Anterior Knee Pain
The dozens of causes of anterior knee pain have been described for as long as doctors have examined athletes.
The potential solutions were just as numerous, if not more so.
Anterior knee pain, when not caused by trauma, is either mechanical or soft tissue-related. “Mechanical” means the muscle may be weak, the tracking of the kneecap in the groove of the femur (i.e, the trochlea) may be off, the hip-to-knee-to-foot angles are disordered, or the cartilage surfaces may be damaged. “Soft tissue” causes are often impingement on the underlying lining of the joint (often a scar band called a plica) or instability due to torn or lax ligaments.
If you have anterior knee pain, here are my top five things to look for and ways to think about treatment:
- Are the muscles weak? Testing by a trainer and/or physical therapist often initially identifies and treats this part of the problem. Strengthening the muscles improves the tracking of the patella in the trochlear groove and diminishes the loading on the patella cartilage.
- Is the kneecap unstable? A history of patella instability (often called subluxations or dislocations) is most often associated with weakness or tearing of the patellofemoral ligament, a key kneecap stabilizer leading from the patella to the femur. Once torn, it rarely heals well enough on its own. It can be repaired or reconstructed with a technique using two small incisions and a donor graft which minimizes any further damage to the knee. We have found this to be an extremely successful technique for often hyper-loose ballet dancers and gymnasts. On rare occasions they land awkwardly, dislocating the kneecap and tearing the stabilizing ligaments.
- Does the kneecap grind with knee bends and squats? Grinding can be due to soft tissue impingement, but it is often caused by articular cartilage damage. The articular cartilage is the white, shiny surface covering all bones in joints. When injured at the kneecap, it rarely heals. The damaged tissue frays, leading to the “crabmeat” appearance often shown in pictures as a precursor to more definitive arthritis, where the cartilage is worn entirely down to the bone.
The options for treatment are many. They include injections of growth factors (PRP) with lubricants (HA); surgical smoothing of the rough tissue; articular cartilage repair, using the paste graft technique we favor; realignment of the patellar tendon and lifting of the tendon insertion site to reduce the pressure on the cartilage; and partial joint replacement under robotic control. The bottom line: If the grinding is causing pain and swelling there is no reason to live with it and many reasons to treat it before it becomes a major problem.
- Is the cartilage completely gone, with the X-ray image showing bone-on-bone arthritis? If so, the best answer is often partial joint replacement. This technique was not routinely successful before the advent of robotics and 3D imaging, because the shape of each person’s groove on the femur (trochlear) is unique to their patella and mechanics. Three-dimensional imaging permits the implants to be placed on the model created from a CT scan of the bones and then adjusted at the time of surgery using real-time imaging. The results have been dramatically better, with patella femoral patients returning to Yoga, ballet, weightlifting, skiing, and other sports requiring significant kneecap loading.
- The age of anabolic injections, with recruitment factors for the body’s own stem cells, is upon us. We no longer inject cells to induce pain relief and reduce inflammation, as everyone has billions of stem cells within them and the effectiveness of using recruitment factors may be superior to injecting just a few million cells from bone, fat, or cells grown in the lab. Stay tuned to this space as research from our team—and many others—focuses on how we can stimulate the body to regenerate tissues while providing immediate pain relief.
The anterior knee pain story should be behind us as a cause for ruining people’s active lifestyles, but it still takes getting out in front of it
