Learning curve of office-based ultrasonography for rotator cuff tendons tears.
OBJECTIVE
To compare the accuracy of ultrasonography and MR arthrography (MRA) imaging in detecting of rotator cuff tears with arthroscopic finding used as the reference standard.


METHODS
The ultrasonography and MRA findings of 51 shoulders that underwent the arthroscopic surgery were prospectively analysed. Two orthopaedic doctors independently performed ultrasonography and interpreted the findings at the office. The tear size measured at ultrasonography and MRA was compared with the size measured at surgery using Pearson correlation coefficients (r). The sensitivity, specificity, accuracy, positive predictive value, negative predictive value and false-positive rate were calculated for a diagnosis of partial-and full-thickness rotator cuff tears. The kappa coefficient was calculated to verify the inter-observer agreement.


RESULTS
The sensitivity of ultrasonography and MRA for detecting partial-thickness tears was 45.5 and 72.7 %, and that for full-thickness tears was 80.0 and 100 %, respectively. The accuracy of ultrasonograpy and MRA for detecting partial-thickness tears was 45.1 and 88.2 %, and that for full-thickness tears was 82.4 and 98 %, respectively. Tear size measured based on ultrasonography examination showed a poor correlation with the size measured at arthroscopic surgery (r = 0.21; p < 0.05). However, tear size estimated by MRA showed a strong correlation (r = 0.75; p < 0.05). The kappa coefficient was 0.47 between the two independent examiners.


CONCLUSIONS
The accuracy of office-based ultrasonography for beginner orthopaedic surgeons to detect full-thickness rotator cuff tears was comparable to that of MRA but was less accurate for detecting partial-thickness tears and torn size measurement. Inter-observer agreement on the interpretation was fair. These results highlight the importance of the correct technique and experience in operation of ultrasonography in shoulder joint.


METHODS
Diagnostic study, Level II.
Department of Orthopedic Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-701, Korea. ojh8469@naver.com
Ji-Hoon
JH
Ok
Yang-Soo
YS
Kim
Jung-Man
JM
Kim
Tae-Wook
TW
Yoo
D001182:Arthroscopy; D005260:Female; D006801:Humans; D059032:Learning Curve; D008279:Magnetic Resonance Imaging; D008297:Male; D010824:Physicians' Offices; D011237:Predictive Value of Tests; D011446:Prospective Studies; D017006:Rotator Cuff / Q000000981:diagnostic imaging*; D000070636:Rotator Cuff Injuries; D012680:Sensitivity and Specificity; D014463:Ultrasonography