Van de Kleut, J Shoulder Elbow Surg 2022 - Bony Increased-Offset Reverse Shoulder Arthroplasty vs. Metal Augments in Reverse Shoulder Arthroplasty: A Prospective, Randomized Clinical Trial with 2-Year Follow-Up - Article Summary

Bony Increased-Offset Reverse Shoulder Arthroplasty vs. Metal Augments in Reverse Shoulder Arthroplasty: A Prospective, Randomized Clinical Trial with 2-Year Follow-Up

Van de Kleut, Athwal, et al.·J Shoulder Elbow Surg·2022·36 citations·RCT

Background

Reverse shoulder arthroplasty (RSA) is rapidly being adopted as the standard procedure for a growing number of shoulder pathologies. Lateralization of the glenoid component is known to reduce the incidence of scapular notching and possibly improve postoperative range of motion. A number of methods are used for glenoid component lateralization, including bony increased-offset reverse shoulder arthroplasty (BIO-RSA) and porous metal-augmented baseplates. Presently, there exists little comparative literature on bone vs. metal lateralization. Therefore, the purpose of this study was to compare BIO-RSA to metal-augmented glenoid baseplates by assessing clinical outcomes and baseplate migration using model-based radiostereometric analysis.

Methods

A power analysis indicated 40 patients would be required for this radiostereometric study.
Therefore, 41 shoulders were prospectively randomized to receive either glenoid bone grafting (BIO-RSA) or a porous metal-augmented wedge-shaped titanium baseplate for primary reverse shoulder arthroplasty.
At the time of primary surgery, all patients also underwent implantation of 8 tantalum marker beads in the glenoid and coracoid.
Following surgery, participants were imaged using a calibrated, stereo radiographic technique.
Radiographs were acquired at 6 weeks (baseline), 3 months, 6 months, 1 year, and 2 years postoperatively.
Migration of the prosthesis was compared between bone and metal lateralization groups at each time point using a mixed effects model with Bonferroni test for multiple comparisons.
Outcome measures were acquired preoperatively and 2 years postoperatively.

Results

No significant differences were observed along any translation or rotation axis at any time point for either glenoid fixation group (P .175).
Mean total glenoid component translation ( standard deviation) 2 years postoperatively was 0.4 0.2 mm and 0.5 0.3 mm for BIO-RSA and metal-augmented baseplates, respectively (P = .784).
No significant differences were observed between groups in active range of motion; pain; American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score; Simple Shoulder Test score; Disabilities of the Arm, Shoulder, and Hand score; Constant Shoulder score; or Subjective Shoulder Value (P .117), with the exception of increased active external rotation in the BIO-RSA cohort (P = .036).

Conclusions

This randomized clinical trial assessed reverse shoulder arthroplasty glenoid component migration using model-based radiostereometric analysis. At 2-year follow-up, our results indicate both BIO-RSA and porous metal wedge augmented baseplates provide stable initial fixation, which is maintained at 2 years' follow-up, with no substantial differences in clinical outcomes.

Supplemental

Bony Increased-Offset Reverse Shoulder Arthroplasty vs. Metal Augments in Reverse Shoulder Arthroplasty: A Prospective, Randomized Clinical Trial with 2-Year Follow-Up

Van de Kleut, Athwal, et al.J Shoulder Elbow Surg202236 citationsRCT