Reverse shoulder arthroplasty for proximal humeral fracture in the elderly. Cemented or uncemented stem?

Reverse Shoulder Arthroplasty for Proximal Humerus Fractures: A Review of Current Evidence

PURPOSE OF REVIEW

The aim of this review is to summarize information published in the recent peer-reviewed literature on reverse shoulder arthroplasty (RSA) for proximal humerus fractures.

RECENT FINDINGS

Although there is still some debate regarding which may be the best treatment for proximal humerus fractures in certain age ranges, RSA seems to offer more predictable results than other surgical treatments for elderly patients. Successful tuberosity healing seems to correlate with better outcomes. Recent trends indicate interest in cementless fixation, fracture-specific stems and a 135-degree polyethylene opening angle. RSA provides a successful surgical solution for selected proximal humerus fractures. Indications, design features, and surgical execution have continued to evolve over the last few years.

Do the humeral radiographic changes at 5-year follow-up affect the clinical outcomes of press-fit humeral stems in primary reverse shoulder arthroplasties?

INTRODUCTION

The purposes of this study were to analyze and compare the functional outcomes and radiological changes around the press-fit humeral components in two contemporary medialized reverse total shoulder arthroplasty (RTSA) systems at a minimum of 5-year follow-up.

MATERIALS AND METHODS

Between December 2003 and December 2015, 249 consecutive RTSAs were performed at our hospital. Of these, 68 primary uncemented RTSA met our inclusion criteria. The Constant-Murley score (CMS), the modified Constant score, a visual analog scale (VAS) and active shoulder range of motion (ROM) were measured pre- and postoperatively. Radiological assessment was performed by plain radiographs at a minimum of 5 years postoperatively.

RESULTS

At a mean follow-up of 80.2 months, there was no significant difference (p = .59) between the postoperative functional scores and range of motion of the two groups (Delta Xtend and Lima SMR). Radiological data of stress-shielding were observed in 38 patients (55.9%) being slightly more frequent in the Lima SMR group (21 patients) than in the Delta Xtend group (17 patients) (p = .62).

CONCLUSIONS

Our study shows that the good functional results are similar between the two uncemented RTSA systems used and that they do not depend on the presence of radiological changes (stress-shielding) in the humeral stem at a minimum 5-year follow-up.

Stress shielding: short-term radiological results of the reverse shoulder arthroplasty with an anatomic proximal coated stem in proximal humeral fractures

PURPOSE

This study aims to determine the stress shielding and other radiological outcomes of patients who underwent an uncemented reverse shoulder arthroplasty (RSA) with an anatomic proximal coated stem for complex proximal humeral fractures (PHF) with 3 or 4 parts at 2 years postoperatively.

METHODS

37 shoulders underwent an uncemented RSA for PHF from November 2015 to February 2019 and were followed up for 2 years. A radiographic assessment of stress shielding, filling ratio, stem stability (radiolucent lines/subsidence/alignment), tuberosity healing and notch was performed.

RESULTS

The mean age at the time of surgery was 72 years (range, 61-85). Stress shielding was appreciated in 31 shoulders (83.8%). The most important characteristic of stress shielding is cortical resorption: Grade 3 resorption occurred in 3 shoulders (8.1%) and grade 4 in 23 (62.2%) as per the grading system defined by Inoue et al. (Inoue et al. in J Shoulder Elbow Surg 26:1984-1989, 2017). A high occurrence of bone resorption was observed in Gruen zones 2 (Lateral Stress shielding) and 7 (Medial Stress shielding). The mean distal filling ratio in patients without stress shielding was 78,48(SD 14,9), whereas in patients with stress shielding, it was slightly higher with a mean of 81,68% (SD 4,89). Tuberosity healing was found in 94.6% (35/37) of the shoulders. No patient had any radiolucent line. No notch was observed.

CONCLUSION

At short-term follow-up, a high rate of tuberosity healing was achieved (94.6%) even though stress shielding was found in 83.8% (31/37) of the shoulders. Bone resorption was most frequently observed externally at zone 2 (Lateral stress shielding) and internally at zone 7 (Medial stress shielding). A higher filling ratio was associated with an increased occurrence of stress shielding. The uncemented anatomic humeral component did not result in early loosening.

LEVEL OF EVIDENCE

IV; Case Series; Treatment study.

The effects of length and width of the stem on proximal humerus stress shielding in uncemented primary reverse total shoulder arthroplasty

INTRODUCTION

To preserve humeral bone during RTSA, stems have been made shorter and cement avoided whenever possible. However, with the increased use of uncemented RTSA, a phenomenon comparable to the stress shielding of the hip has been described for the proximal humerus. The aim of this study was to investigate the influence of stem length and width on proximal humeral bone resorption after primary uncemented RTSA.

