Objectives

Osteochondral injuries, if not treated adequately, often lead to severe osteoarthritis. Possible treatment options include refixation of the fragment or replacement therapies such as Pridie drilling, microfracture or osteochondral grafts, all of which have certain disadvantages. Only refixation of the fragment can produce a smooth and resilient joint surface. The aim of this study was the evaluation of an ultrasound-activated bioresorbable pin for the refixation of osteochondral fragments under physiological conditions.

Aims: To clarify whether joint loading after meniscus repair causes increased pressure on the femoral condyle and is responsible for early cartilage damage. Methods: In sixteen human cadaver knees a bucket handle tear was created at the posterior horn of the medial and lateral meniscus. The lesion was repaired using two biodegradable implants (either Stingerª, Arrow¨, Dartª or Meniscal Screwª) on each occasion. Loading was compared to intact menisci and menisci after suture repair using 2/0 Ethibond. The specimens were mounted into specially designed jigs, taking all degree of freedom of the knee joint into account, and þxed to a material testing machine (Bionix 858 MTS). Constant loading of 350 N was performed during knee motion of 0¡Ð90¡ of ßexion. The meniscofemoral pressure was measured using the Tekscansystem. All þxation techniques were tested þve times. Results: Increased joint loading at the posterior horn occurred with increased ßexion angle of 0¡, 30¡, 60¡ and 90¡ of knee ßexion in the medial and lateral compartment (p< 0.05). No signiþcant increase in joint loading was noticed after meniscus repair with biodegradable implants. Conclusions: Biodegradable implants do not cause higher meniscofemoral joint loading due to meniscus implants in the posterior horn and resulting cartilage damage at the femoral condyle is unlikely.