ANTERIOR KNEE PAIN
Pain at the front (anterior) of the knee
The most likely structures anteriorly are the knee cap (patella), ligaments, tendons, bones, fat pad and bursae. Anterior knee pain (AKP) is commonly a problem following a dislocation, fracture or associated injury to the knee cap which may be the result of recreational activities including running, cycling, skiing, football, basketball, netball, squash etc. Knee pain has been linked to obesity, having flexible joints and is more common in teenagers and young adults, more often girls. Short tight muscles or muscular weakness may also cause or refer pain to the knee plus, spinal conditions e.g. ‘sciatica’ can refer pain to the joint.
Patellofemoral pain syndrome (PFPS) (kneecap thigh bone problem!)
Common condition felt when bending and straightening the knee as the knee cap (patella) tracks up and down through the femoral groove at the end of the thigh bone. Pain occurs if the knee cap does not track smoothly often described as ’patella maltracking’. Likely causes are muscular or ligament strain and swelling through sporting overuse or injury.
Chondromalacia
A condition where the smooth cartilage on the back of the knee cap softens and breaks down causing pain which is most commonly seen in teenage girls.
Osgood-Schlatter disease & Sinding-Larsen-Johansson disease
Pain and tenderness +/- ‘lump’ below the knee joint where the patella tendon from the knee cap inserts into the shin bone. Commonly a condition seen in teenagers who participate in lots of sport.
Patella dislocation/subluxation
Uncommon condition where a sharp sudden pain causes the knee to give way linked to the knee cap slipping as it tracks through the groove in the femur (maltracking). The knee cap can dislocate to the outside of the knee and may require ED/Paramedics to relocate. Can smart a little! Girls more likely to experience than boys often linked to knock knees posture.
Patella tendinopathy
Pain within the tendon that connects the bottom of the kneecap to the shin bone. The tendon transmits forces generated in the quadriceps (thigh) muscles to the shin bone in order to straighten the leg or control bending of the leg. Following a period of relative inactivity or a sharp increase in activity the tendon can become irritable causing pain and discomfort. The rapid change in activity does not allow the tendon time to adapt and therefore the tendon is unable to tolerate the tension or loads being placed upon it resulting in pain. Sometimes referred to as ‘jumpers knee’ it can be treated successfully with physiotherapy and committed rehabilitation.
Quadriceps tendinopathy
Similar to patellar tendinopathy however occurs where the quadriceps (thigh) muscles attach to the top of the knee cap. Less common however the process remains the same and yes, we are amazing at treating also.
Anterior cruciate ligament injury (ACL)
You will know when you have injured this ligament as it occurs during sudden rotation of the knee such as direction change in tennis or football and commonly skiing also. If you stay away from sport you are unlikely to have a problem. One of the main ligaments within the knee joint its purpose is to provide stability between the thigh and shin bone. Complete rupture may require surgical repair, a stretched ACL will not require surgery, in both cases dedicated prolonged rehabilitation is required to regain stability, strength and to be able to consider a return to sporting activities.
Osteoarthritis (OA)
Osteoarthritis commonly affects the knees. A healthy joint is made up of two bones whose ends are covered in a shiny smooth coating of cartilage which in part allows the joint to slide, glide and rotate, providing functional movement. The cartilage within each joint is bathed in synovial fluid which nourishes the cartilage, maintaining good health and further providing shock absorption.
Over time our knee joints, essentially our cartilage, become worn like the tread on a tyre following years of bending, straightening and bearing weight. Our bodies attempt to repair the cartilage however are unable to replace cartilage tissue like-for-like with the shiny smooth cartilage slowly being replaced with rough bone. The change in joint structure causes symptoms of stiffness, swelling and pain that is known as osteoarthritis. Most common in the over 50’s.
Infrapatellar fat pad syndrome (Below the knee cap fat pad pain!)
A protective fat pad that is present in all knees becomes inflamed due to being nipped between the patellar and thigh bone. Most often caused through repetitive straightening of the leg or standing for long periods.
Bursitis
Bursae are small fluid filled cushions that serve to reduce compressive friction caused by muscles, tendons and ligaments as they pass over bone. When repetitive friction occurs the bursae become inflamed causing bursitis which can be painful. Can be considered an overuse injury, possibly due to increasing sporting hobbies and also associated with rheumatoid arthritis and gout.