Ultrahigh-molecular-weight polyethylene implant improves biomechanical properties for patellar ligament repair in dogs: an ex vivo randomized study.

Objective: To assess the biomechanical properties and failure mode of 3 different repair methods in simulated midsubstance canine patella ligament rupture on cadavers.

Methods: The sample was paired hindlimbs of 9 adult mixed-breed dogs. The study design was an experimental study on cadavers. Patellar ligaments were transected and sutured using a Bunnell and simple interrupted epitendinous pattern. They were then randomly reinforced with 1 of 3 techniques: a circumpatellar suture loop anchored distally to the tibial tuberosity (group 1), the same loop combined with a fascia lata strip (group 2), or a polyethylene synthetic implant sutured over the patella proximally and secured distally with an interference screw (group 3). Yield, peak, and failure load, stiffness, and mode of failure were evaluated.

Results: Six hindlimbs were assigned to each group. Augmentation with the synthetic implant (group 3) showed significantly greater yield, peak, and failure load than group 1. There were no significant differences between group 2 and either group 1 or group 3.

Conclusions: Patellar ligament repair augmented with a synthetic ultrahigh-molecular-weight polyethylene implant offered greater tensile strength than a Bunnell suture with an adjunction of a circumpatellar repair.

Clinical relevance: The use of a synthetic ultrahigh-molecular-weight polyethylene implant may offer a viable surgical option for patellar ligament repair. Further studies are warranted to assess the long-term outcome in vivo in patients with injured patellar ligament.