Use of Additive Technologies in Surgical Treatment of Chronic Posterior Dislocations of the Shoulder

The aim of the study was to evaluate the efficiency of additive technologies in surgical treatment of patients with osteochondral defects of the humeral head articular surface against the background of chronic posterior dislocation of the shoulder by means of comparing clinical and radiological results with the McLaughlin procedure.

A prospective randomized comparative group clinical study was conducted, which included 20 patients who in 2019-2021 underwent surgical treatment of chronic posterior dislocation of the shoulder in the Traumatological and Orthopedic Department of the Institute of Traumatology and Orthopedics of the Privolzhsky Research Medical University (Nizhny Novgorod, Russia). Depending on the type of surgery, all patients were divided into 2 groups: group 1 (n=10) was subject to McLaughlin procedure, whereas group 2 (n=10) - to reconstruction of the humeral head using a customized implant based on additive technologies (3D printing). To assess postoperative results, 6 months after the surgery all patients underwent the following procedures: X-ray imaging of the shoulder joint in two projections, CT scanning, and angulometry as well as provided their responses in line with the following questionnaires: Visual Analog Scale (VAS), Disabilities of the Arm, Shoulder and Hand (DASH), American Shoulder and Elbow Surgeons Shoulder Score (ASES), Constant Shoulder Score (CSS), Shoulder Rating Questionnaire (SRQ), and the Hospital for Special Surgery Shoulder Surgery Expectations Survey (Survey of patient, SP).

Both the McLaughlin procedure and the reconstruction of the humeral head using a customized implant made using additive 3D printing technologies increased the range of motion in the shoulder joint, mitigated the pain syndrome and improved the patients' quality of life. During the postoperative period, there were no infectious complications in both groups. The total bed-day in group 1 was 7 [5; 9] days; in group 2, it was 8 [6; 9] days. There was no recurrence of dislocation or progression of osteoarthritis of the shoulder joint in patients in both groups during 6 months after the surgery. The ASES, SP, SRQ, CSS, DASH, and VAS questionnaires assessment for both groups showed a statistically significant improvement for all indicators in the postoperative period. There were no statistically significant differences found between the groups as to the results of angulometry and answering the questionnaires.

Customized implants made using additive technologies can shorten the surgery duration by 1.3 times, whereas the volume of intraoperative blood loss - by at least 1.5 times compared to the McLaughlin procedure.