Summary

This review demonstrates that distal tibial osteochondral allograft (DTA) is an effective option for glenoid reconstruction in anterior shoulder instability, offering improved functional outcomes, high union rates, and favorable biomechanical properties with low complication and revision rates.

Abstract

Introduction

Reconstruction of glenoid bone in anterior shoulder instability can utilise autograft options, including Latarjet, iliac crest or distal clavicle, or allografts, such as lunate fossa of distal radius, radial head or distal tibia. The aim of this review was to assess the clinical, radiological and biomechanical outcomes of distal tibial osteochondral allograft for reconstruction of glenoid with bone loss.

Methods

This review was prospectively registered on PROSPERO (reference number 528243) and PRISMA guidelines were followed. MEDLINE, Embase and Pubmed databases were search in December 2023. Studies reporting any radiological, biomechanical, functional or clinical outcomes after the use of distal tibial osteochondral allograft were included. Appraisal of study methodology was performed using the Methodical index for non-randomised studies (MINORS) tool.

Results

12 studies met the inclusion criteria: eight were clinical studies (n=345) and four were biomechanical studies (n =68). The mean age was 32.8 years (18 – 88) and mean follow-up was 26 months (16 – 47). Combining all studies for DTA, subluxation was reported in sixteen patients (3.5%) whilst recurrent dislocations in two patients (0.4%). Functional outcomes were reported in four studies and all studies demonstrated a statistically significant improvement post operatively for patients who underwent DTA. DTA radiological outcomes demonstrated a mean union rate of 97.5% (range 91 to 100%), varying rate of resorption (6% to 83%) and improvement in anteroposterior glenoid measurement (mean of 32.26 mm). Overall complication rate was 4.4% (range 0 to 7.5%); the most common were hardware related (1.3%) and nerve injury (1.04%) with majority of revisions (2.3%) being for hardware failure (1.3%). Seven studies compared the results of DTA against either an alternative allograft or coracoid autograft and no significant difference in recurrence rate and functional outcomes between the DTA and other cohorts were demonstrated. Three biomechanical studies analysed radius of curvature (ROC) of DTA with mean of 24.5 ± 1.9 (range 17.5 to 27.5 mm). This was similar to the ROC measurements of the glenoid with mean of 26.1 ± 2.8 (range 22.5 to 30 mm), when compared to the ROC of other autografts and allografts such as inferior coracoid (24.0 ± 2.1 [20-27.5]), lateral coracoid (13.2 ± 1.9 [10-15]), distal radius (20.7 ± 2.1 [20-27.5]), radial head (17.6 ± 2.6 [15-20]) and iliac crest autograft (>35, P=< 0.05). One study reported that DTA (4.20cm2, 2.70 kg/cm2) successfully restored contact area and contact pressure when compared to an intact glenoid (4.87cm2, 2.63 kg/cm2) and these values were higher than after a Latarjet procedure (3.52cm2, 2.83 kg/cm2).

Conclusion

Patients undergoing bone block with DTA for ASI, have significantly better post-operative functional scores, high union rate with low complication and revision rates. DTA also has a good radius of curvature with better contact pressure and contact area making it an ideal allograft choice for glenoid.