The knee is, on the surface, a simple hinge joint. But when you get into the anatomy of the knee, it gets much more complicated. The lateral and medical menisci, the multiple ligaments and tendons, not to mention the bones themselves, can all lead to different types of issues due to trauma or bad biomechanics.
So what are some of the diagnosies that can lead to knee pain?
ACL Sprain/Tear
The ACL is the anterior cruciate ligament, and is the main ligament that stops the tibia from sliding forward. Injuries can occur after repetitive micro-trauma, or a single traumatic event like a hit to the knee or a sudden foot plant and turn. It is commen in females, especially girls who participate in athletics like soccer. There may be a pop at time of injury, swelling and a feeling of instability. Surgery can be needed, however conservative care can also help many patiets.
PCL Tear/Sprain
Similar to the ACL above, the Posterior cruciate ligament has the opposing effect. It is actually stronger than the ACL, and has more blood supply, which could be why injury is less likely/severe. Again, these tears and sprains tend to me sport related, and include falling on a flexed knee as a method of injury. Conservative care can definitely be an option depending on the severity of the injury, with surgery being an option for complete tears and serious injury.
MCL and LCL Sprain
The medial and lateral collateral ligament provide side to side stability of the knee. These can also lead to meniscus injuries, as we talk about next. When a lateral force is applied to the knee, the ligament on the opposite side tends to be damaged. This is treated like most other sprain/strains of the body with conservative care, including massage, physio and acupuncture.
Meniscus Tear
The meniscus is a cartilaginous disc between your femur and tibia, it helps cushion the joint and carry load. Injury of the meniscus (we have a lateral and a medial) can occur from twisting of the knee, and osteoarthritis can also be a precursor to damage. Pain is typically along the joint line, can there can be locking, catching and clicking in the knee. MRI is the gold standard of diagnosis, but a good therapist can get a good idea from history and testing. Below are the different types of tears you cans see. Surgery can be indicated in severe cases, but an attempt at conservative care is typically tried first.
*Image from OrthoInfo*
Chondromalacia Patella
This is an abnormal sofenting and degeneration of cartage on the back side of the patella (knee cap). It is typically caused by a misalignment and tracking issue as the patella moves. Pain is usually local to that area, and can be caused from trauma, stress or aging. Conservative care and working to correct the biomechanics of the knee is key for this diagnosis, with surgery rarely being needed.
Jumper’s Knee
AKA Patellar tendiopathy, this is an inflammation of the tendon of the quadriceps or infrapatellar tendon. Repetitive stress is usually the cause of this, including jumping and running movements. There is usually pain under the knee cap this is achey, and activity makes it worse. As this tends to be a stress/biomechanical issue, conservative care is the go to for this. Addressing muscles, joints and ligaments and correcting bad patterns can help with pain.
ITB
This stands for the illiotibial band, and this tendon can get inflamed and become a tendinopathy. It typically manifest on the outside of the knee, where the tendon rubs against the femur. This is usually a friction injury, cause by overuse and possible bad mechanics. Working on the hips as well as the knees can aid in this diagnosis, as well as training proper mechanics with activities.
Knee Bursitis
This is inflammation of the bursa (a sac that is usually flat that helps with friction) around the knee, and usually pairs up with another knee issue. The 4 most common bursa for this to occur are the IT band bursa, the pec anserine bursa, the gastrocnemius bursa (aka Baker's cyst), and the prepaterllar bursa (housemaid's knee). These bursa can irritate, swell and get inflamed, causing pain and sometimes restriction in movement depending on location. These can be drained or removed surgically, but that is usually the last resort, with corrective care, massage, acupuncture and others being good options.
Osgood Schlatter’s
This occurs when the bone and cartilage degenerates, causing fragments (or joint mice) to float in the joint space. This happens after trauma to the bone and a lack of blood supply. A vague knee pain usually presents, and can look similar to a meniscus tear. MRI and CT can be helpful in these cases, with a surgery being recommended if typical care fails after 3 months or so.
Pain in the knee can be many things, and getting a proper diagnosis is important to ensure that you get the care you need and recover as best you can!