Risk factors for increased external rotation deficit after combined Bankart repair and remplissage for recurrent anterior shoulder instability.

BACKGROUND

External rotation (ER) deficit following Bankart repair and remplissage (BRR) is reported to be a major concern. The purpose of this study was to identify potential risk factors that correlate with increased postoperative ER deficit in a population that underwent BRR for recurrent anterior shoulder instability and glenoid bone loss (<20%).

METHODS

A retrospective analysis of prospectively collected data was performed on 41 patients who underwent BRR for anterior shoulder instability with glenoid bone loss of <20%. Inclusion criteria were a minimum of 2-year postoperative follow-up with available pre- and postoperative functional scores (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES] score and Western Ontario Shoulder Instability Index [WOSI]) and preoperative magnetic resonance imaging. Regression analysis was conducted to detect risk factors for postoperative ER deficit, including age, sex, number of dislocations, length of follow-up, Hill-Sachs interval (HSI), Hill-Sachs depth (HSD), sport participation, number of anchors used for remplissage, and hand dominance. A subanalysis was undertaken after dividing patients into 2 groups (deficit <20% and ≥20%). Correlation between postoperative scores and ER deficit was performed.

RESULTS

All patients showed marked improvement in postoperative WOSI and ASES compared to preoperative by a mean difference of 46.2 ± 19.9 and 29.6 ± 14.4, respectively. Compared with the opposite side, the mean reduction in external rotation at the side (ERs), external rotation in abduction (ERa), forward flexion, and internal rotation in abduction were 21.9% ± 15.5%, 14.3% ± 9.9%, 2.7% ± 1.9%, and 10% ± 6.2%, respectively. Univariate regression analysis showed that shorter postoperative time, larger HSI, and the use of 2 anchors were significantly associated with increased limitation of both ERs and ERa. Participation in sports was significantly associated with less ERs limitation. HSD was significantly associated with increased ERa limitation. Multivariate regression analysis revealed that larger HSI was significantly associated with increases in both ERs and ERa limitation. Time of final follow-up and number of anchors were significantly associated with ERs and ERa limitation, respectively. ER deficit ≥20% was significantly associated with a lower number of preoperative dislocations, shorter time of final follow-up, HSI, and 2 anchors used in remplissage. No correlations exist between functional scores and ER deficit. There were no recurrent dislocations.

CONCLUSION

The results show that postoperative ER deficit improves over time. Risk factors for increased postoperative ER deficit are larger HSI and use of more than 1 anchor for capsulotenodesis. There was no correlation between functional scores and ER deficit.