How to Deal With Anterior Knee Pain in the Active Young Patient

Abstract

Context: Anterior knee pain (AKP) represents the most common reason to consult with a clinician who specializes in the knee. Despite the high incidence of the disorder, however, its etiology is still controversial. Many unnecessary surgeries that may damage the patient are done for this clinical entity.

Evidence acquisition: A PubMed search from 1995 through June 2016.

Study design: Clinical review.

Level of evidence: Level 4.

Results: The etiology of AKP is multifactorial, and patients with AKP may therefore be divided into several subpopulations. The whole picture must be addressed for each patient to identify all potentially modifiable factors and to achieve better outcomes. Both pelvifemoral dysfunction and psychological factors that may affect the development and symptoms of AKP must be considered to identify therapeutic targets within the context of treatment. Patients presenting with AKP frequently respond well to load restriction that protects their knee and reduces pain during rehabilitation. Surgery should only be considered in very select cases. In a patient who has undergone previous patellar realignment surgery and experienced increased pain, iatrogenic medial patellar instability should be considered.

Conclusions: The etiology of AKP is multifactorial, and several subpopulations of AKP patients exist and their treatment must be personalized. Normally, the focus is on the knee of a patient with AKP, and only that joint is examined. However, that focus can lead to overlooking other important etiological factors that may be present.

Keywords: anterior knee pain; femoral torsion; homeostasis; patellofemoral pain; psychological factors.

Figure 1.

Anterior knee pain intensity is not related to the severity or the extension of the chondropathy of the patellae (arrow) found during surgery. In this particular patient, pain disappeared after an isolated arthroscopic partial synovectomy (asterisk) without specific treatment of the chondropathy.

Figure 2.

The envelope of function theory.^,

Figure 3.

Three-dimensional computed tomography demonstrating abnormal patellar tracking secondary to femoral internal rotation. On the right is a normal knee. The left shows how the rotating movement of the femur underneath the patella in the transverse plane leads to abnormal patellar tracking (1, lateral patellar subluxation and 2, patellar tilt). The patella maintains a horizontal position while the femur internally rotates; therefore, the patellar subluxation is not the result of patella moving on the femur but of the result of the femur rotating underneath the patella. 3, inward twisting of the knee. 4 (arrow), compression in the lateral patellofemoral joint increases. 5, retracted lateral retinaculum. 6, tension increases in the medial retinaculum. The final result is patellofemoral imbalance.