Reverse shoulder arthroplasty with a short metaphyseal humeral stem

Abstract

Purpose: Reverse shoulder prostheses have been gaining popularity in recent years. A short metaphyseal stem design will allow bone stock preservation and minimize stem related complications. We examined the clinical and radiographic short-term outcome of a short metaphyseal stem reverse shoulder arthroplasty.

Methods: Thirty-one patients, with a mean follow-up of 36 months (24-52), were evaluated clinically with the Constant-Murley score, patient satisfaction and pain relief scores. The fixation of the glenoid and humeral components, subsidence and notching were evaluated on radiographs. The indications were cuff tear arthropathy (22), fracture sequelae (five) and rheumatoid arthritis (four).

Results: The average Constant score improved from 12.7 (range two to 31) pre-operatively to 56.2 (range 17-86) postoperatively. It rose from 13.5 to 58.3 in patients with Cuff arthropathy, from 15.8 to 62.0 in revision arthroplasty, from 10.2 to 47.4 in those with fracture sequelae, and from 11.5 to 55.3 in patients with rheumatoid arthritis. The overall mean patient satisfaction score improved from 2.4/10 to 8.5/10 and mean pain score improved from 0.8/15 to 12.5/15. We found an overall improvement in active forward flexion from 46.8 to 128.5° and from 41.6 to 116.5° in abduction. No humeral loosening or subsidence was observed. Two cases of grade 1-2 glenoid notching were reported. Overall there were three intra-operative fractures that did not affect the operation and healed without affecting the good results. There were five late traumatic periprosthetic fractures, only one of them required a revision surgery to a stemmed implant and the rest healed without surgery. There were two early dislocations that had to be revised.

Conclusions: The clinical and radiographic evaluation of a bone preserving metaphyseal humeral component in reverse shoulder arthroplasty is promising, with good clinical results, no signs of loosening or subsidence.

Fig. 1

Pre-operative X-rays of two patients with cuff arthropathy (a) and rheumatoid arthritis (b)

Fig. 2

Changes in constant score for various indications

Fig. 3

Changes in patient satisfaction for various indications

Fig. 4

Changes in pain score for various indications

Fig. 5

Changes in forward flexion and abduction for various indications

Fig. 6

Changes in external and internal rotation score for various indications

Fig. 7

X-rays of the metaphyseal reverse prosthesis

Fig. 8

a–f X-rays of an acute late traumatic periprosthetic fracture (a) after a couple of falls of the patient, the healing of the periprosthetic fractures (b, c), and the final clinical results (d–f)