Background
The knee is one of the most commonly injured body parts seen in physical therapy. The knee is a “hinge joint” and as such, the hinge allows the knee to bend and straight with very minimal rotation. The joint is made up of the femur, tibia, fibula, and the patella (knee cap). The patella is a part of the quadriceps muscle and rides up and down in a groove within the femur and tibia. Four major ligaments (ACL, PCL, MCL, LCL) provide stability to the joint during daily activities and sports.
Quick Links
ACL Injuries | Iliotibial Band Syndrome | Patello-femoral Pain Syndrome or Patellar Tendonitis | Knee Osteoarthritis (OA) & Total Knee Replacement
Diagnoses
ACL Injuries
Although this injury is commonly heard about in professional sports, an anterior cruciate ligament (ACL) tear is not a common injury. The ACL attaches from the femur to the tibia and restricts the tibia from moving in a forward direction. Mechanism of injury for an ACL tear can be hyperextension, planting and changing direction, and/or landing from a jump. Risk factors for tearing the ACL is being female, muscle imbalances between the quadriceps and hamstrings, and improper jumping and landing techniques (1).
An ACL tear is diagnosed with a clinical exam and confirmed through MRI or CT scans. Most ACL tears require surgery to either repair the ACL or provide a graft (either from another part of the body or a cadaver ACL). Physical therapy is important prior to surgery as research has demonstrated better results post-operatively when pre-operative strength and range of motion is increased (2). Post-operative physical therapy is a process that can take from 3-6 months depending on surgeon’s protocol and the person’s individual progress.
Physical therapy will focus on regaining full motion while protecting the surgical site. The physical therapist may use neuromuscular electrical stimulation (NMES) to quickly regain muscle strength of the quadriceps. While following the surgeon’s protocol, the physical therapist will progressively strengthen the muscles around the knee joint for a safe return to sports. Most importantly, the physical therapist will be able to use standardized tests and measures to ensure a safe return to sports and high level activities. >> top of page <<Iliotibial Band Syndrome
A common problem for both new and expert runners is problems with the iliotibial band (ITB). The ITB begins at the top outside of the hip as the tendon for the tensor fascia latae (TFL) and gluteus maximus muscles. It attaches below the knee at the tibia bone. The function of the ITB is to provide stability to the thigh muscles. Symptoms of ITB syndrome can be pain at the hip from friction of the ITB or at the outside knee from the ITB rolling over a bony protrusion. Symptoms are often exacerbated with higher level activities such as stairs, biking, or running. Some clinicians hypothesize that the ITB is too tight and causes friction. Others believe that muscle imbalances in the hip and knee lead to biomechanical changes during activities, resulting in added stretch of the ITB across the hip and knee. Physical therapists will work on reducing the stress of the ITB at the hip and knee as well as improving the muscle imbalances in the hip, knee, and core. ITB syndrome can linger for months to years if not corrected so stop waiting for it to “just go away”! >> top of page <<
Patello-femoral Pain Syndrome or Patellar Tendonitis
Patello-femoral pain syndrome (PFPS) is an umbrella term for general knee pain around the patella (knee cap) or the patellar tendon (a vertical tendon just below the knee cap). Pain is worse with higher level activities such as sitting to standing, walking long distances, ascending/descending stairs, and/or running/cycling. Even though there can be multiple etiologies for this pain, a physical therapy program focusing on manual therapy, progressive strengthening program, and improving biomechanics during activities is successful for PFPS.
Patellar tendonitis or patellar tendonopathy is pain localized to the bottom of the knee cap or the vertical tendon just below the knee cap. This pain is exacerbated with higher level activities such as stairs, running, cycling. Often times a physical therapy program for PFPS will resolve the symptom. However, an eccentric exercise program, a type of muscle activation that simultaneously contracts and lengths a muscle, may be necessary. This type of program has been demonstrated to be very effective for patellar tendonopathy (3). >> top of page <<Knee Osteoarthritis (OA) & Total Knee Replacement
The knee is one of the most common joints to experience osteoarthritis (OA) (4). OA is diagnosed either through a clinical exam or through an x-ray. An MRI may be warranted for further investigation of the soft-tissue structures in the knee such as menisci and ligaments. OA is a normal process in the body, most commonly effecting weight bearing joints that becomes worse as age. However, it has been shown that many people without pain can demonstrate degenerative changes in the knee (5). Physical therapy will focus on reducing swelling or inflammation (if present) with modalities such as ultrasound or electrical stimulation. Once the irritation of the joint is reduced, the goal is to strengthen all the muscles surrounding the joint. In the case of a physical therapy program doesn’t fully resolve symptoms, the next step is often a cortisone steroid injection. This is a discussion to have with either your primary care physician or the orthopedist as there can be contraindications to cortisone injections. If symptoms continue to be unresolved, a total knee replacement (TKR) may be appropriate. The TKR consists of replacing the surfaces of the femur (top bone) and the tibia (bottom bone) as well as the back surface of the patella (knee cap) with a metal material. By replacing the joint surfaces, pain is significantly reduced with activities such as walking, ascending/descending stairs, and squatting. It is important to begin physical therapy immediately after surgery, often in the hospital or at home if necessary. Once able to travel, an outpatient physical therapy program will focus on regaining the range of motion and the strength in the quadriceps muscle and surrounding hip and knee muscles. >> top of page <<
Sources
- Papoutsidakis A. Predisposing factors for anterior cruciate ligament injury. Br J Sports Med. 2011;45:2 e2. doi:10.1136/bjsm.2010.081570.5.
- Shelbourne KD, Gray T. Minimum 10-Year Results After Anterior Cruciate Ligament Reconstruction: How the Loss of Normal Knee Motion Compounds Other Factors Related to the Development of Osteoarthritis After Surgery. Am J Sports Med. 2009;37: 471-480.
- Frizziero A, Vittadini F, Fusco A, Giombini A, Gasparre G, Masiero S. Efficacy of eccentric exercise for lower limb tendinopathies in athletes. J Sports Med Phys Fitness. 2015.
- Cross M, Smith E, Hoy, D, et al. The global burden of hip and knee osteoarthritis: estimates from the global burden of disease 2010 study. Ann Rheum Dis. 2014 July; 73(7): 1323–1330.
- Stehling C, Lane NE, Nevitt MC, Lynch J, McCulloch CE, Link TM. Subjects with higher physical activity levels have more severe focal knee lesions diagnosed with 3 T MRI: analysis of a non-symptomatic cohort of the osteoarthritis initiative. Osteoarthritis and Cartilage. 2010; 18(6):776-786.