Nakamura Hidehiro, Gotoh Masafumi, Honda Hirokazu, Mitsui Yasuhiro, Ohzono Hiroki, Shiba Naoto, Kume Shinichiro, Okawa Takahiro
Department of Orthopedic Surgery, Kurume University Medical Center, Fukuoka, Japan.
Department of Orthopedic Surgery, Kurume University, Fukuoka, Japan.
Clin Shoulder Elb. 2022 Mar;25(1):22-27. doi: 10.5397/cise.2021.00507. Epub 2022 Feb 25.
In some patients with rotator cuff tear (RCT), the axial view of magnetic resonance imaging (MRI) shows subtle posterior decentering (PD) of the humeral head from the glenoid fossa. This is considered to result from a loss of centralization that is typically produced by rotator cuff function. There are few reports on PD in RCT despite the common occurrence of posterior subluxation in degenerative joint disease. In this study, we investigated the effect of PD in arthroscopic rotator cuff repair (ARCR).
We conducted a retrospective study of consecutive patients who underwent ARCR at our institute and were followed-up for at least 1 year. PD was identified as a 2-mm posterior shift of the humeral head relative to the glenoid fossa in the axial MRI view preoperatively. The tear size and fatty degeneration (FD, Goutallier classification) were also evaluated using preoperative MRI. Retears were evaluated through MRI at 1 year postoperatively.
We included 135 shoulders in this study. Ten instances of PD (including seven retears) were observed preoperatively. Fifteen retears (three and 12 retears in the small/medium and large/massive tear groups, respectively) were observed postoperatively. PD was significantly correlated with tear size, FD, and retear occurrence (p<0.01 each). The odds ratio for PD in retears was 34.1, which was greater than that for tear size ≥3 cm and FD grade ≥3.
We concluded that large tear size and FD contribute to the occurrence of PD. Furthermore, PD could be a predictor of retear after ARCR.
在一些肩袖撕裂（RCT）患者中，磁共振成像（MRI）的轴位视图显示肱骨头相对于关节盂有轻微的后脱位（PD）。这被认为是由于肩袖功能通常产生的中心化丧失所致。尽管退行性关节病中后脱位很常见，但关于RCT中PD的报道很少。在本研究中，我们调查了PD在关节镜下肩袖修复术（ARCR）中的影响。
我们对在我院接受ARCR并随访至少1年的连续患者进行了回顾性研究。术前轴位MRI视图中，PD被定义为肱骨头相对于关节盂向后移位2毫米。还使用术前MRI评估撕裂大小和脂肪变性（FD，Goutallier分类）。术后1年通过MRI评估再撕裂情况。
本研究纳入了135个肩部。术前观察到10例PD（包括7例再撕裂）。术后观察到15例再撕裂（小/中撕裂组和大/巨大撕裂组分别为3例和12例）。PD与撕裂大小、FD和再撕裂发生率显著相关（各p<0.01）。再撕裂中PD的优势比为34.1，大于撕裂大小≥3 cm和FD分级≥3的优势比。
我们得出结论，大的撕裂大小和FD会导致PD的发生。此外，PD可能是ARCR后再撕裂的一个预测指标。
