Lower Limb

Posterior cruciate ligament injury or PCL injury is less common than the anterior cruciate ligament injury.  A posterior cruciate ligament tear may result in disability ranging from no impairment to severe impairment. The primary function of the PCL is to prevent posterior translation of the tibia on the femur. The posterior cruciate ligament is also important […]

Genu recurvatum is a deformity in the knee  where the knee angulates backwards because of hyperextension occurs in the tibiofemoral joint [the knee goes further into extension beyond the neutral] Genu recurvatum is also called knee hyperextension and back knee. Depending upon hyperextension, the recurvatum could be mild, moderate or severe. The normal range of motion of the knee joint is from […]

Anterior cruciate ligament injury is a very common injury of the knee. It may occur in isolation or along with other soft tissue or bony injury of the knee. Anterior cruciate ligament injury or ACL injury most commonly results from a low velocity, noncontact deceleration injuries or pivoting injuries and contact injuries with a rotational […]

Trochlear dysplasia refers to a pathologic alteration in the shape of the femoral trochlea. Trochlea is also called facies patellaris, intercondylar groove, or intercondylar sulcus. Normal trochlea is sufficiently concave to guide and retain the patella throughout the normal range of movement. However trochlear dysplasia may cause the groove to be shallower than normal or […]

Patellar translation is the distance between tibial tubercle and trochlear groove and is also called TT-TG distance. It is measured on CT or MRI by overlapping or superimposing axial images of the femoral condyles and tibial tuberosity. The measurements are used to quantify patellar instability. The position of the tibial tubercle is crucial for the inferolateral force […]

Patellar instability or Patellofemoral instability is a frequent cause of symptoms of anterior knee pain and episodes of mechanical instability. It is also called patellar subluxation syndrome. There is a difference between symptoms of instability and patellar dislocation, though the former may cause the latter to happen. The term can denote a sign on physical examination or […]

Patella Baja or patella infera is an abnormally low lying patella [compare with patella alta, the high riding patella]. It is associated with a restricted range of motion, crepitations, and retropatellar pain. Patella baja could be congenital, acquired, or a combination of the two is commonly encountered in total knee arthroplasty. Any cause that would lead to […]

Patella alta, or a high riding patella, is a situation where the position of the patella is considered high in relation to distal femur. It may be idiopathic or may result secondary to an injury or disease process. The patella is up and above the knee joint instead of a normal position in the groove. As […]

Patellar height measurement becomes important in the diagnosis of patella alta and patella baja. Patella alta is a condition where the patella is high riding than its normal position. Patella baja refers to low lying position of the patella. Both conditions have been discussed separately. Measurement of patellar height can confirm or rule out the […]