Journal of the American Academy of Orthopaedic Surgeons · IF 2.9 · July 23, 2026 · LoE III
Predictive Factors for Manipulations Under Anesthesia After Total Knee Arthroplasty: An Analysis of 15,139 Cases
Avinash Iyer, Mckenzie Culler, Sagar Telang, Ryan Palmer, Ian A. Jones, Jay R. Lieberman, Nathanael D. Heckmann — University of Southern California
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 anesthesia' (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.
AI summary · from the full text · reviewed by Pukhraj Gaheer, Medical Student, Queen's University before publishing
Why it mattersKnowing 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.
Conclusion strengthConfirms prior evidence
This identifies a risk factor rather than testing a treatment, so it cannot support a change in what we do.
Presenting this at rounds? Start here
- ?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)?
- ?If a patient is young, female, and Black and therefore statistically at higher risk of MUA, how should that information actually change your preoperative counseling or perioperative medication plan, given the authors themselves call for more prospective research before changing practice?