A 28-year-old male had undergone an anterior cruciate ligament (ACL) reconstruction. During rehabilitation, there is restriction in the range of movement, inflammation of peripatellar soft tissue, extensor lag and a positive "shelf sign". What could be a potential diagnosis?

Question

Quizplus · Accepted Answer

Patella infera could be the diagnosis if the patient has painful restriction in the range of movement, inflammation of peripatellar soft tissue, extensor lag and a positive "shelf sign".
Patella infera or infrapatellar contracture syndrome results from hypertrophic healing response in the anterior soft tissue of the knee. It is known as infera because, in the lateral radiograph, the affected patella presents lower than the normal position. Effective quadriceps activity and knee flexion can be suggested to treat this condition. The quadriceps maintain the tension in the patellar tendon thereby limit the contracture of the tendon.
Patella alta (high riding of patella) is an abnormal high position of the patella. It may be secondary due to the patellar tendon rupture.
Global patella pressure syndrome and excessive lateral pressure syndrome are generally the features of "patella femoral compression syndrome".
Excessive lateral pressure syndrome is the presence of tightness only in the lateral retinacular structures.
Global patella pressure syndrome is associated with restricted mobility in medial and lateral directions and also often in the superior direction.

A 28-Year-Old Male Had Undergone an Anterior Cruciate Ligament (ACL)