What, if anything, may be reported for the additional synovial work under Medicare NCCI?
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Correct answer: D - Add 29876 with an appropriate NCCI-associated modifier for the distinct major synovectomy.
Domain 3: Spine and joint procedures
Question 7
Through one anterior cervical exposure, a surgeon removes disc material and osteophytes to decompress the neural structures at C5-C6 and C6-C7, then completes interbody arthrodesis at both interspaces. No vertebral body is resected. Select the codes for the discectomy/decompression and arthrodesis, excluding instrumentation, interbody devices, and graft services.
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Correct answer: D - 22551 × 1 and 22552 × 1
Question 8
An audit flags CPT 27447 because no patellar implant appears in the supply record. The operation replaced the femoral and tibial surfaces across both medial and lateral compartments of a native knee; the surgeon deliberately retained the suitable native patellar surface without resurfacing it. What is the appropriate charge correction?
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Correct answer: B - Retain 27447; patellar resurfacing is not required for this code.
Domain 4: Casting, splinting, and other orthopaedic services
Question 9
An injection report identifies the right acromioclavicular joint as the needle target. The physician uses real-time ultrasound guidance, retains permanent images, and completes a guidance report. The glenohumeral joint and surrounding bursae are not injected. Disregarding the drug, E/M, and laterality, which procedure-code combination matches both the anatomical target and the documented guidance?
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Correct answer: B - 20606
Question 10
A 43-year-old man without a history of fragility fracture undergoes a technically valid central DXA examination. His femoral-neck T-score is −2.8 and Z-score is −2.4. Interpret these findings using the International Society for Clinical Densitometry’s adult positions.
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Correct answer: D - BMD is below the expected range for age; BMD alone does not establish osteoporosis in this patient.
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