Morphological characteristics of the repaired labrum according to glenoid location and its clinical relevance after arthroscopic bankart repair: Postoperative evaluation with computed tomography arthrography

摘要

Background: There have been no studies on the postoperative morphological characteristics of the restored labrum at different glenoid locations and its clinical relevance after arthroscopic Bankart repair with suture anchors. Purpose: To analyze the morphological characteristics of the restored labrum at different locations of the glenoid and their relevance to clinical outcomes as well as affecting factors and to trace the inserted suture anchors after arthroscopic Bankart repair using computed tomography arthrography (CTA). Study Design: Case series; Level of evidence, 4. Methods: A total of 46 patients (mean age, 26.5 ± 6.8 years) who underwent arthroscopic Bankart repair with absorbable suture anchors were enrolled in this study. Patients underwent CTA preoperatively and 6 months postoperatively as well as functional outcome evaluation preoperatively and at the last follow-up (>24 months) with the Rowe score and visual analog scale for pain. Labral height and width were measured on conventional axial CTA images at the 3-, 4-, and 5-o'clock positions twice by 2 raters. The postoperative measurements were also compared with those of the healthy anterior labrum, acquired from the same CTA examination of 32 consecutive patients (mean age, 26.5 ± 8.5 years) with superior labral lesions in the same study period. The postoperative difference in the measurements and between clock positions, and the relationship between the measurements and the clinical factors and functional outcomes, were evaluated. In addition, the locations of all suture anchors were traced on each CTA image, and outcomes according to the locations of the most inferior suture anchors were assessed. Results: The interobserver and intraobserver reliabilities of measurements at each location were excellent (Pearson correlation coefficient = 0.773-0.988). Of the 46 patients, 2 (4.35%) had redislocations after surgery. Postoperative labral height and width were significantly increased at all locations (all P < .001) up to a level similar to the healthy anterior labrum, with significantly larger values at the inferior location compared with the superior location (all P < .05). Patients who had a greater frequency of dislocations before surgery showed a lower postoperative labral height at the 5-o'clock position (P = .012), and this correlated with postoperative instability and poor functional outcomes by the Rowe score (P = .036). In most patients (41/46; 89.1%), the tips of the lowest suture anchors perforated the far cortex, and these anchors were mostly located below the 5-o'clock position (32/41; 78.0%). However, perforation of the far cortex did not affect functional outcomes. Conclusion: Surgeons should be cautious of restoring labral height at the inferior glenoid location for successful arthroscopic Bankart repair. In addition, attention should be given to inserting the lowest suture anchor regardless of clinical significance.