Effects of Glenoid and Humeral Bone Defects on Recurrent Anterior Instability of the Shoulder.

For proper treatment of recurrent anterior instability of the shoulder with a bone defect, the defect size should be assessed preoperatively with three-dimensional computed tomography or magnetic resonance imaging. In general, the risk of postoperative recurrence of instability is estimated on the basis of preoperative imaging of bipolar bone defects: more than 20%-25% glenoid bone loss and off-track Hill-Sachs lesions have been considered risk factors for recurrence. In patients with a glenoid bone defect more than 20%-25%, a bone graft procedure, such as the Latarjet procedure, is preferred regardless of the glenoid track concept, because compared with arthroscopic stabilization procedure, it provides greater postoperative stability. For patients with a borderline glenoid bone defect (around 20%), surgeons should discuss surgical options with the patients, considering their demand and physical activity level. In addition, the surgeon should take care to prevent postoperative instability and long-term complications. Arthroscopic soft-tissue reconstruction including labral repair and capsular plication combined with the additional remplissage procedure is an anatomical procedure and could be considered as one of the primary treatment methods for patients with glenoid bone defects around 20%. Therefore, treatment strategies for recurrent anterior shoulder instability combined with bone defects should be determined more flexibly on the basis of the patient's individual condition.