Primary reverse shoulder replacement with a short stem: A systematic literature review

Abstract

Background: Total shoulder arthroplasty implant designs have continued to evolve over the years. One recent change has been the shortening of the humeral component to preserve bone stock and to facilitate revision surgery. Despite promising clinical results, radiographic bone adaptions occur frequently in short-stem total shoulder arthroplasty, and limited data exist on short-stem reverse shoulder arthroplasty (RSA). The purpose of this systematic review was to provide an overview about the functional and radiographic outcomes after an uncemented short-stem RSA, as well as identify areas of clinical importance that are underreported in the current literature. Methods: A systematic review of the literature was performed in accordance with the PRISMA guidelines using PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Clinical outcome studies reporting on short-stem RSA outcomes with evidence level I-IV were included. Demographics, clinical and radiological outcomes, as well as complications and revision data were systematically analyzed and described. Results: Ten studies, published between 2014 and 2019, reporting on 555 shoulders with a mean followup of 32 months (range, 20-99.6 months) met the inclusion criteria. For all studies cuff tear arthropathy was the main indication for RSA (36%), followed by primary osteoarthritis (20%). Clinical outcome was reported in nine of ten studies, with range of motion improving in all studies. Six of the seven studies that used the Constant score (CS) demonstrated significant improvement (27.9 points to 69.3 points in weighted means). All studies reported on radiographic changes and bone adaptions. Among these, scapular notching was the most commonly observed (60 out of 327 cases, 18%) but without any described implication on clinical outcomes. No stem loosening was recorded at any final follow-up. A total of 63 complications (12.9%) were reported, with scapula fractures being the most commonly reported complication. Revision surgery was necessary in 24 cases (4.9%). Conclusion: Good clinical results, comparable with long-stem RSAs, are reported at short-term followup for short-stem RSAs. Humeral bone adaptions occur frequently but aseptic stem loosening is not a matter of concern at short-term follow-up. An area of clinical importance that is under-reported is the relation between filling ratio and stem alignment in short-stem RSA.

Complications and revisions in anatomic and reverse short stem shoulder arthroplasty

“…A study by Ascione et al included various diagnoses and a comparable revision rate of 10.0% was found after the implantation of the same type of short stem RSA in 100 cases with a mean follow-up of 32.6 months. Also, the present analysis revealed that the mean time until revision was 53.4 months after the implantation of RSA, which is more than the maximum FU of the most published studies on short stem RSA [ 44 ].…”

“…Furthermore, the study found a revision rate of 12.7% (15 cases) after short stem RSA. Compared to a 4.9% revision rate after short stem RSA in a systematic review with an average follow-up of 20–99.6 months among 10 included studies, the revision rate in this study is somewhat higher [ 44 ]. Also, the reported revision rate in this study appears to be higher than revision rates after standard stem RSA [ 5 , 14 , 17 , 22 , 41 , 50 ].…”

“…Advantages of the new design are seen in the bone stock preserving implantation technique, especially in the event of revision [ 13 , 21 ]. So far, clinical short- to midterm results for both short stem TSA and RSA are promising [ 11 , 32 , 34 , 36 , 44 ]. As a matter of concern, however, some authors reported the risk of stress shielding due to bone adaptions [ 29 , 33 , 35 , 36 , 38 ] and stem subsidence [ 43 ], which might facilitate stem loosening in the future.…”

Multiplanar analysis of proximal humerus anatomy of patients with rotator cuff arthropathy and relevance to reverse shoulder press-fit stems

“… 11 Longer diaphyseal stems increase fixation and stability of the implant while compromising increased bone stock in the setting of revision surgery and potentially leading to higher rates of stress shielding as well as increased osteolysis in the primary setting. 13 , 24 Conversely, short-stem implants not achieving adequate metaphyseal fixation can predispose to component loosening and malalignment as demonstrated in TSA. 3 , 8 In some cases, a short-stem implant combining both diaphyseal and metaphyseal fixation could avoid this issue.…”

“…Authors have reported short-stemmed implants (size, 60-65 mm) to perform with comparable patient reported outcomes and range of motion compared to standard length with similar postoperative alignment, radiographic signs of loosening, and survival free of revision at short-term follow-up. 12 , 24 However, mid- and long-term follow-ups of short-stem RTSA data remain scarce. Although uncommon, short stems exhibit a higher stress level at the metaphysis increasing the risk of fracture in that region.…”