Objective To explore the influence of biceps longus tendon sheath effusion on the treatment ofultrasound-guided intra-articular injections in patient with frozen shoulder.MethodsA total of 81 patients with clinicallydiagnosed frozen shoulders were divided into group with tendon sheath effusion of biceps brachii longus and group withouttendon sheath effusion of biceps brachii longus.All patients were underwent ultrasound-guided intra-articular injections

and high-frequency ultrasound examinations were performed to measure axillary recess capsule（ARC）thickness before and2 weeks after the injection

and Constant-Murley shoulder score were evaluated. The results were compared and analyzed.Pearson correlation analysis was used to analyze the correlation between ARC thickness and Constant-Murley shoulder score.ResultsCompared with the results before treatment

the ARC thickness of the two groups was reduced and the Constant-Murleyshoulder scores was increased after treatment.The differences were statistically significan（tall P<0.05）.Compared with the groupwithout tendon sheath effusion after the treatment

the Constant-Murley shoulder score of group with tendon sheath effusion wassignificantly decreased

and the ARC thickness was increased. The difference were statistically significant（both P<0.05）.Pearson correlation analysis showed that Constant-Murley shoulder score was negatively correlated with ARC thickness（r=-0.40

P<0.05）.ConclusionTendon sheath effusion of biceps brachii longus can affect the efficacy of ultrasound-guided intra-articularinjections for frozen shoulder.ARC thickness can be used as a reference index for evaluation of ultrasound-guided intra-articularinjections for frozen shoulder.