Reconstruction of recurrent shoulder dislocation with glenoid bone defect with 3D-printed titanium alloy pad: outcomes at 2-year minimum follow-up

Abstract

Background: To evaluate the outcome of shoulder arthroscopy-assisted implantation of three-dimensional (3D)-printed titanium pads for recurrent shoulder dislocation with glenoid bone defects.

Methods: From June 2019 to May 2020, the clinical efficacy of 3D printed titanium pad implantation assisted by shoulder arthroscopy, for the treatment of recurrent shoulder dislocations with shoulder glenoid defects was retrospectively analyzed. The American Shoulder and Elbow Surgeons (ASES) shoulder, Rowe, and Constant scores were recorded before surgery and at 3 months, 6 months, 1 year, and 2 years after surgery. 3D computed tomography (CT) and magnetic resonance imaging were used to evaluate the location of the glenoid pad, bone ingrowth, joint degeneration, and osteochondral damage.

Results: The mean age of the 12 patients was 21.4 (19-24) years and the mean follow-up time was 27.6 (24-35) months. The Visual Analog Scale score significantly improved from 5.67 ± 1.98 preoperatively to 0.83 ± 0.58 postoperatively (p = 0.012). The postoperative ASES score was significantly increased to 87.91 ± 3.47 compared with preoperative ASES score (46.79 ± 6.45) (p < 0.01). Rowe and Constant scores also improved from 22.5 ± 12.34 and 56.58 ± 7.59 preoperatively to 90.83 ± 4.69 and 90.17 ± 1.89 at 2 years postoperatively, respectively. CT performed 2 years after surgery showed that the pad perfectly replenished the bone-defective part of the shoulder glenoid and restored the articular surface curvature of the shoulder glenoid in the anterior-posterior direction, and the bone around the central riser of the pad was tightly united. Magnetic resonance imaging 2 years after surgery showed that the humeral head osteochondral bone was intact, and there was no obvious osteochondral damage.

Conclusions: 3D printed titanium pads are a reliable, safe, and effective surgical procedure for treating recurrent shoulder dislocations with glenoid bone defects.

Keywords: 3D-printed titanium alloy pad; Glenoid bone defect; Recurrent shoulder dislocation.

Fig. 1

Preoperative 3D CT images of the affected side (A) and the healthy side (B) in the same case. The arrow indicates 25% anterior glenoid defect

Fig. 2

The 3D model drawing and the physical image of the pad. (A) A front view of the reconstructed pad model from the 3D simulation. (B) A back view of the reconstructed pad model from the 3D simulation. (C) The 3D model drawing of the pad. D. The physical image of the pad

Fig. 3

(A). The arthroscope is viewed from the posterior approach, and the operator stabilizes the 3D printed guide with finger assistance to ensure proper placement of the guide. The arrow indicates 3D printed guide plate. (B) An auxiliary incision of about 4 cm was made anteriorly to the shoulder joint, and the subscapularis muscle was retracted through the rotator interval to expose the anterior bony surface of the glenoid. Under direct vision, the 3D-printed prosthesis was implanted after ensuring that the guide plate was in the correct position. The arrow indicates 3D printed titanium alloy pad. GL, glenoid; HH, humeral head

Fig. 4

3D printed pad mock-up installation. (A) A Kirschner wire was inserted into the middle guide hole of the 3D-printed guide plate. (B) The 4.5 mm hollow drill was used to enlarge the bone channel. (C) The central column of the pad is driven into the shoulder glenoid through the bone channel. (D) Simulation drawing of 3D printing pad after installation

Fig. 5

(A) Arthroscopically observed from the posterior approach, the 3D-printed prosthesis fit the bony surface of the shoulder glenoid and did not appear to be higher than the articular cartilage surface, and the prosthesis was well positioned. (B) Arthroscope from the rear approach, suture the capsule and cover the surface of the prosthesis

Fig. 6

CT and magnetic resonance images of the patient at 2 years postoperatively. (A) CT 3D reconstruction 2 years after surgery showed perfect fit of the pad to the defective portion of the shoulder glenoid without malposition. (B) CT examination 2 years after surgery showed tight bone union around the pad riser, indicating bone ingrowth. (C) Magnetic resonance examination 2 years after surgery showed that the humeral head osteochondral bone was intact without obvious osteochondral damage