Knee Ligament Injuries
Your knee joint is formed by three bones; femur (thighbone), tibia (shinbone) and patella (kneecap). Articular cartilage covers the ends of your femur and tibia as well as the back of your patella allowing the bones to glide smoothly. Bones are connected to other bones by ligaments. The four primary ligaments of your knee are the anterior cruciate (ACL), posterior cruciate (PCL), medial collateral (MCL) and lateral collateral ligament (PCL). The medial and lateral meniscus sit inside the joint and act as shock absorbers cushioning and stabilising the knee. Tendons connect muscles to bones. Any of these structures may be injured.
Knee Ligament Injuries
Cruciate Ligaments are inside the knee joint. The anterior and posterior ligaments cross each other and control the forward and backward movement of your knee. The ACL is most commonly injured by twisting on a stationary foot. ACL injuries often involve damage to other knee structures. A direct blow to a bent knee is often the mechanism for PCL injury.
Collateral ligaments are on the sides of your knee. The lateral collateral ligament is on the outside and the medial collateral ligament is on the inside of your knee. They control side to side movement of your knee. The medial collateral is injured more frequently than the lateral collateral ligament. Collateral ligaments are commonly caused by a blow to the inside (LCL injury) or outside (MCL injury) of the knee.
Injured ligaments are called sprains and are graded from 1-3 (mild-severe). It is possible to injure more than one ligament at the same time. A grade 1 sprain involves mild stretching of the ligament and mild pain with or without swelling. If untreated it can increase the risk of reinjury. Grade 2 sprains are referred to as partial tears they will swell and may bruise. Grade three sprains involve a complete rupture of the ligament and are associated with knee instability and difficulty weight bearing. Grade three injuries are often not painful as the pain fibres are torn at the time of injury.
Symptoms of Ligament Injuries
The symptoms of knee ligament sprains vary depending on which ligament(s) are damaged and the severity of the injury. Symptoms may include;
Loss of full range of movement
Instability or feeling of the knee giving way
Popping sound at time of injury
Self-care for ligament injuries
Suggestions for managing sprains until you can receive medical attention include;
RICE: rest, ice, compression, elevation
No HARM: no heat, no alcohol, no running (or other exercise), and no massage
Anti-inflammatory or pain relief medication if needed
Types of Treatment for Ligament Injuries
Sprains require medical attention. Different treatment options include;
X-rays and/or MRI’s may be required
Physiotherapy for Ligament Injuries;
- Grade one sprains usually heal with-in a few weeks however it takes six weeks for the collagen fibres to mature and the ligament to reach maximum strength. Initial physiotherapy will involve activity modification, avoiding painful activities, ice and soft tissue releases. Further physiotherapy will focus on strength and stability to prevent future injuries.
- Grade two sprains take up to six weeks to heal sufficiently for a return to activity. Initial physiotherapy will involve activity modification, avoiding painful activities, ice and soft tissue releases. A brace or taping may also be used to avoid stretching and stressing the healing ligament. Further physiotherapy will involve strengthening of lower limb muscles, proprioceptive training and individualised return to sport/activity training.
- Grade three sprains will take up to 12-16 weeks to heal sufficiently for a return to activity. Depending on the specific injury grade three sprains may be managed with physiotherapy alone, physiotherapy ‘prehab’ and then surgery, or with immediate surgery. Conservative physiotherapy management will involve the use of a brace to protect the knee and will initially focus on activity modification, avoiding painful activities, ice and soft tissue releases. Further physiotherapy will involve strengthening of lower limb muscles, proprioceptive training and a gradual return to sport/activity training.
Surgery for Ligament Injuries
Multi-ligament injuries as well as ACL ruptures are treated surgically in most patient groups. In an ACL repair the ligament is replaced by a graft which may be from the; patellar tendon, hamstring tendon, quadriceps tendon, a lars ligament or an allograft from a cadaver. Physiotherapy is always required after a ligament reconstruction.