MATERIALS AND METHODS

The prospective shoulder arthroplasty database of our institution was reviewed for all primary uncemented RTSAs from 2017 to 2020 in osteoarthritis and cuff tear arthropathy cases with > 2-year follow-up. We compared the clinical and the radiographic 2-year outcome of the short and standard length stems of the same prosthesis design. This allowed us to assess the effects of stem length and width with regard to stress shielding. Furthermore, we defined a cut-off value for the filling ratios to prevent stress shielding.

RESULTS

Fifty patients were included in the analysis, nineteen were in the short stem group (SHORT) and thirty-one in the standard stem group (STANDARD). After 2 years, SHORT showed a relative Constant Score of 91.8% and STANDARD of 98.3% (p = 0.256). Stress shielding was found in 4 patients (21%) in SHORT and in 16 patients (52%) in STANDARD (p = 0.03); it occurred more frequently in patients with higher humeral filling ratios (p < 0.05). The calculated cut-off to prevent stress shielding was 0.7 (± 0.03) for the metaphyseal and distal filling ratio.

CONCLUSION

While short and standard stems for RTSA have good results after 2 years, we found a significant negative effect of higher length and width of the stem with regard to stress shielding. Even though the clinical effects of stress shielding have to be assessed, short stems should be chosen with a filling ratio at the metaphyseal and distal position below 0.7.

LEVEL OF EVIDENCE (A RETROSPECTIVE CASE-CONTROL STUDY)

III.

A novel "7 sutures and 8 knots" surgical technique in reverse shoulder arthroplasty for proximal humeral fractures: tuberosity healing improves short-term clinical results

BACKGROUND

Complex proximal humeral fractures (cPHFs) represent an important public health concern, and reverse shoulder arthroplasty (RSA) has emerged as a feasible treatment option in the elderly with high functional demands. Recent studies have shown that tuberosity healing leads to better clinical outcomes and an improved range of motion. However, the best surgical technique for the management of the tuberosities is still a topic of debate. The purpose of this retrospective observational study is to report the radiographic and clinical outcomes of a consecutive series of patients who underwent RSA for cPHFs using a novel "7 sutures and 8 knots" technique.

MATERIALS AND METHODS

A consecutive series of 32 patients (33 shoulders) were treated with this technique by a single surgeon from January 2017 to September 2021. Results at a minimum follow-up of 12 months and a mean ± SD follow-up of 35.9 ± 16.2 (range 12-64) months are reported.

RESULTS

The tuberosity union rate was 87.9% (29 out of 33 shoulders), the mean Constant score was 66.7 ± 20.5 (range 29-100) points, and the mean DASH score was 33.4 ± 22.6 (range 2-85) points.

CONCLUSIONS

The "7 sutures and 8 knots" technique, which relies on three sutures around the implant and five bridging sutures between the tuberosities, is a relatively simple procedure which provides a reliable means for anatomic restoration of the tuberosities and allows functional recovery of the shoulder in elderly patients with cPHFs treated with RSA.

LEVEL OF EVIDENCE

IV; retrospective atudy.

TRIAL REGISTRATION

At our institution, no institutional review board nor ethical committee approval is necessary for retrospective studies.

Cemented vs. uncemented reverse total shoulder arthroplasty for the primary treatment of proximal humerus fractures in the elderly-a retrospective case-control study

BACKGROUND

Uncemented reverse total shoulder arthroplasty (RTSA) for the primary treatment of proximal humerus fractures (PHF) in elderly patients was introduced at our institution in 2017. Recent reports have raised concerns about increased rates of early bone resorption at the proximal humerus with uncemented fracture stems. The aim of this study was to find out whether there was any difference in functional or radiographic outcomes between cemented and uncemented RTSA for PHF.

METHODS

Seventeen consecutive patients who underwent uncemented RTSA (group nC) in 2017 and 2018 were age and sex matched (propensity score matching 1:2) to 34 patients with cemented RTSA implanted between 2011 and 2016 (group C) for the primary treatment of PHF. These two groups were compared in terms of clinical and radiographic outcomes at 2 years after the index surgery.

RESULTS

The mean bone quality was low in both groups: in group nC the deltoid tuberosity index (DTI) was 1.43 (1.22-1.72) and in group C 1.42 (1.22-1.67). At the final 2 year follow-up, the relative CS was 98.3% (71-118) in group nC and 97.9% (36-125) in group C (p = 0.927); the absolute CS was 70.2 (49-89) in group nC and 68.0 (30-94) in group C (p = 0.509). Lucent lines at the humeral site were seen in 8 cases (47%) in group nC and in 13 cases (38%) in group C (p = 0.056). Compared to 3% in group C, all patients in group nC showed at least grade 1 and 65% showed grade 3 bone resorption at the proximal humerus (p < 0.001).

CONCLUSION

Compared to cemented RTSA bone resorption at the proximal humerus was significantly more frequent in patients with uncemented RTSA for PHF. So far, this is rather a radiographic than a clinical finding, because both groups showed very satisfying functional outcomes and low revision rates at the 2 year follow-up.

