Both isolated and multi-ligament posterior cruciate ligament reconstruction results in improved subjective outcome: results from the Danish Knee Ligament Reconstruction Registry

There are few descriptions of outcomes after posterior cruciate ligament (PCL) reconstruction in the literature due to the rarity of this type of knee injury. Since 2005, the Danish Knee Ligament Reconstruction Registry (DKRR) has monitored outcomes of PCL reconstructions. This study describes the epidemiology of PCL reconstruction and subsequent outcomes in a Danish population. Of 23,253 knee ligament reconstructions performed in 2005-2015, 581 were registered as PCL reconstructions in the DKRR. The types of reconstruction were classified as isolated (n = 237) or multi-ligament (n = 344), and the cause of injury and concomitant meniscus and cartilage injury data were extracted. The outcome at 1-year follow-up was based on the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Tegner activity level. The outcome data were compared with data on 21.820 primary anterior cruciate ligament (ACL) reconstructions. Isolated PCL reconstruction was performed in 43% of cases. Meniscus lesions and cartilage lesions were seen in 19 and 15% of cases, respectively. The main causes of PCL injuries were sports (43%) and traffic accidents (33%). The KOOS improved from pre-operative to 1-year follow-up for both isolated PCL reconstructions and multi-ligament PCL reconstructions but did not reach the levels of those recorded in ACL reconstructions. Multi-ligament reconstructions showed the highest improvement in KOOS. The Tegner activity levels for isolated and multi-ligament PCL reconstructions were 4 (0-7) and 4 (0-8), respectively. PCL reconstructions represented only 2.6% of all knee ligament reconstructions in Denmark. Sports and traffic accidents were the main causes of injury. Meniscus and cartilage injuries were less frequent in PCL injuries as compared to ACL injuries. Isolated PCL and multi-ligament PCL reconstructions showed significant improvements in subjective outcomes but did not reach those observed in ACL reconstructions. Patients should be counselled about expected outcomes after PCL reconstruction. III.