JSES - 2026-08-01 - Journal Article
Effect of glenoid component compression timing on the cement-bone interface of pegged all-polyethylene glenoid components: a micro-computed tomography study.
Kendirci AŞ, Atasoy İT, Albayrak MO, Kabadaş FB, Okatar F, Erşen A
Topics
Key Takeaway
Brief-early compression (70 N for 2 minutes followed by undisturbed curing) produced 273 mm³ greater cement-bone interdigitation volume than intermittent compression and 1.5% lower cement porosity, outperforming intermittent compression on all significant interface metrics in an ovine glenoid model.
Summary Depth
Choose how much analysis to show on this article page.
Summary
This study asked whether compression timing during PMMA curing affects cement-bone interface quality in pegged all-polyethylene glenoid components. Fifteen ovine scapulae were randomized to continuous, brief-early, or intermittent 70 N axial compression and analyzed by micro-CT for interdigitation volume, porosity, contact area, and penetration depth. Brief-early and continuous compression both outperformed intermittent on interdigitation volume (MD +273 mm³ and +162 mm³ respectively, both p<0.05) and porosity, while brief-early versus continuous differences did not reach statistical significance.
Key Limitation
The ovine scapula model has trabecular bone geometry and density that differs from human osteoarthritic glenoid bone, limiting direct translational applicability to the patients most likely to receive these implants.
Original Abstract
BACKGROUND
Glenoid loosening remains a principal failure mode after anatomic total shoulder arthroplasty. Cement pressurization improves fixation; however, the optimal timing of axial compression during polymethylmethacrylate curing remains unknown. We hypothesized that brief-early compression, followed by undisturbed curing would yield a more favorable cement-bone morphology than continuous or intermittent compression.
METHODS
Fifteen ovine scapulae received three-pegged all-polyethylene glenoid components (Next Health Products, Ankara, Turkey) using standard-viscosity polymethylmethacrylate. Specimens were randomized to continuous compression (70 N for 10 min), brief-early compression (70 N for 2 min, then none), or intermittent compression (70 N; 2 min on, 1 min off, 3 min on, 1 min off, and 3 min on) groups (n = 5/group). An axial load was applied using a universal testing machine and custom seating jig; no off-axis or cyclic loading was introduced. High-resolution micro-computed tomography with blinded analysis quantified cement-bone interdigitation volume, cement porosity, cement-bone contact area, penetration depth, and peri-implant trabecular bone mineral density. Group comparisons used one-way or Welch analysis of variance, Holm-Bonferroni correction across the 4 prespecified interface outcomes, and Tukey or Games-Howell tests for pairwise comparisons. Bone mineral density was analyzed exploratorily.
RESULTS
Omnibus tests showed significant group effects for interdigitation volume (P = .002), cement porosity (P < .001), and cement-bone contact area (P = .017), whereas penetration depth did not differ between the groups (P = .475) despite these differences. Brief-early and continuous compression produced greater interdigitation than intermittent compression (brief-early vs. intermittent mean difference [MD] +273 mm 3 , 95% confidence interval [CI] 119-428; P = .001; continuous vs. intermittent MD +162 mm 3 , 95% CI 7-317; P = .040), whereas brief-early versus continuous compression was not significant (P = .176). For cement porosity, intermittent compression yielded more porous mantles than brief-early (MD +1.5%, 95% CI 0.9-2.2; P < .001) and continuous (MD +0.9%, 95% CI 0.3-1.6; P = .006); continuous versus brief-early was not significant (P = .091). Cement-bone contact area was greatest with brief-early and lowest with intermittent; only the brief-early versus intermittent comparison reached significance (MD +20 mm 2 , 95% CI 8-32; P = .004).
CONCLUSION
In this ovine glenoid model, brief-early compression followed by undisturbed curing produced a more favorable cement-bone micro-architecture than an intermittent pattern and a numerically more favorable profile than continuous compression without altering penetration depth; however, the brief-early versus continuous comparison did not reach statistical significance. These micro-computed tomography findings support brief-early compression for pegged all-polyethylene glenoids, but remain hypothesis-generating pending mechanical validation.