Survivorship of Autologous Structural Bone Graft at a Minimum of Two Years when used to address Significant Glenoid Bone Loss In Primary and Revision Shoulder Arthroplasty: A CT and clinical Review.

BACKGROUND: Severe glenoid bone loss remains a challenge in patients requiring shoulder arthroplasty and often requires autogenous bone grafting. The purpose of this study was to assess the integrity of the bone graft at two years in a series of primary and revision shoulder replacements where glenoid bone loss was managed using a structural autograft (humeral head or iliac crest bone graft) in combination with a trabecular titanium implant.

METHODS: Ethical approval was sought and the study has a portfolio study status by the NIHR (17/YH/0318). We contacted patients who had primary and revision shoulder arthroplasty with Lima Axioma TT metal back glenoid with autologous bone graft and were more than two years since their operation. All eligible patients underwent CT evaluation, clinical review and scoring. Early failures of composite fixation and patients who had revision procedures were excluded (2 patients).

RESULTS: Forty-one patients (43 shoulders) with a mean age of 65 years (Range 33-85 years) were reviewed. There were 24 females and 17 males. The average follow-up period was 40 months (range 24 - 59 months). Primary arthroplasty was performed in 24 shoulders whereas 19 shoulders had revision arthroplasty. Twenty-five shoulders had reverse shoulder arthroplasties (RSR) and 18 had anatomical shoulder replacements (ASR). Twenty-four shoulders had graft taken from the humeral head and 19 had iliac crest bone graft, reflecting the numbers of revisions. We used Wrightington classification for porous metal implant and bone graft incorporation. Satisfactory bone graft incorporation (>50%) was seen in 40 shoulders and only 3 patients had <50 % graft incorporation. The scans at 2 years or more showed no significant deterioration in the bone graft from the early postop scans. Average forward elevation improved from 50° (preop) to 98° (range 35-150). The mean improvement in mean Oxford Shoulder Score was 16 (Preop- 15, Postop 31) and the mean improvement in Constant Score improvement was 36 (Preop 12, postop 48). Mean postoperative ASES was 64 (range 30-85) CONCLUSION: The use of trabecular titanium in conjunction with autologous bone graft provides a reliable method of addressing glenoid bone defects in primary and revision shoulder arthroplasty. This graft/trabecular metal composite has been shown to integrate well and remain largely unchanged over a two-year period. A stable base plate is essential in difficult primary and revision arthroplasty situations. The stability of this construct in our series is reflected in the satisfactory outcomes.