Subacromial Balloon Placement Demonstrates No Advantage Over Debridement in the Treatment of Massive Irreparable Rotator Cuff Tears: A Dual-Armed Systematic Review and Meta-analysis of Over 1000 Patients

BACKGROUND

In recent years, the placement of a subacromial balloon (SAB) spacer has emerged as a treatment option for massive irreparable rotator cuff tears (MIRCTs); however, there is significant controversy regarding its utility in comparison with other surgical interventions.

PURPOSE

To compare outcomes after SAB spacer placement versus arthroscopic debridement for MIRCTs.

STUDY DESIGN

Dual-armed systematic review and meta-analysis (level IV evidence).

METHODS

A literature search of PubMed (MEDLINE), Scopus, and CINAHL Complete databases for articles published before May 7, 2022, was conducted to identify patients with MIRCTs undergoing the 2 procedures. For the SAB arm, 14 of 449 studies were considered eligible for inclusion, while 14 of 272 studies were considered eligible for inclusion in the debridement arm.

RESULTS

In total, 528 patients were eligible for inclusion in the SAB arm and 479 patients in the debridement arm, and 69.9% of patients undergoing SAB placement also underwent concomitant debridement. Decreases in the visual analog scale (VAS) pain score and increases in the Constant score were found to be significantly larger after debridement (-0.7 points [P < .001] and +5.5 points [P < .001], respectively), although the Patient Acceptable Symptom State for the VAS was not achieved after either procedure. Both SAB placement and debridement significantly improved range of motion in forward flexion/forward elevation, internal and external rotation, and abduction (P < .001). Rates of general complication were higher after debridement versus SAB placement (5.2% ± 5.6% vs 3.5% ± 6.3%, respectively; P < .001); however, there were no significant differences between SAB placement and debridement in rates of persistent symptoms requiring a reintervention (3.3% ± 6.2% vs 3.8% ± 7.3%, respectively; P = .252) or reoperation rates (5.1% ± 7.6% vs 4.8% ± 8.4%, respectively; P = .552). The mean time to conversion to reverse total shoulder arthroplasty was 11.0 versus 25.4 months, respectively, for the SAB versus debridement arm.

CONCLUSION

While SAB placement was associated with acceptable postoperative outcomes in the treatment of MIRCTs, there was no clear benefit over debridement alone. Shorter operative times coupled with better postoperative outcomes and longer times to conversion to reverse total shoulder arthroplasty rendered debridement a more attractive option. While there may be a role for SAB placement in poor surgical candidates, there is burgeoning evidence to support debridement alone without SAB placement for the treatment of MIRCTs.

Subacromial Balloon Spacer Implantation for Massive Irreparable Rotator Cuff Tears Is Associated With Restoration of the Acromiohumeral Interval and Glenohumeral Center of Pressure: A Systematic Review and Meta-Analysis of Controlled Laboratory Studies

BACKGROUND

Biodegradable subacromial balloon spacers (SBSs) have become increasingly used for the treatment of massive irreparable rotator cuff tears given their theorized clinical benefits; however, the relationship between biomechanical functions of the balloon spacer and clinical benefits remains unclear.

PURPOSE

To perform a systematic review and meta-analysis of controlled laboratory studies investigating the use of SBSs for massive irreparable rotator cuff tears.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

PubMed, OVID/Medline, and Cochrane databases were queried in July 2022 for biomechanical data pertaining to SBS implantation in cadaveric models of irreparable rotator cuff tears. Random-effects meta-analysis of continuous outcomes using the DerSimonian-Laird method was performed to estimate pooled-treatment effect sizes between the irreparable rotator cuff tear state and the state in which an SBS was implanted. Data reported variably or in formats not amenable to analysis were presented descriptively.

RESULTS

Five studies involving 44 cadaveric specimens were included. At 0° of shoulder abduction, SBS implantation resulted in a mean inferior humeral head translation of 4.80 mm (95% CI, 3.20-6.40; P < .001) relative to the irreparable rotator cuff tear state. This decreased to 4.39 mm and 4.35 mm at 30° and 60° of abduction, respectively. At 0° of abduction, implantation of an SBS was associated with a 5.01-mm (95% CI, 3.56-6.46, P < .001) anterior translation of the glenohumeral center of contact pressure relative to the irreparable tear state. This translation changed to 5.11 mm and 5.49 mm at 30° and 60° of abduction. In 2 studies, SBS implantation restored the glenohumeral contact pressure to that of the intact state and significantly reduced subacromial pressure distribution over a rotator cuff repair state. In 1 study, a high balloon fill volume (40 mL) resulted in a significant 10.3 ± 1.4-mm more anterior humeral head position relative to the intact cuff state.

CONCLUSION

SBS implantation in cadaveric models of irreparable rotator cuff tears results in significant improvements in humeral head position at 0°, 30°, and 60° of shoulder abduction. Balloon spacers may also improve glenohumeral and subacromial contact pressures, although insufficient evidence currently exists to corroborate these findings. High balloon fill volumes (40 mL) may confer supraphysiologic anteroinferior translation of the humeral head.

An in-vitro biomechanical assessment of humeral head migration following irreparable rotator cuff tear and subacromial balloon reconstruction

BACKGROUND

A resorbable subacromial balloon has been developed to address humeral head migration following posterosuperior rotator cuff tears. The purpose of this experimental assessment was to quantify the effect of balloon augmentation on humeral head position.

