SOFT-TISSUE DIFFERENTIAL DIAGNOSIS DIAGNOSIS AND MANAGEMENT OF ANTERIOR KNEE PAIN

The most common clinical conditions which have symptoms of AKP are: ● patellofemoral pain syndrome (PFPS) ● patella tendonitis ● plica syndrome ● fat pad syndrome ● traction apophysitis (Osgood Schlatter’s/Sinding Larsen Johansson)

● iliotibial band friction syndrome

For treatment of AKP to be successful, appropriate rehabilitation programmes are crucial. These can only be developed if accurate diagnosis of the underlying cause of the AKP is recognised.

This article will describe the common clinical conditions which present with AKP, to ascertain their differential diagnosis and outline their own particular management.

Differential diagnosis 1. PATELLOFEMORAL PAIN SYNDROME Definition: Pain associated with abnormal loading of the patellofemoral joint (PFJ). Cause: Mal-tracking of the patella which may stress the peri- patellar retinacular supports and the articular cartilage of the patellofemoral joint. This is often caused by abnormalities in lower limb alignment, in particular those which bring about a sig- nificant change in the Q angle (see figs.3a and 3b) Presentation: The patient frequently complains of pain behind the knee cap (retero-patella pain), though deep or posterior pain is not unusual. The pain is poorly localised and can vary from an ache to sharp pain depending on activity. The pain is aggravated

Vastus lateralis By Lee Herrington, MCSP Iliotibial tract/band

Anterior knee pain (AKP) is a common clinical occurrence in patients of all ages and activity levels. Any conditions involv- ing pain, inflammation, muscle imbalance and/or instability of any component of the extensor mechanism of the knee could be defined as AKP. Structures considered to be part of, or related to, the extensor mechanism of the knee are shown in figure 1.

Disturbance of the extensor mechanism of the knee has been regarded as one of the most common knee disorders affecting between 20% of the general population to 60% of an athletic population. Once present it frequently becomes a chronic problem forcing the patient to stop sport and other activities. The classi- fication of symptoms into AKP is difficult and confusing as AKP is present in many clinical conditions.

26 SportEX

Quadriceps femoris tendon

Lateral patella retinaculum

Infrapatella fat pad

Patella tendon Patella

Vastus medialis Rectus femoris

Medial patella retinaculum

©1999 Primal Pictures Ltd Figure 1: Structures that relate to the knee extensor mechanism