When you are active in sport, you have to get used to the knocks and bumps, particularly in contact sports such as rugby and football. The knee is one of the most commonly injured joints of the body and although thankfully serious injury is rare, it is often difficult to know whether or not the injury you have sustained is serious and indeed when you should approach a specialist for an opinion.
The first pointer towards the severity of injury is what actually happens on the pitch. Most people are keen to continue to play on and an inability to complete the sporting activity may point to more than a simple ‘knock’. Any deformity of the knee or leg or significant immediate swelling should raise concerns and may warrant urgent attention. The best initial first aid is to immobilize the knee with a splint or brace, keep the weight off the leg and to seek early attention. In many cases this will involve a visit to accident and emergency department. It is important to remember that is often difficult to assess the knee fully immediately after an injury. It is important to recognise that In most cases of knee ligament or cartilage injury the first x-rays that are taken are normal.
If there is no evidence of a fracture on the x-ray you will commonly be discharged or possibly be advised to return for an orthopaedic clinic appointment. The key injuries which need to be picked up at this stage are, serious ligament injuries, injuries to the articular (joint surface) cartilage or the mensical cartilages of the knee. If there is significant swelling at that stage, then it often advisable to obtain and MRI scan which will show in detail the ‘soft tissues’ of the knee which are not revealed by an ordinary x-ray. In many cases the knee will settle over a few weeks, however if your knee continues to cause symptoms then further assessment may be required. The key indicators of a significant knee injury are persistent swelling, mechanical symptoms such as being unable to straighten the knee, grinding or crunching sensations within the knee or if the knee feels unstable or feels as if it is coming out of joint. In these cases further specialist opinion is advisable.
Mensical Cartilage Injuries
The menisci or meniscal cartilages are crescent shaped washers within the knee which help cushion the forces transmitted from the thigh bone (femur) to the shin bone (tibia), tearing of these cartilages may result in intermittent swelling of the knee, feelings of instability or mechanical symptoms of catching or locking. Damage to these cartilages can have a long term affect on the knee as increased pressures within the knee may lead to early arthritis if early treatment is not instituted.
Articular Cartilage Injuries
The articular cartilage is the shiny material on the end of the bone surfaces. It's role is to allow the joint to move smoothly. Damage to areas of cartilage can likewise result in swelling, mechanical symptoms or sensations of something catching within the knee. Occasionally in acute injuries pieces of cartilage with attached bone may become detached and become loose within the knee. It is sometimes possible to reattach these loose fragments. This needs to be performed as soon as possible after the injury to give these fragments the best chance of healing.
Knee Ligament Injuries
Although knee ligament injuries produce a lot of headlines in the media, due to their effects on professional athlete’s careers, they are thankfully fairly rare. Common injuries include sprains to the medial and lateral collateral ligaments (the ligaments on the inside and the outside of the knee). If these ligaments are not completely ruptured then they generally heal over a period of six to eight weeks, although in some cases healing may be more prolonged. More seriously for the sportsman are injuries to the anterior and posterior cruciate ligaments (ACL or PCL). Posterior cruciate ligament injuries often do not give any immediate functional problems but in the long term may result in abnormal loading patterns within the knee and the development of early arthritis. Anterior cruciate ligament (ACL) injuries tend to have a more dramatic effect on people’s ability to play sport. The anterior cruciate ligament is important in providing stability of the knee when performing twisting and turning activities. If your knee feels as if it is recurrently unstable and coming out of joint then this type of injury may well have occurred. If an anterior cruciate ligament injury is present then an early consultation with a specialist is advisable. Surgery is not required in all cases but it is important to discuss all treatment options to help prevent recurrent instability and reduce the risk of long term damage to the knee, in particular to the joint surfaces and meniscal cartilages.