LEVEL OF EVIDENCE III

A retrospective case-control study.

Clinical outcomes of cemented vs. uncemented reverse total shoulder arthroplasty for proximal humerus fractures: a systematic review

BACKGROUND

Reverse total shoulder arthroplasty is an established treatment method for comminuted proximal humerus fractures. Both cemented and uncemented techniques exist, with uncemented reverse total shoulder offering many theoretical advantages, including improved biologic fixation, absence of cement related complications, and ease of revision if necessary. There are few studies comparing the outcomes of the two techniques.

METHODS

The study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A search for studies assessing clinical outcomes of reverse total shoulder arthroplasty for proximal humerus fractures was performed of PubMed, Embase, Web of Science, and Cochrane Library. Main outcomes included Constant Score (CS), American Shoulder and Elbow Surgeons (ASES) score, and complication rate. Inclusion criteria were as follows: indication for arthroplasty was fracture; minimum one year follow up; article in English. Exclusion criteria were as follows: review articles; biomechanical or cadaver studies. Quality analysis was performed using the Cochrane Risk of Bias tool (RoB 2) and the Risk of Bias in Non-randomized Studies-of Interventions (ROBINS-I) tool.

RESULTS

A total of 682 studies were identified through the initial search, with 36 studies meeting all inclusion criteria. There were 24 studies investigating cemented technique, 10 studies examining uncemented technique, and two studies involving both techniques. There was no difference in mean follow up between patients receiving a cemented vs. uncemented rTSA (32.3 months vs. 30.6 months, p = 0.06). Patients who received a cemented rTSA had a significantly higher Constant-Murley score than those who received an uncemented rTSA (59.4 vs 55.9, p < .001). There was no difference between the two groups when comparing ASES Scores (77.5 vs 78.6, p = 0.54) and overall complication rates (11.1% vs 11.8%, p = 0.23).

CONCLUSION

Both cemented and uncemented rTSA are both valid options for treating acute proximal humerus fractures. Cemented rTSA may portend slightly improved clinical outcomes with similar overall complication rates compared to uncemented rTSA for proximal humerus fractures.

The Evolution of Reverse Total Shoulder Arthroplasty and Its Current Use in the Treatment of Proximal Humerus Fractures in the Older Population

Proximal humerus fracture (PHF) is a common injury in the older population. While the majority of these fractures are treated non-operatively, a small subset of patients may benefit from surgical treatment. However, there continues to be an ongoing debate regarding the indications and ideal surgical treatment strategy. The use of reverse total shoulder arthroplasty (RTSA) has resulted in a paradigm shift in the treatment of PHFs in the older population. Unique biomechanical principles and design features of RTSA make it a suitable treatment option for PHFs in the older population. RTSA has distinct advantages over hemiarthroplasty and internal fixation and provides good pain relief and a reliable and reproducible improvement in functional outcomes. As a result, there has been an exponential increase in the volume of RTSA in the older population in last decade. The aim of this paper is to review the current concepts, outcomes and controversies regarding the use of RTSA for the treatment of PHFs in the older population.

Clinical Outcomes of Two-Stage Implantation in Reverse Shoulder Arthroplasty for Postinfectious End-Stage Glenohumeral Arthritis in Native Shoulders: A Single-Center Cohort Study with a Minimum 2-Year Follow-up

Background

Septic arthritis of the shoulder is a rare but devastating condition that may lead to joint destruction. There are few studies and limited outcome data on shoulder arthroplasty for infected native shoulders with end-stage glenohumeral arthritis (GHA). Hence, this study aimed to demonstrate the clinical outcomes of two-stage implantation in reverse shoulder arthroplasty (RSA) using an antibiotic spacer in the first stage for this challenging condition.

Methods

We conducted a retrospective study on two-stage implantation in RSA in infected shoulders. Patients were diagnosed with end-stage GHA due to primary shoulder sepsis or infection following non-arthroplasty shoulder surgery. Laboratory data, range of motion (ROM), and functional scores including American Shoulder and Elbow Surgeons score, Constant score, and Disabilities of the Arm, Shoulder and Hand score were assessed prior to spacer placement and at the latest follow-up. Furthermore, intraoperative and postoperative complications were recorded.

Results

In this study, 10 patients with a mean age of 54.8 ± 15.8 years (range, 30-77 years) were included. The mean follow-up period was 37.3 ± 9.1 months (range, 25-56 months). All postoperative ROM measurements and functional scores were improved significantly. Although no reinfection was observed, a total of 5 complications including 2 hematomas, 1 intraoperative humeral fracture, 1 humeral stem loosening, and 1 anterior deltoid dysfunction were observed in 4 patients after a follow-up period of at least 2 years after RSA.

Conclusions

Two-stage implantation in RSA is an effective method for improving the function and controlling the infection in postinfectious end-stage GHA in native shoulders.