Does joint effusion on T2 magnetic resonance images reflect synovitis? Comparison of arthroscopic findings in internal derangements of the temporomandibular joint.
OBJECTIVE
The purpose of this study was to clarify the characteristics of joint effusion (JE) in the temporomandibular joint by comparing T2-weighted magnetic resonance (MR) images with arthroscopic findings.


METHODS
MR images of 47 symptomatic temporomandibular joints (47 patients) with internal derangement associated with painful hypomobility were taken to evaluate the degree of JE on a scale of 0 to 3. Within 2 months after MR images, arthroscopic findings with respect to the severity of synovitis, adhesion, and degenerative change in the superior compartment were each quantitatively assessed on a scale of 0 to 10. The arthroscopic scores were compared among the 4 JE grades, as well as between 2 groups, effusion-present (grades 2 and 3) and effusion-absent (grades 0 and 1), by using the Spearman correlation coefficient and the Mann-Whitney U test.


RESULTS
The distribution of JE was as follows: 10 joints had grade 0, 5 joints had grade 1, 19 joints had grade 2, and 13 joints had grade 3. The synovitis score had a significant relationship to the degree of effusion (P =.0012) and was higher in the effusion-present group (6.4 +/- 2.0) than in the effusion-absent group (4.2 +/- 1.6) (P =.0005) On the other hand, there was no statistically significant correlation between either adhesion or degenerative change and effusion.


CONCLUSIONS
JE may reflect synovitis; however, the nature of JE itself needs to be further elucidated by additional studies.
Segami
N
N
Department of Oral and Maxillofacial Surgery, Kanazawa Medical University, Uchinada, Ishikawa Prefecture, Japan. n-segami@kanazawa-med.ac.jp
Nishimura
M
M
Kaneyama
K
K
Miyamaru
M
M
Sato
J
J
Murakami
K I
KI
D000293:Adolescent; D000328:Adult; D000368:Aged; D018771:Arthralgia / Q000175:diagnosis; D001182:Arthroscopy; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D004204:Joint Dislocations / Q000175:diagnosis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000175:diagnosis; D010147:Pain Measurement; D016059:Range of Motion, Articular; D018709:Statistics, Nonparametric; D013582:Synovial Fluid; D013583:Synovial Membrane / Q000473:pathology; D013585:Synovitis / Q000145:classification / Q000175:diagnosis*; D019224:Temporomandibular Joint Disc / Q000473:pathology; D013705:Temporomandibular Joint Disorders / Q000145:classification / Q000175:diagnosis*; D000267:Tissue Adhesions / Q000175:diagnosis