Intra- and Inter-rater Agreement on Magnetic Resonance Imaging Evaluation of Rotator Cuff Integrity After Repair.
To investigate the intra- and inter-rater agreement of magnetic resonance imaging (MRI) evaluations of rotator cuff integrity at 6 and 24 months after arthroscopic rotator cuff repair (ARCR).



Three shoulder surgeons reviewed 68 MRI scans from 34 patients who had undergone ARCR and MRI examination at both 6 and 24 months after surgery. Postoperative rotator cuff integrity was investigated by using Owen, Sugaya, and Hayashida classifications to determine whether the rotator cuff was intact or whether there was a partial-thickness retear or full-thickness retear and Burks score to assess tendon appearance. Multirater kappa statistics were used to measure intra- and inter-rater agreement. Kappa values were interpreted according to guidelines adapted from the work of Landis and Koch.



All classifications had similar intra- and inter-rater agreement (κ = 0.14 to 0.67, 0.23 to 0.60, respectively), but no intra- or inter-rater agreement scored "excellent." Inter-rater agreement after ARCR was higher at 24 months (κ = 0.31 to 0.60) than at 6 months (κ = 0.23 to 0.44) in all evaluations. Reviewers identified full-thickness retears with a moderate to good degree of inter-rater agreement in all evaluations, at both 6 months (κ = 0.42 to 0.73) and 24 months (κ = 0.61 to 0.80) after ARCR. However, poor inter-rater agreement (κ = 0.13 to 0.19) was found in the identification of partial-thickness retears in all evaluations at 6 months after ARCR.



Shoulder surgeons showed better intra- and inter-rater agreement in predicting full-thickness tears compared with partial-thickness tears. The inter-rater agreement at 24 months after ARCR was superior to that at 6 months in predicting not only full-thickness retear but also partial-thickness retear. MRI evaluation of rotator cuff integrity at 6 months after ARCR may be less reliable, regardless of which classification system is used.



Level III, retrospective comparative study.
Department of Orthopedic Surgery, Osaka Medical College, Takatsuki, Japan; Department of Orthopedic Surgery, First Towakai Hospital, Takatsuki, Japan. Electronic address: haseomc@gmail.com.
Akihiko
A
Hasegawa
Department of Orthopedic Surgery, Osaka Medical College, Takatsuki, Japan; Department of Orthopedic Surgery, First Towakai Hospital, Takatsuki, Japan.
Teruhisa
T
Mihata
Department of Orthopedic Surgery, Nishinomiya Kyoritsu Neurosurgical Hospital, Nishinomiya, Japan.
Kenji
K
Yasui
Department of Orthopedic Surgery, Shiroyama Hospital, Osaka, Japan.
Takeshi
T
Kawakami
Department of Orthopedic Surgery, Osaka Medical College, Takatsuki, Japan; Department of Orthopedic Surgery, First Towakai Hospital, Takatsuki, Japan.
Yasuo
Y
Itami
Department of Orthopedic Surgery, Osaka Medical College, Takatsuki, Japan.
Masashi
M
Neo
D000368:Aged; D000369:Aged, 80 and over; D001182:Arthroscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012008:Recurrence; D012189:Retrospective Studies; D017006:Rotator Cuff / Q000000981:diagnostic imaging*; D000070636:Rotator Cuff Injuries / Q000000981:diagnostic imaging* / Q000601:surgery*