Knee pain can be caused by injuries, mechanical problems, types of arthritis and other problems.
ACL injury. Overstretching or tearing of the anterior cruciate ligament. The primary sign of an ACL injury is a popping noise.
Fractures. The bones of the knee, including the kneecap (patella), can be broken during motor vehicle collisions or falls.
Meniscal tear. The meniscus is a C-shaped piece of tough, rubbery cartilage that acts as a shock absorber between your shinbone and thighbone. It can be torn if you suddenly twist your knee while bearing weight on it. Meniscal tears present as severe pain, swelling, and possibly catching, clicking, difficulty on deep knee bending and locking of the knee in partial flexion.
The typical meniscal pain profile comprises well localised joint-line pain (with medial pain generally being indicative of a medial tear and vice-versa). Meniscal pain occurs during torsional, weight bearing knee movements (classically pivoting on the knee while walking) as a sharp stab lasting several seconds, often followed by a dull ache for several hours. Pain may wake the patient from sleep as the tender medial aspect of the knee strikes the other side as the patient rolls over in bed. There is no resting pain.
Ax: McMurray, Apley (grinding), Thessaly
Knee bursopathy. A bursa is a closed sac filled with synovial fluid. The knee has 11 bursae whose principal function is to reduce friction between two tissues, such as tendons, ligaments, and bone. The location of bursae in the knee can be divided into 3 regions: anterior, medial, lateral, and posterior. The most common patient complaints in knee bursopathies are local knee pain, swelling, and tenderness in the area of the affected bursa. Diagnosis of pes anserine bursopathy should be considered when there is spontaneous pain inferomedial to the knee joint. The symptoms may or may not be associated with range of motion (ROM) limitation and/or antalgic gait. A complete knee examination including inspection, palpation, ROM, ligament stability, knee special tests, and neurologic examination should be performed in order to rule out other pathologies. Ultrasound is considered an effective, inexpensive, and accessible modality that can be part of the diagnostic evaluation of the superficial knee, including bursae. Magnetic resonance imaging (MRI) may be necessary for evaluation of intra-articular structures like menisci, ligaments, and cartilage.
A stretching and strengthening program should be used to correct predisposing biomechanical imbalances.
Patellofemoral Pain Syndrome (PFPS)
Patellofemoral Pain Syndrome (PFPS) is a term used to describe pain at the front of the knee and around or behind the kneecap (patella).
- Patellar tendinopathy (jumper’s knee). An overuse injury to the tissue connecting the kneecap to the shin bone (patellar tendon).
- Chondromalacia patellae (runner’s knee). A condition where the cartilage on the undersurface of the patella (kneecap) deteriorates and softens.
- Patellar tracking disorder (patellar maltracking). Abnormal tracking of the kneecap in the trochlear groove.
Management of PFPS should focus on progressively developing load tolerance of the tendon, the musculoskeletal unit, and the kinetic chain, as well as addressing key biomechanical and other risk factors.
Iliotibial band syndrome (ITBS)
Iliotibial band syndrome (ITBS) is a common knee injury that usually presents with pain and/or tenderness on palpation of the lateral aspect of the knee, superior to the joint line and inferior to the lateral femoral epicondyle.
The popliteus tendon is located at the deepest portion of the lateral knee and is intimately associated with other structures which comprise the posterolateral corner. The popliteus is often considered as a “popliteus complex”, referring to its attachments: the popliteofibular ligament, popliteomeniscal fascicles (attaching to lateral meniscus), and its attachment to the posterior joint capsule.
As a component of the posterolateral corner, the popliteus functions to resist:
- varus stress
- external tibial rotation
- posterior tibial translation
Tibiofemoral angular deformities in the frontal plane lead to mechanical axis deviation of the lower limb and malorientation of the joints above and below the level of deformity.
The 2 major types of tibiofemoral angular deformities are genu varum (bowlegs) and genu valgum (knock-knees).
- Genu varum. The degree of varus or valgus deformity can be quantified by the hip-knee-ankle angle, which is an angle between the femoral mechanical axis and the center of the ankle joint.
- Genu valgum. The degree of genu valgum can clinically be estimated by the Q angle, which is the angle formed by a line drawn from the anterior superior iliac spine through the center of the patella and a line drawn from the center of the patella to the center of the tibial tubercle.
- Genu recurvatum. Knee extension greater than 5°. Individuals who exhibit genu recurvatum may experience knee pain, display an extension gait pattern, and have poor proprioceptive control of terminal knee extension. A treatment program may include muscle imbalance correction, proprioceptive practice, gait, and functional training. Taping or knee bracing may be used initially to facilitate knee control.