Knee pain is one of the most common complaints patients present with in orthopaedic clinics, and can be extremely debilitating and chronic in a large percentage of this population. The bones around the knee include the femur (thigh bone), the tibia (shin bone), the patella (kneecap), and the fibula (outside leg bone). The joints of the knee include the tibiofemoral joint, the patellofemoral joint, and the proximal tibiofibular joint. Knee pain can come from any of these joints, as well as numerous other structures around the knee, including ligaments, the meniscii, bursae, fat pads, and muscles/tendons. Differentiating the structures which are causing a person’s knee pain can be difficult, but a physical therapist is highly qualified to evaluate patients with knee pain and help determine the best course of action to help decrease pain and return the patient back to normal function depending on the presenting pathology.
Common knee conditions seen in physical therapy include knee osteoarthritis, patellofemoral pain syndrome, and meniscal lesions. Knee osteoarthritis is defined as a narrowing of the cartilage in-between the bones of the knee. Cartilage is not neural, meaning it cannot cause pain; however, the bone underneath cartilage is higly neural, and knee pain from osteoarthritis occurs as the degeneration begins to cause increased stress to the underlying bone. Typically, this presents with pain during increased loading activities, such as long-distance walking, running, squatting, and stairs. It can also cause knee swelling, increasing pain during sitting or even while sleeping. Research has shown that conservative treatment of knee OA can improve pain and function, with interventions including weight control, range of motion exercises, joint mobilizations, lower extremity and core strengthening, and interventions aimed at other body regions which may be contributing to the patient’s knee symptoms.
Patellofemoral pain syndrome is known as pain around the patella, or retropatellar (behind the kneecap). Over 25% of patients presenting to physical therapy for knee pain are diagnosed with patellofemoral pain. It presents as pain during activities which increase stress in the patellofemoral joint, including stairs, squatting, running, biking, and sitting with the knee bent. The kneecap glides up/down in a groove formed on the distal femur as the knee is flexed and extended, and is connected to the quadriceps muscle proximally and the patellar tendon distally. The patella serves to improve the lever arm for a quadriceps muscle contraction, making it easier for the quadriceps muscle to function. Abnormal patellar tracking, or patellar malalignment, is thought to be a precursor for patellofemoral pain. Research is showing that abnormal mechanics around the patellofemoral joint, from the lumbar spine, pelvis, hip, knee, or ankle/foot can alter the forces acting on the patellofemoral joint, and contribute to anterior knee pain. A physical therapist will not only look at the knee joint, but also look up higher and lower in the body’s kinetic chain to see if underlying issues elsewhere may be contributing to the presenting knee pain.
The medial and lateral meniscus aide in load transmission through the knee, shock absorption, stress reduction, increased joint congruency, and improves the knee joint stability. Only the lateral 1/3 of the meniscus is vascular, meaning the location of the meniscal tear helps dictate its ability to heal, and this vascularity has been shown to decrease with age, making it even harder to heal later in life. Prior to understanding the role of the menisci, surgical procedures for meniscal lesions included complete removal of the meniscus, which vastly increased the amount of knee joint degeneration which occurred over time, prompting surgeons to look at less extensive interventions (including partial meniscectomies, or leaving the tear alone altogether). Meniscal lesions commonly occur with twisting/cutting maneuvers in sporting activities, or appear insidiously with increased aging (i.e. degenerative meniscal tear). Signs include clicking, popping, catching, knee joint swelling and warmth, decreased range of motion, and pain around the knee joint line. Research has shown that physical therapists are as good as an MRI in diagnosing meniscal tears, and recent research has also shown that conservative therapy for meniscal tears is as good for patient outcomes as surgery. More surgeons are taking a conservative approach initially with suspected meniscal tears, and allow conservative therapy (i.e. physical therapy) to maximize a patient’s outcomes prior to looking towards possible surgical intervention.
Though pain in the knee is common in our population, it does not have to become chronic and debilitating. Your physical therapist is highly qualified to evaluate your condition and help come up with a clinical diagnosis for your pain, while designing a plan of care to help improve your pain and function. The therapist will also look at what else may be contributing to your symptoms, and help prevent further problems down the road through an individualized treatment plan that fits your needs.