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Updated: Feb 14, 2026

Knee Arthrocentesis in Adults
Published on: February 25, 2022
Predictors of arthrocentesis outcome on joint effusion in patients with disk displacement without reduction
Eduardo Grossmann1, Rodrigo Lorenzi Poluha2, Lilian Cristina Vessoni Iwaki3
1Craniofacial Pain Applied to Dentistry, Department of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Objectives:
The aim of this study was to investigate the preoperative variables in patients with articular disk displacement without reduction that may influence the results of arthrocentesis on joint effusion (JE).
Study Design:
The records of 203 patients with clinical signs and symptoms of unilateral painful disk displacement without reduction and JE, confirmed by magnetic resonance imaging (MRI), and treated with arthrocentesis were selected. The following preoperative data were recorded: sex; age; joint side; pain duration; pain intensity, measurement with the visual analogue scale; and maximum interincisal distance (MID). All patients underwent a second MRI examination 3 to 4 months postoperatively to assess JE. The sample was then divided into 2 groups: group 1 (n = 160) comprised patients with no signs of JE; and group 2 (n = 43) comprised patients still showing signs of JE. Univariate and multivariate analyses were used to compare the groups.
Results:
Among the studied variables, pain duration (P = .0175), pain intensity (P < .0001), and MID (P = .0085) were shown to affect arthrocentesis outcomes. The longer the pain duration (odds ratio [OR] = 0.930), the more intense was the pain (OR = 0.346), and the smaller the MID (OR = 0.562), the less were the chances of arthrocentesis completely eliminating JE.
Conclusions:
Pain duration, pain intensity, and MID can be used as predictors for the effect of arthrocentesis on JE outcomes and considered during treatment planning.
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