Safety of the application of Rigidfix cross-pin system via different tibial tunnels for tibial fixation during anterior cruciate ligament reconstruction.
BACKGROUND
We investigate the safety of the application of the Rigidfix cross-pin system via different tibial tunnels in the tibial fixation during anterior cruciate ligament (ACL) reconstruction.


METHODS
Five adult fresh cadaver knees were fixed with the Rigidfix cross-pins in the tibial fixation site during ACL reconstruction. Two different tibial tunnel groups were established: in group A, the tunnel external aperture was placed at the 25° angle of coronal section; in group B, the tunnel external aperture was placed at the 45° angle of coronal section. The guide was placed at the plane 0.5 mm below articular facet through the tibial tunnel, with three rotation positions set at 0°, 30°, and 60° slopes. The incidences of iatrogenic injuries at tibial plateau cartilage (TPC), medial collateral ligament (MCL), and patellar tendon in three different slope angles were calculated in groups A and B and the results were analyzed by using chi square test.


RESULTS
The iatrogenic injuries at MCL, TPC, and patellar tendon could occur after the Rigidfix cross-pin system was placed 5 mm below tibial plateau cartilage for ACL reconstruction. The incidences of TPC injury (χ2 = 5.662, P = 0.017) and MCL injury (P = 0.048, Fisher exact probability method) were significantly lower in group A than in group B. However, the incidence of patellar tendon injury showed no significant difference between these two groups (χ2 = 0.120, P = 0.729).


CONCLUSIONS
When the Rigidfix cross-pin system is used for ACL reconstruction at the tibial fixation site, the external aperture of tibial tunnel should not be placed at the excessively posterosuperior site, to avoid MCL and TPC injuries.
['Wang|Jian|J|', 'Fan|Hua-Qiang|HQ|', 'Dai|Wenli|W|', 'Li|Hong-Da|HD|', 'Fu|Yang-Pan|YP|', 'Liu|Zhenhuang|Z|', 'Huang|Chang-Ming|CM|', 'Shi|Zhanjun|Z|']
D000328:Adult D016118:Anterior Cruciate Ligament D000070598:Anterior Cruciate Ligament Injuries D059549:Anterior Cruciate Ligament Reconstruction D001858:Bone Nails D002102:Cadaver D006801:Humans D007719:Knee Joint D013977:Tibia
Rigidfix Anterior cruciate ligament Iatrogenic injury Bone tunnel Tibia