Tensioning Ligament and Tendon Repairs to Bone Using a Modified Screw-post Technique.

Purpose: The purpose of this study was to demonstrate how to tension tendon and ligament repairs or reconstructions to bone by using an oblique screw-post. A controlled experiment simulating this repair technique is reported, followed by 5 case examples.

Methods: A wood frame model was used to test 5 initial exposed screw lengths (4, 8, 12, 16, 20 mm) and 5 screw angles [90 (perpendicular to wood plane), 75, 60, 45, 30 degrees]. A spring-based force gauge was tied to the exposed 3.5 mm cortical screw with a washer using a #2 nonabsorbable braided suture, and the screw was fully advanced. System lengths were measured before and after advancement using digital calipers. Screw angles were measured with a protractor. Analysis of variance with post hoc paired t tests was performed to compare changes in system length with different initial exposed screw length and screw angle.

Results: Greater changes in system length was achieved with decreasing screw angle and increasing initial exposed length (P<0.05). A maximum change in system length of 12.4 mm (SD=0.4 mm) was achieved with a 45-degree screw with 20 mm initial exposed length (P<0.05). Five case examples where a screw-post was used to repair tendons and ligaments in the upper extremity are described.

Conclusions: An oblique screw-post can advance a tendon or ligament repair to bone. This can result in increased tension of the repaired structure, potentially providing a better repair or greater joint stability.