A Novel Technique for Impaction Bone Grafting For Humeral Fixation of Cementless Stemless Reverse Total Shoulder Arthroplasty (Rtsa)

Introduction: Reverse TSA is increasingly used in the last decade. Usually performed on elderly patients with cuff tear arthropathy, rheumatoid arthritis or as revision arthroplasty. Often these patients suffer from marked osteoporosis, bone cysts or bone deficiency. We use Impaction bone grafting technique (IBGT) with a metapheseal cementless stemless triple-finned reversed prosthesis to achieve good humeral fixation even in presence of osteoporosis or large bone cysts.

Aim: To describe the impaction bone grafting technique (IBGT) for humeral fixation in stemless rTSA, and report the medium-long term results of stemless rTSA with impaction bone grafting technique (IBGT).

Materials and Methods: Between 2005 - 2013, 232 patients operated with cementless rTSA using IBGT.

181 females, 51 males. Age 74.8 (38-93y). Follow-up from 24 months to 10 years. 193 stemless and 39 stemmed rTSA. The resected humeral head bone was morcellized and impacted into the proximal humerus. The trial implant (punch) used for impaction and formation of a stable implant bed. In the stemmed rTSA cases, the bone graft was impacted to the humeral shaft to achieve immediate rotational stability with the grooved humeral stem.

Results: This technique offered good initial press-fit fixation of the humeral prosthesis in the metaphysis and later biologic bony ingrowth.

Constant score improved from 15.5 to 61.1 points (age/sex adjusted 88.7%), pain score from 3/15 to 12.7/15. Patient satisfaction increased to 8.4/10. Significant improvement in range of motion with 133.5° elevation, 50.4° external rotation and 63.7° internal rotation.

Radiographic evaluation showed good incorporation of the impacted bone graft. No lucencies, subsidence, stress shielding nor implant loosening or migration were evident on the x-rays. Increased bone density around the implant observed.

Conclusion: IBGT provides excellent humeral fixation in cementless triple-finned rTSA, both stemless and stemmed, with improved bone stock.