Summary

This study compares two generations of arthroscopic anatomic glenoid reconstruction (AAGR) and finds that the second generation, using customized distal tibial allografts, significantly reduces hardware complications and the need for revision surgery.

Abstract

Purpose

Arthroscopic anatomic glenoid reconstruction (AAGR) is an emerging surgical technique for shoulder instability. AAGR has been shown to have excellent short and mid-term outcomes, with recurrence rates like a Latarjet and a safety profile similar to Bankart repair. One drawback of AAGR is the associated hardware complications over time as glenoid remodelling occurs. To reduce hardware irritation, an adapted AAGR technique has been developed, using a custom-sized distal tibial allograft (DTA) to recreate individual patients’ anatomy. The purpose of this study was to compare differences in the rate of hardware complications between two generations of the AAGR technique.

Methods

A retrospective review was performed of 144 patients who underwent AAGR surgery using DTA with screws. A Generation One (G1) group comprised of patients from 2014-2019 (n = 84) and a Generation Two (G2) group comprised of patients from 2020-2022 (n = 60). Charts were reviewed for age at surgery, gender, side of procedure, date of surgery, graft size, Western Ontario Shoulder Instability (WOSI) scores, and functional outcomes including strength and range of motion. Pre- and post-operative CT scans were collected for analysis of graft AP diameter, glenoid AP diameter, graft positioning, screw prominence, and resorption grade.

Results

Demographics were similar between groups. In the G2 group, 2.9% of patients experienced hardware complications compared to 10.7% in G1 (p=0.123). No G2 patients underwent revision hardware removal, while 8.3% of G1 patients required revision surgery for hardware removal (p=0.025). DTA graft sizes were larger in the G1 group (p=0.025), however the graft + glenoid AP diameter on 1-year post-operative CTs was similar between groups (p=0.400). Both groups saw significant improvement in WOSI scores, strength, and range of motion from pre- to post-operative.

Conclusion

All patients demonstrated excellent outcomes following AAGR. There was a lower rate of hardware complications in the G2 group, with no patients requiring revision surgery for hardware removal. Though patients in the G1 group were given larger DTA grafts at time of surgery, both groups demonstrated comparable graft + glenoid AP diameters following AAGR, suggesting that grafts remodel to the native glenoid anatomy. Use of an individualized DTA reduces graft resorption and subsequent screw protrusion, lowering the incidence of hardware complications.