Survivorship analysis of CAD-CAM total shoulder replacement.

Background: Glenoid bone loss represents a challenge in shoulder arthroplasty and often precludes standard implants. The CAD-CAM total shoulder replacement (TSR) is an option in these cases. This study aimed to assess survivorship and long-term patient outcomes of the CAD-CAM TSR.

Methods: Fifty-eight patients that underwent a CAD-CAM TSR by three surgeons at a single tertiary referral centre between 2009 and 2017 were reviewed. The mean follow-up was 70 months (28-130). Data was collected on survivorship, range of movement, Oxford shoulder score (OSS, 0-48), subjective shoulder value (SSV, 0-100%), pain score (0-10), and overall patient satisfaction.

Results: CAD-CAM TSR was undertaken as a primary procedure in 28% (n = 16) for end-stage arthritis with severe glenoid bone loss, and as a revision procedure in 72% (n = 42). Of the total, 17% (n = 10) required component revision at a mean of 24 months (4x prosthesis loosening, 3x infection, 3x periprosthetic fracture). Forward elevation improved from 45° ± 27° to 59° ± 29° (P = 0.0056), abduction from 43° ± 29° to 55° ± 26° (P = 0.034) and external rotation from 8° ± 11° to 16° ± 14° (P = 0.031). OSS improved from 15 ± 8 to 29 ± 9 (P = 0.0009), SSV from 18 ± 16 to 62 ± 23 (P < 0.0001), and pain score from 8 ± 2 to 2 ± 2 (P < 0.0001). 88% of patients would undergo the procedure again.

Conclusion: CAD-CAM TSR is reserved for complex cases involving severe glenoid bone loss, offering significant improvements in pain and function with overall positive patient satisfaction.