April 14, 2020
The ligaments are bands of fibrous tissue that connect bone to bone. The main ligaments of the knee are the lateral & medial collateral ligaments (LCL & MCL), the posterior cruciate (PCL), and the anterior cruciate ligament (ACL). Knee ligament injuries are common across all sports with 15% of elite athletes injuring the ACL in any given year. Female athletes are 2-8 times more likely to injure the ACL than their male counterparts. With minimal statistical differences in incidence of ligament damage based on players’ positions, knee ligament injuries account for 10% of all rugby injuries making them the second most common injury in the sport.
MCL injuries are most common among pro rugby athletes according to the world rugby surveillance study, amounting to 53% of total knee ligament injuries. MCL incidence is followed by ACL injuries accounting for 29% of professional rugby injuries. MCL injuries typically occur due to side tackles where the knee is forced into a knock-kneed position, resulting in excessive stress being placed on the inside of the knee. 57% of ACL injuries are contact injuries that occur either during offensive running or by being tackled. Non-contact ACL injuries occur during side-stepping, compromising the knee’s stability.
Knee ligament injury is by far the most severe rugby injury from a time loss perspective. The time loss due to knee ligament injuries increased by 32% between 2011 and 2015’s rugby world cups. 30% of time loss is attributed to knee ligament injuries and the average time it took athletes to return to play was 88 days. Avoiding under estimation of the rehab period, this number is an average of all grades of tears to all ligaments. The typical period following surgical correction of ACL rupture is 12 months of physiotherapy led, goal-focussed rehabilitation.
Like any injury, once an ACL ruptures once, an athlete is susceptible to a second tear with recurrence rates varying from 1-11% in the research, meaning rehab programmes should culminate in a continuous injury prevention program.