Anterior Knee Pain Patellofemoral Stress Syndrome

One of the most common visits to our clinic is for anterior knee pain or pain around the knee cap. This occurs commonly in professionals who sit for long periods of time at a desk or have a long commute in a car (with a bent knee). Hamstring muscle length (back of thigh) shrinks over time in this setting and can lead to tightness. Additionally quads (front of thigh) are not being used and become weak over time. Either one of these problems can lead to increased pressure or stress under the knee cap and pain. This causes softening of the cartilage so that it becomes more water bed like and less memory foam like. This is sometimes called chondromalasia, which is softening or wear of the cartilage under the knee cap. It can happen to either the groove side (trochlea) or knee cap (patella).

This is a two part problem: 1. inflammation 2. biomechanics. The softening of the cartilage causes inflammation of the lining of the knee (synovium). This increases production of joint fluid and swelling occurs causing pressure and pain inside the knee. Inflammation is best addressed with either an NSAID (Non-Steroidal Anti-Inflammatory Drug), such as ibuprofen (brand names are Advil or Motrin) or naproxen (brand name is Aleve), and/or a steroid injection. Initially I suggest a course of NSAIDs (5-14 days taken regularly with food) and if this does not address the inflammation to return for a steroid injection in the knee. Some patients request an injection right away because of significant swelling and pain.

The muscle imbalance is addressed by strengthening the quad and stretching the hamstring. Quad strengthening is best done so that it does not aggravate the problem. Deep knee bends increase the pain behind the knee cap because it increases the stress or force there. Strengthening the quad muscles so that deep bending is avoided is important to avoid aggravating the problem. Straight leg raises where the knee is held straight and leg lifted with the knee held straight avoid pressure behind the knee cap and allow for quad strengthening. Also, short or shallow bend squats or leg presses where only a slight bend of the knee is done (45 degrees) will strengthen the quad and avoid pressure behind the knee.

One exercise to avoid is leg extensions where the bar is directing pressure on the shin dragging the knee cap backward – this causes increased stress behind the knee cap.

A knee brace or sleeve typically is not helpful if the brace compresses the knee cap against the groove, which increases stress there and pain. A better solution for increasing knee awareness (or proprioception) are sleeves that have a pocket that avoids pressing on the the knee cap or KT (kinesio tape) tape that is placed on either side of the knee cap, avoiding direct compression.