Paper 51: A Radiostereometric Analysis of Tendon Migration following Arthroscopic and Mini-Open Biceps Tenodesis: Interference Screw confers Greater Construct Stability than All-Suture Suture Anchor Fixation, with No Difference in Patient-Reported Outcomes

OBJECTIVES: To quantify the postoperative migration of the BT construct between arthroscopic suprapectoral (ASPBT) and open subpectoral (OSPBT) techniques via interference screw (IS) or all-suture anchor with a single suture (SSSA) fixation with radiostereometric analysis (RSA). METHODS: Distal migration of the biceps tendon following OSPBT with a Polyetheretherketone (PEEK) IS, OSPBT with one SSSA, ASPBT with PEEK IS, and ASPBT with two SSSAs was measured prospectively. Patients with symptomatic biceps tendinopathy and preoperative Patient-Reported Outcome Measures (PROMs) including CMS, SANE, or PROMIS-UE scores were included. A tantalum bead was sutured on the proximal end of the long head biceps tendon before fixation. AP radiographs were performed immediately postoperatively, 1 week, and 3 months. Bead migration was measured, and PROMs were compared. RESULTS: Of 115 patients, 94 were available for final follow-up (82%). Average age was 52.1±10.5 years, and BMI was 30.8±5.4 kg/m2. There was no difference in tendon migration between OSPBT and ASPBT performed with an IS (P=0.70). OSPBT performed with one SSSA (21.70 mm) demonstrated significantly greater migration than ASPBT with IS (4.31mm, P<0.001) and OSPBT with IS (5.04 mm, P<0.001). Three patients (9.4%) who had OSPBT with one SSSA and one who had ASPBT with two SSSAs (3.8%), developed a Popeye deformity; none occurred in the IS groups. Mean 12-week bead migration in patients with versus without Popeye deformity was 60.8 mm and 11.2 mm, respectively (P<0.0001). PROMs did not differ at final follow-up. CONCLUSIONS: ASPBT and OSPBT with IS fixation demonstrated the least tendon migration, while OSPBT with one SSSA yielded the most. Compared to IS, fixation with one, but not two, SSSAs resulted in significantly greater migration. Average bead migration following a Popeye deformity was 6.1cm. To minimize migration when using SSSAs, at least 2 sutures should be used with an interlocking pattern within the tendon.