Variability of Reporting Recurrence After Arthroscopic Bankart Repair: A Call for a Standardized Study Design

Abstract

Background: High recurrence rates have been reported after anterior shoulder dislocations, regardless of the treatment utilized. However, the definition of recurrent instability has been inconsistent, making a comparison between studies difficult.

Purpose: To report on the nature with which the rate of recurrent instability is reported after arthroscopic Bankart repair, across all levels of evidence, and to analyze factors that may affect the reported rate of recurrence.

Study design: Systematic review; Level of evidence, 4.

Methods: A systematic review of the literature was performed by searching PubMed, the Cochrane Central Register of Controlled Trials, Embase, and ClinicalTrials.gov for studies published within the dates of January 2008 and September 2018. Studies in English that reported on the recurrence of instability after arthroscopic Bankart repair for anterior shoulder instability were considered for inclusion in this review. A meta-regression was performed to test for a linear association between the reported recurrence rate and several continuous covariates, including mean age at surgery, mean length of follow-up, attrition rate (loss to follow-up percentage), and percentage of male patients.

Results: A trim-and-fill meta-analysis yielded an estimated overall recurrence rate of 17.4% (95% CI, 14.3%-20.9%). There was a significant difference in the recurrence rate depending on the level of evidence (Q(3) = 10.98; P = .012). Significant associations were found with the recurrence rate through the meta-regression, including a negative association with mean age (P = .009), a positive association with mean follow-up time (P = .002), and a positive association with attrition rate (P = .035).

Conclusion: A call for standardization is necessary for reporting outcomes of anterior instability after arthroscopic Bankart repair, especially with regard to the reporting of recurrence/failure rates, with careful consideration of the effects that may occur from patient demographics and study design. With no current recommendations for deeming failure, we suggest that all forms of instability be accounted for when determining a failed treatment procedure, with future studies placing an emphasis on greater control of the study design.

Keywords: anterior shoulder instability; arthroscopic Bankart; dislocation; failure; recurrence.

Figure 1.

Funnel plot for all studies (black circles), with additional imputed studies generated through the trim-and-fill method (white circles). Significant evidence for funnel plot asymmetry was found (P = .007), indicating possible publication bias.

Figure 2.

A significant negative association was seen in a meta-regression analysis of the mean age of the study cohort and the reported recurrence rate (estimate = –0.087 [95% CI, –0.153 to –0.022]; P = .009).

Figure 3.

A meta-regression identified that the study’s mean follow-up time was significantly positively associated with the reported recurrence rate (estimate = 0.0084 [95% CI, 0.0030-0.0139]; P = .002).

Figure 4.

A meta-regression identified that the study’s attrition rate (percentage lost to follow-up) was significantly positively associated with the reported recurrence rate (estimate = 0.0280 [95% CI, 0.002-0.054]; P = .035).

Figure A1.

Forest plot of the subgroup meta-analysis comparing the recurrent instability rate among levels of evidence.

Figure A2.

Forest plot of the subgroup meta-analysis comparing the recurrent instability rate among recurrence definitions.