Is written or verbal consent required to perform a knee arthrocentesis?

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Last updated: November 11, 2025View editorial policy

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Consent Requirements for Knee Arthrocentesis

Informed consent (either written or verbal) is required for knee arthrocentesis, and it must be obtained and documented according to local institutional policies, with the key requirement being that the patient is fully informed about the procedure's nature, benefits, and risks. 1

Form of Consent: Written vs. Verbal

The 2021 EULAR guidelines explicitly state that whether informed consent should be oral or written is determined by local institutional habits and regulations, as there was no preferred option identified in their patient survey. 1 The critical element is not the format but rather that:

  • The patient must be fully informed of the nature of the procedure, the injectable substance being used, and potential benefits and risks 1
  • Consent must be obtained and documented according to your institution's standard practices 1
  • The documentation should reflect the shared decision-making process that occurred 1

Essential Information to Provide

Regardless of whether you use written or verbal consent, you must communicate: 1

  • The nature of the arthrocentesis procedure itself
  • The potential benefits (pain relief, diagnostic information, improved range of motion)
  • Side effects and risks (including the 2.6% risk of vasovagal reactions) 1
  • Post-procedure care instructions

Emergency Situations

In emergency circumstances where full written consent is not feasible, verbal consent is acceptable but must be fully documented in the medical record. 1 If the patient lacks capacity and verbal consent cannot be obtained in an emergency, the action taken must be the least restrictive of the patient's future options. 1

Practical Implementation

The consent process should occur with sufficient time for the patient to consider the information, not immediately before the procedure when the patient may feel vulnerable. 1 For outpatient procedures, providing written information in advance allows patients time to read, evaluate, and formulate questions. 1

Common Pitfall to Avoid

Do not obtain consent for the first time in the procedure room or immediately before needle insertion—this does not allow adequate time for informed decision-making and may render the consent invalid. 1 The consent discussion should ideally occur during the clinical encounter when arthrocentesis is first recommended, with confirmation on the day of the procedure. 1

Documentation Requirements

Whatever form of consent you use, your documentation must include: 1

  • That the patient was informed about the procedure's nature, benefits, and risks
  • That the patient had opportunity to ask questions
  • That the patient's concerns were addressed
  • The patient's decision to proceed (or decline)

In summary: Both written and verbal consent are acceptable for knee arthrocentesis—follow your local institutional policy, but always ensure the patient is adequately informed and the consent process is properly documented.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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