The purpose of this article is to give the reader a better understanding of an injury to a structure in the knee called the meniscus. It will include a description of what the meniscus is specifically as well as its purpose. Further discussion will include how meniscus injuries occur and how they are diagnosed by physicians, and possible surgical intervention. Future articles will discuss the role of physical therapy, the evaluation process, and physical therapy intervention.
What exactly are the menisci?
The menisci of the knee joint are two fibrocartilaginous wedges that divide the joint cavity. The medial meniscus is C-shaped and the lateral meniscus is O-shaped. The inner portion is thinner and concave, while the outer surface is convex and thicker. The menisci are connected to nerves, but they are avascular (no blood supply) except for the most peripheral outer zone. This essentially means that if a meniscus is torn pain is experienced, but there is no hemorrhaging in the joint. It also means that since there is no blood supply to the meniscus in general, they don’t heal well.
What do the menisci do? What purpose do they serve?
The menisci serve a variety of purposes including: Aid the ligaments in preventing the tibia from moving away from the femur; helping with lubrication of the knee joint; aid in shock absorption when walking, running, or jumping; distribute more than half the forces across the knee in weight-bearing; and act as spacers between the tibia and the femur.
How do meniscus injuries occur?
The most common mechanism of injury for the meniscus is quick direction changes. When a person puts weight on a bent or flexed knee and the tibia is externally rotated on the femur, the medial meniscus is moved to the center of the joint. An abduction movement can move the medial meniscus even further. The injury occurs when at the same time the medial meniscus is moved as far as it can normally move and a fall or a blow occurs to the lateral knee. At this time the medial meniscus is trapped between the femoral condyles and tibial plateau and overly compressed.
The different types of tears are bucket handle, longitudinal, horizontal, and parrot beak with bucket handle meniscal tears being the most common. Bucket handle tears often result in a locking effect where the knee can flex or bend, but cannot extend or straighten. This type of injury is the meniscal injury which most commonly occurs in young men playing football, soccer, hocky, and rugby.
Surgeons usually rely on a detailed examination of the knee including subjective and objective exams coupled with an MRI or arthrogram. Treatment from a surgeon’s perspective commonly comes with a partial meniscectomy, but increasingly a meniscal repair is warranted.
In summary this article described the structure of the meniscus and its function as well as its mechanism of injury. Also a brief summary of diagnosis and surgical intervention from a surgeon’s perspective were discussed briefly. Future articles relating meniscus repairs will be on physical therapy evaluation, indications and contraindications as well as physical therapy treatment to rehabilitate you from your meniscal injury!
**Call Peak Physical Therapy Today for a FREE ASSESSMENT!!**
Carlie Tobiason, PT - Eagle Idaho Physical Therapy Clinic
Bursitis Exercise Tips
Exercise #1: ITB Roll-Out
This exercise is designed to "massage" the tension out of your illiotibial band, which decreases the pressure being put on the bursa that surround the knee. This decrease in pressure lessens pain in the knee and allows the bursa to return to their normal state. Common household items that can be used include two tennis balls that have been taped together or a large sized frozen water bottle. See picture below.
Exercise #2 - Quad Stretch
This stretch should be felt in quadriceps on the the front of the thigh.
Stage 1: Lying on the edge of a bed, let one leg hang down toward the floor. Repeat on both sides for 30 seconds, 3 times per session.
Stage 2: While standing on one leg, with a hand-hold if needed, pull your heel toward your bottocks. Grab your foot with your hand and allow your quadriceps to stretch for about 30 seconds. Repeat 3 times per session.
Stage 3: Sitting on the floor with both legs straight, bend one leg and set your heel next to your hip. As comfort allows, slowly lean back until a stretch is felt in the quadriceps. Hold 20-30 seconds and repeat 3 times per leg.
Exercise #3- Hamstring Stretch
This stretch should be felt in the hamstrings on the back side of the thigh.
Stage 1: Lying on your back, place your hands behind your knee and slowly pull toward your chest while keeping your leg as straight as possible. Hold for 30 seconds and repeat 3 times.
Stage 2: Sitting on the floor with your legs straight, slowly reach toward your toes with both hands. Hold the stretch for 30 seconds and repeat 3 times.
Stage 3: Standing on one leg, SLOWLY reach toward the floor, pause, then SLOWLY return to a standing position. Repeat 10 times and attempt 2-3 sets per session.