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(degrees) +/- 27(degrees) to 59(degrees)+/- 29(degrees) (P = 0.0056), abduction from 43(degrees)+/- 29(degrees) to 55(degrees) +/- 26(degrees) (P = 0.034) and external rotation from 8(degrees) +/- 11(degrees) to 16(degrees) +/- ; 14(degrees)(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.