No abstract

Purpose In anterior cruciate ligament reconstruction with looped soft‐tissue grafts, an interference screw is frequently used for tibial fixation. This study compared three alternatives thought to improve the initial mechanical properties of direct bioabsorbable interference screw fixation: suturing the graft to close the loop, adding a supplementary staple, or increasing the oversize of the screw diameter relative to the bone tunnel from 1 to 2 mm. Methods Twenty‐eight porcine tibiae and porcine flexor digitorum profundus tendons were randomized into four testing groups: a base fixation using 10‐mm‐diameter screw with open‐looped graft, base fixation supplemented by an extracortical staple, base fixation but closing the looped graft by suturing its ends, and base fixation but using an 11‐mm screw. Graft and bone tunnel diameters were 9 mm in all specimens. Constructs were subjected to cyclic tensile load and finally pulled to failure to determine their structural properties. Results The main mode of failure in all groups was pull‐out of tendon strands after slippage past the screw. The sutured graft group displayed significantly lower residual displacement (mean value reduction: 47–67 %) and higher yield load (mean value increase: 38–54 %) than any alternative tested. No other statistical differences were found. Conclusions Suturing a soft‐tissue graft to form a closed loop enhanced the initial mechanical properties of tibial fixation with a bioabsorbable interference screw in anterior cruciate ligament reconstructions using a porcine model, and thus, this may be an efficient means to help in reducing post‐operative laxity and early clinical failure. No mechanical improvement was observed for an open‐looped tendon graft by adding an extracortical staple to supplement the screw fixation or by increasing the oversize of the screw to tunnel diameter from 1 to 2 mm.

In a porcine model of a repaired posterior meniscal root subjected to cyclic loads representative of current rehabilitation protocols in the early post-operative period under restricted loading conditions, suture cutout was not found as a main source of permanent root displacement when using suture thread or tape. Suture cutout progression started at high loading levels close to the ultimate load of the construct. Tape, with a meniscus-suture contact area larger than thread, produced higher ultimate load.

Treatment of posterior meniscal roots tears evolved after biomechanical evidence of increased pressures on the tibiofemoral cartilage produced by this lesion and the subsequent accelerated development of arthritis or osteonecrosis observed clinically. However, little is known about the consequences of the detachment of the anterior roots. This in-vitro study analyzes the biomechanical changes in the tibiofemoral joint caused by avulsion of the anterior root of the lateral meniscus. The effectiveness of surgical root re-insertion to restore the pre-injured conditions is also evaluated. Using cadaveric knees at flexion angles from 0° to 90°, results show that the lesion significantly reduces the contact area and raises the pressure on the tibiofemoral cartilage of the injured compartment at all angles. Said modifications become larger at low flexion angles, which are the most frequent positions adopted by the knee in daily and sports activities, where they result similar to total meniscectomy. In-situ repair partially restores the contact biomechanics. Consequently, careful attention should be paid to proper diagnosis and treatment of detached anterior roots since the observed altered knee contact might induce similar degenerative problems in the cartilage as with completely detached posterior roots.

The purpose of this study was to compare, in an in vitro porcine model, the initial biomechanical properties of transtibial root repairs using two different methods to fix the sutures: knotting them over a suture button (SB) or with a knotless anchor (KA) that allows post-insertion tensioning attached to the anterior tibial cortex. The study hypothesis was that the KA method provides lower displacements and higher resistance than the SB method.