[Short stem shoulder prosthesis : concept and first results]

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

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 follow-up 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 follow-up 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.

RSA, TSA and PyC hemi-prostheses: comparing indications and clinical outcomes using a second-generation modular short-stem shoulder prosthesis

INTRODUCTION

The goal of this study was to provide an insight into the clinical results after modular short-stem shoulder arthroplasty for various indications.

MATERIALS AND METHODS

A consecutive cohort study of 76 patients followed up for 23-55 (mean 31.4) months. 23 anatomical (TSA), 32 reverse (RSA) and 21 hemi-prostheses with a pyrocarbon head (PyC), using a modular short stem with proximal porous coating were implanted. Range of motion, pain and Constant score (CS) were recorded. Comparisons of pre- vs postoperative outcomes, between prosthesis types and indications, were made.

RESULTS

All prosthesis types brought about a significant improvement (p < 0.05) in all measured outcomes. TSA had a significantly higher increase in the CS than PyC and RSA (p = 0.002 and 0.003, respectively). TSA produced superior gains in all ROM compared with RSA (p < 0.02). RSA brought about significantly smaller improvements in internal rotation than TSA and PyC (p = 0.0001 and 0.008, respectively). TSA had greater pain relief than PyC (p = 0.02). TSA with Walch A glenoids seemed to improve more than type B in the CS. PyC patients with Walch B glenoids improved more than Walch A (p = 0.03). When implanted due to Osteoarthritis (OA), PyC had a comparable final outcome to TSA (p = 0.95), although the preoperatively worse TSA patients had a greater improvement in the CS (p = 0.026). The outcome of RSA did not differ between indications, but Walch A glenoids tended to improve more.

CONCLUSIONS

Using a second-generation short-stem shoulder prostheses, TSA achieves the best clinical improvements overall, especially for OA with a Walch A glenoid. Despite refixation of the subscapularis tendon in all cases, RSA has inferior internal rotation than TSA and PyC, suggesting a mechanical limitation. OA, a Walch B glenoid and arthritis caused by instability seem to be ideal indications when considering PyC.

Subsidence of Uncemented Short Stems in Reverse Shoulder Arthroplasty-A Multicenter Study

BACKGROUND

The radiological phenomenon of subsidence following the implantation of uncemented short-stem reverse prostheses (USSP) has not yet been described. The purpose of this study was to describe the rate and potential risk factors for subsidence. We hypothesized that subsidence may be a frequent finding and that a subsidence of >5 mm (mm) is associated with an inferior clinical outcome.

METHODS

A total of 139 patients with an average age of 73 ± 9 years were included. The clinical and radiological outcome was evaluated at a minimum follow-up (FU) of 12 months.

RESULTS

No humeral component loosening was present at a mean FU of 18 (range, 12-51) months. Mean Constant Score (CS) and Subjective Shoulder Value (SSV) improved significantly from 34.3 ± 18.0 points and 37.0 ± 19.5% preoperatively to 72.2 ± 13.4 points and 80.3 ± 16.5% at final FU (p < 0.001). The average subsidence of the USSP was 1.4 ± 3.7 mm. Subsidence of >5 mm was present in 15 patients (11%). No association between a subsidence >5 mm and CS or SSV was found (p = 0.456, p = 0.527). However, a subsidence of >5 mm resulted in lower strength at final FU (p = 0.022). Complications occurred in six cases (4.2%), and the revision rate was 3.5% (five cases).

CONCLUSIONS

Although subsidence of USSP is a frequent radiographic finding it is not associated with loosening of the component or a decrease in the clinical outcome at short term FU.

LEVEL OF EVIDENCE

Level 4, retrospective study.

Short-term results of a second generation anatomic short-stem shoulder prosthesis in primary osteoarthritis

INTRODUCTION

The aim of the study was to evaluate the short-term clinical results of anatomic total shoulder arthroplasty with a short-stem prosthesis in primary osteoarthritis.

