Knee pain Flashcards
Menisci : Anatomy
Menisci : medial and lateral meniscus. The rounded bones at the end of the femur
Miniscal tear : Clinical features
Trigger : Twisting movement
1. Tenderness along joint tlines of the knee
2. Pain worse on knee straightening
3. ‘Locking’ of knee - torn peice of meniscus may interfere with normal movement of joint
4. Swelling - slightly delayed than act
Miniscal tear : Investigation
- Mc Murray test
* Internal rotation + Pressure to inside of knee causes pain : Lateral meniscal damage
* External rotation of foot + Pressure to outside of knee causes pain : Medial meniscal damage - MRI
Miniscal tear : Management
1 . Arthroscopy* (keyhole surgery) of the knee joint. The main options are:
* Repair of the meniscus if possible
2 . Physiotherapy - can be used for rehabilitation after the initial pain and swelling have settled.
ACL + PCL : Anatomy
- The ACL attaches at the anterior intercondylar area on the tibia
- The PCL attaches at the posterior intercondylar area on the tibia
1 . The ACL stops the tibia from sliding forward in relation to the femur.
2 . The PCL tops the tibia sliding backwards in relation to the femur.
ACL : Clinical features
The ACL is typically damaged during a twisting injury to the knee. The injury causes:
* Pain
* Swelling - immediately
* “Pop” sound or sensation
Patients with ACL injuries will have instability of the knee joint. The tibia can move anteriorly below the femur } KEY FEATURE
ACL : Investigations
Anterior drawer test* can be used to assess for anterior cruciate ligament damage.
- The patient is lying flat with knee flexed with the foot flat on the couch.
- The examiner sits on the patient’s toes to stabilise the foot.
- The examiner holds the leg just below the knee and pulls the proximal tibia anteriorly, sliding it forward from the femur at the knee
- With ACL damage, the tibia can move an excessive distance anteriorly, and the examiner will not be able to feel a clear end-point to the movement
1 . MRI scan is usually the first-line imaging investigation for establishing the diagnosis.
2 . Arthroscopy can be used to visualise the cruciate ligament and is the gold-standard investigation for diagnosing a cruciate ligament tear.
ACL : Management
Arthroscopic surgery to reconstruct the ligament is often required, particularly in active and young patients.
PCL - anatomy and function
Anatomy
The PCL is situated within the knee joint, crossing from the posterior (back) aspect of the femur to the anterior (front) aspect of the tibia.
It is located just behind the ACL.
Function
It prevents excessive backward movement of the tibia in relation to the femur.
PCL : Mechanism of injury
- Excessive anterior force applied to the proximal tibia - resulting in excessive backwards bending of the knee.
- Due to car accident
PCL : Clinical features
- Pain and tenderness : over posterior joint line, on the back of the knee
- Knee swelling - delayed and not as prominent as ACL
- Instability of the knee joint
- Difficulty weight bearing
PCL - Examination
Positive Posterior Drawer Test:
The Posterior Drawer Test is a clinical examination maneuver used to assess the integrity of the PCL. A positive test result indicates increased posterior translation of the tibia relative to the femur.
Medial Collateral Ligament (MCL) Injury: Anatomy
Anatomy: The MCL is located on the inner side of the knee, connecting the femur to the tibia.
Medial Collateral Ligament (MCL) Injury: MOA
Valgus Force: MCL injuries often result from a valgus force, which is a force that pushes the knee inward, stressing the outer (lateral) side of the knee.
- Sudden twisiting movement
Medial Collateral Ligament (MCL) Injury: Clinical presentation
Pain and Tenderness: along the inner side of the knee.
Swelling: Swelling may develop, but it is typically less severe than in ACL injuries.
Instability: MCL injuries may cause a feeling of instability, especially during weight-bearing activities.
