# Anesthesia modality in arthroplasty: comparator and evidence limits

> **Educational work by a pre-medical student — not medical advice.** Not a clinical protocol, prescription, or patient handout, and not for patient care. See [DISCLAIMER](DISCLAIMER.md).

Independent educational note, revised 27 October 2026. This replaces unverified numerical effects and blanket superiority claims.

[Johnson et al., 2016, PMID 26787787](https://pubmed.ncbi.nlm.nih.gov/26787787/) reviewed randomized and prospective comparative hip/knee arthroplasty evidence. It found a modest length-of-stay difference, while several major outcomes showed no statistically detected difference. Mixed operations, older practice and heterogeneity limit direct application to a current individual TKA pathway.

[ICAROS, 2019, PMID 31351590](https://pubmed.ncbi.nlm.nih.gov/31351590/) includes retrospective and database observational studies as well as randomized evidence and favors neuraxial anesthesia in its consensus recommendations. For knee arthroplasty specifically, the preference is a weak recommendation based on low-level evidence; the hip arthroplasty recommendation was strong. This broader evidence design is relevant when comparing its conclusions with the earlier prospective-study review. It is not proof of universal causal benefit or a mandate for a particular patient.

## Interpretation

- Separate randomized evidence from observational associations and their possible selection/confounding effects.
- Identify the operation, anesthetic technique, analgesic background, thromboprophylaxis, time period and outcome.
- A nonsignificant superiority comparison is not a formal equivalence or non-inferiority result.
- A hip-fracture trial is not direct evidence for elective primary TKA.
- A procedure-specific decision also depends on patient preference, contraindications, clinician expertise and local resources; this note supplies no selection algorithm.

For antithrombotic considerations, consult the [current ASRA guideline index](https://asra.com/guidelines-articles/guidelines), which lists the fifth edition. The historical 2018 fourth edition is not presented as the current dosing/timing authority. No hold interval or patient-care instruction is reproduced here.