MATERIALS AND METHODS

65 shoulders with a mean age of 70 years (range 47-85 years) were available for minimum follow-up of 24 months. Clinical outcome was determined by range of motion, Constant score (CS) age and sex-adjusted Constant score (CS%), and subjective shoulder value (SSV). The influence of six different factors (high bone adaptations, age > 65 years, female gender, dominant side, atrophy of the supraspinatus tendon ≥ grade 2, glenoid type B2/B3) on the clinical outcome was assessed.

RESULTS

At mean follow-up of 37 months (range 24-58 months), the CS improved from 36 ± 8 to 75 ± 12 (p < 0.001). The shoulder flexion (100° ± 21° to 159° ± 19°) as well as the external rotation (3° ± 11° to 43° ± 18°) improved significantly (p < 0.001). Three complications were noted (transient neuropraxia of the radial nerve, subjective instability, hematoma with superficial wound infection) leading to one revision surgery (wound debridement). No stem loosening was observed. High bone adaptation was present in 19 out of 65 shoulders (29%). The clinical outcome was not influenced by high bone adaptations (p ≥ 0.095). Age > 65 years (n = 44) and female gender (n = 38) were associated with worse clinical outcome (p ≤ 0.043).

CONCLUSIONS

In the short term, the clinical results of this anatomical short-stem shoulder prosthesis are encouraging. A low prevalence of high bone adaptations was found without any influence on the clinical outcome and stem loosening was not observed.

Mid-term results of anatomical total shoulder arthroplasty for primary osteoarthritis using a short-stemmed cementless humeral component

Aims

The aim of this study was to evaluate the clinical and radiological outcome of using an anatomical short-stem shoulder prosthesis to treat primary osteoarthritis of the glenohumeral joint.

Patients and Methods

A total of 66 patients (67 shoulders) with a mean age of 76 years (63 to 92) were available for clinical and radiological follow-up at two different timepoints (T1, mean 2.6 years, sd 0.5; T2, mean 5.3 years, sd 0.7). Postoperative radiographs were analyzed for stem angle, cortical contact, and filling ratio of the stem. Follow-up radiographs were analyzed for timing and location of bone adaptation (cortical bone narrowing, osteopenia, spot welds, and condensation lines). The bone adaptation was classified as low (between zero and three features of bone remodelling around the humeral stem) or high (four or more features).

Results

The mean Constant score improved significantly from 28.5 (sd 11.6) preoperatively to 75.5 (sd 8.5) at T1 (p < 0.001) and remained stable over time (T2: 76.6, sd 10.2). No stem loosening was seen. High bone adaptation was present in 42% of shoulders at T1, with a slight decrease to 37% at T2. Cortical bone narrowing and osteopenia in the region of the calcar decreased from 76% to 66% between T1 and T2. Patients with high bone adaptation had a significantly higher mean filling ratio of the stem at the metaphysis (0.60, sd 0.05 vs 0.55, sd 0.06; p = 0.003) and at the diaphysis (0.65 sd 0.05 vs 0.60 sd 0.05; p = 0.007). Cortical contact of the stem was also associated with high bone adaptation (14/25 shoulders, p = 0.001). The clinical outcome was not influenced by the radiological changes.

Conclusion

Total shoulder arthroplasty using a short-stem humeral component resulted in good clinical outcomes with no evidence of loosening. However, approximately 40% of the shoulders developed substantial bone loss in the proximal humerus at between four and seven years of follow-up. Cite this article: Bone Joint J 2018;100-B:603–9.

Is reverse total shoulder arthroplasty a feasible treatment option for failed shoulder arthroplasty? A retrospective study of 44 cases with special regards to stemless and stemmed primary implants

Is reverse total shoulder arthroplasty a feasible treatment option for failed shoulder arthroplasty? A retrospective study of 44 cases with special regards to stemless and stemmed primary implants.

