Free Certified Orthopaedic Surgery Coder (COSC) exam Practice Questions

Sample Practice Questions

Try these 10 sample questions from the Certified Orthopaedic Surgery Coder (COSC) exam practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1An operative note describes fusion of a joint. Which procedure term matches that work?

   1. A. Arthroplasty
   2. B. Arthrodesis
   3. C. Arthrotomy
   4. D. Arthrocentesis

   Answer: B

   Explanation: The COSC terminology list states "Arthrodesis—fusion of joint". Fusion therefore corresponds to arthrodesis; the other terms refer to reconstruction, incision, or puncture.

   Reference: 2026 Specialty Study Guide: COSC — CPT Coding Terminology — Printed p. 33, CPT Coding, Terminology

2. 2Which procedure term describes restoration or reconstruction of a joint?

   1. A. Arthrotomy
   2. B. Synovectomy
   3. C. Arthroplasty
   4. D. Arthrodesis

   Answer: C

   Explanation: The guide defines "Arthroplasty—restoration/reconstruction of joint". The other arthro- terms describe incision, puncture, and fusion.

   Reference: 2026 Specialty Study Guide: COSC — CPT Coding Terminology — Printed p. 33, CPT Coding, Terminology

3. 3A surgeon makes an incision into a joint. Which documented term identifies that action?

   1. A. Arthroscopy
   2. B. Arthrodesis
   3. C. Arthroplasty
   4. D. Arthrotomy

   Answer: D

   Explanation: The terminology section says "Arthrotomy—incision into joint". This differs from puncture, fusion, and reconstruction.

   Reference: 2026 Specialty Study Guide: COSC — CPT Coding Terminology — Printed p. 33, CPT Coding, Terminology

4. 4An operative note documents puncture into a joint to withdraw fluid. Which orthopaedic procedure term names that action?

   1. A. Arthrocentesis
   2. B. Arthrotomy
   3. C. Osteotomy
   4. D. Arthrodesis

   Answer: A

   Explanation: The guide states "Arthrocentesis—puncture into joint". The competing terms name incision, reconstruction, and fusion.

   Reference: 2026 Specialty Study Guide: COSC — CPT Coding Terminology — Printed p. 33, CPT Coding, Terminology

5. 5In musculoskeletal terminology, what condition does chondromalacia describe?

   1. A. Abnormal softness of cartilage
   2. B. Bony projections at a joint
   3. C. Inflammation of bone
   4. D. Loss of bone density

   Answer: A

   Explanation: The COSC guide defines "Chondromalacia—abnormal softness of cartilage". The other descriptions correspond to osteophytes, osteitis, and osteoporosis rather than cartilage softening.

   Reference: 2026 Specialty Study Guide: COSC — CPT Coding Terminology — Printed p. 33, CPT Coding, Terminology

6. 6Which anatomical term refers to bony projections from joints?

   1. A. Chondromalacia
   2. B. Osteophytes
   3. C. Osteoporosis
   4. D. Osteoarthritis

   Answer: B

   Explanation: The COSC guide defines "Osteophytes—bony projections from joints". The other terms denote cartilage softening, bone density loss, or degenerative joint disease rather than the projection itself.

   Reference: 2026 Specialty Study Guide: COSC — CPT Coding Terminology — Printed p. 33, CPT Coding, Terminology

7. 7A procedure description ends in the suffix '-ectomy.' What action does that suffix indicate?

   1. A. Incision
   2. B. Fusion
   3. C. Excision or removal
   4. D. Reconstruction

   Answer: C

   Explanation: The guide states "-ectomy—excision, surgical removal". The other choices reflect different procedural suffixes.

   Reference: 2026 Specialty Study Guide: COSC — CPT Coding Terminology — Printed p. 33, CPT Coding, Terminology

8. 8In an operative term, what does the suffix '-plasty' indicate?

   1. A. Fusion of tissue
   2. B. Reconstruction or repair
   3. C. Excision of tissue
   4. D. Incision into tissue

   Answer: B

   Explanation: The guide lists "-plasty—reconstruction, plastic repair, plastic surgery". Fusion, excision, and incision correspond to other suffixes.

   Reference: 2026 Specialty Study Guide: COSC — CPT Coding Terminology — Printed p. 33, CPT Coding, Terminology

9. 9Which structure is the tough, flexible outer ring of an intervertebral disk?

   1. A. Nucleus pulposus
   2. B. Spinal cord
   3. C. Annulus fibrosus
   4. D. Facet joint

   Answer: C

   Explanation: AAOS states "Annulus fibrosus. This is the tough, flexible outer ring of the disk." The nucleus is the center, while the other structures are outside the disk.

   Reference: OrthoInfo Basics: Herniated Disk — Printed p. 1, What parts of your spine are affected?

10. 10Which structure forms the soft, jelly-like center of an intervertebral disk?

    1. A. Annulus fibrosus
    2. B. Nucleus pulposus
    3. C. Vertebral body
    4. D. Spinal cord

    Answer: B

    Explanation: AAOS states "Nucleus pulposus. This is the soft, jelly-like center of the disk." The annulus is the outer ring; a facet joint and spinal cord are distinct structures.

    Reference: OrthoInfo Basics: Herniated Disk — Printed p. 1, What parts of your spine are affected?