AOSSM/AANA Specialty Day 2020-Radiostereometric Analysis of Biceps Tenodesis

Radiostereometric Analysis of Biceps Tenodesis_ A Comparison of Techniques

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This prospective comparative cohort study by Forsythe et al. evaluates construct stability and tendon lengthening after biceps tenodesis using radiostereometric analysis (RSA) with tantalum bead markers. Four fixation techniques were compared: open subpectoral interference screw, arthroscopic suprapectoral interference screw, open subpectoral single all-suture anchor (ASSA), and arthroscopic suprapectoral double ASSA. The study included patients aged 18-65 undergoing biceps tenodesis for symptomatic tendinopathy.<br /><br />Tantalum beads were placed in the biceps tendon to measure migration intraoperatively, at 1 week and 12 weeks postoperatively as a marker of tendon elongation/remodeling. Clinical failure was defined as bead migration ≥3 cm or presence of Popeye deformity.<br /><br />Key findings include:<br />- Open interference screw fixation demonstrated significantly less bead migration compared to open subpectoral single ASSA at both 1 week (0.1 mm vs. 4.6 mm, p<0.001) and 3 months (3.4 mm vs. 15.8 mm, p=0.014).<br />- Arthroscopic suprapectoral double ASSA showed less migration than open single ASSA approaching significance at 3 months (p=0.055).<br />- When pooled, interference screw techniques (open and arthroscopic) showed significantly less migration than ASSA techniques (p<0.05).<br />- No significant differences were found between open and arthroscopic interference screw fixation, or between arthroscopic interference screw and double ASSA groups.<br /><br />Biomechanically, interference screws have higher load to failure and stiffness compared to single suture anchors, while double anchors approximate interference screw strength. Tendon remodeling involves initial hyperemia and fibroplasia, followed by increased tissue density and collagen fiber alignment.<br /><br />In conclusion, interference screw fixation provides greater construct stability with less tendon migration than all-suture anchor techniques after biceps tenodesis, regardless of approach (open vs. arthroscopic). Tendon elongation occurs but does not appear to impact clinical outcomes or depend on tenodesis location. The study emphasizes the clinical relevance of fixation method on tendon stability during healing. Further work will clarify the biological remodeling process underlying tendon elongation.

Keywords

biceps tenodesis

interference screw fixation

all-suture anchor (ASSA)

tendon migration

radiostereometric analysis (RSA)

tantalum bead markers

construct stability

tendon elongation

arthroscopic vs open technique

clinical outcomes