3D-printed titanium alloy pad may perfectly repair glenoid bone defect in recurrent shoulder dislocation Patients: Study

One of the frequent causes giving rise to shoulder joint instability with recurrent dislocation, compromised shoulder function, are glenoid bone defects. Traditionally, the management of defects involves reconstruction surgery with the aid of bone grafts or prosthetic implants. Implants have the additional benefit of reducing surgical morbidity, but restoring glenoid surface geometry, in the past, has been always challenging. Now, by using 3D printing technology, customized implants that exactly resemble a patient's anatomy can be created. Therefore, this study aims to evaluate the efficacy of 3D-printed glenoid pads in the restoration of shoulder joint stability in cases of glenoid bone defects.

This study was done on 25 male cadaveric shoulder joints wherein they are divided into five groups for comparative analysis.

• Group A: No bone defect. The glenoid labrum and joint capsule were intact

• Group B: Anterior-inferior bone defect of the shoulder glenoid

• Group C: Installed 3D-printed glenoid pad with a width of 2 millimeters

• Group D: Installed 3D-printed glenoid pad with a width of 4 millimeters.

• Group E: A 3D-printed glenoid pad 6 mm in width was installed.

The primary outcomes measured included the distance that the humeral head moved forward during glenohumeral dislocation and the maximum load required to induce shoulder dislocation. The stability of the shoulder joint was evaluated by these measurements.

Key Findings

• The shoulder joint stability and humerus displacement were significantly lower in Groups B (bone defect) and C (2 mm pad) compared with Group A (intact glenoid) (p < .05), indicating that a 2 mm pad alone does not fully restore joint stability.

• In Group D (4 mm pad), shoulder joint stability was significantly improved compared with Group A (p < .05).

• However, there was no significant difference in humerus displacement between Groups D and A (p > .05), suggesting that a 4 mm pad offers substantial stability without increasing humerus displacement.

• In Group E, the 6 mm pad significantly increased shoulder joint stability and reduced humerus displacement compared with Group A (p < .05). These findings showed that the 6 mm pad offered the optimum stability with the least humeral head movement.

3D-printed technology has various advantages when used in shoulder surgery. This technology is associated with the personalization of the implants according to the anatomy of the patients and therefore could help gain better stability of the joint. Surgeons may consider conducting further implementation of the 3D printed glenoid pads, particularly those with a width of 2 mm greater than the original glenoid, if they want to create better outcome for patients who have anterior inferior glenoid bone defects. This technology, however, needs further studies in the live patient setting to fashion its appropriate application.

The study shows that 3D-printed glenoid pads, mainly those with a width of 2 mm more than the original glenoid, could generally increase the stability of the shoulder joint where there are bone defects. Results support the integration of 3D-printed technology in orthopedic interventions as a way of restoring joint function in a customizable and accurate way.

Reference:

Huang, D., Wang, J., Ye, Z., Chen, F., Liu, H., & Huang, J. (2024). Biomechanical study of 3D-printed titanium alloy pad for repairing glenoid bone defect. Journal of Orthopaedic Surgery (Hong Kong), 32(2). https://doi.org/10.1177/10225536241257169