Predictive Factors for Manipulations Under Anaesthesia After Total Knee Arthroplasty: An Analysis of 15,139 Cases
Journal of the American Academy of Orthopaedic Surgeons · 23 Jul 2026
† Impact is the editorial-priority score. All scores are out of 100. Clinical is a stored clinical-importance score from the earlier method; it has not been recalculated.
Why it matters
Knowing which patients are more likely to develop stiffness after knee replacement could help surgeons counsel patients and consider perioperative anti-inflammatory strategies, even though this is only association-level evidence.
The evidence
This retrospective cohort study used a national database of over 975,000 total knee replacements to find which patients most often needed a later 'manipulation under anaesthesia' (MUA) for postoperative stiffness. About 1.55% of patients (15,139) required MUA, and those patients were more likely to be younger, female, and Black (adjusted odds ratio for Black race 1.98, 95% CI 1.88-2.08), while use of perioperative dexamethasone, daily corticosteroids, and ARBs were linked to lower odds of needing MUA.
Manipulation under anesthesia (MUA) within 90 days of primary TKA: Odds ratio 1.977 (95% CI 1.876 to 2.083; units not reported). Interpret in the study's stated comparison; this alone does not establish a treatment's causal effect.
Why this rigour score?
Retrospective cohort
Methods at a glance
Recorded assessment- Confounding adjustmentMultivariable regression
- Covariate balance confirmedNot reported
- Outcome assessors blindedNot reported
- Comparable start of follow-upMet
- Adequate statistical powerNot applicable
- Prospective registrationNot applicable
Not reported does not mean not done. Checks have different weights; this is not a count of boxes ticked.
How to read this assessment
The recorded methods are shown alongside the published score. A verified point-by-point calculation is not available for this version of the appraisal.
Checklist from the stored appraisal. “Not met” describes the recorded criterion; it does not always produce a deduction. This overview supports reading the full study.
For journal club
1.Because this is a retrospective administrative database study without data on intraoperative technique, implant alignment, or actual ROM measurements, how much of the observed 'protective' effect of medications like dexamethasone or ARBs could instead reflect unmeasured confounding (e.g., healthier patients being prescribed these drugs)?
2.If a patient is young, female, and Black and therefore statistically at higher risk of MUA, how should that information actually change your preoperative counselling or perioperative medication plan, given the authors themselves call for more prospective research before changing practice?
Original publication title
Predictive Factors for Manipulations Under Anesthesia After Total Knee Arthroplasty: An Analysis of 15,139 Cases