Tracion MRI による修復腱板の評価 Assessment of Postoperative Rotator Cuff by Traction MRI
Postoperative imagings have the following problems: 1)partial volume averaging of subacromial sp ace.2)Difficult visualization of repaired cuffs especially in the early postoperative period. Therefore, we developed a new system named Traction MRI to produce a clear visualization of the tendons.<BR>Primarily repaired rotator cuffs of 113 patients (115 shoulders), aged from 20 to 77 (mean 55) were evaluated from 3 to 12 months after surgery. Preoperative tears were 93 complete (58 small and 35large) and 22 incomplete tears (13 bursal side,5 intratendinous,4 articular side). The operative methods adopted were 96 tendon to bone,10 tendon to tendon and 9 tendon to bone plus fascial patch pro cedures.<BR>MRI was performed with a 1.5T Signa unit. A Traction MRI device made of vinyl chloride was attached to the table and 3 kg weight was applied to each upper extremity and maintained during exa minations.<BR>All 115 repaired tendons were observed with a Traction MRI. High signal intensity was seen in tendons in 42% of the shoulders at 3 months, and this rate decreased to 25% at 6 months and 20% at 12months. Low signals were seen in only 38% at 3 months, and increased to 47% at 6 months and 60%at 12 mouths. In the bursa, high signals were seen in 61% at 3 months, and this rate decreased to 46%at 6 months and 41% at 12 months. In the shoulder joint, high signals were seen in 60% at 3 month s, which went down to 41% at 6 months and 33% at 12 months.<BR>Comparing the postoperative signal intensity and the JOA shoulder score, when the high signal was present, the score tended to be lower than the average. However, there was no statistical difference among the three groups.<BR>When we view the consecutive imagings of the repaired cuffs, high signals were observed in 42% at 3 months.65% of these cases still had high signals at 12 months, while 23% returned to the low sig nals. Out of the 20% cases with intermediate signals at 3 months,86% returned to the low signals after 12 months. All the cases with low signals at 3 months, kept the low intensity throughout the postoperative course. These findings suggest that retearing of tendons occurs in the early stage (within 3months) after surgery.
- 肩関節 = Shoulder joint
肩関節 = Shoulder joint 23(2), 281-284, 1999-07-30