Article by Whitney Lowe
Introduction
One of the more common causes of anterior knee pain is a patellar tracking disorder, often referred to as patellofemoral pain syndrome or PFPS. This condition may be painful on its own, or lead to other painful problems such as chondromalacia patellae or osteoarthritis in the knee. Tracking problems are commonly a result of soft-tissue dysfunction. Consequently, massage therapy can play an important role in addressing this condition.
The Pathology
The knee is composed of two different joints: the articulation between the tibia and femur (tibiofemoral joint) and that between the patella and the femur (patellofemoral joint). Tracking disorders occur at the patellofemoral joint, so our discussion of biomechanics focuses on this area.
The patella is embedded within the tendon that attaches the quadriceps to the tibia. Because it is embedded in the tendon, the patella moves superiorly along the line of pull created by the quadriceps. The quadriceps group does not pull in a straight superior direction, but in a slight diagonal. This is because the quadriceps (with the exception of the rectus femoris) originate on the femur. The femur has a natural varus angulation so the quadriceps group pulls along this diagonal line. A varus angulation is one in which the distal end of the bone deviates toward the midline of the body. The degree to which this pull deviates from a straight vertical line is called the Q (quadriceps) angle.
The Q angle is determined by the intersection of two lines. The first line connects the tibial tuberosity with the midpoint of the patella. The second line connects the anterior superior iliac spine (ASIS) with the midpoint of the patella. The angle between the two lines is the Q angle and it determines the deviation from straight vertical that the quadriceps pull creates on the patella (Figure 1). Most individuals have some degree of femoral varus, so it is normal for the quadriceps to pull the patella laterally to some degree. Sources disagree on the how much of a Q angle is too much, but the majority indicate a Q angle greater than 150 for females and greater than 100 for males is excessive.1
The patella has a ridge down the middle of it, and this ridge must fit in the groove between the two femoral condyles (Figure 2). As the knee is extended, the patella moves in a superior direction and glides between the two femoral condyles. As the knee is flexed, the patella moves inferiorly. During movement, the ridge on the underside of the patella must stay centered between the femoral condyles. If it does not stay centered, a patellar tracking disorder could result. When the patella does not move correctly between the ridges created by the femoral condyles, excessive friction on the underside of the patella occurs. This friction may eventually cause the articular cartilage to soften and wear down – a condition called chondromalacia patellae.
Other structures around the knee joint, such as the quadriceps retinaculum and the fibrous joint capsule are richly innervated and may also be a source of pain. The medial and lateral sides of the patellar tendon have fibrous continuity with the joint capsule, and it is likely that excessive stress on the tendinous fibers may then pull on the capsule. Due to the rich innervation of tissues in this area, it doesn’t take much tensile force to cause pain.
Treatment approaches
Conservative treatment is generally preferred for PFPS. This is especially true if it is unclear as to which tissues are involved. Conservative treatment includes bracing, activity modification, patellar taping, and quadriceps strengthening exercises such as those that emphasize the vastus medialis obliquus (VMO). The VMO is the most distal portion of the vastus medialis muscle, whose fibers angle in an oblique direction to offset the lateral pull on the patella.
If conservative measures are not successful in alleviating the problem, surgery may be used. One of the common surgical procedures for this problem is the lateral retinacular release. In this procedure the lateral retinaculum is cut in order to decrease the amount of pulling on the extensor mechanism in a lateral direction. However, the effectiveness of lateral release surgery has been questioned.2 One reason may be that the optimal biomechanical balance around the joint is disturbed due to cutting important soft-tissue restraints around the knee.
Massage is very helpful for this condition because a significant part of the problem with PFPS is pain originating from the soft tissues around the knee. Changes may not be immediate as you are trying to alter biomechanical patterns that have been established for some time. However, the client should feel some improvement in symptoms within about 3-4 sessions.
Excess tension in the quadriceps is an important factor in PFPS, so massage methods aimed at reducing tension in the quadriceps are helpful. After more superficial warming techniques such as compressive effleurage, deep longitudinal stripping is effective for treating the quadriceps and retinacular tissues (Figure 3). Techniques like deep longitudinal stripping are helpful on the vastus lateralis to decrease its contribution to lateral patellar tracking.
Specific multi-directional friction techniques around the retinaculum are also helpful (Figure 4). Special attention should be paid to any area where the client reports greater pain, especially if that pain is consistent with the pain they have been feeling when doing activity.
Various fascial elongation methods applied to the quadriceps, and especially to the vastus lateralis are also valuable. Pin and stretch techniques are particularly effective here (Figure 5). In later stages, adding resistance to the eccentric action of the quadriceps during their elongation can enhance the active techniques further. Additional eccentric load can be added with resistance bands, weights, or with the practitioner’s hand. Stretching the quadriceps group is also very important during the rehabilitation process.
Conclusion
Due to its pathology, PFPS responds very well to massage. However, in order to derive the best therapeutic benefit from massage applications, the practitioner needs to understand patellofemoral mechanics and the role played by soft-tissues in this problem. When the anatomy, biomechanics, and massage options are understood, you can help many people alleviate this painful knee disorder.
*Portions of this article were originally published in Massage Magazine, Issue #112.
Notes
- Reider B. The Orthopaedic Physical Examination. Philadelphia: W.B. Saunders Company; 1999.
- Kolowich PA, Paulos LE, Rosenberg TD, Farnsworth S. Lateral release of the patella: indications and contraindications. Am J Sports Med. 1990;18(4):359-365.