METHODS

Eight cadaveric shoulders were subjected to 0°, 30°, 60° and 90° of abduction via a shoulder simulator. The deltoid was activated at 40N, then 80N. The subscapularis and infraspinatus with teres minor were then applied independently and together to create four muscle activation states for each deltoid load. The shoulder was tested intact, torn, then with the balloon. The centre of the humeral head was tracked using active optical markers.

RESULTS

When the rotator cuff was torn, the humeral head translated superior by 1.4 ± 1 mm overall (P = 0.009). Following balloon augment, the humeral head translated inferiorly by 2 ± 2 mm relative to the intact state (P = 0.042), and significantly more anterior than the intact (3 ± 2 mm; P = 0.005) state. Rotator cuff variation was only significantly different when the balloon was used, with the subscapularis translating the humeral head posteriorly (P = 0.006).

DISCUSSION

The subacromial balloon inferiorized the humeral head compared to the torn state. Unexpected anterior humeral head translation was attributed to the posterosuperior balloon placement relative to the humeral head.

Outcomes of Subacromial Balloon Spacer Implantation for Massive and Irreparable Rotator Cuff Tears: A Systematic Review

Background

Selection of optimal treatment for massive to irreparable rotator cuff tears (RCTs) entails a challenging decision-making process in which surgeons must consider several factors, including duration of symptoms, tear pattern, tear size, and muscle quality, as well as patient characteristics such as age, comorbidities, shoulder dominance, and activity level. Unfortunately, no clear consensus has been reached regarding optimal management.

Purpose

To systematically review the published literature assessing outcomes after subacromial balloon spacer implantation for treatment of massive and irreparable RCTs.

Study Design

Systematic review; Level of evidence, 4.

Methods

A comprehensive literature search was performed in September 2018 through use of MEDLINE and the Cochrane Library electronic databases. Studies were assessed for multiple outcomes of interest including Constant score, Oxford Shoulder Score (OSS), University of California Los Angeles (UCLA) Shoulder Score, complications, and patient satisfaction.

Results

After applying the selection criteria, 12 clinical studies were included for data extraction and analysis. In total, 291 shoulders (in 284 patients) treated with subacromial balloon spacer implantation were pooled for evaluation, with a mean follow-up of 22.9 ± 14.9 months (range, 6-60 months). Constant scores were used as an outcome metric for 267 shoulders (91.7%; 11 studies), with improvements in mean Constant score ranging from 18.5 to 49.6 points. Patient satisfaction was assessed in 105 patients (37.0%; 5 studies), with rates of patients indicating they were satisfied or very satisfied with their treatment outcome ranging from 45.8% to 100%. A total of 6 patients (2.1%) experienced complications related to balloon spacer implantation, including transient neurapraxia of the lateral antebrachial cutaneous nerve, superficial wound infection, deep wound infection, and balloon migration. Of these, 3 patients (2 balloon migration, 1 deep wound infection) required subsequent surgeries for balloon removal.

Conclusion

Placement of the subacromial balloon spacer is a minimally invasive, technically simple procedure with favorable patient-reported outcomes at limited short-term follow-up. However, inherent methodological limitations and patient heterogeneity between studies may impair our ability to fully characterize the longer term efficacy, particularly relative to other potential surgical options. Further prospective randomized or comparative studies are warranted to ascertain clinical outcomes of subacromial balloon spacer in the management of massive and irreparable RCTs.

The effect of the subacromial balloon spacer on humeral head translation in the treatment of massive, irreparable rotator cuff tears: a biomechanical assessment

BACKGROUND

The current management of massive, irreparable rotator cuff tears is challenging, and no individual surgical technique has demonstrated clinical superiority. This study evaluated the role of a subacromial balloon spacer and its ability to depress the humeral head in the setting of a massive, irreparable rotator cuff tear.

METHODS

Eight cadaveric shoulders were tested. The specimens were mounted onto a shoulder simulator that applied muscle loading. Five shoulder states were tested: intact; irreparable rotator cuff tear; and inflation of the subacromial balloon spacer with 10, 25, and 40 mL of saline solution on the irreparable rotator cuff tear. Humeral head migration was measured at 0°, 30°, 60°, and 90° of shoulder abduction.

RESULTS

After creation of a massive, irreparable rotator cuff tear, in 0° of abduction, the humeral head migrated superiorly by a mean of 3.5 ± 0.7 mm compared with the intact shoulder state (P = .002). The subacromial balloon spacer inflated to 25 mL translated the humeral head inferiorly relative to the torn state by an average of 3.2 ± 0.6 mm (P = .001) for all abduction angles. The balloon inflated to 10 mL was ineffective at restoring humeral head position as it was still significantly superior than intact (P = .017). The balloon inflated to 40 mL was successful in depressing the humeral head; however, it over-translated the humeral head anteroinferiorly, such that it was significantly different from the intact condition (P < .001). Overall, the 25-mL balloon best restored the humeral head position.

CONCLUSION

The results of this study demonstrate that the subacromial balloon spacer is most effective in depressing the humeral head and restoring the glenohumeral joint position when inflated to 25 mL.