Reverse Shoulder Arthroplasty with a Cementless Short Metaphyseal Humeral Implant without a Stem: Survivorship, Clinical and Radiological Outcomes in a Prospective Study from an Independent Centre

Introduction: The aim of this study is to present the survivorship, functional and radiological outcomes of a novel short metaphyseal reverse total shoulder arthroplasty (rTSA) prosthesis without a diaphyseal stem from an independent centre.

Methods: Patients’ demographics, indications for surgery, complications, functional and radiological assessment at the final follow up as well as survivorship with the end point of revision for any reason were recorded.

Results: Between 2009 and 2016, 35 patients received 36 rTSA, 26 female and 9 male. Mean age was 76.9 years. Indications were: cuff tear arthropathy 22 ; rheumatoid arthritis 5 ; chronic anterior dislocations 2; acute trauma 1 ; fracture sequelae 2 and failed resurfacing prosthesis 4. 28 patients received a standard prosthesis and 8 a stemmed. Mean follow up was 3.2 years. One case was complicated by a deep infection managed with a washout and life long oral antibiotics with retention of the prosthesis. Two patients sustained periprosthetic fractures following trauma, which were managed conservatively with good return of function. There were two revisions for glenosphere dissociation. One patient showed subsidence and early varus tilt of the stem, which stabilized at 2 years. The patient was painfree and functional at the 6 year followup. There were no other complications or revisions. Radiographic analysis showed no lucencies, or stress shielding around the humeral or glenoid components. Glenoid notching was found in 7 shoulders (6 Grade I and 1 Grade II). Activities of daily living with requirement for internal and external rotation score (ADLEIR) was on average 12 preoperatively (range 0 – 27) and 31 postoperatively (range 18 - 36).

Discussion: This short to medium term prospective study demonstrates excellent survivorship and radiological results of this rTSA which requires a simple surgical technique and preserves the bone stock. Our results are similar to the currently published literature.