Early clinical outcomes of restor3D custom three dimensional-printed glenoid components in complex shoulder...

Severe glenoid bone loss in primary or revision reverse total shoulder arthroplasty presents significant surgical challenges. Patient-specific 3D-printed glenoid implants offer customized fixation strategies for complex anatomical deficits, including modified peg designs, additional screws, and proprietary ingrowth surfaces. Despite promising early results, concerns regarding cost, surgical accuracy, and long-term stability remain.

This retrospective study evaluated clinical and radiologic outcomes in patients with severe glenoid bone loss who underwent primary or revision reverse total shoulder arthroplasty with a custom three dimensional-printed glenoid implant (restor3d) by a single surgeon (December 2022-July 2024). Demographics, surgical indications, implant specifications, patient-reported outcomes, imaging, and complications were collected. Patients with and without complications were compared using Mann-Whitney U and Fisher's exact tests.

Eighteen patients (11 women, 7 men; median age 69 years [interquartile range, 67-77]; mean follow-up 18 ± 7 months) were included. Five patients underwent primary surgery and 13 underwent revision procedures, including 7 (39%) staged revisions. Complications occurred in 27.8% of patients: broken inferior or posterior screws (n = 1) and clinical implant failures, including broken central posts or fibrous ingrowth along the post (n = 4). The 4 patients with implant failure required explantation and revision at a mean of 21.7 months. Patients with complications reported greater post-operative visual analog scale pain (P = .051) and worse American Shoulder and Elbow Surgeons scores (P = .075). A greater quantity and longer length of ≥4.5 mm screws were each significantly associated with fewer complications (P = .041 and P = .035, respectively). Total screw engagement volume in bone was significantly greater in constructs without complications versus those with complications (4315 mm³ vs. 2,824 mm³, P = .018).

Custom 3D-printed glenoid implants show potential for addressing severe glenoid bone loss with patient-specific designs that enhance initial stability. Total screw engagement volume was significantly greater in constructs without complications (P = .018). The data would suggest that larger screws are associated with lower complication rates and improved implant stability compared to 4.0 mm screws; however, this may reflect increased residual bone stock rather than a causal relationship. The 27.8% complication rate in this cohort warrants further monitoring. Future studies with larger cohorts are needed to validate these findings and optimize fixation strategies.