BACKGROUND

Due to humeral or glenoid bone-loss and rotator cuff insufficiency reverse total shoulder arthroplasty often means the only remaining treatment option in revision shoulder arthroplasty. This study investigates the clinical outcome of patients treated with a reverse total shoulder in revision cases with special regard to stemless and stemmed primary implants.

MATERIALS AND METHODS

From 2010 to 2012 60 failed shoulder arthroplasties were converted to reverse total shoulder arthroplasty. Forty-four patients were available for follow-up after a mean of 24 months. Patients were assessed with X-rays, Constant- and ASES Score and a questionnaire about their subjective satisfaction.

RESULTS

The total number of observed complications was seven (16%). Ninety-eight percent of the patients were satisfied with their clinical result. Patients achieved a mean normalized constant score of 70.2% and a mean ASES Score of 65.3. Patients with stemless primary implants achieved a higher normalized constant score than patients with stemmed primary implants (82 vs. 61.8%; p = 0009).

CONCLUSION

Reverse total shoulder arthroplasty provides satisfactory clinical results and a high patient satisfaction in revision shoulder arthroplasty. The complication rate needs to be considered and discussed with the patient prior to surgery. Presence or absence of a stem of revised shoulder arthroplasties interferes with the outcome. LEVEL OF EVIDENCE IV: (Retrospective study).

[Shoulder endoprosthesis in the elderly : Hemiarthroplasty or total shoulder arthroplasty? Anatomic or reverse?]

Implantation of reverse shoulder endoprostheses is becoming more popular for elderly patients besides the well-established standard anatomic endoprostheses. The reasons for this are the increased life expectancy, age-dependent degeneration of the rotator cuff leading to cuff tear arthropathy, posttraumatic disability after failed osteosynthesis and primary reverse fracture arthroplasty. Stemless implants are more frequently used for primary osteoarthritis with the bone quality being the limiting factor. Modern implant systems allow the stepwise extension from bone preserving primary implants to modular and convertible revision implants that allow a partial exchange of components. Revision surgery, especially that of reverse arthroplasty, has limited potential for secondary treatment options and therefore implantation and revision should be performed in specialized treatment facilities.

Clinical and radiological results of a cementless short stem shoulder prosthesis at minimum follow-up of two years

PURPOSE

Uncemented short stem shoulder arthroplasty combines the advantages of a bone-saving implantation with a straightforward revision option. Uncemented humeral long stems can be associated with stress shielding and loosening. Therefore, we analysed the clinical and radiological outcome of a short stem shoulder prosthesis with metaphyseal fixation.

METHODS

This two-centre study included 82 total shoulder arthroplasties in 80 patients with short stem shoulder prosthesis and a cemented polyethylene glenoid performed between 2010 and 2012. Sixty-eight shoulders had primary osteoarthritis, eight shoulders had post traumatic sequelae and six had other diagnoses. Minimum follow-up was two years. Outcome data included the Constant Score (CS), Subjective Shoulder Value (SSV), Pain Scale (0-15) and range of motion. Radiographic evaluation was done in shoulders with primary osteoarthritis in a standard view.

RESULTS

The mean clinical and radiological follow-up was 31.2 ± 7.2 months (20-52). CS improved from 36.7 ± 15.2 % to 90.4 ± 16.4% and SSV improved from 39.4 ± 15.5 points to 85.5 ± 13.2 points (p < 0.0001). Pain was rated as mild or none in 76 shoulders (92.7%) with a mean value of 13.2 ± 2.6. The mean active flexion was 157.0 ± 24.7°, abduction was 152.6 ± 29.1° and the active external rotation was 38.2 ± 14.8° at recent follow-up. Radiographic assessment was done in 44 shoulders. Six shoulders (13.6%) showed features of slight stress shielding at the medial cortex and no stem with subsidence was found. Three glenoids (6.8%) had minor radiolucent lines.

CONCLUSIONS

Uncemented short stem shoulder arthroplasty with a cemented polyethylene glenoid can yield a stable fixation with a good clinical outcome at minimum follow-up of two years.