Determining of the amount of impression defect of the humeral head (Hill-Sachs lesion)

Abstract

In the scientific literature there is not enough description of methods for quantitative evaluation of the defect to determine the severity of lesion, relation between the results of examination and the type of surgery that would be pathogenetically justified for each degree of bone defect of the articular surface of the humeral head is not present. Objective: To develop a method of calculating the amount of preoperative impression defect of the humeral head which will allow to determine the area, depth, width, length and orientation of the defect on the articular surface of the scapula. Methods: We processed the results of CT-scanning in 45 patients with Hill-Sachs lesions using a computer program created by the authors (patent UA № 77 086). All patients were admitted to the SI «Sytenko Institute for Spine and Joints Pathology of the National Academy of Medical Sciences of Ukraine» from 2010 to 2013. Clinical group of patients consisted of 4 women and 41 men. Results: Processing of CT-scans data of patients in the preoperative period showed that in 20 of them defect size was 20–30 %, in 10 less than 20 %, and in 15 — 30–40 % of the articulating surface of the head of the humerus. In patients with 20–30 % defect we performed remplissage of defect with infraspinatus tendon and anterior stabilization of the shoulder joint capsule. In patients with 30–40 % we replaced defect with bone autograft from the wing of ilium followed by stabilization of the anterior capsule of the shoulder joint. In patients with defect less than 20 % of the articulating surface of the head of the humerus we performed only stabilization of the anterior capsule of the shoulder joint. Nearest outcomes in this group of patients we assessed at 12 and 24 weeks after surgery according to Constant scale. Conclusion: The proposed method allows to conduct preoperative planning with individual choice of surgical treatment which will help to reduce the risk of recurrence of dislocations in the postoperative period.