Knee Pain Disorders
Anserine bursitis is common with osteoarthritis due to inflammation of the bursa located 5 cm inferior and anteromedial to the knee joint and is characterized by swelling and pin especially at night when the knees are placed on each other. The pain can be provoked by pressing on the bursa site. Treat with rest, NSAIDs, physiotherapy and steroid injection if needed.
Anterior cruciate ligament ACL tear happens when the knee is suddenly twisted while the foot is firmly planted to the ground. The knee will be swollen and painful with a positive anterior drawer sign (the tibia moves forward more than 5 mm when the knee is flexed and the tibia pulled forward). Treat pain and refer to orthopedics.
Chondromalacia Patellae presents with pain while climbing the stairs and can be elicited by pressing on the patella. Order MRI to diagnose. Treat with NSAIDs and quadriceps strengthening maneuvers. Refer to orthopedics if no improvement.
Iliotibial band syndrome characterized by knife-like pain on the lateral aspect of the thigh down to the knee elicited by standing with the knee flexed. Treat with NSAIDs, physiotherapy or steroid injections.
Lateral collateral ligament injury characterized by pain and tenderness on the lateral aspect of the knee that feels unstable like it is giving away. Elicit pain with the varus stress test where the clinician will apply pressure on the inside while the knee is flexed 20-30 degrees.
Lateral meniscal injury happens when the knee is suddenly twisted while the foot is firmly planted to the ground. Pain and tenderness on the lateral aspect of the joint margin on motion or touching. McMurray test is positive (bring the knee back from full flexion elicit pain). Diagnose with MRI. Treat with rest, NSAIDs, physiotherapy or orthopedics referral.
Medial collateral ligament injury characterized by pain and tenderness on the medial aspect of the knee that feels unstable like it is giving away. Elicit pain with the valgus stress test where the clinician will apply pressure on the outside while the knee is flexed 20-30 degrees.
Medial meniscal injury happens when the knee is suddenly twisted while the foot is firmly planted to the ground. Pain and tenderness on the medial aspect of the joint margin on motion or touching. McMurray test is positive (bring the knee back from full flexion elicit pain and clicking sensation). Diagnose with MRI. Treat with rest, NSAIDs, physiotherapy or orthopedics referral.
Patellofemoral pain syndrome (runner's or jumper's knee) is probably the most common cause of knee pain after osteoarthritis. Pain typically worsens on going down the stairs. Elicit the pain by pushing the patella against the femur. Treat with short coarse NSAIDs and quadriceps strengthening maneuvers.
Posterior cruciate ligament PCL tear happens when the knee is suddenly hyperextended. The knee will be swollen and painful with a positive posterior drawer sign (the tibia moves backward more than 5 mm when the knee is flexed and the tibia pushed backward). Treat pain and refer to orthopedics.
Prepatellar bursitis characterized by swelling and pain at the anterior knee that can happen due to trauma, infection or inflammation (e.g. gout). Diagnose by aspiration and culture. Treat with rest, NSAIDs and if indicated antibiotics.
Ruptured (popliteal) Baker cyst characterized by swelling at the popliteal fossa with pain that radiates down to the calf with bruising sometimes reaching to the inner side of the ankle. Diagnose with ultrasound and treat with leg elevation, rest, steroid injection and probably drainage if needed.
You can read more about the knee disorders using this book Practical office orthopedics.
This post covers the points you need to know for your board exams as well as for teaching residents on the daily rounds. Medical professionals can't use the information here to treat their patients nor people can use the information her to treat themselves. If you are having any medical issues, contact your local emergency services or your primary care provider. Please refer to your doctor for medical advice.