BACKGROUND: There is no evidence on which functional levels have to be recovered to return to the preinjury sport at preinjury level, i.e. successful RTS, after open Latarjet procedure. Therefore, this study aimed to identify whether RTS criteria assessed at 4.5 months postoperatively predict successful RTS at 1 year after open Latarjet procedure. METHODS: All patients who underwent an open Latarjet procedure between August 2018 and July 2021 were eligible. At 4.5 months postoperatively, patients completed the Shoulder Instability-Return to Sport after Injury questionnaire, and performed unilaterally with each side maximal isometric strength in glenohumeral internal and external rotation, upper-quarter Y balance test, unilateral seated shot-put test, and modified closed kinetic chain upper extremity stability test. They answered RTS inquiry at 12 months postoperatively. Logistic regressions were applied to assess the ability of ratios based on operated-nonoperated ratios, or on dominant-nondominant ratios, to predict successful RTS. RESULTS: Among 126 eligible patients, 110 answered the RTS inquiry
21 were excluded, 49 patients were included in the successful RTS group, and 40 in the unsuccessful RTS. No ratios based on operated-nonoperated ratios were prognostic factors for successful RTS. Despite a low precision of the model (area under the ROC curve = 0.64), dominant-nondominant ratios in internal rotation strength (Odd-Ratio = 0.98
p=0.02), balance between external and internal rotator strength at the operated shoulder (OR = 1.03
p=0.02) and muscular endurance ability (OR = 1.03
p=0.04) were found prognostic factors for successful RTS. CONCLUSION: The findings challenge the ability of criteria expressing operated shoulder functions with reference to those of the contralateral one in predicting a successful return to sport. They suggest that, when assessed 4.5 months postoperatively, the balance of function between dominant and nondominant shoulders in reference to those of healthy athletes would be better predictors of returning to preinjury sport at the preinjury level. This study highlights that clinicians and sport supervisors may place particular care on recovery in dominant-nondominant balance in maximal internal rotation strength and in upper extremities strength endurance to enhance the likelihood to return to sport successfully for their athletes who underwent anterior shoulder stabilization surgery by open Latarjet procedure.